1. Field of the Invention
This invention generally relates to a bicycle transmission. More specifically, the present invention relates controlling a motor of a bicycle component used in a bicycle transmission.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One part of the bicycle that has been extensively redesigned is the transmission or drive train of the bicycle. Specifically, manufacturers of bicycle components have been continually improving shifting performance of the various shifting components such as the shifter, the shift cable, the derailleur, the chain and the sprocket.
Recently, bicycles have been provided with an electronic drive train for smoother shifting. These electronic drive trains include a rear multi-stage sprocket assembly with a motorized rear derailleur and a front multi-stage sprocket assembly with a motorized front derailleur. These derailleurs are electronically operated by a cycle computer for automatically and/or manually shifting of the derailleurs.
A typical bicycle transmission is operated by a shift operating wire connected between the transmission and a manually operated shift operating device mounted on the handlebar. The rider operates the shift operating device to selectively pull or release the shift operating wire which, in turn, operates the transmission in the desired manner.
One of the goals of bicycle transmission design is to make the transmission easy to operate with a minimum amount of effort. This involves minimizing the force needed to operate the shift operating device as well as minimizing the amount of unnecessary movement of the shift operating device. In the case of bicycle transmissions such as derailleurs which are used to shift a chain from one sprocket and move it to another can be quite large, especially when the destination sprocket is substantially larger than the originating sprocket and the rider is exerting substantial pedaling force on the chain. The necessary operating force can be reduced by operating the shift operating device when only a small pedaling force is being applied to the chain, but that requires the rider to consciously alter his or her pedaling technique and/or consciously operate the shift operating device only when a small pedaling force is being applied to the chain. That can be very distracting, especially in a racing environment. Also, the actuation of ratio of some derailleurs may be somewhat large. Consequently, the shift operating wire must move a substantial distance to fully move the chain from one sprocket to another, thus requiring the rider to move the shift operating device by a correspondingly large amount.
In view of the above, there exists a need for a bicycle transmission which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
One object of the present invention is to provide a simplified method of controlling a motor of a bicycle component.
Another object of the present invention is to provide a power assist for a front derailleur.
The foregoing objects can basically be attained by providing a method of controlling a motor of a bicycle assembly, comprising the steps of supplying current to the motor to move a bicycle component between a first position and a second position; monitoring current flow to the motor during movement of the bicycle component; and stopping flow of current to the motor upon detection of an overcurrent to the motor due to the bicycle component reaches one of the first and second positions after being driven from the other of the first and second positions.
The foregoing objects can also be attained by providing a bicycle assembly, comprising a motor having an overcurrent detecting circuit operatively coupled to a power input line of the motor to interrupt current flow to the motor upon detection of an overcurrent; and a bicycle component operatively coupled to the motor to move the bicycle component between a first position and a second position such that the overcurrent occurs in the motor when the bicycle component reaches one of the first and second positions after being driven from the other of the first and second positions.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.