Abstract: A derailleur for a bicycle, which is adapted to shift a driving chain to a selected one of two or more sprocket wheels by pushing or pulling a push-pull control wire. The derailleur is provided with at least one arm oscillating independently from a movable member in shifting one of the push-pull wire and an outer cable for the wire. The wire is secured to the arm and a spring is secured to the arm so that when the movable member is, in changing speed, loaded above a predetermined value, the arm is oscillated to prevent the wire from buckling. On the other hand, when the resistance is removed the energy stored in the spring by the oscillation of the arm allows the movable member to shift so that the driving chain may be shifted to a desired speed-changing stage.

Abstract: A four member derailleur is disclosed having a control element which includes a plurality of engageable portions corresponding to the number of speed change stages mounted to one of the four members and a retainer for engaging with or disengaging from the engageable portions to keep a movable member of the four members in a proper position. The derailleur also includes means for moving the retainer in the direction of disengaging from each of the engageable portions so that when the movable member returns, through action of a return spring, the retainer may disengage from each of the engageable portions allowing the return movement of a chain guide.

Abstract: A front derailleur for a bicycle has a chain guide having two opposite guide plates spaced at an interval larger than the width of a driving chain and an outer guide plate of the two guide plates is provided with a chain face which is formed at a position substantially intermediate lengthwise and at an upper portion widthwise of the same and radially outward to a chain sprocket and projects toward an inner guide plate. The chain guide face and the inner surface of the inner guide plate are spaced at an interval slightly larger than the width of the driving chain and smaller than the interval between the two guide plates.

Abstract: A speed changing device is described for a bicycle or other chain driven vehicle comprising a lever at the steering side, a derailleur having a chain guide switching a driving chain to one of several multi-speed sprockets, a control cable comprising an inner wire transmitting the lever action to the derailleur for operating the chain guide and an outer sheath guiding wire, a pull mechanism for stretching the wire, and an adjustment mechanism for offsetting a change of relative effective length between the inner wire and the outer sheath.

Abstract: A derailleur for a bicycle, which comprises a base member, a movable member and two linkage members carrying the movable member therewith in the relation of being swingingly movable with respect to the base member, a control member swinging independently from the movable member, a pair of plates for energy-storing, which sandwich therebetween one of the linkage members and cooperate with the control member through an engageable projection thereof and a positioning and maintaining member provided between the control member and one of the base member, movable member and two linkage members for positioning the driving chain guide cages with respect to any one of a plurality of sprockets whereby the speed change stage can preliminarily be selected when the bicycle is at a standstill or while running when not pedalling.

Abstract: A derailer for a bicycle, comprising a fitting member, a movable member, and a connecting member for movably connecting the movable member with the fitting member, at least one control member swingable independently of the movable member, a spring energized by the swing of the control member, and a positioning device provided between the control member and one of the fitting member, movable member and connecting member and serving to positionally set a chain guide on the movable member with respect to one of a plurality of sprockets, so that the speed-changing stage previously desired may be selected when the pedals stop rotating regardless of whether the bicycle is at a standstill or coasting.