Dual circuit brake valve system

US5380073A · kind A · utility

Assignee

• WABCO Standard GmbH · DE

Inventors

• Peter Bartscher · Hannover, DE
• Gerhard Martini · Gehrden, DE
• Wolfgang D. Pohl · Adliswil, CH
• Jurgen Sandmann · Wennigsen (Deister), DE

Key dates

• Filing date: Sep 21, 1993
• Grant date: Jan 10, 1995
• Expiry date: Sep 21, 2013

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60T15/045
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A dual circuit brake valve system comprises first and second brake circuits, first and second combined inlet and outlet valves through which first and second braking pressures respectively are delivered to said first and second brake circuits, and first and second pistons which actuate the first and second combined inlet and outlet valves respectively. The second piston is actuated by the first braking pressure which serves as a control pressure therefor. To achieve simultaneous actuation of the first and second combined inlet and outlet valves, a compression spring is installed between the first and second pistons and mechanically connects these to each other. Thereby, a pressure difference of .DELTA.p between the pressure in the first brake circuit and the pressure in the second brake circuit, which approaches zero, is achieved. In order to be able to increase the pressure difference .DELTA.p in the two brake circuits, a third piston is provided between the first and second pistons. The third piston is subjected to braking pressure from the first brake circuit in such a manner that the third piston compresses the compression spring when a predetermined level of pressure is reache…