Patent · US Expired

Method of manufacturing corrugated tube

US4368088A · kind A · utility

28Cited by
9References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 8, 1980
Grant dateJan 11, 1983
Priority date
Expiry dateDec 8, 2000

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29L2023/18
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A method of continuously manufacturing a corrugated tube having a corrugated outer wall and a smooth inner wall surface along the length of the tube is provided which method comprises the steps of arranging in a circular array a plurality of rollers each rotating at the same speed such that an imaginary cylinder is defined about its central axis by said rollers, the longitudinal axes of said rollers being parallel to each other but offset with respect to said central axis; continuously feeding a flat non-reinforced strip of synthetic resin material in a softened state generally perpendicularly to the length of said rollers in such a manner that said strip is helically wrapped around and advanced axially along said imaginary cylinder with portions of adjacent turns of the strip overlapping one on another and welded together; continuously feeding a flexible core member and embedding it between the overlapping portions of adjacent turns of the strip to raise the upper one of said overlapping portions so as to define spiral raised convolutions around the tube; and pressing a pressure roller against the overlappin portions of the strip having said flexible core member embedded therein; …

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