TANDEM JOINT OF POLISHED ROD WITH SUCKER ROD STRING Russian patent published in 2001 - IPC

FIELD: operation of oil wells with sucker-rod pumps. SUBSTANCE: gripping member is split and has riffled internal surface for sucker rod. Gripping member is made in the form of tandem of upper and lower parts, each conjugated from outside with removable bushing fixed in body. Upper part and free end of sucker rod are connected with each other by joint excluding their axial displacement relative to each other. Internal cavity of body is isolated from effect of environment. In its upper part, body has thread for joining with polished rod. Tandem joint of polished rod with sucker rod string guarantees reliable coupling with body of sucker rod due to its lock joint with upper gripping member and uniform distribution of load between tandem gripping members. EFFECT: improved design. 1 dwg