Method and means for detecting change in tire pressure

• US 4,149,140 A
• Filed: 05/23/1977
• Issued: 04/10/1979
• Est. Priority Date: 05/23/1977
• Status: Expired due to Term

• Current Assignee: Jon M. Miller, Ronald H. Evans
• Original Assignee: Jon M. Miller, Ronald H. Evans
• Inventors: Miller, Jon M., Evans, Ronald H.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/799,154
• Time in Patent Office: 687 Days
• Field of Search: 340/27 R, 340/58, 340/267 R, 340/267 C, 340/272, 340/285, 73/65, 73/88, 73/89, 73/90, 73/146, 73/146.2, 73/146.4, 73/146.5
• US Class Current: 340/443
• CPC Class Codes: B60C 23/06 Signalling devices actuated by deformation of the tyre , e.g. tyre mounted deformation sensors or indirect determination of tyre deformation based on wheel speed, wheel-centre to ground distance or inclination of wheel axle
• CPC Class Codes: B60G 2401/12 Strain gauge

Abstract

A novel method is disclosed for determining the change in tire pressure of a dual wheel tire by detecting a change in the axle housing moment arm supported by the wheel assembly. The preferred apparatus for carrying out the invention comprises one or more strain gauges affixed to the axle housing adjacent the tire assemblies and electronic means for measuring the strain occurring as a result of the underinflated tire.

Claims

1. Apparatus for detecting a change of pressure in one tire of a dual wheel assembly mounted to an axle housing by detecting a shift in the point of application of the resultant ground force transmitted by said dual wheel assembly to the axle housing, which comprises:

at least two strain gauges affixed to the axle housing adjacent said dual wheel assembly, but placed at separate distances therefrom;

means for detecting a change in resistance of each strain gauge; and

means for comparing the change in resistance of each strain gauge in such a manner so as to determine a change in the point of application of the resultant ground force on the axle housing.