A welding apparatus, an earth electrode for use therewith and a method for welding an object

WELDING APPARATUS, AN EARTH ELECTRODE FOR USE THEREWITH AND A METHOD FOR WELDING AN OBJECT

The present invention relates to a welding apparatus for welding an object according to the preamble of claim 1. Furthermore, the invention relates to an earth electrode according to claim 7 , and to a method according to claim 10.

There are several methods to weld metal objects. Methods suitable for use in the present invention for instance make use of an electrical circuit with a welding electrode, such as electrode welding, TIG, MIG/MAG, wherein at the location where the weld joint is to be made, metal is melted in order to interconnect the parts to be welded. A variation of this method uses a welding wire filled with gas (C0₂) (MIG/MAG welding) . This welding wire is fed from a so called welding gun. The feed speed of the welding wire can often be regulated by the user independent of the welding voltage. Another variant uses a coated melting electrode.

A common similarity between these methods is that on the one hand a welding electrode connected to a welding transformer makes contact with the object to be welded and on the other hand an earth electrode connected to the welding transformer makes contact with the object to be welded. In order to connect the earth electrode with the object to be welded a clamp is used that has to be connected manually with the object to be welded. When the welding activities predominantly take place at a restricted location such a clamp is a suitable solution for providing the earth contact. However, when the object does not have suitably formed parts for that purpose it can be both- ersome to attach the clamp.

A specific problem will occur when a welder has to perform his activities on many varying locations . In such a case the welding apparatus will have to be brought along to the next welding site and the earth electrode will have to be disconnected and reconnected fre- quently. That causes delays and loss of productivity. Moreover, due to the extra movements the user has to make for moving the welding apparatus and disconnecting and reconnecting the welding clamps, overstraining and wear of the body of the user will occur. When the welding activities have to be performed on sites that are hard to reach, it is even impossible to manually bring along the welding apparatus .

The object of the invention is to reduce at least one of the aforementioned problems .

In particular the invention aims to provide a solution for the lack of mobility of a welder.

Furthermore, the invention aims to provide a welding apparatus with which overstraining can at least be reduced.

In order to solve at least one of the aforementioned problems the invention provides a welding apparatus having the features of claim 1. Therewith the advantage is obtained that the welder can move around in a simple way, thus in fact being able to perform his activities without interruptions . The welding apparatus according to the invention moreover provides the advantage that by means of the cushion, that near the lower back is held against the back by means of the hip strap, a correct posture is provided to the user. Herewith injuries due to excessive physical effort are prevented to a large extent. Moreover it provides a firm and stable attachment of the welding apparatus on the back of the user, whereby one can work for a long period.

Within the invention the term "connected to a garment" also encompasses "worn around the garment or part thereof" for instance with a band that may or may not be elastic, a buckle or the like.

With the invention in particular an advantage is obtained when the welder has to weld objects over which he can move by walking. The welding apparatus can in fact be attached on his back in a simple and suitable way.

It is preferred that in any case the welding transformer is incorporated in a housing that is coupled to the body, which coupling is formed of one of: - a detachable coupling, and - a non-detachable coupling. In order to be able to detach the housing containing the welding transformer from the body in a simple way, it is preferred that the coupling is detachable. In this way various welding systems can be exchanged and be used by the user alternately. A highly stable coupling can be obtained when the body is coupled to the housing in a non-detachable way. '

It is preferred that the welding apparatus comprises an electrically conductive organ to be connected to the coupling for connec- tion to earth contact, to provide an electrically conductive contact with the object to be welded, wherein the organ is arranged for attachment to a garment.

According to one embodiment the organ can be an integral part of a garment, preferably selected from a jacket, vest, sweater, overalls or the like.

Additionally, it is preferred that the carrying straps are coupled to the body or the hip strap. In particular both carrying straps can be arranged for coupling to the hip belt, especially near the at- tachment position of the hip belt to the body of the welding apparatus. That will provide a further increase of the stability of the attachment of the welding apparatus on the back of the user.

In order to further increase the stability, at the height of the breast of the user a coupling strap is provided to the carrying straps for the mutual coupling of the straps. In this way the carrying straps cannot slide from the user's shoulders.

It is particularly preferred that the carrying straps comprise connecting means to attach thereto, for example to suspend therefrom, at least one of a conductor to the welding gun, an earth cable, the welding gun (the welding electrode) , additional electrodes, the earth electrode and control buttons for controlling the amperage or the speed of the wire feed. Thereby, the welding gun and the earth electrode can be easily stowed away after use of the device according to the invention while at the same time they are also directly within reach when the activities are resumed. Optionally, a holder may be provided for a mobile telephone, a walky-talky, or the like.

Another advantageous aspect of the invention resides in an earth electrode of electrically conductive material: - arranged on the one hand for the attachment thereof on the coupling for connec- tion for earth contact of the welding apparatus according to the invention, and - arranged on the other hand for the attachment thereof to a garment of a user or being an integral part of a garment of the user. For instance the earth electrode is formed as an integral part of a glove, wherein the earth electrode is connected to the palmar side or to the dorsal side thereof. The welder may then grip the object to be welded, respectively press against it with a clenched fist using the dorsal side of his glove, especially the upper side of the fingers, whereby a suitable earth contact is provided. Yet another embodiment resides in a knee protector to which the earth electrode is attached so that while kneeling on a object to be welded, electrically conductive contact is made.

A simple use is obtained when the organ is arranged for attach- ment to a garment to be worn at a limb, preferably for attachment to at least one of a glove and footwear, for instance to fingers of a glove, the palm of a glove or the sole of a shoe. Furthermore, it can integrally be part of the garment, for instance in that it is formed in the sole of a shoe or in the outer layer of a glove or knee pro- tector.

When the welder has to weld objects at low positions, the organ can suitably be formed as a knee protector. Then he can accurately perform the welding activities in a kneeled position with a usual welding gun. An alternative solution is welding while standing up- right, wherein the organ is preferably formed under the sole of a shoe or the like, and wherein the welding gun is designed with an elongated lance, whereby the welding wire leaves the welding gun at a larger distance from the handle than is the case for a usual welding gun. That embodiment is especially suitable when the welding activi- ties involve making short welding spots that do not require much accuracy, like the welding of mats of wire metal for reinforcement.

With the earth electrode according to the invention a welder can provide earth contact between the welding apparatus and the object to be welded without positioning a clamp, as a result of which the productivity is improved greatly with respect to the usual welding clamps .

A simple earth electrode is formed when the organ is an integral part of the garment, as a result of which no separate operations have to be performed in order attach the organ to the garment.

According to the invention the organ can be especially arranged advantageously for attachment to at least one of a glove and footwear, preferably to fingers of a glove, the palm of a glove or the sole of a shoe. An optional embodiment is one like a knuckleduster. By pressing the glove against the object to be welded or gripping it wearing the knuckleduster at the fingers or by standing on the object to be welded with a shoe provided with an earth electrode, electrical earth contact is obtained. If the organ is a separate organ, i.e. not provided with a garment itself, it is nevertheless preferred when parts thereof that are directed towards a body part are provided with insulating material, for increased electrical safety.

It is especially preferred that the organ comprises a means for attachment, wherein the organ is arranged for attachment to a shoe, and comprises means for fastening, preferably in the form of an electrically conductive element to be positioned under a shoe having at least one means for fastening substantially attached to opposite sides of the element and to be guided along the upper side of the shoe. For instance the organ is a plate-shaped element. The organ can for instance have approximately the shape of a shoe sole, or part thereof. Optionally, the organ has upright edges at the sides thereof, such that a shoe sole can be positioned between the upright edges and the organ cannot slide away from under the sole. The means for attachment can be formed by bands or strings that are attached to the organ and that can be guided along the top side of the shoe in order to keep the organ under the shoe.

In an analogous manner a glove may be provided with an organ at at least one of the palmar side or the backside. Preferably the device according to the invention comprises at least one of: - a glove having an integrated electrically conductive part, for instance to a palm of the hand or the fingers, and - an organ for coupling to the palm of the hand or to the fingers of a glove.

The organ can be designed as a flexible or preshaped somewhat rigid shape or can be a combination thereof.

Also a shoe may be provided with a plate integrated in the sole. Therefore the invention also relates to a garment provided with an organ for providing an earth contact between an object to be welded and a welding apparatus, preferably in the form of a shoe, a glove or a knee protector.

The electrical conductivity of the organ and the electrically conductive body must be suitable for welding applications. To that end it is preferred that a surface of the organ to be positioned against the object to be welded has a resistivity of less than 0,15 W/mm², preferably less than 0,03 /mm², more preferably less than 0, 02 W/mm².

The welding apparatus according to the invention is preferably provided with an earth electrode as mentioned previously for providing earth contact between the welding apparatus and an object to be welded. Herewith a very simple and easy to handle system is provided by means of which the activities of a welder can be facilitated greatly. Thus, the welder has a very large autonomy and can move eas- ily.

The invention furthermore relates to a method for the welding of an object using the welding apparatus according to the invention, comprising the provision of the welding apparatus and the connecting thereto of a welding electrode and an earth electrode, wherein the welding comprises the making of a circuit via the welding electrode, the object and the earth electrode. The method is characterized in that the method comprises the steps of: - the positioning of the welding apparatus on the back of a user and the attachment of the carrying straps around the shoulders, and - the attachment of the hip strap around the belly of the user. The user may connect the welding apparatus to an external source of electricity in order to carry out his activities autonomously. The method according to the invention provides the advantages mentioned hereinabove in relation to the welding apparatus according to the invention. In particular this method provides the advantage that the user will undergo less physi- cal wear, like a worn wrist and a worn back. The method provides a time saving of up to 70% for the welding of wire braiding compared to the usual manner with forceps and wire. There is no need to take along the welding apparatus separately. The method allows for a simple welding at the final building site instead of making a prefab element in a factory. Thereby errors can be prevented to a great extent .

In particular a method is preferred, comprising the steps of: - the use of an electrically conductive organ as earth electrode that is attached to a garment to be worn on a limb of a user, in such a way that it is electrically insulated from the body of the user; and - positioning the electrically conductive organ with the particular limb against the object during welding. Hereby the user can move very quickly over an object to be welded and can work highly autonomously.

Herewith it is further preferred that the electrically conduc- tive organ is an integral part of the garment since earth contact can be made therewith in a simple way.

In order to be able to use the method according to the invention in most situations, it is preferred that the electrically con- ductive organ to be attached to the garment is attached to: a shoe, a glove, or a knee protector.

A firm contact can especially be obtained when the glove with the electrically conductive organ is placed against the object with the palmar side.

The invention can for instance be very well applied when welding steel braid, like mats of wire metal for reinforcement, wherein a welder during his activities walks over the material to be welded. An organ attached to the footwear or integrated therein will then pro- vide earth contact with the material to be welded.

The present invention will now be elucidated with reference to the drawing, wherein

fig. 1 shows a schematical perspective view of a welding apparatus according to the invention,

fig. 2 shows a schematical perspective view of a welding apparatus according to the invention during the use thereof by a very experienced welder,

fig. 3 shows a schematical representation of a shoe having an integrated organ,

fig. 4 shows a schematical representation of a glove having an integrated organ,

fig. 5 shows an alternative embodiment of fig. 2,

fig. 6 shows a front view of part of the welding apparatus of fig. 5, and

fig. 7 shows a backside view of part of the welding apparatus according to the invention.

Identical or equivalent parts are designated in the figures by identical reference numerals. As a matter of fact, not all parts necessary for a proper operation of the welding apparatus are shown in the figure. However, an expert in the technique is easily capable of bringing the invention into practice based on the embodiment described here and shown in the figures .

Fig. 1 shows a schematical representation of a welding apparatus 1 having a device 2 according to the invention. The device 2 con- sists of an organ 3 provided with means for fastening 4, 4'; 5, 5' in order to attach the organ 3 under footwear (not shown in fig. 1, but shown in fig. 2) . The means for fastening can suitably be belt buckles or Velcro tape. Also a continuous elastic band may be used. The means 4, 4' are guided over the instep of the foot. The restriction means 6 make that the organ 3 cannot slide away from under the footwear .

The organ 3 serves as an earth electrode and is connected to a welding transformer by means of a conductor 9, as is usual for earth electrodes. The welding transformer can be present in a suitable manner in the housing 7 of the welding apparatus 1.

A power supply 8 is provided, as is usual for welding apparatuses. The welding apparatus 1 also comprises a welding gun 10, which is designed in a conventional manner. In the welding apparatus a feed motor (not shown) is provided for welding wire 11 that is fed through the connection cable 12 to the welding gun 10, with which the welding operation is carried out. A circuit is formed by the organ 3, the conductor 9, the welding transformer, the welding wire 11 (via the feed motor, the cable 12 and the welding gun 10) and the object to be welded (not shown) .

The welding apparatus 1 can be easily carried on a welder's back. To that end the welding apparatus 1 has carrying straps 13, 13'. This is especially shown in fig. 5, 6 and 7. According to a first embodiment as shown in fig. 1, the carrying straps 13, 13' are both coupled to an upper side and an underside of the housing 7, such that these may be positioned around the shoulders of a welder. This is shown further in fig. 2. Furthermore a chest strap 14, 14' is provided that provides for comfortable carrying. A particularly comfort- able carrying is ascertained when the welding apparatus is part of a garment, for instance a jacket. The welding apparatus may for instance be attached to a garment like a jacket, a vest, a bodywarmer or the like (not shown) .

Preferably, the welding apparatus also comprises a hip strap 22, 22' which can be attached around the belly of the user. That provides for a further improvement of the freedom of movement for the user. Notably it is preferred that the part that is to be positioned against the back of the user has an ergonomic shape. Thus the comfort will be strongly improved as a result of which the user can use the apparatus for a long time.

The housing 7 is preferably manufactured of a light material that is, however, sufficiently firm for the envisioned use, for instance plastic. The wall thickness thereof will depend on the forces that are exerted thereupon by the parts of the welding apparatus that are included in the housing.

As shown in fig. 2, a welder 15 using the device according to the present invention has a large freedom of movement. The welder only needs to bring his foot that is provided with the organ 3, firmly attached to his footwear 16 by means of means for fastening 4, 4'; 5, 5', into contact with a conductive part of the object to be welded. For instance, the welder can stand on the object to be welded (not shown) .

The organ may also be integrated in the sole of a shoe or in a glove. Such an embodiment is shown in fig. 3 and fig. 4.

Fig. 3 shows a schematical representation of a shoe 16, wherein the organ 3 is integrated in the sole 17 of the shoe 16. In the embodiment shown here the entire sole 17 is designed as organ 3. In a suitable manner an electrically conductive material is used for the shoe sole 17. In the sole 17 recesses 18 are provided to give an improved grip. Of course the sole can be provided with cam-like protrusions (not shown) which will also provide an improved grip, in which case at least the protrusions must be capable of providing an elec- trical earth contact. The sole 17 may also be fitted with grooves extending in the lateral direction of the sole (not shown) , which grooves can provide an improved grip. At the heel 19 of the shoe 16 a connection 20 is provided for coupling with the electrically conductive body (not shown) for connection of the organ 3 with the welding apparatus.

Fig. 4 shows a glove 21 that comprises organs 3 which have been applied both to the upper side of the fingers of the glove and to the lower side, here also located at the fingers. Thus, when gripping an electrically conductive part of an object to be welded an earth con- tact with the object is obtained. Also when the welder makes a fist and presses it against an electrically conductive part of the object to be welded an earth contact can be established.

By means of conductors (schematically shown with broken lines 22 ) the organs are connected to a connection means 20 that is pro- vided to couple the electrically conductive body (not shown) for connection of the organs 3 with the welding apparatus.

In particular the organs (of the garment, but particularly of the shoe or of the glove) can be made of an electrically conductive material, such as copper, iron or aluminium. Any material suitable for the envisioned use may be applied. The material is not restricted to the aforementioned metals. Other metals or electrically conductive plastics or still other materials may also be used. Preferably, the shoe or glove is designed for electric insulation of the skin with the organ. An expert is perfectly capable of designing such a shoe or glove .

Fig. 5 shows a side view of the welding apparatus 1 according to the invention. In the housing 7 the welding apparatus 1 comprises a welding transformer (not visible) having a coupling for attachment of a connection cable 12 to the welding electrode and a coupling for attachment of a conductor 9 to the earth contact. The welding apparatus also has a coupling for connection to an external source of electricity as power supply. In the embodiment shown the welding appara- tus 1 has eyes (not shown) for cooperation with hooks 27 provided on a body 24 of the welding apparatus 1. As shown in fig. 5 and fig. 7 the hooks are provided at a part 28 of the body 24. The body 24 has a longitudinal direction that extends in the direction of the spinal column of the user. A back side 32, as visible in fig. 6, of the body 24 will be directed towards the back of the user during carrying the body 24. A lumbar back support 23, here in the form of a cushion, is provided to the part 28 of the body 24. The lumbar back support 23 may be a simple thickening in the surface of the part 28 or may be a soft or hard cushion or a thickening of some sort that is formed separately on the part 28. The lumbar back support provides a support of the device against the lower back of the user.

The part 28 is attached, adjustably in the longitudinal direction, to the part 29 of the body 24. That adjustability is shown in fig. 5, 6 and 7. The parts 28, 29 are mutually coupled by means of connecting rods 30. The connecting rods 30 can be clamped against respective parts 28, 29 (clamping means not shown) , thus preventing a relative sliding of the parts 28, 29 in the longitudinal direction. In this way the body 24 can be adjusted to the length of the back of the user. The lumbar back support 23 may for instance be attached to the part 28 of the body 24 using Velcro tape, through which the lumbar back support 23 can be exchanged for another support, for instance one having a different thickness. The body 24 can then be accurately adjusted to the shape of the body of the user through which the device can provide an improved automatic correction of the posture during carrying of the welding apparatus.

At a position near the lumbar back support 23 the body 24 has two oppositely extending straps 22, 22' which can be placed around the belly of the user and can be coupled to one another. By pulling the straps 22, 22' the lumbar back support 23 can be pressed firmly against the lower back of the user. Carrying straps 13, 13' are placed around the shoulders of the user. The straps 13, 13' are with one end attached to the part 29 of the body 24 and with another end to the part 28, for instance near or at the height of the lumbar back support 23. With the other end the straps 13, 13' can also be attached to the hip strap 22, 22'.

From fig. 5 it appears that the shape of the part 29 is somewhat adapted to the shape of the upper back of the user with a convex shape. The part 28 is adapted to the lower back with a somewhat concave shape. This provides for a further improvement of the posture correcting operation of the device according to the invention.

The straps 13, 13', 22, 22' and the cushion 23 are all designed with a padding. This provides an improved comfort and the possibility to adjust the straps to the body of the user.

Fig. 7 shows a backside view of a part of the invention. The body 24 is formed of two parts 28, 29. This can also be seen in figures 5 and 6. A lower part 28 comprises the lumbar back support 23 (as shown in fig. 5 and 6). At the sides of the belly straps 22, 22' that are visible in fig. 7 Velcro tape 35 has been applied, just like to the other side of the straps 22, 22', as shown in fig. 6. In this way the straps 22, 22' can be easily coupled. On the part 28 strips 33 of reflective material have been provided for the safety of the user .

Fig. 6 shows the chest strap 14, 14' that keeps the straps 13,

13' together in order to prevent the straps 13, 13' from sliding off the shoulders. They may for instance be coupled by means of a buckle, or using another provision known in the art for the coupling of two straps, like a belt closure, a clamp, Velcro tape and the like.

The body 24 may comprise a further padding 34 for increasing the wearing comfort of the user. Like the lumbar back support 23 this padding 34 may be detachable so it can be cleaned. The padding 34 may be applied along only part of the back side 32 but also along the entire back side.

To the body 24, the carrying straps 13, 13' or the hip strap 22, 22' connecting means, may be provided to suspend conductor 9, earth cable 12, a welding gun or an earth electrode from, for instance when the user takes a break or has to perform other activities . Also a holder may be provided for separate electrodes or others tools the user may need during his activities. The suspension means may be formed of strips of material with Velcro tape.

The invention is not limited to the preferred embodiment hereinbefore described and shown in the drawing. These serve for clarification of the invention. In particular the welding apparatus 1 may be attached to the body 24 non-detachably . The body 24 may also comprise a holder instead of the hooks 27, for instance in the form of a bag or sack, for incorporating therein the housing 7 of the welding apparatus 1. A housing without eyes for receiving the hooks 27 may then also be easily incorporated in the holder to provide a welding apparatus according to the invention. All separate parts hereinbefore mentioned in the description and shown in the figures can be applied without any restriction in any desired combination. The invention is only limited by the attached claims .