Patent GB-1181645-A (GB)
Title: Welding Apparatus
IPC: B23K9/30
Filed: 1968-11-19
Abstract: 1,181,645. Welding by fusion. COMPAKO-MATIC Inc. 19 Nov., 1968 [28 Feb., 1968], No. 54793/68. Heading B3R. In a consumable wire electrode welding apparatus, an oscillating short seam or dual spot attachment comprises a casing 12 which supports a reversible motor 28 and a barrel driveshaft 24 and is provided with a spigot 18 by which it is removably secured to a welding unit housing 56 and through a bore 20 of which welding wire 59 is fed to the barrel 35. The casing 12 is secured to the housing 56 by a single screw 54 extending through the housing wall into engagement with a socket (58), or, to provide 360 degree positioning, an annular groove, in the spigot 18. A barrel holder 36 is removably secured to the shaft 24 by a spring-loaded rounded-end plunger 40 engaging one end of a transverse wire feed bore 48 in the shaft, the plunger yielding on barrel obstruction to prevent damage. Alternatively, in Figs. 3, 4 (not shown), the end of the shaft 24 is diametrically slotted and radially spread, by a tapered axial screw (25a), into yielding frictional engagement with the holder 36. A limit switch 32 used in the control circuit is actuated by a cam 34 or recess or flat of the shaft 24. A spring-loaded metal, e.g. brass, or plastics pad 8 damps backlash arising from internal gearing provided for the motor 28. A control-overriding motor reversing switch 29 may be provided. The welding wire 59 is fed to the barrel 35 by drive and idler rollers 60, 62. The motor 28 is of the permanent magnet type and is braked when the armature is shorted out. The control circuit comprises a transformer 96 feeding, respectively, through auto-transformers 101, 105 and A.C./D.C. rectifiers 102, 104, subcircuits of a wire feed motor 98 and the oscillating attachment motor 28; manual start and stop and reset buttons 83, 84; contacts 32a, 32b controlled by the actuator cam 34; a switch 94 effecting changeover from short seaming to dual spot operation; and relays some of which control time cycles. For short seaming, the switch 94 is positioned as shown. On pressing the start button 83 the wire feed motor 98 and a weld contactor relay 93 are energized, the wire 59 strikes and arcs, and attachment motor 28 is energized to move the barrel 35, the switches 32a, 32b then changing over. At the end of a time cycle the motor 98 is stopped and subsequently the relay 93 is deenergized. The motor 28 is then reversely driven to return the barrel 35 to its starting position, the switches 32a, 32b then reverting. Finally, the button 84 is pressed to re-set for the next cycle. For dual spot welding, the switch 94 is changed over. On pressing the start button 83, the wire feed motor 98 and weld contactor relay 93 are energized, and the wire strikes and arcs. At the end of a time cycle the motor 98 is stopped and subsequently the relay 93 is de-energized. The attachment motor 28 is then energized to move the barrel 35. The distance between spots is determined by a timing relay. On stopping of the motor 28, the wire feed motor 98 and relay 93 are again energized. Again at the end of the welding time cycle, the motor 98 is stopped and the relay 93 subsequently de-energized. The motor 28 is then reversely driven to return the barrel to its starting position, the switches 32a, 32b then changing over to stop the motor 28. Finally, the button 84 is pressed to re-set for the next cycle.