Patent ID: 7651423
Filing Date: 2010-01-26
Classification: B62K,B62M,Y10T

Abstract:
1. A variable speed drive device adapted to be coupled to a variable speed gearshift device of a bicycle via a transmission member to electrically drive the variable speed gearshift device, the variable speed drive device comprising: a case member configured and arranged to be mounted to a frame of the bicycle; a motor drive mechanism mounted on the case member, the motor drive mechanism having a revolving shaft with a first pivot axis that is stationary with respect to the case member; and a linking structure having a retaining portion configured and arranged to retain the transmission member, the linking structure being mounted on the revolving shaft of the motor drive mechanism, and configured and arranged such that a length of a hypothetical arm line measured extending from a center of rotation of the revolving shaft perpendicularly to a longitudinal axis of the transmission member changes depending on a rotational phase of the revolving shaft when the transmission member is attached to the retaining portion, the linking structure further including