Power jack for a welding device

The invention relates to a power jack (27) for a welding device (1), in particular an electrode and/or TIG welding device, wherein the power jack (27) made of conductive material comprises a bore (28) for receiving a plug element (29) attached to a hose packet, and an axial guide groove (33) is disposed in the bore (28), the guide groove being guided to the outside by way of a longitudinal groove (34) such that a locating pin (35) disposed on the plug element (29) can be inserted and rotated, wherein in the bore (28) a radial groove (36) is disposed and a retaining element (38) is positioned, preferably in the intersecting region of the groove (36) and the longitudinal groove (34), and a spring element (40) designed to transmit power is disposed in the groove (36), the spring element (40) protruding from the groove (36) and thereby reducing the diameter of the bore (28), wherein the retaining element (38) forms a contact surface (41) for the ends of the spring element (40) which is configured over only part of the entire periphery.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of PCT/AT2010/000014 filed on Jan. 18, 2010, which claims priority under 35 U.S.C. §119 of Austrian Application No. A 208/2009 filed on Feb. 6, 2009, the disclosure of which is incorporated by reference. The international application under PCT article 21(2) was not published in English.

The invention relates to a power jack for a welding device, in particular an electrode and/or TIG welding device, wherein the power jack, which is made of conductive material, includes a bore for receiving a plug element attached to a hose pack, and an axial guide groove is disposed in the bore, said guide groove being guided towards outside via a longitudinal groove such that a guide pin disposed on the plug element can be inserted and rotated.

From DE 76 41 025 U, a plug-in connection, particularly for a welding cable, is known, which is comprised of a jack part and a plug part, which are connected with each other by rotation. Furthermore, they are protected by insulating sleeves. A positive-locking connection preventing rotation is provided between the insulating sleeve and the associated jack part or plug part, respectively. The positive-locking connection is formed by a tongue and groove connection extending in the longitudinal or plug-in direction.

From DE 83 04 593 U, a unipolar electric welding-cable coupling is, moreover, known, whose plug and jack bodies are coaxially arranged and lockable by telescoping and counter-rotating by the engagement of a retaining pin of the plug body with a rising annular groove of the jack body. A supply line is conducted centrally through the plug and jack bodies. The supply line is a protective-gas or coolant line, and an annular seal abutting on the end face of the plug body is arranged in the jack body.

Those known couplings according to DE 76 41 025 and DE 83 04 593 U involve the drawback that the bayonet connection may come loose and consequently provide poor contact, whereby an increased transfer resistance will cause heating and, in the worst case, burning of the plug-in connection. This is due to the fact that welders on a construction site frequently pull on the hose pack such that the bayonet connection may come loose and cause the plug with the pin to be only loosely plugged in the opening.

From DE 43 25 289 A1, a welding cable connection is known in which a jack and contact-pin connection rotatably and safely connects the welding cable in the handle of an electric arc welding and cutting torch or on the machine side of an electric are automatic welding and cutting torch. The rotatability is ensured by the arrangement of a spring basket in the contact area of the jack. When connecting the contact pin with the jack, the contact area of the contact pin is clamped into the spring basket and secured against possible extraction by the aid of a clamping spring that engages with an annular groove provided on the contact pin. The stop arranged on the jack delimits the rotatability of the welding cable in cooperation with the guide pin arranged on the contact pin, thus protecting the control lines.

From BALSEAL Engineering, a contact system named “BalContact” is known, in which a groove with an inserted spring element is disposed in an opening of the power jack for improved contacting and power transmission. The spring element in that case has a smaller inner diameter than the opening, thus causing the spring element to project out of the groove. When a plug contact having a slightly smaller outer diameter than the inner diameter of the opening is inserted into the opening, the spirals of the spring element are being deformed. By using the spring element, several contact points are formed, providing an enhanced conductivity. The individual bending of each spiral of the spring element ensures the simple compensation of contact and surface variations on the plug contact.

This involves the drawback of only circular or round spring elements being offered, thus rendering impossible its use in not completely round openings. If the circular structure were in fact interrupted, i.e. separated, the spring element would lose its inherent stiffness and, when inserted in a groove, would fall out of the same.

The object of the invention resides in providing a power jack that ensures safe contacting even with an incorrectly plugged-in plug.

This object is achieved in that, in the bore, a radial groove is disposed and a retaining element is positioned, preferably in the intersecting region of the groove and the longitudinal groove, and that a spring element designed to transmit power, in particular a spiral spring, is disposed in the groove, said spring element protruding from the groove and thereby reducing the diameter of the bore, wherein the retaining element forms a stop surface for the ends of the spring element formed over only a part of the entire periphery.

It is advantageous that a safe seat or safe contacting of the plug element is achieved by the use of a spring element. Due to the high currents occurring during welding, it will frequently happen that the plug element will not be correctly positioned in the bore of the power jack, thus resulting in an elevated transfer resistance and overheating, and hence causing the power jack and the plug element to burn down. By using the spring element, a plurality of contact points will, however, be formed on the nose of the plug element on account of, e.g., the turns or spirals of the spring such that a very good power transfer will always be provided and no overheating will thus occur. A further advantage also resides in that, due to the use of the spring element, the bayonet connection need not be locked while a safe power transfer will nevertheless be provided. It is thus safeguarded that a safe power transfer is ensured in any position. It is, moreover, prevented that a poor contact is provided when the bayonet connection is loosened by pulling on the hose pack, which may cause overheating and, consequently, the burning-down of the plug-in connection.

Other advantageous embodiments and further developments are defined in the subclaims. Advantages resulting therefrom can be taken from the description.

FIG. 1depicts a welding apparatus1, or welding installation, for various processes or methods such as, e.g., MIG/MAG welding or TIG welding, or electrode welding methods, double-wire/tandem welding methods, plasma or soldering methods etc.

The welding apparatus1comprises a power source2including a power element3, a control device4, and a switch member5associated with the power element3and control device4, respectively. The switch member5and the control device4are connected with a control valve6arranged in a feed line7for a gas8, in particular a protective gas such as, for instance, carbon dioxide, helium or argon and the like, between a gas reservoir9and a welding torch10or torch.

In addition, a wire feeder11, which is usually employed in MIG/MAG welding, can be activated by the control device4, wherein a filler material or welding wire13is fed from a wire storage or storage drum14, such as a wire coil or wire drum, into the region of the welding torch10via a feed line12. It is, of course, possible to integrate the wire feeder11in the welding apparatus1and, in particular, its basic housing, as is known from the prior art, rather than designing the same as an accessory device as illustrated inFIG. 1.

It is also possible for the wire feeder11to supply the welding wire13, or filler metal, to the process site outside the welding torch10, to which end a non-consumable electrode is preferably arranged within the welding torch10, as is usually the case with TIG welding.

The power required for building up an electric arc15, in particular an operative electric arc, between the electrode or the the welding wired, not illustrated, and a workpiece16is supplied from the power element3of the power source2to the welding torch10, in particular electrode, via a welding line17, wherein the workpiece16to be welded, which is preferably comprised of several parts, via a further welding line18is likewise connected with the welding apparatus1and, in particular, power source2so as to enable a power circuit for a process to build up over the electric arc15, or the plasma jet formed.

For cooling the welding torch10, the welding torch10can be connected to a fluid reservoir, in particular water reservoir21, by a cooling circuit19via an interposed flow control20so as to start the cooling circuit19, in particular a fluid pump used for the fluid contained in the water reservoir21, when the welding torch10is put into operation, and hence effect cooling of the welding torch10.

The welding apparatus1further comprises an input and/or output device22, via which the most different welding parameters, operating modes or welding programs of the welding apparatus1can be set and called, respectively. In doing so, the welding parameters, operating modes or welding programs set via the input and/or output device22are transmitted to the control device4, which will subsequently activate the individual components of the welding apparatus1and/or preset the respective values required for controlling.

In the exemplary embodiment illustrated, the welding torch10is further connected with the welding apparatus1or welding installation via a hose pack23. The hose pack23houses the individual lines from the welding apparatus1to the welding torch10. The hose pack23is connected with the welding torch10via a coupling mechanism24, whereas the individual lines arranged within the hose pack23are connected with the individual contacts of the welding apparatus1via connection sockets or plug-in connections. In order to ensure the appropriate strain relief of the hose pack23, the hose pack23is connected with a housing26, in particular the basic housing of the welding apparatus1, via a strain relief means25. It is, of course, possible to use the coupling mechanism24also for connection to the welding apparatus1.

It should basically be noted that not all of the previously mentioned components need to be used or employed for the different welding methods or welding apparatus1such as, e.g., TIG devices or MIG/MAG apparatus or plasma devices. Thus, it is, for instance, possible to devise the welding torch10as an air-cooled welding torch10.

InFIG. 2, a detailed solution of the connection jacks or plug-in connections, in particular a power jack27, for connecting the line, in particular welding lines17,18, for the welding torch10is illustrated and described.

What is essential with the novel power jack27is that a safe contact is ensured in the power jack27, since very high currents are required for welding operations and a safe power transfer has thus have to be provided. In a preferred manner, the power jack27is used in an electrode and/or TIG welder.

The power jack27is preferably made of a conductive material and formed in one part. The power jack comprises a bore28for receiving a plug element29attached to a hose pack, wherein a nose30of the plug element29has a slightly smaller outer diameter31than an inner diameter32of the bore28so as to enable the insertion of the nose30into the bore28.

In the bore28is provided an axially extending guide groove33which, via a depression, i.e. a longitudinal groove34, is guided outwards so as to enable a guide pin35disposed on the plug element29, in particular on the nose30, to be inserted along the depression or longitudinal groove34and subsequently rotated into the guide groove33for fixing the plug element29. The diameter of the guide groove33preferably changes continuously such that the guide pin35will be clamped within the guide groove33by suitable rotation and a fixation of the plug element29will thus be reached.

With the power jack27for a welding device1, it is, in particular, provided that a radial groove36is arranged in the bore28. This groove36is preferably provided between the front side37of the power jack27and the guide groove33for the guide pin35, thus intersecting with the depression or longitudinal groove34. In the region of intersection of the groove36and the longitudinal groove34, a retaining element38is positioned, said retaining element38being designed in a manner comprising a depression39such that the longitudinal groove34or depression will not be interrupted. Furthermore, a spring element40, in particular a helical or spiral spring, is disposed in the groove36, said retaining element38forming a stop surface41for the ends42of the spring element40. The spring element40is designed to transmit power.

In order to provide an improved power transfer, the groove36is configured such that the spring element40projects out of the groove36. The inner diameter32of the power jack27and, in particular the bore28is thus reduced by the projecting turn parts of the spring element40. As the plug element29with the guide pin35is introduced into the power jack27, the individual turns of the spring element40are being deformed, thus providing a safe power transfer from the power jack27to the nose30of the plug element29. Due to the special configuration of the retaining element38in the region of intersection, it has become possible for the guide pin35provided on the nose30to be passed through the longitudinal groove34and the retaining element38, and subsequently be fixed in the guide groove33by rotating the guide pin35.

As is apparent fromFIG. 3, it is further possible to provide a power jack27configuration in which the retaining element38described inFIG. 2and inserted or installed is no longer used. In this case, the groove36for the spring element40is not provided over the entire periphery, but a web43is formed between the longitudinal groove34and the groove36, so that the spring element40is supported on the web43and a safe retention of the spring element40in the bore28of the power jack27will thus again be ensured.

A safe retention of the spring element40in the bore28of the power jack27is also achieved in the further exemplary embodiment according toFIG. 4. In this case, the power jack27comprises two bores44extending in the groove36for the spring element40. By inserting stop elements45into the bores44, it will be achieved that a stop surface41for the spring element40will again be provided in the groove36for the spring elements40so as to enable the retention of the spring element40in the groove36. In this case, it is also possible to provide the bore44with a thread such that the stop element45can be simply screwed into the bore44from outside.

In the embodiment according toFIG. 5, a safe retention of the spring element40is again achieved, to which end pin bores46departing from the end face37of the power jack27are provided in parallel with the longitudinal groove34on each side, into which a pin47can then each be respectively inserted. These pin bores46, and the pins47, intersect with the groove36for the spring element40so as to form a stop surface41for the spring element40by inserting the pins47.