Padlock with tamper-actuated audible and/or inaudible alarm
US4811578A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1985 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Jan 18, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T70/8216
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A padlock comprises a battery-powered, built-in alarm which operates when the padlock's shackle is severed or forced open. The battery and alarm can be tested by opening the lock with a key, rotating the short leg of the shackle away from the lock body and then depressing the shackle, or optionally, by depressing the short leg. The alarm is turned on in response to the momentary closing of a switch when one shackle leg moves outwardly upon severance or forcible opening. The alarm may be an audible signal or an inaudible signal transmitted as a radio wave to a remote receiver at which an audible or visible signal is actuated. The audible signal generated at the lock escapes from the lock body through sound ports. Both audible and inaudible signals may be generated at the lock simultaneously.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.