Patents by Inventor Yasuhiro Yahata

Yasuhiro Yahata 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: 6666786
    Abstract: A chamfered sprocket assembly for facilitating the shifting of a drive chain from a larger sprocket to a smaller sprocket is disclosed. In a preferred embodiment, the chamfered sprocket assembly includes a sprocket having a plurality of chamfered portions on a side facing a smaller sprocket, each chamfered portion located between a pair of toothlike projections located on the rim of the sprocket body. The chamfered portions preferably include a crest which tapers toward a first edge and a second edge of the chamfer portion, respectively. The crest is preferably offset from the center of the chamfer portion toward the driving direction of the sprocket assembly. To further facilitate the shifting of the drive chain, the sprocket preferably includes a rounded shoulder to guide the movement of the drive chain. Finally, the friction between the toothlike projections and the drive chain is reduced by polishing the toothlike projections.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: December 23, 2003
    Assignee: Shimano Inc.
    Inventor: Yasuhiro Yahata
  • Publication number: 20020086753
    Abstract: A chamfered sprocket assembly for facilitating the shifting of a drive chain from a larger sprocket to a smaller sprocket is disclosed. In a preferred embodiment, the chamfered sprocket assembly includes a sprocket having a plurality of chamfered portions on a side facing a smaller sprocket, each chamfered portion located between a pair of toothlike projections located on the rim of the sprocket body. The chamfered portions preferably include a crest which tapers toward a first edge and a second edge of the chamfer portion, respectively. The crest is preferably offset from the center of the chamfer portion toward the driving direction of the sprocket assembly. To further facilitate the shifting of the drive chain, the sprocket preferably includes a rounded shoulder to guide the movement of the drive chain. Finally, the friction between the toothlike projections and the drive chain is reduced by polishing the toothlike projections.
    Type: Application
    Filed: June 11, 2001
    Publication date: July 4, 2002
    Applicant: Shimano Inc.
    Inventor: Yasuhiro Yahata
  • Patent number: 6202813
    Abstract: A ratchet mechanism for a bicycle hub includes a first hub member and a second hub member, wherein the first hub member and the second hub member are rotatable relative to each other. A pawl is supported by the first hub member, a ratchet tooth is supported by the second hub member, and a biasing mechanism is provided for biasing the pawl toward the ratchet tooth. A pawl control mechanism is responsive to relative rotation of the first hub member and the second hub member for allowing the pawl to contact the ratchet tooth when the first hub member and the second hub member rotate relative to each other in one direction and for preventing the pawl from contacting the ratchet tooth when the first hub member and the second hub member rotate relative to each other in an opposite direction.
    Type: Grant
    Filed: January 27, 1997
    Date of Patent: March 20, 2001
    Assignee: Shimano, Inc.
    Inventors: Yasuhiro Yahata, Koshi Tabe
  • Patent number: 5882088
    Abstract: A bicycle hub apparatus is constructed of a hub shell and a plurality of spoke attachment parts disposed circumferentially about the hub shell at opposite end portions of the hub shell, wherein each spoke attachment part includes a first through hole and a second through hole. In each spoke attachment part, the first through hole is located at a different radial position relative to a central hub axis of the hub shell when compared to the second through hole.
    Type: Grant
    Filed: January 16, 1997
    Date of Patent: March 16, 1999
    Assignee: Shimano, Inc.
    Inventor: Yasuhiro Yahata
  • Patent number: D421951
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: March 28, 2000
    Assignee: Shimano Inc.
    Inventor: Yasuhiro Yahata