Hydraulic circuit for control of lip of vertically storing dock leveler
US4979253A · kind A · utility
12Cited by
4References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Jun 30, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65G69/2823
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
In a vertically storing dock leveler, more efficient, faster storage is enabled by providing a circuit which causes the lip of the leveler to maintain its position while the leveler platform is being raised. This position retention is in contrast to prior systems, in which raising the platform automatically caused pressure in the hydraulic cylinder controlling lip movement to drop, causing the lip to retract. By maintaining the lip position, lip extension can take less time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.