PURPOSE: To dispose automatically a plug for piercing on a prescribed position at the outlet side of a piercing mill without stopping a piercing line, by improving a plug bar C-hook device, in a seamless steel pipe piercing installation.
CONSTITUTION: In a plug bar C-hook device in the manufacturing installation of a hollow pipe stock for a seamless steel pipe; a moving frame 14, made freely turnable by a shifting cylinder 19, is attached onto a fixed frame 18. A shaft 9 with a fixed C-hook 8 is disposed freely movably in the vertical direction on the frame 14, and a pinion 13 which engages with a rack 12 formed in the shaft 9 is disposed on the frame 14, and the vertical moving motions of plural plug- bar C-hook devices are performed by connecting the pinions 13 by a connecting shaft. Thus the piercing plug bar is automatically carried into a prescribed position, and is arranged at the prescribed position without stopping a piercing line even when the plug bar is aged, thereby preventing the lowering of piercing efficiency.
KAWAHARA SHIGEO
TATEYAMA SHIGEHARU
ONOHARA HARUO
AZEZAKI MASAYUKI
KOBAYASHI KAZUO
OOMORI MASAKATSU
HITACHI LTD