Tire pressure sensor for motor vehicles

US4954677A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gunther Alberter · Wendelstein, DE
• Helmut Deeg · Winterthur, CH
• Gerhard Hettich · Roßtal, DE
• Klaus Neidhard · Wendelstein, DE
• Hans-Dieter Schmid · Nuremberg, DE
• Hans Schrumpf · Oberasbach, DE

Key dates

• Filing date: May 26, 1989
• Grant date: Sep 4, 1990
• Expiry date: May 26, 2009

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60C23/0408
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A tire pressure sensor to be fastened to a rim of a vehicle wheel for sensing an inflation pressure of a tire mounted on the rim, the tire pressure sensor comprising a reference pressure chamber having a gas filled reference pressure volume, an electrically conductive diaphragm for sealingly separating the reference pressure chamber at a tire interior, a sensor electric circuit, a contact pin located in the reference pressure chamber and cooperating with the electrically inductive diaphragm for closing the sensor electric circuit when the tire inflation pressure is at a predetermined value, and an additional pressure chamber communicating with the reference pressure chamber and deformable to change the reference pressure volume therein to thereby establish a predetermined reference pressure in the reference pressure chamber.