Low tire warning system
US4237728A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 30, 1979 |
| Grant date | Dec 9, 1980 |
| Priority date | — |
| Expiry date | Apr 30, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60G2204/113
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An abnormal tire profile indicating system comprising a telemetry unit mounted on each wheel of a vehicle and a central receiver. Each telemetry unit comprises a piezoelectric transducer which is deflected with each wheel revolution when the tire profile is low. Deflecting the transducer produces an electric pulse. The transducer pulses are accumulated on a charge storage capacitor to provide a power supply. When the level of charge on the capacitor reaches a predetermined level, a counter commences counting the transducer pulses. When a predetermined number of pulses are counted, the counter renders a transistor conductive, which transistor connects the power supply capacitor to an encoder and a transmitter. The encoder produces encoded signals and resets the counter after a predetermined number of encoder signals are produced. The central receiver receives the modulated radio signals from each of the telemetry units. The counter limits the transmitter to transmitting only after a sufficient number of low profiles are detected to assure reliable operation and only after a sufficient number of wheel revolutions to meet FCC periodicity of transmission requirements. The reset counter…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.