SYSTEM FOR USE IN ELECTRODE WELDING AND GAS/ARC WELDING

Abstract: System for use in alternately electrode welding and gas/arc welding comprising a current supply cable (11) and a gas conduit in connection with a holder (10) having an associated electrode-carrying head. The holder (10) with associated current conductor member (13) is common for exchangeable first (15) and second (15') electrode-carrying heads. The first head secures the welding electrode (14) for electrode welding. The second head secures the arc electrode (14') for gas/arc welding and forms at the same time a support for a coupling member (31) for coupling to the gas conduit (32) and a control valve (33) for adjusting the supply of gas to and along the arc electrode (14').

Description: SYSTEM FOR USE IN ELECTRODE WELDING AND GAS/ARC WELDING. The present invention relates to a system for use in alternately electrode welding and gas/arc welding (TIG-welding) , comprising a current supply cable and a gas conduit in connection with a holder having an associated electrode-carrying head, an electrode being adapted to be firmly clamped with an adjustable gripping engagement between the heed and a current conductor member to which the head is firmly clamped, while a first part of the current conductor member of the holder is surrounded by the head and the holder is besides surrounded by a handle. In conventional electrode welding electric current is employed for fusing of a fusion electrode which is secured in the electrode-carrying head. Preferably the fixing of the fusion electrode or the release of the fusion electrode is effected by screwing of a handle with associated current conductor relative to the fusion electrode and the associated fastening head. When the fusion electrode is consumed, it is replaced with a new electrode by screwing the handle with current conductor relative to the electrode-carrying head. In gas/arc welding (TIG-welding) special TIG-equipment is employed which comprises a burner with associated (argon) gas conduit from a source of gas and an electrode holder having a tungsten electrode and associated current cable from a source of supply. Hitherto a combined holder for the burner and the elec- trode and a common conduit for the argon gas and the current cable have been employed. In conventional electrode welding current cables are most often employed which are extendable by means of cable joints. It is also possible to employ equivalent, but more complicated and expensive joints for the common conduit for the argon gas and the current cable in TIG-welding. Argon gas is non-combustible. Hitherto it has been usual to employ separate equipment for electrode welding and gas/arc welding respectively. In practice it has been cumbersome to employ two separate sets of euipment for conventional electrode welding and for TIG-welding. In addition heavy costs are involved in having to invest and maintain two separate sets of equipment for one and the same user at different locations of use. With the present invention the aim is a system whereby by way of simple means conventional electrode welding and gas/arc welding can be combined with a common arrangement of current supply cables, without suffering the problems which one has hitherto been burdened with. More specifically the aim is a system, where common current supply cables can be employed for conventional electrode welding and for TIG-welding. By this one can also employ arbitrarily long, especially robust current supply cables, in an equivalent manner as hitherto in conven¬ tional electrode welding. In addition the aim is to be able, by simple means, to switch from conventional electrode welding to TIG-welding by a simple exchange of components in a common holder. The system according to the invention is characterised in that the holder with associated current conductor member is common for exchangeable first and second electrode carrying heads, the first head securing the welding electrode for elec¬ trode welding and the second head securing the arc electrode for gas/arc welding and at the same time forming a support for a coupling member for coupling to the gas conduit and a control valve for adjusting the supply of gas to and along the arc electrode. According to the invention it is possible by this to employ standard equipment for conventional electrode welding, according to a normal arrangement, and immediately there is a need for TIG-welding, one can quite simply exchange the electrode welding head with a TIG-head having associated equipment, including a separate gas conduit. In this way it is sufficient for the user to bring extra to the location of use a gas container, the gas conduit and the TIG-head and otherwise utilise the robust con¬ struction for conventional electrode welding. Further features of the invention will be evident from the following description of a preferred embodiment, having regard to the accompanying drawings, in which: Fig. 1 shows partially in side elevation and partially in vertical section an electrode holder used for conventional electrode welding. Fig. 2 shows in a corresponding elevation/section the elec¬ trode holder used for TIG-welding. In Fig. 1 there is shown a known construction of an elec¬ trode holder 10 for conventional electrode welding. There is shown a current cable 11 which passes endways inwardly into a handle 12 of rubber. Internally in the handle the current cable is conductively connected to a current conductor 13. The current conductor 13 is secured with a friction-forming fastening portion 13a, in a manner not shown further, internally in the handle 12, with heat insulation between the handle and the current conduc¬ tor. The current conductor 13 projects with a stem portion 13b outwardly via a cavity in the handle 12 and a distance outside the handle and continues with a screw-threaded portion 13c towards a graduated end portion 13d. The outermost end 13e of the current conductor 13 forms a current-conducting clamp portion for engagement with a fusion or welding electrode 14. A separate fastening head 15 for securing the electrode 14 to the current conductor 13 is fixed in place on the current conductor 13 axially outside the handle 12. The head 15 comprises an external head portion 16 of hardened plastic or similar material which tolerates high temperatures and strong impacts, at the same time as it contributes electrical insulation and heat insulation. The head portion 16 is provided with an axially inner, current-conducting clamping member 17 and an axially outer fastening member 18 together with an intermediate, disc-shaped locking member 19. The fastening member 18 is locatable in a cavity 16a in the head portion 16 via a snap-forming engagement means (not shown), with which the fastening member 18, the locking member 19 and the clamping member 17 are held in place in the head portion 16. The clamping member 17 can for example be provided with longitudinal ribs which are axially displaceably guided in corresponding grooves in an inner cavity 16b in the head portion 16 and which prevent the clamping member 17 from turning relative the head portion 16. By means of the external screw thread on the current con¬ ductor 13 and a corresponding internal screw thread in the clamping member 17, the fastening head 15, that is to say the head portion 16 with clamping member 17, fastening member 18 and locking member 19, can be located, as a protective casing, in place on the current conductor 13. The locating is effected by relative rotation between the handle 12 and the fastening head 15. In the inner end of the clamping member 17 the clamping member is provided with a through, transversely extending bore 17a, which is in alignment with a one-sided, transversely extending bore 16c in the head portion 16. The outer end 13e of the current conductor 13 is adapted to be introduced laterally via the cavity 16b in the bore 17a so as to be able to be tensioned against the one side of the fusion or welding electrode 14 which is introduced via the bore 16c to the cavity 16b. The opposite side of the electrode 14 is clamped against the adjacent side of the bore 17a in a current-conducting clamping engagement. On exchanging electrode 14 the clamping engagement is loosened by a minor relative rotation between handle 12 with current conductor 13 and fastening head 15. On exchanging fastening head 15 this is effected by a more extensive relative rotation between handle with current conductor and fastening head, determined by the length of the screw thread. In Fig. 2 there is shown an electrode holder 10 having the same current cable 11, handle 12 and current conductor 13 as s shown in Fig. 1, but illustrated with an exchanged fastening head 15*. A head portion 16* is shown of corresponding construction to J the head portion 16 in Fig. 1, but with a somewhat differing shape and with diverse extra equipment. More specifically a clamping member 17' is employed which is secured in an equivalent manner to the clamping member 17 according to Fig. 1 by means of fastening member 18 and locking member 19. In the clamping member 17' there is a transversely extending, through bore 17a' in which there is located an electrode 14 ' in a manner corresponding to that which is described according to Fig. 1. The electrode 14' is a relatively thin, point ending tungsten electrode, which pro¬ jects endways outwardly to opposite sides of the current con¬ ductor 13. On the one side of the current conductor 13 the electrode 14* passes through a bore 20a in a metal bushing 20, which with a first external screw thread 21 at one end of the bushing 20 is connected to an equivalent internal screw thread in a laterally directed bore 16c' in the head portion 16'. By means of a second external screw thread 22 at the middle portion of the bushing 20 a sleeve 23 of ceramic material is fastened via an equivalent internal thread to the bushing, tightly connected to the head portion 16'. As illustrated the electrode 14 projects a substan¬ tial distance beyond the bushing 20 and a relatively short distance beyond the sleeve 23. On the opposite side of the current conductor 13 the elec¬ trode 14' passes through a dead ending bore 24a in a cap-forming sleeve 24. The sleeve 24 is fastened by means of an external screw thread 25 to an equivalent internal screw thread in the one end of a bushing 26. At the opposite end of the bushing 26 this is fastened by means of an external screw thread 27 to an equivalent internal screw thread in the bore 16c' in the head portion 16'. A transversely extending bore 28 is illustrated in the bushing 26. The bore 28 communicates on the one side with a gas passage through the bushing 26, the bore 17a 1 in the clamping member 17 and the bushing 20, the gas passage dis- charging into an open chamber 29 just within the mouth 23a of the sleeve 23. On the other side the bore 28 communicates with a duct 30 through the head portion 16' and a coupling bushing 31 fastened to this for the supply of argon gas. A gas conduit is indicated by broken lines 32. The bushing 31 and the gas conduit 32 are provided with equivalent rapid coupling parts, such as indicated at the bushing head 31a. By means of a needle valve 33, which is axially adjustable towards and away from a valve seat 33a in connection with the duct 30, the supply of gas from the gas conduit 32 to the passage along the electrode 14' can be adjusted. By a normal hand grip about the handle 12 it is rela¬ tively easy to adjust the needle valve 33 with a finger grip during use of the electrode holder. In practice the fastening head 15' can if necessary be more or less constantly coupled to the gas conduit 32, so that the fastening head 15' with associated gas conduit 32 can be trans¬ ported together with a gas container (not shown herein) to the location of use and there handle 12 and current conductor 13 of the holder are coupled immediately there is a need for TIG- welding. In other words one can readily shift thereby from conventional electrode welding to TIG-welding, and vice-versa, by quite simply exchanging the fastening heads 15 and 15' with each other.

Claims: CLAIM. System for use in alternately electrode welding and gas/arc welding (TIG-welding), comprising a current supply cable (11) and a gas conduit in connection with a holder (10) having an associ¬ ated electrode-carrying head, an electrode being adapted to be firmly clamped with an adjustable gripping engagement between the head and a current conductor member (13) to which the head is firmly clamped, while a first part of the current conductor member (13) of the holder is surrounded by the head and the holder is besides surrounded by a handle (12), characterised in that the holder (10) with associated current conductor member (13) is common for exchangeable first (15) and second (15') electrode-carrying heads, the first head (15) securing the welding electrode (14) for electrode welding and the second head (15') securing the arc electrode (14 1 ) for gas/arc welding and at the same time forming a support for a coupling member (31) for coupling to the gas conduit (32) and a control valve (33) for adjusting the supply of gas to and along the arc electrode (14').

Inventors: MYKING REIDAR, VETAAS OEYSTEIN, MYKING, REIDAR, VETAAS, OEYSTEIN
Applicants: MYKING REIDAR, MYKING, REIDAR
Application year: 1990
Main classification: B23K9
IPC codes: B23K9