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:
Oct. 02, 1990
Filed:
Sep. 08, 1989
Sumitomo Metal Industries Ltd., Osaka, JP;
Abstract
A method of manufacturing a metallic tube with a spiral fin for use as a heat transfer tube of a heat exchanger and the like. A solid metallic bar or metallic elementary hollow bar provided with a small hole is supplied to an inclined rolling mill having a plurality of rolls provided with a plurality of annular grooves formed on an outer circumferential surface thereof, and the solid metallic bar or metallic elementary hollow bar is worked into a pierced hollow bar by piercing rolling by means of a piercing plug and at the same time a fin is formed on an outer circumferential surface of the pierced hollow bar to integrate the fin with a body of the tube. Accordingly, the piercing rolling and the formation of the fin on the outer circumferential surface of the tube can be carried out at the same time, so that the manufacturing process can be remarkably shortened and the productivity can be high. In addition, a high fin can be formed and the shape of the fin becomes reliable, whereby the product can be remarkably improved in quality.