Patents by Inventor Kokichi Hamamoto

Kokichi Hamamoto 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).

  • Publication number: 20240026977
    Abstract: A sealing device includes a seal lip slidably contacting an outer surface of an inside member and seals liquid in an internal space of an outside member. The seal lip has a liquid-side inclined surface, an atmosphere-side inclined surface, and a lip edge between the liquid-side and atmosphere-side inclined surfaces and extending circumferentially. Helical ribs contacting the outer surface of the inside member are on the atmosphere-side inclined surface, and incline relative to the lip edge. Each rib has a linear portion having parallel side walls and a ship-bottom-shaped portion curving to expand further than the side walls, the linear portion extends from the lip edge, and the ship-bottom-shaped portion is farther from the lip edge than the linear portion. A height of each linear portion relative to the atmosphere-side inclined surface is 5 ?m to 37 ?m.
    Type: Application
    Filed: July 29, 2021
    Publication date: January 25, 2024
    Inventors: Hiroka YAMAGUCHI, Kokichi HAMAMOTO, Hideaki NAGAHAMAYA, Yuki SATO, Kenya YOSHIOKA
  • Patent number: 11835136
    Abstract: A sealing device capable of suppressing depletion of lubricant is provided. A sliding surface of a side lip 220 at a position away from a distal end of the side lip 220 is provided with a plurality of annular grooves 222 adjacent each other, each of all parts that form annular protrusions 223 between adjacent annular grooves 222 protrudes most at a center in a width direction thereof, with an amount of protrusion gradually decreasing with increasing separation from the center, and both sides of the center in the width direction are symmetric in shape. A tip portion of the sliding surface of the side lip 220 on the distal side of a region, which is provided with the plurality of annular grooves 222, is configured to make a planar contact with an end face of the annular member.
    Type: Grant
    Filed: April 15, 2020
    Date of Patent: December 5, 2023
    Assignee: NOK CORPORATION
    Inventors: Toshiki Watanabe, Kokichi Hamamoto, Tomoaki Nishimura, Masayuki Tanida
  • Patent number: 11668397
    Abstract: A sealing structure for a front cover of an engine includes a front cover made of resin of an engine in which a through-hole, into which a boss part of a torsional damper is to be inserted, is provided, and a sealing apparatus to seal between the through-hole of the front cover and the shaft part. The sealing apparatus includes a support ring that is made of resin and has an annular shape, and an elastic body part that is made of an elastic material, has an annular shape and is attached to the support ring. The elastic body part has an annular seal lip that contacts the shaft part such that the shaft part is able to slide, and the support ring is bonded to the front cover.
    Type: Grant
    Filed: August 9, 2019
    Date of Patent: June 6, 2023
    Inventors: Shiho Shonai, Hiromi Sugihara, Kokichi Hamamoto, Tomoaki Nishimura
  • Patent number: 11460110
    Abstract: A sealing device includes a reinforcing ring and an elastic body part. The elastic body part includes an annular seal lip, an annular dust lip, and an annular side lip that extends toward an outer side on an outer periphery side of the dust lip. The side lip includes an annular middle portion that increases in diameter as progress toward the outer side and an annular distal end portion that is a portion connected to and on the outer side of the middle portion and that increases in diameter as progress toward the outer side. In the side lip, the distal end portion is bent to an inner periphery side from the middle portion. In the middle portion, at least one groove is formed annularly around an axis x.
    Type: Grant
    Filed: April 2, 2019
    Date of Patent: October 4, 2022
    Assignee: NOK CORPORATION
    Inventors: Toshiki Watanabe, Kokichi Hamamoto, Tomoaki Nishimura, Hiromi Sugihara
  • Publication number: 20220163117
    Abstract: A sealing device capable of suppressing depletion of lubricant is provided. A sliding surface of a side lip 220 at a position away from a distal end of the side lip 220 is provided with a plurality of annular grooves 222 adjacent each other, each of all parts that form annular protrusions 223 between adjacent annular grooves 222 protrudes most at a center in a width direction thereof, with an amount of protrusion gradually decreasing with increasing separation from the center, and both sides of the center in the width direction are symmetric in shape. A tip portion of the sliding surface of the side lip 220 on the distal side of a region, which is provided with the plurality of annular grooves 222, is configured to make a planar contact with an end face of the annular member.
    Type: Application
    Filed: April 15, 2020
    Publication date: May 26, 2022
    Applicant: NOK CORPORATION
    Inventors: Toshiki WATANABE, Kokichi HAMAMOTO, Tomoaki NISHIMURA, Masayuki TANIDA
  • Patent number: 11287042
    Abstract: A sealing apparatus which seals an annular gap of a hole into which a shaft is to be inserted, includes a sealing apparatus body to be fitted into the hole, and a slinger to be attached to the shaft. The sealing apparatus body includes a reinforcing ring annular around an axis line, and an elastic body portion attached to the reinforcing ring and annular around the axis line. The slinger includes a flange portion extending toward an outer periphery side and annular around the axis line. The elastic body portion includes an end-face lip extending on one side in an axis line direction, contacting the flange portion from another side in the axis line direction, and annular around the axis line.
    Type: Grant
    Filed: May 28, 2019
    Date of Patent: March 29, 2022
    Assignee: NOK CORPORATION
    Inventors: Yuya Sakano, Hiroki Matsui, Kokichi Hamamoto, Takehiro Nakagawa, Hisato Yonai, Masahiko Inoue
  • Patent number: 11261968
    Abstract: A sealing device includes an annular reinforcing ring and an elastic body part, and the elastic body part has an annular seal lip, an annular dust lip, and an annular side lip. The side lip extends toward the outer side on an outer periphery side of the dust lip, and includes a distal end portion, a middle portion, and a root portion. The root portion is an annular portion, the middle portion is a portion that is outside of the root portion, and an annular portion that increases in diameter toward an outward side, and the distal end portion is a portion that is outside the middle portion, and an annular portion that increases in diameter toward an outward side. The distal end portion is bent to an inner periphery side from the middle portion.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: March 1, 2022
    Assignee: NOK CORPORATION
    Inventors: Hideaki Nagahamaya, Kokichi Hamamoto, Masayuki Tanida, Takehiro Nakagawa
  • Publication number: 20210215251
    Abstract: A sealing structure for a front cover of an engine includes a front cover made of resin of an engine in which a through-hole, into which a boss part of a torsional damper is to be inserted, is provided, and a sealing apparatus to seal between the through-hole of the front cover and the shaft part. The sealing apparatus includes a support ring that is made of resin and has an annular shape, and an elastic body part that is made of an elastic material, has an annular shape and is attached to the support ring. The elastic body part has an annular seal lip that contacts the shaft part such that the shaft part is able to slide, and the support ring is bonded to the front cover.
    Type: Application
    Filed: August 9, 2019
    Publication date: July 15, 2021
    Inventors: Shiho SHONAI, Hiromi SUGIHARA, Kokichi HAMAMOTO, Tomoaki NISHIMURA
  • Publication number: 20210080007
    Abstract: A sealing device includes a reinforcing ring and an elastic body part. The elastic body part includes an annular seal lip, an annular dust lip, and an annular side lip that extends toward an outer side on an outer periphery side of the dust lip. The side lip includes an annular middle portion that increases in diameter as progress toward the outer side and an annular distal end portion that is a portion connected to and on the outer side of the middle portion and that increases in diameter as progress toward the outer side. In the side lip, the distal end portion is bent to an inner periphery side from the middle portion. In the middle portion, at least one groove is formed annularly around an axis x.
    Type: Application
    Filed: April 2, 2019
    Publication date: March 18, 2021
    Applicant: NOK CORPORATION
    Inventors: Toshiki WATANABE, Kokichi HAMAMOTO, Tomoaki NISHIMURA, Hiromi SUGIHARA
  • Publication number: 20200124178
    Abstract: A sealing apparatus includes a sealing apparatus body and a slinger. The sealing apparatus body includes a reinforcing ring annular around an axis line, and an elastic body portion attached to the reinforcing ring and annular around the axis line. The slinger includes a flange portion extending toward an outer peripheral side and annular around the axis line. The elastic body portion includes an annular end-face lip contacting the flange portion from another side in the axis line direction. At least one groove is formed on the other side of the flange portion of the slinger. At least one circumferential-direction projection is formed on an inner peripheral surface of the end-face lip. The circumferential-direction projection extends in an annular shape around the axis line and projects between the inner peripheral surface of the end-face lip and a surface of the flange portion on the other side.
    Type: Application
    Filed: December 17, 2019
    Publication date: April 23, 2020
    Inventors: Yuya SAKANO, Hiroki MATSUI, Kokichi HAMAMOTO, Takehiro NAKAGAWA, Hisato YONAI
  • Publication number: 20200011423
    Abstract: A sealing apparatus 1 includes a sealing apparatus body 2 and a slinger 3. The sealing apparatus body 2 includes an annular reinforcing ring 10 and an annular elastic body portion 20 formed of an elastic body mounted on the reinforcing ring 10. The slinger 3 includes a flange portion 31 which is an annular portion extending toward an outer peripheral side. The elastic body portion 20 includes an end-face lip 21 which is an annular lip extending toward an inner side and contacts the flange portion 31 from an outer side. At least one groove 33 is formed on an outer side of the flange portion 31 of the slinger 3, on a surface of the end-face lip 21 on an inner peripheral side, a plurality of radial projections 23 are formed side by side in a circumferential direction, and at least one circumferential projection 24 is formed.
    Type: Application
    Filed: September 20, 2019
    Publication date: January 9, 2020
    Inventors: Sosuke ITO, Masahiko INOUE, Yuya SAKANO, Hiroki MATSUI, Kokichi HAMAMOTO, Takehiro NAKAGAWA, Hisato YONAI
  • Publication number: 20190277403
    Abstract: A sealing apparatus which seals an annular gap of a hole into which a shaft is to be inserted, includes a sealing apparatus body to be fitted into the hole, and a slinger to be attached to the shaft. The sealing apparatus body includes a reinforcing ring annular around an axis line, and an elastic body portion attached to the reinforcing ring and annular around the axis line. The slinger includes a flange portion extending toward an outer periphery side and annular around the axis line. The elastic body portion includes an end-face lip extending on one side in an axis line direction, contacting the flange portion from another side in the axis line direction, and annular around the axis line.
    Type: Application
    Filed: May 28, 2019
    Publication date: September 12, 2019
    Inventors: Yuya SAKANO, Hiroki MATSUI, Kokichi HAMAMOTO, Takehiro NAKAGAWA, Hisato YONAI, Masahiko INOUE
  • Patent number: 10208861
    Abstract: A sealing device capable of preventing turnover of a dust lip and damage to a dust lip caused by insertion of a shaft. A bumper portion (125) made of a rubber-like elastic body and reducing an impact that the dust lip (122) receives from the shaft when the shaft is inserted into the sealing device (100) is provided on the side opposite to the sealed area (O) with respect to the dust lip (122), and an inner diameter of a tip of the bumper portion (125) on an inner peripheral side is set to be larger than an outer diameter of a part of the shaft on which a main lip (121) and the dust lip (122) slide and to be smaller than an inner diameter of a part having the largest inner diameter in a portion connecting the main lip (121) and the dust lip (122).
    Type: Grant
    Filed: May 15, 2015
    Date of Patent: February 19, 2019
    Assignee: NOK CORPORATION
    Inventors: Kokichi Hamamoto, Takehiro Nakagawa, Hideaki Nagahamaya, Shiho Sato
  • Publication number: 20180209546
    Abstract: A sealing device includes an annular reinforcing ring and an elastic body part, and the elastic body part has an annular seal lip, an annular dust lip, and an annular side lip. The side lip extends toward the outer side on an outer periphery side of the dust lip, and includes a distal end portion, a middle portion, and a root portion. The root portion is an annular portion, the middle portion is a portion that is outside of the root portion, and an annular portion that increases in diameter toward an outward side, and the distal end portion is a portion that is outside the middle portion, and an annular portion that increases in diameter toward an outward side. The distal end portion is bent to an inner periphery side from the middle portion.
    Type: Application
    Filed: March 22, 2018
    Publication date: July 26, 2018
    Inventors: Hideaki NAGAHAMAYA, Kokichi HAMAMOTO, Masayuki TANIDA, Takehiro NAKAGAWA
  • Publication number: 20170122438
    Abstract: A sealing device capable of preventing turnover of a dust lip and damage to a dust lip caused by insertion of a shaft. A bumper portion (125) made of a rubber-like elastic body and reducing an impact that the dust lip (122) receives from the shaft when the shaft is inserted into the sealing device (100) is provided on the side opposite to the sealed area (O) with respect to the dust lip (122), and an inner diameter of a tip of the bumper portion (125) on an inner peripheral side is set to be larger than an outer diameter of a part of the shaft on which a main lip (121) and the dust lip (122) slide and to be smaller than an inner diameter of a part having the largest inner diameter in a portion connecting the main lip (121) and the dust lip (122).
    Type: Application
    Filed: May 15, 2015
    Publication date: May 4, 2017
    Inventors: Kokichi HAMAMOTO, Takehiro NAKAGAWA, Hideaki NAGAHAMAYA, Shiho SATO
  • Patent number: 9303768
    Abstract: A valve stem seal device has a valve stem guide, a cylindrical metallic ring retained to an outer periphery of the valve stem guide, a rubbery elastic seal lip integrally formed in one end side of the metallic ring, and hermetically sliding to the valve stem, and a valve stem seal having the cylindrical metallic ring and the seal lip and fixed to the valve stem guide side. The valve stem seal device has a stop ring retained between a circular-truncated-cone-shaped surface which is expanded toward a side of the seal lip formed in an outer peripheral surface of the valve stem guide, and a cylindrical inner peripheral surface of the metallic ring. The stop ring has a cut part, and a movement limiting means for limiting a movement in an axial direction of the stop ring is provided in the other end side of the metallic ring.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: April 5, 2016
    Assignee: NOK Corporation
    Inventors: Yasunari Hamaya, Kokichi Hamamoto
  • Patent number: 9133938
    Abstract: A sealing device with a lip edge portion 2a and a sealing-space-opposite-side conical surface 2b whose diameter increases from the lip edge portion 2a toward a sealing space B opposite side is formed on an inner peripheral surface of a seal lip 2, and a first thread ridge 21 that obliquely extends in a given direction with respect to a circumferential direction, a second thread ridge 22 that obliquely extends in a direction opposite to the direction in which the first thread ridge 21 obliquely extends, and a circumferential ridge 23 that extends in the circumferential direction while intersecting the first thread ridge 21 and the second thread ridge 22 are formed on the sealing-space-opposite-side conical surface 2b.
    Type: Grant
    Filed: September 23, 2014
    Date of Patent: September 15, 2015
    Assignee: NOK CORPORATION
    Inventor: Kokichi Hamamoto
  • Publication number: 20150097344
    Abstract: A sealing device with a lip edge portion 2a and a sealing-space-opposite-side conical surface 2b whose diameter increases from the lip edge portion 2a toward a sealing space B opposite side is formed on an inner peripheral surface of a seal lip 2, and a first thread ridge 21 that obliquely extends in a given direction with respect to a circumferential direction, a second thread ridge 22 that obliquely extends in a direction opposite to the direction in which the first thread ridge 21 obliquely extends, and a circumferential ridge 23 that extends in the circumferential direction while intersecting the first thread ridge 21 and the second thread ridge 22 are formed on the sealing-space-opposite-side conical surface 2b.
    Type: Application
    Filed: September 23, 2014
    Publication date: April 9, 2015
    Inventor: Kokichi HAMAMOTO
  • Patent number: D802104
    Type: Grant
    Filed: March 23, 2016
    Date of Patent: November 7, 2017
    Assignee: NOK CORPORATION
    Inventors: Hideaki Nagahamaya, Kokichi Hamamoto, Masayuki Tanida, Takehiro Nakagawa
  • Patent number: D865134
    Type: Grant
    Filed: September 22, 2017
    Date of Patent: October 29, 2019
    Assignee: NOK CORPORATION
    Inventors: Hideaki Nagahamaya, Kokichi Hamamoto, Masayuki Tanida, Takehiro Nakagawa