Demand preparation soluble coffee urn
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a soluble coffee urn in which freeze-dried coffee powder and hot water are discharged into a mixing area and then discharged through a spigot into a cup or other receptacle upon actuation of an operating handle with the flow of product into the cup or receptacle being controlled by the handle with the urn being constructed to replace existing conventional roasted coffee urns or coffee urns in which a batch of coffee is brewed or made and retained in a heated condition for an extended period of time during which the coffee is consumed, which results in considerable deterioration in the quality of the coffee. 
     2. Description of the Prior Art 
     Conventional coffee urns using roasted ground coffee to brew a predetermined large quantity of coffee have found wide acceptance in various food serving establishments, such as restaurants, cafeterias, coffee shops, fast food shops, counter-type diners, and the like, and customers frequently serve themselves or observe the coffee being dispensed from the urn into a cup. One of the problems with this conventional procedure is the deterioration in the quality of the brewed coffee as it remains in the coffee urn while being continuously heated for an extended period of time. Frequently, considerable quantities of brewed coffee must be thrown away and a new batch of coffee must be brewed which, at present day roasted coffee prices, results in in considerable loss of revenue for restaurants, and the like. 
     Many food establishments have made efforts to utilize freeze-dried coffee since it costs less as it allows a higher extractive yield from the raw material and greatly reduces losses from over-brewing and also provides a better quality product since each cup is &#34;freshly&#34; brewed. However, considerable customer resistance is encountered when the use of freeze-dried coffee is observed or recognized for various practical and psychological reasons. 
     In some instances, conventional roasted coffee brewing urns have been converted to brew a batch of coffee by using freeze-dried coffee powder. However, the use of such urns results in a relatively large volume of coffee being brewed, for example, three gallons, and the continual heating of this coffee results in deterioration of its quality and taste and still results in considerable wastage if the entire batch is not consumed within a predetermined time period. 
     Also, various types of dispensing machines have been developed for use with freeze-dried coffee or other powdered food products which involve the discharge of a metered quantity of product along with a quantity of water into a mixing chamber, or the like, with the liquid product then being discharged into a container. Such dispensers usually have an appearance distinctive from a conventional roasted coffee urn and do not include multiple product or multiple service facility and usually meter a single serving for each actuation. The following U.S. patents are exemplary of the developments in freeze-dried coffee machines or powdered food product machines. 
     U.S. Pat. No: 3,084,613--Apr. 9, 1963 
     U.S. Pat. No: 3,385,569--May 28, 1968 
     U.S. Pat. No: 3,568,887--Mar. 9, 1971 
     U.S. Pat. No: 3,671,020--June 20, 1972 
     U.S. Pat. No: 4,015,749--Apr. 5, 1977. 
     Arzberger, et al., U.S. Pat. No. 4,015,749, discloses a machine similar to a number of other freeze-dried coffee dispensers in its function, size, design and components and includes product quantity adjustment by the positioning of an apertured sleeve in surrounding relation to an auger and utilizes a metal plug as the heat sink for dehumidification. The mixing chamber requires a standing vortex of water with the food powder dispensed into its center with the single spout dispensing both coffee and water only subjecting the water to cross-contamination. When automatic filling is discontinued, the machine functions are disconnected until the timer completes a cycle and in addition, the hot water storage and recovery has limited capacity and simultaneous multiple dispensing capacity is not available. 
     Krup, U.S. Pat. No. 3,671,020, utilizes a final mixing chamber for sugar and water which involves extensive agitation in order to dispense a cold drink on a per serving basis without capability of continuously dispensing. This device requires two mixing chambers, does not include any adjustment of the product being metered, cannot dispense water only and does not include simultaneous multiple dispensing capacity. 
     Jacobs, U.S. Pat. No. 3,568,887, is a hot chocolate dispenser requiring a whipper assembly and does not include simultaneous, multiple dispensing capacity and utilizes timers to adjust quantity dispensed. 
     Bookout, U.S. Pat. No. 3,385,569, discloses a cold drink dispenser which also requires a whipper assembly and does not provide simultaneous, multiple dispensing capacity. 
     Maxson, U.S. Pat. No. 3,084,613, discloses a structure for preventing foaming which occurs to some degree in combining powdered foods with water with the mixed product being stored in the dispenser and which does not provide simultaneous, multiple dispensing capacity. 
     While dispensing devices for soluble food powders, freeze-dried coffee, and the like, are well-known, such devices have not, for various reasons, replaced conventional roasted coffee urns in restaurants, cafeterias, and other establishments in which coffee is served. While the above-mentioned patents disclose dispensers having various innovative structures involved, they do not satisfy all of the requirements for replacing a conventional roasted coffee urn. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide a demand preparation soluble coffee urn constructed to provide a replacement for a conventional roasted coffee urn providing double-sided service having one or more coffee outlets per side. 
     Another object of the present invention is to provide a soluble coffee urn having a product release device constructed in the form of a spigot which operates a switch rather than a valve as in a conventional roasted coffee urn, but has all of the appearance and functional characteristics of a spigot. 
     A further object of the invention is to provide a soluble coffee urn which includes a mixing chamber which forms a dispensing spigot and which can be removed without mechanical disconnection of components in order to facilitate cleaning. 
     Yet another object of the invention is to provide a soluble coffee urn in accordance with the preceding objects including a unique dehumidification system utilizing two alternative structures to provide constant flow of dry air past the product discharge area to prevent intrusion of moisture. 
     Another object of the invention is to provide a soluble coffee urn including a canister and canister lid structure to provide necessary capacity, filling capabilities and sanitation capabilities with the structure simulative of a conventional roasted coffee urn. 
     Another feature of the present invention is to provide vertical gauges in the form of transparent tubes or rods on the soluble coffee urn to indicate the product being discharged and to simulate &#34;sight glasses&#34; utilized in conventional roasted coffee urns. 
     Still another important feature of the present invention is to provide a soluble coffee urn in accordance with the preceding objects in which a unique interior component layout is provided including a large capacity hot water tank in association with the other components of the urn to reduce service and maintenance problems and enable the soluble coffee urn to replace conventional roasted coffee urns in an effective manner. 
     These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of the demand preparation soluble coffee urn illustrating the association of the components thereof. 
     FIG. 2 is an end elevational view of the construction of FIG. 1. 
     FIG. 3 is a vertical, sectional view taken substantially upon a plane passing along section line 3--3 of FIG. 1 illustrating specific structural details of the urn. 
     FIG. 4 is a fragmental enlarged sectional view illustrating the specific construction of the mixing chamber and related structure. 
     FIG. 5 is a fragmental sectional view of the urn illustrating an alternative construction. 
     FIG. 6 is a fragmental front elevational view of the mixing chamber and control switch actuator. 
     FIG. 7 is a vertical sectional view taken substantially upon a plane passing along section line 7--7 of FIG. 6 illustrating further structural details of the mixing chamber and control switch actuator. 
     FIG. 8 is a side elevational view of another embodiment of the urn with portions broken away. 
     FIG. 9 is a top plan view of FIG. 8. 
     FIG. 10 is a fragmental sectional view passing along section line 10--10 on FIG. 8. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now specifically to FIGS. 1-4, the demand preparation soluble coffee urn of the present invention is designated generally by reference numeral 10 and includes a rectangular housing 12 provided with generally parallel, spaced side walls or panels 14 and 16 interconnected by end walls or panels 18 with the bottom of the housing or cabinet 12 including a bottom wall 20 and the top thereof being provided with a top wall 22, all of which are interconnected in any suitable manner and constructed of conventional sheet metal, such as stainless steel, or the like. The bottom of the housing or cabinet 12 is supported by depending legs 24 engageable with a supporting surface 26 and having laterally extending drain troughs 28 along one or both sides thereof. The soluble coffee urn 10 may be supported in exactly the same location as a conventional roasted coffee urn and the housing or cabinet structure 12 is closely simulative of a conventional urn so that customers observing the urn 10 will recognize it as having the same appearance as a roasted coffee urn. 
     Disposed on the top wall 22 is a pair of lids 30 of generally cylindrical configuration and provided with a central handle 32 in the form of a knob, or the like. The lids 30 are quite similar in appearance to the cover lids normally provided on a conventional roasted coffee urn. The outermost edge of each lid 30 is supported from the top wall 22 by a hinge structure 34 which enable the lid 30 to be swung upwardly to the broken line position illustrated in FIG. 1 with the hinge structure being such that the lid 30 will be retained in its open position until manually closed. 
     Disposed in the housing or cabinet 12 is a hot water tank 35 having a vertical standpipe 36 extending upwardly therefrom in the central portion of the cabinet 12. The tank and standpipe may be covered with insulation 37. The tank 35 includes an inlet pipe 38 extending downwardly from a float chamber 39 having a float valve 40 therein which maintains a predetermined water level 41 in standpipe 36. The float valve 40 is connected with a source of cold water and standpipe 36 includes a vent 42. A suitable thermostatically controlled heater element (not shown) is provided in the tank 35. The standpipe 36 is also provided with a plurality of hot water discharge lines 43 each of which is provided with a solenoid valve 44 incorporated therein to control discharge of hot water to a mixing and discharging assembly generally designated by numeral 46. 
     Supported in each end portion of the housing 12 is a pair of canisters 48 for receiving freeze-dried coffee or other powdered food products with the upper end of the canister 48 extending above the top wall 22 into the interior of the lid 30. The lower surface of the top portion of the lid is provided with a depending closure plug 50 of tapered configuration or frustoconical in configuration and constructed of relatively soft, resilient material, such as plastic, or the like, to form a seal for the upper end of the canister 48. Thus, when the lid is in closed position, both of the canisters 48 will be closed by a plug 50 and when the lid 30 is pivoted to its open position, both of the canisters 48 will be opened thus facilitating the filling of the canisters 48 with freeze-dried coffee, or the like. The lower end of each canister 48 is supported by a suitable supporting bracket structure 52 attached to a supporting partition or deck 54 disposed interiorly of the housing 12. Also, the lower end of the canister 48 is provided with a bottom wall 56 at the lower end of a reduced lower end portion 58. The reduced lower end portion 58 is provided with a laterally extending delivery tube 60 terminating in a closed end but including a depending discharge nozzle 62 communicating with the outer end portion of the tube 60 as illustrated in FIG. 4. A metering auger 64 is disposed transversely of the reduced end portion 58 of the canister 48 and throughout the length of the discharge tube 60 with the end of the auger 64 opposite to that disposed in the discharge tube 60 extending into an adapter 66 having a drive motor 68 connected thereto and connected to the auger 64 to rotate the auger 64 and discharge freeze-dried coffee or other powdered food from the nozzle 62. The auger 64 and its drive motor is subject to continuous operation as long as the motor 68 is energized which will provide a metered quantity of product to the discharge and mixing assembly 46 with energization of the motor 68 also energizing the solenoid valve 44 to open the discharge line 43 to enable hot water to be discharged into the assembly 46 simultaneously with discharge of the powdered food, freeze-dried coffee, or the like, into the assembly 46. 
     The discharge and mixing assembly 46 includes a housing 70 which extends through the wall 14 and terminates in a vertically disposed, downwardly tapering nozzle 72 simulative of a spigot. Disposed within the housing 70 is a mixing assembly generally designated by numeral 74 and including an open topped shallow tray 76 having a generally horizontal bottom portion 78 at its inner end and a downwardly inclined bottom portion 80 at its outer end which is provided with a discharge spout or nozzle 82 concentrically arranged with respect to the vertical nozzle 72 on the housing 70 so that coffee will be dispensed therefrom by gravity. The end of the tray 76 remote from the spout or spigot 82 is connected with the hot water supply line 43 as illustrated in FIG. 4. The top wall of the housing 70 is provided with an opening 84 therein in alignment with the discharge nozzle 62 of the auger receiving tube 60 so that product will be dropped by gravity from the discharge nozzle 62, through the opening 84 onto the bottom 78 of the tray 76 with the water and soluble coffee or other powdered product being mixed as the water flows along the surface of the bottom portions 78 and 80 of the tray 76 for discharge from the spout 82. 
     In order to operate the motor 68 and the valve 44, a switch 86 is provided interiorly of the wall 14 with an actuating plunger 88 depending through the top wall of the housing 70 into engagement with one end of the pivotally mounted switch actuating lever 90 which has a central portion thereof pivoted to the opposite walls of the housing 70 by a transverse pivot pin 92, or the like. The outer end of the actuator or lever 90 is connected to a pin 94 which is slidably mounted through a removable cap 96 on a screw threaded portion 98 of the top wall of the housing 70 and provided with lugs 100 at its upper end pivotally supporting an operating handle 102 for pivotal movement about a pivot pin 104. A compression coil spring 106 biases the pin 94 downwardly and the bottom end edge of the handle 102 includes a rounded cam portion 108 and a flattened cam portion 110 so arranged that when the handle 102 is pulled outwardly, the switch 86 will be actuated as long as pressure is exerted to pull the handle 102 outwardly. When the handle 102 is pushed inwardly, the flat surface 110 engaging the surface of the cap 90 will retain the switch 86 in operative position for continuous discharge of product from the spout 82. 
     Discharge of hot water into the tray 76 adjacent the nozzle 62 for the powdered product could result in steam vapor causing moisture penetration into the powdered product and caking or clogging of the nozzle 62 or tube 60. In order to preclude this possibility, the nozzle 62 is spaced slightly above the top of the housing 70 and the aperture 84 in the housing 70 is larger than the nozzle 62 thereby providing an air passageway communicating the interior of the housing 12 with the interior of the housing 70 above the tray 76. A vertical, enlarged vent pipe 112 extends from the top wall of the housing 70 adjacent the aperture 84 up through the top wall 22 as illustrated in FIG. 4 with a heater 114 being disposed in the vent pipe 112 which is continuously operated. Optionally, the heater 114 may be cycled in any suitable manner. This arrangement prevents moisture intrusion by maintenance of a constant flow of unheated ambient air across the product delivery aperture as indicated by the air flow arrows in FIG. 4. The heater 114 creates air movement rather than directly warming the aperture and its immediate environs. This precludes the loss of volatile aromatics which occurs when coffee and other food powders are in contact with elevated temperatures for extended periods. 
     The flue or vent pipe 112 containing the heater 114 which is supported in spaced relation to the inner periphery thereof produces a low pressure chamber within itself and the mixing area. The air flow caused by the heater lowers the pressure within this area rather than raising it in the rest of the cabinet and the specific dimensional characteristics, temperatures and vent pipe or flue construction may be varied as long as the upward flow of heated air and humid air causes inflow of cool and dryer air around the discharge nozzle 62 so that the powdered material in the canister will not absorb vapor from the hot water as it mixes with the powdered food product discharged into the tray and the powdered material will not lose volatile aromatics as it is waiting to be dispensed from the canister thereby retaining maximum flavor characteristics of the product. 
     Each of the discharge and mixing assemblies has an identification and indicator gauge associated therewith generally designated by 116 which includes a plastic rod or thick walled plastic tube 118 filled with either water or a coffee colored liquid or colored in any manner with the two ends of the rod or tube being supported by opposed brackets 120 having facing sockets 122 therein. It is also possible for the gauges to be labelled by using appropriate indicia on the rod or tube or on a label applied thereto. 
     FIGS. 5-7 disclose alternative structures for providing the same functions as the specific structural features disclosed in FIGS. 1-4. In this embodiment, the housing of the urn is generally designated by numeral 130 and is similar in construction to the housing 12 in FIGS. 1-4 with the dispenser normally being placed on a special stand having a built-in drain. The canister 134, closure lid 136, closure plug 138 thereon, discharge tube 140 having the auger 142 therein and the discharge nozzle 144 are substantially the same as the corresponding elements disclosed in FIGS. 1-4. 
     The discharge and mixing assembly 146 includes a housing 148 supported through the front wall 150 and includes a removable lid 152. Disposed within the housing 148 is an inclined tray 154 having a discharge spout 156 at its lower end and having its other end connected to a hot water inlet pipe 158. The lid 152 is provided with an opening 160 in alignment with but spaced slightly below the discharge nozzle 144 as illustrated in FIG. 4 so that powdered material discharged into the tray 154 will be mixed with water entering the tray from the hot water pipe 158 so that a mixed product will be discharged from the spout 156. The housing 148 also includes a vertically disposed member 162 at the outer end thereof which simulates a spigot and is disposed in concentric spaced relation to the spout 156 so that cool dry air can enter the opening 160 pass around the tray and be discharged between the spout 156 and the vertical member 162 as illustrated in FIG. 7 so that steam vapor will not contact the nozzle 144 or associated portions of the tube 140 and auger 142 to preclude moisture intrusion and prevent elevated temperatures in the structural components and the powder product engaged therewith. 
     In this embodiment, a generally U-shaped actuator or lever 164 is pivotally attached to the opposite sides of the housing by pivot pins 166 and the other end of the U-shaped lever is provided with a vertically enlarged portion 168 having a push plate 170 across the top end thereof to provide an area for depressing the outer end of the lever 164. The inner end of the lever 164 is engaged with the actuating plunger 172 of a switch 174 which functions to drive the auger and open the solenoid valve in the hot water line 158. 
     To provide for air flow downwardly through the opening 160, the housing 130 is provided with a screened air inlet 176 adjacent the upper end thereof having a fan 178 therein with a motor 180 driving the fan to move air from the exterior of the housing or cabinet 130 into the interior thereof, thereby providing a positive pressure in the housing. At the lower end of the housing 130, an opening defined by a tubular member 182 is provided and a closure plate 184 forms a closure for the inner end of the tubular member 182 which is inclined so that the pivot axis 186 for the closure plate is such that the closure plate 184 will normally hang vertically in spaced relation to the inclined inner edge of the tubular member 182 as illustrated by the broken line position in FIG. 5. The end of the closure plate 184 which extends above the pivot axis 186, designated by numeral 188, engages a pivotal actuator 190 mounted on a switch 192 in engagement with the operating plunger 194 therefor so that the switch 192 is, in effect, a pressure sensitive switch so that when there is a positive pressure in the housing 130, the pressure plate 184 will be closed and the pressure switch 192 will enable operation of the solenoid valve in the hot water line and the auger when the push plate 170 is depressed and the switch 174 actuated. In the event that the fan 178 is not being driven by the fan motor 180 and the pressure in the housing 130 drops to ambient pressure, the closure plate 184 will move to its vertical position due to gravity, thus enabling the operating lever 190 to pivot and actuate the plunger 194 so that the circuit to the hot water valve will be broken. Even though the differential pressure between the interior of the housing 130 and the pressure exterior thereof is only slight due to the fan 178, it is clearly sufficient to provide a constant flow of dry air past the critical product discharge area, thus preventing the intrusion of moisture and thereby precluding moisture contamination of the highly hygroscopic food powders. 
     In this construction, a closure door or panel 196 is provided in the front wall 150 of the cabinet with a supporting hinge 198 and latch structure 200 being provided therefor in order to provide access into the interior of the cabinet or housing for repair, replacement, or the like. A similar access panel may be provided in the rear of the cabinet. The pressure switch 192, in addition to deactivating the machine because of fan failure, will also suspend machine operation when either access panel is open or removed thereby protecting against caking problems resulting from unauthorized entry into the dispenser or accidental operation when servicing. A suitable microswitch positioned to be controlled by the position of each access panel could also be used to prevent caking problems. 
     In this arrangement, the outer end of the tube 140 having the nozzle 144 thereon is constructed so that the nozzle is in the form of a sleeve 145 which enables it to be rotated to the broken line position illustrated in FIG. 6, so that the lid 152 may be removed from the housing 148 to provide access to the tray and associated structure for ease of cleaning and the like. 
     FIGS. 8-10 illustrate another embodiment of the urn 202 which includes a large hot water tank 204 located below the canisters and the discharge and mixing assemblies and located below deck 205 and acts as a support for it and insulation therebetween. The tank 204 may be of a size to receive approximately ten gallons of water and is communicated with a water supply in a manner similar to that shown in FIG. 3. Communicated with the center of the tank 204 is a vertical stand pipe or extension 206 which is centrally disposed between end pairs of canisters 208. Water discharge lines 210 and control valves 212 are disposed closely adjacent the stand pipe or extension 206 so that the hot water tank 204 and the extension 206 will form an effective heat sink to maintain the discharge pipes 210 and control valves 212 at an elevated temperature. A cover 214 is positioned in enclosing relation to the valves 212 and a portion of the discharge lines 210 to retain the heat from the heat sink in association with these components. The canisters 208 and the hot water supply lines 210 are connected with discharge and mixing assemblies 216 associated with a housing 218 which has closure lids 219 for the canisters 208 in a manner similar to the structure disclosed in the other embodiments of the invention. As illustrated in FIG. 9, the two center assemblies 216 are communicated directly with the tank extension 206 and thus will discharge only hot water when valve 212 is actuated. 
     To provide access to the interior of the housing 218, side panels 220 may be vertically slidably removed from the top edge of the housing with the lower edge thereof being provided with notches 221 receiving the discharge and mixing assemblies 216 with the indicator gauges mounted on the panel 220, if desired. Also, the tank 204 is supported by suitable supporting legs 222 and a bottom panel 224 extending beyond the tank and provided with a removable panel 226 to enable access to the heater elements 228, thermostatic control, supply valve or other structural components normally concealed by the panel 226. In addition to spatial, structural and maintenance benefits of this arrangement, the direct physical connection to the stand pipe provides the best possible thermal conduction between it and the valves and the discharge lines, so that these components will not absorb substantial heat as the powdered product and water are metered, mixed and dispensed, which can result in a low temperature of the finished product. By eliminating the customary manifold and physically joining each valve to the standpipe and due to its vertical configuration, full flow will be provided through all valves without any pressure or flow fluctuations regardless of the number of valves which may be simultaneously opened. The float valve to control the filling of the water tank may be located in any desired position above the service deck and will fill the tank from the bottom so that the float valve chamber will be filled with cool or cold water which reduces mineral build-up, corrosion and rusting of the float valve components. 
     In each instance, suitable heating elements, controls therefor and controls for maintaining the water supply in the tank are utilized and may be of various conventional components. Also, sanitation and health requirements of various jurisdictions may be easily complied with along with regulations relating to plumbing and electrical installations. 
     The soluble coffee urns provide a mixed coffee product which not only is closely simulative of the brewed coffee from roasted ground coffee but also is dispensed from an apparatus which is quite simulative of a conventional roasted coffee urn. In addition, the mixing of the freeze-dried coffee and water immediately before discharge enables a relatively high water temperature to be used so that the coffee will be quite hot which is significant when feeding in various institutions, such as hospitals, and the like, where substantial delay may be encountered in delivering the coffee to the actual consumer. 
     The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.