Patent ID: 6623389
Filing Date: 2003-09-23
Classification: B62M,Y10T

Abstract:
Gear shift device for bicycles, comprising:at least one derailleur, having a first body designed to be attached to a bicycle frame, and a second body that can be displaced with respect to the first body to cause selective engagement of a bicycle chain on a number of sprockets to achieve various gear ratios of the device, an electric actuator to cause movement of the second body of the derailleur, electronic control means for governing said electric actuator, manually-operated activating means connected to said electronic control means for causing activation of said electric actuator in order to select a required gear ratio and, means for detecting the position of said second body of the derailleur and for signaling said position to said control means so as to enable the electric actuator to be disabled automatically once the required gear ratio has been reached, wherein said electric actuator is associated directly with said derailleur, and wherein said detection means are comprised of an absolute transducer associated with said derailleur and designed to produce an electric output signal indicative of an absolute position of said second body of the derailleur.