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. 08, 1998
Filed:
Mar. 17, 1997
Manfred A Lupke, Thornhill, Ontario, CA;
Stefan A Lupke, Thornhill, Ontario, CA;
Other;
Abstract
An extruder and mandrel assembly is used in a plastic pipe forming apparatus. The mandrel itself is formed from a pair of elongated tubes comprising an inner tube and an outer tube separated from the inner tube by a plastic flow path through the mandrel. The inner tube is formed by a pair of sleeves comprising an inner sleeve and an outer sleeve which is held within the mandrel by the inner sleeve. The inner sleeve is secured at its upstream end to the spider of the extruder head and the outer sleeve is secured by a releasable interlock to the inner sleeve with the releasable interlock being accessible from the downstream end of the mandrel. Therefore, the mandrel does not have to be released from the spider of the extruder head in order to remove the outer sleeve of the inner tube of the mandrel.