Patent GB-594691-A (GB)
Title: Method and apparatus for flame-machining of metal bodies
IPC: B23K7/06
Filed: 1945-06-21
Abstract: 594,691. Cutting by fusion. LINDE AIR PRODUCTS CO. June 21, 1945, No. 15876. Convention date, Aug. 9, 1944. [Class 83 (iv)] In a method for flame machining or flame desurfacing elongated metal bodies, particularly cylindrical, square or rectangular billets of short length, the body is conveyed in the direction of the length to bring a surface thereof and gas stream into operative position relatively to each other and relative movement between the body and stream is effected in a direction crosswise of the body while the body is supported on a portion of a longitudinal surface transversely spaced from the part being de-surfaced. A cylindrical billet 16, Fig. 1, is drawn into the machine by a roller conveyer 15, comprising a base 17, and conical rollers 19 supported on shafts 20, rotated through gears 21., 22 by a drive shaft 23. As the billet moves into the machine, a starting groove 31 may 'be cut along its length by a nozzle 32 which is hinged to a pedestal 35 at 34 so that it may be swung away from the path of the billet. When positioned, the billet abuts an adjustable stop mechanism 24, Fig. 2, at its forward end, comprising a stop element 25 operated through links by a cylinder 26. A second'stop 27 is then brought into position at the rear end of the billet, and is adjustable on support 28 to accommodate varying lengths of work, being secured in any of a series of adjusting holes 30 by a bolt 29. Several of the, pedestals 35 may be arranged along the conveyer side, each having a combined rotating and pick-up device 36 and desurfacing heads 37 which are carried on links 52, 51, the latter having a portion 54 connected to a doubleacting fluid pressure cylinder 56 which operates to move the head down on to the billet, a stop 57 preventing the head from descending too far. Skids 58 secured to the bottom of the nozzle heads 43 ride the surface of the billet to ensure uniform penetration. The pick-up device comprises a pair of bell-cranked levers each having arms 38 positioned under the billet, and between adjacent rollers 19, and in which are journalled rollers 44, 45 driven by a chain and sprocket 59 and a shaft 61. The levers are pivoted on a shaft 39 extending longitudinally through all the pedestals and have arms 41 connected to a double-acting fluid pressure cylinder 40 which turns the levers about shaft 39 to lift the billet vertically into the path of the desurfacing jets whilst it is rotating on rollers 44, 45 ; an adjustable stop screw 42 limits this movement according to the diameter of the work. The combined length of the nozzle heads is arranged to cover the whole length of a billet, some of the jets being disconnected from the gas supply in the case of short billets, and the nozzles are so arranged as to direct a gas stream substantially tangential to the billet against the starting groove and successive surface layers as the billet rotates. Gas is supplied to the head through flexible conduits 46, 47, 48 which are connected to distributer pipes 49 supported by brackets 50 on each pedestal 35. The slag and smoke resulting from the desurfacing is removed by a shoot 65. In a modification, a bed of sufficient length to accommodate billets of varying sizes extends along one side of the machine replacing the several pedestals and a carriage having a single desurfacing head pivotally connected to a double-acting fluid cylinder as before described is mounted for longitudinal movement on the bed. The nozzles in the head are arranged to impinge tangentially on the billet surface at an angle less than 90 degrees to its longitudinal axis, so that a layer of metal is removed from the billet surface in helical form. A short starting groove only is required, or this may be dispensed with entirely eliminating the need for a cutting tool. The billet may also be desurfaced helically with a fixed nozzle carriage, the main conveyer being arranged with supporting rollers disposed in a plane at an acute angle to the axes of the billet to impart a combined rotational and translational movement to the billet. In a further modification for desurfacing metal plates, the plate 121, Fig. 5, is supported on a roller conveyer 122 having laterally spaced rolls 123 driven through bevel gears 125, 126 by a shaft 124. The rolls are supported at one end between rollers 128 and the plate overhangs at this end in the mouth of a shoot 137 provided to remove slag &c. An arm 143 carries the nozzle assembly 135 and is mounted on a platform 146, connected to a carriage 152 by parallel links 153. The carriage may be driven along tracks 155 by a reversible motor 154, between operations when resting on plates longer than the nozzle assembly, whilst a second reversible motor 147 controls the movement of arm 143 through gearing 148, pinion 150 and rack teeth 151 on the arm. As the arm moves the nozzle assembly towards the work, a fluid pressure cylinder 140 operates links 136 giving downward movement to the nozzle assembly 135 which is correctly located by rollers 145 carried on a pair of arms 144 secured to the nozzle assembly. When the desurfacing operation is completed, arm 143 is retracted and the plate may be turned over by manipulator arms 129, 130 operated by pressure cylinders 131, 132. Arm 130 is first raised to a vertical position following which arm 129 is raised and the plate 121 is transferred to arm 130 which is lowered slightly. Arm 129 is then retracted and as it falls the plate slides down on to rollers 123 with its opposite side uppermost. Both arms are then returned to their horizontal position away from the path of the nozzles. Rough vertical and horizontal adjustment of arm 143 is obtained through a pressure cylinder 156 to pivot it on links 153, 154<1> ; a stop 159 abutting link 1541 to limit the extent of travel towards the convever and a second stop 159<1> may limit rearward movement. The manipulator arms may be located at a different station, into which the plate is moved to reverse it. In a further modification, for desurfacing the opposite ends of a plate 121, Fig. 7, the arm 143 carries a bar 165 operated through links 136, 138, and two nozzle assemblies 161 and 162 are secured to shafts 172, Fig. 9, which are journalled in brackets 167 at either end of bar 165. Fluid pressure cylinders 163, 164 have levers 171 which are pinned to the upper end of these shafts causing them to rotate as the cylinders operate to move the nozzle assemblies into working position. Rollers 145 on arms 144 serve to locate and guide the nozzles as before and are in alignment with the top gas outlets in the nozzles, the lower outlets being cut off from the gas supply as required according to the plate thickness. A machine for desurfacing square billets is constructed as described with reference to figures 5 except that the manipulator comprises a pair of fluid pressure cylinders positioned beneath the roller conveyer which operate cranked levers whose free ends are brought to bear against the bottom left-hand corner of the billet tipping it to the right and rotating it a quarter turn. The manipulator levers are then retracted and two piston arms push the billet into the correct position, for desurfacing the side now uppermost, against fixed buffers on the left-hand side of the machine. The head is retracted each time the billet is turned and the conventional rollers may be replaced by skid shoes. In a still further modification for treating square billets 170<1>, Fig. 12, hook members 198 arranged between the conveyer rolls support the billet in the position 197 where skids 192 locate the nozzle assembly 191 which is operated by links 193, 195 by a cylinder 196. The hook members have shanks 202 with rack teeth 203 to engage a pinion 204 driven by shaft 205, and as these members move the billet to the right during desurfacing, they ride on rollers 211 and descend vertically down to leave the billet supported by the conveyer rolls 200. The hook on the members carries the billet to the right till it abuts a bar 181 at the position 213 where a fluid pressure cylinder 214 is operated, sending its piston 215 upwards to contact the lower right-hand side of the billet and rotate it a quarter turn to the left. Pressure cylinders 183 are then operated moving the bar 181 to the left and carrying the billet and hook members 198 back to the starting position.