The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 02, 2000

Filed:

Mar. 19, 1998
Applicant:
Inventors:

Thomas W Hawkins, Aurora, OH (US);

Michael S Schafer, Macedonia, OH (US);

Jesse D Ellison, Sr, Garretsville, OH (US);

Assignee:

The Lamson & Sessions Co., Cleveland, OH (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29C / ;
U.S. Cl.
CPC ...
425380 ; 4251331 ; 4253823 ; 26417129 ; 2642098 ;
Abstract

An extrusion assembly includes a stationary housing section, and an outer die and mandrel for defining an annular passageway centered about an axis. The outer die and mandrel are held stationary against rotational motion about the axis. A rotor is rotationally supported on a shaft projecting into the annular passageway along the axis within the housing, for rotational motion about the axis. The rotor includes a melt channel for rotationally conveying an extrusion to the annular passageway, so as to form a helically-wound conduit that advances linearly through the annular passageway. A gear train is operative between the stationary housing, the rotor and the shaft, to hold the shaft stationary relative to the stationary housing upon rotation of the rotor.


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