Patents by Inventor Itsuo Ishikawa

Itsuo Ishikawa 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: 5478092
    Abstract: A metal laminate gasket of the invention is used for an internal combustion engine formed of a cylinder head and a cylinder block. The gasket is basically formed of two metal plates laminated together. The gasket has a rectangular shape extending in a longitudinal direction, and two lateral side portions, each being defined between a lateral edge and a line linking centers of bolt holes located adjacent to the lateral edge. At least two edge support beads are integrally formed in at least one of the plates. The bead has a V shape opening toward the lateral edge. Thus, the lateral side portions are widely supported to thereby prevent deformation of the cylinder head and provide substantially equal tightening pressure around the entire cylinder bores.
    Type: Grant
    Filed: March 10, 1995
    Date of Patent: December 26, 1995
    Assignee: Ishikawa Gasket Co., Ltd.
    Inventors: Itsuo Ishikawa, Tsunekazu Udagawa
  • Patent number: 5427389
    Abstract: A metal laminate gasket of the invention is used for an internal combustion engine formed of a cylinder head and a cylinder block. The gasket is basically formed of two metal plates laminated together. The gasket has a rectangular shape, and includes a plurality of cylinder bores arranged in a longitudinal direction of the gasket, and a plurality of bolt holes arranged to surround the cylinder bores. The gasket has two lateral side portions, each being defined between a lateral edge and a line linking centers of bolt holes located adjacent to the lateral edge. At least two edge support beads are integrally formed on at least one of the plates. The edge support beads are formed at the lateral side portions to substantially completely support tightening pressure of the bolts applied to the lateral side portions. Thus, deformation of the cylinder head is prevented, and substantially equal tightening pressure can be formed around the entire cylinder bores.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: June 27, 1995
    Assignee: Ishikawa Gasket Co., Ltd.
    Inventors: Itsuo Ishikawa, Tsunekazu Udagawa
  • Patent number: 5375856
    Abstract: A protecting member of the invention is used for a gasket situated between two engine parts. The protecting member includes a spring member situated between the two engine parts and located around bolt. When the bolt is tightened, the spring member abuts against the engine parts and is compressed to provide predetermined pressure to the bolt through the engine parts. Thus, when an outward force applied to the bolt increase, an amount of the outward force exceeding the predetermined pressure, i.e. the tightening pressure, is only applied to the bolt to absorb a part of the outward force. When an inward force applied to the bolt decreases, the predetermined pressure of the spring member acts against the inward force applied to the bolt. Thus, the pressure changes to the gasket is reduced to prevent creep relaxation of sealing means of the gasket.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: December 27, 1994
    Assignee: Ishikawa Gasket Co., Ltd.
    Inventors: Itsuo Ishikawa, Tsunekazu Udagawa, Hisashi Yasui, Susumu Inamura
  • Patent number: 5316322
    Abstract: A metal plate for a gasket is provided with a plurality of beads around portions to be sealed. The beads intersect together to form an intersecting portion, which has an outer edge to surround the intersecting portion, a center portion in the center thereof, and a surrounding portion situated between the center portion and the outer edge. A cutting portion penetrating through the plate is formed at the center portion. When the metal plate is tightened, the cutting portion operates to disperse stress applied to the center portion of the intersecting portion. Therefore, equal surface pressure is formed on the intersecting portion as well as the beads.
    Type: Grant
    Filed: August 20, 1992
    Date of Patent: May 31, 1994
    Assignee: Ishikawa Gasket Co., Ltd.
    Inventors: Tsunekazu Udagawa, Itsuo Ishikawa
  • Patent number: 5277433
    Abstract: The metal laminate gasket of the invention is used for an internal combustion engine having a hole to be sealed. The gasket is formed of a plurality of metal plates for constituting the metal laminate gasket, and a device for defining the hole of the engine with a curved portion and a flange. Inside the curved portion around the hole, a wire ring, at least one bead and a hollow ring are situated. The hollow ring is arranged between the curved portion and the bead. The thickness of a metal plate for the hollow ring is adjusted so that the surface pressures on the wire ring and the bead are regulated by the hollow ring when the gasket is tightened.
    Type: Grant
    Filed: May 26, 1992
    Date of Patent: January 11, 1994
    Assignee: Ishikawa Gasket Co., Ltd.
    Inventors: Katsushiro Ishikawa, deceased, Itsuo Ishikawa
  • Patent number: 5221097
    Abstract: A sealing system is associated with an engine having two engine parts to be sealed, and includes a gasket situated between the engine parts. The engine parts include at least one annular groove around a hole to be sealed, and the gasket includes a bead extending outwardly from the gasket around the hole. The size o the bead is greater than that of the annular groove. When the gasket is tightened between the engine parts, the bead is compressed inside the groove and deforms to securely seal between the gasket and the engine parts. As a result, even if the engine part is slightly moved, the gasket can securely seal between the engine parts.
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: June 22, 1993
    Assignee: Ishikawa Gasket Co., Ltd.
    Inventors: Itsuo Ishikawa, Tsunekazu Udagawa
  • Patent number: 5170927
    Abstract: A metal plate for a gasket is provided with a plurality of beads around portions to be sealed. The beads intersect with each other to form an intersecting portion, which has a central portion, an outer portion outside the central upper portion and at least three side portion extending between side edges of the beads adjacent to each other. At least two side portions are curved to orient toward the intersecting portion and are located on or inside a part of an imaginary circular line. A radius of the imaginary circular line is at least twice as much as the width of the bead. Therefore, when the metal plate is tightened, the central portion is at first compressed to support the outer portion outside the central portion to thereby provide surface pressure substantially the same as that on the bead outside the intersecting portion.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: December 15, 1992
    Assignee: Ishikawa Gasket Co., Ltd.
    Inventors: Tsunekazu Udagawa, Yoshio Miyaoh, Itsuo Ishikawa