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:
Aug. 13, 1991
Filed:
Mar. 07, 1989
Applicant:
Inventor:
Erwin Siegfried, Liebefeld, CH;
Assignee:
VSL International AG, Bern, CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16L / ;
U.S. Cl.
CPC ...
138173 ; 138103 ; 138108 ; 138110 ; 138122 ; 138177 ; 745025 ;
Abstract
The wall (5) of the encasing tube (1) includes spiralling protrusions (3, 4). First protrusions (3) and second protrusions (4) run either in different directions or in the same direction but at different pitches. The encasing tube is used for enclosing tensioning cable (2) in concrete structures. By means of the particular arrangement of the protrusions, the flow properties of the grout are improved, air bubbles are virtually eliminated during injection, and the bonding properties of tensioning cables are improved by means of large bonding zones while respecting the required high fatigue strength.