Dual sensor electromagnetic door lock system
US4893852A · kind A · utility
27Cited by
9References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1989 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Jan 17, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T292/11
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An electromagnetic lock which mounts at the top of a door frame and magnetically bonds with an armature employs both an ultrasonic sensor and a passive infrared sensor to detect the approach of an individual at the doorway. Both the ultrasonic sensor and the passive infrared detector have fan-shaped sensing regions which are positioned forwardly from the doorway. Upon detection of an individual approaching the doorway, the lock is capable of automatically releasing to allow egress through the doorway.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.