发明名称 Threaded connector for a drill pipe.
摘要 The performances of a threaded joint for the screw connection of rod elements with frustoconical threads are at least doubled in relation to threads conforming to present standards when the opening angle ( alpha ) of the cone and the angle of inclination of the helix ( beta ) at the start of the thread are selected in such a way that their ratio is less than 2. <IMAGE>
申请公布号 EP0292464(A1) 申请公布日期 1988.11.23
申请号 EP19880870086 申请日期 1988.05.11
申请人 DIAMANT BOART SA 发明人 HALLEZ, CHARLES PIERRE
分类号 E21B17/042;F16L15/06 主分类号 E21B17/042
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