Counterbalance valve
US5676169A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1996 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Jan 24, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2554
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The hydraulic counterbalance valve has a valve body with an inlet port, a cylinder port and a pilot port. The valve body has an interior chamber extending through the valve body which forms a check seat where the interior chamber narrows. The interior chamber is in communication with each port by a number of passages. A check valve is disposed in a first passageway between the interior chamber and the inlet port. A bypass passage exists to circumvent the check valve and provide communication between the interior chamber and the inlet port. A control spool is movably disposed in the interior chamber. The control spool has a pilot end, a sealing means, metered groove and a pilot check. The pilot check of the control spool forms a pilot check seal with the check seat of the interior chamber. A spool spring is disposed in the interior chamber and biases the control spool pilot check to seat against the pilot check seat of the interior chamber. The metered groove on the control spool act to permit metered flow from the chamber to the bypass passageway incident to hydraulic pressure at the pilot port sufficient to overcome the force of the spool spring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.