Torsion spring powered door
US4804238A · kind A · utility
14Cited by
10References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1987 |
| Grant date | Feb 14, 1989 |
| Priority date | — |
| Expiry date | Jan 28, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE05Y2900/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An access door has a frame formed with longitudinally extending channels which receive a closure element for sliding therealong. A torsion spring secured to the frame and to the closure element maintains the closure element in an open or closed position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.