Valve having means for generating a wireless transmittable indicating signal in case of a pressure drop within vehicle tires

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;
• and
• an 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;
• and
• activates said transmitter means at least then, whenever a given ratio between the threshold value and the compare signal is outside upper and lower limits.