Padlock with tamper alarm
US4556872A · kind A · utility
38Cited by
6References
36Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 18, 1983 |
| Grant date | Dec 3, 1985 |
| Priority date | — |
| Expiry date | Aug 18, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T70/8216
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A padlock contains a battery connected by electrical circuitry and switches to an alarm sounding device which sounds an alarm when someone attempts to force open or sever the lock shackle or when someone attempts to remove the battery in an unauthorized manner. A test signal of momentary duration is automatically sounded each time the lock is opened or closed in an authorized manner, and this indicates whether the alarm system is operative.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.