Abstract: A quick coupling device for coaction with a check valve-equipped male device having an L-shaped passage therein with a piston-equipped spool mounted in the portion of the passage receiving the male device.

Abstract: A stroke control mechanism for a hydraulic actuator having a piston and cylinder device including a blocking valve for selectively blocking fluid flow from one side of the actuator, the blocking valve consisting of a spring biased check valve mounted on one end of a valve stem and actuable by a control bar on the piston rod at the end of the stroke of the piston, the spring biased check valve being constructed to be opened by fluid pressure flowing to the extending side of the piston without movement of the valve stem so that creepage of the piston during its retracting movement resulting in contact between the valve stem and the actuating member will not prevent reversal of the piston.