Hydraulic system

US4105041A · kind A · utility

Assignee

• Fichtel & Sachs · DE

Inventor

• Ludwig Axthammer · Diez, DE

Key dates

• Filing date: Aug 3, 1976
• Grant date: Aug 8, 1978
• Expiry date: Aug 3, 1996

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/2627
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A hydraulic system suitable for supplying fluid under pressure to the brakes and other elements of an automotive vehicle includes a valve casing formed with a first port, normally connected to a pump, a second port normally connected to a fluid storage vessel and the vehicle element to be supplied, and a third port leading to a sump. A valve slide moves in the casing and defines therewith a conduit. The conduit connects the first and third ports in a first slide position and is closed in a second slide position. A spring-loaded check valve connects the first and second ports only when the fluid pressure in the first port is higher than in the second port. A spring permanently biases the valve slide toward the second position while the fluid pressure in the second port tends to move the slide toward the first position. The biasing force of the spring decreases during movement of the valve slide from the second toward the first position.