Patents Assigned to Landmark West Ltd.
  • Percussion tool utilizing negative pressure
    Patent number: 4741404
    Abstract: A percussion tool has a frame in which a percussion element is fitted such that it can move axially by a small distance and in which a hammer for hitting the percussion element is supported axially movably. The hammer is moved toward a standby position by a supply of a high pressure thereto, while forming a negative pressure acting on the hammer to force it toward a percussion position and, in the standby position, the high pressure is released to allow the hammer to move toward the percussion position by the negative pressure.
    Type: Grant
    Filed: September 4, 1985
    Date of Patent: May 3, 1988
    Assignee: Landmark West Ltd.
    Inventor: Nobuo Oyama