Bicycle Shifter

Abstract

A shifter for a bicycle transmission that includes a spring element that functions as a preloaded spring for cable-release operations and a detent pawl. The shifter also includes a housing having a detent contour, a cable spool for winding and unwinding a control cable thereon, and an actuator. The actuator includes a release element, a spring seat and a driver. The spring element includes a detent pawl, a base and a spool driver. The detent pawl is engageable with the detent contour to maintain the shifter in a current detent position. The base is supported by the spring seat and the spool driver is operatively engages and rotates the spool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is an exploded front perspective view of a bicycle shifter in according to one embodiment of the present invention;

FIG. 2 is an exploded rear perspective view of the bicycle shifter of FIG. 1;

FIG. 3 is a cross-sectional view of the bicycle shifter of FIG. 1 showing a spring element in a unloaded state; and

FIG. 4 is a cross-sectional view of the bicycle shifter of FIG. 1 showing the spring element preloaded and deformed.

Claims

1. A shifter for a bicycle transmission comprising: a housing including a detent contour;a cable spool for winding and unwinding a control cable thereon;an actuator including a release element, a spring seat and a driver; anda spring element including: a detent pawl engageable with the detent contour to maintain the shifter in a current detent position;a base supported by the spring seat; anda spool driver operatively engaging and rotating the spool.

2. A shifter according to claim 1, wherein the shifter is configured such that during the onset of a cable-release operation the actuator is initially displaced from a rest position to preload and reversibly deform the spring element without releasing the detent pawl from the current detent position.

3. A shifter according to claim 2, wherein upon further displacement of the actuator the release element engages the spring element to release the detent pawl from the current detent position.

4. A shifter according to claim 3, wherein the released preloaded spring element rotates the cable spool to unwind the control cable until the engagement of the detent pawl in a next detent position.

5. A shifter according to claim 4, wherein the spring element is a single piece.

6. A shifter according to claim 5, wherein the spring element is shaped from a flat strip of metal.

7. A shifter according to claim 6, wherein the spring element is configured such that when installed in the shifter there is no play between the spool, actuator and detent contour in the shifter rest position.

8. A shifter according to claim 7, wherein the spring element is configured to include an initial preload when installed in the shifter such that there is no play between the spool, actuator and detent contour in the shifter rest position.

9. A shifter according to claim 1, wherein the spring element is a single piece.

10. A shifter according to claim 9, wherein the spring element is shaped from a flat strip of metal.

11. A shifter according to claim 1, wherein the spring element is configured such that when installed in the shifter there is no play between the spool, actuator and detent contour in a rest position of the shifter.

12. A shifter according to claim 11, wherein the spring element is configured to include an initial preload installed in the shifter such that there is no play between the spool, actuator and detent contour in the shifter rest position.

13. A shifter according to claim 1, wherein the cable spool includes a first bumper to support the spring element upon installation of the spring into the cable spool.

14. A shifter according to claim 13, wherein the cable spool includes a second bumper to support the spring element under deformation.

15. A shifter according to claim 1, wherein the release element and the driver are disposed on a face of the actuator, the driver received in a mating slot on the cable spool.

16. A shifter according to claim 1, wherein the actuator is a rotatable handgrip.

17. A shifter according to claim 16, wherein the rotatable handgrip is rotatable about a central axis of a handlebar.