Virtually active elevator hitch
US6065569A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 24, 1998 |
| Grant date | May 23, 2000 |
| Priority date | — |
| Expiry date | Dec 24, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B1/42
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A virtually active hitch system is provided for the damping of vertical oscillations of an elevator car during a semi-active hitch mode of operation along a relatively lengthy elevator travel path and for load leveling the elevator car during an active mode when the elevator is braked. The virtually active hitch stores energy derived from the elevator motor during the semi-active mode, and utilizes that stored energy during the active mode to actively adjust the positioning of the elevator car, as might result from load changes. The hitch assembly may advantageously use hydraulic piston and cylinder means to adjust, or impede adjustment of, a limited hitch gap between a support rope and the elevator car. The hydraulic circuit associated with the piston and cylinder may include a variable orifice valve to control damping action and a pair of accumulators controlled via a switching network to selectively store and release energy and to also serve as a spring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.