LOW PROFILE REAR DERAILLEUR

Abstract

A bicycle rear derailleur comprises a base member, a movable member, a linking member coupled between the base member and the movable member so that the movable member moves laterally relative to the base member, and an extension member having a movable member coupling location coupled to the movable member and a guide pulley coupling location offset forwardly of the movable member coupling location. A guide pulley is coupled to the extension member at the guide pulley coupling location for rotation around a guide pulley axis, and a tension pulley is coupled to the movable member below the guide pulley. The guide pulley and the tension pulley are not directly attached to a same member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a laterally outer view of a particular embodiment of a rear derailleur in a high speed position;

FIG. 2 is a laterally inner view of the derailleur;

FIG. 3 is a top view of the derailleur in the high speed position;

FIG. 4 is a bottom view of the derailleur in the high speed position;

FIG. 5 is a front view of the derailleur in the high speed position;

FIG. 6 is a rear view of the derailleur in the high speed position;

FIG. 7 is a side view of the derailleur in a low speed position;

FIG. 8 is a top view of the derailleur in the low speed position;

FIG. 9 is a bottom view of the derailleur in the low speed position;

FIG. 10 is a front view of the derailleur in the low speed position;

FIG. 11 is a rear view of the derailleur in the low speed position;

FIG. 12 is a laterally outer view of the rear derailleur attached to a conventional frame;

FIG. 13 is a laterally outer view of another embodiment of a rear derailleur in a position for engaging the chain with the smallest rear sprocket when the front derailleur engages the chain with the smallest front sprocket;

FIG. 14 is a laterally inner view of the derailleur;

FIG. 15 is a rear view of the derailleur in a position for engaging the chain with the smallest rear sprocket;

FIG. 16 is a view of the derailleur parallel to the pivot axes of the linking mechanism;

FIG. 17 is a view of the derailleur perpendicular to the pivot axes of the linking mechanism;

FIGS. 18A-18C are detailed outer, inner and cross sectional views of an end of a link member at the movable member;

FIG. 19 is a cross sectional view at the movable member and the guide pulley;

FIG. 20 is an oblique view of the pivot shaft shown in FIG. 19;

FIG. 21 is a laterally outer view of the rear derailleur in a position for engaging the chain with the largest rear sprocket when the front derailleur engages the chain with the smallest front sprocket;

FIG. 22 is a rear view of the derailleur in a position for engaging the chain with the largest rear sprocket when the front derailleur engages the chain with the smallest front sprocket; and

FIG. 23 is a laterally outer view of the rear derailleur in a position for engaging the chain with the largest rear sprocket when the front derailleur engages the chain with the largest front sprocket.

Claims

1. A bicycle rear derailleur comprising: a base member;a movable member;a linking member coupled between the base member and the movable member so that the movable member moves laterally relative to the base member;an extension member having a first movable member coupling location coupled to the movable member and a guide pulley coupling location offset forwardly of the first movable member coupling location;a guide pulley coupled to the extension member at the guide pulley coupling location for rotation around a guide pulley axis; anda tension pulley coupled to the movable member below the guide pulley;wherein the guide pulley and the tension pulley are not directly attached to a same member.

2. The derailleur according to claim 1 wherein the extension member is nonrotatably coupled relative to the movable member.

3. The derailleur according to claim 1 wherein the guide pulley coupling location is offset forwardly of the first movable member coupling location when a rearward bias is applied to the guide pulley.

4. The derailleur according to claim 1 wherein the guide pulley axis is located at the guide pulley coupling location.

5. The derailleur according to claim 1 wherein the guide pulley moves laterally to a plurality of shift positions corresponding to engagement of the chain with each of the plurality of rear sprockets, and wherein the extension member is coupled to the movable member so that the guide pulley coupling location is offset forwardly of the first movable member coupling location for each of the plurality of shift positions.

6. The derailleur according to claim 1 wherein the extension member is coupled to the movable member so that the guide pulley coupling location is offset forwardly of the first movable member coupling location for an entire range of lateral motion of the guide pulley.

7. The derailleur according to claim 6 wherein the extension member is coupled to the movable member so that the guide pulley coupling location is offset forwardly of the first movable member coupling location for an entire range of lateral motion of the movable member.

8. The derailleur according to claim 1 wherein the extension member faces the movable member at the first movable member coupling location.

9. The derailleur according to claim 1 further comprising a pulley link having a second movable member coupling location and a tension pulley coupling location, wherein the pulley link is coupled for rotation relative to the movable member around a pulley link axis, and wherein the tension pulley is coupled to the pulley link at the tension pulley coupling location for rotation around a tension pulley axis.

10. The derailleur according to claim 9 wherein the pulley link faces the movable member at the second movable member coupling location.

11. The derailleur according to claim 9 wherein the pulley link axis is located at the second movable member coupling location.

12. The derailleur according to claim 10 wherein the pulley link axis is disposed in close proximity to the first movable member coupling location of the extension member.

13. The derailleur according to claim 12 wherein the extension member is coupled to the movable member through an extension member shaft having an extension member shaft axis, and wherein the pulley link axis is disposed in close proximity to the extension member shaft axis.

14. The derailleur according to claim 13 wherein the pulley link axis is coaxial with the extension member shaft axis.

15. A bicycle rear derailleur comprising: a base member;a movable member supporting a chain guide;a first linking member coupled between the base member and the movable member so that the movable member moves laterally relative to the base member;wherein the first linking member rotates relative to the base member around a first axis;wherein the first linking member rotates relative to the movable member around a second axis; anda biasing member coupled to bias the movable member laterally relative to the base member, wherein the biasing member is retained at a first location outside of an outer peripheral surface of the first linking member when viewed perpendicular to at least one of the first axis or the second axis, and wherein the first linking member overlaps at least a portion of the biasing member when viewed perpendicular to the at least one of the first axis or the second axis.

16. The derailleur according to claim 15 wherein the biasing member comprises a spring.

17. The derailleur according to claim 16 wherein the spring comprises a coil spring that coils around a spring axis that extends in a direction substantially perpendicular to at least one of the first axis and the second axis.

18. The derailleur according to claim 17 wherein the coil spring has a first end retained at the first location.

19. The derailleur according to claim 18 wherein the first location is disposed at the second axis.

20. The derailleur according to claim 18 wherein the coil spring has a second end retained at a second location.

21. The derailleur according to claim 20 wherein the first location is disposed at second axis, and wherein the second location is disposed at the first axis.

22. The derailleur according to claim 15 further comprising: a second linking member coupled between the base member and the movable member so that the movable member moves laterally relative to the base member;wherein the second linking member rotates relative to the base member around a third axis; andwherein the second linking member rotates relative to the movable member around a fourth axis.

23. The derailleur according to claim 22 wherein a portion of the biasing member is sandwiched between the first linking member and the second linking member.