Brake booster

US4934248A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Andreas Abbing · Ludwigsburg, DE
• Hannes Bertling · Leinfelden, DE
• Georg Kehl · Stuttgart, DE
• Heinz Siegel · Stuttgart, DE

Key dates

• Filing date: Apr 28, 1989
• Grant date: Jun 19, 1990
• Expiry date: Apr 28, 2009

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60T13/144
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A brake booster in a housing, having a servo piston slidably supported in the housing and having a piston rod protruding into the housing for transmitting a brake force. In the servo piston, a work chamber is provided for receiving brake fluid drawn after the opening of a valve from a reservoir or supply container and pumped via a pump or the like. The work chamber also communicates via a further valve or the like with a return line to the supply container. To improve valve closing and to shorten the idle travel, the valve preceding the work chamber and arranged for the admission of the brake fluid is embodied by a valve bushing in a blind bore of the servo piston and by a spring-loaded closing element, such as a ball. The valve bushing is disposed between the piston rod and the ball and is traversed by a pin or the like, capable of being acted upon by the piston rod, for lifting the ball from its valve seat.