Ultrasonic gas pressure measurement for inflators of vehicular airbag systems
US5869745A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1996 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Dec 20, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/101
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An inflator for an airbag system has a target mounted in the pressurized gas contained in the inflator. An ultrasonic transducer is mounted on an external surface of the inflator in alignment with the target. The transducer generates and receives reflected ultrasonic signals from the target. The time-of-flight of the signals which are dependent on the gas pressure are used to determine the gas pressure in the inflator. Temperature compensation is provided by fabricating the target of bimetallic material which changes the spacing of the target from the transducer with temperature or providing a temperature sensitive element, e.g. a thermocouple to electrically provide temperature compensation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.