MULTIPLE DRILLING MACHINE FOR DRILLING OR CLEARING HOLES IN HOLLOW CYLINDER

摘要

A gang drill head having a row of drills spaced according to repeated patterns of holes in a tubular member such as a suction roll in a paper-making machine which are clogged and are to be cleared by drilling the same, the drill head being guided for longitudinal movement along a guide member positioned upon the roll for circumferential incremental movement to effect radial movements of the rotating drills for the full circumference of the roll and the head including longitudinal adjustment of individual drill supports in accordance with the spacings of the repeated patterns of holes in the roll. The individual drill chucks are rotated simultaneously and manually controlled linkage causes raising and lowering of the drill head by a fluid-operated unit.