Bicycle sprocket

Patent metadata

Field	Value
Publication number	US-12377935-B2
Application number	US-202318502255-A
Country	US
Kind code	B2
Filing date	Nov 6, 2023
Priority date	Nov 30, 2020
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A bicycle sprocket for a sprocket cassette comprises a sprocket main body which extends about a virtual sprocket axis about which the sprocket is rotatable during intended operation on a bicycle. In the case of a single release tooth being formed, a release-side stabilizing tooth is arranged in the circumferential region of extent of an upshift recess formation. The release-side stabilizing tooth has an inner tooth contact surface which has a greater axial spacing to an axial reference position than an inner tooth contact surface of the reference tooth. Additionally, or alternatively, in the case of a single catch tooth being formed, a receiving-side stabilizing tooth is arranged in the circumferential region of extent of a downshift recess formation. The receiving-side stabilizing tooth has an inner tooth contact surface which has a greater axial spacing to the axial reference position than the inner tooth contact surface of the reference tooth.

First claim

What is claimed is:

1. A bicycle sprocket cassette for a bicycle drive system with a rear derailleur and a bicycle roller chain, the bicycle sprocket cassette comprising:
a plurality of coaxial sprockets each having a different number of teeth, the plurality of coaxial sprockets each having a sprocket main body with sprocket teeth arranged thereon, wherein at least one sprocket of the plurality of coaxial sprockets has, in its outboard-side end face along a section of its circumference in the region of the sprocket main body and of the sprocket teeth, at least one upshift region with an axial upshift recess formation and/or at least one downshift region with an axial downshift recess formation to allow smooth shifting operation,
wherein axial sprocket spacings are defined between each pair of adjacent sprockets of the plurality of coaxial sprockets between an outboard-side tooth contact surface of a chain inner link plate sprocket tooth situated outside the recess formations of a sprocket of the plurality of coaxial sprockets and an outboard-side tooth contact surface of a chain inner link plate sprocket tooth situated outside the recess formations of an axially adjacent sprocket to the sprocket,
wherein an axial value plot of the axial sprocket spacings of the plurality of coaxial sprockets, starting inboard with an axial sprocket spacing between a largest sprocket of the plurality of coaxial sprockets and a second largest sprocket of the plurality of coaxial sprockets and ending outboard with an axial sprocket spacing between a second smallest sprocket of the plurality of coaxial sprockets and a smallest sprocket of the plurality of coaxial sprockets is defined, and
wherein the axial value plot of the axial sprocket spacings increases overall from its inboard-side start and reaches a local maximum value in an axially middle third of an overall width of the bicycle sprocket cassette, and that the axial value plot decreases overall from the local maximum value to a local minimum value in an axially outboard-side third of the overall width of the bicycle sprocket cassette.

2. The bicycle sprocket cassette of claim 1 , wherein the axial value plot of the sprocket spacings reaches the local maximum value in the axial region of a transition sprocket assembly.

3. The bicycle sprocket cassette of claim 2 , wherein the transition sprocket assembly comprises an odd-toothed transition sprocket.

4. The bicycle sprocket cassette of claim 3 , wherein the odd-toothed transition sprocket is a sixth sprocket as counted from outboard most sprocket.

5. The bicycle sprocket cassette of claim 1 wherein the axial value plot of the sprocket spacings reaches the local maximum value in the axial region of a sixth sprocket as counted from outboard most sprocket.

6. The bicycle sprocket cassette of claim 1 , wherein the local maximum value of the axial value plot is situated between the sixth and seventh sprocket as counted from outboard most sprocket, wherein a sum of the sprocket spacings from the smallest sprocket to the seventh sprocket is between 54.5% to 55.9% of the sum of the sprocket spacings of all sprockets of the bicycle sprocket cassette.

7. The bicycle sprocket cassette of claim 6 , wherein the sum of the sprocket spacings from the smallest sprocket to the seventh sprocket is 55.2% of the sum of the sprocket spacings of all sprockets of the bicycle sprocket cassette.

8. The bicycle sprocket cassette of claim 1 wherein the axial value plot of the sprocket spacings reaches the local minimum value in the axial region of a third and/or a fourth sprocket as counted from outboard most sprocket.

9. The bicycle sprocket cassette of claim 1 wherein at least one sprocket of the plurality of coaxial sprockets has at least one stabilizing tooth.

10. The bicycle sprocket cassette of claim 9 , wherein an inboard-side tooth contact surface of the stabilizing tooth together with an outboard-side tooth contact surface of an chain inner link plate sprocket tooth having the largest axial chain inner link plate-guiding dimension of the at least one sprocket forms a chain-guiding dimension spanning multiple sprocket teeth which is wider than an axial chain inner link plate-guiding dimension of the inner link plate sprocket tooth having the largest axial chain inner link plate-guiding dimension such that the at least one sprocket is configured to deflect the bicycle roller chain inboard on the at least one sprocket via the inboard-side tooth contact surface of the stabilizing tooth.

11. The bicycle sprocket cassette of claim 10 , wherein the chain-guiding dimension spanning multiple sprocket teeth ranges between 0.90 times and 1.05 times of the chain inner link plate clearance width of the bicycle roller chain.

12. The bicycle sprocket cassette of claim 11 , wherein the chain-guiding dimension spanning multiple sprocket teeth ranges between 1.004 times and 1.033 times of a chain inner link plate clearance width of the bicycle roller chain.

13. The bicycle sprocket cassette of claim 9 , wherein an outboard-side tooth contact surface of the stabilizing tooth together with an inboard-side tooth contact surface of an chain inner link plate sprocket tooth having the largest axial chain inner link plate-guiding dimension of the at least one sprocket forms a chain-guiding dimension spanning multiple sprocket teeth which is wider than an axial chain inner link plate-guiding dimension of the inner link plate sprocket tooth having the largest axial chain inner link plate-guiding dimension such that the at least one sprocket is configured to deflect the bicycle roller chain outboard on the at least one sprocket via the outboard-side tooth contact surface of the stabilizing tooth.

14. The bicycle sprocket cassette of claim 13 , wherein the chain-guiding dimension spanning multiple sprocket teeth ranges between 0.90 times and 1.05 times of a chain inner link plate clearance width of the bicycle roller chain.

15. The bicycle sprocket cassette of claim 14 , wherein the chain-guiding dimension spanning multiple sprocket teeth ranges between 1.004 times and 1.033 times of the chain inner link plate clearance width of the bicycle roller chain.

16. A bicycle sprocket cassette for a bicycle drive system with a rear derailleur and a bicycle roller chain having a chain inner link plate clearance width, the bicycle sprocket cassette comprising:
a plurality of coaxial sprockets each having a different number of teeth, the plurality of coaxial sprockets each having a sprocket main body with sprocket teeth arranged thereon, wherein at least one sprocket of the plurality of coaxial sprockets has, in its outboard-side end face along a section of its circumference in the region of the sprocket main body and of the sprocket teeth, at least one upshift region with an axial upshift recess formation and/or at least one downshift region with an axial downshift recess formation to allow smooth shifting operation,
wherein at least one sprocket of the bicycle sprocket cassette has at least one stabilizing tooth, wherein an inboard-side tooth contact surface of the stabilizing tooth together with an outboard-side tooth contact surface of an chain inner link plate sprocket tooth having the largest axial chain inner link plate-guiding dimension of the least one sprocket forms a chain-guiding dimension spanning multiple sprocket teeth which is wider than the axial chain inner link plate-guiding dimension of the inner link plate sprocket tooth having the largest axial chain inner link plate-guiding dimension such that the at least one sprocket is configured to deflect the bicycle rolle

Assignees

• Sram De Gmbh

Inventors

• Buechner Sven
• Buettner Alex
• Heyna Sebastian
• Kommer Pierre
• Puls Arndt
• Rohmer Jakob
• Vonend Andreas

Classifications

• B62M9/04

  of changeable ratio · CPC title

• B62M9/10 Primary

  involving different-sized wheels, {e.g. rear sprocket chain wheels} selectively engaged by the chain, belt, or the like {(bicycle hubs rotatably arranged on axle B60B27/023)} · CPC title

• B62M9/12 Primary

  the chain, belt, or the like being laterally shiftable {, e.g. using a rear derailleur} · CPC title