Method of determining a variable air pressure value of a pneumatic vehicle tire and indicating a pressure value

Claim 1

In a method of giving a vehicle driver the best possible information concerning vehicle tire pressure including factors of atmospheric pressure, inner temperature of the tire, and specific volume by determining a variable air pressure value of a pneumatic vehicle tire, based on transmitting of an information signal of high frequency modulated by a sensor and taken from a measured value emitter and conveyed to a measured value receiver for comparison between high frequency modulated by the sensor and a known high frequency at tire rated pressure stored in a storage means; evaluating this information signal, via evaluation means, including control circuit logic during the comparison at tire rated pressure with desired values at least for the air pressure of the pneumatic vehicle tire; determining a deviation value obtained by said evaluating during the comparison at tire rated pressure; and indicating an air pressure for the pneumatic vehicle tire based on the measured value; the improvement therewith further comprising in combination the steps of: comparing said information signal with several specific selectable desired value curves representing pressure ranges for specific values of atmospheric temperature and inner tire temperatures, each of which has a tolerable critical range extending along the curve indicative of acceptable pressure values for given temperatures and each of which is a mathematical function of an average atmospheric temperature that exists at any given time interval; after said comparing, determining at least one deviation value of said tire air pressure; assigning this deviation value to a specific tire air pressure as a mathematical function based on said desired value curve tolerance ranges; and then indicating at least the actual air pressure of said pneumatic vehicle tire and an indication of incorrect pressure being given when not within the tolerable critical range.