HELICAL PIPE MAKING METHOD

摘要

Apparatus for and method of helically forming pipe from an elongated strip of metal. The elongated strip is curled between the rolls of a three-roll strip curling apparatus into a curved path, with the rolls exerting lateral forces on the strip during curling for guiding the strip so that such curved path is in the form of a helical convolution in which the trailing edge of a preceding portion of the strip converges into contact with the leading edge of a following portion thereof.