Pressure control valve
US4168721A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1977 |
| Grant date | Sep 25, 1979 |
| Priority date | — |
| Expiry date | Jun 16, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7925
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An improved pressure control valve which provides equal damping force in both directions of movement of the valve spool and which also provides negative feedback to partially negate fast transients leading to valve instability. The pressure control valve includes a valve body having an inlet chamber and an enlarged adjacent damping chamber. A valve spool is received within the chambers, the spool having a first portion and a second radially outwardly extending portion adjacent the first portion and disposed within the damping chamber. As the valve spool is shifted to an open position fluid will be expelled from the damping chamber through a first orifice, and as the valve spool returns towards its closed position fluid will be expelled through a second orifice, the orifices having cross-sectional areas proportionate to the volume of fluid being expelled so that equal damping will be obtained in either direction of movement of the valve spool. The valve spool is provided with an orifice passageway which permits fluid in the inlet chamber to be in communication with fluid in the damping chamber whereby transient peaks in the inlet may be transmitted to the damping chamber to provide …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.