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:
Feb. 26, 1991
Filed:
Mar. 06, 1989
Applicant:
Inventors:
Gerald F Robertson, Manlius, NY (US);
Ross A Moyer, LaFayette, NY (US);
John R McManus, Marcellus, NY (US);
Assignee:
Carrier Corporation, Syracuse, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21C / ;
U.S. Cl.
CPC ...
72194 ; 72198 ;
Abstract
A method and machine for forming internal enhancement ribs in heat exchanger pipe or tubing comprises a mandrel which is supported within the tubing and a plurality of opposed rotary dies which have their axes perpendicular to the tube axis so that they rotate in the direction parallel to the tube axis. The rotary dies have a circumferential contact portion that has a concave arcuate profile. In one embodiment, the circumferential surface is scalloped with a succession of axially raised portions. In another embodiment, the rotary die carries a plurality of circumferential rollers.