Abstract: A cushioned hydraulic cylinder which includes a check valve in the cushioning path to allow fast opposite direction movement. The check valve is in the form of a cast iron piston ring located within a groove in the piston which blocks unrestricted flow across the piston when the piston ring is seated against one side face of the groove and opens unrestricted flow when the piston ring abuts the opposite side face of the groove when the piston is moving in the opposite direction.

Abstract: A load responsive system employing a fixed displacement pump and a variable displacement pump in a parallel circuit as a source of fluid in an open-center load sensing system. The load response control valve includes an unloading spool which is flow responsive in the operative positions of the control valve and maintains a constant .DELTA..rho. across the control valve by dumping the pump flow to reservoir; the control valve .DELTA..rho. being greater than the .DELTA..rho. of the pump compensator means so that the variable displacement pump will remain destroked until the system utilizes the full flow of the fixed displacement pump at which time the variable displacement pump strokes-out upon demand.

Abstract: Instrumentality for use in multiple spool control valve assemblies including a high pressure pilot operated relief valve that exhausts fluid from the chamber being protected through a pair of exhaust passages simultaneously. A pressure responsive flow restricting valve maintains a constant pressure differential on the control spools across the open center flow passages of open center valves. A low pressure regeneration circuit includes provisions for preventing excessive pressure and consequent seal blow-out in the return passages of a control valve assembly. Each of these instrumentalities is capable of being disposed in an end plate section of universal configuration for section control valve asssemblies.

Abstract: A hydrostatic parallel circuit drive system on a vehicle which drives a pair of hydraulic wheel motors which are supplied by a single pump source through a divider valve which senses the flow rate to each of the motors, and when the flow rates to the two motors vary sufficiently, the divider valve restricts the excess flow so that one wheel cannot spin and consume the entire flow to the system.

Abstract: A valve section which establishes priority flow in a valve assembly having a plurality of directional control open-center valves each for controlling flow between an associated hydraulic motor and a common power passage from a single source of motive fluid, wherein flow to one of the motors is afforded priority during simultaneous operation of it and another motor. The associated valve section of the priority motor having a conventional load check valve opened by pressure in the common power passage while the load check of the non-priority valve section is opened by pilot pressure in its open-center passage.