Method and apparatus for winding a helical pipe from its inside

A machine for winding a helically wound pipe from a strip having complementary connecting formations extending along opposite edge portions thereof and which are adapted to interlock when the strip is helically wound comprising:

• a frame having at least three circumferentially spaced guide rollers adapted to bear against the inner periphery of the pipe being wound, the rollers forming a guide to enable the strip to follow a helical path along which the strip is directed when the machine is in use;
• a pair of strip drive rollers mounted to the frame structured and positioned to drive the strip around the outside of the guide rollers so as to follow the helical path and cause the adjacent edge portions of adjacent convolutions of the strip to interlock;
• and
• one or more drive units mounted to the frame for driving the strip drive roller, wherein the pair of strip drive rollers is located wholly inside the helical path and there is no support arranged to bear against the outer periphery of the pipe being wound to cause the interlock of the adjacent edge portions of the strip.

A machine for winding a helically wound pipe from a strip having complementary connecting formations extending along opposite edge portions thereof and which are adapted to interlock when the strip is helically wound comprising:

• a frame having at least three circumferentially spaced guide rollers adapted to bear against the inner periphery of the pipe being wound, the rollers forming a guide to enable the strip to follow a helical path along which the strip is directed when the machine is in use;
• a pair of strip drive rollers mounted to the frame for driving the strip around the outside of the rollers so as to follow the helical path and cause the adjacent edge portions of adjacent convolutions of the strip to interlock;
• one or more drive units located wholly inside the helical path and mounted to the frame for driving the pair of strip drive rollers;
• and
• an adjustment sub-system structured and positioned to adjust both the radial positions of the guide rollers and the angles of the axes of the guide rollers relative to the longitudinal axis of the machine.