Hydraulic lift device for an attaching device
US6659192B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 2002 |
| Grant date | Dec 9, 2003 |
| Priority date | — |
| Expiry date | May 21, 2022 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01B59/066
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A hydraulic lift device for an attaching device of a tractor which has a hydraulic pressure supply device and a hydraulic tank, comprising for each of two lower steering arms, a double acting hydraulic cylinder having a cylinder housing, a piston rod, a piston with a piston-end piston area and a piston rod-end piston area, as well as a piston-end cylinder chamber and a piston rod-end cylinder chamber. The device further comprises a first switching valve, which has at least three switching positions and four ports. The first port represents a connection to the pressure supply device. The second port represents the connection to the hydraulic tank. The third port represents the connection to the piston-end cylinder chamber of the first hydraulic cylinder and the fourth port represents the connection to the piston rod-end cylinder chamber of the second hydraulic chamber. The piston rod-end cylinder chamber of the first hydraulic cylinder is connected via a line to the piston-end cylinder chamber of the second hydraulic cylinder. The piston rod-end piston area of the first hydraulic cylinder and the piston-end piston area of the second hydraulic cylinder have the same size or a predete…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.