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: 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
  • Publication number: 20090008883
    Abstract: A high-pressure fuel pump with seal system that is usable under the conditions of “high speed”, “high pressure” and “fuel resistance”. There is provided a high-pressure fuel pump comprising an axle capable of reciprocating motion in the pump and seal system (21) for separating/sealing of fuel and lubricating oil as sealing objects in a circular space within a housing having the axle passing therethrough, wherein the seal system (21) consists of a combination of fuel-side seal (31) for sealing of fuel and lubricating-oil-side seal (41) for sealing of lubricating oil. The fuel-side seal (31) is composed of plastic-made seal ring (32) and 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) wherein rubbery-elastomer-made seal lip (44) fitted to metal ring (43) is arranged so as to face the lubricating oil side.
    Type: Application
    Filed: December 14, 2006
    Publication date: January 8, 2009
    Applicant: DENSO CORPORATION
    Inventors: Junichi Nakayama, Nobuyuki Eguchi, Tamio Inamura, Kokichi Hamamoto, Hiroshi Inoue