Bicycle derailleur

The present invention relates to a bicycle derailleur.

Discussion of the Background

Japanese Patent Application Publication H09-086472 describes a pulley of a rear derailleur. For example, FIGS. 1 to 6 of H09-086472 illustrate a bearing supporting the pulley.

In accordance with a first aspect of the present invention, a bicycle derailleur comprises a base member, a movable member, and a chain guide. The base member is configured to be attached to a bicycle frame. The movable member is configured to be movable relative to the base member. The chain guide is mounted to the movable member. The chain guide comprises an inner guide plate, an outer guide plate, at least one pulley axle, and at least one pulley. The at least one pulley axle is configured to be coupled to the inner guide plate and the outer guide plate. The at least one pulley is configured to be rotatably supported around the at least one pulley axle. The chain guide is configured to be movable between a plurality of shifting positions. The at least one pulley is configured to be movable between the inner guide plate and the outer guide plate within a maximum pulley movable amount in a pulley axial direction with respect to a rotational center axis of the at least one pulley. A single shifting distance is defined between adjacent shifting positions of the plurality of shifting positions. A ratio of the maximum pulley movable amount to the single shifting distance ranges from 0.21 to 0.35.

With the bicycle derailleur according to the first aspect, a position of the at least one pulley can be automatically and effectively adjusted in the pulley axial direction when an actual position of the chain guide is offset from the shifting position in the pulley axial direction. Thus, it is possible to absorb error of the position of the chain guide, improving a shifting operation of a bicycle chain. Furthermore, the position of the at least one pulley can be automatically and effectively adjusted in the pulley axial direction when the chain guide is moved from a current shifting position to an adjacent shifting position to shift the bicycle chain from a current sprocket to an adjacent sprocket. This can smooth the movement of the bicycle chain from the current sprocket to the adjacent sprocket during the shifting operation.

In accordance with a second aspect of the present invention, the bicycle derailleur according to the first aspect is configured so that the ratio of the maximum pulley movable amount to the single shifting distance ranges from 0.24 to 0.30.

With the bicycle derailleur according to the second aspect, a position of the at least one pulley is automatically and more effectively adjusted in the pulley axial direction when the actual position of the chain guide is offset from the shifting position in the pulley axial direction. Thus, it is possible to further absorb error of the position of the chain guide, improving a shifting operation of the bicycle chain. Furthermore, the position of the at least one pulley can be automatically and more effectively adjusted in the pulley axial direction when the chain guide is moved from a current shifting position to an adjacent shifting position to shift the bicycle chain from a current sprocket to an adjacent sprocket. This can smooth the movement of the bicycle chain from the current sprocket to the adjacent sprocket during the shifting operation.

In accordance with a third aspect of the present invention, the bicycle derailleur according to the first or second aspect is configured so that the plurality of shifting positions includes at least nine shifting positions.

With the bicycle derailleur according to the third aspect, it is possible to improve the shifting operation of the bicycle chain in a multistage sprocket corresponding to the at least nine shifting positions.

In accordance with a fourth aspect of the present invention, the bicycle derailleur according to the first or second aspect is configured so that the plurality of shifting positions includes at least eleven shifting positions.

With the bicycle derailleur according to the fourth aspect, it is possible to improve the shifting operation of the bicycle chain in a multistage sprocket corresponding to the at least eleven shifting positions.

In accordance with a fifth aspect of the present invention, the bicycle derailleur according to any one of the first to fourth aspects is configured so that the at least one pulley axle includes a guide-pulley axle and a tension-pulley axle. The at least one pulley includes a guide pulley and a tension pulley. The guide pulley is configured to be rotatably supported around the guide-pulley axle. The tension pulley is configured to be rotatably supported around the tension-pulley axle. The guide pulley is configured to be movable between the inner guide plate and the outer guide plate within the maximum pulley movable amount in the pulley axial direction.

With the bicycle derailleur according to the fifth aspect, the maximum pulley movable amount can enlarge an area where a position of the guide pulley is automatically adjusted within in the pulley axial direction when an actual position of the chain guide is offset from the shifting position in the pulley axial direction. Thus, it is possible to absorb error of the position of the chain guide, improving a shifting operation of the bicycle chain.

In accordance with a sixth aspect of the present invention, the bicycle derailleur according to the fifth aspect is configured so that the at least one pulley axle further includes an additional pulley axle. The at least one pulley further includes an additional pulley configured to be rotatably supported around the additional pulley axle.

With the bicycle derailleur according to the sixth aspect, it is possible to improve the shifting operation of the bicycle chain in the bicycle derailleur including at least three pulley.

In accordance with a seventh aspect of the present invention, the bicycle derailleur according to any one of the first to fifth aspects is configured so that the at least one pulley includes a pulley body and a plurality of pulley teeth extending radially outwardly from the pulley body with respect to the rotational center axis. The plurality of pulley teeth includes at least one first pulley tooth and at least one second pulley tooth. The at least one first pulley tooth has a first chain-engaging axial width. The at least one second pulley tooth has a second chain-engaging axial width that is smaller than the first chain-engaging axial width.

With the bicycle derailleur according to the seventh aspect, it is possible to improve the shifting operation the bicycle chain having the first chain-engaging axial width and the second chain engaging-axial width.

In accordance with an eighth aspect of the present invention, the bicycle derailleur according to the seventh aspect is configured so that the at least one first pulley tooth is configured to engage with a pair of opposed outer link plates of a bicycle chain. The at least one second pulley tooth is configured to engage with a pair of opposed inner link plates of the bicycle chain.

With the bicycle derailleur according to the eighth aspect, it is possible to effectively improve the shifting operation the bicycle chain having the first chain-engaging axial width and the second chain engaging-axial width.

In accordance with a ninth aspect of the present invention, a bicycle derailleur comprises a base member, a movable member, and a chain guide. The base member is configured to be attached to a bicycle frame. The movable member is configured to be movable relative to the base member. The chain guide is mounted to the movable member. The chain guide comprises an inner guide plate, an outer guide plate, at least one pulley axle, and at least one pulley. The at least one pulley axle is configured to be coupled to the inner guide plate and the outer guide plate. The at least one pulley is configured to be rotatably supported around the at least one pulley axle. The chain guide is configured to be movable between a plurality of shifting positions. The at least one pulley is configured to be movable between the inner guide plate and the outer guide plate within a maximum pulley movable amount in a pulley axial direction with respect to a rotational center axis of the at least one pulley. A single shifting distance is defined between adjacent shifting positions of the plurality of shifting positions. The single shifting distance is smaller than 4.8 mm. The maximum pulley movable amount is larger than 0.8 mm.

With the bicycle derailleur according to the ninth aspect, a position of the at least one pulley can be automatically and effectively adjusted in the pulley axial direction when an actual position of the chain guide is offset from the shifting position in the pulley axial direction. Thus, it is possible to absorb error of the position of the chain guide, improving a shifting operation of the bicycle chain. Furthermore, the position of the at least one pulley can be automatically and effectively adjusted in the pulley axial direction when the chain guide is moved from a current shifting position to an adjacent shifting position to shift the bicycle chain from a current sprocket to an adjacent sprocket. This can smooth the movement of the bicycle chain from the current sprocket to the adjacent sprocket during the shifting operation.

In accordance with a tenth aspect of the present invention, the bicycle derailleur according to the ninth aspect is configured so that the single shifting distance is smaller than 4.5 mm.

With the bicycle derailleur according to the tenth aspect, it is possible to improve the shifting operation of the bicycle chain in a compact multistage sprocket.

In accordance with an eleventh aspect of the present invention, the bicycle derailleur according to the ninth aspect is configured so that the single shifting distance is smaller than 4.2 mm.

With the bicycle derailleur according to the eleventh aspect, it is possible to improve the shifting operation of the bicycle chain in a more compact multistage sprocket.

In accordance with a twelfth aspect of the present invention, the bicycle derailleur according to the ninth aspect is configured so that the single shifting distance is larger than 3.5 mm.

With the bicycle derailleur according to the twelfth aspect, it is possible to improve the shifting operation of the bicycle chain in a more compact multistage sprocket.

In accordance with a thirteenth aspect of the present invention, the bicycle derailleur according to any one of the ninth to twelfth aspects is configured so that the maximum pulley movable amount is larger than 0.9 mm.

With the bicycle derailleur according to the thirteenth aspect, it is possible to further improve the shifting operation of the bicycle chain.

In accordance with a fourteenth aspect of the present invention, the bicycle derailleur according to any one of the ninth to thirteenth aspects is configured so that the maximum pulley movable amount is smaller than 1.5 mm.

With the bicycle derailleur according to the fourteenth aspect, it is possible to further improve the shifting operation of the bicycle chain.

In accordance with a fifteenth aspect of the present invention, the bicycle derailleur according to any one of the ninth to fourteenth aspects is configured so that the plurality of shifting positions includes at least nine shifting positions.

With the bicycle derailleur according to the fifteenth aspect, it is possible to improve the shifting operation of the bicycle chain in a multistage sprocket corresponding to the at least nine shifting positions.

In accordance with a sixteenth aspect of the present invention, the bicycle derailleur according to any one of the ninth to fourteenth aspects is configured so that the plurality of shifting positions includes at least eleven shifting positions.

With the bicycle derailleur according to the sixteenth aspect, it is possible to improve the shifting operation of the bicycle chain in a multistage sprocket corresponding to the at least eleven shifting positions.

In accordance with a seventeenth aspect of the present invention, the bicycle derailleur according to any one of the ninth to sixteenth aspects is configured so that the at least one pulley axle includes a guide-pulley axle and a tension-pulley axle. The at least one pulley includes a guide pulley and a tension pulley. The guide pulley is configured to be rotatably supported around the guide-pulley axle. The tension pulley is configured to be rotatably supported around the tension-pulley axle. The guide pulley is configured to be movable between the inner guide plate and the outer guide plate within the maximum pulley movable amount in the pulley axial direction.

With the bicycle derailleur according to the seventeenth aspect, a position of the guide pulley is automatically and effectively adjusted in the pulley axial direction when an actual position of the chain guide is offset from the shifting position in the pulley axial direction. Thus, it is possible to absorb error of the position of the chain guide, improving a shifting operation of the bicycle chain. Furthermore, the position of the at least one pulley can be automatically and more effectively adjusted in the pulley axial direction when the chain guide is moved from a current shifting position to an adjacent shifting position to shift the bicycle chain from a current sprocket to an adjacent sprocket. This can smooth the movement of the bicycle chain from the current sprocket to the adjacent sprocket during the shifting operation.

In accordance with an eighteenth aspect of the present invention, the bicycle derailleur according to the seventeenth aspect is configured so that the at least one pulley axle further includes an additional pulley axle. The at least one pulley further includes an additional pulley configured to be rotatably supported around an additional pulley axle.

With the bicycle derailleur according to the eighteenth aspect, it is possible to improve the shifting operation of the bicycle chain in the bicycle derailleur including at least three pulley.

In accordance with a nineteenth aspect of the present invention, the bicycle derailleur according to any one of the ninth to eighteenth aspects is configured so that the at least one pulley includes a pulley body and a plurality of pulley teeth extending radially outwardly from the pulley body with respect to the rotational center axis. The plurality of pulley teeth includes at least one first pulley tooth and at least one second pulley tooth. The at least one first pulley tooth has a first chain-engaging axial width. The at least one second pulley tooth has a second chain-engaging axial width that is smaller than the first chain-engaging axial width.

With the bicycle derailleur according to the nineteenth aspect, it is possible to improve the shifting operation the bicycle chain having the first chain-engaging axial width and the second chain engaging-axial width.

In accordance with a twentieth aspect of the present invention, the bicycle derailleur according to the nineteenth aspect is configured so that the at least one first pulley tooth is configured to engage with a pair of opposed outer link plate of a bicycle chain. The at least one second pulley tooth is configured to engage with a pair of opposed inner link plate of the bicycle chain.

With the bicycle derailleur according to the twentieth aspect, it is possible to effectively improve the shifting operation the bicycle chain having the first chain-engaging axial width and the second chain engaging-axial width.

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

FIG. 1 is a side elevational view of a drive train including a bicycle derailleur in accordance with an embodiment.

FIG. 2 is a rear view of the bicycle derailleur of the drive train illustrated in FIG. 1 .

FIG. 3 is another side elevational view of the bicycle derailleur of the drive train illustrated in FIG. 1 .

FIG. 4 is a top view of a bicycle chain of the drive train illustrated in FIG. 1 .

FIG. 5 is a cross-sectional view of a guide pulley of the bicycle derailleur illustrated in FIG. 3 .

FIG. 6 is a cross-sectional view of a tension pulley of the bicycle derailleur illustrated in FIG. 3 .

FIG. 7 is a cross-sectional view of the guide pulley of the bicycle derailleur illustrated in FIG. 3 .

FIG. 8 is a cross-sectional view of the tension pulley of the bicycle derailleur illustrated in FIG. 3 .

FIG. 9 is a perspective view of a bicycle derailleur in accordance with a first modification of the embodiment.

FIG. 10 is a side elevational view of a pulley of a bicycle derailleur in accordance with a second modification of the embodiment.

FIG. 11 is a cross-sectional view of a guide pulley of the bicycle derailleur in accordance with the second modification of the embodiment.

FIG. 12 is a cross-sectional view of the tension pulley of the bicycle derailleur in accordance with the second modification of the embodiment.

FIG. 13 is a top view of a bicycle chain corresponding to the bicycle derailleur in accordance with the second modification.

The embodiment(s) will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings.

As seen in FIG. 1 , a drive train DT comprises a bicycle derailleur 10 in accordance with an embodiment, a bicycle sprocket assembly SP, and a bicycle chain C. The bicycle derailleur 10 comprises a base member 12 , a movable member 14 , and a chain guide 16 . The base member 12 is configured to be attached to a bicycle frame BF. The base member 12 is secured to the bicycle frame BF with a fastener 18 such as a bolt. The movable member 14 is configured to be movable relative to the base member 12 . The chain guide 16 is mounted to the movable member 14 . The chain guide 16 is configured to shift the bicycle chain C relative to the bicycle sprocket assembly SP. The bicycle sprocket assembly SP is rotatable relative to the bicycle frame BF about a rotational axis A 1 .

In this embodiment, the bicycle derailleur 10 is configured to be connected to an operating device 2 with a mechanical cable MC. The bicycle derailleur 10 is mounted to the bicycle frame BF to shift the bicycle chain C relative to the bicycle sprocket assembly SP in response to a movement of an inner wire MC 1 of the mechanical cable MC.

The bicycle derailleur 10 includes a linkage structure 20 configured to movably couple the movable member 14 to the base member 12 . The linkage structure 20 includes a first link 22 , a second link 24 , a first link pin 26 , a second link pin 28 , a third link pin 30 , and a fourth link pin 32 . The first link pin 26 defines a first link axis LA 1 . The second link pin 28 defines a second link axis LA 2 . The third link pin 30 defines a third link axis LA 3 . The fourth link pin 32 defines a fourth link axis LA 4 . The first link axis LA 1 , the second link axis LA 2 , the third link axis LA 3 , and the fourth link axis LA 4 are parallel to or substantially parallel to each other.

The chain guide 16 is pivotally coupled to the movable member 14 about a pivot axis PA. The first link pin 26 pivotally couples the first link 22 to the base member 12 about the first link axis LA 1 . The second link pin 28 pivotally couples the second link 24 to the base member 12 about the second link axis LA 2 . The third link pin 30 pivotally couples the first link 22 to the movable member 14 about the third link axis LA 3 . The fourth link pin 32 pivotally couples the second link 24 to the movable member 14 about the fourth link axis LA 4 . The first link 22 , the second link 24 , the first link pin 26 , the second link pin 28 , the third link pin 30 , and the fourth link pin 32 constitute a four-bar linkage. However, the structures of the movable member 14 and the linkage structure 20 are not limited to this embodiment.

At least one of the first link 22 and the second link 24 includes a wire fastener 38 . In this embodiment, the first link 22 includes the wire fastener 38 . However, the second link 24 or both the first link 22 and the second link 24 can include the wire fastener 38 . The wire fastener 38 is configured to couple the inner wire MC 1 of the mechanical cable MC. The first link 22 and the second link 24 pivot relative to the base member 12 in response to the movement of the inner wire MC 1 .

As seen in FIG. 2 , an inclination angle AG of the first link axis LA 1 relative to a vertical line VL is equal to or smaller than 20 degrees in a state where the bicycle derailleur 10 is mounted to the bicycle frame BF. The vertical line VL is an imaginary line parallel to a center plane of the bicycle frame BF. The inclination angle AG is preferably equal to or smaller than 15 degrees. However, the inclination angle AG is not limited to this embodiment and the above ranges.

The chain guide 16 is configured to be movable between a plurality of shifting positions. A single shifting distance SD is defined between adjacent shifting positions of the plurality of shifting positions. The single shifting distance SD is defined between adjacent shifting positions of the plurality of shifting positions in a pulley axial direction D 1 .

The plurality of shifting positions includes at least nine shifting positions. The plurality of shifting positions includes at least eleven shifting positions. In this embodiment, the plurality of shifting positions includes eleven shifting positions P 1 to P 11 . The operating device 2 is configured to position the inner wire MC 1 relative to the outer casing MC 2 in one of eleven operation positions respectively corresponding to the shifting position P 1 to P 11 . However, a total number of the shifting positions is not limited to this embodiment.

A single shifting distance SD 1 is defined between adjacent shifting positions P 1 and P 2 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 2 is defined between adjacent shifting positions P 2 and P 3 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 3 is defined between adjacent shifting positions P 3 and P 4 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 4 is defined between adjacent shifting positions P 4 and P 5 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 5 is defined between adjacent shifting positions P 5 and P 6 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 6 is defined between adjacent shifting positions P 6 and P 7 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 7 is defined between adjacent shifting positions P 7 and P 8 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 8 is defined between adjacent shifting positions P 8 and P 9 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 9 is defined between adjacent shifting positions P 9 and P 10 of the plurality of shifting positions P 1 to P 11 . A single shifting distance SD 10 is defined between adjacent shifting positions P 10 and P 11 of the plurality of shifting positions P 1 to P 11 .

In this embodiment, the single shifting distances SD 1 to SD 10 are equal to each other. However, at least one of the single shifting distances SD 1 to SD 10 can be different from another of the single shifting distances SD 1 to SD 10 .

In this embodiment, the single shifting distance SD is smaller than 4.8 mm. The single shifting distance SD is smaller than 4.5 mm. The single shifting distance SD is smaller than 4.2 mm. The single shifting distance SD is larger than 3.5 mm. In this embodiment, the single shifting distance SD is 4.1 mm. However, the single shifting distance SD is not limited to this embodiment and the above ranges.

The bicycle sprocket assembly SP includes first to eleventh sprockets SP 1 to SP 11 . The shifting positions P 1 to P 11 respectively correspond to the first to eleventh sprockets SP 1 to SP 11 . The chain guide 16 is moved in accordance with the shifting positions P 1 to P 11 . For example, the shifting positions P 1 to P 11 are defined as target axial positions of the chain guide 16 in the pulley axial direction D 1 . Thus, an actual axial position of the chain guide 16 can be offset from one of shifting positions P 1 to P 11 due to a manufacturing error and/or an assembly error of the bicycle derailleur 10 . The shifting positions P 1 to P 11 can also defined as target positions of the movable member 14 . the are not actual axial positions of the chain guide 16 in the pulley axial direction D 1 . For example, the bicycle chain C is engaged with the first sprocket SP 1 in a state where the chain guide 16 is in the shifting position P 1 . The bicycle chain C is shifted from the first sprocket SP 1 to the second sprocket SP 2 when the chain guide 16 is moved from the shifting position P 1 to the shifting position P 2 . The shifting positions P 1 to P 11 can also be referred to as first to eleventh shifting positions P 1 to P 11 , respectively. A total number of the sprockets of the bicycle sprocket assembly SP is not limited to this embodiment.

As seen in FIG. 3 , the bicycle derailleur 10 comprises a biasing member 39 . The biasing member 39 is mounted to the linkage structure 20 . The chain guide 16 is held in one of the shifting positions P 1 to P 11 by the inner wire MC 1 of the mechanical cable MC and a biasing force of the biasing member 39 .

The chain guide 16 comprises an inner guide plate 40 , an outer guide plate 42 , at least one pulley axle 44 , and at least one pulley 46 . The at least one pulley axle 44 is configured to be coupled to the inner guide plate 40 and the outer guide plate 42 . The at least one pulley 46 is configured to be rotatably supported around the at least one pulley axle 44 . The at least one pulley 46 is rotatable relative to the inner guide plate 40 and the outer guide plate 42 about a rotational center axis A 2 .

In this embodiment, the at least one pulley axle 44 includes a guide-pulley axle 48 and a tension-pulley axle 50 . The guide-pulley axle 48 is coupled to the inner guide plate 40 and the outer guide plate 42 . The tension-pulley axle 50 is coupled to the inner guide plate 40 and the outer guide plate 42 . The guide-pulley axle 48 defines a rotational center axis A 21 . The tension-pulley axle 50 defines a rotational center axis A 22 . The at least one pulley 46 includes a guide pulley 52 and a tension pulley 54 . The guide pulley 52 is configured to be rotatably supported around the guide-pulley axle 48 . The tension pulley 54 is configured to be rotatably supported around the tension-pulley axle 50 . The guide pulley 52 is closer to the pivot axis PA of the movable member 14 than the tension pulley 54 . The guide pulley 52 is rotatable relative to the inner guide plate 40 and the outer guide plate 42 about the rotational center axis A 21 . The tension pulley 54 is rotatable relative to the inner guide plate 40 and the outer guide plate 42 about the rotational center axis A 22 . In this embodiment, the rotational center axis A 21 is coincident with the pivot axis PA. However, the rotational center axis A 21 can be offset from the pivot axis PA. As seen in FIG. 1 , the guide pulley 52 is closer to the rotational axis A 1 of the bicycle sprocket assembly SP than the tension pulley 54 in a state where the bicycle derailleur 10 is mounted to the bicycle frame BF.

As seen in FIG. 3 , the at least one pulley 46 includes a pulley body 56 and a plurality of pulley teeth 58 extending radially outwardly from the pulley body 56 with respect to the rotational center axis A 2 . In this embodiment, the guide pulley 52 includes a guide-pulley body 52 A and a plurality of guide-pulley teeth 52 B extending radially outwardly from the guide-pulley body 52 A with respect to the rotational center axis A 21 . The tension pulley 54 includes a tension-pulley body 54 A and a plurality of tension-pulley teeth 54 B extending radially outwardly from the tension-pulley body 54 A with respect to the rotational center axis A 22 . The pulley tooth 58 (the guide-pulley tooth 52 B, the tension-pulley tooth 54 B) is configured to engage with the bicycle chain C.

As seen in FIG. 4 , the bicycle chain C includes pairs of opposed inner link plates C 1 , pairs of opposed outer link plates C 2 , a plurality of rollers C 3 , and a plurality of pins C 4 . The roller C 3 is provided between the opposed inner link plates C 1 . The pin C 4 pivotally couples the opposed inner link plates C 1 to the opposed outer link plates C 2 . An inner link space C 11 is defined between the opposed inner link plates C 1 . An outer link space C 21 is defined between the opposed outer link plates C 2 .

The inner link plate C 1 includes a recess C 1 R provided on an inner surface C 1 S of the inner link plate C 1 . The inner link plate C 1 includes a first end portion C 12 and a second end portion C 13 . The first end portion C 12 is contactable with the roller C 3 . The second end portion C 13 is contactable with the roller C 3 . The inner link space C 11 has an axial width WC 11 which is larger than an axial distance WC 12 between the opposed first end portions C 12 of the inner link plates C 1 and larger than an axial distance WC 13 between the opposed second end portions C 13 of the inner link plates C 1 .

As seen in FIG. 5 , the guide-pulley tooth 52 B has a chain-engaging axial width W 1 defined in the pulley axial direction D 1 with respect to the rotational center axis A 21 . The guide-pulley tooth 52 B includes a first axial surface 52 C and a second axial surface 52 D. The first axial surface 52 C at least partially faces in the pulley axial direction D 1 to be engageable with one of the inner link plate C 1 and the outer link plate C 2 of the bicycle chain C. The second axial surface 52 D at least partially faces in the pulley axial direction D 1 to be engageable with one of another inner link plate C 1 and another outer link plate C 2 of the bicycle chain C. The second axial surface 52 D is provided on a reverse side of the first axial surface 52 C in the pulley axial direction D 1 . The chain-engaging axial width W 1 is defined from the first axial surface 52 C to the second axial surface 52 D in the pulley axial direction D 1 . The guide pulley 52 has an axial center plane CP 1 defined to bisect the chain-engaging axial width W 1 . The axial center plane CP 1 is perpendicular to the rotational center axis A 21 .

The chain-engaging axial width W 1 is smaller than the axial width WC 11 of the inner link space C 11 defined between the opposed inner link plates C 1 . The chain-engaging axial width W 1 is smaller than an axial width WC 21 of the outer link space C 21 defined between the opposed outer link plates C 2 .

As seen in FIG. 6 , the tension-pulley tooth 54 B has a chain-engaging axial width W 2 defined in the pulley axial direction D 1 with respect to the rotational center axis A 22 . The tension-pulley tooth 54 B includes a first axial surface 54 C and a second axial surface 54 D. The first axial surface 54 C at least partially faces in the pulley axial direction D 1 to be engageable with one of the inner link plate C 1 and the outer link plate C 2 of the bicycle chain C. The second axial surface 54 D at least partially faces in the pulley axial direction D 1 to be engageable with one of another inner link plate C 1 and another outer link plate C 2 of the bicycle chain C. The second axial surface 54 D is provided on a reverse side of the first axial surface 54 C in the pulley axial direction D 1 . The chain-engaging axial width W 2 is defined from the first axial surface 54 C to the second axial surface MD in the pulley axial direction D 1 . The tension pulley 54 has an axial center plane CP 2 defined to bisect the chain-engaging axial width W 2 . The axial center plane CP 2 is perpendicular to the rotational center axis A 22 .

The chain-engaging axial width W 2 is smaller than the axial width WC 11 of the inner link space C 11 defined between the opposed inner link plates C 1 . The chain-engaging axial width W 1 is smaller than the axial width WC 21 of the outer link space C 21 defined between the opposed outer link plates C 2 .

As seen in FIG. 2 , the inner guide plate 40 is spaced apart from the outer guide plate 42 in the pulley axial direction D 1 . The at least one pulley 46 is provided between the inner guide plate 40 and the outer guide plate 42 in the pulley axial direction D 1 . In this embodiment, the guide pulley 52 and the tension pulley 54 are provided between the inner guide plate 40 and the outer guide plate 42 in the pulley axial direction D 1 .

As seen in FIGS. 7 and 8 , the at least one pulley 46 is configured to be movable between the inner guide plate 40 and the outer guide plate 42 within a maximum pulley movable amount MA 1 or MA 2 in the pulley axial direction D 1 with respect to the rotational center axis A 2 of the at least one pulley 46 .

As seen in FIG. 7 , the guide pulley 52 is configured to be movable between the inner guide plate 40 and the outer guide plate 42 within the maximum pulley movable amount MA 1 in the pulley axial direction D 1 . The maximum pulley movable amount MA 1 is defined as a distance between a position where the guide pulley 52 is in contact with the inner guide plate 40 and a position where the guide pulley 52 is in contact with the outer guide plate 42 . A ratio of the maximum pulley movable amount MA 1 to the single shifting distance SD ranges from 0.21 to 0.35. The ratio of the maximum pulley movable amount MA 1 to the single shifting distance SD ranges from 0.24 to 0.30. However, the ratio of the maximum pulley movable amount MA 1 to the single shifting distance SD is not limited to this embodiment and the above ranges.

The maximum pulley movable amount MA 1 is larger than 0.8 mm. The maximum pulley movable amount MA 1 is larger than 0.9 mm. The maximum pulley movable amount MA 1 is smaller than 1.5 mm. The maximum pulley movable amount MA 1 is preferably larger than 1 mm. The maximum pulley movable amount MA 1 is preferably smaller than 1.2 mm. However, the maximum pulley movable amount MA 1 is not limited to this embodiment and the above ranges.

In this embodiment, the bicycle derailleur 10 comprises a guide-pulley bush 48 A provided between the guide pulley 52 and the guide-pulley axle 48 to support the guide pulley 52 rotatably and slidably relative to the guide-pulley axle 48 . The guide-pulley body 52 A includes a hole 52 H. The guide-pulley axle 48 and the guide-pulley bush 48 A extend through the hole 52 H. However, the guide-pulley bush 48 A can be omitted from the bicycle derailleur 10 or can be replaced with other structures such as a bearing. The guide-pulley axle 48 pivotally couples the chain guide 16 to the movable member 14 about the pivot axis PA.

In this embodiment, the guide-pulley body 52 A and the plurality of guide-pulley teeth 52 B are movable relative to the inner guide plate 40 and the outer guide plate 42 within the maximum pulley movable amount MA 1 in the pulley axial direction D 1 . However, only the plurality of guide-pulley teeth 52 B can be configured to be movable relative to the inner guide plate 40 and the outer guide plate 42 within the maximum pulley movable amount MA 1 in the pulley axial direction D 1 .

As seen in FIG. 8 , the tension pulley 54 is configured to be movable between the inner guide plate 40 and the outer guide plate 42 within the maximum pulley movable amount MA 2 in the pulley axial direction D 1 . The maximum pulley movable amount MA 2 is defined as a distance between a position where the tension pulley 54 is in contact with the inner guide plate 40 and a position where the tension pulley 54 is in contact with the outer guide plate 42 . A ratio of the maximum pulley movable amount MA 2 to the single shifting distance SD ranges from 0.21 to 0.35. The ratio of the maximum pulley movable amount MA 2 to the single shifting distance SD ranges from 0.24 to 0.30. However, the ratio of the maximum pulley movable amount MA 2 to the single shifting distance SD is not limited to this embodiment and the above ranges.

The maximum pulley movable amount MA 2 is larger than 0.8 mm. The maximum pulley movable amount MA 2 is larger than 0.9 mm. The maximum pulley movable amount MA 2 is smaller than 1.5 mm. The maximum pulley movable amount MA 2 is preferably larger than 1 mm. The maximum pulley movable amount MA 2 is preferably smaller than 1.2 mm. However, the maximum pulley movable amount MA 2 is not limited to this embodiment and the above ranges.

With the bicycle derailleur 10 , a position of the at least one pulley 46 can be automatically and effectively adjusted in the pulley axial direction D 1 when an actual position of the chain guide 16 is offset from the shifting position in the pulley axial direction D 1 . Thus, it is possible to absorb error of the position of the chain guide 16 , improving a shifting operation of the bicycle chain C. Furthermore, the position of the at least one pulley 46 can be automatically and effectively adjusted in the pulley axial direction D 1 when the chain guide 16 is moved from a current shifting position to an adjacent shifting position to shift the bicycle chain C from a current sprocket to an adjacent sprocket. This can smooth the movement of the bicycle chain C from the current sprocket to the adjacent sprocket during the shifting operation.

In this embodiment, the bicycle derailleur 10 comprises a tension-pulley bush 50 A provided between the tension pulley 54 and the tension-pulley axle 50 to support the tension pulley 54 rotatably and slidably relative to the tension-pulley axle 50 . The tension-pulley body 54 A includes a hole 54 H. The tension-pulley axle 50 and the tension-pulley bush 50 A extend through the hole 54 H. However, the tension-pulley bush 50 A can be omitted from the bicycle derailleur 10 or can be replaced with other structures such as a bearing.

In this embodiment, the tension-pulley body 54 A and the plurality of tension-pulley teeth 54 B are movable relative to the inner guide plate 40 and the outer guide plate 42 within the maximum pulley movable amount MA 2 in the pulley axial direction D 1 . However, only the plurality of tension-pulley teeth 54 B can be configured to be movable relative to the inner guide plate 40 and the outer guide plate 42 within the maximum pulley movable amount MA 2 in the pulley axial direction D 1 .

First Modification

In the above embodiment, the at least one pulley axle 44 includes the guide-pulley axle 48 and the tension-pulley axle 50 . The at least one pulley 46 includes the guide pulley 52 and the tension pulley 54 . As seen in FIG. 9 , however, the at least one pulley axle 44 can further include an additional pulley axle 60 . The at least one pulley 46 can further include an additional pulley 62 configured to be rotatably supported around the additional pulley axle 60 . The additional pulley 62 can be configured to be movable between the inner guide plate 40 and the outer guide plate 42 within a maximum pulley movable amount in the pulley axial direction D 1 .

Second Modification

In the above embodiment and the first modification, the chain-engaging axial widths W 1 of the guide-pulley teeth 52 B are equal to each other. The chain-engaging axial widths W 2 of the tension-pulley teeth 54 B are equal to each other. However, at least one of the guide-pulley teeth 52 B can has the chain-engaging axial width W 1 different from the chain-engaging axial width W 1 of another of the guide-pulley teeth 52 B. At least one of the tension-pulley teeth 54 B can has the chain-engaging axial width different W 2 from the chain-engaging axial width W 2 of another of the tension-pulley teeth 54 B.

As seen in FIG. 10 , for example, the plurality of pulley teeth 58 can include at least one first pulley tooth 64 and at least one second pulley tooth 66 . The plurality of pulley teeth 58 can include a plurality of first pulley teeth 64 and a plurality of second pulley teeth 66 . The first pulley teeth 64 and the second pulley teeth 66 are circumferentially alternately arranged. The at least one first pulley tooth 64 radially outwardly from the pulley body 56 . The at least one second pulley tooth 66 radially outwardly from the pulley body 56 .

As seen in FIG. 11 , for example, the at least one first pulley tooth 64 is configured to engage with the pair of opposed outer link plates C 2 of the bicycle chain C. The at least one first pulley tooth 64 has a first chain-engaging axial width W 11 defined in the pulley axial direction D 1 . The first pulley tooth 64 includes a first axial surface 60 C and a second axial surface 60 D. The first axial surface 60 C faces in the pulley axial direction D 1 to be engageable with one of the opposed outer link plates C 2 of the bicycle chain C The second axial surface 60 D faces in the pulley axial direction D 1 to be engageable with the other of the opposed outer link plates C 2 of the bicycle chain C. The second axial surface 60 D is provided on a reverse side of the first axial surface 60 C in the pulley axial direction D 1 . The first chain-engaging axial width W 11 is defined from the first axial surface 60 C to the second axial surface 60 D in the pulley axial direction D 1 .

As seen in FIG. 12 , for example, the at least one second pulley tooth 66 is configured to engage with a pair of opposed inner link plates C 5 of the bicycle chain C. The at least one second pulley tooth 66 has a second chain-engaging axial width W 21 that is smaller than the first chain-engaging axial width W 11 . The second chain-engaging axial width W 21 is defined in the pulley axial direction D 1 . The second pulley tooth 66 includes a second axial surface 62 C and a second axial surface 62 D. The second axial surface 62 C faces in the pulley axial direction D 1 to be engageable with one of the opposed inner link plates C 5 of the bicycle chain C. The second axial surface 62 D faces in the pulley axial direction D 1 to be engageable with the other of the opposed inner link plates C 5 of the bicycle chain C. The second axial surface 62 D is provided on a reverse side of the second axial surface 62 C in the pulley axial direction D 1 . The second chain-engaging axial width W 21 is defined from the second axial surface 62 C to the second axial surface 62 D in the pulley axial direction D 1 . The second chain-engaging axial width W 21 is smaller than an axial width WC 51 of the inner link space C 51 defined between the opposed inner link plates C 5 . The first chain-engaging axial width W 11 is larger than the axial width WC 51 of the inner link space C 51 .

As seen in FIG. 13 , the inner link plate C 5 has a shape different from a shape of the inner link plate C 1 illustrated in FIG. 4 . The recess C 1 R is omitted from the inner link plate C 5 . However, the inner link plate C 5 can have the same shape as that of the inner link plate C 1 .

Other Modifications

In the above embodiment and the first and second modification, the shifting positions P 1 to P 11 are defined based on the chain guide 16 . However, the shifting positions P 1 to P 11 can be defined based on other members such as the movable member 14 .

In the above embodiment and the modifications, an actuation ratio of an amount of operation of the operating device 2 (e.g., an amount of movement of the inner wire MC 1 relative to the outer casing MC 2 ) to an amount of movement of the chain guide 16 is equal to or lower than 1.5. The actuation ratio of the amount of operation of the operating device 2 to an amount of movement of the chain guide 16 is preferably equal to or lower than 1.1. However, the actuation ratio is not limited to the above embodiment and the modifications.

In the above embodiment and the modifications, the guide pulley 52 and the tension pulley 54 are movable relative to the inner guide plate 40 and the outer guide plate 42 within the maximum pulley movable amount in the pulley axial direction D 1 . However, one of the guide pulley 52 and the tension pulley 54 can be configured to be non-movable relative to the inner guide plate 40 and the outer guide plate 42 in the pulley axial direction D 1 or movable relative to the inner guide plate 40 and the outer guide plate 42 in the pulley axial direction D 1 within a movable amount smaller than the maximum pulley movable amount.

In the above embodiment and the modifications, the bicycle derailleur 10 is configured to be connected to the operating device 2 with the mechanical cable MC. However, the bicycle derailleur 10 can be configured to be connected to the operating device 2 with an electrical cable or wireless communication path. In such embodiments, for example, the bicycle derailleur 10 comprises an electric actuator configured to move the movable member 14 and/or the chain guide 16 in response to a signal generated in the operating device 2 . The bicycle derailleur 10 can comprise a position sensor configured to sense a position of the movable member 14 or the chain guide 16 as a current shifting position of the bicycle derailleur 10 . The bicycle derailleur 10 can comprise a wireless communicator configured to wirelessly communicate with the operating device 2 . The actuator is connected to the wireless communicator to move the chain guide relative to the base member in response to a wireless signal received by the wireless communicator from the operating device 2 . The bicycle derailleur 10 can comprises a power supply connected to the actuator and the wireless communicator to supply electric power to the actuator and the wireless communicator. The actuator can be mounted to one of the base member 12 , the movable member 14 , the chain guide 16 , and the linkage structure 20 . The wireless communicator can be mounted to one of the base member 12 , the movable member 14 , the chain guide 16 , and the linkage structure 20 . The power supply can be mounted to one of the base member 12 , the movable member 14 , the chain guide 16 , and the linkage structure 20 .

The term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. This concept also applies to words of similar meaning, for example, the terms “have,” “include” and their derivatives.

The terms “member,” “section,” “portion,” “part,” “element,” “body” and “structure” when used in the singular can have the dual meaning of a single part or a plurality of parts.

The ordinal numbers such as “first” and “second” recited in the present application are merely identifiers, but do not have any other meanings, for example, a particular order and the like. Moreover, for example, the term “first element” itself does not imply an existence of “second element,” and the term “second element” itself does not imply an existence of “first element.”

The term “pair of,” as used herein, can encompass the configuration in which the pair of elements have different shapes or structures from each other in addition to the configuration in which the pair of elements have the same shapes or structures as each other.

The terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein.

Finally, terms of degree such as “substantially,” “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. All of numerical values described in the present application can be construed as including the terms such as “substantially,” “about” and “approximately.”

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.