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:
Sep. 28, 1982
Filed:
Aug. 13, 1979
Applicant:
Inventors:
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16L / ;
U.S. Cl.
CPC ...
138149 ; 138132 ; 138144 ;
Abstract
A tube system, which includes an inner and a concentric outer tube, is provided with a spacer made by cutting oblique notches into a polyurethane foam layer on a paper ribbon and by helically wrapping the ribbon onto the inner tube, the oblique and tapered foam elements pointing inwardly or outwardly, but the notches are aligned to form axial ducts. After forming the outer tube about the spacer, these ducts are filled with material that foams in situ.