Abstract: In a hydraulic tool such as a crimping or cutting tool used by electric utility workers, interchangeability of heads and interchangeability of power units is afforded by connecting a cylinder on the power unit to a receiver on the head. Interlocking lugs allow the head to be secured to the power unit at any selected one of a plurality of rotational positions. A piston and a movable die in the head also have interlocking lugs. To enable the lugs on the piston and movable die to engage simultaneously with the engagement of the lugs on the cylinder and receiver, the piston is secured against rotation by a slotted guide the slots of which receive inwardly protruding pins fixed to the piston. For increased versatility, plural pressure relief valves can be selected by means of a manual selection valve to set the maximum force exerted by the tool.

Abstract: In a hydraulic tool such as a crimping or cutting tool used by electric utility workers, interchangeability of heads and interchangeability of power units is afforded by connecting a cylinder on the power unit to a receiver on the head. Interlocking lugs allow the head to be secured to the power unit at any selected one of a plurality of rotational positions. A piston and a movable die in the head also have interlocking lugs. To enable the lugs on the piston and movable die to engage simultaneously with the engagement of the lugs on the cylinder and receiver, the piston is secured against rotation by a slotted guide the slots of which receive inwardly protruding pins fixed to the piston. For increased versatility, plural pressure relief valves can be selected by means of a manual selection valve to set the maximum force exerted by the tool.

Abstract: A multi-purpose hydraulic tool of the open center and closed center type is provided with an OC/CC knob mounted on the trigger activated spool. The spool has a knob which can be turned to easily move between OC and CC operating conditions, without the use of additional tools. A check spool assembly works in conjunction with spool assembly in the open-center condition to provide for release of oil at the end of the return stroke. Adapters are provided so that crimping heads can be easily interchanged.

Abstract: A multi-purpose hydraulic tool of the open center and closed center type is provided with an OC/CC knob mounted on the trigger activated spool. The spool has a knob which can be turned to easily move between OC and CC operating conditions, without the use of additional tools. A check spool assembly works in conjunction with spool assembly in the open-center condition to provide for release of oil at the end of the return stroke. Adapters are provided so that crimping heads can be easily interchanged.