Patents by Inventor Tomokazu Nakazawa

Tomokazu Nakazawa 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: 7021901
    Abstract: An object of the invention is to provide a variable displacement compressor which is capable of using a solenoid control valve which does not require a large solenoid force. The compressor is configured such that an electromagnetic proportional flow rate control valve is arranged in a refrigerant passage leading from a discharge chamber to a condenser, that a differential pressure regulating valve is arranged in a refrigerant passage leading from the discharge chamber to a crank chamber, and that a fixed orifice is arranged in a refrigerant passage leading from the crank chamber to a suction chamber, whereby the differential pressure regulating valve senses a differential pressure Pd, Pd? generated across the electromagnetic proportional flow rate control valve, for control of pressure introduced into the crank chamber.
    Type: Grant
    Filed: November 5, 2003
    Date of Patent: April 4, 2006
    Assignee: TGK Co., Ltd.
    Inventors: Hisatoshi Hirota, Tomokazu Nakazawa
  • Publication number: 20040091369
    Abstract: An object of the invention is to provide a variable displacement compressor which is capable of using a solenoid control valve which does not require a large solenoid force. The compressor is configured such that an electromagnetic proportional flow rate control valve is arranged in a refrigerant passage leading from a discharge chamber to a condenser, that a differential pressure regulating valve is arranged in a refrigerant passage leading from the discharge chamber to a crank chamber, and that a fixed orifice is arranged in a refrigerant passage leading from the crank chamber to a suction chamber, whereby the differential pressure regulating valve senses a differential pressure Pd, Pd′ generated across the electromagnetic proportional flow rate control valve, for control of pressure introduced into the crank chamber.
    Type: Application
    Filed: November 5, 2003
    Publication date: May 13, 2004
    Applicant: TGK CO., LTD
    Inventors: Hisatoshi Hirota, Tomokazu Nakazawa
  • Publication number: 20040074245
    Abstract: To provide a capacity control valve for a variable displacement compressor, which is capable of returning lubricating oil contained in refrigerant into a crank chamber efficiently by a simple construction.
    Type: Application
    Filed: September 30, 2003
    Publication date: April 22, 2004
    Applicant: TGK CO., LTD.
    Inventor: Tomokazu Nakazawa
  • Patent number: 6662581
    Abstract: A displacement control valve that performs transition between operating capacities in a reduced time period. A valve element for introducing refrigerant from a discharge chamber into a pressure-regulating chamber after reducing discharge pressure Pd of the refrigerant to pressure Pc1, and a valve element for introducing refrigerant having pressure Pc2 from the pressure-regulating chamber into a suction chamber under suction pressure Ps are configured to open and close in an interlocked fashion, and a displacement control valve is comprised of the valve elements and a solenoid section that applies to a solenoid force corresponding to a predetermined differential pressure to these valve elements.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: December 16, 2003
    Assignee: TGK Co., Ltd.
    Inventors: Hisatoshi Hirota, Tomokazu Nakazawa
  • Patent number: 6662582
    Abstract: A displacement control valve which is capable of shortening a time period for transition in operating displacement, and operating without necessitating a large solenoid force even if the size of the valve is increased so as to increase the amount of refrigerant. A differential pressure-sensing section is separated from a valve section, and caused to sense the differential pressure by a small-diameter piston rod such that even a small-sized solenoid section can set a differential pressure. A valve element, which is formed to have a larger diameter than that of the piston rod to increase the amount of refrigerant, is configured to operate as a member formed in one piece with a shaft.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: December 16, 2003
    Assignee: TGK Co., Ltd.
    Inventors: Hisatoshi Hirota, Tomokazu Nakazawa
  • Publication number: 20030024257
    Abstract: The object of the invention is to provide a displacement control valve which is capable of shortening a time period for transition in operating displacement, and operating without necessitating a large solenoid force even if the size of the valve is increased so as to increase the amount of refrigerant. A differential pressure-sensing section is separated from a valve section, and caused to sense the differential pressure by a small-diameter piston rod such that even a small-sized solenoid section can set a differential pressure. A valve element, which is formed to have a larger diameter than that of the piston rod to increase the amount of refrigerant, is configured to operate as a member formed in one piece with a shaft.
    Type: Application
    Filed: July 19, 2002
    Publication date: February 6, 2003
    Applicant: TGK Co., Ltd.
    Inventors: Hisatoshi Hirota, Tomokazu Nakazawa
  • Publication number: 20030019226
    Abstract: It is an object to provide a displacement control valve that performs transition between operating capacities in a reduced time period.
    Type: Application
    Filed: July 18, 2002
    Publication date: January 30, 2003
    Applicant: TGK Co., Ltd.
    Inventors: Hisatoshi Hirota, Tomokazu Nakazawa