Patent GB-741989-A (GB)
Title: Improvements in electric arc welding
Inventor: PAYNE HAROLD SPENCER
IPC: B23K37/02
Filed: 1952-02-14
Abstract: 741,989. Electric welding. LINCOLN ELECTRIC CO. Feb. 14, 1952, No. 4014/52. Class 83 (4). In arc welding apparatus of the type in which an electrode wire is fed continuously to the work means are provided for oscillating the electrode transversely to the line of weld to increase the width of the weld. Consumable electrode wire W, Fig. 1, is continuously fed from a stationary feeding means through a flexible guide T to a carriage C moving over the work W<SP>1</SP> and having means to oscillate the wire W transversely to the line of weld. The carriage C runs on a continuous track 40 driven by a motor 31 through a sprocket 38 and is supported and guided by a handle (not shown) on the upper end of a vertical member 46. The track 40 runs over fixed and adjustable guides 42, 43 which permit the tracks to be adjusted to curved surfaces. The electrode wire W is fed to the work through a conical hopper 21 for powdered flux which is supported by a bracket 52 on the carriage, the bracket being pivoted on a bolt 51 at its upper end so that it is free to oscillate between adjustable stops 74 on each side of the carriage. The means for oscillation comprises an arm 60 engaging a hole in a flexible rubber pad supported on the bracket 52 by a casing 71 and oscillated about a pin 61, Fig. 8, on the carriage by an eccentric cam 63 driven from the motor 31 and engaging in a slot 64 in the lever 60. The amplitude of oscillation is controllable by adjusting the eccentricity of the cam 63 on the face of a gear 62 the cam being locked in position by a wing nut 67. A rubber cushioning ring 54 in the lower part of the bracket 52 supports the lower end of the hopper 21 and the upper end is supported on arms 55 projecting from the bracket 52 and support a ring 58 in which the hopper is rotatable. The ring 58 is held by wing nuts 57 and is readily detached from the arm 55 through slots 55a. The hopper 21 may, when detached, be used for manual welding without the carriage when the use of the carriage is unsuitable. In a modification the hopper 21, Fig. 9, is oscillated in a circular path, its lower end being supported in a cushioning ring 86 which is eccentrically mounted in a rotating disc 88. The disc is supported in a bracket 80 attached to the carriage and is rotated by a pinion 92. In a further example a hopper 101, Fig. 12, is stationarily supported on a bracket 102 and a pair of .electrode guides 20, 20a are oscillated inside the hopper through arms 111, 112 coupled to the guides through readily detachable links 111a, 112a, Fig. 13, passing through slots 115, 116 in the hopper wall. To permit relative movement between the guides 20, 20a and the hopper rotatable couplings 110, 110a are provided adjacent the hopper wall. The electrode oscillations may be adjusted to different amplitudes, in or out of phase with each other or alternatively one of the electrodes may remain stationary. In a further modification (not shown) the electrode wire is oscillated directly by arms engaging the wires through refractory rings, the length of wire projecting from the guides 20b, 20c being of considerable length. Control system. In all examples the welding current may be supplied from a conventional welding supply but the apparatus is particularly adapted for a method of arc welding disclosed in Specification 648,638 in which a welding current of high density is used with a weld rod of small diameter so that resistance heating of the electrode end contributes to the melting process. In a current supply and control system described with reference to Fig. 18 (not shown) the carriage driving motor 31 and a motor 3 for feeding the electrode are normally driven only during the passage of welding current and are automatically controlled by a relay through which the welding current passes, dynamic braking being provided for the electrode feed. The speeds of the carriage and electrode feed and the welder currents are manually controllable by rheostats and the electrode may be separately fed as when being inserted in the machine by push-button control. A resistor in the welder field circuit reduces the welding voltage before the arc is struck and this resistor is automatically shunted by the welding current relay. Welded joints.-A welded joint may be made on each side of butt welded sheets so that the full depth of the sheets is penetrated, the welds, Fig. 21a, being preferably staggered. With a machine in which the electrode moves in a circular path the weld metal is thrown up on one side or the other and the feature may be used to obtain a weld, Fig. 25, between a vertical and horizontal sheet. In another example in which a pair of electrodes are used and one remains stationary a weld as shown in Fig. 26 may be formed in which a deep narrow weld formed by the stationary electrode is covered by a wider weld of the oscillating electrode.