Protection system for automatically openable and closable door
US4057934A · kind A · utility
5Cited by
8References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1976 |
| Grant date | Nov 15, 1977 |
| Priority date | — |
| Expiry date | Oct 8, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE05Y2900/104
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A protection system for an automatically openable and closable door is provided in which an increase in the driving force produced when the door encounters with a blocking force in the opening operation as caused by some obstacles is detected to stop or reverse the door opening operation, thereby to suppress or reduce any possible accidents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.