Oct. 3, 1939. L. JONES 2,175,026 FUSION WELDING Filed June 13, 1938

In N/ ent or ; Leonard Jones, bu 7. é du 4 His Attorne U. Patented Oct. 3, 1939 2,175,026

UNITED STATES PATENT OFFICE 2,175,026 FUSON WELDING Leonard Jones, Davyhulme, England, assignor to General Electric Company, a corporation of New York Application June 13, 1938, Serial No. 213,491 In Great Britain June 17, 1937 3 Claims. (C. 219-8) My invention relates to fusion welding, and My invention will be better understood from more particularly to that form of electric fusion the following description taken in connection with Welding known as atomic hydrogen Welding. the accompanying drawing and its scope will be In atomic hydrogen welding, the fusion of the pointed out in the appended claims. work parts is accomplished through the agency In the drawing, Fig. 1 is a diagrammatic illus of a "flame' of atomic hydrogen. . This “flame' tration of an atomic hydrogen welding system em * results from the recombination of atomic hydro bodying my invention; and Fig. 2 is a fragmen gen to form molecular hydrogen which occurs tary view illustrating one manner in which a limit with the release of a great amount of heat. switch forming part of the system may be em 10 Atomic hydrogen may be generated by disso ployed for securing reduced heating at the end of ciating hydrogen or a gas containing hydrogen a welding Operation. through the agency of an electric arc across which In atomic hydrogen welding, atomic hydrogen the gas is directed. By controlling the energy of is generated by an instrumentality usually re the arc by regulating its length and voltage, the ferred to as a welding head. The atomic hydro 5 amount of atomic hydrogen generated may be gen welding head illustrated in Fig. 1 may be of 5 controlled and thus the heat available for Weld the type described and claimed in United States ing may be controlled. Letters Patent 1,946,305, James T. Catlett, Feb While my invention will be described in con ruary 6, 1934. This head comprises electrodes 0 nection with a novel atomic hydrogen welding and which are fed toward and away from one system, it is to be" understood that as a method another by a feed motor 2 to maintain between of welding it is applicable to any form of fusion their arcing terminals an arc across which hydro welding. gen or a hydrogen containing gas is supplied (by When fusion welding butt or edge joints, it is a means not illustrated) to be dissociated in the the present practice to maintain the amount of arc for the formation of atomic hydrogen. Elec heat available in the welding zone as constant as trode 0 is fed by motor 2 through worm 3, . possible along the whole length of the joint so Worm wheel 4, bevelled gears 5 and 6, worm that the fusion of the metal parts at the joint f7, worm wheel 8, gear 19 and rack 20; and will be uniform along the whole length of the electrode f is fed by the same motor through joint. This is usually effected in atomic hydrogen Worm 3, Worm wheel 4, bevelled gears 5 and 30 welding by maintaining the arc voltage constant 21, worm 22, worm wheel 23, gear 24 and rack i30 assuming, of course, uniform speed of travel and - 25. Normally, bevelled gear 2 is forced into spacing of the welding electrodes along and from engagement with bevelled gear 5 by means of , the joint as well as uniform arc current and uni a spring 26 compressed between a collar on shaft form flow of gas to the arc region. 27 and the worm 22, but this driving connection It has been observed, however, that when the may be interrupted by withdrawing gear 2 from available heat in the welding region remains un mesh with gear 5 through the agency of knob 28, changed throughout the whole length of the joint, attached to shaft 27. The worm 22 is splined on there is a tendency for the molten metal of the the shaft 2 to which gear 2 and knob 28 are joint, possibly due to surface tension, to leave the attached so that this disengagement may readily 40 finishing end of the joint and flow back toward be accomplished without rotating worm 22. When 40 the middle of the joint, thus leaving a groove at gears 2 and 5 are thus disengaged, the electrode the finishing end. / - may be adjusted independently of electrode It is an object of my invention to eliminate this by turning the knob 28. However, when gears 2 groove at the end of a fusion welded joint by pro and 5 are in mesh, both electrodes O and are 45 viding a method of welding in which a substan simultaneously fed at the same rate by feed :45 tially constant amount of heat is supplied along motor 2 through the gearing just described. The the length of the joint until the weld approaches independent control of electrode through the the end of the joint when the heat is reduced agency of knob 28 thus enables the welding oper sufficiently to complete the weld without having ator to adjust the electrodes relatively to one an the molten metal at the end of the joint flow back other if for any reason they are consumed in the :50 toward the middle of the joint. welding arc at unequal rates. It is a further object of my invention to pro The armature of the electrode feed notor 2 vide a control system for electric fusion welding is connected in Series with its field 29 through the by means of which my above described method contacts of reversing contactors 30 and 3 f to a 55 may be performed automatically. source of supply 32. The operating coils of con

2. 2,175,026 tactors 38 and 38 are connected through the con point of Welding due to the reduced energy of tacts 33, 34 and 35, of a voltage relay 36 to the the arc and consequent reduction of atomic hy same source of supply 32. The operating winding drogen generated. The lower operating voltage of voltage relay 36 is connected across the elec of the arc will depend mainly upon the value of is trodes A and through an adjustable resistance resistance 38 which may be made adjustable to 3, a fixed resistance 38, and the contacts of a provide an adjustment of this lower operating relay 39. The operating coil of relay 39 is con voltage. Thus, for example, supposing the arc nected in series with an arcing circuit 40 through between electrodes 0 and i? is normally main which power is supplied for maintaining an arc tained at a voltage between 60 and 85 Volts, the between the electrodes 0 and f. closure of limit switch 42 may lower the arc The adjustable resistance 37 in circuit with the voltage to a range of 30 to 35 volts. operating winding of the voltage relay 36 is As explained above, the arrangement is Such Shunted by a limit SWitch 42. This limit Switch that the reduced arc voltage, obtained when the may be attached to the work 43 or the work sup limit switch 42 is closed, sufficiently reduces the 36 port 4 by a suitable clamp 45 so that its operat heating of the metal and its fluidity at the end ing member is in the path of travel of a project of a joint to prevent molten metal flowing back ing member A6 attached to the welding head em along the weld to any noticeable extent. It has bodying electrodes 9 and it. Any other means been found that a suitable point at which to may be employed for positioning the limit switch close the limit switch 42 is when the electrodes 2 42 so that the relative movement of the welding are positioned between a quarter and a half inch head and the Work produces a closure of this from the end of the joint being Welded. Switch near the end of the joint being welded. In Although my invention has been described in fact, if an automatic system is not desired, switch connection with a control for atomic hydrogen 42 may be located in any convenient position and welding, it is apparent that as a method of 26 closed manually by the welding operator. fusion welding it is not limited thereto. Fusion The System above described operates as foll welding is performed by electric arcs as Well aS OWS: When an arc is established between the by gas flames. In atomic hydrogen welding both electrodes ?o and by bridging their arcing an electric arc and a gas flame are instrumen terminals with a piece of carbon or by manu talities in the welding operation and, conse 36 ally feeding the electrodes toward one another quently, the performance of my method of Weld until their arcing terminals engage one another, ing by means of atomic hydrogen serves to illus the flow of current through the operating wind trate its application in both fields of fusion ing of relay 39 closes its contacts thus connect Welding. ing the operating winding of voltage relay 36 Furthermore, the system illustrated for auto 35 through resistors 37 and 38 across the arc be matically performing my method of Welding may tween electrodes 0 and . Relay 36 will thus be variously modified to meet conditions encoun be responsive to arc voltage and Will, during tered in performing various welding operations. welding, normally assume the mid or 'off' po I, therefore, aim in the appended claims to sition. If, however, the voltage of the arc be cover all modifications of my invention which tween the electrodes 0 and f exceeds a pre fall Within its true spirit and Scope. determined upper limit, voltage relay 36 will What I claim as new and desire to secure by complete a circuit through its contacts 35 and Letters Patent of the United States is: 33 to energize the operating Winding of con 1. Apparatus comprising a Welding agency in tactor 3 which will close its contacts and con cluding arc supporting electrodes, means for as nect the electrode feed motor 2 to the source traversing the arcing terminals of Said electrodes of supply 32 for rotation in the proper direc and a seam to be welded relatively to one an tion to feed the electrodes 0 and f toward one other, means for maintaining an arc between another and thus reduce the arc voltage. On the arcing terminals of said electrodes, and the other hand, if the voltage of the arc falls means responsive to the voltage of Said arc for below a predetermined lower limit, voltage relay maintaining a substantially constant predeter 36 will complete a circuit through its contacts mined spacing between the arcing terminals of 34 and 35 to energize the operating winding of said electrodes until they approach the end of contactor 39 which will close its contacts and said seam and for reducing the Spacing of the connect motor 2 to the source of supply 32 for arcing terminals of said electrodes during the 55 rotation in the opposite direction to feed the final portion of their travel along Said Seam. electrodes and away from one another and 2. Apparatus comprising a Welding agency thus increase the arc voltage. Thus, through including arc supporting electrodes, means for the operation of voltage relay 36 a substantially traversing the arcing terminals of said electrodes constant arc voltage is maintained between elec relatively to and at a substantially constant dis 60 trodes C and f. This substantially constant tance from a seam to be welded, means for main arc voltage develops a substantially constant taining an arc between the arcing terminals of 60 amount of energy which is available for gener said electrodes, means responsive to the voltage ating atomic hydrogen and the Welding Opera of said arc for maintaining according to its Set tion will, consequently, proceed with a Substan tings a plurality of predetermined spacings of 65 tially constant amount of heat supplied by the the arcing terminals of said electrodes, and atomic hydrogen to the point of welding. means responsive to the traversing movement Near the end of the welding operation, how between said electrodes and said seam for chang ever, the relative movement of the welding head ing the setting of said voltage responsive means and work will produce a closure of limit Switch and consequently the spacing of the arcing ter 70 42. The closure of this switch will short circuit minals of said electrodes at a predetermined the adjustable resistance 37 in circuit with the point in said traversing movement. operating winding of voltage relay 36 and cause 3. The method of welding seam joints by an it to function in a manner to maintain a lower atomic hydrogen process which comprises cauS arc voltage between the electrodes 0 and ing the electrodes of the atomic hydrogen Weld which in turn will result in less heating at the ing agency to travel progressively along the Sean 75 s, 178,026 3 at a substantially constant distance therefrom, travel along said sea to reduce the heating controlling the distance apart of said electrodes sufficiently along that part of the seam which so as to maintain the arc voltage substantially is welded last to prevent molten metal running constant until said electrodes reach a point ap back any substantial amount from the end of proaching the end of their path of travel along the seam toward the middle of the seam. 5 said seam, and moving said electrodes relatively near together during the remainder of their LEONARD JONES.