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: 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
  • Publication number: 20140077459
    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: Application
    Filed: November 29, 2011
    Publication date: March 20, 2014
    Applicant: NOK CORPORATION
    Inventors: Yasunari Hamaya, Kokichi Hamamoto
  • Patent number: 8622397
    Abstract: An oil seal has a first seal member including a main lip and a first dust lip, and a second seal member installed in a machine outer side of the first seal member. The second seal member integrally has an end surface covering section covering an end surface section of a housing, an outer peripheral insertion section inserted from one side in an axial direction to an outer peripheral surface of the housing and engaged with a stepped engagement section in the outer peripheral surface of the housing so as to prevent the second seal member from coming off from the housing, an inner peripheral insertion section inserted to an inner peripheral surface of the shaft hole in the housing from one side in the axial direction, and a second dust lip slidably coming into close contact with the shaft in the machine outer side of the first dust lip.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: January 7, 2014
    Assignee: NOK Corporation
    Inventor: Kokichi Hamamoto
  • Patent number: 8573112
    Abstract: To cope with severe use conditions, a high-pressure fuel pump has a seal system (21) for separating/sealing fuel and lubricating oil, in an annular space between an axle reciprocating within the pump and a housing having the axle passing therethrough, wherein the seal system (21) consists of a combination of a fuel-side seal (31) for sealing fuel and lubricating-oil-side seal (41) for sealing lubricating oil, the fuel-side seal (31) is composed of a plastic-made seal ring (32) and a rubbery-elastomer-made O ring (33) for backup of the seal ring (32), the lubricating-oil-side seal (41) consists of a single body of single-lip-type oil seal (42) having a rubbery-elastomer-made seal lip (44) fitted to a metal ring (43) and arranged toward the lubricating oil side, and a distance between the fuel-side seal (31) and the lubricating-oil-side seal (41) is set to be larger than the reciprocating distance of the axle.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: November 5, 2013
    Assignees: NOK Corporation, Denso Corporation
    Inventors: Junichi Nakayama, Nobuyuki Eguchi, Tamio Inamura, Kokichi Hamamoto, Hiroshi Inoue
  • Publication number: 20130175764
    Abstract: An oil seal has a first seal member including a main lip and a first dust lip, and a second seal member installed in a machine outer side of the first seal member. The second seal member integrally has an end surface covering section covering an end surface section of a housing, an outer peripheral insertion section inserted from one side in an axial direction to an outer peripheral surface of the housing and engaged with a stepped engagement section in the outer peripheral surface of the housing so as to prevent the second seal member from coming off from the housing, an inner peripheral insertion section inserted to an inner peripheral surface of the shaft hole in the housing from one side in the axial direction, and a second dust lip slidably coming into close contact with the shaft in the machine outer side of the first dust lip.
    Type: Application
    Filed: March 17, 2011
    Publication date: July 11, 2013
    Applicant: NOK CORPORATION
    Inventor: Kokichi Hamamoto
  • Patent number: 7942423
    Abstract: A resin lip type seal (1) capable of increasing safety against rupture by reducing rigidity of a plate-like lip (4) bent around a tip point A of a approximately wedge-shaped recessed part (8) to reduce stress concentration at the point A, suppressing the lowering of sealability due to a reduction in creep of the lip, and increasing the follow-up capability of the lip to the eccentricity of its axis. Indentations are formed on the slidable contact surface (41) of the plate-like lip (4) or/and the anti-slidable contact surface (42) thereof. Indentations (7) are also formed on the sloped slidable contact surface (21) of the inner lip (2) of the seal. Then, the ratio of the portion of each of the slidable contact surfaces where the indentations (7) are formed is ½ or more of each of the surface areas of the slidable contact surfaces (21, 41, 42).
    Type: Grant
    Filed: May 24, 2006
    Date of Patent: May 17, 2011
    Assignee: NOK Corporation
    Inventors: Yosuke Kondo, Yasuaki Tanabe, Junichi Nakayama, Tamio Inamura, Koichi Mizunoya, Takeo Otani, Kokichi Hamamoto
  • Publication number: 20090302549
    Abstract: A resin lip type seal (1) capable of increasing safety against rupture by reducing the rigidity of a plate-like lip (4) bent about the tip point A of a roughly wedge-shaped recessed part (8) to reduce stress concentration at the point A, suppressing the lowering of sealability due to a reduction in the creep of the lip, and increasing the follow-up capability of the lip to the eccentricity of its axis. Slits are formed in the slidable contact surface (41) of the plate-like lip (4) or/and the anti-slidable contact surface (42) thereof. Slits (7) are also formed in the sloped slidable contact surface (21) of the inner lip (2) of the seal.
    Type: Application
    Filed: May 24, 2006
    Publication date: December 10, 2009
    Applicant: NOK CORPORATION
    Inventors: Yosuke Kondo, Yasuaki Tanabe, Junichi Nakayama, Tamio Inamura, Koichi Mizunoya, Takeo Otani, Kokichi Hamamoto
  • Publication number: 20090256315
    Abstract: To provide a sealing device in which a spring retainer portion integrally provided on a metal ring is neither worn away nor damaged, whereby it is made possible to achieve an easy production and a cost reduction, a sealing device is constructed by a cylindrical metal ring, a seal lip provided on one end of the metal ring and made of a rubber-like elastic material, a spring retainer portion provided on the other end of the metal ring, and a spring seated on the spring retainer portion, and the spring retainer portion is provided with an engaging means for preventing a rotating motion of the spring.
    Type: Application
    Filed: April 8, 2009
    Publication date: October 15, 2009
    Applicant: NOK CORPORATION
    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