Hydraulic control valve having a centering spring device
US5316044A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1992 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Dec 7, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8671
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Centering spring devices are useful in hydraulic control valves for returning the valve to the neutral position under both normal and abnormal operating conditions. Since the actuator moving the valve spool must work against the spring centering device, electrically actuated hydraulic valves have been limited to small sizes. The subject hydraulic control valve incorporates a centering spring device that can be controllably disabled so that the valve spool can be freely moved between the neutral and operating positions. In one embodiment, a centering spring is disabled by hydraulically moving the spring retainers toward each other to compress the spring with hydraulic fluid controlled by a solenoid valve. Maintaining the spring in a compressed condition permits the valve spool to be moved with a smaller actuator thereby making it feasible to control the valve position with an electrical actuator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.