GB1333956A - Mandrel assembly and a method of ejecting a plug from a mandrel - Google Patents

Abstract

1333956 Rolling tubes NIPPON KOKAN KK 19 April 1971 10006/71 Heading B3M A tube rolling mill comprises a mandrel 3 with a plug 7 at its free end and a pneumatic actuator 5 to eject the plug after the rolling on to a recovery apparatus 6 which raises the plug into alignment with the mandrel. The plug is held in the mandrel 3 by a plug pin 70 slidably fitted in the bore 32a of a mandrel cap 32. The pin is aligned with a push rod 30 welded to the end of a cooling tube 12 axially slidable inside the mandrel. The tube 12 has water outlets (16), Fig. 3 (not shown), and the water is supplied via inlets (44) from a casing (42), Fig. 5 (not shown), in which the tube slides. The tube 12 is connected to an actuator rod 41, Fig. 1, of a pneumatic actuator 5. The actuator is a doubleacting piston-cylinder unit, Fig. 6 (not shown), and during rolling the piston is urged continuously towards the plug by air pressure from an accumulator 58. Thus, during rolling the plug is being urged away from the mandrel against the rolling force and as soon as the tube has passed over the plug the plug is automatically ejected. The ejected plug is received on a shoot 63 and directed to a tray 80, Fig. 8. The tray is pivotally mounted on an inclined slide 64 moved by an actuator 67. The tray 80 has contacts 78 which abut against contacts 85 to tilt the tray and the tray deposits the plug on to a table 84. The table is in line with the mandrel so that after the plug has been air or water cooled it can be reloaded.