Abstract: The transmission comprises two sprockets which are mounted on respective arm members which are cantilever-wise mounted on a round cross-section rod housed in a sleeve member and resiliently counter-biassed by one or more coil springs, the sleeve member being coupled to the base of an articulated parallelogram system so as to be displaced by a pair of small cables forming a positive driving system adapted to be actuated by a small lever.

Abstract: The device adjusts the length of a control cable which is interposed between an operating machine, such as a derailleur, and a control device therefor. The device is provided with a temporary stop mechanism for temporarily, stepwise stopping rotation of an adjuster. The device also includes a clicking mechanism by which an operator senses a clicking action when rotating the adjuster. The stop interval for the clicking mechanism is set to be larger than the minimum incremented stroke of the control cable required for adjustment thereof one increment at a time.

Abstract: A derailleur for a bicycle is provided which includes a deformable linkage mechanism and is adapted to deform the linkage mechanism through a control wire for changing the bicycle speed. A saver arm is supported to the linkage mechanism to be forwardly and backwardly swingably. The control wire is fixed to the saver arm, and a saver spring is interposed between the saver arm and the linkage machanism, the saver arm includes a spring urging portion which deflects the saver spring when the saver arm swings forwardly and backwardly and applies to the saver arm a spring reaction to restore a saver arm in the direction opposite to the swinging direction thereof.

Abstract: A rear derailleur for bicycle gears comprises an upper body which can be fixed to the bicycle frame and a lower body carrying chain transmission member and being movable relative to the upper body to bring the chain into selective engagement with a series of sprockets carried by the hub of the rear wheel of the bicycle. The lower body is connected by an articulated parallelogram joint to an intermediate connecting element which is in turn mounted for sliding on guide member carried by the upper body. Connecting rods are provided for univocally correlating the movements of the intermediate element relative to the upper body with the movements of the lower body relative to the intermediate element. In this way, the resulting movement of the lower body relative to the upper body has both a component along the axis of the hub of the rear wheel of the bicycle, and a component radial to that axis.

Abstract: A bicycle deraileur comprising a parallelogrammic linkage mechanism including a base member, a first link pivotally connected at one end thereof to the base member by a first pin, a second link pivotally connected at one end thereof to the base member by a second pin, and a movable member pivotally connected to the other ends of the first and second links by third and fourth pins respectively; a chain guide mechanism carried by the movable member; an operating member pivotally mounted on the firs pin for operation by a cable and provided with a pin; a torsion spring arranged on the first pin to engage with the operating member and the first link, the spring elastically urging the operating member to counteract a tension applied to the cable; and a restraining link pivotally connected at one end to the fourth pin and having a slot extending from the other end toward the fourth pin and slidably receiving the pin of the operating member.

Abstract: A front derailleur for a bicycle which includes a linkage mechanism which is formed of a fixing member, a chain guide and a pair of linkage members. Four pivot shafts connect the linkage members with the fixing member and the chain guide and have axes which are slanted forwardly from a perpendicular plane through a center line between the guide plates the fore ends of the pivot shafts are positioned farther than their rear ends from the chain guide. When the linkage mechanism is deformed, the chain guide is moved axially of the multistage front gears and obliguely longitudinally of the bicycle, thereby improving the speed change characteristics and speed control efficiency of the derailleur.

Abstract: A derailleur is provided which includes a linkage mechanism including a fixing member, a chain guide for guiding the driving chain relative to a gear assembly, and a linkage device. The chain guide has an inner guide plate and an outer guide plate which are (1) generally parallel to one another, (2) adapted to be oriented perpendicular to the axis of the gear assembly and (3) extend in a longitudinal dimension which is adapted to be oriented longitudinally of the bicycle when the derailluer is mounted on the bicycle. The linkage device supports the chain guide to the fixing member so that the chain guide is movable axially with respect to the gear assembly. The linkage device has one end pivotably supported to the fixing member by a first pivot shaft and another end pivotably supported to the chain guide by a second pivot shaft.

Abstract: A front derailleur for a bicycle which is provided with a linkage mechanism formed of a fixing member, first and second linkage members, and a movable member. The first and second linkage members are pivotally supported through first and second pivot shafts to the fixing member. The first and second pivot shafts are each fixed at one axial end thereof to the fixing member and, pivotally support at intermediate thereof the linkage members respectively. The first and second pivot shafts are connected at their other axial ends by a connector, so that a load due to an operating force to operate the linkage mechanism is dispersed to the first and second pivot shafts, thereby enabling the front derailleur to be miniaturized and inexpensive to produce.

Abstract: A derailleur for a bicycle comprises a fixing member; a transformable linkage mechanism comprising a base member, two linkage members and a movable member; and a chain guide having a guide pulley and a tension pulley. The linkage mechanism is supported swingably to the fixing member in the relation that the guide pulley reciprocates away from or toward the axis of the sprocket assembly. The derailleur is provided between the chain guide and the movable member with a first spring, between the fixing member and the linkage mechanism with a second spring for biasing the guide pulley away from the axis of sprocket assembly, and with a forcibly moving mechanism which moves the chain guide axially of the sprocket assembly and also radially thereof in a plane perpendicular to the axis of the sprocket assembly.

Abstract: The derailleur includes a linkage mechanism comprising a fixing member fixed to the bicycle frame, a pair of linkage members pivoted to the fixing member, and a movable member carrying a chain guide and pivoted to the linkage members. The linkage mechanism is provided with a displacement structure which elastically biases the linkage mechanism axially of a multistage sprocket assembly when subjected to a force or pressure greater than a normal resistance against speed change, thereby preventing the fixing member and bicycle frame from being plastically deformed as a result of a sudden forceful impact, such as in a collision, hitting a foreign object of if the bicycle falls down.

Abstract: A bicycle derailleur which includes a linkage mechanism formed of a base member, an inner linkage member, an outer linkage member, and a movable member carrying a chain guide. The derailleur also includes a connecting assembly formed of a pair of connecting pins for respectively pivotably supporting one end of each of the inner and outer linkage members to the base member and a pair of connecting pins for respectively pivotably supporting the movable member to the other end of each of the inner and outer linkage members. The connecting pins are oriented obliquely with respect to a predetermined plane perpendicular to the axis of the sprocket assembly. The chain guide, responsive to deformation of the linkage mechanism, moves axially and radially of the sprocket assembly.

Abstract: A control device for controlling, preselecting and indexing rear derailleur gear changes on bicycles and similar vehicles. An operating lever is shaped and designed to work together with the control device for adjusting and indexing. The lever may be started from a neutral position to effect a tensioning or slackening of the cable on each reversal of the direction of a pivoting of the lever. The cable can be acted on to move the chair guide transversely for changing or selecting one or more gears, depending on whether or not there is a pedalling action.

Abstract: An easy to operate control means for shifting gears on dual shift bicycles is described. The control means is constructed so that the front and rear derailleurs of a dual shift bicycle are controlled together to shift to any selected gear from any engaged gear with a single operator action. The design permits the operator to preselect the new gear to be used while continuously pedaling in the present gear, with the actual gear change being made at the operator's discretion. The design also facilitates a rapid series of down shifts without requiring intervening gear selections.

Abstract: In a gearshift for bicycles--of the type controlled by a driving cable and with articulated parallelogram, comprising two connecting rods which connect an upper body, pivoted to the end of the rear fork of the bicycle frame, to a lower body carrying an oscillating rocker arm guiding the transmission chain--means are provided in the form of a rod having its end linked by means of ball hinges to the lower body of the gearshift and, respectively, to a fixed point on the rear fork.

Abstract: The derailleur is provided with a base member; a linkage mechanism including a support member, a pair of linkage members, and a movable member; and a chain guide having a guide sprocket and a tension sprocket. The support member is supported swingably relative to the base member through a first horizontal shaft, and the chain guide is supported swingably relative to the movable member through a second horizontal shaft. Also, first and second springs are provided between the base member and the linkage mechanism, and the movable member and the chain guide. The first and second springs balance with each other to set the position of the guide sprocket with respect to a selected particular rear chain gear. The spring force of at least one of the first and second springs is changed with respect to the other by the swinging motion of at least one of the linkage mechanism and the chain guide in excess of a predetermined angle, thereby yielding an optimum distance between the guide sprocket and the rear chain gear.

Abstract: The invention relates to a gear-change device for derailleurs or gear-change hubs in which by enlargement of at least one of the provided detents in the circumferential direction and by arrangement of a spring which biases the change lever in the one direction an easy adjustability is provided by an adjusting screw. Furthermore the exchanging of detent discs for easy adaptation to different gear ratio numbers is easily possible. The assembly of the gear changer is easy to effect in as much as two component groups can be prefitted independently of one another. A shift-over device for one direction, as utilized advantageously especially in derailleurs, can easily be integrated.

Abstract: A derailleur for a bicycle having a derailleur body having a base member, a movable member having a chain guide, and a support means for supporting the movable member movably axially of a multistage sprocket assembly with respect to the base member; and a control cable for movably controlling the movable member, whereby an amount of movement of the chain guide in the axial direction of a multistage sprocket assembly is made adjustable with respect to a constant control amount of the control cable.

Abstract: A rear derailleur for a bicycle having a linkage mechanism supported swingably to a fixing member through a first horizontal shaft, a first spring interposed between the linkage mechanism and the fixing member, and a second spring interposed between a movable member at the linkage mechanism and a chain guide, so that the first and second springs balance with each other to allow the linkage mechanism and chain guide to swing, thereby controlling a guide pulley at the chain guide in position with respect to each sprocket at the multistage sprocket assembly. Hence, even when the position to support an operating wire for the linkage mechanism during the swinging motion thereof varies to vary the position of the guide pulley with respect to the multistage sprocket assembly, an interval between the chain and the urging surface therefor is held constant.

Abstract: The subject matter of the invention refers to the technical area of vehicles in general, of cycles and similar vehicles and their fittings and accessories.A rod (4) or equivalent means is mounted in the lower bracket (1) perpendicularly to the cylindrical recess axis (1b) and secant with the peripheral part of said recess, to assume the dual function of holding the bolt (2) with respect to the bracket (1) and end stopping the rotation of the tensioning arm (D) integral with the bolt (2) with respect to the bracket (1) because of the suitable arrangement of a bearing surface (2d) of the bolt which is in the plane and opposite the rod (4); an elastic means (5) for retensioning the tensioning arm being mounted inside the bracket and suitably connected to the bolt on the one hand and to said bracket on the other hand.

Abstract: A derailleur for a bicycle is provided with a base member, a movable member movable axially of a multistage sprocket assembly, a linkage member for moving the movable member axially of the multistage sprocket assembly, a guide mechanism supported to the movable member and guiding a driving chain from one sprocket to another at the multistage sprocket assembly, and a coiled return spring. At an intermediate portion of the linkage member there is a provided a support shaft for the spring, with the support shaft supporting the coiled portion of the spring. A first end portion of the spring is retained to the linkage member carrying the support shaft, and a second end portion of the spring is movably engaged with a member movable relative to the linkage member, thereby reducing the amount of deflection of the spring for a given amount of movement of the movable member.

Abstract: A cycle accessory, for example a double lever 2, 3 for controlling a derailleur, is carried by a support 4 defining a fixing tab 11 received and wedged in a cavity of complementary shape which may be defined by a part 1 of the frame and a bridge member 14 brazed on the frame. The arrangement is such that, when a force is exerted on the accessory in the course of use, this force tends to increase the wedging between the fixing tab 11 and the cavity. Applicable to any accessory for a cycle.

Abstract: A rear bicycle derailleur is provided which includes (1) a chain guide formed of a guide pulley, a tension pulley and first and second plates supporting the guide and tension pulleys, and (2) a derailleur body having a movable member supporting the chain guide and support means supporting the movable member to be movable axially of the multistage sprocket assembly. The first plate includes a first restrainer at a side of the first plate adjacent the derailleur body, with the first restrainer being positioned radially outwardly relative to the guide pulley at a location outside a first predetermined chain movement path along which the chain travels from a high speed sprocket of the multistage sprocket assembly to the tension pulley through the guide pulley when the multistage sprocket assembly rotates in reverse. The first restrainer prevents the chain from moving away from the first chain movement path when the multistage sprocket assembly rotates in reverse.

Abstract: A bicycle derailleur which includes a linkage mechanism formed of a base member, two linkage members and a movable member carrying a chain guide. A swingable member is pivotally supported to one of two opposite members of the linkage mechanism. A return spring is supported to the other of these two opposite members and a first leg of the return spring is retained to the swingable member, while a second leg thereof is retained to the other of the aforesaid two opposite members of the linkage mechanism. A control wire is pulled to move the movable member in a forward direction with respect to the base member and the return spring restores the movable member to a rest position, thereby changing the bicycle speed. A variation in an angle of torsion of the spring is reduced with respect to a variation in the forward stroke of the movable member, whereby operating forces at the top gear side and the low gear side of the multistage gear assembly are substantially equalized to each other.

Abstract: An easy to operate control means for shifting gears on dual shift bicycles is described. The control means is constructed so that the front and rear derailleurs of a dual shift bicycle are controlled together to shift to any selected gear from any engaged gear with a single operator action. The design permits the operator to preselect the new gear to be used while continuously pedaling in the present gear, with the actual gear change being made at the operator's discretion. The design also facilitates a rapid series of down shifts without requiring intervening gear selections.

Abstract: A bicycle derailleur is provided which has a pair of linkage members interposed between a base and a movable member. At least one of the linkage members is connected to a least one of the base member and the movable member such that one of (i) the at least one linkage member and (ii) the aforesaid at least one of the base member and the movable member comprises an insertion region having a pair of mounting walls and the other of (i) the at least one linkage member and (ii) the aforesaid at least one of the base member and the movable member comprises an insertion portion inserted between the mounting walls. A link pin is disposed between the mounting walls and passes through the insertion portion. One of (i) both the mounting walls and (ii) opposite surfaces of the insertion portion opposite to the mounting walls includes an annular recess surrounding the link pin. A sealing member is disposed in each annular recess to prevent water, mud, and debris from entering into a space surrounding the link pin.

Abstract: A bicycle derailleur includes a linkage mechanism formed of a base member, a pair of linkage members, and a movable member having a chain guide. The derailleur also includes a fixture for a control wire to operate the linkage members; and a holder for an outer sheath guiding the control wire. The derailleur is provided with a support member supporting the holder and a guide member which is fixed to the support member at the side thereof as which the control wire is drawn out with respect to the position where the holder is supported. The guide is formed of a material having high wear resistance and a low coefficient of friction. The guide member includes a guide bore so that the wire extending between the exit of the holder and the fixture is adapted to come into contact with the inner surface of the guide bore.

Abstract: A front derailleur for a bicycle includes a chain guide and a moving member for moving the chain guide axially of a multistage front chain gear assembly so that a control wire is operated to switch a driving chain guided by the chain guide from one front chain gear to another. A swinging member has one end which includes a support for supporting the control wire or an outer sheath therefor. The swinging member is pivoted at an intermediate portion thereof to the moving device. An adjusting mechanism is located between the other end of the swinging member and the moving member to adjust the position of the swinging member with respect to the moving member and to adjust the position of the chain guide with respect to each front chain gear.

Abstract: A derailleur for a bicycle comprises; a fixing member; a transformable linkage mechanism comprising a base member, two linkage members and a movable member; and a chain guide having a guide pulley and a tension pulley. The linkage mechanism is supported swingably to the fixing member in the relation that the guide pulley reciprocates away from or toward the axis of the sprocket assembly. The derailleur is provided between the chain guide and the movable member with a first spring, between the fixing member and the linkage mechanism with a second spring for biasing the guide pulley away from the axis of sprocket assembly, and with a forcibly moving mechanism which moves the chain guide axially of the sprocket assembly and also radially thereof in a plane perpendicular to the axis of the sprocket assembly.

Abstract: A three-stage speed change front derailleur which shifts a driving chain to one of three front chain gears of different diameter to thereby change the speed includes a linkage mechanism comprising a fixing member, a pair of linkage members and a movable member provided with an inner guide plate and an outer guide plate, the movable member pivotally supporting a shift plate which is positioned below the inner guide plate, and which serves to shift the chain from a smaller diameter chain gear to a middle diameter chain gear, and is pivoted to the movable member in relation of being movable away from a larger diameter chain gear.

Abstract: An automatic shifter for a derailleur is disclosed which includes a pivot arm secured to the frame of the bicycle in stationary relationship, a shifter arm pivotally secured to the pivot arm in a manner to rotatively move relative to the frame, a follower attached to the shifter arm in rotative engagement, an operating spring biasing between the pivot arm and the shifter arm to continuously urge the follower against the upper run of the bicycle chain to depress the chain; a stabilizer interconnected between the pivot arm and the shifter arm in a manner to allow substantially unrestricted counter-clockwise rotation of the shifter arm and to deter or restrict clockwise rotative movement of the shifter arm and a flexible cable interconnecting the shifter arm with the derailleur whereby the derailleur will be automatically operated to index the chain across the small diameter cluster gears in response to rotational movement of the shifter arm as caused by interaction of the bicycle chain and the follower.

Abstract: A front derailleur for a bicycle includes a chain guide reciprocably supported to a fixing member through a pair of linkage members. The chain guide has a pair of inner and outer plates opposite to each other and a coiled return spring interposed between the chain guide and either the fixing member or the linkage member. The return spring biases the chain guide in the direction of backward movement. A cap is provided to cover the spring to protect it from debris. The cap includes an elastically deformable cylindrical fitting portion to be fitted onto the coiled portion of the return spring. The cylindrical fitting portion has an axially extending slit which enables the cap to be fitted on the outer periphery of the coiled portion through expansion of the slit. The cap includes structure for positioning the cap such that the slit is adjacent to the inner plate of the chain guide.

Abstract: A rear derailleur has a chain guide which includes a guide pulley, a tension pulley, and at least one pulley plate for rotatably supporting the pulleys. A driving chain guided by the guide pulley is switched to a desired sprocket of a multistage sprocket assembly for changing the bicycle speed. The guide pulley is supported axially movably with respect to the pulley plate. Between one lateral side of the guide pulley and the inside surface of the pulley plate a gap is provided for allowing the guide pulley to move axially relative to the pulley plate by means of tension of the chain.

Abstract: A derailleur for a bicycle, which is provided with a linkage mechanism comprising a base member, a pair of linkage members and a movable member having a chain guide, in which one of the four members constituting the linkage mechanism is provided with a mounting base entering into a space in the linkage mechanism. A tightening member having at the upper end thereof a control, is mounted to the base in the relation that the tightening member extends lengthwise vertically, so that a jig inserted into the space tightens the tightening member to thereby tightly grip the control wire.

Abstract: A speed changer for a bicycle includes a plurality of sprocket wheels provided on the hub of its rear wheel and having different diameters, a transmission chain, a movable member, a chain positioning frame supported rotatably on the movable member and carrying a guide pulley and a tension pulley for guiding the chain about one of the sprocket wheels while maintaining the chain under tension, and a spring having one end fastened to the movable member for urging the frame in the direction which enables the chain to be tensioned. The other end of the spring is engaged with a mechanism mounted for rotation relative to the frame and an adjustable coupling is provided between the mechanism and the frame to vary the spring force applied to the frame to thereby vary the spring tension applied to the chain.

Abstract: A front derailleur for a bicycle having a chain guide with inner and outer plates for shifting a driving chain from one to another of at least two front chain gears. The inner plate has a swollen portion extending toward the outer plate, which urges the chain toward a larger diameter front chain gear and which is disposed between a first chain traversing position where the chain, when in the process of being shifted from a smaller diameter front chain gear to the larger diameter one, traverses the chain guide at an initial stage wherein the chain is raised by contact with the larger diameter chain gear and a second chain traversing position where the chain traverses the chain guide at the final stage wherein the chain is raised by contact with the larger diameter gear before completion of the chain shift operation.

Abstract: A fork element 1 for guiding the chain is pivotally mounted by means of a deformable parallelogram structure 11, 12 on a support constituted by an arm 3 which is upwardly and outwardly inclined relative to a vertical plane containing the longitudinal axis of the bicycle. The parallelogram structure is deformed in a plane which is inclined in a direction parallel to said arm. With this arrangement, the fork element is shifted in a constant vertical position in a combined oblique upward and advancing movement so as to shift the chain from a small chain wheel to a larger chain wheel.

Abstract: A particularly satisfactory derailer type bicycle can be constructed using front and rear derailer mechanisms in connection with the pedals and the rear wheel of the bicycle, respectively, and a control cable which operates these two mechanisms in synchronism with one another. This control cable is used so as to rotate a cam of the front derailer mechanism in order to cause shifting of the bicycle chain between the gears in this mechanism. Similarly the cable is used to concurrently rotate a cam of the rear mechanism so as to cause shifting of the bicycle chain between the gears of this mechanism. The cam as the rear derailer mechanism formed to facilitate the shifting action achieved by causing the chain of the bicycle to be moved slightly past and then back into a position corresponding to a gear of the rear mechanism.

Abstract: A derailleur for a bicycle has a base member, a movable member movable axially of a multi-stage sprocket assembly, a first feeding mechanism for moving the movable member, and a guide mechanism supported to the movable member and including a guide pulley and tension pulley for guiding the driving chain to one sprocket of the multi-stage sprocket assembly. The guide mechanism has a second feeding means including a controller actuated by operation of the first feeding mechanism to move the driving chain carried by the guide pulley axially of the multi-stage sprocket assembly by use of the movement of the chain. During changing, the chain is forcibly moved by the second feeding means to switch the chain to a desired sprocket.

Abstract: The derailleur comprises, between the conventional articulation mechanism which allows the lateral displacement of the chain guide device (12), an additional articulation mechanism (10, 11) whereby the chain guide device (12) can effect a displacement which is substantially free and of large extent in a plane perpendicular to the axis (X--X) of the crank-gear. This very substantially improves the conditions under which the chain is shifted from one chain wheel to another.

Abstract: A speed control device for a bicycle, comprising a speed control lever and a derailleur having a positioning mechanism, the speed control lever being constructed to return a movable member at the derailleur when operated in overshift, and the derailleur is constructed to move the movable member toward a sprocket to engage with a driving chain by means of a driving force acting therein when operated in undershifting.

Abstract: The derailler comprises a support 4 for a chain guiding device 12, 13 which is connected to the support by a deformable articulation structure which, under the action of a pulling cable, positions the chain guiding device relative to the free-wheel sprockets. The deformable articulation structure comprises a deformable quadrilateral structure 6, 7 to 11, at least two sides of which quadrilateral structure are unequal.

Abstract: The derailleur is shown in a retracted position allowing the dismantling of the rear wheel of the cycle. In this retracted position, it is maintained by an abutment which is rigid with the fixed part of the derailleur and is resiliently retained in a cavity defined by the concavity of a resiliently yieldable strip carried by a member fixed to the frame lug. In the operative position, the abutment is applied against the support surface of the lug.

Abstract: The speed gear device is particularly distinctive in that it includes a third movable fork side (11) mounted in a movable manner between the internal side (9a) and the external side (9b) of a fork (9) for guiding the chain (A) with a substantial spacing, in order to act in connection with the control means when the speed gear device is actuated, to guide the chain from a sprocket wheel to the other sprocket wheel.

Abstract: A speed-changing device for a bicycle, which comprises a control device having a control lever, a derailleur comprising a fitting member, a four member linkage mechanism having a chain guide and a return spring, and a control wire, said control device having a first positioning mechanism for positioning the chain guide only during returning motion of said chain guide by said return spring, said derailleur having a second positioning mechanism for positioning of said chain guide only during forward motion of said chain guide through a pulling operation of said wire.

Abstract: A linkage system is provided on a bicycle for displacing a bicycle chain between chain wheels mounted on a common axis. The linkage system includes a first linkage head fixed to a support attached to the bicycle frame and a movably positionable second linkage head connected to a device for moving the chain. An articulated lever and a guide member are connected together by a pivot joint intermediate their ends with the ends of the lever and guide member being pivotally connected to the two linkage heads. The joints connecting the lever to the linkage heads permit the lever to effect a sliding movement not available to the guide member. A mechanism for deforming the linkage system is connected to the pivot which mounts the guide member on the first linkage head.

Abstract: The disclosed speed-change gear includes a fitting secured to the frame of a bicycle, a parallel link means having an outside link and an inside link whose one ends are pivotally connected to the fitting, a movable member pivotally connected to the opposite ends of the inside and outside links, a changeover frame rotatably secured to the movable member, which changeover frame carries a guide wheel and a tension wheel of a chain, and a cam means adapted to selectively move said movable member so as to shift the speed-change ratio by changing the position of said changeover frame to shift the chain to the desired step of a multi-step sprocket assembly of the bicycle. The cam means has a spring-biased cam rotatably mounted on a shaft connecting the outside link to the fitting, which cam rotates together with a wire-operated reel coaxially mounted on said shaft. The rotation of the cam actuates said parallel link means through a lever pivotally carried by a shaft connecting the inside link to the fitting.

Abstract: A derailleur serves to change the speed of a chain driven vehicle by moving a change-over frame having a tension and a guide pulley, the change-over frame being formed of a single plate and provided with a chain holder positioning radially outwardly of the guide pulley and keeping engagement of a driving chain therewith. Interaction between the change over frame and chain during the shifting of speed is substantially reduced. Chain position is maintained by means of a chain holder reducing chain interference with the change over frame. The chain may be removed with a minimum effort without special tools.

Abstract: An improved front derailleur for a bicycle, is provided with a mounting nose extending from a base member of the derailleur and with a support mounted to the nose integrally therewith or independently thereof, the support including an insertion bore for a control wire and a socket for an outer sheath guiding the wire. The mounting nose and support have guide slots in continuation of the insertion bore and extending therefrom, the guide slot extending in a direction away from a linkage member of the derailleur. The guide slots have a length larger than the maximum wire deflection created when a control wire having no outer sheath is operated.

Abstract: A speed-changing device for a bicycle, having a pantograph mechanism which comprises four members, a supporting member, two linkage members, and movable member, is pivoted through a horizontal spindle swingably to a bracket fixed to a fork end of the bicycle. A wire holder for securing one end of a control wire is provided at one of the two linkage members and movable member, and a wire guide for guiding the control wire is disposed at a position outward with respect to the common axis of a multi-stage sprocket and beyond a phantom straight line connecting the axes of the wire holder and horizontal spindle.

Abstract: A derailleur for a bicycle comprises; a fixing member; a transformable linkage mechanism comprising a base member, two linkage members and a movable member; and a chain guide having a guide pulley and a tension pulley. The linkage mechanism is supported swingably to the fixing member in the relation that the guide pulley reciprocates away from or toward the axis of the sprocket assembly. The derailleur is provided between the chain guide and the movable member with a first spring, between the fixing member and the linkage mechanism with a second spring for biasing the guide pulley away from the axis of sprocket assembly, and with a forcibly moving mechanism which moves the chain guide axially of the sprocket assembly and also radially thereof in a plane perpendicular to the axis of the sprocket assembly.