Pressure probe

US4951502A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Reiner Dorfler · Nuremberg, DE
• Gerhard Hettich · Roßtal, DE
• Hans-Dieter Schmid · Nuremberg, DE

Key dates

• Filing date: Aug 18, 1989
• Grant date: Aug 28, 1990
• Expiry date: Aug 18, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L19/02
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A pressure probe is suggested which serves to determine the air pressure in the interior of tubeless tires on motor vehicle wheels comprising a rim. The pressure probe (10) carries a substrate (26) in a front recess (31) of the probe housing (14) facing the tire interior, at least one sensing element (24) being arranged at the substrate (26) in the outer area on the side remote of the tire interior. In order to keep the air in the vehcile tire at a distance from the sensing elements (24) on the one hand, but transmit the air pressure to the latter without falsification on the other hand, a circumferentially extending cut out portion (36) in the housing area below the sensing elements (34) is filled with a non-conducting magnetic fluid (37), a permanent magnet (39) being arranged at the base (38) of the cut out portion (36), which permanent magnet (39) secures the magnetic fluid (37) for the purpose of covering the sensing elements (24) so as to be free of stresses (FIGURE).