Twin post, telescoping jack hydraulic elevator system
US5597987A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1995 |
| Grant date | Jan 28, 1997 |
| Priority date | — |
| Expiry date | Jan 25, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B9/04
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A twin post, telescoping jack hydraulic elevator system has a pair of dynamic sensors to determine when the jacks are out of synchronization, by determining any relative differences in height between the two intermediate cylinders. The elevator also includes static sensors to determine if one or both intermediate cylinders are more than a predetermined distance away from their normal positions when the car is stopped at each floor. The controller actuates a resynchronization if the distance between the intermediate jacks exceeds a first threshold, and shuts down the elevator if the distance exceeds a second threshold or if resynchronization demands are issued too often. Preferably, the static sensors are positioned to detect the seal housing at the top of the intermediate cylinder, which projects outwardly from the cylinder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.