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.
Patent No.:
Date of Patent:
Jul. 24, 2001
Filed:
Apr. 22, 1999
Applicant:
Inventor:
Niel Edwin Nielsen, LaGrange, IL (US);
Assignee:
Viskase Corporation, Chicago, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29C 4/792 ; B29C 4/460 ;
U.S. Cl.
CPC ...
B29C 4/792 ; B29C 4/460 ;
Abstract
A method and apparatus for controlling the diameter of a clear extruded molten tube wherein the extruded tube contains a volume of a clear liquid and the level of the liquid is indicative of the tube diameter so the level rises as the tube diameter decreases. A light beam passing through the tube is refracted from a straight line path when the liquid level rises above the level of the beam. The refracting of the beam in turn triggers the introduction of air into the extruded tube to increase the diameter of the extruded, molten tube.