| 摘要 |
DRILL STRING COMPONENTS HAVING MULTIPLE-THREAD JOINTS Implementations of the present invention comprise drill string components having at least one thread extending around a body. The leading end of the thread can have a configuration having increased strength and resistance to jamming and cross-threading. In particular, the leading end of the thread can comprise a planar surface normal to the body. The leading end of the thread can provide an abrupt transition to full thread depth that helps reduce or eliminate cross-threading and can be oriented at an angle relative to the axis of the drill string component. The thread can further provide at least one of a variable thread width and a variable thread pitch configured to create an axial progressive fit. The thread can also provide a cylindrical thread root and a thread crest that circumscribes a frusta-cone over at least a portion of the axial length of the threads configured to create a radial progressive fit. |
