Patents by Inventor Masayasu Katada

Masayasu Katada 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).

  • Spring type ball emitting apparatus
    Patent number: 4368885
    Abstract: A tennis practicing machine is disclosed which has a rotating arm for periodically projecting a tennis ball towards a player. A spring connected to the rotating arm stores a rotating force which is periodically released as the rotating arm passes a predetermined point causing ball emission. A power source control system is provided which controls rotation of the motor such that in order to insure safe operation of the machine, when the machine is turned off a ball is emitted if the rotating arm is within a predetermined range near the point of ball emission. Accordingly accidental jarring or vibration of the machine does not cause accidental emission of a ball. Also, the system provides a delay for starting emission of the ball when the machine is first turned on, and furthermore circuitry is provided to maintain a constant time period of operation regardless of power main frequencies of 50 or 60 Hz.
    Type: Grant
    Filed: November 13, 1980
    Date of Patent: January 18, 1983
    Assignee: Sony Corporation
    Inventors: Masayasu Katada, Yuko Imai, Tsugio Hirabayashi