Method and apparatus for forming undulating conduit

Abstract

Method and apparatus for forming conduit or pipe of various sizes into undulating, helical pipe by feeding a length of conduit at a controlled rate through a bending mechanism while also continuously rotating the pipe at a controlled rate so that bending occurs in multiple axis directions and the diameter of the helical path of the conduit centerline of the coil is less than the conduit diameter, the pitch is greater than the pipe diameter, and a straight open channel is retained through the pipe coil.

1 . A method of forming an undulating pipe comprising:
 providing a substantially straight pipe having a longitudinal axis through the center of the pipe;   providing a bending apparatus including a system for feeding the pipe through the bending apparatus;   moving the pipe in an axial direction through the bending apparatus, the bending apparatus asserting a force on the pipe to arcuately bend the pipe; and   simultaneously rotating the pipe about the longitudinal axis as the pipe is moving in the axial direction such that the pipe undulates in a generally helical path.   
     
     
         2 . The method of  claim 1  wherein the bending apparatus includes a plurality of rollers. 
     
     
         3 . The method of  claim 2  wherein the bending apparatus comprises a feed roller and a bending roller. 
     
     
         4 . The method of  claim 1  wherein the interior of the pipe includes a continuous smooth interior wall throughout a length of the pipe. 
     
     
         5 . The method of  claim 1  wherein the pipe has an interior wall that is circular in cross-section at every position along a length of the pipe. 
     
     
         6 . The method of  claim 1  wherein the pipe is moved and rotated at rates such that the pitch is substantially greater than one pipe diameter. 
     
     
         7 . The method of  claim 6  wherein the pipe is moved and rotated at rates such that the pitch is a multiple of the pipe diameter. 
     
     
         8 . The method of  claim 1  wherein the pipe is moved and rotated at rates such that the radius of the helical path is smaller than the radius of the interior of the pipe.