Safety device to prevent accidental unwinding of a rolling shutter or rolling overhead door wound on a shaft
US4848522A · kind A · utility
10Cited by
6References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 2, 1987 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Dec 2, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE05Y2201/266
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A safety device for preventing accidental unrolling of a rolling shutter or overhead door comprising a cogwheel which has uniformly distributed on the circumference opening outward for containing radially movable tumblers, a cage which surrounds the cogwheel that contains an abutment in the form of a recess for the tumblers which are raised by the action of centrifugal force. Upon reaching a predetermined rotational speed, the tumblers engage an abutment in the cage and the cage acting as a brake is then driven by the cogwheel and slowed down by friction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.