This disclosure generally relates to an automatic bicycle, particularly to a hydraulic automatic transmission bicycle which can automatically and adaptively change gear ratios. More particularly, this disclosure relates to those hydraulic automatic transmission bicycles which use fluid pressure to change such gear ratios, and which include various hydraulic automatic transmissions which may be provided in various configurations and may operate in various methods and sequences to provide automatic and Infinitely variable gear ratios.

BACKGROUND OF THE INVENTION

A conventional bicycle includes a chain gear between its front wheel and a rear wheel in order to allow a user to manually change gear ratios (or simply ‘change gears’). However, some circumstances render it very difficult for a user to change gears when a road condition changes so rapidly, and to maintain a proper speed even when the user succeeds in changing gears. An electrical bicycle may overcome such problems to some extent. However, the electrical bicycle requires expensive sensors to measure an rpm of a wheel, to monitor a slope of a road, and the like, and may also suffer from frequent malfunctions of such sensors, not to mention their high cost.

SUMMARY OF THE INVENTION

Various “hydraulic automatic transmission bicycles” (to be abbreviated as “HAT bicycles” hereinafter) of this disclosure include various “hydraulic automatic transmission” (to be referred to as “HAT” hereinafter) which may be provided in various configurations and which may operate in various mechanisms and sequences. Accordingly, a user of this HAT bicycle can change gear ratios and speeds of the bicycle without having to rely on prior art mechanical chain gears. A HAT bicycle may also minimize malfunctions of conventional mechanical chain gears, accidents caused by slipping chains or by jammed chains due to user's pants, and grease stains ruing pants of a user.

A hydraulic automatic transmission (HAT) bicycle of this disclosure may also include a HAT which in turn includes a hydraulic pump. The HAT may be configured to dispose all (or at least a substantial number of) elements of its driving part inside a housing of the HAT. Therefore, the HAT bicycle can minimize erosion or corrosion of such elements of the driving part caused by an environment (e.g., a rain, a snow, or salt spread on a road), and can also prevent dirt from entering the driving part, thereby minimizing malfunctions caused thereby. Because all (or most) elements of a driving part of the HAT are disposed inside a housing of the HAT, a user can also prevent his or her pants from contacting such elements of the driving part and from jamming the driving part. The HAT also includes a hydraulic motor which is driven by pressurized fluid which in turn is discharged from an outlet of a hydraulic pump, where all (or at least a substantial number of) elements of a driving part of such a hydraulic motor may similarly be disposed inside a housing of the HAT.

In addition, a hydraulic automatic transmission (HAT) bicycle of the disclosure may include a HAT which can automatically change gear ratios and which does not require manual manipulation by a user. Therefore, as the HAT bicycle may automatically and adaptively change gear ratios (or speed ratios) In response to changes in road conditions during operation, without requiring any manual manipulation from a user. Because such a HAT bicycle can change gear ratios automatically without requiring user manipulations to cope with such changes in road conditions, the HAT bicycle may minimize user inconveniences which may happen when the user misses an optimum timing of changing gears and cannot ride up a hill.

A hydraulic automatic transmission (HAT) bicycle of this disclosure also includes a HAT which may provide infinitely variable gear ratios. As a result, a user does not have to shift a gear to a 1stgear ratio in response to a change in road condition, and then has to shift to another 2ndgear ratio as the road condition changes again, for a HAT may automatically and adaptively shift a HAT bicycle to a certain gear ratio which is optimum to a certain road condition at that time and then shift to another gear ratio which is also optimum to a new road condition. Accordingly, a user may ride a HAT bicycle, without having to worry about responding to the road conditions which may change forever. Because a HAT bicycle provides infinitely variable gear ratios, such a bicycle neither has to mark or display a fixed number of multiple gear ratios, nor has to include a separate gear shift indicator representing a list of such fixed gear ratios. Accordingly, a user can ride a HAT bicycle without having to manipulate such gear ratios or gears at all.

A hydraulic automatic transmission (HAT) of a HAT bicycle of this disclosure may have a very short reaction time or a very short response time, for the HAT is manipulated by fluid pressure and, therefore, capable of shifting gears (or changing gear ratios) almost in real time in response to such changes in road conditions. It is appreciated that a pressure of fluid inside a HAT is generally synchronized with a pressure of fluid in a tube connected to the HAT in (almost) real time, as long as the tube does not include any valve or any part which block pressure communication therealong. Therefore, in contrary to conventional electrical automatic transmissions which at best electrically respond to changes in road conditions only after monitoring such conditions, the HAT of this disclosure can shift gears (or change gear ratios) using such fluid pressure and allow a user to ride a HAT bicycle with optimum gear ratios, while responding to changes in road conditions (almost) in real time. It is appreciated that a HAT with almost no response time may respond to changes in road conditions, mechanical load or mechanical resistance so rapidly such that a user may feel uneasy or uncomfortable. To obviate this problem, a HAT bicycle of this disclosure may dampen the timings or extents of such gear shifting (or gear ratio changing), e.g., by controlling fluid flow along the tube or by Impeding such fluid flow, thereby increasing a response (or reaction) time beyond a certain threshold value.

A hydraulic automatic transmission (HAT) of this disclosure may also include a conventional hydraulic pump (or motor) or may instead include a hydraulic pump (or motor) which is a variation or modification of such a prior art hydraulic pump (or motor) as will be described below. Accordingly, the HAT bicycle which includes such a HAT can be mass-produced at a low cost and which the HAT bicycle may not require any hydraulic pump (or motor) which operates under a brand new operating mechanism.

A hydraulic automatic transmission (HAT) bicycle of this disclosure may include a HAT which can perform various functions as described above or below but which may include a hydraulic pump (or motor) which can be used in a low rpm range. In particular, such a hydraulic pump (or motor) may be configured to operate in a low rpm range by slightly modifying or improving a configuration of a prior art hydraulic pump (or motor). As a result, a user may select optimum gear ratios and may ride a bicycle at a low range of rpms (e.g., 600 rpm, 400 rpm, and the like) which may match his or her body or health conditions.

In general, a hydraulic pump may be classified based on driving pressure such that a hydraulic pump operating in or beyond about 250 atm (atmosphere) is referred to as a “high-pressure hydraulic pump,” that a hydraulic pump operating between about 125 atm and about 250 atm is referred to as a “mid-pressure hydraulic pump,” and that a hydraulic pump operating in or under about 125 atm is referred to as a “low-pressure hydraulic pump.” In this respect, a HAT bicycle of this disclosure may typically include a low-pressure hydraulic pump or a mid-pressure hydraulic pump operating in a relatively low pressure range. Therefore, a HAT operating in a low to medium pressure range may reduce energy loss due to relatively low friction of various elements of a driving part of a HAT, and may therefore increase a driving efficiency of the HAT bicycle. Accordingly, a user may ride a HAT bicycle in gear ratios which match his or her physical or health conditions as well as which match varying road conditions, without exerting excessive force thereonto. Because a user does not exert excessive force thereon, a HAT bicycle may be free from excessive friction in its driving part and may also minimize malfunctions caused by erosion or fatigues. A HAT bicycle operating in a relatively low pressure range may only need a relatively thin housing such that a HAT bicycle may be made compact and light, at a low cost as well.

As a result, a hydraulic automatic transmission (HAT) bicycle of this disclosure may include a compact or light HAT. For example, such a HAT may be configured to have a size which is below a certain ratio (or percentage) of a size of a body (or a frame) of the HAT bicycle, or to have a weight which is below a certain ratio (or percentage) of a weight of a body (or a frame) thereof. Conversely, when a HAT bicycle is a heavy-duty bicycle, such a HAT bicycle may be configured to have a size or a weight which may exceed a certain ratio (or percentage) of a size of a body (or a frame) of a HAT bicycle or a weight thereof. In addition, a seat or a pedal of a HAT bicycle may be configured to match certain body parts of a user, while requiring a size or a weight of such a seat or pedal to be less than (or to exceed) a certain ratio (or percentage) of a size or a weight of a part of a HAT bicycle (or a user) as well. As a result, a HAT bicycle may be manufactured to have a size or a weight which may be comparable with those of a prior art bicycle with a chain gear, while improving a driving efficiency.

Although a hydraulic automatic transmission (HAT) bicycle of this disclosure may automatically shift gears and change gear ratios, such a HAT bicycle may be also configured to change a gear ratio as well, e.g., [1] when a magnitude of mechanical energy supplied to a HAT bicycle by a user exceeds a threshold value, [2] when mechanical load (or resistance) exerted onto a driving wheel (e.g., a front wheel, a rear wheel or both wheels) exceeds a threshold value, regardless of such mechanical energy applied by a user to the HAT bicycle, [3] when mechanical energy supplied by a user to a HAT bicycle in response to such mechanical load exceeds a threshold value, regardless of a magnitude of such mechanical resistance exerted onto the HAT bicycle, or [4] when mechanical energy supplied to fluid by a battery-operating electrical motor exceeds a threshold value.

A HAT bicycle may also be configured to change gear ratios, e.g., [1] when a fluid pressure inside a certain portion of a HAT bicycle exceeds a threshold value due to mechanical energy supplied thereto by a user, [2] when a fluid pressure inside a certain portion of a HAT bicycle exceeds a threshold value due to mechanical load (or resistance) exerted onto the driving wheel, regardless of such mechanical energy applied by a user to the HAT bicycle, [3] when a fluid pressure in a certain portion of a HAT bicycle exceeds a threshold value due to mechanical energy supplied by a user in response to the mechanical load, regardless of a magnitude of such mechanical resistance exerted onto the HAT bicycle, or [4] when a fluid pressure inside a certain portion of a HAT bicycle exceeds a threshold value due to such mechanical energy supplied to fluid by a battery-operating electrical motor.

A hydraulic automatic transmission (HAT) may also include various mechanical shift adjustors each of which may allow a user to manually control the above threshold value of a mechanical load, mechanical energy, or fluid pressure. Accordingly, a user may manipulate a shift adjustor in such a way that a HAT bicycle may change a gear ratio [1] when such mechanical load (or resistance) exceed a certain user-selected threshold, or [2] when a pressure of fluid entering a HAT (or inside a HAT) exceeds a certain user-selected threshold due to such mechanical load. Using such a shift adjustor properly, a user may render a HAT bicycle to shift gears on a hill when a user supplies only a certain amount of mechanical energy which matches his or her physical or health condition.

As described in the preceding paragraph, a HAT bicycle of this disclosure allows a user to manually exert a force onto a shift adjustor and to adjust such a threshold value. Alternatively and as will be explained below in greater detail, a HAT bicycle may allow a user to use an electrical unit to control such a shift adjustor and to select a desired threshold value, thereby shifting gears based on such a value. With this electrical device or with manual manipulation as described in the preceding paragraph, a user may control the shift adjustor in such a way that a HAT bicycle may change gears even with a small amount of mechanical energy which is applied by a senior person or by a young patient. In addition, the above electrical device may allow a user to replace a previously selected threshold value with a new value before or while riding a HAT bicycle for the convenience on the part of a user.

A user may instead manipulate the above shift adjustor of a HAT bicycle to change a gear ratio when such mechanical energy, mechanical load or pressure may exceed a certain maximum threshold value or, in the alternative, may fall below a certain minimum threshold value. Accordingly, when a user wants to improve his or her strength, the user may manipulate a HAT bicycle to shift gears only when the load, energy, or pressure exceeds the maximum threshold value. Conversely, when a user preferentially wants to use a HAT bicycle for commute, he or she may set up a HAT bicycle to shift gears as long as such a load, energy or pressure stays below a minimum threshold value.

A hydraulic automatic transmission (HAT) of this disclosure may also include a variable-volume (or a fixed-volume) hydraulic pump, and a variable-volume (or a fixed-volume) hydraulic motor. When a hydraulic pump unit of a HAT includes at least one variable-volume hydraulic pump, a hydraulic motor unit of the same HAT may include at least one variable-volume (or a fixed-volume) hydraulic motor therein. To the contrary, when a hydraulic pump unit of a HAT includes at least one fixed-volume hydraulic pump, a hydraulic motor unit of the same HAT may then include at least one variable-volume hydraulic motor so as to perform such automatic or adaptive transmission. Such a HAT may also include a variable-volume hydraulic pump as well as a variable-volume hydraulic motor, thereby expanding or maximizing a range of such gear ratios, where such a range typically spans from a minimum gear ratio to a maximum gear ratio.

A hydraulic automatic transmission (HAT) bicycle of this disclosure may include a hydraulic brake capable of stopping the bicycle or decreasing its speed, e.g., by stopping flow of a certain (or an entire) portion of fluid flowing into or out of a hydraulic pump, into or out of a hydraulic motor, or in other tubes. More particularly, such a hydraulic brake is configured to entirely or partially block a flow of fluid in an upstream of a hydraulic pump or motor, in a downstream thereof, of inside of such a hydraulic pump or motor. A HAT bicycle may use a hydraulic brake as the only brake or may use the hydraulic brake in conjunction with a conventional mechanical brake, where a user may optionally use such hydraulic and mechanical brakes concurrently or one at a time. Alternatively, a HAT bicycle may include both of the hydraulic and mechanical brakes and a user may recruit such brakes in such a way that, e.g., [1] when a user first activates a mechanical brake, a hydraulic brake may start to operate concurrently therewith or after a certain temporal gap or [2] when a user first activates a hydraulic brake, a mechanical brake may start to operate concurrently therewith or after a certain temporal gap. Thus, a user may have options of using one brake or both brakes concurrently or one after another depending upon situations, thereby stopping a HAT bicycle safely and efficiently.

A hydraulic automatic transmission (HAT) of this disclosure may be fabricated to be easily incorporated to a conventional bicycle. For example and as described above, such a HAT may be shaped or sized in a certain weight each of which may be comparable with that of a prior art bicycle and, therefore, may be conveniently mounted onto a prior art bicycle. In addition, a hydraulic pump unit and a hydraulic motor unit of a HAT may be fabricated to be implementable, e.g., between a pedal axis and a rotation axis of a rear wheel of a prior art bicycle. Therefore, mechanical energy supplied by a user into a pedal is transferred to a hydraulic pump of a hydraulic pump unit, and the hydraulic pump may pressurize a variable volume of fluid and deliver such fluid to a hydraulic motor unit. As a result, such a HAT may embody automatic and infinitely variable gear ratios. In addition, a hydraulic pump unit (or motor unit) may replace a pedal axis, a chain of a rear wheel, gear, or a rotation axis of a rear wheel, depending upon relative sizes or configurations thereof.

A hydraulic automatic transmission (HAT) bicycle of this disclosure may use a pedal or a pedal axis which may be identical to those of a prior art bicycle, and may also include a prior art chain gear which connects a rear wheel to the pedal axis. Accordingly, when a HAT bicycle employs a prior art pedal axis, the HAT bicycle may [1] mechanically couple a driving axis of a hydraulic pump unit (or its hydraulic pump) with the pedal axis either directly or indirectly, or [2] mechanically couple a driving axis of a hydraulic motor unit (or its hydraulic motor) either directly or indirectly. When a HAT bicycle employs a prior art chain (or its chain gear), the HAT bicycle may [1] mechanically couple a pedal axis with a driving axis of a hydraulic pump unit (or its hydraulic pump) with a prior art chain (or a chain gear), [2] mechanically couple a driving axis of a hydraulic motor unit (or its hydraulic motor) with a prior art chain (or a chain gear), or [3] mechanically couple a driving axis of a hydraulic pump unit (or its hydraulic pump) with a driving axis of a hydraulic motor unit (or its hydraulic motor) with a prior art chain (or a chain gear).

A hydraulic automatic transmission (HAT) of this disclosure may also be configured to be driven [1] solely by mechanical energy provided to its pedal by a user or [2] by such mechanical energy provided by the user and mechanical energy provided by an electrical motor which operates on a battery (or on an electrical generator which is operated by a user) concurrently, individually or one at a time. This arrangement allows a user to drive a HAT bicycle in a mechanical, manual driving mode or in an electrical driving mode, to switch from one mode to another mode, and the like, depending on user's need or road conditions.

A hydraulic automatic transmission (HAT) of this disclosure may also be fabricated as a unitary article, as a semi-unitary article, or as an assembly of multiple parts. In one example, a HAT may include a hydraulic pump unit (or its hydraulic pump), a hydraulic motor unit (or its hydraulic motor), and all (or at least a substantial number of) various tubes inside a cover of a HAT, thereby providing the single, unitary article. In another example, a HAT may include a substantial portion of a hydraulic pump unit (or its hydraulic pump), a substantial portion of a hydraulic motor unit (or its hydraulic motor), and a substantial portion but not all tubes inside the cover of the HAT, thereby providing a semi-unitary article. When the cover is made of or Includes sturdy material or when the cover is fabricated in a sturdy configuration, these configurations offer a benefit of mechanically protecting such units, motors, pumps or tubes contained inside the cover from external shocks or impacts.

Accordingly, various hydraulic automatic transmission (HAT) bicycles of this disclosure may be provided in various configurations as described hereinabove and hereinafter, and may be operated or used in various methods as described hereinabove and hereinafter. As a result, such HAT bicycles of this disclosure offer a user with various benefits or advantages such as, e.g., enhanced convenience, improved safety, and the like.

A hydraulic automatic transmission bicycle (HAT bicycle) of this disclosure includes therein various hydraulic automatic transmissions (HATs) in order to solve various problems or shortcomings associated with prior art bicycles by incorporating various configurations thereinto or by operating such HATs in various methods. Following portions of this disclosure provide further configurations of such HATs and bicycles incorporating such HATs, further methods of constructing such HATs and HAT bicycles, and further methods of using such HATs and HAT bicycles.

It is appreciated that a hydraulic automatic transmission (HAT) bicycle of this disclosure may be embodied in various exemplary “aspects” or may incorporate at least one of such “aspects” therein. It is also appreciated that each of such exemplary “aspects” may be embodied in various exemplary “embodiments” or may also incorporate at least one of such “embodiments” therein. It is further appreciated that each of such exemplary “embodiments” may be practiced in various “detailed examples (or simply ‘examples’)” or may also include at least one of such “examples” therein. Accordingly, following portions of this disclosure enumerate each of such exemplary aspects along with their exemplary embodiments, and those examples for each of such embodiments.

In one exemplary aspect A′ (i.e., an Aspect A′) of this disclosure, a HAT bicycle may include therein at least one hydraulic motor unit, at least one hydraulic pump unit, and at least one controller unit (or simply “control unit”), and is configured to change a gear ratio automatically (or adaptively) In response to an external mechanical load exerted onto at least a portion of such a HAT. As used herein, a “hydraulic pump (or motor) unit” collectively refers to a hydraulic motor unit or a hydraulic pump unit hereinafter. More particularly, such a hydraulic motor unit may pressurize fluid which is contained therein (up) to a certain pressure (to be referred to as a “motor pressure” hereinafter) in response to an (external) mechanical load which typically depends upon a road condition.

A hydraulic pump unit may pressurize fluid contained therein to a certain pressure which exceeds the above motor pressure (to be referred to as a “pump pressure” hereinafter) using mechanical energy provided thereto by a user. The hydraulic pump unit may then discharge such pressurized fluid to a hydraulic motor unit indirectly or directly, where the hydraulic pump unit may variably control a discharging volume (or a discharging flow rate) of such pressurized fluid depending upon at least one of various factors such as, e.g., the above mechanical energy, such motor pressure, such pump pressure, an rpm of the hydraulic motor unit, or an rpm of other units coupling with the hydraulic motor unit. A control unit may also control at least one of such motor pressure, such pump pressure, and variable discharging volume (or flow rate) of the hydraulic pump unit (or its hydraulic pump). Because the hydraulic motor unit may then take in the pressurized fluid from the hydraulic pump unit in such a variable discharging volume, an rpm of the hydraulic motor unit can be different from an rpm of the hydraulic pump unit, whereby the hydraulic pump unit and the hydraulic motor unit may provide such infinitely variable gear ratios.

In another exemplary aspect A″ (i.e., an Aspect A′) of this disclosure which corresponds to a variation of the above exemplary Aspect A′, a HAT bicycle may include at least one hydraulic motor unit, at least one hydraulic pump unit, at least one control unit, and at least one HAT, where the HAT is configured to change a gear ratio based on at least one of such external mechanical load, an rpm of the hydraulic motor unit, or an rpm of other parts coupling with the hydraulic motor unit. More particularly, the hydraulic motor unit may pressurize fluid contained therein to the motor pressure, while the hydraulic pump unit may pressurize fluid contained therein to the pump pressure which exceeds the motor pressure using mechanical energy provided by a user, and may then discharge the pressurized fluid to the hydraulic motor unit, where the hydraulic pump unit may variably control a discharging volume (or flow rate) of the pressurized fluid based on at least one of various factors such as, e.g., the above mechanical energy, such motor pressure, such pump pressure, an rpm of the hydraulic motor unit, or an rpm of other units coupling with the hydraulic motor unit. The hydraulic motor unit, the hydraulic pump unit, or the control unit is configured to directly or indirectly couple with a body of the bicycle. Accordingly, the hydraulic motor unit may take in a variable volume of the fluid discharged by the hydraulic pump and drives itself, thereby automatically changing a gear ratio from a 1strpm of the hydraulic motor unit and another 2ndrpm of the hydraulic pump unit which is different from the 1strpm.

As defined herein, an exemplary aspect A collectively refers to such an Aspect A′ as well as such an Aspect A′, and various embodiments of the Aspect A are as follows.

In one exemplary embodiment A-1 of this exemplary aspect A, a HAT or its hydraulic pump (or motor) unit may be configured as a light-weight HAT (or unit) or a heavy weight HAT (or unit) in proportion to a weight of a user, or that of a frame of a HAT bicycle. In one example, a HAT or its hydraulic pump (or motor) unit may be configured to weigh [1] less than about 13 kg, 11 kg, 9 kg, 7 kg, 5 kg or 3 kg, or [2] less than about 160%, 140%, 120%, 100%, 90%, 80%, 70%, 60%, 50%, 40% or 30% of a weight of the frame of the HAT bicycle. When the frame is made of or

Includes a light metal or a light composite material, the weight of the HAT or its hydraulic pump (or motor) unit may be less than about 230%, 210%, 190%, 170%, 150%, 130%, 110% or 90% of a weight of the frame of the HAT bicycle. Other details of a weight of the HAT or its hydraulic pump (or motor) unit may also be similar or identical to those of various embodiments of other aspects of this disclosure.

In another exemplary embodiment A-2 of this exemplary aspect A, a HAT or its hydraulic pump (or motor) unit may be configured as a large-sized transmission (or unit), as a medium-sized transmission (or unit), or as a small-sized transmission (or unit), in proportion to a size (e.g., a length or a height) of a user or a frame of a HAT bicycle. For example, a driving part of the hydraulic pump (or motor) unit may have a size which may be less than about 33 cm, 30 cm, 27 cm, 24 cm, 21 cm, 18 cm, 15 cm or 12, or may instead have a smaller size which may be less than about 13 cm, 11 cm, 9 cm, 7 cm or 5 cm when the HAT or its hydraulic pump (or motor) may be provided as a small-sized transmission (or unit). When the hydraulic pump (motor) unit may include a vane pump (or motor), a diameter of a rotor of the vane pump (or motor) may be less than about 32 cm, 29 cm, 26 cm, 23 cm, 20 cm, 17 cm, 14 cm, 11 cm, or 8 cm. However, when the hydraulic pump (or motor) unit may include a piston pump (or motor), a displacement of its driving part (i.e., its piston) may be less than about 32 cm, 29 cm, 26 cm, 23 cm, 20 cm, 17 cm, 14 cm, 11 cm, or 8 cm. In addition, when the hydraulic pump (or motor) unit includes a light-weight vane pump (or motor) or a light-weight piston pump (or motor), a diameter or a displacement of its driving part may be less than about 12 cm, 10 cm, 8 cm, 6 cm or 4 cm.

It is appreciated in the above paragraph that a size of the hydraulic pump (or motor) unit and its hydraulic pump (or motor) may correspond to its length or height depending upon an orientation of its installation and, therefore, the size may correspond to a long axis of the hydraulic pump (or motor). In addition, a thickness of the HAT, its hydraulic pump (or motor) unit or its hydraulic pump (or motor) may be less than about 130%, 110%, 90%, 70%, or 50% of a width of a seat of the HAT bicycle. A thickness of the HAT, its hydraulic pump (or motor) unit, or its hydraulic pump (or motor) may instead be less than about 150%, 130%, 110%, 100%, 90%, 80%, 70%, or 60% of a maximum distance between the pedals of the HAT bicycle. Details of such a size, a length, a height, or a thickness of the HAT or its hydraulic pump (or motor) unit may be similar or identical to those of various embodiments of other aspects of this disclosure.

In another exemplary embodiment A-3 of this exemplary aspect A, a HAT or its hydraulic pump (or motor) unit may be configured to have various volumes (or flow rates) in proportion to a body constitution of a user or to a mechanical load imposed by various road conditions. In addition and based thereon, the HAT or its hydraulic pump (or motor) unit may be classified into a high-volume HAT (or unit), a mid-volume HAT (or unit) or a low-volume HAT (or unit).

Alternatively, a HAT or its hydraulic pump (or motor) unit may be classified into a high-volume ratio HAT (or unit), a mid-volume ratio HAT (or unit) or a low-volume ratio HAT (or unit) according to a mechanical load which may be imposed by a road condition or which may be determined by a physical condition of a user. As used herein, a “volume ratio” is to be defined as a ratio of an Intake (or discharging) volume of a fluid by (or out of) a hydraulic motor unit (or its hydraulic motor) to an intake (or discharging) volume of a fluid by (or out of) a hydraulic pump unit (or its hydraulic pump). When a hydraulic pump (or motor) may be a variable-volume type, a maximum volume (or volume ratio) and a minimum volume (or volume ratio) may also be calculated. For example, the HAT or its hydraulic pump (or motor) unit is configured to have such a volume ratio which may be less than about 10.0 or, more particularly, less than about 5.0, about 4.0, about 3.0, between about 1.0 and about 2.0, between about 0.5 and about 1.0, between about 0.2 and about 0.5, between about 0.1 and 0.2, and the like. The HAT bicycle may also configure its hydraulic pump unit (or its hydraulic pump) or its hydraulic motor unit (or its hydraulic motor) to have relatively big volumes depending upon needs of a user.

In another exemplary embodiment A-4 of this exemplary aspect A, a HAT including one of such HATs may include a hydraulic pump (or motor) unit or its driving part capable of rotating in a high speed, a medium speed, or a low speed, according to the mechanical load or mechanical energy provided by a user. In one example, such a hydraulic pump (or motor) unit or its driving part may rotate at about 600 rpm in a very high speed riding, at about 200 rpm, 300 rpm, 400 rpm or 500 rpm in a high speed riding, between about 60 rpm and 200 rpm in a normal riding, and the like.

In another exemplary embodiment A-5 of this exemplary aspect A, a HAT or its hydraulic pump (or motor) unit may be classified into a high-pressure HAT (or unit), a mid-pressure HAT (or unit) or a low-pressure HAT (or unit) according to fluid pressure inside such a HAT (or unit) or pressure of a fluid discharging out of such a HAT (or unit) which may be determined according to such mechanical load, such mechanical energy, a weight of a user, and the like. For example, the HAT or its hydraulic pump (or motor) unit may operate in a range of pressure which may be less than about 130 atm, about 110 atm, about 90 atm, or about 70 atm.

In another exemplary embodiment A-6 of this exemplary aspect A, a HAT including one of such HATs may operate using mechanical energy provided by a user or mechanical energy supplied from an electrical motor. More particularly, when the HAT may include a control unit, its shift adjustor may be manipulated by mechanical energy provided by a user (e.g., manually by a user) or by mechanical energy provided from a battery through an electrical motor. In addition, a user may operate the HAT bicycle with mechanical energy provided to a pedal by a user. When the HAT bicycle Includes an electrical motor and a battery, a user may operate the HAT bicycle using such mechanical energy and using mechanical energy which is provided from the electrical motor operating on the battery. To this end, the HAT bicycle may include at least one switch which allows a user to select one of a “manual driving mode” and an “electrical driving mode” and to switch from one mode to another.

In another exemplary embodiment A-7 of this exemplary aspect A, a HAT bicycle with a HAT may include a cruise controller which may work in conjunction with an electrical motor and a battery. Accordingly, when a user is tired of manually rotating a pedal to supply mechanical energy thereto or when a user cannot keep up uphill to maintain a desired speed, a user may switch from a manual driving mode to an electrical driving mode, where an electrical motor drives the HAT bicycle without user's mechanical energy in such an electrical driving mode. To this end, a cruise controller may include a cruise switch which can turn on or off the cruise controller, a speed setting switch with which a user may select a driving speed, a reset switch with which a user may adjust a speed, and the like.

In another exemplary embodiment A-8 of this exemplary aspect A, when a HAT bicycle Including one of such HATs includes a battery and an electrical motor, the bicycle may include a prior art electrical generator, a prior art secondary battery, and the like. Therefore, when the battery is a rechargeable battery, the HAT bicycle may supply an electrical current or electrical voltage to recharge the battery while a user is riding the bicycle. In addition, the bicycle may use electrical energy from the generator or rechargeable battery in controlling various valves, pistons or switches of a control unit as described hereinabove and hereinafter. It is appreciated that the rechargeable battery may include a 1stswitch with which a user can turn such a battery on or off, a 2ndswitch with which a user can provide a certain portion of mechanical energy which he or she provides to the battery, and the like.

In another exemplary embodiment A-9 of this exemplary aspect A, a HAT bicycle including one of the above HATs may include a “forward clutch.” It is appreciated that, when a user may rotate a pedal in a forward direction (i.e., a “forward rotation”) in a HAT bicycle which does not include any forward clutch, fluid is pressurized in a hydraulic pump by mechanical energy which is supplied by a user and flows to a hydraulic motor. Therefore, the HAT bicycle may move in the forward direction. When a user rotates the pedal in an opposite, backward direction (i.e., a “backward rotation”), however, the fluid may not move in the backward direction and, therefore, the HAT bicycle may not move at all. In contrary, when a user rotates a pedal in the backward direction in a HAT bicycle with the forward clutch, such a forward clutch may prevent mechanical energy from being delivered to the hydraulic pump and, therefore, may allow a user to move a HAT bicycle in the forward direction. Such a forward clutch may be implemented into various locations of the HAT bicycle, where typical examples of the locations may include a driving axis of a hydraulic pump, a driving axis of a hydraulic motor, and the like.

Such a forward clutch may also be implemented to other locations of a HAT bicycle. In one example, the HAT bicycle may include at least one valve in or along one of various (fluid) tubes of the bicycle, where such a valve may allow a fluid to flow in one direction but may prevent the fluid flow in an opposite direction, and where examples of such valves may include a one-way valve, a check valve, and the like. Therefore, such a valve may function as the forward clutch as described above. In general, such a valve may be implemented into an inlet or an outlet of a hydraulic pump unit (or its hydraulic pump), an Inlet or outlet of a hydraulic motor unit (or its hydraulic motor), and the like, and function as the aforementioned forward clutch.

In another exemplary embodiment A-10 of this exemplary aspect A, a HAT bicycle with one of the above HATs may include at least one hydraulic brake in various locations of the bicycle and use the brake to slow down or to stop the bicycle. In one example, the HAT bicycle may implement at least one valve along at least one of various fluid tubes, along an inlet (or an outlet) of a hydraulic pump unit (or its hydraulic pump), along an inlet (or an outlet) of a hydraulic motor unit (or its hydraulic motor), and the like, and may utilize such a valve as the hydraulic brake, where examples of such valves may include a stop valve, a cock valve or other control valves capable of adjusting or blocking a fluid flow therethrough. In another example, the HAT bicycle may accomplish such braking in other means and utilize such means as the hydraulic brake in such a way that, e.g., the HAT bicycle may rapidly decrease fluid pressure in any portion of the HAT and may rapidly slow down or stop itself by rapidly bypassing pressurized fluid to a fluid tank from a tube, from a hydraulic pump (or motor) unit, or from a hydraulic pump (or motor).

It is appreciated that almost all of various valves described in the above embodiments are on-off valves or shut-off valves which may generally switch between an open position and a closed position and which may [1] allow fluid to flow therethrough or [2] stop such fluid flow. In contrary, a HAT bicycle may instead recruit various prior art control valves Instead of such on-off or shut-off valves and utilize such control valves as a hydraulic brake so that the control valves may adjust (or control) a flow rate therethrough, where examples of such control valves may Include a butterfly valve, a needle valve or other conventional valves which may operate not only in an open or closed position but also in at least one intermediate position. The HAT bicycle may also enhance braking by employing not only a prior art mechanical brake but also the above hydraulic brake. The HAT bicycle may also [1] manipulate the mechanical and hydraulic brakes to work concurrently with each other (e.g., when a user provides mechanical energy to one of such brakes, another brake also begins to work concurrently), or [2] manipulate one of such mechanical and hydraulic brakes to work first, and then manipulate another of such brakes to begin to work after a certain period of time. In addition, the HAT bicycle may configure such brakes to work concurrently or sequentially but in such a way that [1] both of such brakes may exert an identical or similar amount of mechanical energy to slow down or to stop the HAT bicycle, or [2] one of such brakes first begins to operate with a 1stamount of mechanical energy, and then another of such brakes begins to operate with a 2ndamount of mechanical energy which is greater than the 1stamount.

In another exemplary embodiment A-11 of this exemplary aspect A, a hydraulic pump (or motor) unit of a HAT may recruit various types of conventional pumps (or motors) such as, e.g., a vane pump (or motor), a gear pump (or motor), a piston pump (or motor), a screw pump (or motor), and the like. The hydraulic pump unit and a hydraulic motor unit may include an identical or similar type of a pump and a motor in such a way that, e.g., [1] the hydraulic pump unit may include a vane pump, while the hydraulic motor unit may include a vane motor, [2] the hydraulic pump unit may include a gear pump, while the hydraulic motor unit may include a gear motor, [3] the hydraulic pump unit may include a variable-volume vane pump, while the hydraulic motor unit may include a fixed-volume vane pump, and the like. Conversely, the hydraulic pump unit and the hydraulic motor unit may include a different type of a pump and a motor such that, e.g., the hydraulic pump unit may include a piston pump, while the hydraulic motor unit may include a gear motor.

In another exemplary embodiment A-12 of this exemplary aspect A, at least one of a hydraulic pump unit and a hydraulic motor unit may include at least one variable-volume pump or motor of various types. As a result, the hydraulic pump unit and the hydraulic motor unit may respectively include the variable-volume hydraulic pump and the variable-volume hydraulic motor. Conversely, the hydraulic pump unit may include a variable-volume hydraulic pump, while the hydraulic motor unit may include a fixed-volume hydraulic motor. Alternatively, the hydraulic pump unit may include a fixed-volume hydraulic pump, while the hydraulic motor unit may include a variable-volume hydraulic motor.

Other configurational or operational details of each of the above exemplary embodiments A-1 to A-12 of the exemplary aspect A may be similar or identical to those of other exemplary embodiments of this aspect A, or to those of other related exemplary embodiments of other aspects of this disclosure to be provided below.

In another exemplary aspect B′ (i.e., an Aspect B′) of this disclosure, a HAT bicycle may include at least one hydraulic motor unit, at least one hydraulic pump unit, and at least one control unit, thereby automatically changing gear ratios in response to mechanical load which is imposed by an external road condition. More particularly, the hydraulic motor unit may include at least one variable-volume (or fixed-volume) hydraulic motor each of which may apply mechanical energy onto fluid contained therein and to pressurize the fluid to the motor pressure in response to the mechanical load. The hydraulic pump unit may include at least one variable-volume hydraulic pump which may be configured to apply mechanical energy onto fluid contained therein, to pressurize the fluid to the pump pressure which may exceed the motor pressure, and then to discharge the pressurized fluid to the hydraulic motor, where a fluid volume which is discharged from the hydraulic pump unit (i.e., a discharging volume) may be manipulated or varied based on the mechanical load, the motor pressure or the mechanical energy. A HAT (or a user) may provide the control unit with at least one (control) set-point, where the control unit may vary such a discharging volume based on the set-point as well as based on at least one of the mechanical load, the motor pressure, the mechanical energy applied by a user, the pump pressure, an rpm of the hydraulic motor unit (or an rpm of its driving part), or an rpm of other parts coupled to the hydraulic motor unit, an rpm of the hydraulic motor (or an rpm of its driving part), as well as the set-point. Accordingly, the hydraulic motor unit may take in the fluid in an amount of the variable discharging volume which is discharged from the hydraulic pump unit, and may pressurize the fluid as described above, whereby such different rpms of the hydraulic pump unit and hydraulic motor unit may embody such automatic transmission (e.g., automatic gear ratio changing).

In another exemplary aspect B″ (i.e., an Aspect B″) of this disclosure which is a variation or a modification of the above Aspect B′, a HAT bicycle may include at least one hydraulic motor unit, at least one hydraulic pump unit, and at least one control unit, thereby automatically changing gear ratios in response to at least one of mechanical load imposed by an external road condition, an rpm of the hydraulic motor unit (or its driving part), and an rpm of another part coupling with the hydraulic motor unit. More particularly, such a hydraulic motor unit may include at least one hydraulic motor, where the hydraulic motor may pressurize fluid contained therein to the motor pressure in response to such mechanical load. The hydraulic pump unit may include at least one variable-volume hydraulic pump which may pressurize fluid contained therein to the pump pressure which exceeds the motor pressure using the mechanical energy supplied by a user and may discharge the pressurized fluid to the hydraulic motor, where a discharging volume of such pressurized fluid may be variable and depend upon at least one of the mechanical load, the motor pressure, the mechanical energy, an rpm of the hydraulic motor unit (or its hydraulic motor), an rpm of another part coupling with the hydraulic motor unit (or its hydraulic motor), and the like. The control unit may have its (control) set-point and may control such discharging volume based on at least one of the mechanical load, the motor pressure, the mechanical energy, the pump pressure, an rpm of the hydraulic motor unit (or its hydraulic motor), and an rpm of another part coupling with the hydraulic motor unit (or its hydraulic motor), as well as the set-point. In addition, at least one of the hydraulic motor unit, the hydraulic pump unit, and the control unit may be directly or indirectly couple with a body of the HAT bicycle. Accordingly, the hydraulic motor unit may take in a variable volume of the pressurized fluid and operate itself, thereby accomplishing such automatic gear changes due to different rpms of the hydraulic motor unit and the hydraulic pump unit.

As defined herein, an exemplary aspect B collectively refers to such an Aspect B′ as well as such an Aspect B″, and various embodiments of such an aspect B are as follows.

In one exemplary embodiment B-1 of this exemplary aspect B, a HAT bicycle including one of such HATs may configure the above control unit such that a user may not adjust or change a (control) set-point (e.g., a non-adjustable control set-point) or that a user may adjust such a (control) set-point (e.g., an adjustable control set-point). In another exemplary embodiment B-2 of this exemplary aspect B, the hydraulic pump (or motor) unit, its hydraulic pump (or motor) or the HAT may be configured as a light-weight unit (or HAT), as a regular-weight unit (or HAT), or a heavy-weight unit (or HAT) in proportion to a weight of a user or a frame of the HAT bicycle, as described above.

In another exemplary embodiment B-3 of this exemplary aspect B, the hydraulic pump (or motor) unit, the hydraulic pump (or motor), or the HAT may be configured to have a size (e.g., its length or height) to form a large-sized unit (or HAT), a medium-sized unit (or HAT), or a small-sized unit (or HAT), in proportion to a size (e.g., a length or a height) of a user or a frame of the HAT bicycle. For example, the hydraulic pump (or motor) unit, its hydraulic pump (or motor), or the HAT may be shaped or sized in a certain size or percentage as exemplified in the exemplary embodiment A-2 of the exemplary Aspect A. Alternatively and in another exemplary embodiment B-4 of this exemplary aspect B, the hydraulic pump (or motor) unit, the hydraulic pump (or motor), or the HAT may define an internal or external volume which may be classified into a high-volume unit (or HAT), a mid-volume unit (or HAT), or a low-volume unit (or HAT) based on various physical conditions of a user or a mechanical load imposed by a road condition. Alternatively, the hydraulic pump (or motor) unit, the hydraulic pump (or motor), or the HAT may instead be classified into a high-volume ratio unit (or HAT), a m id-volume ratio unit (or HAT), or a low-volume ratio unit (or HAT).

In another exemplary embodiment B-5 of this exemplary aspect B, a HAT bicycle including one of the above HATs may configure a driving part of its hydraulic pump (or motor) unit, of its hydraulic pump (or motor), or of its HAT to rotate in a high speed, in a medium speed, or in a low speed, based on such mechanical energy provided by a user, such mechanical load imposed by a road condition, and the like. For example, an rpm of the hydraulic pump (or motor) unit, of the hydraulic pump (or motor), or of the HAT may be similar or identical to those exemplified in the embodiment A-4 of the exemplary Aspect A. Alternatively and in another exemplary embodiment B-6 of this exemplary aspect B, a HAT bicycle including one of such various HATs may configure the hydraulic pump (or motor) unit, the hydraulic pump (or motor), or the HAT to operate as a high-pressure unit (or HAT), a mid-pressure unit (or HAT) or a low-pressure unit (or HAT) based on fluid pressure inside such a unit (or HAT) or fluid pressure discharged out of the unit (or HAT), a weight of a user, such mechanical energy or such mechanical load.

In another exemplary embodiment B-7 of this exemplary aspect B, a HAT bicycle as well as its HAT may be configured to operate with mechanical energy provided by a user or with mechanical energy supplied from at least one battery through an electrical motor, where further details of such a HAT bicycle or its HAT may be similar or identical to those exemplified in the embodiment A-6 of the exemplary Aspect A. Alternatively and in another exemplary embodiment B-8 of this exemplary aspect B, a HAT bicycle including one of the above HATs may include a “cruise controller” along with an electrical motor and a battery, where further details of such a HAT and its cruise controller may be similar or identical to those exemplified in the embodiment A-7 of the exemplary Aspect A. Alternatively and in another exemplary embodiment B-9 of this exemplary aspect B, a HAT bicycle Including one of such various HATs may include an electrical motor and a battery or may also include an electrical generator or a rechargeable battery.

In another exemplary embodiment B-10 of this exemplary aspect B, a HAT bicycle including one of the HATs may also include one of a mechanical forward clutch or a hydraulic forward clutch as previously exemplified in the embodiment A-9 of the exemplary Aspect A. Alternatively and in another exemplary embodiment B-11 of this exemplary aspect B, a HAT bicycle including one of such HATs may include at least one hydraulic brake in various tubes, or in various inlets (or outlets) of the above units or pumps (or motors), thereby slowing down or stopping the HAT bicycle.

In another exemplary embodiment B-12 of this exemplary aspect B, a hydraulic pump (or motor) unit may include various types of pumps (or motors), where further details of such pumps (or motors) may be similar or identical to those of the exemplary embodiment A-11 of the exemplary Aspect A. In addition, a HAT bicycle or its HAT of this exemplary embodiment (as well as other embodiments) of this exemplary Aspect B may include at least one variable-volume pump (or motor) in its hydraulic pump (or motor) unit.

Other configurational or operational details of each of the above exemplary embodiments B-1 to B-12 of the exemplary aspect B may be similar or identical to those of other exemplary embodiments of this aspect B, or to those of other related exemplary embodiments of other aspects of this disclosure provided hereinabove or to be provided hereinafter.

In another exemplary aspect C′ (i.e., an Aspect C′) of this disclosure, a HAT may incorporate at least one hydraulic pump, at least one hydraulic motor, and at least one control unit, and may automatically change its gear ratios according to mechanical load exerted from an exterior. More particularly, the hydraulic motor may pressurize fluid contained therein to the motor pressure according to the external mechanical load. The hydraulic pump may be one of a variable-volume vane pump, a variable-volume gear pump, or a variable-volume piston pump, each of which may vary its driving volume such that, e.g., a volume of fluid contained therein, a volume of fluid taken thereinto or discharged therefrom may vary, and the like. The hydraulic pump may pressurize fluid contained therein up to the pump pressure (which exceeds the motor pressure) with the mechanical energy, and then discharge the pressurized fluid to the hydraulic motor. The control unit may define a (control) set-point, and manipulate (or adjust) such a driving volume of the hydraulic pump based on at least one of the mechanical load, the motor pressure, the mechanical energy, the pump pressure, an rpm of the hydraulic motor, or an rpm of another part coupling with the hydraulic motor as well as based on the control set-point, thereby manipulating (or changing) a discharging volume from the hydraulic pump. As a result, the hydraulic motor takes in the pressurized fluid in a variable volume, and drives (or rotates) Itself in an rpm which may be different from an rpm of the hydraulic pump, thereby automatically changing gear ratios.

In another exemplary aspect C″ (i.e., an Aspect C″) of this disclosure which is a variation or a modification of the above Aspect C′, a HAT bicycle may include at least one hydraulic pump, at least one hydraulic motor, and at least one control unit, where a HAT of the HAT bicycle may automatically change its gear ratios based on at least one of mechanical load exerted from an environment (e.g., an external rod condition), an rpm of its hydraulic motor, or an rpm of another part coupling with the hydraulic motor. More particularly, the hydraulic motor may pressurize fluid contained therein to the motor pressure according to the mechanical load. The hydraulic pump may be a variable-volume vane pump, a variable-volume gear pump, or a variable-volume piston pump, each of which has a driving volume which may vary. The hydraulic pump may pressurize fluid contained therein with the mechanical energy supplied by a user to the pump pressure which exceeds the motor pressure, and discharge such pressurized fluid to the hydraulic motor. The control unit may define a (control) set-point, and may vary a driving volume of the hydraulic pump based on at least one of the mechanical load, the motor (or pump) pressure, the energy, an rpm of the hydraulic motor, or an rpm of another part coupling with the hydraulic motor, as well as based on the control set-point, thereby variably controlling the discharging volume of the hydraulic pump. The hydraulic motor, the hydraulic pump, and the control unit may also directly or indirectly couple with a body of the HAT bicycle. Accordingly, the hydraulic motor may take in the pressurized fluid from the hydraulic pump in a varying amount (or volume) and drive itself, and the rpm of the hydraulic motor (or unit) may become different from an rpm of the hydraulic pump (or unit), thereby automatically changing gear ratios while a user drives the HAT bicycle.

As defined herein, an exemplary aspect C collectively refers to such an Aspect C′ as well as such an Aspect C″, and various embodiments of such an aspect C are as follows.

In one exemplary embodiment C-1 of this exemplary aspect C, a control unit may not allow a user to vary its (control) set-point (i.e., an invariable or constant control set-point), or may allow a user to change such a (control) set-point (i.e., a variable control set-point). Alternatively and in another exemplary embodiment C-2 of this exemplary aspect C, a HAT bicycle may configure the hydraulic pump, the hydraulic motor, or the HAT as a light-weight pump, motor, or HAT, a medium-weight pump, motor, or HAT or a heavy weight pump, motor, or HAT, in proportion to a weight of a user, that of a frame of a HAT bicycle, and the like.

In another exemplary embodiment C-3 of this exemplary aspect C, a HAT bicycle may configure its hydraulic pump (or motor) or HAT to have a size (e.g., a length or a height) such as a large-sized pump (or motor) or HAT, as a medium-sized pump (or motor) or HAT, or as a small-sized pump (or motor) or HAT, in proportion to a size (e.g., a length or a height) of a user or a frame of a HAT bicycle or as a percentage of such a size of the user or the frame. Alternatively and in another exemplary embodiment C-4 of this exemplary aspect C, a HAT bicycle may configure its hydraulic pump (or motor) or its HAT to have an internal or external volume such as a large-volume (or large-volume ratio) pump (or motor) or HAT, a medium-volume (or medium-volume ratio) pump (or motor) or HAT, or a small-volume (or small-volume ratio) pump (or motor) or HAT, in proportion to a size (e.g., a length or a height) of a user or the mechanical load exerted by a road condition.

In another exemplary embodiment C-5 of this exemplary aspect C, a HAT bicycle may configure its hydraulic pump (or motor) or its HAT as a high-speed pump (or motor) or HAT, a medium-speed pump (or motor) or HAT, or a low-speed pump (or motor) or HAT, based on an rpm of such a pump (or motor) or HAT attained by the mechanical energy or the mechanical load. Alternatively and in another exemplary embodiment C-6 of this exemplary aspect C, a HAT bicycle may configure its hydraulic pump (or motor) or its HAT a high-pressure pump (or motor) or HAT, a medium-pressure pump (or motor) or HAT, or a low-pressure pump (or motor) or HAT, based on the pressure of the fluid contained therein or the pressure of the fluid discharged from the hydraulic pump (or motor) unit, from the hydraulic pump (or motor) or from the HAT, a weight of a user, the mechanical energy or the mechanical load.

In another exemplary embodiment C-7 of this exemplary aspect C, a HAT may be configured to operate with mechanical energy supplied by a user or with mechanical energy supplied from an electrical motor operating on a battery. A HAT bicycle with a HAT may similarly operate with mechanical energy supplied by a user or with mechanical energy supplied from an electrical motor operating on a battery. Alternatively and in another exemplary embodiment C-8 of this exemplary aspect C, a HAT bicycle with a HAT may include a cruise controller along with an electrical motor and a battery therefor. Alternatively and in another exemplary embodiment C-9 of this exemplary aspect C, a HAT bicycle with a HAT may also include an electrical motor and a battery, along with an optional generator or a rechargeable battery.

In another exemplary embodiment C-10 of this exemplary aspect C, a HAT bicycle with a HAT may include at least one forward clutch. Alternatively and in another exemplary embodiment C-11 of this exemplary aspect C, a HAT bicycle with a HAT may include at least one hydraulic brake incorporated into various areas or locations thereof in order to slow down or stop the bicycle during operation.

In another exemplary embodiment C-12 of this exemplary aspect C, a HAT may include various pumps (or motors) in its hydraulic pump (or motor) unit. Alternatively and in another exemplary embodiment C-13 of this exemplary aspect C, a hydraulic pump unit or a hydraulic motor unit of a HAT may include at least one variable-volume pump or motor.

In another exemplary aspect D′ (i.e., an Aspect D′) of this disclosure, a HAT of a HAT bicycle may include at least one vane pump, at least one hydraulic motor, and at least one control unit, and may automatically change gear ratios based on at least one of external mechanical load exerted thereonto. More particularly, a hydraulic motor may pressurize fluid contained therein to the motor pressure according to the external mechanical load. A vane pump may be disposed inside an outer cam ring, and may include a rotor which rotates about the driving axis and which is movable. The vane pump may pressurize fluid contained therein with the mechanical energy supplied by a user to the pump pressure exceeding the motor pressure, and discharge to a hydraulic motor the pressurized fluid in an amount which corresponds to a volume between the outer cam ring and the rotor. The control unit may define a (control) set-point, and may vary a discharging volume of the vane pump by manipulating a distance between a center of the outer cam ring and the driving axis of the vane pump, based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, and an rpm of the vane motor, as well as based on the control set-point. Thus, the hydraulic motor may take in the fluid discharged from the vane pump and automatically change gear ratios based on the difference between an rpm of the hydraulic pump and an rpm of the hydraulic motor, where the hydraulic motor may be another vane motor or of a different type.

In another exemplary aspect D″ (i.e., an Aspect D″) of this disclosure which is a variation or a modification of the above Aspect D′, a HAT of a HAT bicycle may include at least one vane pump, at least one hydraulic motor, and at least one control unit, and may automatically change gear ratios based on at least one of external mechanical load exerted thereonto, an rpm of the hydraulic motor, and an rpm of another part coupling with the hydraulic motor. In particular, a hydraulic motor may pressurize fluid contained therein to the motor pressure according to the external mechanical load. A vane pump may be disposed inside an outer cam ring, and may include a rotor which rotates about the driving axis and which is movable. The vane pump may pressurize fluid contained therein with the mechanical energy supplied by a user to the pump pressure exceeding the motor pressure, and discharge to a hydraulic motor the pressurized fluid in an amount which corresponds to a volume between the outer cam ring and the rotor. The control unit may define a (control) set-point, and may vary a discharging volume of the vane pump by manipulating a distance between the outer cam ring and the driving axis of the vane pump, based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, an rpm of the vane motor, and an rpm of at least one part coupling with the hydraulic motor, as well as based on the control set-point. In addition, at least one of the hydraulic motor, the vane pump, and the control unit may be directly or indirectly coupled to a frame of the HAT bicycle. Thus, the hydraulic motor may take in the fluid discharged from the vane pump and automatically change gear ratios based on the difference between an rpm of the hydraulic pump and an rpm of the hydraulic motor, where the hydraulic motor may be another vane motor or of a different type.

As defined herein, an exemplary aspect D collectively refers to such an Aspect D′ as well as such an Aspect D″, and various embodiments of such an aspect D are as follows.

In one exemplary embodiment D-1 of this exemplary aspect D, a control unit may not allow a user to vary its (control) set-point (i.e., an invariable or constant control set-point), or may allow a user to change such a (control) set-point (i.e., a variable control set-point). Alternatively and in another exemplary embodiment D-2 of this exemplary aspect D, a HAT bicycle may configure the vane pump, the hydraulic motor, or the HAT as a light-weight pump, motor, or HAT, a medium-weight pump, motor, or HAT or a heavy weight pump, motor, or HAT, in proportion to a weight of a user, that of a frame of a HAT bicycle, and the like.

In another exemplary embodiment D-3 of this exemplary aspect D, a HAT bicycle may configure its vane pump, its hydraulic motor, or HAT to have a size (e.g., a length or a height) such as a large-sized pump, motor, or HAT, as a medium-sized pump, motor, or HAT, or as a small-sized pump, motor, or HAT, in proportion to a size (e.g., a length or a height) of a user or a frame of a HAT bicycle or as a percentage of such a size of the user or the frame.

In another exemplary embodiment D-4 of this exemplary aspect D, a HAT bicycle may configure its vane pump, its hydraulic motor, or its HAT to have an internal or external volume such as a large-volume (or large-volume ratio) pump, motor, or HAT, a medium-volume (or medium-volume ratio) pump, motor, or HAT, or a small-volume (or small-volume ratio) pump, motor, or HAT, in proportion to a size (e.g., a length or a height) of a user or the mechanical load exerted by a road condition. Alternatively and in another exemplary embodiment D-5 of this exemplary aspect D, a HAT bicycle may configure its vane pump, motor, or its HAT as a high-speed pump, motor, or HAT, a medium-speed pump, motor, or HAT, or a low-speed pump, motor, or HAT, based on an rpm of such a pump, motor, or HAT attained by the mechanical energy or the mechanical load.

In another exemplary embodiment D-6 of this exemplary aspect D, a HAT bicycle may configure its vane pump, motor, or its HAT a high-pressure pump, motor, or HAT, a medium-pressure pump, motor, or HAT, or a low-pressure pump, motor, or HAT, based on the pressure of the fluid contained in the pump, motor or HAT, the pressure of the fluid which is discharged from such a pump, motor, or HAT, a weight of a user or a frame, the mechanical energy or the mechanical load. Alternatively and in another exemplary embodiment D-7 of this exemplary aspect D, a HAT may be configured to operate with mechanical energy supplied by a user or with mechanical energy supplied from an electrical motor operating on a battery or a generator. A HAT bicycle with a HAT may also operate with mechanical energy supplied by a user or with mechanical energy supplied from an electrical motor operating on a battery or a generator.

In another exemplary embodiment D-8 of this exemplary aspect D, a HAT may be configured to operate with mechanical energy supplied by a user or with mechanical energy supplied from an electrical motor operating on a battery. A HAT bicycle with a HAT and a cruise controller may similarly operate with mechanical energy supplied by a user or with mechanical energy supplied from an electrical motor operating on a battery. In the alternative and in another exemplary embodiment D-9 of this exemplary aspect D, a HAT bicycle with a HAT may include a cruise controller along with an electrical motor and a battery therefor.

In another exemplary embodiment D-10 of this exemplary aspect D, a HAT bicycle including one of such various HATs may include various forward clutches. Alternatively and in another exemplary embodiment D-11 of this exemplary aspect D, a HAT bicycle including one of such various HATs may include at least one mechanical or hydraulic brake to slow down or stop the HAT bicycle, where such a brake may be included in various locations along a path of fluid as exemplified above.

In another exemplary embodiment D-12 of this exemplary aspect D, a hydraulic pump (or motor) unit of a HAT may include various pumps (or motors) as exemplified above. Alternatively and in another exemplary embodiment D-13 of this exemplary aspect D, at least one hydraulic pump (or motor) unit of a HAT may include a variable-volume pump (or motor).

In another exemplary aspect E′ (i.e., an Aspect E′) of this disclosure, a HAT bicycle may include at least one hydraulic pump unit, at least one hydraulic motor unit, and at least one control unit, and may automatically change gear ratios in response to external mechanical load exerted thereonto. More particularly, a hydraulic motor unit may pressurize fluid contained therein to the motor pressure based on the external mechanical load, and discharge the pressurized fluid to a hydraulic motor, where the discharged volume is referred to as a motor discharging volume. The hydraulic pump unit may also pressurize fluid contained therein using mechanical energy provided by a user up to the motor pressure which exceeds the motor pressure and discharge the pressurized fluid to hydraulic motor unit, where the discharged volume is referred to as a pump discharging volume. The control unit may control at least one of the motor (or pump) pressure, the motor discharging volume, and the pump discharging volume. At least one of the hydraulic motor unit and the hydraulic pump unit may variably adjust its discharging volume based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, an rpm of a driving axis of the hydraulic motor unit, an rpm of another part coupling with the hydraulic motor unit, an rpm of a driving axis of the hydraulic pump unit, and an rpm of yet another part coupling with the hydraulic pump unit. Accordingly, an rpm of the hydraulic motor unit may become different from an rpm of the hydraulic pump unit, and the HAT bicycle can automatically change gear ratios based on the discharging volume of the hydraulic motor and pump units.

In another exemplary aspect E″ (i.e., an Aspect E″) of this disclosure which is a variation of the above aspect E′, a HAT bicycle may include at least one hydraulic pump unit, at least one hydraulic motor unit, and at least one control unit, and may automatically change gear ratios based on at least one of external mechanical load, an rpm of a driving axis of the hydraulic motor unit, an rpm of another part coupling with the hydraulic motor unit, and the like.

More particularly, the hydraulic motor unit may pressurize fluid contained therein to the motor pressure in response to the mechanical load, and discharge the pressurized fluid in an amount corresponding to the motor discharging volume. The hydraulic pump unit may also pressurize fluid contained therein to the pump pressure which exceeds the motor pressure using the mechanical energy supplied by a user, and discharge the pressurized fluid to the hydraulic motor unit in an amount corresponding to the pump discharging volume. In another example, the control unit may control at least one of the motor (or pump) pressure, the motor discharging volume, and the pump discharging volume. At least one of the hydraulic motor unit and the hydraulic pump unit may variably adjust its discharging volume based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, an rpm of a driving axis of the hydraulic motor unit, an rpm of another part coupling with the hydraulic motor unit, an rpm of a driving axis of the hydraulic pump unit, and an rpm of yet another part coupling with the hydraulic pump unit. More particularly, the hydraulic motor unit, the hydraulic pump unit, and the control unit may couple with a frame of the HAT bicycle indirectly or directly. Accordingly, an rpm of the hydraulic motor unit may become different from an rpm of the hydraulic pump unit, and the HAT bicycle can automatically change gear ratios based on the discharging volume of the hydraulic motor unit and the hydraulic pump unit.

As defined herein, an exemplary aspect E collectively refers to such an Aspect E′ as well as such an Aspect E″, and various embodiments of such an aspect E are as follows.

In one exemplary embodiment E-1 of this exemplary aspect E, a HAT bicycle may configure its hydraulic pump (or motor) unit, its hydraulic pump (or motor), or its HAT as a light-weight unit, pump (or motor), or HAT, as a regular-weight unit, pump (or motor), or HAT, or a heavy-weight unit, pump (or motor), or HAT based on a weight of a user or a frame of the HAT bicycle, as described above. In another exemplary embodiment E-2 of this exemplary aspect E, a HAT bicycle may configure its hydraulic pump (or motor) unit, its hydraulic pump (or motor), or its HAT as a large-sized unit, pump (or motor), or HAT, a medium-sized unit, pump (or motor), or HAT, or a small-sized unit, pump (or motor), or HAT, based on a size (e.g., a length or a height) of a user or a frame of the HAT bicycle or as a percentage thereof. In another exemplary embodiment E-3 of this exemplary aspect E, a HAT bicycle may configure its hydraulic pump (or motor) unit, its hydraulic pump (or motor), or its HAT as a high-volume unit, pump (or motor), or HAT, a mid-volume unit, pump (or motor), or HAT, or a low-volume unit, pump (or motor), or HAT, based on various physical conditions of a user or a mechanical load imposed by a road condition. Alternatively, the hydraulic pump (or motor) unit, the hydraulic pump (or motor), or the HAT may instead be classified into a high-volume ratio unit, pump (or motor), or HAT, a mid-volume ratio unit, pump (or motor), or HAT, or a low-volume ratio unit, pump (or motor), or HAT.

In another exemplary embodiment E-4 of this exemplary aspect E, a HAT bicycle may configure its hydraulic pump (or motor) unit, its hydraulic pump (or motor), or its HAT to rotate in a high speed, in a medium speed, or in a low speed, based on such mechanical energy provided by a user, such mechanical load Imposed by a road condition, and the like. Alternatively and in another exemplary embodiment E-5 of this exemplary aspect E, a HAT bicycle may configure its hydraulic pump (or motor) unit, its hydraulic pump (or motor), or its HAT to operate as a high-pressure unit, pump (or motor), or HAT, a mid-pressure unit, pump (or motor), or HAT, or a low-pressure unit, pump (or motor), or HAT, based on fluid pressure inside such a unit, pump (or motor), or HAT, fluid pressure discharged out of the unit, pump (or motor), or HAT, a weight of a user, such mechanical energy or such mechanical load.

In another exemplary embodiment E-6 of this exemplary aspect E, a HAT bicycle including such a HAT may be configured to operate with mechanical energy provided by a user or with mechanical energy supplied from at least one electrical motor operating on a battery or a generator. In another exemplary embodiment E-7 of this exemplary aspect E, a HAT bicycle including one of the above HATs may include a cruise controller along with an electrical motor and a battery. Alternatively and in another exemplary embodiment E-8 of this exemplary aspect E, a HAT bicycle including one of such various HATs may include an electrical motor and a battery or may also include an electrical generator or a rechargeable battery.

In another exemplary embodiment E-9 of this exemplary aspect E, a HAT bicycle including one of the HATs may include one of various mechanical or hydraulic forward clutches. In another exemplary embodiment E-10 of this exemplary aspect E, a HAT bicycle including one of various HATs may slow down or stop itself by Incorporating at least one hydraulic brake in various tubes, or in various inlets (or outlets) of the above units or pumps (or motors). In another exemplary embodiment E-11 of this exemplary aspect E, a HAT of a HAT bicycle may include at least one of various types of pumps (or motors) in the hydraulic pump (or motor) unit. In another exemplary embodiment E-12 of this exemplary aspect E, the hydraulic pump (or motor) unit may include at least one variable-volume pump (or motor).

In another exemplary aspect F′(i.e., an Aspect F′) of this disclosure, a HAT of a HAT bicycle may include at least one hydraulic pump, at least one hydraulic motor, and at least one control unit, and may change gear ratios automatically in response to external mechanical load which is exerted onto the HAT bicycle. More particularly, the hydraulic motor may pressurize fluid contained therein to the motor pressure based on the mechanical load. The hydraulic pump may define an internal driving volume, pressurize fluid contained therein up to the pump pressure (which exceeds the motor pressure) by operating its driving part with the mechanical energy supplied by a user, and discharge the pressurized fluid to the hydraulic motor unit in an amount corresponding to the driving volume (which may also correspond to the above pump discharging volume). The control unit may control the driving volume or the discharging volume from the hydraulic pump (or motor), by performing at least one of a linear (or translational) movement, a curved movement, or a rotational movement with respect to the driving part of the hydraulic pump (or motor) in synchronization with at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, an rpm of the hydraulic motor, or an rpm of another part coupling with the hydraulic motor. Because the hydraulic motor may take in the pressurized fluid discharged from the hydraulic pump, an rpm of the hydraulic motor may become different from an rpm of the hydraulic pump, and the HAT bicycle can automatically change gear ratios.

In another exemplary aspect F″ (i.e., an Aspect F″) of this disclosure which is a variation of the above aspect F′, a HAT of a HAT bicycle may include at least one hydraulic pump, at least one hydraulic motor, and at least one control unit, and may automatically change gear ratios based on at least one of mechanical load exerted by an external source (e.g., a road condition), an rpm of a driving axis of the hydraulic motor, and an rpm of another part coupling with the hydraulic motor. More particularly, the hydraulic motor may pressurize fluid contained therein to the motor pressure in response to the mechanical load. The hydraulic pump may define an internal driving volume, pressurize fluid contained therein up to the pump pressure (which exceeds the motor pressure) by operating its driving part with the mechanical energy supplied by a user, and discharge the pressurized fluid to the hydraulic motor unit in an amount corresponding to the driving volume (which may also correspond to the above pump discharging volume). The control unit may control the driving volume or the discharging volume from the hydraulic pump (or motor), by performing at least one of a linear movement, a curved movement, or a rotational movement with respect to the driving part of the hydraulic motor (or pump) in synchronization with at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, an rpm of the hydraulic motor, or an rpm of another part coupling with the hydraulic motor. The hydraulic motor, the hydraulic pump, or the control unit may be directly or indirectly couple with a frame of the HAT bicycle. Accordingly, the hydraulic motor may take in the pressurized fluid discharged from the hydraulic pump, and an rpm of the hydraulic motor may become different from an rpm of the hydraulic pump. As a result, the HAT bicycle can automatically change gear ratios.

As defined herein, an exemplary aspect F collectively refers to such an Aspect F′ as well as such an Aspect F′, and various embodiments of such an aspect F are as follows.

In one exemplary embodiment F-1 of this exemplary aspect F, a HAT bicycle may set the above control unit such that a user may not adjust or change a (control) set-point (e.g., a non-adjustable control set-point) or that a user may adjust the (control) set-point (e.g., an adjustable control set-point). In another exemplary embodiment F-2 of this exemplary aspect F, a HAT bicycle may configure the hydraulic pump (or motor) or the HAT as a light-weight pump, motor, or HAT, as a regular-weight pump, motor, or HAT, or a heavy-weight pump, motor, or HAT, based upon a weight of a user or a frame of the HAT bicycle. In another exemplary embodiment F-3 of this exemplary aspect F, a HAT bicycle may configure the hydraulic pump (or motor) or the HAT to have a certain size (e.g., a length, a height or a width) such as a large-sized pump, motor, or HAT, a medium-sized pump, motor, or HAT, or a small-sized pump, motor, or HAT, based on a size (e.g., a length or a height) of a user or that of a frame of the HAT bicycle, or based on percentages therebetween.

In another exemplary embodiment F-4 of this exemplary aspect F, a HAT bicycle may configure the hydraulic pump (or motor) or the HAT to define an internal or external volume which may be classified into a high-volume pump, motor, or HAT, a mid-volume pump, motor, or HAT, or a low-volume pump, motor, or HAT based upon various physical conditions of a user or a mechanical load imposed by a road condition. In the alternative, the hydraulic pump (or motor) or the HAT may be classified into a high-volume ratio pump, motor, or HAT, a mid-volume ratio pump, motor, or HAT, or a low-volume ratio pump, motor, or HAT. In another exemplary embodiment F-5 of this exemplary aspect F, a HAT bicycle may configure such driving parts of the hydraulic pump (or motor) or the HAT to rotate in a high speed, in a medium speed, or in a low speed, based on such mechanical energy provided by a user, or such mechanical load imposed by a road condition.

In another exemplary embodiment F-6 of this exemplary aspect F, a HAT bicycle may configure the hydraulic pump (or motor) or the HAT to operate as a high-pressure pump, motor, or HAT, a mid-pressure pump, motor, or HAT, or a low-pressure pump, motor, or HAT, based on fluid pressure inside such a pump, motor, or HAT, fluid pressure discharged out of the pump, motor, or HAT, a weight of a user, such mechanical energy or such mechanical load. In another exemplary embodiment F-7 of this exemplary aspect F, a HAT may operate with the mechanical energy provided by a user or with mechanical energy supplied from at least one electrical motor operating on a battery or a generator. In addition, the HAT bicycle Including one of the above HATs may also operate with the mechanical energy from a user or the mechanical energy from an electrical motor.

In another exemplary embodiment F-8 of this exemplary aspect F, a HAT may operate with the mechanical energy provided by a user or with mechanical energy supplied from at least one electrical motor operating on a battery. In addition, the HAT bicycle including one of such HATs may operate with at least one of such energies. In another exemplary embodiment F-9 of this exemplary aspect F, a HAT bicycle Including one of the above HATs may include a cruise controller along with an electrical motor and a battery

In another exemplary embodiment F-10 of this exemplary aspect F, a HAT bicycle including one of the HATs may include one of various mechanical or hydraulic forward clutches. In another exemplary embodiment F-11 of this exemplary aspect F, a HAT bicycle including one of various HATs may slow down or stop Itself by incorporating at least one hydraulic brake in various locations such as, e.g., in one of such tubes, in various Inlets (or outlets) of such pumps (or motors), and, the like.

In another exemplary embodiment F-12 of this exemplary aspect F, a HAT bicycle may include at least one of various types of pumps and at least one of various types of motors as its hydraulic pump and its hydraulic motor. In another exemplary embodiment F-13 of this exemplary aspect F, at least one of the hydraulic pump and the hydraulic motor may include at least one variable-volume pump or motor.

Other configurational or operational details of such HAT bicycles or their HATs of such exemplary aspects A to F may be similar or identical to those of such HAT bicycles or HATs of other exemplary embodiments of the same aspect or those of the HAT bicycles or HATs of other exemplary embodiments of different aspects. Variations or modifications of such configurations or operations of such HAT bicycles or their HATs of such exemplary aspects A to F may further be similar or identical to those of such HAT bicycles or their HATs of other exemplary aspects described hereinabove or to be explained hereinafter. In addition, at least a portion of such configurations or operations of such HAT bicycles or their HATs of such exemplary aspects A to F may replace, may be replaced by, may be combined into, or may be used with at least another portion of such HAT bicycles or their HATs of other exemplary aspects described hereinabove or to be explained hereinafter.

In another exemplary aspect H′ (i.e., an Aspect H′) of this disclosure, a HAT bicycle may include at least one frame and at least one HAT as described hereinabove. The frame may be shaped and sized to couple with at least one front wheel and at least one rear wheel, where the front wheel rotates about its axis of rotation, where the rear wheel rotates about its axis of rotation, and where the frame may also include at least two pedals which may be rotated about its axis of rotation by a user. The HAT may include at least one hydraulic pump, at least one hydraulic motor, and at least one control unit, and may automatically change gear ratios in response to external mechanical load. More particularly, the hydraulic motor may include a driving axis and a driving part, where the motor driving part may pressurize fluid contained in the hydraulic motor to the motor pressure by rotating about an axis of the motor driving part based on the mechanical load, and where the hydraulic motor may discharge the pressurized fluid in an amount of a motor discharging volume. The hydraulic pump may include a driving axis and a driving part, where the pump driving part may pressurize fluid contained in the hydraulic pump up to the pump pressure (which exceeds the motor pressure) by rotating about an axis of the pump driving part with the mechanical energy supplied by a user or with mechanical energy provided by an electrical motor operating on a battery, and may discharge the pressurized fluid to the hydraulic motor in an amount which is a pump discharging volume. The control unit may control the motor pressure, the pump pressure, or the discharging volume discharged from the hydraulic pump or from the hydraulic motor. The hydraulic motor or the hydraulic pump may variably adjust its discharging volume based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, and an rpm of the driving axis of the hydraulic motor. Accordingly, the hydraulic motor may take in the pressurized fluid discharged from the hydraulic pump, and an rpm of the hydraulic motor may become different from an rpm of the hydraulic pump. As a result, the HAT bicycle can automatically change gear ratios.

In another exemplary aspect H″ (i.e., an Aspect H″) of this disclosure which is a variation of the above aspect H′, a HAT bicycle may also include at least one frame and at least one of various HATs as described hereinabove or as will be described hereinafter. The frame may be shaped and sized to couple with at least one front wheel and at least one rear wheel, where the front wheel rotates about its axis of rotation, where the rear wheel rotates about its axis of rotation, where the frame may also include at least two pedals which may be rotated about its axis of rotation in response to the mechanical energy supplied thereto by a user, and where one of the axes of rotation of the front wheel and the rear wheel may correspond to a driving axis of the HAT bicycle. In addition, the HAT may change gear ratios by variably adjusting an rpm of the driving axis of the HAT bicycle in response to the mechanical load, and may include a cover into which at least 50% of a volume of the HAT may be Incorporated.

As defined herein, an exemplary aspect H collectively refers to such an Aspect H′ as well as such an Aspect H′, and various embodiments of such an aspect H are as follows.

In one exemplary embodiment H-1 of this exemplary aspect H, the HAT may include at least one cover, where such a cover may include or encompass therein at least 50% of a volume of the hydraulic pump, at least 50% of a long axis of the hydraulic pump, at least 50% of a volume of the hydraulic motor, or at least 50% of a long axis of the hydraulic motor, thereby protecting the hydraulic pump or the hydraulic motor from external shocks or impacts. In one example, a length of the cover may be less than about 75% of the long axis of the frame. The HAT may include multiple tubes therein, where the cover may include therein at least 50% of a total internal or external volume of such tubes, at least 50% of a total length of such tubes, and the like, thereby protecting such tubes from external impacts or shocks. The cover may also include at least substantial (or entire) portions of the hydraulic pump (or motor), thereby protecting the hydraulic pump (or motor) from external shocks or impacts.

The HAT may include at least one hydraulic pump and at least one hydraulic motor, where the hydraulic motor may define a driving axis and include a motor driving part. The motor driving part may rotate about its driving axis for pressurizing fluid contained therein to the motor pressure, and discharge the fluid therefrom in an amount of the motor discharging volume in response to the mechanical load. The hydraulic pump may define a pump driving axis and include a pump driving part, where the pump driving part may rotate about the pump driving axis in response to the mechanical energy, while pressurizing fluid contained therein to the pump pressure which exceeds the motor pressure, and where the pump driving part may discharge the fluid to the hydraulic motor in an amount of the pump discharging volume. At least one of the hydraulic motor and the hydraulic pump may variably adjust its discharging volume based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, and an rpm of the driving axis of the hydraulic motor. The HAT may then automatically change such gear ratios based upon a difference between an rpm of the hydraulic motor and another rpm of the hydraulic pump which may in turn be determined by the motor discharging volume and the pump discharging volume.

The hydraulic pump may be a vane pump, a gear pump, or a piston pump, while the hydraulic motor may be a vane motor, a gear motor, or a piston motor. The hydraulic pump may also be a variable-volume hydraulic pump, and the hydraulic motor may be one of a fixed-volume hydraulic motor or a variable-volume hydraulic motor. Conversely, the hydraulic pump may be one of a fixed-volume hydraulic pump or a variable-volume hydraulic pump, while the hydraulic motor may be a variable-volume hydraulic motor. The hydraulic pump and the hydraulic motor may be aligned in a direction of a long axis of a frame of the HAT bicycle or may instead be aligned transverse to the long axis of the frame. The HAT may include at least one control unit which control the motor pressure, the pump pressure, or the discharging volume discharged from the hydraulic pump or from the hydraulic motor based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, and an rpm of the driving axis of the hydraulic motor. Therefore, a user may manipulate the control unit to manually control the discharging volume of the hydraulic motor (or pump) or an extent of such automatic gear shifting (or changing).

In one exemplary embodiment H-2 of this exemplary aspect H, a HAT bicycle may configure the driving axis of the hydraulic pump to be the pedal axis, where the HAT bicycle may include at least one chain which mechanically couples the driving axis of the hydraulic motor with the rotation axis of the rear wheel. In another exemplary embodiment H-3 of this exemplary aspect H, a HAT bicycle may configure the driving axis of the hydraulic motor to be the rotation axis of the rear wheel, where the HAT bicycle may include at least one chain which mechanically couples the driving axis of the hydraulic pump with the pedal axis.

In another exemplary embodiment H-4 of this exemplary aspect H, a HAT bicycle may configure its HAT to have a length which may be less than about 50%, 60%, 70%, 80%, 90% or 100% of a length of the frame of the HAT bicycle. In another exemplary embodiment H-5 of this exemplary aspect H, a HAT bicycle may also be configured to have a length which may be less than about 50%, 60%, 70%, 80%, 90% or 100% of a distance from the rotation axis of the front wheel to the rotation axis of the rear wheel.

In another exemplary embodiment H-6 of this exemplary aspect H, the control unit may define at least one (control) set-point, and may variably control the discharging volume discharged from the hydraulic pump (or motor) based on the (control) set-point as well as based on at least one of the mechanical load, the motor (or pump) pressure, and the mechanical energy. The HAT bicycle may also allow a user to adjust the (control) set-point when desirable.

Each of various hydraulic pumps, hydraulic motors or HATs of this exemplary aspect H may be configured to have the weight, the size (e.g., a height, a length, or a width), the internal (or external) volume, the rpm, the driving (or discharging) volume, the internal pressure, or the pressure of the fluid discharged therefrom, each of which may be similar or identical to that of other exemplary aspects as described above or to be explained hereinafter. In addition, various types of such hydraulic pumps or hydraulic motors, inclusion of at least one variable-volume pump (or motor), inclusion of the shift adjustor, or the configuration or operational mechanism of the shift adjustor may be similar or identical to those of other exemplary aspects described above or to be explained below. Various HAT bicycles of this aspect H may also include at least one of such forward clutches or such hydraulic brakes, where such bicycles may operate with the mechanical energy supplied by a user or with mechanical energy supplied by an electrical motor operating on a battery.

In another exemplary aspect I′ (i.e., an Aspect I′) of this disclosure, a HAT bicycle may include at least one frame and at least one of such HATs. The frame may be shaped and sized to couple with at least one front wheel and at least one rear wheel, where the front wheel may rotate about its rotation axis, where the rear wheel may rotate about its rotation axis, and where the frame may also include at least two pedals which may be rotated about its axis of rotation by a user. The HAT may include at least one hydraulic pump, at least one hydraulic motor, and at least one control unit, and may automatically change gear ratios in response to external mechanical load. More particularly, the hydraulic motor may pressurize fluid contained therein to the motor pressure up to the motor pressure in response to the mechanical load. The hydraulic pump may include a driving part and a driving volume, where the hydraulic pump may operate the driving part with the mechanical energy supplied by a user or with mechanical energy provided by an electrical motor operating on a battery, while pressurizing fluid contained therein to the pump pressure (which exceeds the motor pressure), and where the hydraulic pump may discharge the pressurized fluid to the hydraulic motor in an amount which is a pump driving volume. The control unit may control the driving volume or the discharging volume from the hydraulic pump (or motor), by performing at least one of a linear movement, a curved movement, or a rotational movement with respect to the driving part of the hydraulic pump (or motor) in synchronization with at least one of the mechanical load, the motor (or pump) pressure, and the mechanical energy. Because the hydraulic motor may take in a variable volume of the pressurized fluid discharged from the hydraulic pump, an rpm of the hydraulic motor may become different from an rpm of the hydraulic pump, and the HAT bicycle can automatically change gear ratios.

In another exemplary aspect I″ (i.e., an Aspect I″) of this disclosure which is a variation of the above aspect I′, a HAT bicycle may include at least one frame and at least one of various HATs as described hereinabove or as will be described hereinafter. The frame may be shaped and sized to couple with at least one front wheel and at least one rear wheel, where the front wheel may rotate about its rotation axis, where the rear wheel may rotate about its rotation axis, where the frame may include at least two pedals which may be rotated about its rotation axis based on the mechanical energy supplied thereto by a user. The HAT may include at least one hydraulic pump, at least one hydraulic motor, and at least one control unit, and may also automatically change gear ratios in response to external mechanical load. More particularly, the hydraulic motor may include a motor driving axis and a motor driving part. The motor driving part may pressurize fluid contained therein to the motor pressure in response to the mechanical load by rotating about the motor axis, and may discharge the pressurized fluid in an amount of the motor discharging volume. The hydraulic pump may include a pump driving axis and a pump driving part, where the pump driving part may rotate about the motor driving axis with the mechanical energy supplied by a user, while pressurizing fluid contained therein to the pump pressure (which exceeds the motor pressure), and may discharge the pressurized fluid to the hydraulic motor in an amount which is a pump driving volume. The control unit may control the motor pressure, the pump pressure, or the discharging volume discharged from the hydraulic pump or from the hydraulic motor. The hydraulic motor or the hydraulic pump may variably adjust its discharging volume based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, and an rpm of the motor driving axis. Accordingly, the hydraulic motor may take in the pressurized fluid discharged from the hydraulic pump, and an rpm of the hydraulic motor may become different from an rpm of the hydraulic pump. As a result, the HAT bicycle can automatically change gear ratios.

As defined herein, an exemplary aspect I collectively refers to such an Aspect I′ as well as such an Aspect I′, and various embodiments of such an aspect I are as follows. In one example, the HAT may include at least one cover, where such a cover may include or encompass therein at least 50% of a volume of the hydraulic pump, at least 50% of a long axis of the hydraulic pump, at least 50% of a volume of the hydraulic motor, or at least 50% of a long axis of the hydraulic motor, thereby protecting the hydraulic pump or the hydraulic motor from external shocks or impacts. In another example, the HAT may include multiple tubes therein, where the cover may include therein at least 50% of a total internal or external volume of such tubes, at least 50% of a total length of such tubes, and the like, thereby protecting such tubes from external impacts or shocks. In addition, a length of the HAT may be less than about 75% of a length of a frame or about 75% of a distance between the rotation axis of the front wheel and the rotation of the rear wheel. The control unit may define a (control) set-point and may variably control the discharging volume of fluid discharged from the hydraulic pump (or motor) based on at least one of the mechanical load, the motor (or pump) pressure, and the mechanical energy. The HAT bicycle may also allow a user to manually adjust the (control) set-point.

In one exemplary embodiment I-1 of this exemplary aspect I, a HAT may include at least one cover which is similar or Identical to that of the exemplary aspect H. In another exemplary embodiment 1-2 of this exemplary aspect I, a HAT bicycle may configure the driving axis of the hydraulic pump (i.e., the pump driving axis) to be similar or identical to such an axis of the exemplary aspect H. In another exemplary embodiment 1-3 of this exemplary aspect I, a HAT bicycle may configure the driving axis of the hydraulic motor (i.e., the motor driving axis) to be similar or identical to that of the exemplary aspect H. In another exemplary embodiment 1-4 of this exemplary aspect I, a HAT bicycle may configure a length of the HAT as a certain percentage of the length of the frame, similar or Identical to that of the exemplary embodiment H-4 of the exemplary aspect H. In another exemplary embodiment 1-5 of this exemplary aspect I, a HAT bicycle may configure a length of the HAT as a certain percentage of the distance between the driving axis of the front wheel and the driving axis of the rear wheel, similar or identical to that of the embodiment H-5 of the exemplary aspect H.

In another exemplary embodiment 1-6 of this exemplary aspect I, a control unit of a HAT bicycle may have a (control) set-point, and may also variably control the discharging volume of the hydraulic pump (or motor) based upon the set-point as well as based upon at least one of the mechanical load, the motor (or pump) pressure, and the mechanical energy. The control unit may allow a user to manually or electrically adjust the (control) set-point.

Each of various hydraulic pumps, hydraulic motors or HATs of this exemplary aspect I may be configured to have the weight, the size (e.g., a height, a length, or a width), the internal (or external) volume, the rpm, the driving (or discharging) volume, the pressure therein, or the pressure of the fluid discharged therefrom, each of which may be similar or identical to that of other exemplary aspects described above or to be explained below. Various types of such hydraulic pumps or hydraulic motors, inclusion of at least one variable-volume pump (or motor), inclusion of the shift adjustor, or the configuration or operational mechanism of such a shift adjustor may be similar or Identical to those of other exemplary aspects described above or to be explained below. Various HAT bicycles of this aspect I may also include at least one of such forward clutches, and at least one of such hydraulic brakes, where such bicycles may operate with the mechanical energy supplied by a user or with mechanical energy supplied by an electrical motor operating on a battery.

In another exemplary aspect J (i.e., an Aspect J) of this disclosure, a HAT bicycle may include at least one frame and at least one of various HATs as described hereinabove or as will be described hereinafter. The frame may be shaped and sized to couple with at least one front wheel and at least one rear wheel, where the front wheel may rotate about its rotation axis, and where the rear wheel may rotate about its rotation axis. The HAT bicycle may also be shaped or sized to receive a pedal axis which may receive mechanical energy supplied by a user or may receive mechanical energy supplied by an electrical motor operating on a battery. In addition, the HAT bicycle may define a driving axis which may be one of a rotation axis of the front wheel and another rotation axis of the rear wheel. The HAT may automatically change gear ratios by varying an rpm of its driving axis using the mechanical energy and in response to the external mechanical load. The HAT bicycle may also include at least one cover which may include or encompass therein at least one half of an internal or external volume of the HAT, at least one half of a length of a long axis of the HAT, and the like, or which may have a length which may be less than about 50%, 60%, 70%, 80%, 90%, or 100% of a long axis of a frame of the HAT bicycle.

In one exemplary embodiment J-1 of this exemplary aspect J, a HAT of a HAT bicycle may include at least hydraulic pump and at least one hydraulic motor, where the hydraulic motor may include a driving axis (i.e., a motor driving axis) and a driving part (i.e., a motor driving part). The motor driving part may rotate about the motor driving axis in response the mechanical load, whereby the motor driving part may pressurize fluid contained therein to the motor pressure and discharge the pressurized fluid in a certain amount (i.e., a motor discharging volume). The hydraulic pump may include a driving axis (i.e., a pump driving axis) and a driving part (i.e., a pump driving part). The pump driving part may rotate about the pump driving axis in response to the mechanical energy supplied by a user (or mechanical energy supplied by a motor operating on a battery), whereby such a pump driving part may pressurize fluid contained therein to the pump pressure (which exceeds the motor pressure), and may discharge the pressurized fluid to the hydraulic motor in a certain amount (i.e., a pump discharging volume). In addition, at least one of the hydraulic motor and the hydraulic pump may variably adjust its motor discharging volume or pump discharging volume, respectively, based on at least one of the mechanical load, the motor (or pump) pressure, the mechanical energy, and an rpm of the hydraulic motor. Accordingly, the HAT may automatically change gear ratios by manipulating an rpm of the hydraulic motor and another rpm of the hydraulic pump, where such rpms may be determined by the motor (or pump) discharging volume.

In another exemplary embodiment J-2 of this exemplary aspect J, a HAT of a HAT bicycle may also include at least one control unit which may variably manipulate at least one of the motor (or pump) pressure, the pump discharging volume, and the motor discharging volume, based on at least one of the mechanical load, the pump (or motor) pressure, the mechanical energy, and an rpm of the hydraulic motor.

Each of various hydraulic pumps, hydraulic motors or HATs of this exemplary aspect J may be configured to have the weight, the size (e.g., a height, a length, or a width), the internal (or external) volume, the rpm, the driving (or discharging) volume, the pressure therein, or the pressure of the fluid discharged therefrom, each of which may be similar or identical to that of other exemplary aspects described above or to be explained below. Various types of such hydraulic pumps or hydraulic motors, inclusion of at least one variable-volume pump or motor, inclusion of the shift adjustor, or the configuration or operational mechanism of such a shift adjustor may also be similar or identical to those of other exemplary aspects described hereinabove or to be explained hereinafter. Various HAT bicycles of this aspect J may include at least one of the forward clutches, and at least one of the hydraulic brakes, where such HAT bicycles may operate with the mechanical energy supplied by a user or with mechanical energy supplied by an electrical motor operating on a battery.

In another exemplary aspect K (i.e., an Aspect K) of this disclosure, a HAT of a HAT bicycle may include at least one hydraulic pump, at least hydraulic motor, and at least one control unit, and may automatically change the gear ratios in response to external mechanical load imposed thereonto. The hydraulic motor may pressurize fluid contained therein to the motor pressure in response to the mechanical load. The hydraulic pump may pressurize fluid contained therein to the pump pressure (which exceeds the motor pressure) using the mechanical energy supplied by a user and may discharge such pressurized fluid to the hydraulic motor. More particularly, the hydraulic pump may be configured to have a variable driving volume (i.e., a pump driving volume) and may discharge a variable volume of the pressurized fluid (i.e., a pump discharging volume) to the hydraulic motor. The control unit may define a (control) set-point which may be adjusted by a user, and may variably manipulate the pump driving volume based on the (control) set-point as well as based on at least one of the mechanical load, the pump (or motor) pressure, and the mechanical energy, thereby also variably manipulating the pump discharging volume. Because the hydraulic motor may take in the pressurized fluid which is discharged from the hydraulic pump in the variable pump discharging volume, an rpm of the hydraulic motor may become different from an rpm of the hydraulic pump and, therefore, a user may variably change the gear ratios (or may select one of multiple variable gear ratios) either directly or indirectly.

In one exemplary embodiment K-1 of this exemplary aspect K, a hydraulic pump may be one of a variable-volume vane pump, a variable-volume gear pump, or a variable-volume piston pump. In another exemplary embodiment K-2 of this exemplary aspect K, a hydraulic motor may be one of a variable-volume hydraulic motor, and a fixed-volume hydraulic motor.

Each of various hydraulic pumps, hydraulic motors or HATs of this exemplary aspect K may be configured to have the weight, the size (e.g., a height, a length, or a width), the Internal (or external) volume, the rpm, the driving (or discharging) volume, the pressure therein, or the pressure of the fluid discharged therefrom, each of which may be similar or identical to that of other exemplary aspects described above or to be explained below. Various types of such hydraulic pumps or hydraulic motors, inclusion of at least one variable-volume pump (or motor), inclusion of the shift adjustor, or the configuration or operational mechanism of such a shift adjustor may be similar or identical to those of other exemplary aspects described above or to be explained below. Various HAT bicycles of this aspect K may also include at least one of such forward clutches, and at least one of such hydraulic brakes, where such bicycles may operate with the mechanical energy supplied by a user or with mechanical energy supplied by an electrical motor operating on a battery or a generator.

Other configurational or operational characteristics of various embodiments of the HAT bicycles or the HATs of each exemplary aspect H to K may be similar or identical to those corresponding embodiments of others of the aspects H to K, or may be similar or identical to other embodiments of other aspects described above or to be explained below. In addition, variations or modifications of various embodiments of the HAT bicycles or their HATs of the exemplary aspects H to K may be similar or identical to those variations or modifications of other aspects described above or to be explained below. At least a portion of such configurations or operations of such HAT bicycles or their HATs of the exemplary aspects H to K may also replace, may be replaced by, may be combined into, or may be used with at least another portion of such HAT bicycles or their HATs of other exemplary aspects described above or to be explained below.

In another exemplary aspect P (i.e., an Aspect P) for various HAT bicycles of this disclosure, a method may provide various benefits to a user and may include the steps of: determining a pump pressure of fluid to be discharged out of a hydraulic pump unit (or its hydraulic pump) based on mechanical load exerted from an external source such as a road condition (e.g., a pressure determination step); driving the hydraulic pump unit (or its pump) at a pump rpm and pressurizing the fluid contained therein to the pump pressure (e.g., a pressurizing step); automatically varying a driving volume of the hydraulic pump according to discharging pressure from the hydraulic pump and delivering a variable discharging volume to the hydraulic motor (e.g., a discharging controlling step); changing gear ratios by generating power and driving the hydraulic motor with the power at a motor rpm determined by the discharging volume of the hydraulic pump (e.g., a step of changing gear ratios); and allowing a user to select one of a first control set-point for an extent of such changing gear ratios and a second control set-point for a response time for such changing a gear ratio in response to changes in such mechanical load (e.g., a user control step).

Various exemplary embodiments of various methods exemplified in the Aspect P may Include the following. The pressurizing step may include the step of increasing the discharging pressure from the hydraulic pump in proportion to an increase in the mechanical load. The discharging controlling step may include the step of controlling the discharging pressure from the hydraulic pump inversely proportional to the driving volume of the hydraulic pump. The discharging controlling step may also include the step of including at least one of a variable-volume vane pump, a variable-volume gear pump, and a variable-volume piston pump as such a hydraulic pump. The step of changing gear ratios may include the step of including at least one of a variable-volume hydraulic motor and a fixed-volume hydraulic motor as the hydraulic motor.

The step of changing gear ratios may include one of the steps of: automatically determining an rpm of the hydraulic motor based on such discharging volume of the discharging volume of the hydraulic pump; and automatically determining an rpm of the hydraulic motor according to one of the discharging volume of the hydraulic pump and such mechanical load. In addition, the method may include the step of incorporating at least 50% of the hydraulic pump and at least 50% of the hydraulic motor inside a cover of the HAT (e.g., a consolidating step). More particularly, the method may include a first aligning step of aligning the hydraulic pump and the hydraulic motor along their long axes and then hydraulically coupling each other, or may include a second aligning step of aligning the hydraulic pump and the hydraulic motor in a direction which is transverse to their long axes and then hydraulically coupling each other. The user control step may include the step of controlling at least one of the first control set-point and the second control set-point while a user operates the hydraulic pump.

In another exemplary aspect Q (i.e., an Aspect Q) for various HAT bicycles of this disclosure, a method may protect a HAT bicycle or its HAT from external shock (or impact) and may include the steps of: pressurizing fluid contained in a hydraulic pump by driving a hydraulic pump according to mechanical load exerted by an external source (e.g., a road condition) and then delivering a variable volume of the pressurized fluid to a hydraulic motor while controlling a driving volume of the hydraulic pump according to the pressure of the fluid discharged from the hydraulic pump (e.g., a step of pump discharging control); generating mechanical energy by driving the hydraulic motor at a motor rpm with the pressurized fluid delivered from the hydraulic pump and changing gear ratios determined by the rpm of the hydraulic motor and that of the hydraulic pump (e.g., a step of controlling gear ratios); and protecting the hydraulic pump and the hydraulic motor from an external impact or shock by incorporating at least 50% of a volume of each of the hydraulic pump and the hydraulic motor inside a cover of the HAT bicycle (e.g., a protecting step).

Various exemplary embodiments of various methods exemplified in the Aspect Q may Include the following. The step of pump discharging control may include one of the steps of: increasing the pressure of the fluid which is discharged from the hydraulic pump as the mechanical load increases; and controlling the pressure of the fluid discharged by the hydraulic pump inversely proportional to a driving volume of hydraulic pump. The step of pump discharging control may also include the step of configuring the hydraulic pump as one of a variable-volume vane pump, a variable-volume gear pump, and variable-volume piston pump, while the step of controlling gear ratios may include the step of configuring the hydraulic motor as one of a variable-volume hydraulic motor and a fixed-volume hydraulic motor.

In addition, the step of controlling gear ratios may include one of the steps of: automatically determining an rpm of the hydraulic motor based on the discharging volume of the fluid discharged from the hydraulic pump; and determining a variable rpm of the hydraulic motor based on the discharging volume or the mechanical load. The method may include one of third aligning steps of: aligning the hydraulic pump and the hydraulic motor along a common long axis one after another and hydraulically coupling each other, and aligning the hydraulic pump and the hydraulic motor in a direction transverse to their long axes and hydraulically coupling each other. The method may also include a user control step of allowing a user to select one of a first control set-point for an extent of such changing gear ratios and a second control set-point for a response time for such changing a gear ratio in response to changes in such mechanical load.

Other operational details of such exemplary embodiments of the exemplary aspect P and exemplary aspect Q may be similar or identical to their corresponding exemplary embodiments, or to those of other related exemplary embodiments (including their modifications or their variations) of other aspects of this disclosure provided hereinabove or to be provided hereinafter. In addition, at least a portion of such configurations or operations of such HAT bicycles or their HATs of the exemplary aspects P and Q may also replace, may be replaced by, may be combined into, or may be used with at least another portion of such HAT bicycles or their HATs of other exemplary aspects described above or to be explained below.

In another exemplary aspect R (i.e., an Aspect R) for various HAT bicycles of this disclosure, a method may provide a HAT bicycle which may allow a user with hydraulic and infinitely variable gear ratios. The method may include the steps of: synchronizing mechanical load from an external source with a hydraulic motor so as to pressurize fluid contained in the hydraulic motor to a motor pressure (e.g., a load synchronizing step); synchronizing energy mechanically supplied by a user or mechanical by an electrical motor operating on a battery with a hydraulic pup in order to pressurize fluid contained in the hydraulic pump to a pump pressure which exceeds the pump pressure (e.g., a pressure synchronizing step); discharging the pressurized fluid from the hydraulic pump to the hydraulic motor in an amount of a pump discharging volume (e.g., a pump discharging step); and taking in the pressurized fluid discharged from the hydraulic pump by the hydraulic motor and then rotating a motor driving axis of the hydraulic motor while discharging the pressurized fluid from the hydraulic motor in an amount of a motor discharging volume (e.g., a driving step). The method may include at least one of the steps of: manipulating at least one of the mechanical load, the motor pressure, the pump pressure, and the mechanical energy (e.g., a user manipulating step); variably manipulating at least one of a first driving volume of the hydraulic motor (i.e., a motor driving volume) and a second driving volume of the hydraulic pump (i.e., a pump driving volume) by performing of at least one of the load synchronizing and the pressure synchronizing as a result of the user manipulating step (e.g., a delivery synchronizing step); discharging the pressurized fluid in a variable volume which may be one of the motor discharging volume and the pump discharging volume due to at least one of the variable motor driving volume and the variable pump driving volume (e.g., a variable discharging step); and changing at least one of the motor discharging volume and the pump discharging volume as a result of the variable discharging step, thereby automatically changing the gear ratios (e.g., a gear changing step).

Various exemplary embodiments of various methods exemplified in the Aspect R may include the following. The method may include the step of enclosing at least a portion of the hydraulic pump and the hydraulic motor inside a cover of the HAT bicycle for protecting such a portion from external shocks or Impacts (e.g., a protecting step). The protecting step may also include at least one of the steps of: configuring said portion to be at least 50% (or 60%, 70%, 80%, 90% or more) of a volume of at least one of the hydraulic pump and the hydraulic motor and enclosing at least 50% (or 60%, 70%, 80%, 90% or more) of a sum of lengths of fluid tubes inside the cover. The protection may instead include at least one of the steps of: configuring the cover to have a length which may be less than about 70% (or 60%, 50%, 40%, 30% or less) of a length of the HAT bicycle; and configuring the length of the cover to be less than about 70% (or 60%, 50%, 40%, 30% or less) of a distance between a rotation axis of a front wheel and a rotation axis of a rear wheel.

Another method of using a HAT bicycle may include at least one of the steps of: providing the driving axis of the hydraulic motor as a pedal axis of the HAT bicycle, providing the driving axis as a rotation axis of a front wheel of the bicycle; providing the driving axis as a rotation axis of a rear wheel of the bicycle; coupling the driving axis with at least one of the pedal axis, the rotation axis of the front wheel, and the rotation axis of the rear wheel with a chain; and coupling the driving axis with at least one of the pedal axis, the rotation axis of the front wheel, and the rotation axis of the rear wheel with at least one gear.

Another method of using a HAT bicycle may include at least one of the steps of: constructing the hydraulic motor or the hydraulic pump to have a weight less than a preset value for Increasing a driving efficiency (e.g., a light-weighting step); constructing the hydraulic motor or the hydraulic pump to have a size (e.g., a length, a height, or a width), a thickness, or an internal or external volume to be less than a preset value to increase a driving efficiency (e.g., a miniaturization step); manipulating each of the hydraulic motor or the hydraulic pump to rotate in a certain range of rpm for discharging the pressurized fluid in a certain discharging volume (e.g., a step of restricting rpm ranges); configuring the hydraulic motor or the hydraulic pump to pressurize fluid under a preset value for increasing a driving efficiency (e.g., a step of driving in low pressure ranges), and the like. The above method may include the step of slowing down or stopping the bicycle by blocking the fluid flow (e.g., a hydraulically braking step).

As defined herein, a “hydraulic pump” means a pump which uses mechanical energy supplied by a user to pressurize fluid contained therein, to increase such fluid pressure, and to discharge the pressurized fluid out of the hydraulic pump in a flow of such fluid. Examples of such hydraulic pumps may include, e.g., a vane pump, a gear pump, a piston pump), a screw pump, and the like. In one example, the vane pump includes multiple vanes which are incorporated Into a rotor, where the rotor rotates along with a driving axis of the vane pump and where the vanes compress and pressurize such fluid while rotating. In another example, a gear pump includes multiple gears which rotate about multiple driving axes and which pressurize the fluid placed in multiple gaps defined between such gears. In another example, a screw pump includes a single or multiple screws which rotate about a single or multiple driving axes and which pressurize the fluid placed in their threaded grooves. In another example, a piston pump includes a single or multiple cylinders containing the fluid and pressurizes the fluid by a single or multiple pistons which reciprocate along the cylinders. More particularly, the piston pump may be a rotary piston pump or a reciprocating piston pump, where the former pressurizes fluid contained in a horizontal or vertical cylinder with a piston reciprocating in a direction of a driving axis of the piston, whereas the latter converts a rotating movement of a driving axis of a piston into a reciprocating movement and pressurizes fluid contained in a cylinder with a piston. In addition, such a piston pump may also include an axial piston pump and a radial piston pump, where a piston moves in a direction parallel with a driving axis in the former, whereas a piston moves in a direction vertical to a driving axis in the latter.

In addition and as further defined herein, a “hydraulic pump” may include a “fixed-volume hydraulic pump” and a “variable-volume hydraulic pump” such that a volume of fluid discharged per a revolution of a driving axis of the hydraulic pump (i.e., a “discharging volume”) is constant in the fixed-volume hydraulic pump but is varying in the variable-volume hydraulic pump.

Therefore, a variable-volume hydraulic pump may include a prior art variable-volume [1] vane pump, [2] gear pump, or [3] piston pump, while a fixed-volume hydraulic pump may include a prior art fixed-volume [1] vane pump, [2] gear pump, [3] piston pump, or [4] screw pump. In addition, a lobe pump, a scroll pump, a progressive cavity pump, a diaphragm pump, or a peristaltic pump may be used as the fixed-volume hydraulic pump, while a lobe pump, a scroll pump, a progressive cavity pump, a diaphragm pump, or a peristaltic pump may be constructed to have a variable discharging volume and, therefore, used as a variable-volume hydraulic pump.

As defined herein, a “hydraulic motor” includes a pump which is of the same type as the above “hydraulic pump,” which operates in the same way as the “hydraulic pump,” but which functions in an opposite way to the “hydraulic pump.” That is, in contrary to the hydraulic pump which converts the mechanical energy into the fluid pressure, the hydraulic motor generates the mechanical energy by converting the fluid pressure into a fluid flow. In this aspect, the hydraulic motor may be classified based on the types of pressurization such as, e.g., a vane motor, a gear motor, a piston motor, or a screw motor. In addition, the hydraulic motor may include a “fixed-volume hydraulic pump” having a constant discharging volume and a “variable-volume hydraulic pump” having a variable discharging volume. Therefore, the variable-volume hydraulic motor may include a variable-volume [1] vane motor, [2] gear motor, or [3] piston motor, while a fixed-volume hydraulic motor may instead include a fixed-volume [1] vane motor, [2] gear motor, [3] piston motor, or [4] screw motor. As is the case with the above, a hydraulic pump, a lobe motor, a scroll motor, a progressive cavity motor, a diaphragm motor, or a peristaltic motor may be used as the fixed-volume hydraulic motor, while a lobe motor, a scroll motor, a progressive cavity motor, a diaphragm motor, or a peristaltic motor may be constructed to have a variable discharging volume and, therefore, used as a variable-volume hydraulic motor.

A “hydraulic pump (or motor)” of this disclosure generally refers to a “positive displacement pump (or motor).” In other words, such a hydraulic pump (or motor) displaces a constant volume of fluid per one revolution of its driving axis, regardless of a magnitude or a change in the mechanical load.

It is noted, however, that such a “hydraulic pump (or motor)” may include not only the positive displacement pump (or motor) but also a “variable-volume pump (or motor)” which refers to a pump (or motor) which can displaces a varying volume of fluid per revolution of its driving axis according to a change in the mechanical load. More particularly, when a HAT bicycle includes a HAT which in turn includes at least one variable-volume hydraulic pump, the HAT may also include at least one positive displacement hydraulic motor or at least one variable-volume hydraulic motor.

Various variable-volume vane pumps (or vane motors) may be constructed or operated as exemplified in various prior art documents such as, e.g., U.S. Pat. Nos. 3,824,045, 4,421,462, and 4,316,706, Korean Pat. Nos. 10-1382073, 10-1177595, and 10-1235988, and the like.

Various variable-volume gear pumps (or gear motors) may be constructed or operated as exemplified in various prior art documents such as, e.g., U.S. Pat. No. 3,847,515 and Korean Pat. No. 10-1449224, while variable-volume piston pumps (or piston motors) may be constructed or operated as exemplified in prior art documents such as, e.g., Korean Pat. No. 10-0429928, Korean Utility Model 20-0467725, and the like.

As used herein, a “frame of a bicycle” or simply a “frame” refers to a backbone of a bicycle, except a handle, a seat, a pedal, a chain gear, a mechanical or hydraulic brake, a front wheel, a rear wheel, and the like.

As used herein, a “mechanical load” refers to a load which is exerted onto a HAT bicycle of this disclosure and which is generally determined by a feature of a road on which a user rides a HAT bicycle, or a slope of such a road and which is also determined by mechanical energy applied by a user or by an electrical motor operating on an electrical battery. Therefore, when other things being equal, the mechanical load increases as a user rides a HAT bicycle uphill than riding downhill, as a user provides more mechanical energy to a HAT bicycle, and the like. In addition, the “mechanical load” may also be affected by an acceleration of a HAT bicycle. Accordingly, when other things being equal, the mechanical load Increases as a user rides a HAT bicycle while increasing its speed (i.e., accelerating) than while decreasing its speed (i.e., decreasing). The “mechanical load” may further be affected by a weight of a user, a cargo loaded on a HAT bicycle or by a total weight of everything loaded on or attached to a frame of the HAT bicycle. Accordingly, when other things being equal, the “mechanical load” Increases when a weight of such things attached to a HAT bicycle Increases than decreases. In other words, the ‘mechanical load’ may be viewed as mechanical energy which is required to move a HAT bicycle along with a user and along with optional cargoes at a desired speed.

It is appreciated throughout this disclosure that a term ‘consist of’ has two different meanings. When the term is used in a claim, it corresponds to a transition phrase for a closed terminology. When the term is used in other parts of this disclosure, the term corresponds to “include” or “to make” such that the term does not mean the closed terminology. In other words, the term “consist of” used in the disclosure except in the claim does not mean the closed terminology.

