Power transmission
US4099541A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1976 |
| Grant date | Jul 11, 1978 |
| Priority date | — |
| Expiry date | Nov 12, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/87241
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A directional valve assembly for use in hydraulic power systems such as are used on fork lift trucks has a plurality of sliding spool directional valves and a balanced relief valve mounted in the body formed of a plurality of sections bolted and gasketed together. The main lift section has a load-holding check valve of special design together with means on the spool for opening the check valve to lower the load. Means are provided in the assembly for preventing interflow from one valve spool to another when two or more spools are simultaneously shifted. This includes a system of restrictors, check valves and passages causing the main relief valve to act as a pressure compensator responsive to the pressure requirement of the smallest load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.