Hydraulic leveling control system for a loader type vehicle
US6389953B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2000 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Nov 29, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/50545
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A hydraulic control system for controlling the orientation of a material handling unit on a lift boom. The control system includes a flow divider/combiner valve operative in a boom-raise, unit-leveling mode to pass a portion of the fluid displaced from the rod end of the boom cylinder to the base end of the unit cylinder, and operative in a boom-lower, unit-leveling mode, to combine the fluid stream displaced from the base end unit cylinder in a preset ratio with pressurized fluid, and pass the combined stream to the rod end of the boom cylinder. A modulating valve controls flow to and from the base end of the boom cylinder and is pilot actuated to inhibit descent of the boom until the pressure in the unit cylinder reaches a level at which the unit cylinder initiates levelling of the unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.