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:
Jan. 08, 1980
Filed:
Mar. 27, 1978
Applicant:
Inventor:
Richard R Knittel, Martinsville, NJ (US);
Assignee:
Egan Machinery Company, Somerville, NJ (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29D / ;
U.S. Cl.
CPC ...
4251331 ; 425380 ; 425462 ; 425467 ;
Abstract
A coextrusion die for extruding multilayer thermoplastic material in the form of a tube. The die is of the type known as a spiral mandrel die wherein the die mandrels are provided with helical grooves on their peripheries. At least one spiral mandrel has helical grooves of opposite hand than those of the remaining mandrels.