Wrapping of pipes or tubes
AssigneeMannesmann Aktiengesellschaft
InventorsHelmut Landgraf, Walter Quitmann
Life of this patent
Estimating the term…
Abstract
A steel pipe with longitudinal welding seam is wrapped helically by means of a polyethylene ribbon which is normally stretched, but temporary stretch relief provides for a thicker envelope above and adjacent to the seam. A ribbon deflector roll and a pressure roll provide the stretching through a speed differential which is changed as stretch relief.
Claims11
In a method of wrapping thermoplastic ribbon, tape or strip around a pipe or tube, which has a welding seam and rotates on its axis and advances axially so that the ribbon, tape or strip is wound helically onto the pipe or tube and wherein the speed of payout of the ribbon, tape or strip is slower than the tangential speed of the surface of the rotating tube or pipe thereby stretching the ribbon, tape or strip just ahead of winding, the improvement of temporarily relieving the stretching for a period which is short relative to the period of one revolution of the pipe for locally increasing the thickness of the ribbon, tape or strip as wound on the tube or pipe for covering an axial portion of the seam with a thickened tape;
- and periodically repeating the temporary relief at the rate of rotation of the pipe or tube to obtain an axially extending region of thicker thickness of an envelope as resulting from said winding.
Method as in claim 6, including changing the speed differential to obtain said relief.
Dependencies are inferred from the claim text.