Patent ID: 6513840
Filing Date: 2003-02-04
Classification: E21B,F16L

Abstract:
A drill pipe connector, comprising: a journal element that has an outer shoulder, a journal face, a tapered external thread section located between the outer shoulder and the journal face, a thread-free section located between the outer shoulder and the external thread section, and a thread-free section located between the external thread section and the journal face; and a sleeve element that can be screwed to the journal element and has an inner shoulder, a sleeve face, a tapered internal thread section located between the inner shoulder and the sleeve face, a thread-free section located between the inner shoulder and the internal thread section, and a thread-free section located between the internal thread section and the sleeve face, whereby the thread-free sections of the journal element and the sleeve element located in a region of the inner shoulder that, when a screw connection exists, lie opposite to each other, have a different length than the thread-free sections of the journal element and the sleeve element located in a region of the outer shoulder, the inner should forming a primary shoulder and the journal face tightens on the inner shoulder up to a pressure that exceeds a pressure exerted by the sleeve face on the outer shoulder when the drill pipe connector is assembled and screwed to up to 90% of its yield point so that the sleeve face tightens mainly on the outer shoulder when an additional torque occurs during boring, the thread-free sections located in the region of the inner shoulder being at least twice as long as the thread-free sections located in the region of the outer shoulder.