Patents Assigned to DEPA Gesellschaft fur Verfahrenstecnik mit beschrankter Haftung
  • Patent number: 5174731
    Abstract: A method and an apparatus for control of the movement of a control piston an air control valve for a compressed air-operated double diaphragm pump, wherein the control piston is moved between the end positions in a control cylinder having inlet bores and outlet bores for the compressed air. The control piston is adjusted by a control medium. The method includes initially maintaining the control piston in an end position by a holding device against the pressure of the control medium for a predetermined period of time or until a counterpressure reaches a predetermined pressure level. Subsequently, the control piston is moved with a pushing force which is always greater than the maximum frictional forces. The holding device operates independently of the movement of the pump diaphragm, preferably using elastically, magnetically, or electromagnetically operating structural elements. The control cylinder includes separate connections for a control medium for moving the control piston.
    Type: Grant
    Filed: December 28, 1989
    Date of Patent: December 29, 1992
    Assignee: DEPA Gesellschaft fur Verfahrenstecnik mit beschrankter Haftung
    Inventor: Gerardus Korver