# US 10,309,515 B2 · Bicycle rear sprocket > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,515 B2 - Document ID: US10309515B2 - Status: Granted - Kind: B2 - Application number: 15/489,675 - Filed: 2017-04-17 - Published: 2018-10-18 - Granted: 2019-06-04 - Earliest claimed: 2017-04-17 - Assignees: Shimano Inc. - Applicants: Shimano Inc. - Inventors: Akihiro Ohno; Toshinari Oishi; Tsuyoshi Fukumori - Web page: https://patentgrep.com/patent/US10309515B2 ## CPC - F16H 55/30: Chain-wheels - B62M 9/10: 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)} - F16H: GEARING - B62M: RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR {SINGLE-TRACK} CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES (arrangements or mounting of transmissions in vehicles in general B60K; transmission elements per se F16) ## Abstract A bicycle rear sprocket comprises a sprocket body, a plurality of sprocket teeth, a shifting facilitation recess, and an upshifting facilitation projection. The plurality of sprocket teeth extends radially outwardly from the sprocket body. The shifting facilitation recess is to facilitate a shifting operation in which a bicycle chain is shifted between the bicycle rear sprocket and a smaller rear sprocket adjacent to the bicycle rear sprocket without another sprocket between the bicycle rear sprocket and the smaller rear sprocket. The upshifting facilitation projection is provided in the shifting facilitation recess to support the bicycle chain in an upshifting operation in which the bicycle chain is shifted from the bicycle rear sprocket to the smaller rear sprocket. ## Claims ### Claim 1 A bicycle rear sprocket comprising: a sprocket body; a plurality of sprocket teeth extending radially outwardly from the sprocket body; a shifting facilitation recess to facilitate a shifting operation in which a bicycle chain is shifted between the bicycle rear sprocket and a smaller rear sprocket adjacent to the bicycle rear sprocket without another sprocket between the bicycle rear sprocket and the smaller rear sprocket; and an upshifting facilitation projection provided in the shifting facilitation recess to support the bicycle chain in an upshifting operation in which the bicycle chain is shifted from the bicycle rear sprocket to the smaller rear sprocket. ### Claim 2 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the upshifting facilitation projection is integrally provided with the sprocket body as a one-piece unitary member. ### Claim 3 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the upshifting facilitation projection is a separate member from the sprocket body. ### Claim 4 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the upshifting facilitation projection includes a chain contact surface contactable with the bicycle chain in the upshifting operation, the chain contact surface is inclined relative to a sprocket center plane perpendicular to a rotational center axis of the bicycle rear sprocket, and the sprocket center plane bisects the bicycle rear sprocket in an axial direction with respect to the rotational center axis. ### Claim 5 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the upshifting facilitation projection includes a chain contact surface contactable with the bicycle chain in the upshifting operation, and the chain contact surface extends in an axial direction with respect to a rotational center axis of the bicycle rear sprocket. ### Claim 6 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the upshifting facilitation projection includes a chain contact surface contactable with the bicycle chain in the upshifting operation, and the chain contact surface includes a flat surface. ### Claim 7 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the upshifting facilitation projection includes a chain contact surface contactable with the bicycle chain in the upshifting operation, and the chain contact surface is inclined relative to a first radial direction perpendicular to a rotational center axis of the bicycle rear sprocket, the first radial direction extending from the rotational center axis to the upshifting facilitation projection. ### Claim 8 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the upshifting facilitation projection includes a chain contact surface contactable with the bicycle chain in the upshifting operation, the chain contact surface includes a first circumferential end and a second circumferential end, the chain contact surface extends between the first circumferential end and the second circumferential end, and a first radial distance provided between a rotational center axis of the bicycle rear sprocket and the first circumferential end is different from a second radial distance provided between the rotational center axis and the second circumferential end. ### Claim 9 (depends on 8) The bicycle rear sprocket according to claim 8, wherein the first circumferential end is provided on an upstream side of the second circumferential end in a driving rotational direction in which the bicycle rear sprocket is rotated about the rotational center axis during pedaling, and the first radial distance is smaller than the second radial distance. ### Claim 10 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the plurality of sprocket teeth includes a first tooth and a second tooth, the first tooth and the second tooth are provided in an angular range of the shifting facilitation recess, and the upshifting facilitation projection is provided between the first tooth and the second tooth in a circumferential direction with respect to a rotational center axis of the bicycle rear sprocket. ### Claim 11 (depends on 10) The bicycle rear sprocket according to claim 10, wherein the shifting facilitation recess is continuously provided between the first tooth and the second tooth through the upshifting facilitation projection. ### Claim 12 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the plurality of sprocket teeth includes at least one driving tooth. ### Claim 13 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the plurality of sprocket teeth includes a first driving tooth and a second driving tooth, the first driving tooth has a first maximum axial width extending in an axial direction with respect to a rotational center axis of the bicycle rear sprocket, the second driving tooth has a second maximum axial width extending in the axial direction, and the first maximum axial width is larger than the second maximum axial width. ### Claim 14 (depends on 1) The bicycle rear sprocket according to claim 1, wherein the sprocket body includes a first axial surface and a second axial surface provided on a reverse side of the first axial surface in an axial direction with respect to a rotational center axis of the bicycle rear sprocket, and an axial end of the upshifting facilitation projection is provided in an axial area extending from the first axial surface to the second axial surface.