DRILL PIPE JOINT Russian patent published in 2003 - IPC

FIELD: hole drilling, particularly, drill pipe joints. SUBSTANCE: drill pipe joint includes pin and box with congruent location on their external and internal surfaces of nonround sections. Drill pipe joint also provided with ring located in nipple circular recess for limited rotation. Ring external surface has section similar to nonround section of nipple and its retainer relative to pin. Box has circular recess located directly under its nonround section for receiving ring nonround section. EFFECT: reduced hydraulic resistance of drill pipe flow area and provided transportation of various devices and substances through drill pipe cavity. 4 dwg