Patent GB-594237-A (GB)
Title: Improvements in automatic positioning and welding
IPC: B23K11/00
Filed: 1945-02-28
Abstract: 594,237. Making strip. CARNEGIE-ILLINOIS STEEL CORPORATION. Feb. 28. 1945, No. 5048. Convention date, July 1, 1944. [Classes 83 (ii) and 83 (iv)] Welding.-In a positioning and welding apparatus used in the continuous process of electro-tinning &c. metal strip or the like the strip is fed by rolls driven by means which also actuate means for indicating the position of the strip, means for moving the bar for holding the strip in the desired position being controlled by the indicating means which also control means for stopping the rotation of the rolls when the strip reaches its desired position. The strip is first fed through rolls to a shearing machine, where its leading edge is trimmed, then through a welding machine and pinch rolls to a looping pit, provided for " slack " strip, which will continue to feed the remaiinder of the line whilst the first section is momentarily stopped, as the end of the first coil is brought to the welding machine and a new coil end joined to it. Two coils S and S1, Fig. 1, are supported on holders 2 and 18 ; coil S being passed through the line for processing, and whilst this is proceeding coil S1 is prepared for welding having its leading end passed through rolls 20, trimmed by a stationary blade 10 an an upper blade 22 in the shearing machine, and then suspended against a magnet 24. The entire line is now slowed down, pinch rolls 14 and the uncoilers stopped, the trailing edge of strip S trimmed by blade 10 and 8 and a push button operated to re-start the rolls and cause a wheel 74 to be brought against the periphery of the lower roll. As this wheel rotates a cable drum attached to it pulls up a weight which is set so that its position is related to that of the end of the strip moving through the machine. As the weight reaches a pre-determined height it closes a switch in a relay circuit causing a solenoid to operate a valve and admit air to cylinder 48, Fig. 3, and exhaust a cylinder 32. This causes a stop bar 40 to descend on the strip at the same time allowing weights 36 to move a pair of edge guides 26, supported on wheels 28 on tracks 30, towards the edge of the strip. As the bar and guides arrive simultaneously at their destination to clamp and position the strip, the weight, still ascending, opens a further switch stopping rolls 14, Fig. 1, and the coil holders 2. At the same time the solenoid controlling wheel 74 is de-energized, the wheel is retracted and the weight drops immediately to its starting position. Magnet 24 is now de-energized and the end of strip S1 placed in the welder over strip S to abut the surface 50, Fig. 3, of the stop bar. A further press button is operated to cause a relay to start a motor for forward travel of the welding head 64, and a clamp 52 to descend on the lapped ends of the strips. As the clamp descends it operates a solenoid to admit air to a cylinder 66, Fig. 2, and cause the head to be lowered. As the head moves towards the strip wheel 70 it makes contact completing a circuit through ground to the secondary of a transformer and closing a welding circuit to supply power to the electrodes 68. As welding is completed and wheel 70 breaks contact with the strip the parts return to normal as follows : a relay is de-energized breaking the electrode circuit, and a solenoid operates to return the stop bar and edge guides to their normal positions. The welding head is raised and its forward travel stopped ; clamp 52 is raised, and operates at the same time, a switch setting rolls 14 and the coil holder in motion and, operating the reversing motor to retract the welding head ; which is stopped by the head as it strikes a switch on reaching its normal inoperative position. The machinery of zone one now operates normally to supply strip S1 to the line and the whole speed is increased by the operator. The next coil for welding to S1 is placed on uncoiler 2, its leading edge trimmed byblades 8 and 10 and held in readiness for welding by magnet 218. Operations above are repeated for this coil &c. The welding head is provided with protective means to prevent its motor reversing during welding on forward travel.