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. 19, 1994
Filed:
Oct. 03, 1991
Thomas L Blose, Houston, TX (US);
David L Britten, Calgary, CA;
Kevin J Humphreys, Edmonton, CA;
Trent M Kaiser, Edmonton, CA;
IPSCO Enterprises Inc., Wilmington, DE (US);
Abstract
A pipe coupling or connection comprises a female coupling component and a mating male coupling component. Each component is matingly threaded for coupling engagement, and each is provided with an adjacent frusto-conical sealing surface. The sealing surface is provided with a controlled surface roughness, viz. very shallow fine surface variations, preferably formed as microgrooves at a pitch small relative to the pitch of the threads. The slope of the frusto-conical surface of the sealing area of the male component is slightly mismatched with that of the sealing area of the female component to simulate the bearing force vs. axial distance characteristic of shrunk-fit circular cylindrical sealing surfaces. The slight mismatch enables the sealing pressure to be above a design minimum throughout the entire sealing area yet higher at each end of the sealing area. As the coupling is assembled, thread interference in the vicinity of the sealing surface lags the occurrence of interference between the sealing surfaces. Load threads are provided with negatively inclined load flank faces. The slope of the load thread pitch line of the male element is slightly steeper than the slope of the load thread pitch line of the female element.