Restraining elevator car motion while the doors are open
US5321216A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1991 |
| Grant date | Jun 14, 1994 |
| Priority date | — |
| Expiry date | Apr 9, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B13/24
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
The invention is directed to a safety circuit which detects when the car is at least a predetermined distance away from a floor landing while a car door is open. The safety circuit, upon detection of this condition, activates a solenoid located on a safety governor of the elevator car and/or the counterweight, causing safeties to engage, precluding further motion of the car and/or counterweight. The safety circuit comprises the solenoid and a relay having a contact and a coil. Given means for energizing the coil when the elevator car drifts beyond a predetermined distance with a door open, the contact will close, providing power to the solenoid for actuation. The safety circuit preferably employs a relay which indicates whether the car door is open or closed, as well as relays which indicate whether various other system operational checks are satisfactory. To check the functionality of the components upon which the safety circuit relies, the preferred embodiment provides additional circuitry to check the functionality of the door relay and the operational check relay, as well as circuitry to check the electrical integrity of and the power connections to the solenoid. The safety cir…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.