Electrically operated derailleur with power storing mechanism
A rear derailleur for a bicycle includes a base member for attaching the rear derailleur to the bicycle, a movable member for supporting a chain guide, and a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member. An electrically operated actuating member is operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward a rear wheel of the bicycle, and moving the actuating member in a second direction causes the movable member to move laterally away from the rear wheel of the bicycle. A power storing mechanism is disposed in a power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member.
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The present invention is directed to bicycles and, more particularly, to various features of an electrically operated bicycle derailleur.
Derailleur operated bicycle transmissions typically comprise a plurality of sprockets that rotate with another rotating member (e.g., the front crank and/or the rear wheel of the bicycle) and a derailleur that is used to shift a chain among the plurality of sprockets. Conventional derailleurs comprise a base member adapted to be mounted to the bicycle frame, a movable member supporting a chain guide, and a linkage mechanism coupled between the base member and the movable member so that the movable member can move laterally inwardly and outwardly relative to the base member. Such derailleurs are manually controlled by a hand operated actuator such as a lever or twist-grip attached to the bicycle handlebar, wherein the derailleur is connected to the actuator by a bowden cable.
Recently, various electronic devices have been used to control the movement of the derailleur. Such devices sometimes comprise a traveling condition detector for detecting a traveling condition of the bicycle, a motor for moving the derailleur laterally inwardly and outwardly relative to the plurality of sprockets, and a processor. The processor controls the motor in response to the detected traveling condition so that the derailleur is in the proper position to maintain the traveling condition within a desired range.
The motor used to move the derailleur typically moves the derailleur laterally inwardly and/or laterally outwardly by moving an actuating member such as an actuating arm or a pivot shaft attached to the linkage mechanism. Unfortunately, sometimes the movable member experiences significant resistance to lateral movement, especially when the plurality of sprockets are stationary, and this resistance is communicated to the actuating member. Since the motor may be unable to move the actuating member in such a situation, there is a risk of damage to the motor. Another problem is that an external force may be applied to the movable member such as a force directed toward the wheel when the bicycle lays or falls down, or a force directed away from the wheel if the derailleur catches some external object. Such external forces also may be communicated to the actuating member, thus again risking damage to the motor.
SUMMARY OF THE INVENTIONThe present invention is directed to various features of an electrically operated bicycle derailleur. In one embodiment of the present invention, a derailleur for a bicycle includes a base member for attaching the derailleur to the bicycle, a movable member for supporting a chain guide, and a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member. An electrically operated actuating member is operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward the bicycle, and moving the actuating member in a second direction causes the movable member to move laterally away from the bicycle. A power storing mechanism is disposed in a power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member. Additional inventive features will become apparent from the description below, and such features alone or in combination with the above features may form the basis of further inventions as recited in the claims and their equivalents.
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Rear derailleur 66 further comprises a linkage mechanism in the form of link members 440 and 444 pivotably coupled to rear derailleur control housing 315 through respective pivot shafts 448 and 452. The other ends of link members 440 and 444 are pivotably coupled to a movable member 456 through respective pivot shafts 460 and 462. Movable member 456 rotatably supports a chain guide 466 which, in turn, rotatably supports a guide pulley 470 and a tension pulley 474 for engaging chain 58 in a known manner. As discussed in more detail below, a motor 480 (
Link member 444 includes a first link plate 640 and a second link plate 644. First link plate 644 has a generally U-shape formed by an upper wall 648, a side wall 652 and a bottom wall 656, wherein bottom wall 656 is fastened to second link plate 644 through rivets 657. Generally circular openings 658 and 659 are formed on one end of upper wall 648 of first link plate 640 and on one end of second link plate 644, wherein circular openings 658 and 659 receive pivot shaft 452 therethrough such that first link plate 640 and second link plate 644 can rotate around pivot shaft 452. Similarly, respective openings 653 and 654 are formed on the opposite ends of upper wall 648 and lower wall 656 of first link plate 640, and another opening 655 is formed on the opposite end of second link plate 644, wherein openings 653, 654 and 655 receive pivot shaft 462 therethrough. An arcuate slot 662 forming link member abutments 663 and 664 is formed in close proximity to opening 658 in upper wall 648 for reasons discussed below.
A spring hooking member 666 is disposed at an intermediate portion of second link plate 644 for retaining a second end 668 of spring 632. Spring 632 functions to take up the play in the gear reduction mechanism in rear derailleur control housing 315. A spring shaft 680 extends through respective openings 684 and 688 in upper wall 648 and bottom wall 656 of first link plate 640, through upper and lower bushings 692 and 696, and through the coiled section 700 of a coil spring 704 disposed between bushings 692 and 696. Coil spring 704 has a first end 732 and a second end 734, wherein the second end 734 of spring 704 abuts against pivot shaft 462. A first end 708 of an elongated leaf spring 712 is fastened to the outer side of side wall 652 of first link plate 640 through a rivet 717. In this embodiment, the spring constant of spring 712 is greater than the spring constant of spring 704, and the spring constant of spring 704 is greater than the spring constant of spring 632. That is because, in this embodiment, spring 712 is used to store power when movable member 456 moves in the downshifting direction (wherein normal resistance already is significant), spring 704 is used to store power when movable member 456 moves in the upshifting direction (wherein normal resistance already is relatively small, and spring 632 merely takes up the play in the gear reduction mechanism in rear derailleur control housing 315.
An actuating arm 716 has an opening 720 formed on a proximal end thereof for receiving pivot shaft 452 therethrough. Opening 720 includes a flat 724 for engaging flat 453 on pivot shaft 452 so that actuating arm 716 is nonrotatably fixed relative to pivot shaft 452. A first spring abutment 728 in the form of a post projects downwardly from a distal end of actuating arm 716 for abutting against first end 732 of spring 704, and a second spring abutment 733 is disposed at the distal end of actuating arm 716 for abutting against a second end 735 of leaf spring 712. An actuating member abutment in the form of a motion limiting post 736 extends upwardly from actuating arm 716 into slot 662 in upper wall 648 of first link pate 444 when derailleur 66 is in the assembled state.
While the above is a description of various embodiments of inventive features, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the gear mechanism within rear derailleur housing may be omitted, and motor 480 may operate actuating arm 716 through a cable. The teachings herein may be applied to a front derailleur. The springs 704 and 712 need not be coil springs or leaf springs, and they may constitute any number of biasing elements.
The size, shape, location or orientation of the various components may be changed as desired. Components that are shown directly connected or contacting each other may have intermediate structures disposed between them. The functions of one element may be performed by two, and vice versa. The structures and functions of one embodiment may be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the scope of the invention should not be limited by the specific structures disclosed or the apparent initial focus on a particular structure or feature.
Claims
1. A derailleur for a bicycle comprising:
- a base member for attaching the derailleur to the bicycle;
- a movable member for supporting a chain guide;
- a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member;
- wherein the linkage mechanism is moved by rotating a pivot shaft;
- an electrically operated actuating member operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward the bicycle and moving the actuating member in a second direction causes the movable member to move laterally away from the bicycle; and
- a power storing mechanism disposed in a first power transmission path and in a different second power transmission path between the actuating member and the movable member for storing forces directed from the actuating member toward the movable member in a first force direction along the first power transmission path and from the actuating member toward the movable member in a second force direction along the second power transmission path, wherein the first force direction is different from the second force direction;
- wherein the power storing mechanism is disposed in at least one of the first power transmission path or the second power transmission path downstream of the pivot shaft from the pivot shaft toward the movable member when the pivot shaft is rotated.
2. The derailleur according to claim 1 wherein the power storing mechanism comprises a biasing element disposed in the first power transmission path between the actuating member and the movable member for storing motive power of the actuating member in the first force direction.
3. The derailleur according to claim 1 wherein the power storing mechanism comprises a biasing element disposed in the second power transmission path between the actuating member and the movable member for storing motive power of the actuating member in the second force direction.
4. The derailleur according to claim 1 wherein the linkage mechanism comprises a link member having a first end coupled to one of the base member and the movable member and a second end coupled to the other one of the base member and the movable member.
5. The derailleur according to claim 4 wherein the first end of the link member is rotatably coupled to the one of the base member and the movable member.
6. A derailleur for a bicycle comprising:
- a base member for attaching the derailleur to the bicycle;
- a movable member for supporting a chain guide;
- a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member;
- wherein the linkage mechanism is moved by rotating a pivot shaft;
- an electrically operated actuating member operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward the bicycle and moving the actuating member in a second direction causes the movable member to move laterally away from the bicycle; and
- a power storing mechanism disposed in a first power transmission path and in a different second power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member, wherein the power storing mechanism comprises: a first biasing element disposed in the first power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member; and a second biasing element disposed in the second power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member; wherein the first biasing element is disposed in the first power transmission path downstream of the pivot shaft from the pivot shaft toward the movable member when the pivot shaft is rotated.
7. The derailleur according to claim 6 wherein the actuating member is disposed between the first biasing element and the second biasing element.
8. A derailleur for a bicycle comprising:
- a base member for attaching the derailleur to the bicycle;
- a movable member for supporting a chain guide;
- a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member;
- wherein the linkage mechanism comprises a link member having a first end rotatably coupled to one of the base member and the movable member and a second end coupled to the other one of the base member and the movable member;
- an electrically operated actuating member operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward the bicycle and moving the actuating member in a second direction causes the movable member to move laterally away from the bicycle; and
- a power storing mechanism disposed in a first power transmission path and in a different second power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member, wherein the power storing mechanism comprises: a first biasing element disposed in the first power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member; and a second biasing element disposed in the second power transmission path between the actuating member and the movable member for storing relative forces applied between the actuating member and the movable member; wherein the first biasing element comprises a first spring having a first portion that engages the link member and a second portion that engages the actuating member; and wherein the second biasing element comprises a second spring having a first portion that engages the link member and a second portion that engages the actuating member.
9. The derailleur according to claim 8 wherein the actuating member is disposed between the first biasing element and the second biasing element.
10. The derailleur according to claim 9 wherein the first biasing element comprises a first spring having a first end that engages the link member and a second end that engages the actuating member, and wherein the second biasing element comprises a second spring having a first end that engages the link member and a second end that engages the actuating member.
11. The derailleur according to claim 10 8 wherein the actuating member has a first end that rotates coaxially with the first end of the link member.
12. The derailleur according to claim 11 wherein the actuating member has a second end disposed between the second end of the first spring and the second end of the second spring.
13. The derailleur according to claim 12 wherein the first spring has a different spring constant than the second spring.
14. The derailleur according to claim 12 wherein at least one of the first spring and the second spring comprises a leaf spring.
15. The derailleur according to claim 12 wherein at least one of the first spring and the second spring comprises a coil spring.
16. The derailleur according to claim 15 wherein the coil spring has a coiled section that coils around a projection extending from the link member.
17. The derailleur according to claim 12 wherein the actuating member has an actuating member abutment, wherein the link member has a link member abutment, and wherein the actuating member abutment is spaced apart from the link member abutment when the actuating member is in a neutral position relative to the link member.
18. The derailleur according to claim 17 wherein the actuating member abutment contacts the link member abutment when the actuating member is in a selected rotational position relative to the link member.
19. The derailleur according to claim 12 wherein one of the actuating member and the link member has a first abutment, wherein the other one of the actuating member and the link member has a second abutment spaced apart from a third abutment, and wherein the first abutment is spaced apart from the second abutment and the third abutment when the actuating member is in a neutral position relative to the link member.
20. The derailleur according to claim 19 wherein the first abutment contacts the second abutment when the actuating member is in a first selected rotational position relative to the link member in the first direction, and wherein the first abutment contacts the third abutment when the actuating member is in a second selected rotational position relative to the link member in the second direction.
21. A derailleur for a bicycle comprising:
- a base member for attaching the derailleur to the bicycle;
- a movable member for supporting a chain guide;
- a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member;
- wherein the linkage mechanism is moved by rotating a pivot shaft;
- an electrically operated actuating member operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward the bicycle and moving the actuating member in a second direction causes the movable member to move laterally away from the bicycle; and
- a power storing mechanism disposed in a first power transmission path and in a different second power transmission path between the actuating member and the movable member for storing forces directed from the movable member toward the actuating member in a first force direction and from the movable member toward the actuating member in a second force direction, wherein the first force direction is different from the second force direction;
- wherein the power storing mechanism is disposed in at least one of the first power transmission path or the second power transmission path downstream of the pivot shaft from the pivot shaft toward the movable member when the pivot shaft is rotated.
22. A rear derailleur apparatus for a bicycle comprising:
- a base member for attaching the rear derailleur to the bicycle;
- a movable member for supporting a chain guide;
- a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member;
- wherein the linkage mechanism is moved by rotating a pivot shaft;
- an actuating member operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward a rear wheel of the bicycle and moving the actuating member in a second direction causes the movable member to move laterally away from the rear wheel of the bicycle;
- a motor that electrically drives the actuating member in the first direction and the second direction; and
- a power storing mechanism disposed in a first power transmission path and in a different second power transmission path between the actuating member and the movable member for storing forces directed from the actuating member toward the movable member in a first force direction and from the actuating member toward the movable member in a second force direction, wherein the first force direction is different from the second force direction;
- wherein the power storing mechanism is disposed in at least one of the first power transmission path or the second power transmission path downstream of the pivot shaft from the pivot shaft toward the movable member when the pivot shaft is rotated.
23. A rear derailleur apparatus for a bicycle comprising:
- a base member for attaching the rear derailleur to the bicycle;
- a movable member for supporting a chain guide;
- a linkage mechanism coupling the base member to the movable member so that the movable member is capable of movement relative to the base member;
- wherein the linkage mechanism is moved by rotating a pivot shaft;
- an actuating member operatively coupled to the linkage mechanism, wherein moving the actuating member in a first direction causes the movable member to move laterally toward a rear wheel of the bicycle and moving the actuating member in a second direction causes the movable member to move laterally away from the rear wheel of the bicycle;
- a motor that electrically drives the actuating member in the first direction and the second direction; and
- a power storing mechanism disposed in a first power transmission path and in a different second power transmission path between the actuating member and the movable member for storing forces directed from the movable member toward the actuating member in a first force direction and from the movable member toward the actuating member in a second force direction, wherein the first force direction is different from the second force direction;
- wherein the power storing mechanism is disposed in at least one of the first power transmission path or the second power transmission path downstream of the pivot shaft from the pivot shaft toward the movable member when the pivot shaft is rotated.
24. The derailleur according to claim 6 wherein the second biasing element is disposed in the second power transmission path downstream of the pivot shaft when the pivot shaft is rotated.
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Type: Grant
Filed: Feb 18, 2008
Date of Patent: Sep 28, 2010
Assignee: Shimano, Inc. (Sakai-ku, Sakai, Osaka)
Inventor: Masahiko Fukuda (Amagasaki)
Primary Examiner: Marcus Charles
Attorney: James A. Deland
Application Number: 12/032,861
International Classification: F16H 63/04 (20060101); B62M 9/12 (20060101);