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:
Jul. 24, 1990
Filed:
Oct. 13, 1989
Francis J Fuchs, Jr, Naples, FL (US);
Other;
Abstract
Process of providing the internal portion of tubing with at least one spiral fin, comprising the steps of: providing a first spinner having at least two first external spiral ridges displaced a predetermined distance angularly with respect to each other and providing a first spiral groove therebetween having a first depth and providing a first spiral path; producing relative motion between the first spinner and the tubing internal portion to cause the first external spiral ridges to engage the tubing internal portion and form spiral grooves therein and to cause a portion of the tubing internal portion to flow into the first spiral groove and form a spiral fin; providing a second spinner having at least two second external spiral ridges displaced the predetermined distance angularly with respect to each other and providing a second spiral groove therebetween having a second depth greater than the first depth and providing a second spiral path; and aligning the second external spiral ridges of the second spinner with the spiral grooves formed in the tubing internal portion by the first spinner and producing relative movement between the tubing and the second spinner to cause the second external spiral ridges to compress the spiral fin and to cause the spiral fin to flow into the second spiral groove and thereby increase the height of the spiral fin.