×

Detecting a deflated tire by comparing angular velocity data of all wheels, a data table, and the directly-measured pressure of a single tire

  • US 5,483,220 A
  • Filed: 12/21/1993
  • Issued: 01/09/1996
  • Est. Priority Date: 12/24/1992
  • Status: Expired due to Term
First Claim
Patent Images

1. A device for detecting a deflation condition of a tire mounted on a wheel of a vehicle comprising:

  • angular velocity detecting means for detecting an angular velocity of each wheel,angular velocity signal producing means for producing signals proportional to the detected angular velocities,pneumatic pressure detecting means for directly detecting the pneumatic pressure of only one wheel of the vehicle, defined as the detected wheel,pneumatic pressure signal producing means for producing a signal proportional to the obtained pneumatic pressure,arithmetic processing means for arithmetically processing the signals from the angular velocity signal producing means and the pneumatic pressure signal producing means, wherein, with respect to the detected wheel, the arithmetic processing meansoperates a device which warns of a deflation condition of the detected wheel when the difference between the detected pneumatic pressure and a predetermined normal pneumatic pressure is not less than 0.3 kgf/cm2 ; and

    wherein with respect to the other wheels, when the detected pneumatic pressure is normal, the arithmetic processing means obtains ratios of respective angular velocities of each of the other wheels to an angular velocity of the detected wheel,compares the obtained ratios with ratios in a table of wheel angular velocity ratios under normal conditions on the basis of the angular velocity of the detected wheel,compares the angular velocity of each of the other wheels and an average value of angular velocities of all the wheels, andoperates a device which warns of the deflation condition of one of the other wheels when the difference between the compared ratios ranges from 0.05% to 0.60% or when the difference between the angular velocity of one of the other wheels and an average value of angular velocities of all the wheels ranges from 0.05% to 0.60%.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×