Patent · US Expired

Method for producing a helically shaped, seamless multi-walled cylindrical article

US7550102B2 · kind B2 · utility

2Cited by
11References
17Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 1, 2002
Grant dateJun 23, 2009
Priority date
Expiry dateSep 4, 2023

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29L2031/60
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A method of making a composite tubular article made up of at least two concentric members, the outer of said members being tubular and the inner of said members being at least cylindrical and preferably tubular, and struts disposed in supporting and positioning orientation between the inner and outer members, by extruding a moldable material into the desired profile; stretching the inner tubular member over a cooling mandrel and disposing a cooling sleeve over the outer tubular member under conditions sufficient to solidify the article; twisting and longitudinally pulling the solidified article, so that it rotates over the cooling mandrel and inside the cooling sleeve while it is moving down stream across the cooling mandrel, whereby causing the extrudate to be twisted into a helical shape.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.