Patent · US Expired

Extrusion screw for thermoplastic matter

US5020915A · kind A · utility

14Cited by
9References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 11, 1989
Grant dateJun 4, 1991
Priority date
Expiry dateMay 11, 2009

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/12
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

The extrusion screw for thermoplastic material comprises a helical thread, having a trapezoidal profile with a flat crest and inclined flanks, the pitch and the width or the root of which remains constant, while the inside diameter of the screw increases from the entry of the screw in the direction of the exit.

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