Elevator door tampering protection system
US5443142A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 6, 1993 |
| Grant date | Aug 22, 1995 |
| Priority date | — |
| Expiry date | Dec 6, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B13/22
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
An automatic elevator system having car movement controls, door controls, a door operating mechanism for automatically opening and closing at least the car door and first switch contacts operable when the car and hoistway doors are closed to permit the car to move from a floor in combination with further switch contacts which are operable in accordance with the positions of the doors and which prevent the car from moving from a floor when the first switch contacts are operated before the further switch contacts to prevent movement of the car from a floor when the first switch contacts have been operated or shunted by unauthorized persons or by a short circuit and other means to protect against failures of other circuits operated by the first switch means and further switch means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.