Patent ID: 6060983
Filing Date: 2000-05-09
Classification: B60C

Abstract:
An apparatus for alarming a decrease in internal air-pressure of a tire based on rotational information obtained from tires attached to a four-wheeled vehicle, the apparatus comprising:a rotational information detecting means for detecting rotational information of each tire;a storing means for storing the rotational information of each tire and relationships between relative speed ratios of right and left tires of different types of driving wheels which have been preliminarily set to be of normal air-pressure and driving force;a calculating and processing means for calculating determined values from rotational information of each tire; anda determining means for correcting relative speed ratios of right and left tires of different types of driving wheels at the time of actual running of the vehicle, the correcting being based on the relationship between the relative speed ratio of right and left tires of different types of driving wheels and driving force, and for determining a decrease in internal pressure of a tire; whereinthe determining means determines how relative speed ratios of right and left tires vary according to driving force.