Patents by Inventor Haruo Hirakawa

Haruo Hirakawa 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: 6638036
    Abstract: A ventilating device capable of being easily assembled and disassembled, wherein, after setting a blower for exhaust and a blower for air supply on an electric motor (55), the electric motor is installed in an exhaust flow path (122) of a silencer box (100). The inside of the silencer box (100) is divided by partitions into the exhaust flow paths (122, 123) and air supply flow paths (132, 134) and sound absorbing material is installed on the wall surfaces of the air flow paths (122, 123, 132 and 134). Each blower aligns with each of the air flow paths when an air blow device is inserted, and an opening into which the air blow device is inserted is covered by a cover (150). The blowers can be assembled and disassembled from the side and the air blow devices can be inserted from the upper side.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: October 28, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Kobayashi, Tomoyuki Shibuya, Koji Okada, Takaaki Matsubara, Haruo Hirakawa
  • Patent number: 5263894
    Abstract: A ventilation control device for a high-speed train carriage is operable in conjunction with a ventilating blower. A deflectable spring flap is mounted to extend across the ventilation duct in the air flow path. When deflection of the flap reaches a threshold level corresponding to possible passenger discomfort, the flap operates a limit switch positioned behind it. This activates a driving solenoid to close a shutter which shuts off the flow through the duct. A timer holds the shutter closed for a predetermined period, after which it is re-opened. Use of a microprocessor-controlled continuous sensor and damper can thereby be avoided, while cutting out very large pressure fluctuations.
    Type: Grant
    Filed: February 7, 1992
    Date of Patent: November 23, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Haruo Hirakawa, Shinichiroo Ishikawa, Hiroshi Higaki, Atsushi Ikio, Masakazu Matsumoto
  • Patent number: 5137490
    Abstract: Ventilating equipment for railway rolling stock including a low-pressure supply air blower, a high-pressure supply air blower, a low-pressure exhaust air blower, and a high-pressure exhaust air blower. This ventilating equipment ventilates car interior during travel of a train outside of tunnels by the low-pressure supply air blower and the low-pressure exhaust air blower, and also ventilates the car interior during travel in tunnels by the high-pressure supply air blower and the high-pressure exhaust air blower. The high-pressure supply air blower and the high-pressure exhaust air blower produce a higher discharge pressure than a changing external pressure during a high-speed travel in tunnels, thereby preventing the propagation of an influence of the changing external pressure into the car interior.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: August 11, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Shinichirou Ishikawa, Toshiharu Matsuda, Haruo Hirakawa, Hiroshi Higaki, Atsushi Ikio, Masakazu Matsumoto