CUTTING OPENINGS IN PIPES.

摘要

An improved pipe having an incised aperture wherein the length and/or width of the aperture increases from the interior surface of the pipe to the exterior thereof; a process and apparatus for cutting an aperture in the surface of a pipe in which means for revolving a cutter about the pipe to be cut are provided and means for moving the cutting surface in an epitrochoid path as it passes through the exterior surface of said pipe.