Patents by Inventor Tatsuichi Yokoyama

Tatsuichi Yokoyama 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: 5580586
    Abstract: A die control speed rate conversion device for a powder mold press wherein the timing for oil release from a hydraulic circuit can be obtained by the angle signal (position signal) from a rotary encoder on the main axis of the press actuating synchronously with an upper punch, and the speed of descent of a die relative to an upper ram can be controlled at any rate ranging from 1:1 to 1:1/4 by a sevomotor controlled by the signal from a linear sensor detecting the movement of the upper ram.
    Type: Grant
    Filed: March 17, 1994
    Date of Patent: December 3, 1996
    Assignee: Tamagawa Machinery Co., Ltd.
    Inventor: Tatsuichi Yokoyama
  • Patent number: 5547360
    Abstract: The powder molding press reduces manufacturing and running costs by enabling rams to be driven with the necessary pressing force and ram speed despite small motor capacity. The molding press is provided with an encoder for detecting the rotating angle of a main shaft driving an upper ram, a control device for computing the quantities to be controlled of a lower ram against the detected rotational angle of the main saft, and for determining movements of the lower ram by applying data obtained from the computed results, and a motor for driving the lower ram under the control of the control device, and converting the rotational force of the motor to a compressive force and ram-driving speed suited for the molding press as well as for transmitting the force and speed to the lower ram.
    Type: Grant
    Filed: March 17, 1994
    Date of Patent: August 20, 1996
    Assignee: Tamagawa Machinery Co., Ltd.
    Inventor: Tatsuichi Yokoyama
  • Patent number: 4662234
    Abstract: A pair of non-circular gears having a fixed sum of the radius of the gears is used as transmission gears secured between a power shaft and a crank shaft. Each radius of the non-circular gears increases or decreases according to the required rotation. A powder feeding time in one cycle is prolonged by delaying the lowering velocity of an upper ram near the lowermost dead point of the upper ram which carries out the powder compacting and performing a quick return motion of the upper ram after a compacting zone.
    Type: Grant
    Filed: October 25, 1985
    Date of Patent: May 5, 1987
    Assignee: Tamagawa Machinery Co., Ltd.
    Inventors: Tatsuichi Yokoyama, Kazutami Takahashi