Apparatus for bending corrugated pipe

Abstract

Corrugated pipe is bent by pinching the spiral corrugations on one side of the pipe to decrease their pitch and increase their amplitude as compared to the undeformed corrugations on the opposite side of the pipe, thereby shortening the pipe on one side. A machine for effecting deformation of the corrugations includes inner and outer clamp mechanisms which provide an inner spiral rib extending partially around the inside of the pipe and a pair of outer spiral ribs extending partially around the outside of the pipe. The clamps include hinged together clamp sections which are pivoted by hydraulic cylinders between a pipe engaging position for bending the pipe and a release position permitting advancement of the pipe. The cylinders drive the outer ribs toward one another as well as inwardly into grooves of the corrugations where their force is opposed by the inner rib which acts against the inside pipe surface at a ridge of the corrugation. The resultant pinching action deforms the portion of the corrugation engaged by the ribs such that its pitch is decreased and its amplitude is increased with respect to the undeformed portion of the corrugation on the opposite side of the pipe.

Dependencies are inferred from the claim text.