A punching device for shape holes in the wall of hollow bodies of an arbitrary cross-section.

摘要

Device for the punching of holes into the walls of hollow objects, particularly long lengths of tube, consisting of a framework into which the hollow material is fed sideways and pressed against one of its inner walls by springs, and a die which fits loosely into the inside of the hollow material such as to be able to move sideways and is held by a rod of still smaller area of cross section which is held in position from outside the end of the hollow object from which it protrudes.