Pulse Piston Position Responsive Patents (Class 417/387)
  • Diaphragm pump
    Patent number: 3957399
    Abstract: A diaphragm pump apparatus is disclosed, having a mechanically reciprocated piston driving a hydraulic fluid chamber and reciprocating a flexible diaphragm. The apparatus includes a spring-biased expansion volume connected to the hydraulic fluid chamber and a hydraulic fluid replenishing port that opens on predetermined conditions of pressure loading and piston stroke position.
    Type: Grant
    Filed: March 20, 1975
    Date of Patent: May 18, 1976
    Assignee: Graco Inc.
    Inventor: Bernard Siczek