Door hold open device
US5072973A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 1989 |
| Grant date | Dec 17, 1991 |
| Priority date | — |
| Expiry date | Oct 4, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T292/305
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A door hold open device for use with fire doors connected to a door closer unit. The hold open device has a latching means that automatically unlatches if the power supply drops below a predetermined threshold or a person attempts to disconnect the power supply. The device includes an electrical actuating means for unlatching the held open door. The actuating means allows a door to be latched open without constant current being supplied to the actuating means, so battery power is possible. The invention may be used with any door closer unit, does not require special wiring, and may include a self-contained power supply and an integral smoke detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.