Anti-cavitation and pressure modulating relief valve for controlling hydraulic cylinders
US4114516A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1976 |
| Grant date | Sep 19, 1978 |
| Priority date | — |
| Expiry date | Oct 15, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2554
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A construction vehicle has a work implement, such as a bucket-carrying boom, pivotally mounted thereon to be raised and lowered by one or more double-acting hydraulic cylinders. A directional control valve is conditioned to selectively communicate pressurized fluid to the rod end of each cylinder, for example, through a check valve. When the fluid pressure in the rod end of the cylinder exceeds a predetermined level, a pilot signal will be communicated to a modulating valve which will open to closely control and modulate the flow of the fluid exhausted from the head end of the cylinder. A pilot relief valve is interconnected between the head end of the cylinder and the modulating valve to cooperate therewith to relieve excessive fluid pressures. The above system is duplicated for selectively pressurizing the head end of the cylinder and for exhausting the rod end thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.