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:
May. 13, 1997
Filed:
Mar. 20, 1996
Applicant:
Inventor:
Gerhard Ziemek, Langenhagen, DE;
Assignee:
Alcatel Kabel AG & Co, , DE;
Primary Examiner:
Int. Cl.
CPC ...
B21C / ;
U.S. Cl.
CPC ...
228147 ; 2281736 ; 29890045 ; 138 38 ;
Abstract
In a method for producing internally grooved tubes for heat exchangers, a smooth metal tape is drawn from a circular supply, a rolling mill provides it with a number of grooves that are parallel to each other and run at an angle of 15.degree. to 45.degree. with respect to the lengthwise direction of the tape, the tape is continuously formed into a tube with a lengthwise slot, and the slot is welded. At least two groups of parallel grooves are rolled into the surface of the metal tape so that the grooves form a herringbone pattern.