rear derailleur

Abstract

Rear derailleur (12) comprising: a base link (18) which includes a bicycle mounting section (40) for attachment to a bicycle (10); a movable link (20) which includes a chain guide (50) having a first roller (56) which rotates about a first roller axis (A1) in a roller median plane (PL) which bisects the first roller (56); a connector (22) which movably supports the movable link (20) relative to the base link (18), wherein the connector (22) is arranged at least partially inside the roller median plane (PL), while the movable link (20) is arranged in the outermost lateral position;and an electric motor unit (24) which is stationary with respect to at least a part of the base member (18) and is operatively coupled to the connector (22) to move the movable member (20) relative to the base member (18) between an outermost lateral position and an innermost lateral position, wherein the electric motor unit (24) is arranged at least partially inside the roller median plane (PL) while the movable member (20) is arranged in the outermost lateral position, wherein the electric motor unit (24) includes an output shaft (64) which is arranged at least partially inside the roller median plane (PL) while the movable member (20) is arranged in the outermost lateral position, the roller median plane (PL) intersecting the output shaft (64).

Description

BACKGROUNDCross-Reference to Related ApplicationsThis application claims priority to U.S. patent application Ser. No. 2014 / 0 296 009 A1, filed Mar. 27, 2013. The entire disclosure of U.S. patent application with US 2014 / 0 296 009 A1 is hereby incorporated herein by reference.Field of the InventionThis invention relates to a rear derailleur for a bicycle. More specifically, the present invention relates to a rear derailleur having a connector moved by a motor unit.BACKGROUND OF THE INVENTIONA bicycle typically uses a chain drive transmission to transmit a pedal force to a rear wheel. The chain drive transmission of a bicycle often uses derailleurs to selectively move a chain from one of a plurality of sprockets to another to change the speeds of the bicycle. An ordinary derailleur includes a base member, a movable member supporting a chain guide, and a connector assembly (e.g., a moving mechanism) coupled between the base member and the movable member such that the chain guide moves laterally relative to the base member. Recently, derailleurs have been equipped with electric motor units to facilitate shifting gears. Rear derailleurs are known, for example, from DE 600 18 528 T2, FR 2 605 969 A1, US 2008 / 0 125 259 A1 and US 2008 / 0 227 572 A1.SUMMARYIt is the object of the present disclosure to provide an improved bicycle rear derailleur with a connector and an electric motor unit in a compact construction such that the amount by which the rear derailleur protrudes outside a bicycle frame is minimized and gear shifting is facilitated. This object is achieved by the features of the main claim 1. Preferred embodiments are described in the dependent claims.Other features, aspects and advantages of the disclosed rear derailleur will become apparent from the following detailed description, which, when taken in conjunction with the accompanying drawings, discloses an embodiment of the rear derailleur.BRIEF DESCRIPTION OF THE DRAWINGSReferring now to the accompanying drawings which form a part of the original disclosure: FIG. 1 is a partial side elevational view of a rear frame portion of a bicycle with a bicycle rear derailleur in an upshift step position with the chain guide in a chain engagement position; FIG. 2 is a rear end elevational view of the rear frame portion and rear derailleur illustrated in FIG. 1 in the upshift stage position but with the chain guide in the fully retracted position; FIG. 3 is a plan view of the rear frame portion and the rear derailleur illustrated in FIGS. 1 and 2 in the upshift stage position with the chain guide in the fully retracted position; FIG. 4 is a side elevational view of the rear derailleur illustrated in FIGS. 1 to 3 ; FIG. 5 is a side perspective frame view of the rear derailleur illustrated in FIGS. 1-4 with the securing mechanism in a drive transmitting position; FIG. 6 is a side perspective frame view of the rear derailleur illustrated in FIGS. 1-5 with the securing mechanism in a first non-drive transmitting position; FIG. 7 is a side perspective frame view of the rear derailleur illustrated in FIGS. 1-6 with the securing mechanism in a second non-drive transmitting position; FIG. 8 is a side elevational frame view of the base member of the rear derailleur illustrated in FIGS. 1-7 with the cover of the motor housing removed to illustrate the internal structure of the electric motor unit; FIG. 9 is a side elevational view of the movable member of the rear derailleur illustrated in FIGS. 1 to 7; FIG. 10 is a side, non-frame elevational view of the movable member of the rear derailleur illustrated in FIGS. 1-7 with a movable member cover member removed to illustrate the friction member, the friction adjustment mechanism, and the movable member one-way clutch; and FIG. 11 is another side, non-frame elevational view of the movable member of the rear derailleur illustrated in FIGS. 1-7 with the movable member cover member removed and a part of the friction adjustment mechanism removed.DETAILED DESCRIPTION OF THE EMBODIMENTSSelected embodiments will now be described with reference to the drawings. It will be apparent from this disclosure to those skilled in the art that the following descriptions of the embodiments are provided for illustrative purposes only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.Referring initially to FIGS. 1-3, illustrated therein is a rear portion of a bicycle 10 that includes, among other things, a bicycle rear derailleur 12 according to an illustrated embodiment. The rear derailleur 12 is secured to a rear portion of a bicycle frame 14 in a conventional manner as discussed below. The rear derailleur 12 is operated by an electric rear switch (not shown), which is a shift operating device. The electric rear switch operates the rear derailleur 12 between a plurality of shift speed positions (transmission positions) so that a bicycle chain 16 is moved by the rear derailleur 12 in a lateral direction between a plurality of rear sprockets S. The rear derailleur 12 is illustrated in an upshift stage position (shift position) in FIGS. 1-3. As used herein, the term "upshift stage position (shift position)" refers to the rear derailleur 12 that is in an operating position corresponding to the chain 16 guided on the rear sprocket S having the smallest number of teeth. As used herein, the term "lower shift position (shift position)" refers to the rear derailleur 12 in an operation corresponding to the chain 16 guided on the rear sprocket S having the largest number of teeth.The rear derailleur 12 generally includes a base member 18, a movable member 20, a connector 22, and an electric motor unit 24. the electric motor unit 24 is operatively coupled to the connector 22 to move the movable member 20 with respect to the base member 18. Thus, in the illustrated embodiment, the rear derailleur 12 is an electric or motorized rear derailleur. As seen in FIGS. 3-7, the connector 22 includes a securing structure 26 that operatively couples the electric motor unit 24 to the connector 22 to provide protection for the electric motor unit 24 as discussed below.In the illustrated embodiment, the base member 18 includes a first holder member 28 and a second holder member 30. the first and second holder members 28 and 30 are preferably made of a hard, rigid material, such as lightweight metal (e.g., an aluminum alloy). The first holder member 28 is an example of a first member of the base member 18, while the second holder member 30 is an example of a second member of the base member 18. The second bracket member 30 is coupled to the first bracket member 28 by a fastener 32 (e.g., a bolt). Preferably, the first link 28 and the second link 30 are together pivotally coupled by the fastener 32 about a pivot axis B defined by the central longitudinal axis of the fastener 32. The pivot axis B is sometimes called the B axis of the rear derailleur 12.The second holder member 30 includes a connector support portion 34 coupled to the connector 22 as seen in FIG. 1. As will be explained below, the connector 22 is pivotally coupled to the connector support portion 34 of the second holder member 30. The second holder member 30 further includes a fixing portion 36 and an electric motor unit supporting portion 38. the fixing portion 36 has a pair of mounting flanges 36a and 36b for receiving the first holder member 28 therebetween. The mounting flange 36a has a non-threaded bore 36c, while the mounting flange 36b has a threaded bore 36d. The fastener 32 extends through the non-threaded bore 36c and is threaded into the threaded bore 36d. The first link 28 is pivotally disposed on the fastener 32. An adjustment structure 39 is disposed on the second holder member 30. The adjusting structure 39 adjusts the pivot angle between the first holder member 28 and the second holder member 30. The adjustment structure 39 includes an adjustment bolt and a threaded hole of the second holder member 30. an axis of the adjustment bolt extends and intersects a plane including the pivot axis B. The adjustment bolt prevents rotation of the second holder member 30 counterclockwise as viewed from the outside of the bicycle 10. In this way, the electric motor unit 24 is accommodated by the base member 18. The base member 18 covers at least the outside of the electric motor unit 24. In this embodiment, the base member 18 does not cover the rear side and the lower side of the electric motor unit 24 to reduce weight. The electric motor unit 24 is detachably disposed on the electric motor unit supporting portion 38.The first bracket member 28 includes a bicycle mounting portion 40 defining a bolt receiving bore that receives a fixing bolt 42 for securing the rear derailleur 12 to the bicycle 10. Thus, the base member 18 includes the bicycle mounting portion 40 for attaching the rear derailleur 12 to the bicycle 10.As seen in FIG. 1, the second holder member 30 further includes a down-shift stage adjustment screw 44 and an up-shift stage adjustment screw 46 to adjust the range of movement of the movable member 20 with respect to the base member 18. Specifically, the low-shift stage adjustment screw 44 contacts a step of the connector 22 when the movable member 20 is in the low-shift stage position (shift position) or when the movable member 20 is slightly above the low-shift stage position (shift position). The upshift stage adjustment screw 46 contacts a step of the connector 22 when the movable member 20 is in the upshift stage position (shift position) or when the movable member 20 is slightly above the upshift stage position (shift position) as seen in FIG. 1.As seen in FIGS. 1 and 4, the movable member 20 is movably coupled to the base member 18 via the connector 22. The movable member 20 includes a chain guide 50 pivotally coupled to the movable member 20 by a shaft 52 to pivot about a chain guide pivot axis P, sometimes referred to as the P axis of the rear derailleur 12. In the illustrated embodiment, the shaft 52 is preferably made of various parts (not shown) to assist in mounting the movable member 20 and to assist in securing the chain guide 50 to the movable member 20.As best seen in FIGS. 1-4, the chain guide 50 generally includes a pair of chain cage plates 54, a tension roller 56, and a guide roller 58. In the illustrated embodiment, the guide roller 58 is rotatably disposed on the shaft 52, while the chain guide 50 is non-rotatably attached to the shaft 52.The tension roller 56 is a first roller, while the guide roller 58 is a second roller. Alternatively, the guide roller 58 constitutes a first roller, while the tension roller 56 constitutes a second roller. The tension roller 56 (first roller) rotates about a first roller axis A 1 in a roller center plane PL bisecting the tension roller 56 (first roller). The guide roller 58 (second roller) rotates about a second roller axis A 2 in the roller center plane PL bisecting the guide roller 58 (second roller). Thus, in the illustrated embodiment, the rollers 56 and 58 have the same roller center plane PL. The roller center plane in the claims refers to the roller center plane PL of the guide roller 58. the roller center plane PL bisects the center of the guide roller 58 (second roller) in the direction of the roller axis A2 and is orthogonal to the roller axis A2.Referring now to FIGS. 1, 4 and 5, the connector 22 will be explained in more detail. The connector 22 movably supports the movable member 20 relative to the base member 18. in other words, the connector 22 operatively connects the movable member 20 to the base member 18. the connector 22 is disposed at least partially inside the roller center plane PL while the movable member 20 is disposed at the outermost lateral position corresponding to the upshift stage position (shift position) of the rear derailleur 12.In the illustrated embodiment, the connector 22 includes a first link or inner link 60 pivotally connected to the base member 18 and to the movable member 20. The connector 22 further includes a second link or outer link 62 pivotally connected to the base member 18 and the movable member 20. The inner link 60 has a first end pivotally connected to the base member 18 by an output shaft 64 of the electric motor unit 24. The inner link 60 has a second end pivotally connected to the movable member 20 by a pivot pin 66. The outer link 62 has a first end pivotally connected to the base member 18 by the pivot pin 68. The outer link 62 has a second end pivotally connected to the movable member 20 by a pivot pin 70. Thus, the inner link and outer link 60 and 62 have first ends pivotally connected to the base member 18 and second ends pivotally connected to the movable member 20 to define a four-point hinge arrangement and a four-pivot arm arrangement, respectively. The pivot axis of the output shaft 64 of the electric motor unit 24 and the pivot axes of the pivot pins 66, 68, and 70 are inclined relative to the roller plane PL. More specifically, the pivot axes of the output shaft 64 and the pivot pins 66, 68, and 70 are inclined in a downward direction, while the output shaft 64 and the pivot pins 66, 68, and 70 extend outwardly away from a vertical center plane of the bicycle frame 14. Consequently, the inner ends of the output shaft 64 and the pivot pins 66, 68, and 70 are located higher than the outer ends of the output shaft 64 and the pivot pins 66, 68, and 70.As seen in FIG. 5, the connector 22 further includes a biasing member 72 interposed between the inner and outer links 60 and 62 to bias the movable member 20 toward one of the low-shift position or the high-shift position. In the illustrated embodiment, the biasing member 72 is a helical tension spring that biases the movable member 20 toward the low shift stage position. With this arrangement, the biasing member 72 is / is elongated as the movable member 20 moves from the low shift stage position to the upshift stage position. In the low shift stage position, the biasing member 72 is biased (slightly stretched) to be / are stabilized in the low shift stage position. In the upshift stage position, the biasing member 72 is / is biased (slightly stretched) to be stabilized in the upshift stage position as seen in FIG. 1.The biasing member 72 assists in / accommodating / compensating play or clearance between the gears of the electric motor unit 24 and other manufacturing tolerances in manufacturing the rear derailleur 12. Consequently, the biasing member 72 improves stability of the shift positions of the rear derailleur 12.In the illustrated embodiment, the internal link 60 includes a first link 76 and a second link 78, but the internal link 60 may be made of a single piece if needed and / or desired. The second link 78 is fixed to an intermediate portion of the first link 76 by the mounting member 74. the first link 76 forms the second end of the inner link 60 which is pivotally connected to the movable member 20 by a pivot pin 66. The first and second link members 76 and 78 form the first end of the inner link 60, and each has an end portion pivotally connected to the base member 18 by way of one end of the output shaft 64 of the electric motor unit 24. More specifically, the first and second links 76 and 78 are not fixed to the output shaft 64, but rather, the output shaft 64 can rotate relative to the end portions of the first and second links 76 and 78. When assembling the rear derailleur 12, it is easy to fix the inner link 60 to the output shaft 64 of the electric motor unit 24 as a pivot shaft of the inner link 60, because the inner link 60 is constructed by a plurality of parts.Now, the electric motor unit 24 will be explained in more detail by referring primarily to Figs. 2 to 4 and 8, the electric motor unit 24 is arranged at least partially inside the roller center plane PL while the movable member 20 is arranged at the extreme lateral position as seen in Figs. 2 and 3. The electric motor unit 24 includes a motor housing 82 and a motor 84. the motor 84 is fixed inside the motor housing 82, which includes a shell portion 82 aand a lid portion 82 b. The motor 84 is a reversible electric motor. The electric motor unit 24 further includes a reduction gear unit 86 also disposed within the motor housing 82. The output shaft 64 of the electric motor unit 24 is connected to an output shaft of the motor 84 via the reduction gear unit 86. Rotation of the output shaft 64 in one direction moves the movable member 20 and the chain guide 50 toward a low gear position with respect to the base member 18. rotation of the output shaft 64 in another direction moves the movable member 20 and the chain guide 50 toward a high gear position with respect to the base member 18.The electric motor unit 24 further includes a motor unit mounting bracket disposed at least partially inside the roller center plane PL while the movable member 20 is disposed at the outermost lateral position. The motor unit mounting bracket is coupled to the base member 18 by three screws. The motor unit mounting bracket holds the motor housing 82 in the recess 38 aof the motor unit support portion 38 of the base member 18. Thus, the motor unit 24 is stationary with respect to at least a part of the base member 18, and is operatively coupled to the connector 22 to move the movable member 20 relative to the base member 18 between an outermost lateral position (i.e., the upshift stage position in the illustrated embodiment) and an innermost lateral position (i.e., the downshift stage position in the illustrated embodiment). The motor housing 82, the motor 84, and the reduction gear unit 86 are at least partially disposed inside the roller center plane PL, while the movable member 20 is disposed at the outermost lateral position (i.e., the upshift stage position in the illustrated embodiment) as seen in FIG. 2.The electric motor unit 24 includes the output shaft 64 disposed at least partially inside the roller center plane PL while the movable member 20 is disposed at the extreme lateral position as viewed in FIG. 3. The output shaft 64 is connected to the inner link 60 to drive the connector 22 to move the movable member 20 in a lateral direction in response to rotation of the output shaft 64 by the motor 84. In this embodiment, the roller center plane PL intersects the output shaft 64, and the output shaft 64 of the electric motor unit 24 is rotatably mounted to the motor housing 82 to protrude at opposite ends of the motor housing 82 to pivotally support the inner link 60 on the base member 18. The output shaft 64 of the electric motor unit 24 drives the inner link 60 to move the movable member 20 with respect to the base member 18. The outer link 62 moves in response to movement of the inner link 60, and the output shaft 64 of the electric motor unit 24 is usually connected to the inner link 60 via the securing structure 26 as explained below.As seen in FIG. 3, the lid portion 82 of the electric motor unit 24 includes an electric wire receiver 82 carranged at least partially inside the roller center plane PL, while the movable member 20 is arranged at the outermost lateral position. The electric wire receiver 82 cacquires an electric wire W of the motor 84. The electric wire of the motor 84 is electrically connected to a remote power source that powers the motor 84 to actuate the motor 84.The fuse structure 26 will now be explained in more detail with reference to FIGS. 3 to 7. The securing structure 26 is at least partially disposed inside the roller center plane PL while the movable member 20 is disposed at the extreme lateral position as seen in FIG. 3. The securing structure 26 includes an output member 94, a drive link 96, and a biasing member 98. the securing structure 26 is movably disposed between a drive transmission position that connects a drive force of the electric motor unit 24 to the first or inner link 60 and a non-drive transmission position that disconnects the drive force of the electric motor unit 24 from the first or inner link 60.The fuse structure 26 substantially performs two functions. First, the securing structure 26 normally transmits a driving force of the motor 84 to the inner link 60 to move the movable member 20 with respect to the base member 18. Secondly, the securing structure 26 stops transmission of a driving force of the motor 84 to the inner link 60, so that the motor unit 84 can be further operated even if the movable member 20 is not moved (e.g., pinched) with respect to the base member 18 or the force to move the movable member 20 with respect to the base member 18 becomes larger than a predetermined operating force. In this way, the electric motor unit 24 is protected by means of the securing structure 26 in certain situations.As seen in FIGS. 4 to 7, the output member 94 is movably operated by the motor 84 of the electric motor unit 24. Specifically, the output member 94 is fixed to the output shaft 64 of the electric motor unit 24 to rotate with the output shaft 64. For example, the output member 94 is fixed to the output shaft 64 of the electric motor unit 24 by spline connection as illustrated. In this way, the output member 94 is rotated as soon as the output shaft 64 of the electric motor unit 24 is rotated by the operation of the motor 84. The motive force (i.e., torque) of the output member 94 is transmitted to the first link 76 of the inner link 60 via the drive link 96. More specifically, the drive link 96 is pivotally mounted to the inner link 60 to move between a drive transmission position that connects a driving force of the motor 84 to the inner link 60 and a non-drive transmission position that separates the driving force of the motor 84 from the inner link 60. The biasing member 98 exerts a biasing force on the drive link 96 to bias the drive link 96 into contact with the output member 94. The drive link 96 is engaged with the output member 94 to move together while the drive link 96 is in the drive transmitting position. On the other hand, the drive link 96 disengages from the output member 94 to provide relative movement between the drive link 96 and the output member 94 while the drive link 96 is in the non-drive transmission position. The drive link 96 moves from the drive transmission position to the non-drive transmission position against a predetermined resistance occurring at the inner link 60 that overcomes the biasing force of the biasing member 98 at the drive link 96.As seen in FIGS. 4-7, the biasing member 98 applies a biasing force to the drive link 96 to bias the drive link 96 into engagement with the output member 94. Consequently, the output shaft 64 of the electric motor unit 24 is connected to the inner link 60 via the output member 94 and the drive link 96 as a result of the biasing member 98, so that the driving force of the motor 84 is transmitted to the inner link 60 to move the movable member 20 with respect to the base member 18. The biasing member 98 applies a biasing force to the drive link 96 in engagement with the output member 94 to maintain the drive link 96 in the drive transmitting position. Consequently, this arrangement of the output member 94, the drive link 96 and the biasing member 98 provides a overwindable connection between the output shaft 64, the electric motor unit 24 and the inner link 60, in which the connection between the output shaft 64, the electric motor unit 24 and the inner link 60 is switched from the drive transmission position to the non-drive transmission position with a force exceeding the predetermined operating force required to move the movable member 20 with respect to the base member 18. In the illustrated embodiment, the biasing member 98 is a coil spring.In the illustrated embodiment, the overwindable connection between the output shaft 64 of the electric motor unit 24 and the inner link 60 is established by providing the output engagement portion 96a or the output member 94 having a notch and the other one of the output engagement portion 96a or the output member 94 having a protrusion that mates with the notch to establish the drive transmission position. For example, as illustrated, the output member 94 includes a notch 94 aand the output engagement portion 96 aincludes a protrusion that mates with the notch 94 ato establish the drive transmission position.FIGS. 6 and 7 illustrate situations in which the movable member 20 does not move (e.g., pinch) with respect to the base member 18, or for a reason, the force to move the movable member 20 with respect to the base member 18 becomes greater than a prescribed operating force predetermined by the biasing force of the biasing member 98. If the movable member 20 is pinched and the output shaft 64 of the electric motor unit 24 is driven by the motor 84, the securing structure 26 will allow the output shaft 64 of the electric motor unit 24 to rotate. In particular, the output member 94 will behave as a cam that moves the drive link 96 against the biasing force of the biasing member 98. This movement of the drive link 96 by the output member 94 against the biasing force of the biasing member 98 results in the output engagement portion 96 a(e.g., protrusion) of the drive link 96 being displaced from the notch 94 aof the output member 94 onto a cam surface 94 bof the output member 94. Once the output engagement portion 96 aremain on the cam surface 94 b, the output shaft 94 of the electric motor unit 24 can rotate without transmitting the driving force to the inner link 60. The cam surface 94b of the output member 94 extends in both circumferential directions from the notch 94a of the output member 94, in which way the motor 84 is protected in both operating directions.Although not shown, the electric motor unit 24 may be provided with a shift stage position sensor, such as a digital position sensor, mounted on the reduction gear unit 86 to detect movement of one of the parts of the reduction gear unit 86. In particular, the shift stage position sensor may be provided by means of a position sensor shutter wheel and a dual channel photo interrupter comprising a light source or LED arranged on one side of the shutter wheel and a phototransistor (e.g. a light detector) arranged on the other side of the shutter wheel. The shift stage position sensor may be formed by a magneto resistance sensor or a magnet. The magnet is disposed at a part of the reduction gear.As seen in FIG. 9, the movable member 20 is provided with a biasing member 100. The biasing member 100 is provided between the movable member 20 and the chain guide 50 to bias the chain guide 50 about the chain guide pivot axis P in a first rotational direction D 1 (see FIGS. 9 and 10 ). Thus, the first rotation direction D 1 is a clockwise rotation direction of the chain guide 50 about the chain guide pivot axis P when viewed along the chain guide pivot axis P from the non-frame facing side of the movable member 20. In the illustrated embodiment, the biasing member 100 is a torsion spring having a wound portion disposed around the shaft 52, a first spring end 100 aengaged with the movable member 20, and a second spring end 100 bengaged (i.e., hooked) with the chain guide 50.As seen in FIGS. 10 and 11, in the illustrated embodiment, the movable member 20 is provided with a friction member 102 operatively disposed between the movable member 20 and the chain guide 50. The friction member 102 frictionally provides rotational resistance in a second rotational direction D 2 of the chain guide 50 about the chain guide pivot axis P. Preferably, the friction member 102 is adjustable to vary the rotational resistance provided by the friction member 102 through a friction adjustment mechanism 104. Substantially, the friction member 102 increases an operation performance of the electric motor unit 24 as the electric motor unit 24 moves the movable member 20 toward the low speed position with respect to the base member 18. The friction member 102 constitutes a resistance applying member. In this illustrated embodiment, a one-way clutch 106 is disposed between the friction member 102 and the shaft 52. The friction member 102 resists the rotational movement of the chain guide 50 in the second rotational direction D 2 with respect to the movable member 20. Specifically, the friction member 102 applies frictional resistance to the rotational movement of the chain guide 50 by applying frictional resistance to the rotation of the one-way clutch 106. Since the resistance applying members and the one-way clutches are similar to the friction member 102 and the one-way clutch 106 explained in detail in U.S. Patent Application Publication No. 2012 / 0 083 371 A1, the friction member 102 and the one-way clutch 106 will not be explained in further detail herein.The terms "connect" or "connected" as used herein are intended to include configurations in which one element is directly secured to another element by adhering the element directly to the other element; configurations in which the element is indirectly secured to the other element by adhering the element to an intermediate member(s) which is(s) in turn attached to the other element; and configurations in which one element is integrally formed with another element, i.e., one element is a unitary part of the other element. For example, the magnetized part may be directly secured to the crank arm attachment part or may be indirectly secured to the crank arm attachment part through an intermediate member(s), or may be integrally formed with the crank arm attachment part. These definitions also apply to words of similar meaning, e.g., the terms "attach", "attached", "connect", "connected", "fix", "fixed", "glue", "glued", "couple", "coupled", and their derivatives.While only preferred embodiments have been chosen to illustrate the present invention, it will be apparent to one skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims. For example, the size, shape, location, or orientation of the various components may be varied as needed and / or desired, as long as they do not substantially lose their particular function. Components shown as directly connected or touching each other may have intermediate structures disposed between them unless otherwise stated. The functions of one element may also be performed by two and vice versa, unless otherwise stated. The structures and functions may be adjusted from one embodiment to another embodiment. It is not necessary for all advantages to be present at the same time in a particular embodiment. Each feature that is unique to the prior art, alone or in combination with other features, is intended to be considered a separate description of other inventions by the applicant, including the structural and / or functional concepts embodied by these features. Accordingly, the foregoing descriptions of the embodiments according to the present invention are provided for illustrative purposes only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

Claims

A rear derailleur (12) comprising: a base member (18) including a bicycle mounting portion (40) for attachment to a bicycle (10); a movable member (20) including a chain guide (50) having a first roller (56) that rotates about a first roller axis (A1) in a roller center plane (PL) bisecting the first roller (56); a connector (22) movably supporting the movable member (20) relative to the base member (18), the connector (22) being at least partially disposed inboard of the roller center plane (PL) while the movable member (20) is disposed in the outboard lateral position; and an electric motor unit (24) which is stationary with respect to at least a part of the base member (18) and is operatively coupled to the connector (22) to move the movable member (20) relative to the base member (18) between an outermost lateral position and an innermost lateral position, the electric motor unit (24) being arranged at least partially inside the roller center plane (PL) while the movable member (20) is arranged in the outermost lateral position, the electric motor unit (24) including an output shaft (64) arranged at least partially inside the roller center plane (PL) while the movable member (20) is arranged in the outermost lateral position, the roller center plane (PL) intersecting the output shaft (64).The rear derailleur (12) according to claim 1, wherein the output shaft (64) of the electric motor unit (24) is rotatably mounted to a motor housing (82) to project at opposite ends of the motor housing (82) to pivotally support an internal link (60) on the base member (18).The rear derailleur (12) according to claim 1 or 2, wherein the connector (22) includes an / the inner link (60) pivotally connected to the base member (18) and the movable member (20), the output shaft (64) being connected to the inner link (60).The rear derailleur (12) according to any one of claims 1 to 3, wherein the electric motor unit (24) includes an electric wire receiver (82c) disposed at least partially inside the roller center plane (PL) while the movable member (20) is disposed in the extreme lateral position.The rear derailleur (12) according to any one of claims 1 to 4, wherein the electric motor unit (24) includes a motor unit mounting bracket disposed at least partially inward of the roller center plane (PL) while the movable member (20) is disposed in the extreme lateral position, in particular the motor unit mounting bracket is coupled to the base member (18).The rear derailleur (12) according to any one of claims 1 to 5, wherein the electric motor unit (24) includes a motor (84) disposed at least partially inside the roller center plane (PL) while the movable member is. (20) is disposed at the outermost lateral position.Rear derailleur (12) according to any of claims 1 to 6, wherein the connector (22) includes a securing structure (26) arranged at least partially inside the roller centre plane (PL) while the movable member (20) is arranged in the extreme lateral position.The rear derailleur (12) according to claim 7, wherein the connector (22) includes a first link (60) pivotally connected to the base member (18) and to the movable member (20), and wherein the securing structure (26) is movably disposed between a drive transmission position connecting a driving force of the electric motor unit (24) to the first link (60) and a non-drive transmission position disconnecting the driving force of the electric motor unit (24) from the first link (60).The rear derailleur (12) according to any one of claims 1 to 8, wherein the base member (18) includes a first member (28) and a second member (30), wherein the second member (30) is coupled to the first member (28), wherein the first member (28) includes the bicycle mounting portion (40), and wherein the second member (30) includes a connector support portion (34) coupled to the connector (22).The rear derailleur (12) of claim 9, wherein the first link (28) and the second link (30) are pivotally coupled together.Rear derailleur (12) according to any of claims 1 to 10, wherein the electric motor unit (24) is accommodated by the base member (18).

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