Patent DE-602005001339-C5 (DE)
Title: Steuereinrichtung für einen Fahrradkettenumwerfer und Verfahren zur Steuerung des Vorderradkettenumwerfer
Inventor: ICHIDA TADASHI
IPC: B62M25/08
Filed: 2005-04-05
Granted: 2019-10-10
Abstract: A bicycle transmission control apparatus for controlling the operation of an electrically controlled front derailleur and an electrically controlled rear derailleur, wherein the apparatus comprises:
 a control unit that provides a signal to operate the electrically controlled front derailleur by a gear shift distance from an origin sprocket to a destination sprocket and a signal to operate the electrically controlled rear derailleur by a gear shift distance from an origin sprocket to a destination sprocket,
 wherein the control unit receives a condition signal that indicates a condition resulting from gear shift operation of at least one of the electrically controlled front derailleur and the electrically controlled rear derailleur;
 an adjustment controller that moves the electrically controlled front derailleur by an adjustment distance less than the gear shift distance in response to the condition signal
 comprising a first position signal indicating a position of the electrically controlled front derailleur and a second position signal indicating a position of the electrically controlled rear derailleur, wherein the adjustment controller moves the electrically controlled front derailleur by the adjustment distance in response to a combination of the first position signal and the second position signal, wherein the adjustment controller moves the electrically controlled front derailleur by the adjustment distance
 - when the first position signal indicates the electrically controlled front derailleur is located at a laterally innermost sprocket associated with the electrically controlled front derailleur and the second position signal indicates the electrically controlled rear derailleur is located at one of the M outermost sprockets associated with the electrically controlled rear derailleur wherein M is an integer and M is less than or equal to three;
 - or when the first position signal indicates the electrically controlled front derailleur is located at a laterally outermost sprocket associated with the electrically controlled front derailleur and the second position signal indicates the electrically controlled rear derailleur is located at one of the M innermost sprockets associated with the electrically controlled rear derailleur, wherein M is an integer and M is less than or equal to three; and
 a return controller that selectively returns the electrically controlled front derailleur after shift operation of the electrically controlled rear derailleur to a position it had prior to movement by the adjustment controller, and wherein the return controller only returns the electrically controlled front derailleur following shift operation of the electrically controlled rear derailleur to the position it had prior to movement by the adjustment controller
 - either after an upshift operation of the electrically controlled rear derailleur when the first position signal indicates the electrically controlled front derailleur is located at a laterally innermost sprocket associated with the electrically controlled front derailleur, and the second position signal indicates the electrically controlled rear derailleur is located at the (M+1) th  outermost sprocket associated with the electrically controlled rear derailleur;
 - or when after a downshift operation of the electrically controlled rear derailleur the first position signal indicates the electrically controlled front derailleur is located at a laterally outermost sprocket associated with the electrically controlled front derailleur and the second position signal indicates the electrically controlled rear derailleur is located at the (M+1) th  innermost sprocket associated with the electrically controlled rear derailleur.