Patent ID: 6105649
Filing Date: 2000-08-22
Classification: B29C,B29K,B29L

Abstract:
Apparatus for producing a helical seam profile pipe from thermoplastic tube having a generally rectangular cross section, the apparatus comprising:a frame;a mandrel mounted on the frame for rotation on the frame about a longitudinal axis of the mandrel to helically wind the thermoplastic tube around the mandrel forming adjacent turns of the tube on the mandrel, the mandrel having a smooth, continuous external surface, an originating end, and a distal end, with a diameter of the mandrel at the originating end being generally fixed and a diameter of the mandrel at the distal end being selectively adjustable thereby to increase or decrease resistance to axial travel of the pipe formed on the mandrel for use in controlling the force by which adjacent turns are compressed together, the distal end of the mandrel having four ears formed thereon disposed at equally spaced relation to form two pairs of diametrically opposed ears;a variable length connector extending directly and continuously between each pair of opposed ears, with a turnbuckle on each connector to selectively change the length of the connector and thereby change the diameter of the mandrel at the distal end;a source of filler material;a filler material applicator located adjacent to the mandrel for continuously applying a bead of the filler material to the thermoplastic tube prior to being wound on the mandrel, each new turn of the thermoplastic pipe being brought into engagement with the preceding turn such that the applied filler material is brought into contact with a wall of the thermoplastic tube in the preceding turn for joining the new turn to the preceding turn.