Patent ID: 6467368
Filing Date: 2002-10-22
Classification: B62M,Y10T

Abstract:
A hand operated bicycle gear transmission device comprising:a handle bar fixing base for securing the gear transmission device on a handle bar of a bicycle frame, and positioning all component parts of the gear transmission device at respective positions; a cover fixing base adapted for loading a rubber cover and being installed on said handle bar fixing base co-axially with the handle bar of the bicycle thereby the two bases are rotatable with respect to each other; the rubber cover adapted to be rotated by a rider of a bicycle to transmit torque via the rubber cover to the cover fixing base; a positioning plate having a plurality of recessed slots for engaging with a positioning protuberance of the cover fixing base for obtaining a desired speed and positioning effect; the positioning protuberance adapted for engaging with one of the plurality of recessed slots formed on said positioning plate for obtaining a desired speed; two compressible springs being pre-stressed to deform during assembly to reserve a restoring force applied to the positioning plate so as to guarantee a dependable engaging force between said positioning protuberance and one of said indexing recessed slots thereby preventing said positioning protuberance from disengaging from one of said indexing recessed slots; the cover fixing base comprising a circular hole adapted for fixing and confining a steel cable head therein and causing a cable attached to the cable head to move when pulled by the rotation of the cover fixing base; a steel cable guide groove for detaining the steel cable in the cable guide groove so as to control the moving route of said steel cable without derailing during speed change; and a stroke compensating means attached to the gear transmission device for providing compensation of excessive shift of a gear shift lever during speed change for each gear position.