Control device for a hydraulically operated load

US4325410A · kind A · utility

Inventors

• Wolfgang Bernhardt · Ditzingen, DE
• Heinz Kleinschmidt · Ditzingen, DE
• Joachim Heiser · Stuttgart, DE

Key dates

• Filing date: Dec 13, 1978
• Grant date: Apr 20, 1982
• Expiry date: Dec 13, 1998

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/87185
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

The control device for a hydraulically operated load includes a multiway piston valve defining a plurality of working chambers, a plurality of control chambers, a piston having axial and radial bores acting as first choke channels and a control collar cooperating with the control chambers to act as additional choke channels, a piston manometer valve biased by a spring and connected between a pump channel and a return flow channel. A control conduit including at least one choke is connectable via additional choke channels between the pump channel and the return flow channel and has a branch conduit leading to the spring-biased end of the manometer piston. The valve piston is displaceable from its neutral position into an intermediate control position in which in the range of the fine adjustment of the flow the pressure from the load is applied through the control conduit to the manometer piston to provide a load compensated control. In the end control position of the multiway piston the load compensated control is disconnected and maximum through-flow is attained.