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:
Apr. 24, 1979
Filed:
Nov. 14, 1977
Jimmie B Bolton, Houston, TX (US);
Smith International, Inc., Newport Beach, CA (US);
Abstract
A tool joint is friction welded to one end of a tube. The weld area cools in air as the pipe moves to a tempering station. When the weld is below a temperature corresponding to 90% transformation from austenite to martensite, an infrared radiation responsive control viewing the weld causes an induction heating coil to be moved axially onto the end of the pipe to reheat the weld area to a temperature below austenitizing but sufficient to temper the steel, and an infrared radiation responsive control viewing the pipe radially through a radial view passage in the coil deenergizes the coil and causes it to be withdrawn. The weld is then machined off inside and outside. The weld area is next heated to austenitize the steel, following which it is fluid quenched. At a second tempering station the pipe end is moved axially into an induction heating coil to reheat the weld area. An infrared radiation responsive control viewing the weld obliquely through a slot in the coil's inner periphery deenergizes the coil at the prescribed temperature. The pipe end is then withdrawn from the coil and allowed to cool in the air.