Control system for a hydraulic load

US4429619A · kind A · utility

Inventors

• Volkmar Leutner · Friolzheim, DE
• Berthold Pfuhl · Markgröningen, DE

Key dates

• Filing date: Apr 4, 1980
• Grant date: Feb 7, 1984
• Expiry date: Apr 4, 2000

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/2562
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A hydraulic control circuit for a cylinder-and-piston unit includes a relatively small electrohydraulically operated servo-control valve, a main pressure conduit including a measuring throttle, an auxiliary control valve cooperating with an additional pressure conduit connected parallel to the main pressure conduit to branch the pressure fluid in response to a predetermined level of pressure difference occurring across the measuring throttle. In this manner the servo-control valve can control a system of pressure fluid which is substantially larger than the nominal flow rate of the servo-control valve.