Patents by Inventor Hirokazu Kawakami

Hirokazu Kawakami 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: 6295264
    Abstract: An optical disk device has a spindle motor for rotating a disk, an optical head for writing or retrieving data on the disk, a cooling fan for cooling the device, and a motor for rotating the cooling fan. In one embodiment, the device further has a controller for outputting a control signal for controlling the speed of the spindle motor and the cooling fan. In that embodiment, the device further has first and second drivers for adjusting the current supplied to the spindle motor and the cooling fan motor. In another embodiment, the cooling fan is rotated using the spindle motor, transferring power with a gear and a shaft. In both embodiments, the cooling fan rotates in proportion to, e.g., 1.25 times, the speed of the spindle motor.
    Type: Grant
    Filed: July 16, 1999
    Date of Patent: September 25, 2001
    Assignee: NEC Corporation
    Inventor: Hirokazu Kawakami
  • Patent number: 6008992
    Abstract: The present invention provides a locking device having a simplified and energy saving configuration that assures to prevent an unintentional erroneous removal of a container case in operation mode from an apparatus main body. The locking device comprises: first engagement device which is an engagement hole 10 provided in an electronic apparatus main body 1; and second engagement device provided in a disc container case 2 that is inserted into and removed from the electronic apparatus through an opening 1a of the electronic apparatus main body 1. The second engagement device includes a movable engagement piece 21 constituted to be movable toward the engagement hole 10 and a movement urging mechanism 23 for urging this movable engagement piece 21. This movement urging mechanism 23 consists of a working member 23A made from a shape-memory alloy that change its distance from a first end to a second end when subjected to a heat; and a fixed base 24 for fixing the second end of the working member 23A.
    Type: Grant
    Filed: January 21, 1999
    Date of Patent: December 28, 1999
    Assignee: NEC Corporation
    Inventor: Hirokazu Kawakami
  • Patent number: 5722818
    Abstract: A hermetically sealed type compressor having a valve seat plate equipped with a plurality of suction holes to effectively suck a refrigerant into a cylinder and capable of preventing the breakage of the valve seat plate coming from the opening and closing operations of a suction reed valve. A partition 50 between adjacent suction holes in the valve seat plate 15 is made to have a constant dimension, thus maintaining a given strength of the partition section and preventing the breakage of the partition 50 coming from the opening and closing movements of the suction reed valve. In addition, in the valve seat plate 15, a cavity 22 or a groove 37 is formed to define a low-pressure space 36 communicating with the plurality of suction holes 24, 25, thereby reducing the suction resistance.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: March 3, 1998
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Michio Ohta, Hirokazu Kawakami, Shuji Kawashima
  • Patent number: 5328338
    Abstract: A hermetically sealed electric motor compressor, comprising a hermetically sealed casing, a reciprocating compressor unit mounted within the casing and compressing a working fluid, the compressor unit having a first discharge passageway, a valve assembly mounted within the casing and opening and closing the first discharge passageway, the valve assembly having a second discharge passageway, a discharge port mounted to the second discharge passageway within the casing and including a muffler. The muffler defines a plurality of resonance chambers. The discharge port includes a base plate having a projection. The valve assembly includes a reed valve assembly including a reed valve and a valve backer mounted behind the reed valve.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: July 12, 1994
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yutaka Hirano, Hirokazu Kawakami, Ryuji Watanabe, Kiyoshi Tanaka, Hiroshi Takagi
  • Patent number: 4918806
    Abstract: In a method for manufacturing a piston a metal piston is prepared which has a skirt tapered towards the bottom end to such an extent that a diameter of the metal piston becomes uniform after a heat treating step. The metal piston is heat treated in a gas containing nitrogen and carbon to form a nitride film layer on the outer surface of the piston and to transform the skirt.
    Type: Grant
    Filed: February 14, 1989
    Date of Patent: April 24, 1990
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Ryuji Watanabe, Motohiko Kosano, Hirokazu Kawakami
  • Patent number: 4913001
    Abstract: A piston assembly for compressors wherein a piston is connected to a crankshaft by a connecting rod having a ball at its one end, the ball being, with the rear portion thereof, joined to the piston by clamping a clamp portion provided on the piston, while the front portion of the ball is in contact with a ball seat formed in the inner portion of the piston, the crankshaft being formed at its upper end with an oil outlet for scattering an oil upon ejection therefrom, the piston assembly being characterized in that a plurality of holes are formed in the clamp portion, the piston having a skirt portion formed with a plurality of holes opposed to the respective holes.
    Type: Grant
    Filed: February 15, 1989
    Date of Patent: April 3, 1990
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Ryuji Watanabe, Kiyoshi Tanaka, Hirokazu Kawakami
  • Patent number: 4573880
    Abstract: A hermetically sealed motor compressor for use in a small-size refrigerating machine, refrigerator, freezer and the like has a compressor on which is mounted a silencer comprising in combination a suction muffler of thermal insulating and a discharge muffler made of formed metal plates. The suction muffler has an suction port disposed near the open end of a suction coupling fixed to a sealed casing, and also has an connection pipe connected to a compressor cylinder and having a distal end fitted directly in a hole defined in an head plate which is mounted on the head of the cylinder. A refrigerant gas as it is introduced from the suction coupling into the sealed casing can be drawn into the cylinder through the suction port, the suction muffler and the connection pipe to minimize heat transfer to the suction gas, so that the compressor can increase its volumetric efficiency.
    Type: Grant
    Filed: March 4, 1985
    Date of Patent: March 4, 1986
    Assignees: Sanyo Electric Co., Ltd., Tokyo Sanyo Electric Co., Ltd.
    Inventors: Yutaka Hirano, Hirokazu Kawakami, Masaaki Tanaami, Motohiko Kosano, Hiroshi Takagi, Yoshio Ishiai, Ituo Iwahashi