Patent ID: 6220111
Filing Date: 2001-04-24
Classification: B62M,G05G,Y10T

Abstract:
A bicycle speed changing device comprising a base having a pivotal column mounted thereon such that said pivotal column is sequentially fitted over by a wire wheel, a ratchet gear, a check plate, a rotary plate, a reverse lever, and a forward lever;wherein said base is provided therein with a position-confining portion;wherein said wire wheel is provided with a locating member for a step-by-step engagement with said position-confining portion of said base and is further provided with a wire head slot;wherein said ratchet gear is linked with said wire wheel and is provided with a plurality of forward teeth and reverse teeth;wherein said check plate is provided with a first retaining portion and a second retaining portion and is fastened with a predetermined position of said base;wherein said rotary plate is provided with a stop portion, a reverse pawl for retaining said reverse teeth of said ratchet gear, and an elastic member for providing said rotary plate with an elastic force enabling said rotary plate to turn to press against said second retaining portion of said check plate;wherein said reverse lever is provided with a rotation stopping portion for retaining said stop portion of said rotary plate, and a push portion for pushing said reverse pawl of rotary plate;wherein said forward lever is provided with a forward pawl for retaining said forward teeth of said ratchet gear, and an elastic member for actuating said forward push rod to turn to press against said first retaining portion of said check plate;said reverse lever and said forward push lever rod being located respectively at a predetermined position while not in action whereby said forward lever is actuated by hand of a bicyclist to cause said forward pawl to turn said ratchet gear, thereby actuating said wire wheel to turn to pull a guide wire to attain a forward speed-changing operation whereby said reverse lever is actuated by hand of the bicyclist to cause said push portion to push said reverse pawl to locate at said reverse teeth of said ratchet gear, thereby causing said ratchet gear to turn, and actuating said wire wheel to turn to pull said guide wire to attain a reverse speed-changing operation.