Patents by Inventor Yasufumi FUKUNAGA

Yasufumi FUKUNAGA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11718369
    Abstract: A bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, and a torque transmitting profile. The sprocket body has an outer periphery and an inner periphery positioned radially inwardly from the outer periphery with respect to a rotational center axis of the bicycle sprocket. The plurality of sprocket teeth is disposed on the outer periphery of the sprocket body. The torque transmitting profile is positioned around the inner periphery of the sprocket body. The torque transmitting profile includes at least ten internal spline teeth. The at least ten internal spline-teeth include at least one first internal spline-tooth, at least one second internal spline-tooth and at least one third internal spline-tooth. The at least one internal first spline-tooth, the at least one second internal spline-tooth and the at least one third internal spline-tooth are different in shape from each other.
    Type: Grant
    Filed: October 12, 2022
    Date of Patent: August 8, 2023
    Assignee: SHIMANO INC.
    Inventors: Yasufumi Fukunaga, Shota Suyama
  • Publication number: 20230030458
    Abstract: A bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, and a torque transmitting profile. The sprocket body has an outer periphery and an inner periphery positioned radially inwardly from the outer periphery with respect to a rotational center axis of the bicycle sprocket. The plurality of sprocket teeth is disposed on the outer periphery of the sprocket body. The torque transmitting profile is positioned around the inner periphery of the sprocket body. The torque transmitting profile includes at least ten internal spline teeth. The at least ten internal spline-teeth include at least one first internal spline-tooth, at least one second internal spline-tooth and at least one third internal spline-tooth. The at least one internal first spline-tooth, the at least one second internal spline-tooth and the at least one third internal spline-tooth are different in shape from each other.
    Type: Application
    Filed: October 12, 2022
    Publication date: February 2, 2023
    Applicant: SHIMANO INC.
    Inventors: Yasufumi FUKUNAGA, Shota SUYAMA
  • Patent number: 11518474
    Abstract: A bicycle sprocket arrangement comprises a smaller sprocket and a larger sprocket. The larger sprocket has at least one upshifting facilitation area configured to facilitate an upshifting operation in which a bicycle chain is shifted from the larger sprocket toward the smaller sprocket. The at least one upshifting facilitation area includes an upstream tooth, an intermediate tooth, and a downstream tooth. The upstream tooth has a first recessed portion. The intermediate tooth has a second recessed portion. The downstream tooth has at least one of a third recessed portion and a chamfered portion. The at least one of the third recessed portion and the chamfered portion are separated from the second recessed portion.
    Type: Grant
    Filed: January 24, 2019
    Date of Patent: December 6, 2022
    Assignee: SHIMANO INC.
    Inventors: Yasufumi Fukunaga, Shota Suyama
  • Patent number: 11338887
    Abstract: A bicycle rear sprocket comprises a sprocket body and a plurality of sprocket teeth including a plurality of driving-noise reduction teeth. Each of the plurality of driving-noise reduction teeth comprises an upstream circumferential surface, a downstream circumferential surface, a first chamfer, and a second chamfer. The first chamfer has a first borderline relative to the bicycle outward surface. The second chamfer has a second borderline relative to the bicycle outward surface. A first opposite end of the first borderline and a second opposite end of the second borderline are disposed radially outwardly from each of a first end of the first borderline and a second end of the second borderline with respect to the rotational center axis. A total number of the plurality of driving-noise reduction teeth is equal to or larger than one-third of a total tooth-space number of the plurality of sprocket teeth.
    Type: Grant
    Filed: February 21, 2019
    Date of Patent: May 24, 2022
    Assignee: SHIMANO INC.
    Inventors: Yasufumi Fukunaga, Atsuhiro Emura, Kohei Hokai
  • Patent number: 11338886
    Abstract: A bicycle multiple sprocket comprises a plurality of sprockets. The plurality of sprockets includes a first sprocket and a second sprocket. The second sprocket includes a second sprocket body and a plurality of second sprocket teeth extending radially outwardly from the second sprocket body with respect to the rotational center axis. The plurality of second sprocket teeth includes at least one chain-curvature limiting tooth having a chain-curvature limiting surface configured to support an inner link plate of a bicycle chain in the axial direction in a chain-inclining state where the bicycle chain is inclined from the at least one chain-curvature limiting tooth toward the first sprocket so as to prevent one of a plurality of first sprocket teeth from engaging in an outer link space provided between an opposed pair of outer link plates of the bicycle chain.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: May 24, 2022
    Assignee: SHIMANO INC.
    Inventors: Yasufumi Fukunaga, Atsuhiro Emura
  • Patent number: 11028916
    Abstract: A bicycle sprocket includes a base body, a first sprocket tooth and a shifting initiation tooth. The first sprocket tooth includes a drive surface including a drive surface side tooth tip end portion, a non-drive surface including a non-drive surface side tooth tip end portion and a tooth tip portion connecting the drive surface side tooth tip end portion and the non-drive surface side tooth tip end portion. The non-drive surface extends circumferentially with respect to the rotational center axis from the non-drive surface side tooth tip end portion toward a first surface. The tooth tip portion extends circumferentially in a first direction between the drive surface side tooth tip end portion and the non-drive surface side tooth tip end portion. The non-drive surface extends circumferentially from the non-drive surface side tooth tip end portion in a second direction that is inclined with respect to the first direction.
    Type: Grant
    Filed: September 14, 2018
    Date of Patent: June 8, 2021
    Assignee: Shimano Inc.
    Inventors: Yasufumi Fukunaga, Tsuyoshi Fukumori
  • Patent number: 10933947
    Abstract: A bicycle sprocket comprises a sprocket body and a plurality of sprocket teeth including at least one first tooth to initially disengage with the bicycle chain in a shifting operation where the bicycle chain shifts from the bicycle sprocket to an adjacent smaller bicycle sprocket. At least one second tooth is disposed adjacent to the at least one first tooth at an upstream side of the at least one first tooth in a driving rotational direction of the bicycle sprocket. The at least one second tooth has a first tooth height. At least one third tooth is disposed adjacent to the at least one second tooth at the upstream side of the at least one second tooth. The at least one third tooth has a second tooth height longer than the first tooth height.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: March 2, 2021
    Assignee: SHIMANO INC.
    Inventor: Yasufumi Fukunaga
  • Patent number: 10926836
    Abstract: A bicycle rear sprocket assembly comprises a sprocket support and a first sprocket. The sprocket support includes a hub engagement part configured to engage with a bicycle hub assembly. The sprocket support includes a plurality of sprocket attachment members extending radially outwardly from the hub engagement part with respect to a rotational center axis of the bicycle rear sprocket assembly. The first sprocket is attached to the plurality of sprocket attachment members. The first sprocket includes a first sprocket body and a plurality of first sprocket teeth which extends radially outwardly from the first sprocket body with respect to the rotational center axis and a total number of which is equal to or larger than thirty-four. The first sprocket has a plurality of shifting facilitation areas. A total number of the plurality of shifting facilitation areas is a divisor of a total number of the plurality of sprocket attachment members.
    Type: Grant
    Filed: August 24, 2017
    Date of Patent: February 23, 2021
    Assignee: SHIMANO INC.
    Inventors: Hiroshi Fujita, Atsuhiro Emura, Yasufumi Fukunaga, Tsuyoshi Fukumori
  • Patent number: 10800487
    Abstract: A bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, and at least one upshifting facilitation area. The plurality of sprocket teeth extends radially outwardly from the sprocket body with respect to the rotational center axis. The plurality of sprocket teeth includes at least one axially recessed upshifting initiation tooth. The at least one axially recessed upshifting initiation tooth includes a driving surface, a non-driving surface and a tooth tip portion. The non-driving surface includes a non-driving surface protrusion disposed radially inwardly from a non-driving surface side tooth tip end with respect to a rotational center axis. The non-driving surface protrusion has a protrusion tip disposed closer to the second axially-facing surface than the non-driving-surface-side tooth tip end in the axial direction so that a guiding slope extends from the protrusion tip toward the first axially-facing surface.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: October 13, 2020
    Assignee: SHIMANO INC.
    Inventors: Atsuhiro Emura, Yasufumi Fukunaga, Tsuyoshi Fukumori
  • Publication number: 20200269953
    Abstract: A bicycle rear sprocket comprises a sprocket body and a plurality of sprocket teeth including a plurality of driving-noise reduction teeth. Each of the plurality of driving-noise reduction teeth comprises an upstream circumferential surface, a downstream circumferential surface, a first chamfer, and a second chamfer. The first chamfer has a first borderline relative to the bicycle outward surface. The second chamfer has a second borderline relative to the bicycle outward surface. A first opposite end of the first borderline and a second opposite end of the second borderline are disposed radially outwardly from each of a first end of the first borderline and a second end of the second borderline with respect to the rotational center axis. A total number of the plurality of driving-noise reduction teeth is equal to or larger than one-third of a total tooth-space number of the plurality of sprocket teeth.
    Type: Application
    Filed: February 21, 2019
    Publication date: August 27, 2020
    Applicant: SHIMANO INC.
    Inventors: Yasufumi FUKUNAGA, Atsuhiro EMURA, Kohei HOKAI
  • Publication number: 20200239106
    Abstract: A bicycle sprocket arrangement comprises a smaller sprocket and a larger sprocket. The larger sprocket has at least one upshifting facilitation area configured to facilitate an upshifting operation in which a bicycle chain is shifted from the larger sprocket toward the smaller sprocket. The at least one upshifting facilitation area includes an upstream tooth, an intermediate tooth, and a downstream tooth. The upstream tooth has a first recessed portion. The intermediate tooth has a second recessed portion. The downstream tooth has at least one of a third recessed portion and a chamfered portion. The at least one of the third recessed portion and the chamfered portion are separated from the second recessed portion.
    Type: Application
    Filed: January 24, 2019
    Publication date: July 30, 2020
    Applicant: SHIMANO INC.
    Inventors: Yasufumi FUKUNAGA, Shota SUYAMA
  • Patent number: 10717495
    Abstract: A bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, an axially outward protuberance, and an axially inward protuberance. The axially outward protuberance is disposed on an outward facing side of the sprocket body to overlap at least partly with a bicycle chain engaging with a neighboring bicycle sprocket when viewed along a rotational center axis. The axially inward protuberance is disposed on an inward facing side of the sprocket body to overlap at least partly with the axially outward protuberance when viewed along the rotational center axis.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: July 21, 2020
    Assignee: SHIMANO INC.
    Inventors: Yasufumi Fukunaga, Hiroshi Fujita, Tsuyoshi Fukumori, Atsuhiro Emura
  • Patent number: 10577051
    Abstract: A bicycle sprocket comprises a plurality of sprocket teeth including at least one first tooth and at least one second tooth. The at least one first tooth has a first non-driving surface including a first non-driving surface portion and a second non-driving surface portion so that a first ridge is formed between the first non-driving surface portion and the second non-driving surface portion. The at least one second tooth is configured to initially engage with the bicycle chain in a shifting operation. The at least one second tooth is disposed adjacent to the at least one first tooth. The at least one second tooth has a second non-driving surface including a third non-driving surface portion and a fourth non-driving surface portion so that a second ridge is formed between the third non-driving surface portion and the fourth non-driving surface portion.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: March 3, 2020
    Assignee: SHIMANO INC.
    Inventors: Yasufumi Fukunaga, Atsuhiro Emura
  • Publication number: 20190359284
    Abstract: A bicycle multiple sprocket comprises a plurality of sprockets. The plurality of sprockets includes a first sprocket and a second sprocket. The second sprocket includes a second sprocket body and a plurality of second sprocket teeth extending radially outwardly from the second sprocket body with respect to the rotational center axis. The plurality of second sprocket teeth includes at least one chain-curvature limiting tooth having a chain-curvature limiting surface configured to support an inner link plate of a bicycle chain in the axial direction in a chain-inclining state where the bicycle chain is inclined from the at least one chain-curvature limiting tooth toward the first sprocket so as to prevent one of a plurality of first sprocket teeth from engaging in an outer link space provided between an opposed pair of outer link plates of the bicycle chain.
    Type: Application
    Filed: May 24, 2018
    Publication date: November 28, 2019
    Applicant: SHIMANO INC.
    Inventors: Yasufumi FUKUNAGA, Atsuhiro EMURA
  • Publication number: 20190359285
    Abstract: A bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, and at least one upshifting facilitation area. The plurality of sprocket teeth extends radially outwardly from the sprocket body with respect to the rotational center axis. The plurality of sprocket teeth includes at least one axially recessed upshifting initiation tooth. The at least one axially recessed upshifting initiation tooth includes a driving surface, a non-driving surface and a tooth tip portion. The non-driving surface includes a non-driving surface protrusion disposed radially inwardly from a non-driving surface side tooth tip end with respect to a rotational center axis. The non-driving surface protrusion has a protrusion tip disposed closer to the second axially-facing surface than the non-driving-surface-side tooth tip end in the axial direction so that a guiding slope extends from the protrusion tip toward the first axially-facing surface.
    Type: Application
    Filed: May 24, 2018
    Publication date: November 28, 2019
    Applicant: SHIMANO INC.
    Inventors: Atsuhiro EMURA, Yasufumi FUKUNAGA, Tsuyoshi FUKUMORI
  • Publication number: 20190101204
    Abstract: A bicycle sprocket includes a base body, a first sprocket tooth and a shifting initiation tooth. The first sprocket tooth includes a drive surface including a drive surface side tooth tip end portion, a non-drive surface including a non-drive surface side tooth tip end portion and a tooth tip portion connecting the drive surface side tooth tip end portion and the non-drive surface side tooth tip end portion. The non-drive surface extends circumferentially with respect to the rotational center axis from the non-drive surface side tooth tip end portion toward a first surface. The tooth tip portion extends circumferentially in a first direction between the drive surface side tooth tip end portion and the non-drive surface side tooth tip end portion. The non-drive surface extends circumferentially from the non-drive surface side tooth tip end portion in a second direction that is inclined with respect to the first direction.
    Type: Application
    Filed: September 14, 2018
    Publication date: April 4, 2019
    Inventors: Yasufumi FUKUNAGA, Tsuyoshi FUKUMORI
  • Publication number: 20190084647
    Abstract: A bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, an axially outward protuberance, and an axially inward protuberance. The axially outward protuberance is disposed on an outward facing side of the sprocket body to overlap at least partly with a bicycle chain engaging with a neighboring bicycle sprocket when viewed along a rotational center axis. The axially inward protuberance is disposed on an inward facing side of the sprocket body to overlap at least partly with the axially outward protuberance when viewed along the rotational center axis.
    Type: Application
    Filed: September 15, 2017
    Publication date: March 21, 2019
    Applicant: SHIMANO INC.
    Inventors: Yasufumi FUKUNAGA, Hiroshi FUJITA, Tsuyoshi FUKUMORI, Atsuhiro EMURA
  • Publication number: 20190084648
    Abstract: A bicycle sprocket comprises a sprocket body and a plurality of sprocket teeth including at least one first tooth to initially disengage with the bicycle chain in a shifting operation where the bicycle chain shifts from the bicycle sprocket to an adjacent smaller bicycle sprocket. At least one second tooth is disposed adjacent to the at least one first tooth at an upstream side of the at least one first tooth in a driving rotational direction of the bicycle sprocket. The at least one second tooth has a first tooth height. At least one third tooth is disposed adjacent to the at least one second tooth at the upstream side of the at least one second tooth. The at least one third tooth has a second tooth height longer than the first tooth height.
    Type: Application
    Filed: September 15, 2017
    Publication date: March 21, 2019
    Applicant: SHIMANO INC.
    Inventor: Yasufumi FUKUNAGA
  • Publication number: 20190084649
    Abstract: A bicycle sprocket comprises a plurality of sprocket teeth including at least one first tooth and at least one second tooth. The at least one first tooth has a first non-driving surface including a first non-driving surface portion and a second non-driving surface portion so that a first ridge is formed between the first non-driving surface portion and the second non-driving surface portion. The at least one second tooth is configured to initially engage with the bicycle chain in a shifting operation. The at least one second tooth is disposed adjacent to the at least one first tooth. The at least one second tooth has a second non-driving surface including a third non-driving surface portion and a fourth non-driving surface portion so that a second ridge is formed between the third non-driving surface portion and the fourth non-driving surface portion.
    Type: Application
    Filed: September 15, 2017
    Publication date: March 21, 2019
    Applicant: SHIMANO INC.
    Inventors: Yasufumi FUKUNAGA, Atsuhiro EMURA
  • Publication number: 20190061873
    Abstract: A bicycle rear sprocket assembly comprises a sprocket support and a first sprocket. The sprocket support includes a hub engagement part configured to engage with a bicycle hub assembly. The sprocket support includes a plurality of sprocket attachment members extending radially outwardly from the hub engagement part with respect to a rotational center axis of the bicycle rear sprocket assembly. The first sprocket is attached to the plurality of sprocket attachment members. The first sprocket includes a first sprocket body and a plurality of first sprocket teeth which extends radially outwardly from the first sprocket body with respect to the rotational center axis and a total number of which is equal to or larger than thirty-four. The first sprocket has a plurality of shifting facilitation areas. A total number of the plurality of shifting facilitation areas is a divisor of a total number of the plurality of sprocket attachment members.
    Type: Application
    Filed: August 24, 2017
    Publication date: February 28, 2019
    Applicant: SHIMANO INC.
    Inventors: Hiroshi FUJITA, Atsuhiro EMURA, Yasufumi FUKUNAGA, Tsuyoshi FUKUMORI