Condition monitoring system (tire pressure)
US4450431A · kind A · utility
Inventor
Key dates
| Filing date | May 26, 1981 |
| Grant date | May 22, 1984 |
| Priority date | — |
| Expiry date | May 26, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60C23/0449
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A monitoring system for monitoring the condition in a vehicle wheel mounted tire. The system includes first and second LC circuits disposed within the tire and interconnected by a diode multiplier in series with a pressure switch. An exciter establishes an energetic electromagnetic field of a first frequency such that a first LC circuit is resonant at the same first frequency. This first frequency is converted into energy of a second frequency by a harmonic multiplier diode and is impressed upon a second LC circuit which is resonant at the second frequency, the second frequency being either an even or odd harmonic of the first (exciting) frequency. A receiver tuned to the second frequency interrogates the second LC circuit for presence of harmonic energy at the second frequency. A pressure switch opens when the tire pressure falls below a predetermined pressure which prevents activation of the second LC circuit so that the receiver will not sense the second frequency to which the second LC circuit is resonant, in which case there is provided an indication that the tire pressure is below the desired pressure. A scanner scans the receiver successively from one tire to another of a ve…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.