CONTROL CIRCUIT FOR VARIABLE DISPLACEMENT PUMPS WITH OVERRIDE VALVE

摘要

A fluid control circuit for selectively varying the displacement of a variable displacement pump (P), such as the type employed in a hydrostatic transmission, comprises a primary control circuit connecting a pressurized fluid source (10) with the pump (P) and adapted to be actuated to selectively vary the displacement of the pump (P) between minimum and maximum values. A separate override control circuit is connected to the primary control circuit to override it to selectively vary the displacement of the pump (P).