Slide valve for hydraulic control distributor - has primary valve slide controlled by limiting spring and containing second pressure limiting slide valve

摘要

The hydraulic distributor has a slide valve connected to a control unit which can move the slide valve into either the control or distribution positions. At least one fluid distribution or control circuit is applied or cut off via an annular reaction chamber. The fluid can be returned into a supply or collecting tank. A primary, main slide valve is provided, which is subjected to the effect of a controlled limiting spring and is fitted a second slide valve. The two slide valves form between them a ring-shaped chamber with reactive cross-section, this chamber being capable of causing the primary slide valve to interrupt fluid flow. Should a short period of excess pressure occur, caused by heavy operation of the control unit, the primary valve is brought to a stop position.