Electrical contact device and electrical welded connection and method for producing a contact device and for establishing a welded connection The invention relates to an electrical contact device, in particular a compacted section of an electrical connector, preferably an electrical cable, for use in the medium-current or high-current range, and to a method for producing such an electrically conductive connection partner, for example for supplying and/or distributing electrical energy. In addition, the invention relates to an electrical welded connection for use in the medium-current or high-current range, and to a method for establishing such an electrically conductive welded connection, for example for supplying and/or distributing electrical energy.

In the electrical sector (electrics, electrical engineering, electrical power engineering etc.), a large number of electrical connectors or connection partners are known which serve the purpose of transmitting electric currents and voltages in the medium-current or high-current and/or medium-voltage or high-voltage range. In this case, the connectors need to ensure, permanently or temporarily, problem-free transmission of electric power, for example for supplying and/or distributing electrical energy in warm, possibly hot, uncontaminated, humid and/or chemically aggressive environments. Owing to a wide range of applications, a large number of connectors are known in the automotive sector or in a non- automotive sector.

Such connectors, for example an electrical cable or a cable harness, or the electrical contact devices thereof can be installed on an electrical device, such as, for example, on a busbar, in a battery or a rechargeable battery, in an inverter, in a switchgear assembly, etc. High fuel costs and attempts to reduce environmental impacts make electric and hybrid vehicles necessary in the automotive sector, for example. One aspect of these vehicles is handling of high electric operating currents and/or voltages, wherein the relevant components of the vehicles need to be designed accordingly. This relates to high-current/high- voltage cables, including the contact devices thereof, for example. Laser welding of a contact device to a mating contact device is subject to a certain limit in the prior art, which relates to the relevant cross sections to be welded of the two contact devices. An aim here is a ratio of 1 :1.5, for example for laser welding a compacted section of a copper braided wire to a connection device, for example for a module of a battery or a rechargeable battery. That is to say that the mating contact device (connection device) should be approximately 50% thicker than the contact device (compacted section) in order to effectively exclude the possibility of shoot-through. It is thus not possible in the prior art, for example, to weld a contact device to an already fitted mating contact device which is slightly thinner, the same thickness or even thicker than the mating contact device.

An object of the invention consists in specifying an improved electrical contact device and an improved electrical welded connection. In addition, an object of the invention consists in specifying an improved method for producing an electrically conductive connection partner and an improved method for establishing an electrically conductive welded connection. It should be possible in accordance with the invention to weld comparatively large cross sections of a contact device of an electrical connector to a mating contact device of a mating connector, in particular by means of a laser. In this case, it should be possible, inter alia, to weld a comparatively large, i.e. larger, cross section of the contact device to a comparatively small, i.e. smaller, cross section of the mating contact device via the contact device.

The object of the invention is achieved by means of an electrical contact device according to Claim 1 ; by means of an electrical welded connection according to Claim 2; by a method for producing an electrically conductive connection partner according to Claim 6; and by a method for establishing an electrically conductive welded connection according to Claim 7. Advantageous developments, additional features and/or advantages of the invention result from the dependent claims and the description below.

The electrical contact device according to the invention, in particular a compacted section of an electrical connector, preferably of an electrical cable, for use in the medium-current or high-current range has, in a first approach, a comparatively large cross section with a comparatively large cross-sectional dimension for a throughflow of an electric current. In accordance with the invention, the contact device has a forming region, in particular a re-forming region, having a comparatively small cross-sectional dimension, via which forming region the contact device is weldable and/or is welded to an electrical mating connector. That is to say that the welded connection is producible or is produced with the mating connector over the forming region or the re-forming region of the contact device, which region has a comparatively small cross section or the

comparatively small cross-sectional dimension. The electrical welded connection according to the invention for use in the medium-current or high-current range for the automotive sector or a non- automotive sector has an electrical connector, which is welded to an electrical mating connector and whose electrical contact device has, in a first approach, a comparatively large cross section with a comparatively large cross-sectional dimension for a throughflow of an electric current. In accordance with the invention, the welded connection is introduced between a forming region, in particular a re-forming region, the contact device having a comparatively small cross-sectional dimension, and the mating connector. That is to say that the contact device has the forming region or the re-forming region having a comparatively small cross section or the comparatively small cross-sectional dimension, over which the contact device is welded to the mating connector.

In embodiments of the invention, the connector has, within its contact device which is to be welded or is welded to a mating contact device of the mating connector, the forming region, wherein the welded connection can be introduced or is introduced between the forming region and the mating contact device. In accordance with the invention, the forming region is in the form of a re-forming region of the contact device, wherein the re-forming region is preferably in the form of a welding and stamping or welding and cavity-forming region. In addition, the re-forming region can be referred to as a re-forming and welding region. That is to say that the re-forming region can be established, for example, by means of a pressure re-forming method such as, for example, an indentation forming method. Such a method is, for example, a method for impressing or cavity- forming (cold or warm). This can be performed, for example, during compacting to form the contact device.

In accordance with the invention, the connector can be in the form of an electrical cable, in particular a braided wire, a braided cable, a litz wire cable or a module connector. In this case, the contact device can be a section to be compacted or a compacted section of the connector. In accordance with the invention, the welded connection can be or is introducible and/or introduced exclusively between the forming region and the mating contact device. Preferably, the comparatively small cross-sectional dimension is a cross-sectional height of the cross section. The contact device can be formed in accordance with a method according to the invention for producing an electrically conductive connection partner. In addition, the welded connection can be introduced in accordance with a method according to the invention for establishing an electrically conductive welded connection.

A preferred ratio of the remaining cross-sectional height in the forming region to a cross-sectional height of the mating contact device is approximately 1 :1 .2 to approximately 1 :1 .8 (Qabi ₀ o: Qab ₃ o, see below), in particular approximately 1 :1.35 to approximately 1 : 1.65 and preferably approximately 1 : 1 .45 to approximately 1 : 1 .55. This can be applied analogously to the cross sections or cross-sectional areas as well. The remaining cross-sectional height of the contact device in the forming region is approximately 0.6 mm to approximately 2.0 mm, in particular approximately 0.75 mm to approximately 1.7 mm, and preferably approximately 0.85 to approximately 1.5 mm, and in particular preferably approximately 0.95 mm to approximately 1 .25 mm. In accordance with the invention, the

comparatively small cross section of the contact device can be referred to as a welding cross section or the comparatively small cross-sectional dimension of the contact device can be referred to as a welding cross-sectional dimension.

In the method according to the invention for producing an electrically conductive connection partner, in particular an electrical cable for supplying and/or distributing electrical energy in the medium-current or high-current range, the connection partner has a contact device, which can be welded to a mating contact device of an electrically conductive mating connection partner. In accordance with the invention, a forming and welding region, in particular a reforming and welding region, is introduced into the contact device through a surface of the contact device for welding to the mating contact device. That is to say that an original section or original sections of the surface of the contact device is or are substantially maintained. The welded connection can then be established between the forming region or the re-forming region and the mating contact device. In the method according to the invention for establishing an electrically conductive welded connection for supplying and/or distributing electrical energy in the medium-current or high-current range, an electrically conductive connection partner is mechanically and electrically connected by the welded connection to an electrically conductive mating connection partner. In accordance with the invention, the connection partner has, within its contact device which is to be electrically connected to a mating contact device of the mating connection partner, a forming region, in particular a re-forming region, wherein the welded connection is established over the forming region and the mating contact device. The forming region or the re-forming region is in this case preferably introduced into the contact device through a surface of the contact device.

Temporally after the production of the connection partner and/or temporally during the establishment of the welded connection, a laser beam or a welding tool can be directed or premoved onto a base of the forming region of the contact device, wherein the welded connection is established over the forming region between the contact device and the mating contact device. In accordance with the invention, the contact device can have, in a first approach, a comparatively large cross section or a comparatively large cross-sectional dimension for a throughflow of an electric current. The forming region of the contact device can have a comparatively small cross section or a comparatively small cross- sectional dimension, over which the contact device is welded to the mating connector.

In embodiments of the invention, the connection partner is an electrical cable, wherein the contact device of the cable is in the form of a compacted section of the cable. Temporally during compacting of the section of the cable in question or temporally after the compacting of the section of the cable in question, the forming region can be introduced as a re-forming region into the section to be compacted or the already compacted section of the cable. In accordance with the invention, the connection partner to be produced can be in the form of an electrical contact device according to the invention. In addition, in this case the welded connection to be established can be in the form of an electrical welded connection according to the invention.

In accordance with the invention, it is possible to weld comparatively large cross sections of the contact device of the connector to the mating contact device of the mating connector, in particular by means of a laser. Other welding methods can of course be used. In this case, it is possible to weld a comparatively large cross section of the contact device to a comparatively small cross section or a comparatively small cross-sectional dimension of the mating contact device via the contact device. For example, it is possible in accordance with the invention, whilst maintaining the dimensions, in particular the cross section, of the mating contact device, to increase a weldable cross section of the contact device from approximately 25 mm ² to at least 35 mm ² to 50 mm ² .

The invention is explained in more detail below using exemplary embodiments with reference to the attached schematic drawing, which is not true to scale. Elements or component parts which have an identical, univocal or similar design and/or function are characterized by the same reference symbols in the description, the list of reference symbols and/or in the figures (Fig.) of the drawing. Possible alternatives, steady-state and/or kinematic reversals, combinations, etc., which are not explained in the description, are not illustrated in the drawing and/or are not exclusive, with respect to the embodiments of the invention explained and/or illustrated or individual assemblies, parts or sections thereof are set forth in the list of reference symbols.

All of the features explained, including those in the list of reference symbols, can be used not only in the specified combination or combinations but also in another combination or other combinations or on their own without departing from the scope of the invention. In the figures in the drawing:

Fig. 1 shows a laterally broken-away perspective view of an embodiment of an electrical contact device according to the invention and an electrical welded connection according to the invention;

Fig. 2 shows a centrally sectioned illustration of a second embodiment of a contact device according to the invention and a welded connection according to the invention;

Fig. 3 shows, in a similar view to that in Fig. 1 , the contact device

according to the invention and the welded connection according to the invention shown in Fig. 1 used for a braided wire;

Fig. 4 shows a perspective view of an application of the invention for an electrical connector in the form of a braided wire comprising an electrical connector device; and

Fig. 5 in turn shows a perspective view illustrating the application of the invention for an electrical module connector in the form of a braided wire for batteries or rechargeable batteries.

The invention is illustrated in more detail below with reference to embodiments of a variant of an electrical or electromechanical connector 1 or connection partner 1 . The connector 1 is in this case in particular explained in more detail as an electrical cable 1 in the form of a braided wire 1 , which electrical cable is in the form of a module connector 1 , for example (cf. Fig. 5). In this case, the invention is not restricted to such a variant and/or these embodiments, but is more basic in nature, with the result that it can be used for all electrical connectors, in particular for an application in the electrical medium-current or high-current and/or medium- voltage or high-voltage range, for example for supplying and/or distributing electrical energy. These are, for example, cable harnesses, braided cables, litz wire cables, connections, connection devices, connection apparatuses, etc.

The connector 1 has, if appropriate, an electrically conductive contact device 10 which is formed or configured in accordance with the invention and which can be connected, if appropriate in accordance with the invention, to an electrically conductive mating contact device 30 of an electrical or electrochemical mating connector 3 or mating connection partner 3 by means of, if appropriate, a connection 2 which is integral in terms of materials in accordance with the invention, in particular an electrically conductive welded connection 2. In the exemplary embodiments, the contact device 10 is in the form of a section to be compacted or compacted section of the cable 1 . It is of course possible for the invention also to be applied to other contact devices 10, which are formed so as to be crystalline, homogeneous and/or amorphous, for example. The mating contact device 30 is in this case in the form of a contact 30 of a connection 3. The connector 1 can in this case (cf. Fig. 5) be part of an electrical device 0, an electrical apparatus 0, an electrical module 0, an electrical appliance 0, electrical equipment 0, an installation 0, a system 0, etc. for the automotive sector or a non-automotive sector. The connector 1 according to the invention is suitable, for example, for a busbar 0, such as a conductor bar 0, a distribution board 0, a busbar distribution system 0, etc.; a battery 0 or a rechargeable battery 0, such as a traction battery/rechargeable battery 0, a drive battery/rechargeable battery 0, a cycle battery/rechargeable battery 0 or a module 0 thereof (cf. Fig. 5, which shows the module connector 1 ), etc.; an inverter 0; a switchgear assembly 0 etc. In general, the connector 1 is suitable for the medium-current or high-current and/or medium-voltage or high-voltage range. The contact device 10 is, in a first approach, mirror-symmetrical, in particular substantially in the form of a square, which has, in a longitudinal direction L of the contact device 10, a substantially constant rectangular, comparatively large cross section Q ₁₀ or a substantially constant, comparatively large cross-sectional area Qio (cf. Fig. 2). However, the contact device 10, as a deviation from its form specified in the first approach, has at least one groove 100, one depression 100, one constriction 100, one recess 100, one cutout 100 etc., which is introduced into the contact device 10 by means of a forming method, in particular a reforming method (second approach). That is to say that the contact device 10 has, in addition to its regular formation, a forming region 100 or a re-forming region 100, in regions or sections.

In this case, for example, a braided wire 1 comprises, on at least one longitudinal end section, the contact device 10 (cf. Figs 3 and 4). In addition, contact devices 10 (cf. Fig. 5) can also be formed on both longitudinal end sections, for example of a braided module connector 1 for rechargeable batteries. A contact device 10 of the braided wire 1 or of the module connector 1 has, in accordance with the invention, an impressed portion 100 introduced by means of re-forming, which impressed portion in this case has the form of a substantially circular, closed groove 100. In this case, the groove 100 is introduced into the relevant contact device 10 coming from a comparatively large side of the braided wire 1 or the module connector 1 .

The comparatively large cross section Q ₁₀ or the comparatively large cross- sectional area Qi ₀ of the contact device 10 in the first approach is a cross section Q or a cross-sectional area Q without in the process taking into consideration a cross section Q ₁₀ o or a cross-sectional area Qioo of the forming/re-forming region 100. Thus, a profile of the cross section Q of the contact device 10 in the first approach always has a substantially constant cross section Q ₁₀ or a constant cross-sectional area Qi ₀ in the longitudinal direction L (cf., in Fig. 2, a dashed surface 1 1 of the contact device 10). In addition, the cross section Q ₁₀ or the cross-sectional area Qi ₀ denotes a cross section Q or a cross-sectional area Q of the contact device 10 outside the forming/re-forming region 100, which also applies to a second approach, in contrast to further above in this paragraph.

In the second approach, i.e. when taking into consideration the forming/reforming region 100 or the forming/re-forming regions 100, a changing profile of the cross section Q or the cross-sectional area Q with respect to the longitudinal direction L is produced. The cross section Q or the cross-sectional area Q of the contact device 10 changes from the cross section Q ₁₀ or the cross-sectional area Qio in sections where there is no forming/re-forming region 100 to the

comparatively small cross section Q ₁₀ o or the comparatively small cross-sectional area Qioo in sections where a/the forming/re-forming region 100 is provided. That is to say that the cross section Q ₁₀ o or the cross-sectional area Qioo is the cross section Q of the contact device 10 in the forming/re-forming region 100 or of the forming/re-forming region 100. In this case, the cross section Q ₁₀ o itself or the cross-sectional area Qioo itself in the forming/re-forming region 100 can again change in the longitudinal direction L along the contact device 10 (cf. Fig. 1 and Figs 3 to 5). The cross section Q ₁₀ or the cross-sectional area Qi ₀ of the contact device 10 always only takes into consideration the first approach, in which the cross section Q ₁₀ o or the cross- sectional area Qioo of the re-forming region 100 is not taken into consideration, irrespective of whether the cross section Q ₁₀ or the cross-sectional area Qi ₀ of the contact device 10 is now reduced by means of a re-forming region 100 or not. The forming/re-forming region 100 can also be referred to as forming/re-forming and welding region 100, stamping/cavity-forming region 100, welding and stamping/cavity-forming 100 and/or the cross section Q ₁₀ o can be referred to as welding cross section Q ₁₀ o-

In accordance with the invention, the forming/re-forming region 100 is provided in the contact device 10 through a surface 1 1 , wherein a base of the forming/re- forming region 100 is within the contact device 10 and is accessible through an opening in the forming/re-forming region 100, for example for a laser beam or a welding tool of a welding apparatus. During welding, a region beneath and to the side of the forming/re-forming region 100 fuses with the mating contact device 30 (welded connection 2), wherein the contact device 10 and the mating contact device 30 are fixedly held together so as to form a throughflow region 20 or a throughflow area 20 for the electric current between the contact device 10 and the mating contact device 30. A flow of the electric current through the throughflow region 20 is illustrated by the double arrows D in Fig. 2.

In accordance with the invention, the contact device 10 is only welded to the mating contact device 30 in the forming/re-forming region 100. As a result, it is no longer possible for welding to be performed at any desired points on the contact device 10. Tests have shown that, by welding only in the forming/re-forming region 100, no disadvantages occur with respect to the prior art, in which welding is performed through the surface 1 1 of the contact device 10. An electrical resistance is not influenced, and the mechanical cohesion owing to the welded connection 2 is still so high that the connector 1 (when using a braided wire 1 ) rips and does not interrupt the welded connection 2. In addition, the welded connection 2 according to the invention likewise has no disadvantages thermally.

A form of the forming/re-forming region 100 is in principle as desired. Thus, for example, a form which is closed per se such as a circular ring 100 (cf. Figs 1 and 3 to 5), an ellipsoidal ring, a spiral, a triangular chain, a square chain, a rectangular chain, a (regular) polygonal chain, etc. can be used. In addition, the forming/re-forming region 100 can be open or closed at one or a plurality of longitudinal ends, which can be realized, for example, by means of a section, an arc, a spiral or a combined longitudinal extent, etc. Furthermore, the re-forming region 100 can be flat (cf. Fig. 2), which can be realized, for example, by means of a circular area, an ellipsoidal area, a triangular area, a square area, a rectangular area, a (regular) polygonal area, etc. Furthermore, the re-forming region 100 can be irregular.

Temporally after the welding, a weld seam 102 in, in principle, any desired form is produced at the base of the forming/re-forming region 100. The weld seam 102 can be, for example: one or a plurality of welding sections 102 and/or welding regions 102. A welding section 102 or a welding region 102 can be linear, angular and/or bent; closed, open and/or flat; and/or singular and/or combined. Preferably, the weld seam 102 or the weld seams 102 is/are substantially similar to the forming/re-forming region 100. In addition or as an alternative, the weld seam 102 can have one or a plurality of welding spots 102. If it should be necessary, in addition a weld seam 102 or a welding spot 102 can possibly also be provided through the surface 1 1 of the contact device 10.

In accordance with the invention, the forming region 100 is preferably in the form of a re-forming region 100. Re-forming, also referred to as ductile shaping, is a manufacturing method in which, for example, metals or metal alloys are brought in a targeted manner into a different form with plastic deformation, i.e. re-formed. During re-forming, by way of example, a raw material or workpiece which has been subjected to primary forming or has already been re-formed or formed in another way is, if appropriate, only partially re-formed plastically, wherein the raw material or workpiece substantially maintains its mass and its cohesion. A relevant mass of the raw material or workpiece is merely moved during reforming. Re-forming differs from deformation in that a change in shape is achieved in a targeted manner.

Preferably, in each case one circular groove 100 is formed, in particular impressed, into one contact device 10 of the braided wire 1 (cf. Figs 3 and 4) or into in each case one contact device 10 of the braided module connector 1 (cf. Fig. 5). This preferably takes place even upon or during compacting of the relevant longitudinal end section of the braided wire 1 or the module connector 1 to form the contact device 10. Temporally thereafter, the braided wire 1 or the module connector 1 can be laser-welded to the mating contact device 30 via the groove 100. For the case of the module connector 1 , the mating contact device 30 is a section of a connection 3 of a rechargeable battery.

Fig. 1 shows a general embodiment of a square (first approach) contact device 10 comprising a re-forming region 100 in the form of a circular ring (second approach). A side of the mating contact device 30 which has a comparatively large area is designed correspondingly to the side of the contact device 10 which has a comparatively large area. A possible ratio of the cross-sectional height to the cross-sectional thickness in the re-forming region 100 can in this case be applied analogously to Fig. 2, which shows a flat design of the re-forming region 100 (square, rectangular or circular area). The cross section Q ₁₀ of the contact device 10 is in this case welded, in particular laser-welded to a cross section Q ₃₀ of the mating contact device 30 over the re-forming region 100. The cross- sectional area Qi ₀ of the contact device 10 can in this case be smaller, substantially equal in size to or larger than the cross-sectional area Q ₃₀ of the mating contact device 30.

As can be seen in Fig. 2, the welded connection 2 is formed over a cross- sectional dimension Qabioo, in particular a cross-sectional height Qabioo or thickness Qab-ιοο, of the re-forming region 100 or of the contact device 10 in the re-forming region 100 and of a directly adjoining region of the mating contact device 30. The cross-sectional dimension Qab-ιοο is a comparatively small cross- sectional dimension Qab-ιοο of the contact device 10 and can also be referred to as a welding cross-sectional dimension Qab-ιοο, in particular a welding cross- sectional height Qabioo or thickness Qabioo- The cross section Q ₁₀ of the contact device 10 in this case has the cross-sectional dimension Qabi ₀ , in particular a cross-sectional height Qabi ₀ or thickness Qabi ₀ , outside the re-forming region 100. The cross-sectional dimension Qabi ₀ is a comparatively large cross- sectional dimension of the contact device 10.

The cross section Q ₃₀ of the mating contact device 30 has a cross-sectional dimension Qab ₃ o, in particular a cross-sectional height Qab ₃ o or thickness Qab ₃ o, which is preferably overall substantially identical in the mating contact device 30. A preferred ratio of the cross-sectional dimension Qab ₃₀ of the mating contact device 30 to the cross-sectional dimension Qabioo of the re-forming region 100 is 1 .5±0.25 : 1. Other ratios can of course be used. In this case, a cross-sectional area Qi ₀ of the contact device 10 can be larger than a cross-sectional area Q ₃₀ of the mating contact device 30. The cross-sectional area Qi ₀ of the contact device 10 can of course also be substantially equal in size to or smaller than the cross- sectional area Q ₃₀ of the mating contact device 30.

Fig. 3 shows the use of the invention for a compacted section 10 of an electrical connector 1 in the form of a braided wire 1. The compacted section 10 is in this case in the form of a contact device 10 of the braided wire 1 . The re-forming region 100 of the braided wire 1 or the contact device 10 is preferably already established during compacting of the section 10 of the braided wire 1 to form the contact device 10, but can also be introduced only temporally thereafter. After the compacting with re-forming of the section 10 to form the contact device 10 with the re-forming region 100 or after the introduction of the re-forming region 100 into the contact device 10, the braided wire 1 with the contact device 10 can be welded via the re-forming region 100 to the mating contact device 30, which in this case is in the form of a contact 30 of a connection 3. Fig. 4 shows the connector 1 shown in Fig. 3 with an electrical or

electromechanical connector device 40 merely illustrated schematically opposite the compacted contact device 10. The connector device 40 can be in the form of, for example, a plug-type connector 40, a female connector 40, a tab connector 40, a pin connector 40 or a hybrid connector 40, a (built-in) male connector 40, a (built-in) female connector 40, a (floating) clutch, etc. In this case, the connector device 40 is preferably provided once on the connector 1. In addition, in this case the contact device 10 is likewise preferably provided once on the connector 1. Instead of a compacted contact device 10, another contact device 10 can also be used, which applies to all of the embodiments of the invention.

Fig. 5 shows the application of the invention for a module connector 1 according to the invention for a battery 0 or a rechargeable battery 0, wherein the module connector 1 has two contact devices 10 set up in accordance with the invention. A first contact device 10 is in this case weldable or welded to a contact 30 of a connection 3 of a first module 0 of the battery 0 or the rechargeable battery 0, and a second contact device 10 is in this case weldable or welded to a contact 30 of a connection 3 of a second module 0 of the battery 0 or the rechargeable battery 0. The braided wire 1 , which is formed integrally with the contact devices 10 and to which the contact devices 10 belong, extends between the two contact devices 10. In particular in one embodiment of the invention as shown in Fig. 5, it is preferred, owing to a cross-sectional thickness Qab ₃₀ of the contacts 30 of the connections 3 of the modules 0, to reduce an injection depth for a laser in the re-forming region 100 to approximately 0.8 - 1 .2 mm ±0.05 mm, in particular to 0.9-1 .1 mm ±0.05 mm. Other cross-sectional thicknesses Qab ₃₀ of a mating contact device 30 can of course require other cross-sectional thicknesses Qab-ιοο of a re-forming region 100. That is to say that, in accordance with the invention, the re-forming region 100 is used for achieving a thickness ratio Qabioo : Qab ₃₀ between the contact device 10 and the mating contact device 30 which is suitable for welding. In this case, the contact device 10 is preferably provided once (cf. Figs 1 , 3 and 4) or preferably in duplicate (cf. Fig. 5) on the connector 1.

Instead of the connector device 40 illustrated in Fig. 4, the connector 1 according to the invention can of course be connected to an electrical contact in a different way. This can take place in principle in a detachable or non-detachable form. Further possibilities for a detachable form are, for example, screwing or latching, and further possibilities for a non-detachable form are riveting, welding, soldering or adhesive bonding. In addition, compacting of the section 10 of the connector 1 to form a contact device 10, apart from fusing of the individual wires, can likewise be understood to mean a re-forming method. That is to say that the introduction of the re-forming region 100 into the contact device 10 in accordance with the invention can also include the substantially simultaneous compacting of the section 10 of the connector 1 to form the contact device 10.

In accordance with the invention, it is preferred that at least one outer edge of the contact device 10 is substantially aligned with a relevant outer edge of the mating contact device 30. This can in addition relate to two, preferably three or four outer edges of the contact device 10. A preferred form of the re-forming region 100 is a circular ring 100 or an ellipsoidal ring or a square chain or rectangular chain or a combination thereof. In addition, it is possible to provide the re-forming region 100 on an outer edge of the contact device 10, wherein the re-forming region 100 can extend along the outer edge and thus be formed so as to be open at least in sections on the longitudinal side. In this case, the re-forming region 100 can be provided on one, two, three or four outer edges of the contact device 10.

A cross section or a cross-sectional profile of the re-forming region 100 can in principle be selected freely and is advantageously matched to a form of the contact device 10. Thus, side walls of a section of the cross-sectional profile are parallel to one another or assume an angle, wherein a side wall can be arranged perpendicularly with respect to the base of the re-forming region 100. In particular for a laser beam for welding which is not incident perpendicularly on the contact device 10, it may be advantageous to provide a side wall with a slope.

Advantageously, this is an inner side wall, for example in Fig. 1 . Energy from the laser beam can then penetrate during welding into radially outer regions of the contact device 10 and the mating contact device 30, with the result that the welding region is enlarged. In preferred embodiments of the invention, the cross-sectional profile of the reforming region 100 has a substantially identical cross section at all points. A U form, a V form or a mixed form thereof is preferred here. It is of course possible to use a plurality of cross-sectional forms in the re-forming region 100. In addition, the base of the re-forming region 100 can be provided parallel to a large-area outer side of the contact device 10 (cf. Fig. 2) or at an angle thereto. Such a base can be combined with an above-mentioned side wall of the reforming region 100. Furthermore, both the base and one or both side walls of the re-forming region 100 can be flat or curved and/or rough or smooth.