Door activity monitoring apparatus
US4976215A · kind A · utility
1Cited by
5References
3Claims
0Family size
Inventors
Key dates
| Filing date | Apr 10, 1989 |
| Grant date | Dec 11, 1990 |
| Priority date | — |
| Expiry date | Apr 10, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B5/24
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A door activity monitoring apparatus (10) including a pivoted signal unit (11) that is mounted on a door jamb (100) and has a magnetically attractive indicator member (14) which cooperates with a magnetic keeper unit (12) that is secured to the door (103) to provide a visual signal indicative that the door (103) has been moved relative to the door jamb (100).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.