| 摘要 |
A powered work clamping device includes a housing having an upper chamber and a lower chamber, and a piston in the lower chamber connected to an index rod which projects into the upper chamber. The index rod is axially movable but not rotatably movable, and is biased to an upper position. A plunger extends from the housing and has a work engaging member at one end with a piston at its other end disposed within the upper chamber. The plunger is mounted on the index rod for axial and rotative movement, and is biased to a retracted clamped position. To unclamp a workpiece, hydraulic fluid is directed to a valve assembly within the device which sequentially delivers fluid first to the upper chamber to extend the plunger and then to the lower chamber to axially move the index rod and its piston to swing the plunger. To clamp a workpiece, hydraulic pressure is removed so that fluid first flows from the lower chamber through the check valve assembly to tank due to the biasing force on the index rod to swing the plunger, and then fluid in the upper chamber flows through the check valve assembly to tank due to its biasing force to retract the plunger and clamp a workpiece.
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