Perforating apparatus with fine positioning adjustment

摘要

The device has a movable device (16) to which a holder for a perforating element (12) can be attached with a piston unit (24) for moving the movable device and a positioning device (30) for setting the starting position of the piston unit that acts directly on the piston unit. The positioning device has internal and external threads (31,29) with pitches matched so the piston movement is smaller than the rotation of the positioning unit. An independent claim is also included for the following: a method of adjusting a perforating device.