Pressure sensor and apparatus controlling and maintaining air-pressure in vehicle tires

摘要

A pressure sensor for an apparatus for controlling and maintaining air pressure in vehicle tires. The vehicle compressor outlet is connected through individual pneumatic tire circuits to each vehicle tire, via rotary couplings in the associated axles. Each tire circuit includes tubing for carrying air and monitoring tire pressure, the circuits supporting pressure sensors and electrovalves housed in a control unit in the dashboard of the vehicle. The sensor includes a piston which causes a shutter to move in and out of the light path of a LED/phototransistor device. When the sensor signals low tire pressure via a an electronic circuit, the corresponding electrovalve is energized for the compressor to pump the tire up back to its set pressure. The sensor further includes means for varying the set point.