Bicycle transmission apparatus

Patent metadata

Field	Value
Publication number	US-9789928-B2
Application number	US-201615013955-A
Country	US
Kind code	B2
Filing date	Feb 2, 2016
Priority date	Mar 6, 2015
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A bicycle transmission apparatus comprises a base member, a first transmission member, a second transmission member, and a first coupling member. The first transmission member is rotatable relative to the base member about a first rotational axis and is movable relative to the base member in an axial direction parallel to the first rotational axis. The second transmission member is rotatable relative to the base member about a second rotational axis and is stationary relative to the base member in the axial direction. The first coupling member is configured to couple the first transmission member to the second transmission member to transmit rotation of the first transmission member to the second transmission member at a variable speed stage which is variable in accordance with at least one positional relationship among the first transmission member, the second transmission member, and the first coupling member in the axial direction.

First claim

What is claimed is:

1. A bicycle transmission apparatus comprising:
a base member;
a first transmission member rotatable relative to the base member about a first rotational axis and movable relative to the base member in an axial direction parallel to the first rotational axis;
a second transmission member rotatable relative to the base member about a second rotational axis and stationary relative to the base member in the axial direction; and
a first coupling member configured to couple the first transmission member to the second transmission member to transmit rotation of the first transmission member to the second transmission member at a variable speed stage, the variable speed stage being variable in accordance with at least one positional relationship among the first transmission member, the second transmission member, and the first coupling member in the axial direction, wherein
the first transmission member includes first cogwheels, and the second transmission member includes second cogwheels, and
the first coupling member couples one of the first cogwheels to one of the second cogwheels.

2. A bicycle transmission apparatus comprising:
a base member;
a first transmission member rotatable relative to the base member about a first rotational axis and movable relative to the base member in an axial direction parallel to the first rotational axis;
a second transmission member rotatable relative to the base member about a second rotational axis and stationary relative to the base member in the axial direction; and
a first coupling member configured to couple the first transmission member to the second transmission member to transmit rotation of the first transmission member to the second transmission member at a variable speed stage, the variable speed stage being variable in accordance with at least one positional relationship among the first transmission member, the second transmission member, and the first coupling member in the axial direction, wherein
the axial direction includes a first axial direction and a second axial direction opposite to the first axial direction,
the first transmission member is movable relative to the base member and the first coupling member in the first axial direction without changing an axial relative position between the first coupling member and the second transmission member during one of upshifting and downshifting, and
the first transmission member is movable together with the first coupling member relative to the base member in the second axial direction so as to change the axial relative position between the first coupling member and the second transmission member during the one of upshifting and downshifting.

3. The bicycle transmission apparatus according to claim 2 , further comprising:
a positioning device configured to position the first transmission member relative to the base member in the axial direction at each of axial positions.

4. The bicycle transmission apparatus according to claim 3 , wherein
the positioning device is configured to position the first transmission member relative to the base member in the axial direction at each of a first axial position and a second axial position,
the first transmission member is movable relative to the base member in the first axial direction from the first axial position to the second axial position, and
the first transmission member is movable relative to the base member in the second axial direction from the second axial position to the first axial position.

5. The bicycle transmission apparatus according to claim 4 , further comprising:
a switching device configured to switch a position of the first transmission member relative to the base member in the axial direction between the first axial position and the second axial position.

6. The bicycle transmission apparatus according to claim 3 , further comprising:
a first shaft defining the first rotational axis; and
a bearing structure configured to rotatably couple the first transmission member to the first shaft about the first rotational axis, wherein
the first transmission member has a first opening,
the first shaft extends through the first opening, and
the bearing structure is provided in the first opening.

7. The bicycle transmission apparatus according to claim 2 , wherein
the variable speed stage includes speed stages different from each other,
the first transmission member includes first cogwheels arranged in the axial direction, and
each of the first cogwheels is engageable with the first coupling member.

8. The bicycle transmission apparatus according to claim 7 , wherein
the second transmission member includes second cogwheels arranged in the axial direction,
each of the second cogwheels is engageable with the first coupling member, and
the second cogwheels respectively define the speed stages together with the first cogwheels.

9. The bicycle transmission apparatus according to claim 8 , wherein
a total number of the first cogwheels is equal to a total number of the second cogwheels.

10. The bicycle transmission apparatus according to claim 9 , wherein
each of the first cogwheels includes first teeth arranged in a circumferential direction of the first transmission member,
each of the second cogwheels includes second teeth arranged in a circumferential direction of the second transmission member,
the first cogwheels respectively have first pitch circles each defined by the first teeth,
the second cogwheels respectively have second pitch circles each defined by the second teeth, and
first diameters of the first pitch circles respectively are equal to second diameters of the second pitch circles.

11. The bicycle transmission apparatus according to claim 7 , wherein
the first cogwheels include a first largest cogwheel and a first smallest cogwheel,
the first smallest cogwheel has an outer diameter smaller than an outer diameter of the first largest cogwheel, and
the first smallest cogwheel is spaced apart from the first largest cogwheel in the first axial direction.

12. The bicycle transmission apparatus according to claim 1 , further comprising:
a guide device configured to guide the first coupling member to change at least one of
a first relative position between the first coupling member and the first transmission member, and
a second relative position between the first coupling member and the second transmission member.

13. The bicycle transmission apparatus according to claim 12 , wherein
the guide device includes
a guide member contactable with the first coupling member, and
a guide unit configured to guide the guide member in a first guide direction to change at least one of the first relative position and the second relative position.

14. The bicycle transmission apparatus according to claim 13 , wherein
the guide device includes a tensioner contactable with the first coupling member,
the guide unit is configured to guide the tensioner in a second guide direction to adjust tension of the first coupling member, and
the second guide direction is different from the first guide direction and the axial direction.

15. The bicycle transmission apparatus according to claim 14 , wherein
the guide device includes a guide actuator configured to move the guide member in the first guide direction.

16. The bicycle transmission apparatus according to claim 15 , further comprising:
a sensing device configured to sense a pedaling state of a bicycle; and
a transmission controller configured to control the guide actuator to change a timing at which the guide member mo

Assignees

• Shimano Kk

Inventors

• Emura Atsuhiro
• Oishi Toshinari
• Nishimoto Yusuke
• Yamaguchi Sota
• Obuchi Kohei

Classifications

• B62M9/132

  electrically or fluid actuated; Controls thereof · CPC title

• F16H57/05

  of chains · CPC title

• B62M25/08

  with electrical or fluid transmitting systems · CPC title

• B62M9/134 Primary

  Mechanisms for shifting laterally · CPC title

• B62M6/50 Primary

  characterised by detectors or sensors, or arrangement thereof · CPC title