Importance

Loading Importance Indicators...

Abstract

A pneumatic pressure sensor switch device for giving a warning signal if a pneumatic vehicle tire has too low pressure has a gas-filled chamber, separated from the inflation space in the tire by a first flexible diaphragm, and having another, second flexible diaphragm as its opposite wall, which has electrical contact means cooperating with a stationary contact point in the sensor. If the tire pressure is not too low, the first diaphragm is moved by the tire pressure to compress the gas in the said gas-filled chamber, which gas moves the second diaphragm out of contact with the stationary contact point. If the tire pressure drops below a certain value, the second diaphragm closes an electric circuit with battery and transmitter, so that a signal is given to the outside. There may be a third diaphragm bordering another closed chamber and by an electric series-connection to said second diaphragm, avoiding that a signal is given at atmospheric outside pressure, so as not to lose energy during storage or absence of a tire on the wheel. There may be two or more such sensors giving a signal at different pressures and they may be embodied so as to give signals in the correct pressure range in tires having two different inflation pressures in view of different loads of the vehicle or adaptation to switching tires from front to back of the vehicle.

Loading the Abstract Image...

First Claim