Acoustically coupled burglar alarm system
US3973250A · kind A · utility
5Cited by
7References
5Claims
0Family size
Inventor
Key dates
| Filing date | Nov 12, 1974 |
| Grant date | Aug 3, 1976 |
| Priority date | — |
| Expiry date | Nov 12, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/08
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An ultrasonic whistle is mounted together with a pin on a window or door so that movement of the window or door causes relative movement between the whistle and pin. Such movement releases compressed gas from a container which activates the whistle. A central monitor in the building detects the output of the whistle and provides an output to activate alerting devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.