초록 ▼

A valve which includes signal generating means generate a signal representing a pressure drop within a vehicle tire. The valve includes an absolute pressure sensor coupled to measure the pressure within the tire. A microprocessor is provided which upon activation following operation of the valve sto

A valve which includes signal generating means generate a signal representing a pressure drop within a vehicle tire. The valve includes an absolute pressure sensor coupled to measure the pressure within the tire. A microprocessor is provided which upon activation following operation of the valve stores a value of the electric pressure signal from the pressure sensor in a memory. During operation of the vehicle, the stored reference electric pressure signal is compared with periodic measurements of pressure within the tire. The transmitter is activated at periodic intervals, whenever a given ratio between the compared values and a threshold value exceeds an upper or lower limit. The system is activated by a acceleration sensor which can detect when the vehicle is moving, thus avoiding power consumption stopped.

대표청구항 ▼

[ What is claimed is:] [1.] A valve having signal generating means for generating a wireless transmittable indicating signal in response to a pressure drop within a vehicle tire, wherein the valve comprises a valve spud and a valve stem extending from said valve spud which provides a valve means whi

[ What is claimed is:] [1.] A valve having signal generating means for generating a wireless transmittable indicating signal in response to a pressure drop within a vehicle tire, wherein the valve comprises a valve spud and a valve stem extending from said valve spud which provides a valve means which opens and closes during pressurization of said tire, said signal generating means mounted adjacent said valve spud comprising at least:an absolute-pressure sensor being coupled to the pressure within the tire and generating an electric pressure signal in accordance with the pressure within the tire;an electronic storage means;a transmitter means for telemetric transmission of an indicating signal in case of a pressure drop;a microprocessor including an arithmetic-logic unit; andan activating means coupled to said valve means for enabling the absolute-pressure sensor to generate an electric pressure signal corresponding to the actually prevailing tire pressure in response to operation of said valve means;said electric pressure signal being stored into the electronic storage means after each operation of said valve means and is available as a reference pressure signal;and wherein the arithmetic-logic unit:compares an electric pressure signal generated by said absolute-pressure means with said stored reference pressure signal and generates a compare signal;refers said compare signal to a given threshold value; andactivates said transmitter means at least then, whenever a given ratio between the threshold value and the compare signal is outside upper and lower limits.