EP2946395A1

EP2946395A1 - Contact element, relay comprising a contact element and method for producing a contact element

Info

Publication number: EP2946395A1
Application number: EP14700502.9A
Authority: EP
Inventors: Markus Gutmann; Andreas Maag; Manfred Stoll; Guenter Weik
Original assignee: Tyco Electronics Austria GmbH; Inovan GmbH and Co KG
Current assignee: Tyco Electronics Austria GmbH; Inovan GmbH and Co KG
Priority date: 2013-01-16
Filing date: 2014-01-15
Publication date: 2015-11-25
Also published as: DE102013200607A1; WO2014111416A1

Abstract

The invention relates to a contact element (1) for repeated, releasable contacting of a counter-contact element in a contact direction (4), a relay having a contact element (1) and a method for producing a contact element (1). An object of the present invention is to provide a cost-effective contact element which is particularly suitable for use in relays having force-guided contacts ("safety relays") or other safety-relevant components. Another object of the invention is to provide a method for producing such a contact element. The object is achieved with a contact element (1) in which a base portion (2) and a contact portion (3) are connected to each other in a positive-locking manner. A method according to the invention for producing such a contact element (1) comprises the steps of placing (90) a positive-locking element (50, 50d) of a first portion (93) on a second portion (92) and producing a positive-locking connection between the first portion (93) and the second portion (92).

Description

Contact element, relay comprising a contact element and method for producing a contact element

The invention relates to a contact element for repeated, releasable contacting of a counter-contact element in a contact direction, comprising a contact portion for the contacting and a base portion which is connected to the contact portion in a non- releasable manner for connection to an electrical circuit, the contact portion being arranged at a contact-side end of the contact element and the base portion being arranged at a connection-side end of the contact element opposite the contact-side end with respect to the contact direction. Furthermore, the invention relates to a relay having such a contact element. Furthermore, the invention relates to a method for producing such a contact element.

Contact elements as used, for example, in relays, in most cases have a base portion for connection to an electrical circuit and a contact portion which is connected to the base portion in a non-releasable manner for repeated, releasable contacting of a counter- contact element. The base portion may be of a cost-effective and highly conductive material, such as copper. The contact portion should also have good electrical conductivity and should not become welded to the counter-contact element when it comes into contact therewith or change during the contacting. Suitable materials for the contact portion include in particular silver or silver-based materials, such as AgSnO or AgNi. These materials are applied to the base portion as a layer. Owing to the repeated and mostly abrupt loading during contacting, and owing to thermal influences, such a contact portion may become released from the base portion, which cannot be tolerated in particular with relays having force-guided contacts ("safety relays").

As an alternative to the above-mentioned two-part embodiments, single-part embodiments of the material may also be used for the contact portion of the two-part variant. However, since these mostly contain silver, such contact elements are significantly more expensive than two-part embodiments.

An object of the present invention is to provide a cost-effective contact element, in particular a contact element for use in relays having force-guided contacts ("safety relays") or other safety-relevant components. Another object of the invention is to provide a method for the production of such a contact element. The object is achieved with a contact element in which the base portion and the contact portion are connected to each other in a positive-locking manner. A method according to the invention for producing such a contact element comprises the steps of placing a positive-locking element of a first portion on a second portion and producing a positive- locking connection between the first and the second portion.

The positive-locking connection ensures that the base portion cannot become disengaged from the contact portion in the contact direction. It thus blocks in particular a relative movement in the contact direction. The positive-locking connection prevents the contact portion from falling towards the counter-contact element. In contrast to the previously used connection between the two portions, such a positive-locking mechanical connection cannot be influenced by the repeated, releasable contacting and the effects which occur.

The method according to the invention constitutes a possibility for producing such a contact element. As an alternative to the method shown, however, other methods can also be used to produce a contact element according to the invention.

Advantageous developments and embodiments of the invention which can be freely combined are described below.

The base portion and the contact portion may engage one in the other in a positive- locking manner. With such an embodiment, other elements, such as screws, nails, pins or other connection elements can be dispensed with. This simplifies the production, the assembly and the recycling.

The contact portion and the base portion can be connected to each other not only in a non-releasable manner, but also in a non-movable manner.

The contact element may comprise only the base portion and the contact portion. With such an embodiment, the production can be simplified. Furthermore, such an embodiment may prevent the contact element from becoming unusable owing to faults in other components.

The base portion and/or the contact portion may each have positive-locking elements. In a particularly advantageous embodiment, both the base portion and the contact portion have positive-locking elements. Such positive-locking elements may be arranged on the base portion and/or on the contact portion. In particular they may be integral with the base portion and/or the contact portion or portions of the base portion and/or the contact portion. It is possible to use, for example, surfaces or edges which extend in an oblique or perpendicular manner relative to the contact direction as positive-locking elements. A corner or a point may also act as a positive-locking element.

In a particularly advantageous embodiment, the base portion and the contact portion each have positive-locking elements, the positive-locking elements being constructed so as to complement each other. They may be constructed so as to complement each other only partially or also to complement each other completely. This embodiment ensures a good connection between the base portion and contact portion. A production or assembly may also be simplified by means of such an embodiment. Faces or portions of two components which are in mutual abutment may in each case be constructed to be the same. Lateral elements may be used as positive-locking elements. They may have been plastically shaped, for example, they may have been milled, bent and/or rolled. Therefore, the lateral elements may be shaped, in particular plastically shaped, lateral elements.

The contact portion and/or the base portion may be shaped, in particular plastically shaped, components. They may have been milled, bent and/or rolled. The shaping may also have been carried out only in portions.

One possible advantageous embodiment of a contact element according to the invention makes provision for the base portion and/or the contact portion to extend in a connection region in an extent direction into the other contact element portion in each case, that is to say, the contact portion or the base portion, and for a thickness of the inwardly extending portion measured in a thickness direction perpendicular relative to the contact direction to increase in the extent direction in the connection region. An overall material thickness of the inwardly extending portion, composed of the individual material thicknesses measured in the thickness direction does not in this instance necessarily also have to increase. In one possible embodiment, it is conceivable for the overall material thickness of the inwardly extending portion to decrease, whilst the thickness of the inwardly extending portion increases. In order to achieve a positive-locking connection, the clearance of the receiving portion should increase in the extent direction in the connection region. The overall material thickness of the receiving portion may increase in the connection region in the extent direction or remain the same. However, in order to compensate for the increasing thickness of the inwardly extending portion, in an advantageous embodiment the overall material thickness of the receiving portion decreases in the extent direction. A thickness of the receiving portion may increase, decrease or remain the same in the extent direction.

According to an advantageous embodiment, a continuation of the base portion or the contact portion extends in an extent direction into a receiving member of the other contact element portion in each case, a thickness of the continuation measured in a thickness direction perpendicular relative to the contact direction and a clearance of the receiving member also measured in the thickness direction increasing in the extent direction. An overall material thickness of the continuation may increase, decrease or remain the same in the extent direction. An overall material thickness of the material which surrounds the receiving member and which forms the receiving member, which thickness is also measured in the extent direction, may increase, decrease or remain the same. A thickness of the contact portion element with the receiving member may increase, decrease or remain the same in the extent direction.

In another advantageous embodiment, the base portion or the contact portion extends in an extent direction into the other contact element portion in each case, a cross-section surface-area of the inwardly extending portion measured transversely relative to the contact direction increasing in the extent direction in a connection region. In a similar manner, a clear cross-section surface-area of the receiving portion measured transversely relative to the contact direction may also increase in the extent direction. The overall material cross-section surface-areas of the inwardly extending portion or the receiving portion measured transversely relative to the contact direction may increase, decrease or remain the same in the extent direction in the connection region. The overall material cross-section surface-areas and overall cross-section surface-areas are calculated in this instance by the addition of individual material cross-section surface-areas or cross-section surface-areas.

In an advantageous embodiment, a continuation of the base portion or the contact portion extends in an extent direction into a receiving member of the other contact element portion in each case, a cross-section surface-area of the continuation measured transversely relative to the contact direction increasing in the extent direction. An overall material cross-section surface-area of the continuation may in this instance increase, decrease or remain the same. At the same time, a clear cross-section surface-area of the receiving member measured perpendicularly relative to the contact direction may decrease in the extent direction. An overall cross-section surface-area and/or overall material cross-section surface-area of the material surrounding the receiving member, which surface-area is measured perpendicularly relative to the contact direction, may increase, decrease or remain the same in the extent direction.

The mentioned cross-section surface-areas, material cross-section surface-areas, overall cross-section surface-areas and overall material cross-section surface-areas may in particular be measured perpendicularly relative to the contact direction.

The receiving member may be a receiving member which is open at one side in one direction and which is open in the direction but limited or closed counter to the direction. In particular, the receiving member may be a receiving member which is open at one side in the contact direction. The receiving member may be open in the contact direction and closed counter to the contact direction. Alternatively, the receiving member may be closed in the contact direction and open counter to the contact direction. In and counter to other directions, the receiving member may be open or limited. The receiving member may have a continuous base face, in particular a continuous base face which is perpendicular relative to the contact direction.

A plurality of continuations which together protrude into a receiving member and thereby produce a positive-locking connection may also be provided. In this instance, a spacing of two outer faces located on different continuations should increase in the extent direction. The positive-locking connection according to the invention may be achieved by means of an undercut portion on the contact portion or on the base portion which cooperates with the other contact element portion in each case. Such an undercut portion may be located in a connection region of the two contact element portions. An undercut portion extends transversely relative to the contact direction behind a corresponding counter-element on the other contact element portion, for example, a step or a stop.

The base portion and the contact portion may be connected by means of a dovetail connection. With such an embodiment, the material of a first portion expands, as does the associated complementary recess of a second portion in two mutually opposed transverse directions which extend transversely relative to the contact direction in a continuous manner, in particular in a uniform manner as far as the end. Such an embodiment may be particularly easy to produce and to assemble. Furthermore, it ensures a good and reliable connection. In particular, other connection mechanisms can be dispensed with. In a second transverse direction transverse relative to the first two transverse directions and transverse relative to the contact direction, the dovetail profile may extend continuously, for example, from one end to the other end.

The base portion may have securing elements or securing portions for securing to external elements or to elements of the electrical circuit. For example, there may be provided a rivet portion which enables securing in the manner of a rivet. In order to simplify such a riveting operation, there may be provided recesses which simplify plastic deformation.

The base portion may have support portions or support elements, such as shoulders, which support the base portion and consequently the contact element so that a force is absorbed in one direction, in particular in the contact direction, and the contact element is introduced.

The base portion and/or the contact portion may be solid components. In comparison with other embodiments, such as metal sheets or pipes, a solid component is very stable and difficult to deform.

The contact portion may have for contacting an end face which is perpendicular relative to the contact direction and which enables a secure contacting since it is in planar abutment with the counter-contact. An electrically conductive contact face which is larger in comparison with a round end face may also be achieved thereby. In particular, such an end face may be continuous, that is to say, have no holes. This increases the electrically conductive contact face and increases the stability since deformation is more difficult.

The contact element may have a protective layer. Such a protective layer may protect, for example, from corrosion, abrasion or from contact with harmful substances or materials. In particular, the end face may have a protective layer. A plurality of protective layers may also be provided.

In particular on outer faces, layers with other functions may also be provided. Such a layer may, for example, be a contact layer which facilitates contacting or minimises transition resistance. The protective layer or another layer may contain gold or completely comprise gold.

An intermediate layer may be arranged between the base portion and the contact portion. An intermediate layer may improve the transition resistance or enable better connection, in particular a material connection, between the base portion and the contact portion. Using the intermediate layer, in particular a materially integral connection may also be produced. For example, a solder may connect the base portion to the contact portion. In an advantageous embodiment, the base portion and the contact portion are connected to each other only mechanically. Another connection, for example, a materially integral connection, such as the one which can be produced, for example, by means of welding or soldering, does not have to be present since the positive-locking connection reliably connects the base portion to the contact portion. Surfaces of the base portion may be in abutment with faces of the contact portion and/or be in pressing contact therewith. Such a mechanical connection may, for example, be produced by means of rolling, bending or riveting.

The positive-locking connection can block movements not only in the contact direction, but also in other directions. The positive-locking connection may, for example, act in and/or counter to a first transverse direction transverse relative to the contact direction. In and/or counter to a second transverse direction which extends transversely relative to the contact direction and transversely relative to the first contact direction, the movement may also be blocked. Alternatively, there may be no blocking in the second transverse direction. A contact element which is constructed in this manner may, for example, be produced by being fitted one inside the other in the second transverse direction. Regardless of this, other connection mechanisms, such as frictional connections or materially integral connections, may also be present in other directions. A relay according to the invention comprises at least one contact element according to the invention. In particular, this may be a safety relay.

In an advantageous embodiment of the method according to the invention, the positive- locking element of the first portion acting in the contact direction is inserted into a receiving member or an opening of the second portion. This may, for example, be a groove-like or vessel-like receiving member. The receiving member may in particular be a receiving member which has already been mentioned above and which is open at one side in the contact direction. In this instance, the first portion may, for example, be placed on a base face of the second portion. A receiving member or opening may be at least partially shaped in a second step in order to produce a positive-locking connection. In this instance, the receiving member or the opening may be at least partially decreased or closed. In order to produce the positive- locking connection, lateral elements of the second portion may be bent or shaped. In such an embodiment, the method may be implemented in a particularly simple manner.

The positive-locking connection may be produced by means of mechanical processing. One of the components may be plastically deformed at least in the region of the positive- locking connection. The other component may also be mechanically processed, in particular plastically formed. One or both components may be milled, forged, rolled, bent, riveted or plated. In particular, lateral elements may be plastically shaped.

In a preferred embodiment, the two components are connected by means of the mechanical processing, in particular by means of plating, not only in a positive-locking manner, but also in a metallurgical manner. This leads to a particularly secure and consequently particularly reliable connection. In a corresponding advantageous contact element, a first and a second portion are connected to each other not only in a positive- locking manner, but also in a metallurgical manner.

When the positive-locking connection is produced between the first and second portion, a positive-locking element may be produced on the second portion. This positive-locking element which has been produced may in particular cooperate with the positive-locking element of the first portion and/or be constructed so as to complement it.

The first portion and/or the second portion may additionally be annealed. Owing to the annealing, the connection can be improved and/or tensions can be reduced. In particular, the first portion and the second portion may be annealed together in the connected state.

Other method steps which may be carried out include, for example, the application of a layer, such as the above-described protective layer or intermediate layer, to the first and/or the second portion. Alternatively or additionally, the first and/or the second portion may already have such protective layers before the method is carried out. A method according to the invention may in particular also comprise the step of producing the first portion with a positive-locking element which acts in the contact direction. The second portion may also be produced during the method. In particular the method may comprise the production of the second portion with a receiving member which is open in the contact direction. The production of the first and/or the second portion may, for example, be carried out by means of mechanical processing such as rolling, shaping, pressing or plating. In an advantageous embodiment of the method, after the positive-locking connection has been produced, subsequent processing of the profile is carried out. Possible subsequent processing steps are the fine profiling of the radii or the implementation of annealing processes. In a particularly advantageous embodiment of the method, the first portion and the second portion are strands which extend perpendicularly relative to the contact direction. After the production of the positive-locking connection between the two strands, individual contact elements according to the invention can be separated, for example, cut, from a whole strand which has been produced. The production of the positive-locking connection may be produced along the entire length of the first and second strand at the same time, or continuously at a single connection location which moves in the strand direction. In this embodiment of the method, the whole strand thus forms a strand which is composed of part-strands. From such a strand, the contact elements according to the invention can be produced in a simple manner.

The invention further relates to a strand for producing contact elements from two part- strands which are connected to each other in a positive-locking manner, contact elements according to the invention being able to be separated from the strand. In an embodiment of the strand, at least one part-strand may be shaped at least in the region of the positive- locking connection. Both part-strands may also have been shaped at least in the region of the positive-locking connection. Shaping may in particular be plastic shaping, for instance, by means of milling, rolling, pressing and/or bending.

The contact element according to the invention may also be produced by means of other methods. For example, the base portion could be riveted or pressed into the contact portion. Of course, the reverse procedure is also conceivable. Furthermore, a contact element according to the invention could be produced, for example, by pouring liquid material into an opening and subsequent solidification.

The invention is described below with reference to embodiments and developments which are each advantageous per se and which can be freely combined with each other. The same reference numerals indicate elements which are identical.

In the drawings: is a schematic sectioned illustration of a first embodiment of a contact element according to the invention;

is a schematic sectioned illustration of a second embodiment of a contact element according to the invention;

is a schematic sectioned illustration of a third embodiment of a contact element according to the invention;

is a schematic sectioned illustration of a fourth embodiment of a contact element according to the invention;

is a schematic sectioned illustration of a fifth embodiment of a contact element according to the invention;

is a schematic sectioned illustration of a sixth embodiment of a contact element according to the invention;

is a schematic sectioned illustration of a seventh embodiment of a contact element according to the invention;

is a schematic sectioned illustration of an eighth embodiment of a contact element according to the invention;

is a schematic sectioned illustration of a first step of an embodiment of a method according to the invention for producing a contact element;

is a schematic sectioned illustration of a second step of an embodiment of a method according to the invention for producing a contact element;

is a whole strand from an advantageous method according to the invention.

Figure 1 shows a first embodiment 1 a of a contact element 1 according to the invention. The contact element 1 , 1 a comprises a base portion 2, which can be connected to an electrical circuit. The base portion 2 may, for example, comprise copper or contain copper. The base portion 2 is arranged at a connection-side end A of the contact element 1 , 1 a. A contact portion 3 is connected to the base portion 2 in a non-releasable and non-movable manner and arranged at a contact-side end K of the contact element 1 , 1 a. The contact- side end K and the connection-side end A are opposite each other with respect to the contact direction 4. The contact-side end K is arranged in a state opposed to the connection-side end A, that is to say, with respect to the contact direction 4. The contact- side end K is the end located in the contact direction, the connection-side end A is the end located counter to the contact direction 4.

The contact portion 3 also comprises a conductive material. It is of a material which is highly suitable for the contacting. For example, it may comprise silver or silver-containing materials, such as AgSnO or AgNi. Materials for the contact portion should have good conductivity and not become welded to the counter-contact element or react therewith.

The base portion 2 is connected to the contact portion 3 in a positive-locking manner. A relative movement of the two in the contact direction 4 is thereby prevented.

The first embodiment 3a of a contact portion 3 shown here projects in an extent direction 6, which is opposed to the contact direction 4, into a first embodiment 2a of a base portion 2. It is shown here that a continuation 30 of the contact portion 3, 3a extends into a receiving member 20 of the base portion 2, 2a. The thickness 31 of the continuation 30, measured in a thickness direction 7 perpendicular relative to the contact direction 4, increases in the extent direction 6 in the connection region 40. A clearance 21 of the receiving member 20 of the base portion 2, 2a also measured in the thickness direction 7 also increases in the extent direction 6 in the connection region 40. At the same time, the thickness 22 of the base portion 2, 2a measured in the thickness direction 7 also increases in the connection region 40.

The positive-locking connection between the base portion 2, 2a and the contact portion 3, 3a is brought about only by the base portion 2, 2a and the contact portion 3, 3a. No other elements are present.

An end face 5 which extends perpendicularly relative to a contact direction 4 serves to repeatedly, releasably connect a counter-contact element (not shown) in the contact direction 4. Lateral elements 92a, 92b act as positive-locking elements 50. The lateral elements 92a, 92b are shaped lateral elements 92a', 92b' which have been produced by means of plastic shaping, such as milling, rolling, bending, pressing or the like. The continuation 30 may be understood to be a first positive-locking element 50a, the receiving member 20 may be understood to be a second positive-locking element 50b. The two positive-locking elements 50a, 50b are constructed so as to complement each other. The contact portion 3, 3a has on the continuation 30 a plurality of undercut portions 60 which cooperate with the receiving member 20 of the base portion 2.

Figure 2 shows a second embodiment 1 b of a contact element 1 according to the invention. It comprises a second embodiment 2b of a base portion 2 and a second embodiment 3b of a contact portion 3. In a similar manner to the first embodiment 1 a illustrated in Figure 1 , in the second embodiment 1 b the base portion 2 is also connected to the contact portion 2 by means of a dovetail connection 70. In this instance, however, a continuation 24 of the base portion 2, 2b extends into a receiving member 34 of the base portion 3, 3b, the construction of the dovetail connection 70 is therefore precisely transposed with respect to the first embodiment 1 a. The thickness 25 of the continuation 24 measured in a thickness direction 7 which extends perpendicularly relative to the contact direction 4 increases in the connection region 40 in an extent direction 6 which extends in this instance in the contact direction 4. At the same time, however, the thickness 36 of the contact portion 3, 3b decreases in the connection region 40.

The base portion 2, 2b is connected to the contact portion 3, 3b only mechanically. Other connection mechanisms, such as soldering, welding or the like, are not necessary in order to ensure reliable retention and to prevent the contact portion 3, 3b from falling off the base portion 2, 2b in the contact direction 4. In particular, no materially integral connection is required. In the embodiment 1 b shown here, the base portion has an undercut portion 60 which cooperates with the contact portion 3, 3b. The undercut portion 60 cooperates at an outer face 24a as a first positive-locking element 50a with an inner face 34a of the receiving member 34 which acts as a second positive-locking element 50b. Figure 3 shows a third embodiment 1 c of a contact element 3 having a base portion 2, 2c and a contact portion 3, 3c. The two contact element portions 2, 3 are again connected to each other in a positive-locking manner. This positive-locking engagement is produced by means of an undercut portion 60. In contrast to the two previous embodiments 1 a, 1 b, however, there is only a single undercut portion 60. This extends in a transverse direction 8, which extends transversely relative to the contact direction 4 and parallel with the thickness direction 7. A first lateral face 60a which extends in an oblique manner with respect to the contact direction 4 forms, together with an obliquely extending inner face 20a of the receiving member 20 of the base portion 2, 2c, positive-locking elements 50. A second lateral face 60b of the continuation 30 of the contact portion 3, 3c extends parallel with the contact direction 4 and thus produces no positive-locking connection in the contact direction with the second inner face 20b of the receiving member 20 in abutment therewith.

Figure 3 shows a receiving member 20' which is open at one side in one direction, in particular a receiving member 20" which is open at one side in the contact direction 4. This is open in the contact direction 4; counter to the contact direction 4, the receiving member 20 is delimited by a base face 20f. In and counter to the thickness direction 7, the receiving member 20, 20', 20" is delimited. In and counter to a direction which extends perpendicularly relative to the plane of the drawing, the receiving member 20, 20' 20" may be delimited or open.

Figure 4 shows a fourth embodiment 1 d of a contact element 1 according to the invention. In contrast to the previous embodiments, a boundary region 80 between the base portion 2 and the contact portion 3 has no sharp edges, but instead extends in a curved manner. The boundary line 81 shown here is a boundary line 81 a which extends in a stepless manner. The boundary line 81 drawn in cross-section is part of the boundary face 82 between the base portion 2, 2d and contact portion 3, 3d. Such a boundary face 82 may also extend in a stepless manner. It may thus be a boundary face 82a which extends in a stepless manner. The embodiment 1 d shown in Figure 4 may, for example, be secured to the base portion 2, 2d by hammering or riveting the contact portion 3d into the base portion 2, 2d. A production in which the contact portion 3, 3d is cast in the base portion 2, 2d may also produce such an embodiment or another embodiment shown.

The base portion 2, the contact portion 3 and the entire contact element 1 , 1 d are all solid components 45, whereby such a contact element 1 , 1 d is particularly stable and resilient. Figure 5 shows a fifth embodiment 1 e of a contact element 1 . A continuation 30 of the contact element 3, 3e which comprises a first continuation portion 30a and a second continuation portion 30b extends into a receiving member 20 of the base portion 2, 2e. Between the two continuation portions 30a, 30b is a hollow space 83. The thickness 31 of the continuation 30 increases in the extent direction 6, the thicknesses again being measured in a thickness direction 7 which is perpendicular relative to the contact direction 4. The clearance 21 of the receiving member 20 of the base portion 2, 2e increases to the same extent. However, the overall material thickness of the continuation 30 which is composed of the first material thickness 31 a and the second material thickness 31 b decreases in the extent direction 6. The overall material thickness of the base portion 2, 2e which is composed of the first material thickness 22a and the second material thickness 22b also decreases in the extent direction 6. However, the thickness 22 of the base portion 2, 2e remains substantially the same in this region. In the same manner as the thicknesses, the material thicknesses and the overall material thicknesses which are shown in the Figures, the cross-section surface-areas, the material cross-section surface-areas and the overall material cross-section surface-areas may also increase, decrease or remain the same. In place of the other Figures, this is explained with reference to the embodiment 1 e of Figure 5. The contact element 1 e shown may be formed in such a manner that the cross-section thereof shown in Figure 5 does not change in the direction directed out of the plane of the drawing. Alternatively, the cross- section could also be unchanged in the event of a rotation. In both cases, the above statements relating to the thicknesses 31 , 22, the material thicknesses 31 a, 31 b, 22a, 22b and the overall material thicknesses would apply in a similar manner to the cross-section surface-areas 131 , 122, the material cross-section surface-areas 131 a, 131 b, 122a, 122b and the overall material cross-section surface-areas. The overall material cross-section surface-areas are composed in this instance of the individual material cross-section surface-areas. If the two continuation portions 30a, 30b were not connected to each other in the centre, they would each form individual continuations. For a positive-locking connection which acts in the contact direction 4, the spacing of the two outer faces of the continuations would have to increase in the extent direction 6. This spacing would then correspond to the thickness 31 of the continuation 30 shown here. Figure 6 shows a sixth embodiment 1 f of a contact element 1 . In this embodiment, both the thickness 22 of the base portion 2, 2f and the overall material thickness of the base portion 2, 2f which is composed of the first material thickness 22a and the second material thickness 22b increase in the extent direction 6, at least in the connection region 40. The thickness 31 of the continuation 30 of the base portion 3, 3f also increases in the extent direction 6, as does the clearance 21 of the receiving member 20 of the base portion 2, 2f.

Figure 7 shows a seventh embodiment 1 g of a contact element 1 . There is an intermediate layer 10 between the base portion 2, 2g and the contact portion 3, 3g. This may be used for connection, for example, to connect the base portion 2, 2g to the contact portion 3, 3g in a materially integral manner. By means of the intermediate layer 10, a transition resistance between the base portion 2, 2g and the contact portion 3, 3g may also be reduced. The contact element 1 , 1 g has a securing element 40 in the form of a securing portion 41 , by means of which it can be secured to other elements. This is a rivet portion 42 which can be riveted. In a lower side 1 1 which is located at the connection-side end A, the contact element 1 , 1 g has for this purpose a recess 12 which facilitates plastic deformation.

For support on external elements, such as a retention member, the contact element 1 , 1 g has support elements 46 in the form of shoulders 47. These act in the contact direction 4 and can block a movement of the contact element 1 , 1 g counter to the contact direction 4. Figure 8 shows an eighth embodiment 1 h of a contact element 1 . The connection between the base portion 2, 2h and the contact portion 3, 3h is produced in this instance by means of a receiving member 20, 20t which is T-shaped in cross-section together with a continuation 30, 30t which is T-shaped in cross-section. In addition, the contact element 1 , 1 h has a protective layer 13 on the end face 5. Such a protective layer may, for example, provide protection against abrasion during contacting or against corrosion. It comprises, for example, gold.

Figures 9 and 10 schematically illustrate a method according to the invention for producing a contact element 1 . Figure 9 shows a first step 90, in which a positive-locking element 50, 50d of a first portion 93 is placed on a second portion 92. A continuation 130 of the first portion 93 which acts as a positive-locking element 50, 50d is inserted into a vessel-like receiving member 120 of the second portion 92. The vessel-like receiving member 120 is open in the contact direction only in the contact direction 4 but not open counter to the contact direction 4. Counter to the contact direction 4, it is delimited by a base face 120f perpendicular relative to the contact direction 4. Therefore, it is a receiving member 120' which is open at one side in one direction, in particular a receiving member 120" which is open at one side in the contact direction 4. In the direction which extends perpendicularly relative to the plane of the drawing, the receiving member 120 is open at both sides.

Figure 10 illustrates a second step 91 of the method, in which a positive-locking connection is produced between the first portion 93 and the second portion 92. In this instance, the second portion 92 is at least partially plastically deformed by lateral elements 92a, 92b being formed on the positive-locking element 50 of the first portion 93. This may be carried out, for example, by means of plating, bending, rolling or milling. The lateral elements 92a', 92b' formed in this manner also form positive-locking elements 50, 50c which, together with the positive-locking element 50, 50d of the first portion, produce a positive-locking connection and consequently prevent the first portion 93 from being able to fall off the second portion 92 in the contact direction 4. Advantageously, the mechanical processing operation, in particular plating, is carried out in such a manner that the two portions are connected to each other not only in a positive-locking manner but also in a metallurgical manner.

The first portions 93 and second portions 92 shown in Figures 9 and 10 may be a base portion 2 and a contact portion 3 of a contact element 1 .

In a preferred embodiment of the method, both the first portion 93 and the second portion 92 are strand-like. The two strands 92', 93' may as a whole be fitted to each other in a single step. Alternatively, the positive-locking connection between the two is continuously produced at a changing location. A contact element according to the invention can be separated from the resulting whole strand 95. The whole strand 95 in other words forms a new strand 96 which is composed of the part-strands 97, 98. In the region of the positive- locking connection, a part-strand 97 is shaped. The other part-strand 98 is also at least slightly shaped. Figure 1 1 shows such a whole strand 95 or strand comprising the first portion 93, 93' and the second portion 92, 92', that is to say, the part-strands 97, 98. Contact elements 1 according to the invention can be separated, for example, by means of cutting or sawing, from this strand 96.

List of reference numerals

1 Contact element

1 a, b, c, d, e, f, g, h Embodiments of a contact element

2 Base portion

2a, b, c, d, e, f, g, h Embodiments of a base portion

3 Contact portion

3a, b, c, d, e, f, g, h Embodiments of a contact portion

4 Contact direction

5 End face

6 Extent direction

7 Thickness direction

8 Transverse direction

10 Intermediate layer

1 1 Lower side

12 Recess

13 Protective layer

20 Receiving member in the base portion

20' Receiving member which is open at one side in one direction

20" Receiving member which is open at one side in the contact direction

20a Obliquely extending inner face of the receiving member

20b Second inner face of the receiving member

20f Base face

20t T-shaped receiving member

21 Clear width of the receiving member of the component

22 Thickness of the base portion

22a, b First, second material thickness

24 Continuation of the base portion

24a Outer face

25 Thickness of the continuation of the base portion

30 Continuation of the contact portion

30a, b Continuation portions

31 Thickness of the continuation of the contact portion

31 a, b First, second material thickness

34 Receiving member of the contact portion

34a Inner face of the receiving member of the base portion

36 Thickness of the contact portion

40 Securing element

41 Securing portion

42 Rivet portion

45 Solid component

46 Support element

47 Shoulders

50 Positive-locking element

50a, b First, second positive-locking element

50c, d Positive-locking elements

60 Undercut portion

60a Obliquely extending lateral face of the undercut portion

60b Second lateral face of the undercut portion

70 Dovetail connection

80 Boundary region

81 Boundary line 81 a Boundary line extending in a stepless manner

82 Boundary face

82a Boundary face extending in a stepless manner

83 Hollow space

90 First step

91 Second step

92 Second portion

92a, b Lateral elements of 92

92a',b' Shaped lateral elements

92' Strand

93 First portion

93' Strand

95 Whole strand

96 Strand

97, 98 Part-strands

120 Receiving member

120' Receiving member which is open at one side in one direction

120" Receiving member which is open at one side in the contact direction

120f Base face

122 Cross-section surface-area

122a, b Material cross-section surface-area

130 Continuation

131 Cross-section surface-area of the continuation

131 a, b Material cross-section surface-area

A Connection-side end

K Contact-side end

Claims

1 . Contact element (1 ) for repeated, releasable contacting of a counter-contact element in a contact direction (4), comprising a contact portion (3) for the contacting and a base portion (2) which is connected to the contact portion (3) in a non-releasable manner for connection to an electrical circuit, the contact portion (3) being arranged at a contact-side end (K) of the contact element (1 ) and the base portion (2) being arranged at a connection-side end (A) of the contact element (1 ) opposite the contact-side end (K) with respect to the contact direction (4), characterised in that the base portion (2) and the contact portion (3) are connected to each other in a positive-locking manner.

2. Contact element (1 ) according to claim 1 , characterised in that the base portion (2) and the contact portion (3) engage one in the other in a positive-locking manner.

Contact element (1 ) according to either claim 1 or claim 2, characterised in that the base portion (2) and the contact portion (3) have positive-locking elements (50, 50a, 50b, 50c, 50d).

Contact element (1 ) according to any one of claims 1 to 3, characterised in that the contact portion (3) or the base portion (2) has an undercut portion (60) which cooperates with the other portion (2, 3).

Contact element (1 ) according to any one of claims 1 to 4, characterised in that the base portion (2) and the contact portion (3) are connected by means of a dovetail connection (70).

Contact element (1 ) according to any one of claims 1 to 5, characterised in that an intermediate layer (10) is arranged between the base portion (2) and the contact portion (3).

Contact element (1 ) according to any one of claims 1 to 6, characterised in that the base portion (2) and the contact portion (3) are connected to each other only mechanically.

8. Contact element (1 ) according to any one of claims 1 to 7, characterised in that the base portion (2) and/or the contact portion (3) has/have shaped lateral elements (92a', 92b') which act as positive-locking elements (50, 50c).

9. Relay, in particular a safety relay, characterised in that it comprises at least one contact element (1 ) according to any one of claims 1 to 8.

10. Method for producing a contact element (1 ) having a base portion (2) and a contact portion (3), characterised in that it comprises the steps of:

- placing a positive-locking element (50, 50d) of a first portion (93) on a second portion (92); and

producing a positive-locking connection between the first portion (93) and the second portion (92).

1 1 . Method according to claim 10, characterised in that lateral elements (92a, 92b) of the second portion (92) are bent over.

12. Method according to either claim 10 or claim 1 1 , characterised in that the two portions (92, 93) are connected to each other in a positive-locking manner by means of mechanical processing, in particular bending or rolling.

13. Method according to either claim 10 or 1 1 , characterised in that the two portions (92, 93) are connected to each other by means of plating in a positive-locking and metallurgical manner.

14. Method according to any one of claims 10 to 13, characterised in that the first portion (93) and the second portion (92) are strands (92', 93') which extend perpendicularly relative to the contact direction (4) and, after a positive-locking connection has been produced between both strands (92', 93'), the individual contact elements (1 ) are separated, in particular cut, from the whole strand (95) which has been produced.

15. Strand (96) for producing contact elements from two part-strands (97, 98) which are connected to each other in a positive-locking manner, characterised in that contact elements (1 ) according to any one of claims 1 to 8 can be separated from the strand (1 ).