Gear shifting system for derailleur equipped bicycle
First Claim
1. A method for controlling the gear ratio of a bicycle having a plurality of front chainwheels and a plurality of rear sprockets, front and rear derailleurs controlling the position of a bicycle chain on selected ones of said chainwheels and sprockets comprising the steps of:
- generating a first electrical signal corresponding to the velocity of the bicycle;
generating a second electrical signal corresponding to the crank speed of said bicycle;
providing a microcontroller responsive to said first and second electrical signals for calculating the actual gear ratio and comparing it with preset values to see if it is within a first set of limits, if within said first set of limits the microcontroller thereafter determining whether the crank speed is within a second set of limits, the microcontroller generating a third signal if the crank speed is below limits and the bicycle is moving at a speed above a threshold value; and
controlling said front and rear derailleurs in response to said third electrical signal whereby said bicycle chain is downshifted to the next lowest gear.
1 Assignment
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Accused Products
Abstract
A gear shifting system for use on a derailleur equipped bicycle having automatic and manual modes of operation. A microcontroller is mounted to the bicycle frame. Sensors are also mounted to the frame to allow the microcontroller to determine the most efficient gear ratio based on the bicycle velocity and the user pedaling rate in the automatic mode of operation. Servomotors mounted to the bicycle frame are responsive to the outputs to drive the bicycle derailleur and provide the most efficient gear ratio. A control panel mounted to the bicycle handlebars allows the user to select either the automatic or manual operating mode, the latter allowing manual activation of the gear shifters through the microcontroller and servomotors. The microcontroller has at least two input capture functions responsive to bicycle velocity and the cadence, in the automatic mode, and two output compare functions which adjust the derailleurs accordingly.
161 Citations
15 Claims
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1. A method for controlling the gear ratio of a bicycle having a plurality of front chainwheels and a plurality of rear sprockets, front and rear derailleurs controlling the position of a bicycle chain on selected ones of said chainwheels and sprockets comprising the steps of:
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generating a first electrical signal corresponding to the velocity of the bicycle; generating a second electrical signal corresponding to the crank speed of said bicycle; providing a microcontroller responsive to said first and second electrical signals for calculating the actual gear ratio and comparing it with preset values to see if it is within a first set of limits, if within said first set of limits the microcontroller thereafter determining whether the crank speed is within a second set of limits, the microcontroller generating a third signal if the crank speed is below limits and the bicycle is moving at a speed above a threshold value; and controlling said front and rear derailleurs in response to said third electrical signal whereby said bicycle chain is downshifted to the next lowest gear. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Apparatus for controlling the gear ratio of a bicycle having a plurality of front chainwheels and a plurality of rear sprockets, front and rear derailleurs controlling the position of a bicycle chain on selected ones of said chainwheels and sprockets comprising:
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means for generating a first electrical signal corresponding to the velocity of the bicycle; means for generating a second electrical signal corresponding to the crank speed of said bicycle; a microcontroller responsive to said first and second electrical signals for calculating the actual gear ratio and comparing it with preset values to see if it is within a first set of limits, if within said first set of limits the microcontroller then determining whether the crank speed is within limits, the microcontroller generating a third signal if the crank speed is below limits and the bicycle is moving at a speed above a threshold value; and means for controlling said front and rear derailleurs in response to said third electrical control signal whereby said bicycle chain is downshifted to the next lowest gear. - View Dependent Claims (8, 9, 10, 11, 12)
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13. Apparatus for controlling the gear ratio of a bicycle having a plurality of front chainwheels, a plurality of rear sprockets and first and second wheels, first and second pedals, front and rear derailleurs controlling the position of a bicycle chain on selected ones of said chainwheels and sprockets comprising:
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sensor means operatively mounted adjacent said first wheel for generating a first electrical signal corresponding to the velocity of the bicycle; sensor means operatively associated with said first pedal for generating a second electrical signal corresponding to the crank speed of said bicycle; a microcontroller responsive to said first and second electrical signals for calculating the actual gear ratio and comparing it with preset values to see if ti si within a first set of limits, if within said first set of limits the microcontroller thereafter determining whether the crank speed is within a second set of limits and generating a third electrical signal if the crank speed is outside said second set of limits; and means for controlling said front and rear derailleurs in response to said third signal to shift said bicycle chain whereby said cadence is within said second set of limits, said controlling means comprising first and second servomotors. - View Dependent Claims (14, 15)
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Specification