Patents by Inventor Masafumi Ohkuma

Masafumi Ohkuma 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).

  • DC motor unit with a rotational speed detector
    Patent number: 5124602
    Abstract: A d.c. motor unit with a rotational speed detector comprising a d.c. motor (1) having an output end and an idle end, and a rotational speed detector (14) water-tightly attached to the motor output end. The d.c. motor (1) comprises a motor frame (2) including an output end and an idle end, a mounting bracket (9) attached to the output end of the motor frame (2) and a rotary shaft (4) having an idle end rotatably supported by the motor frame (2) and an output end rotatably supported by and extending outwardly through the mounting bracket (9). The rotational speed detector (14) comprises a rotary portion mounted on the output end of the rotary shaft (4) and a stationary portion mounted to the mounting bracket at the output end of the motor frame (2). The rotational speed detector (14) comprises a substantially elastic permanent magnet plate (20) for generating a magnetic flux (.phi.
    Type: Grant
    Filed: April 9, 1991
    Date of Patent: June 23, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshihiko Nishimura, Masafumi Ohkuma, Teruaki Matsunaga