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. 26, 1976
Filed:
Aug. 11, 1975
Jerome W Nelson, Houston, TX (US);
Earl B Nay, Houston, TX (US);
Eric W Wittmann, Houston, TX (US);
Robert E Pollock, deceased, LATE OF Katy, TX (US);
by Peggy Pollock, executrix, Crow Point, IN (US);
Other;
Abstract
An annular work piece, such as a large pipe, is prepared for welding end-to-end to a similar piece, by a combination of cutting or machining and swaging or cold-rolling, to form bevel, land, and an annular fin-like projection which will better control penetration. In its apparatus aspects, an internal clamp mechanism is used to hold the pipe against rotation while also keeping it essentially circular in outline, a series of cutting tools, preferably complementing each other, is driven around the pipe and end for exterior and interior bevel surfaces with a more or less plane land surface between them. Rollers which serve to constrain and guide the cutting tools are thereafter employed to swage or cold-work the interior of the pipe end to form a small sharp-edged annular projection which serves as a heat sink to control and limit penetration of molten metal from an external electric arc into the interior of the joint. A supplementary back-up or chill may be used for further control, if needed.