Patents by Inventor Tokumi Tsugawa

Tokumi Tsugawa 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: 20020003221
    Abstract: In a main valve having a solenoid pilot operated valve a movable core and a hollow plunger are movably received in a sleeve extending from a pressure control chamber through an electromagnetic coil. Said plunger is structurally separated from a main valve member. A shaft is slidably received in said plunger. One end of said shaft carries a pilot valve member. A spring engages at said plunger and said shaft such that the free end of said shaft projects a predetermined length beyond an end face of the plunger. As long as said coil is de-energised, said spring separates said pilot valve member from a pilot valve seat. As soon as said coil is energised the plunger is attracted to the core, the shaft is displaced in relation to said plunger, and the pilot valve member projecting from the lower end of said plunger closes said pilot valve seat. Due to a then developing pressure difference said main valve is closed and kept in a closed state.
    Type: Application
    Filed: February 8, 2001
    Publication date: January 10, 2002
    Inventors: Katsumi Koyama, Tokumi Tsugawa, Shinji Saeki
  • Patent number: 6315266
    Abstract: In a silently operating pilot-operated flow regulating valve, a main valve element is not allowed to vibrate freely, e.g., in lateral direction in an opened state and cannot constitute a noise source because while the main valve element is brought into its open position, an urging force acts upon the main valve element so as to tilt it into vibration suppressing contact with the valve seat whereby vibration of the main valve element is restricted.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: November 13, 2001
    Assignee: TGK Co., Ltd.
    Inventors: Hisatoshi Hirota, Tokumi Tsugawa, Yusuke Inoue
  • Patent number: 6314753
    Abstract: To achieve a silent, noiseless operation supercooling degree-controlled expansion valve 10 wherein vibration of a valve element 14 induced by refrigerant flow changes is suppressed and a spring 18 presses valve element 14 in an oblique direction inclined with respect to an axial direction thereof against a surrounding member 12 to thereby restrict vibration of the valve element.
    Type: Grant
    Filed: June 6, 2000
    Date of Patent: November 13, 2001
    Assignee: TGK Co. Ltd.
    Inventors: Hisatoshi Hirota, Tokumi Tsugawa, Yusuke Inoue