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. 10, 1996
Filed:
Feb. 26, 1993
Nikolaus Ferenczy, Haan, DE;
Dieter Junkers, Haan, DE;
Hille & Muller, Dusseldorf, DE;
Abstract
A multi-layer metal tube consists of a flat steel band having a soldering layer connected to at least one side of the steel band. The soldering layer consists of a copper alloy having a melting point below 1020.degree.. The tube is produced by deforming the flat steel band into a tubular shape by winding or cylindrically rolling and by subsequently soldering the steel band to form the multi-layer metal tube. The soldering step prevents leaks as well as corrosion. In the corresponding method for manufacturing the multi-layer tubes the steel band in a first step is electrolytically degreased and activated in a nickel flash bath or in a copper pickling bath. Subsequently, the steel band is coated with the copper alloy which contains tin, zinc, or silver in order to reduce the melting point. After completion of the winding step or rolling step, the multi-layer tube can be coated with an additional corrosion-preventing layer.