Tire pressure sensor and sensing system
US4529961A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 1983 |
| Grant date | Jul 16, 1985 |
| Priority date | — |
| Expiry date | Oct 25, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60C23/0428
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A wheel-mounted tire pressure sensor employs a Bourdon tube which deforms in relation to tire pressure to drive a pivotal arm. Opposite ends of the arm support magnets which can close reed switches arrayed around the path of travel of the magnets. The reed switches are connected to passive resonators in such a way that for each of a number of regions of travel of the arm, a unique combination of resonators is activated. The resonators are connected to a wheel-mounted antenna which faces a stationary antenna. Frequency signal matching the frequencies of the resonator are sequentially broadcast by the stationary antenna to the resonators, which are excited to oscillate if activated by the corresponding switch or switches. The excited resonator broadcast their frequencies back to the stationary antenna and to a display unit which decodes the combination of resonator frequencies to display the corresponding tire pressure. An optional alarm unit includes a memory unit which holds maximum safe speed values for each of the detectable ranges of tire pressure. The sensed tire pressure is converted to the corresponding speed limit value which is then compared to the sensed vehicle speed. If …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.