Vacuum brake power booster

US5293808A · kind A · utility

Assignee

• Alfred Teves GmbH · DE

Inventors

• Manfred Rueffer · Pocking, DE
• Ralf Jakobi · Flörsheim, DE
• Jürgen Bauer · Pocking, DE
• Peter Kraft · Kassel, DE

Key dates

• Filing date: Jun 12, 1992
• Grant date: Mar 15, 1994
• Expiry date: Jun 12, 2012

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60T13/57
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A vacuum brake power booster and a process is disclosed in which a precise adjustment of the power boost startup characteristic is achieved. The adjustment is carried out as a final step in the manufacture of the booster adjusting the distance between the valve piston and an elastic reaction distance. During adjustment, the vacuum brake power booster has a vacuum applied. A pre-established input force is exerted on the piston rod while simultaneously measuring the output force exerted by the push rod, and the axial length of the valve piston is modified until the measured output force is within a pre-established range. The adjustment is carried out by modifying the length of a two piece valve piston or by temporarily extending a rod within the valve piston until a correct output force is reached and thereafter removing the rod and inserting a transmission pin of a length determined by the extent of travel of the rod at the point at which the desired output force was attained.