Lifting device
US9957982B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 2012 |
| Grant date | May 1, 2018 |
| Priority date | — |
| Expiry date | Nov 29, 2033 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/8606
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
An electromagnetic switching valve, for which the maximum opening is set to be small, is disposed on piping between a lift cylinder and a hydraulic pump motor. A pilot check valve, for which the maximum opening is set to be larger than the electromagnetic switching valve, is disposed on piping, different from the piping, between the lift cylinder and the hydraulic pump motor. In addition, during lowering operations, first, the electromagnetic switching valve is opened, and then after the same is opened, the pilot check valve is opened after a prescribed time has passed. Thus, the shock generated when lowering an object to be raised/lowered is reduced and a fork is operated quickly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.