Pressure alarm system for motor vehicle tires
US4890090A · kind A · utility
Inventor
Key dates
| Filing date | Jun 6, 1988 |
| Grant date | Dec 26, 1989 |
| Priority date | — |
| Expiry date | Jun 6, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60C23/0408
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pressure sensitive electrical switch consists of a housing in which two pressure chambers are formed. The pressure chambers are separated by a flexible diaphragm. The flexible diaphragm is made from electrical conductive material. Conductors extend into the housing to provide terminals which are spaced from the diaphragm when the pressure in the two chambers is substantially equal. When a pressure differential is established between the two chambers, the diaphragm may be deflected into contact with one or other of the terminals of the conductors. In use, the diaphgram is connected in an electrical circuit and each of the conductors is connected in an electrical circuit such that when contact is made between the diaphragm and one of the conductors, the electrical circuit will be complete. Because the diaphragm is at least partially permeable, this switch is intended to be used to monitor changes in pressure which occur between the two chambers over a relatively short period of time. This switch is used to advantage in a tire pressure warning system in which it serves to activate a transmitter which will transmit a signal indicating that the pressure in the tire has changed at an u…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.