Patent ID: 8136846
Filing Date: 2012-03-20
Classification: E21B,F16B,F16L,Y10T

Abstract:
1. A tubular member having a cylindrical body defined about a central longitudinal axis and having a thread form for making a threaded pipe connection capable of being screwed together and subsequently unscrewed, the tubular member comprising: a pin member having a pin end with an outer extent and having external threads cut over a given thread length with stab flanks and load flanks and crests and roots for mating with the mating internal threads of a box to make up a pipe connection, wherein the thread crests are cut on an axis which is parallel to the central longitudinal axis of the tubular member and wherein the thread roots are cut on a continuous tapered axis over the entire given thread length with respect to the central longitudinal axis of the tubular body, whereby the threads have a given thread height which is measured between the thread crests and roots, and wherein the thread height varies over the thread length in ever increasing increments in the direction of the pin end outer extent, whereby an imaginary axis drawn in line with the continous tapered axis would eventually extend to intersect the central longitudinal axis of the tubular member.