Servo control valve for a hydraulically-actuated device
US5975139A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Jan 9, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86702
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A servo control valve includes a valve body that defines a high pressure passage, a low pressure passage and a flow passage. A valve member has a first pressure surface in opposition to a control pressure surface. The valve member is positioned in the valve body and moveable between a first position in which the high pressure passage is open to the flow passage, and a second position in which the low pressure passage is open to the flow passage. A pilot member is positioned in the valve body and is moveable between an up position in which the control pressure surface is exposed to pressure in the high pressure passage, and a down position in which the control pressure surface is exposed to pressure in the low pressure passage. A spring is operably positioned to bias a valve member toward one of its first position and its second position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.