Safety system for closing doors
US4753323A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1987 |
| Grant date | Jun 28, 1988 |
| Priority date | — |
| Expiry date | May 26, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE05Y2900/104
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A capacitive safety system for controlling a door, e.g. an elevator door, so as to automatically avoid obstacles, employs electronic control for antennas operating as capacitive measuring elements for establishing shield voltages of identical phase on the antennas and on shield voltage antennas to counteract ambient capacity variations. In order to improve the operation and safety of the elevator door, the elevator shaft door, which closes simultaneously with the elevator door, is provided with similar capacitive measuring antennas and electronic controls as the elevator door, as well as with similar shield voltage antennas, which operate on a shield voltage having the same phase as that of the elevator door. Operation of the elevator shaft door and the elevator door with identical phases is effected by means of a wireless shield voltage transfer unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.