| 摘要 |
PURPOSE:To match the axis and to prevent damage of groove irrespective of eccentricity by enabling up/down motion of a pair of screw members through a hinge pin. CONSTITUTION:In order to screw the threaded members 2, 27, the eccentricity of said members 2, 27 is detected as an electrical signal to move a receiving metal 32 through cylinders 33, 35 in predetermined direction for eliminating eccentricity, thus to move an oil well tube 1 around the pin hinge section 3 and to move a tubular member 28 around the outercircumference of female screw body 48 resulting in coincidence of the axis of both members 2, 27. Upon advancing of tubular body 28 along a groove 49 by means of a motor 53, the axis of said members 2, 27 will coincide to engage them reliably because they have same pitch and phase. In other word, a tapered screw having groove of rectangular or trapezoidal cross-section will easily bite when screwing, but the biting can be prevented if the axis, pitch and phase have been matched previously. |
