Differential pressure regulator valve for a hydrostatic transmission control system
US3977424A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 1975 |
| Grant date | Aug 31, 1976 |
| Priority date | — |
| Expiry date | Apr 14, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7782
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An improved differential pressure regulator valve for a hydrostatic transmission control system wherein the valve regulates high fluid pressure versus low fluid pressure and produces a pressure differential that in turn controls the transmission. The regulator valve includes a valve body whose bore is in communication with both first and second sets of fluid inlet and outlet ports, with the valve bore containing a spool assembly that includes first and second cooperating spool members, with the second spool member being operable to control the fluid flow between the first inlet and outlet ports or the second inlet port and the first outlet port. Means, including a passage connecting the first outlet port with a spool port, fluidly unbalances the second spool member by applying the pressure of fluid in the first outlet port to one end of the second spool member in opposition to the biasing action of a regulating spring. Further means, including a passageway in the valve body that connects the second outlet port with the other end of the second spool member, fluidly unbalances the second spool member by applying the pressure of fluid in the second outlet port to the other end of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.