Patents by Inventor Mitsuhisa Kawamata

Mitsuhisa Kawamata 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: 5381584
    Abstract: A controlling apparatus controls a suction performance of a blower motor which is installed into a cleaner main body. The controlling apparatus increases the suction performance when a suction nozzle is operated and decreases the suction performance when the suction nozzle is stopped. Corresponding to a floor use suction nozzle and a crevice use suction nozzle, at a predetermined air flow amount range, the most suitable operation control being suited to a discriminated suction nozzle can carried out automatically. Plural kinds of the suction nozzles at an actual use scope are set beforehand. When the suction nozzle is exchanged the flow amount range is changed over and selected with a respective suction nozzle. Plural kinds of the suction nozzles are selected and changed over automatically according to the dimension of a change amount of an operation condition. A brushless direct motor is used as the blower motor and has a domain being operated at a chopper control duty of factor 100%.
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: January 17, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Jyoraku, Hisao Suka, Yoshitaro Ishii, Hisanori Toyoshima, Mitsuhisa Kawamata, Haruo Koharagi, Kazuo Tahara, Tunehiro Endo, Kunio Miyashita, Toshiyuki Ajima, Takeshi Abe, Atusi Hosokawa
  • Patent number: 5243732
    Abstract: In a vacuum cleaner, both static pressure H.sub.data and a variation width .DELTA.H in the static pressure appearing when a suction port is operated are detected from a pressure sensor provided at a rear side of a filter within a main body of the vacuum cleaner; a current variation width .DELTA.pbi appearing when the suction port is operated is detected from a current of a nozzel motor for driving a rotary brush stored in a power brush suction port; an air quantity at the suction port is calculated from the current, rotational speed of a fan motor and static pressure; command values are newly obtained by performing a fuzzy calculation with the variation width .DELTA.pbi, static-pressure command value Hcmd; the variation width .DELTA.H and the static-pressure command value Qcmd; the variation width .DELTA.pbi and static-pressure command value Hcmd; and also the variation width .DELTA.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: September 14, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Haruo Koharagi, Kazuo Tahara, Toshiyuki Ajima, Tsunehiro Endo, Hisao Suka, Mitsuhisa Kawamata, Fumio Jyoraku, Yoshitaro Ishii, Hisanori Toyoshima, Takeshi Abe, Atusi Hosokawa, Shoichi Ito, Motoo Futami, Kunio Miyashita
  • Patent number: 5027469
    Abstract: A vacuum cleaner comprising a fan motor disposed in a main body case thereof and having a motor with a permanent magnet stator or rotor, and a fan arranged to be rotated by the motor. A dust-collecting chamber collects dust suctioned into the main body case due to the rotation of the fan motor, and a dust-collecting filter causes the dust suctioned into the main body case to be caught in the dust-collecting chamber. A magnetic material adhesion preventing device is provided in a passage through which air flows due to rotation of the fan motor, with the magnetic material adhesion preventing device acting to prevent adhesion of fine dust composed of magnetic materials included in the air flow to a portion in the vicinity of the permanent magnet. As a result, adhesion of fine dust between the rotor and stator can be prevented thereby increasing the service life and the reliability of the vacuum cleaner.
    Type: Grant
    Filed: April 3, 1990
    Date of Patent: July 2, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Hisanori Toyoshima, Fumio Jyoraku, Mitsuhisa Kawamata, Yoshitaro Ishii, Jiro Arai