Punch mechanism

Abstract

An apparatus for punching holes in a casing comprises an elongate casing extending between first and second ends having a plurality of punches adapted to be selectably extended therefrom, the casing having a piston cavity therein, the first end of the casing being in fluidic communication with a pressurized fluid source, a slidable piston contained within the cavity separating the cavity into extension and retraction cavities wherein the extension cavity is operable to pressurize a rear surface of the plurality of punches and the retraction cavity is operable to pressurize a front surface of the plurality of punches and a valve assembly adapted to selectably connect the pressurized fluid source with the extension or retraction cavities so as to extend or retract the punches.

Dependencies are inferred from the claim text.