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:
Dec. 15, 1981
Filed:
Sep. 12, 1980
Manfred A Lupke, Thornhill, Ontario, CA;
Gerd P Lupke, Thornhill, Ontario, CA;
Other;
Abstract
The invention provides a die assembly comprising a nozzle and at least one mandrel which defines with the nozzle an annular die orifice. The nozzle has a longitudinally extending stem terminating in the sleeve, the mandrel being located coaxially within the sleeve and coupled to the stem of the nozzle by an axially extending screw threaded coupling. The mandrel includes an internal flow passage having an inlet positioned to receive thermoplastic material from a supply passage extending along the nozzle and an outlet positioned to deliver the material to an annular distribution chamber defined by the opposing surfaces of the mandrel and the sleeve. The distribution chamber provides an uninterrupted annular flow path extending from the outlet to the die orifice, thereby avoiding the disadvantage of imperfect material distribution. For the production of multiple-walled tubing, a plurality of die stages coupled together in coaxial relationships are provided, the die components being so coupled by axially extending screw threaded couplings so positioned as not to interfere with the flow of plastic materials.