Semi-active elevator hitch
US6216824A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1998 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Dec 24, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B7/08
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A system is provided for the semi-active damping of oscillations during vertical motion of an elevator car relative to a desired trajectory along a relatively lengthy elevator travel path. The elevator car is connected to a motor-controlled support rope in a manner allowing limited relative vertical motion therebetween. A soft spring and a controllable damping means are connected in parallel between the rope and the elevator car. The damping means may be a hydraulic piston and cylinder arrangement controlled via a variable orifice valve. The spring may be a gas-pressurized accumulator connected to the hydraulics of the damping means. A control system provides a motion command signal to control the motor for motion control and the variable orifice valve for damping oscillations. Full closure of the variable orifice valve effectively locks the damping means to maintain a position when the elevator car is braked, and a tension release control gradually releases any accumulated tension across the valve when the brake is released.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.