Patent ID: 9199294
Filing Date: 2015-12-01
Classification: B21C,B21D

Abstract:
1. Method of manufacturing a corrugated metal pipe, the corrugation having wave peaks and wave valleys, in which a corrugating device is used, said method comprising the steps of: impressing a first corrugation as a preliminary corrugation into a pipe which is moved in its longitudinal direction through the corrugating device, said first corrugation having a given axial spacing between the wave peaks; reducing the spacing between the wave peaks by subsequently obtaining a second corrugation by clamping devices resting against the pipe where two separately arranged clamping devices are both attached stationary in a radial direction, one behind the other tightly against the pipe; moving a first clamping device of said clamping devices equipped with a drive in a position of operation with the same speed as the pipe, together with the pipe; continuously pressing the pipe through the first clamping device against a fixed point defined by a second clamping device which is also provided with a drive that is arranged in relation to the corrugating unit in an axial direction behind the first clamping device to produce said reduced spacing between the wave peaks; and cyclically removing both said clamping devices from the pipe and moving each back in an opposite direction of the movement of the pipe; and resetting said clamping devices against the pipe in two new areas to be corrugate.