Patent · US Expired

Pressure drop signal generating valve cap for pneumatic tires

US5040562A · kind A · utility

41Cited by
11References
18Claims
0Family size

Inventor

Key dates

Filing dateSep 7, 1990
Grant dateAug 20, 1991
Priority date
Expiry dateSep 7, 2010

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/374
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

A valve cap adapted to be screwed onto the tire valve of a pneumatic tire generates a wireless transmissible pressure drop indication signal. The valve cap comprises a valve cap housing comprising a pressure chamber and a reference chamber. The non-blockable pressure chamber is admittable with the tire pressure to be controlled. The reference chamber is admitted with a desired pressure whenever the valve cap is screwed onto the tire valve. A signal generating means including transmitter means, power supply means and switching means is provided within said valve cap housing. The switching means comprises a conductor section fixedly arranged within the pressure chamber in a short distance to a rest position of a deflectable diaphragm. Any tire pressure drop will converge the diaphragm into the pressure chamber and will complete an electrical circuit whereupon a transmitter circuitry is supplied with voltage/current, and the transmitter means generates a pressure drop indicating signal of limited duration.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.