Bicycle crank assembly

Patent metadata

Field	Value
Publication number	US-10625814-B2
Application number	US-201615160479-A
Country	US
Kind code	B2
Filing date	May 20, 2016
Priority date	Jun 16, 2015
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A bicycle crank assembly has a sprocket, a first crank arm, a second crank arm and a crank axle, A first axial distance is defined between the first pedal attachment surface and the second pedal attachment surface in an axial direction. A second axial distance is defined between the first transverse center plane of the sprocket and the second axial center plane of the crank axle in the axial direction. The first axial distance is smaller than or equal to 170 mm. The second axial distance is larger than or equal to 55 mm.

First claim

What is claimed is:

1. A driving portion for a bicycle comprising: a bicycle crank assembly comprising:
a sprocket including a first transverse center plane that is transverse to the rotational center axis;
a crank axle including a second transverse center plane that is transverse to the rotational center axis;
a first crank arm including a first pedal attachment surface; and
a second crank arm including a second pedal attachment surface; and
a rear sprocket assembly having
a largest sprocket with a tooth count of forty, forty-two, forty-six, or forty-eight, and
a smallest sprocket having a tooth count of eleven or twelve,
the tooth count of the largest sprocket being forty-six in the case of the tooth count of the smallest sprocket being twelve,

the first pedal attachment surface being spaced from the second pedal attachment surface in an axial direction parallel to the rotational center axis by a first axial distance that is smaller than or equal to 170 mm, and
the first transverse center plane of the sprocket being spaced from the second transverse center plane of the crank axle in the axial direction by a second axial distance that is larger than or equal to 55 mm.

2. The driving portion according to the claim 1 , wherein
first axial distance is smaller than or equal to 165 mm.

3. The driving portion according to the claim 1 , wherein
the second axial distance is larger than or equal to 57 mm.

4. The driving portion according to the claim 1 , wherein
the first axial distance is larger than or equal to 90 mm.

5. The driving portion according to the claim 1 , wherein
the second axial distance is smaller than or equal to 85 mm.

6. The driving portion according to the claim 1 , wherein
the total number of the sprocket consists of one.

7. The driving portion according to the claim 1 , wherein
the second axial distance is smaller than the first axial distance.

8. The driving portion according to the claim 1 , wherein
the first transverse center plane and the second transverse center plane are positioned between the first pedal attachment surface and the second pedal attachment surface in the axial direction.

9. The driving portion according to the claim 1 , wherein
the first pedal attachment surface and the second pedal attachment surface face outwardly from the second transverse center plane in the axial direction, respectively.

10. The driving portion according to the claim 1 , wherein
the crank axle includes a first axial end surface and a second axial end surface opposite to the first axial end surface with respect to the second transverse center plane; and
the second transverse center plane is positioned in a middle position in the axially direction between the first axial end surface and the second axial end surface.

Assignees

• Shimano Kk

Inventors

• Kamada Kenji

Classifications

• B62M9/00

  Transmissions characterised by use of an endless chain, belt, or the like (cycle chain guards B62J13/00) · CPC title

• B62M9/10

  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

• B62M1/36 Primary

  with rotary cranks, e.g. with pedal cranks (B62M1/34 takes precedence; combined with reciprocating levers B62M1/26; cranks which can be immobilised as foot rests B62M5/00) · CPC title

• B62M3/00 Primary

  Construction of cranks operated by hand or foot · CPC title

• B62M9/105 Primary

  involving front sprocket chain-wheels engaged by the chain, belt or the like · CPC title