GB1380478A - Method of and apparatus for parting workpieces - Google Patents

Abstract

1380478 Flame cutting MESSER GRIESHEIM GmbH 19 Dec 1972 [20 Dec 1971] 58505/72 Heading B3V In a method of cutting a workpiece 20 by a cutting torch 12, the torch is positioned closer to the workpiece 20 during the preheating step. The torch 12 is movable by a piston and cylinder device 28 within a guide frame 14 which is secured to a drive shaft 16 of a motor 18. In operation, the torch 12 is quickly pivoted by the motor 18 towards the workpiece 20, e.g. a continuous casting, slab or square billet, until a switch 42 on an arm 40 mounted on the drive shaft 16 is actuated by a cam 44 (position I), whereupon the motor 18 is slowed to allow the workpiece 20 to be preheated by preheating flames 17a and 17 issuing from a torch head 36 or from a separate preheating torch (38), (Fig. 2, not shown). When the switch 42 is again actuated by a second cam 44, the motor 18 is driven at the desired cutting speed and the torch 12 is raised by the piston and cylinder device 28 from its lower preheating position II determined by a stop ring 26 to a raised cutting position III. A roller (50), (Fig. 3, not shown), is mounted on the torch 12 so that any distortion of the workpiece raises the roller 50 causing the torch 12 to be moved into the protecting guide frame 14. The gap between the motor drive shaft 16 and the workpiece 20 is kept constant by a rod 48 connected to the motor 18. The pre-heating flame may be intensified by iron dust.