WO2013156379A1

WO2013156379A1 - Contact assembly with at least two contact arms, and contact arrangement comprising a contact assembly with at least two contact arms

Info

Publication number: WO2013156379A1
Application number: PCT/EP2013/057564
Authority: WO
Inventors: Martin Listing; Walter SAENGER; Frank Wittrock
Original assignee: Tyco Electronics Amp Gmbh
Priority date: 2012-04-16
Filing date: 2013-04-11
Publication date: 2013-10-24
Also published as: DE102012103258B4; DE102012103258A1

Abstract

The invention relates to a contact assembly (1) for electrically contacting a counter-contact surface (11), comprising at least two elastically deflectable contact arms (2) with a contact point (8) for contacting the counter-contact surface (11). Further, the invention relates to a contact arrangement (10) comprising at least one such contact assembly (1) and a counter- contact surface (11) which is electrically contacted by the contact points (8). With known contact assemblies (1) with elastically deflectable contact arms (2), vibrations cause a relative movement of the contact point (8) and the counter-contact surface (11), so that they become damaged over time and their electrical properties may change detrimentally. It is therefore the aim of the present invention to provide a contact assembly (1) which ensures reliable, uniform electrical contacting of the contact assembly (1) with a counter- contact surface (11) even in the case of long use under vibration stress. This is achieved according to the invention in that at least one contact arm (2) forms a control arm (3) and at least one contact arm (2) forms a follower arm (4), the follower arm (4) being coupled in deflection-following manner to the control arm (3) and deflection of the control arm (3) inevitably leading to deflection of the follower arm (4).

Description

Contact assembly with at least two contact arms, and contact arrangement comprising a contact assembly with at least two contact arms

The invention relates to a contact assembly for electrically contacting a counter-contact surface, comprising at least two elastically deflectable contact arms with a contact point for contacting the counter-contact surface. Further, the invention relates to a contact arrangement comprising at least one such contact assembly and a counter-contact surface which is electrically contacted by the contact points.

Contact assemblies with elastically deflectable contact arms are known. The contact arms are usually arranged parallel or at a slight angle to a counter-contact surface, and electrically contact the counter-contact surface at a contact point. The contact assembly and the counter-contact surface are often subjected to vibrations. It is therefore necessary for the contact arms to exert a relatively high normal force on the counter-contact surface at the contact points in order not to lose the contact between the contact point and the counter-contact surface. The vibrations cause a relative movement of the contact point and the counter-contact surface, so that they become damaged over time and their electrical properties may change detrimentally. For example, the contact resistance may change significantly, in particular may deteriorate. Also a contact layer or protective layer fixed to the counter-contact surface can be rubbed off thereby.

It is therefore the aim of the present invention to provide a contact assembly which ensures reliable, uniform electrical contacting of the contact assembly with a counter-contact surface even in the case of long use under vibration stress.

This is achieved according to the invention in that at least one contact arm forms a control arm and at least one contact arm forms a follower arm, the follower arm being coupled in deflection-following manner to the control arm and deflection of the control arm inevitably leading to deflection of the follower arm. The control arm can absorb the vibrations and be deflected. The follower arm follows the deflection of the control arm, so that the vibrations do not necessarily result in deflection of the follower arm relative to the control arm. Consequently, the normal force which the follower arm exerts on the counter-contact surface can be comparatively small. Damage to the contact point of the follower arm and/or of the counter-contact point on the counter-contact surface can thereby be prevented or minimised. This deflection which the follower arm undergoes due to the deflection-following coupling to the control arm does not have to correspond to the deflection of the control arm in such case; it may also be smaller. Advantageous developments and configurations, which can be combined with each other in any way whatsoever, are described below.

The contact point of a contact arm can be fixed to a distal end of the contact arm, for example to its free end. Compared with a fairly central arrangement, this configuration represents a simple solution which greatly simplifies the calculation of a geometry and/or the normal force, since a possibly freely oscillating element on the other side of the contact point does not have to be taken into account.

The follower arm can be coupled to the control arm by a connection. In particular, this connection may be a mechanical connection, especially a direct mechanical connection. For example, a rigid connection, for example in the form of a material bridge, between the follower arm and control arm can assume the coupling function. A mechanical connection of this type means that reliable coupling can be achieved.

According to the invention, it is sufficient if the deflection of the follower arm follows the deflection of the control arm. Additionally, deflection of the follower arm can also result in deflection of the control arm. Both contact arms can follow the deflection of the respective other arm. The follower arm and the control arm can therefore be coupled to each other in deflection-transmitting manner.

Deflection of the control arm may lead in particular to deflection of the follower arm which is greater than the deflection of the control arm if the latter follows a deflection of the follower arm. This is for example possible if the follower arm is longer than the control arm.

The contact arms may have a base at their proximal ends. At this base, they can be fixed to further elements of the contact assembly.

The at least one control arm may be connected to the at least one follower arm via a common base. A common base of this type represents a mechanical coupling which is very simple to realise. Preferably the common base is located at a proximal end of the control arm which lies opposite the distal end. With this configuration, the oscillation characteristics of the two contact arms can be considered almost in isolation from each other. Merely the deflection-following coupling of the follower arm to the control arm has to be taken into account. Alternatively, the common base may be located at a proximal end of the follower arm and a distal end of the control arm. The follower arm can therefore stand away from the distal end of the control arm, for example in the direction of the longitudinal extent of the control arm or transversely thereto. A configuration of this type may be fixed to further elements of the contact assembly, in particular to fastening elements, only via the control arm. The follower arm may be connected only to the control arm. With such a configuration, the follower arm can be connected rigidly to the control arm, which simplifies calculation of the geometry. In the case of rigid coupling of the follower arm to the control arm, the control arm can absorb the deflections due to the vibrations, and the follower arm can exert an almost constant force, in particular an almost constant normal force, on the counter-contact surface.

The at least one control arm and/or the at least one follower arm may at least partially form the common base. The common base may be part of the control arm and/or of the follower arm. In another configuration, the common base may be a separate part, to which the control arm and the follower arm are fixed.

The at least one control arm and the at least one follower arm may be coupled to each other in deflection-transmitting manner via at least one elastically deflectable base. A mechanical coupling of this type via the elastically deflectable base represents a solution which is simple to realise in manufacturing terms. The base in such case may be located at the proximal ends of the contact arms. Deflection of the control arm and/or of the follower arm may result in particular in deflection of the base. The deflection of the base may in turn be transmitted to the other contact arm.

The control arm and the follower arm may be of one piece with each other. For example, they may be connected together via a material-formed join. Advantageously, the follower arm and the control arm consist of a single part. For example, both parts may be manufactured from a single semi-finished product. In an advantageous configuration, both are formed by punching out of a single metal sheet.

The at least one control arm and/or the at least one follower arm may be of one piece with other elements of the contact assembly. For example, the control arm and/or the follower arm may be of one piece with a fastening element. Especially, the control arm and/or the follower arm may be of one piece with the entire contact assembly. In another configuration, the control arm and/or the follower arm may be of one piece with a common base and/or an elastically deflectable base. A one-piece configuration ensures permanent and reliable transmission of the deflections. Further, a one-piece configuration is advantageous in manufacturing terms, for example because only a single forming step is necessary.

In order to guarantee reliable mechanical contacting, the at least one control arm, upon a predetermined deflection, can exert a greater normal force at its distal end than the at least one follower arm at its distal end. Such a configuration can further ensure that the control arm in the event of stronger vibrations produces an electrical contact if the follower arm can no longer guarantee this due to its lower normal force. Also penetration of contamination or oxide layers can be ensured by a greater normal force on the control arm. In order to ensure this at different intensities of vibrations, the at least one control arm for all deflections can exert a greater force at its distal end than the at least one follower arm at its distal end. A deflection in such case may be caused by a translatory or a rotary movement of the counter-contact surface. Measurement of the force preferably takes place at the contact point. It is the product of the spring constants times the distance between the contact point and a centre of rotation.

In order to keep the variation of the normal force which acts on the contact point of the follower arm as low as possible, upon simultaneous deflection of the same magnitude of the at least one control arm and of the at least one follower arm a normal force which acts counter to a direction of deflection and/or a normal direction in the control arm can increase more greatly than in the at least one follower arm. The at least one control arm and/or the at least one follower arm may in particular have a non-linear force/deflection characteristic. An incremental increase in force per incremental increase in deflection may be greater in the control arm than in the follower arm. The increase in force per deflection distance may be greater in the control arm than in the follower arm. The greater increase or the greater rise may be present over the entire deflection. It is however sufficient if this is present only in a partial range of the deflection. In particular, this partial range may be the range which occurs at normal vibration stress.

In a structurally simple embodiment, the at least one control arm is stiffer than the at least one follower arm.

Alternatively, the at least one control arm may be less stiff than the at least one follower arm. In order to achieve a deflection-following coupling of the follower arm to the control arm, in this case the control arm may be longer than the follower arm. Further, the type and position of the coupling may be selected such that the follower arm follows the control arm, even if the control arm is more elastic than the follower arm.

In order to ensure that the electrical contact between the follower arm and the counter- contact surface remains the same, upon simultaneous deflection of the same magnitude of the at least one control arm and the at least one follower arm a normal force which acts counter to a direction of deflection and/or a normal direction in the at least one follower arm may remain the same. Often it is sufficient if this is the case only in a partial range of the deflection. For example, this may be the range in which normal vibration stresses occur. Advantageously, the normal force however remains constant over the entire deflection distance. The control arm can absorb the vibrations and the forces associated therewith, so that the normal force of the follower arm can remain the same. In particular, the normal force of the follower arm may retain the value which it has in the rest position of the follower arm.

Further, it may be sufficient according to the invention that upon simultaneous deflection of the same magnitude of the at least one control arm and the at least one follower arm a normal force which acts counter to the direction of deflection in the at least one follower arm increases considerably less greatly than would be the case for deflection of the follower arm alone without deflection of the control arm. For example, upon simultaneous deflection the value of the normal force of the follower arm may be less than 50%, in particular less than 20%, especially less than 10%, of the normal force of the follower arm upon deflection of the follower arm alone.

In order to exploit the lever action to the maximum, the at least one control arm may be longer than the at least one follower arm. The distance of the distal end, in particular of the contact point of the contact arm from a centre of deflection, for example a centre of rotation, and/or from the base may be greater for the control arm than for the follower arm. If a force of the same magnitude acts on the control arm and the follower arm, the control arm in the region of the coupling between the control arm and follower arm exerts a greater force than the follower arm. This can guarantee that the follower arm follows the control arm more strongly than vice versa.

In order to save space, the control arm and the follower arm may run at least partially next to one another.

In an advantageous configuration, the control arm is longer than the follower arm, and runs in a partial region next to the follower arm. At the end of the follower arm, the control arm encompasses the follower arm, so that the contact point of the control arm in the direction of the longitudinal extent of the follower arm lies on the longitudinal axis of the follower arm. This makes the design even more compact.

In addition to the control arm and/or the follower arm, the contact assembly may have further elements. For example, fastening elements may be present. The at least one control arm and/or the at least one follower arm may be fastened to such further elements at an angle. For example, the at least one control arm and/or the at least one follower arm may be fixed to fastening elements at an angle of approximately 6° - 10°. In in-house tests, an angle of approximately 8° proved particularly advantageous. If further a base is present, this may be fixed to the fastening elements and/or contact arms at an angle. This may in particular result in the control arm and/or the follower arm in the rest state being pre- stressed when contact with a counter-contact surface is produced. The pre-stress may assume a different value in the control arm than in the follower arm; in particular, it may be greater in the control arm than in the follower arm.

In order to ensure a defined contact position and a constant contact resistance, the at least one control arm and/or the at least one follower arm may have a contact surface at its distal end. This may be in particular a rounded-off contact surface. The contact surface may be rounded-off in a longitudinal extent of the contact arm and/or transversely to a longitudinal extent of the contact arm. In a particularly advantageous configuration, the contact surface has a spherical-segment-like configuration. This guarantees particularly gentle contacting, in particular upon relative movements between the contact surface and the counter-contact surface, without scratching the counter-contact surface.

In order to contact the counter-contact surface at a particularly beneficial angle, for example for almost parallel contacting, the control arm and/or the follower arm may have a bend which angles a front part at the distal end of the contact arm in the direction of deflection from a rear part at the proximal end of the contact arm. Angling of a rear part can be compensated thereby.

In one particularly advantageous embodiment, only the follower arm, but not the control arm, has a bend which angles a front part at the distal end from a rear part at the proximal end. This means that the control arm is more greatly pre-stressed than the follower arm upon contact with the counter-contact surface. Further, a movement of the counter-contact surface in this configuration may result in a weaker deflection of the follower arm compared with the control arm.

For a well-defined deflection of the control arm and/or of the follower arm, it is advantageous if the control arm and/or the follower arm is flat. The control arm and/or the follower arm may be thinner in the direction of deflection than in a transverse direction which is perpendicular to the direction of deflection and perpendicular to the longitudinal extent of the contact arm. The control arm and/or the follower arm may be configured in the manner of tongues. The contact assembly may be a punched part. For example, the contact assembly may consist of a single sheet-metal part. This may for example be punched out of a larger sheet- metal part.

Alternatively, the control arm and/or the follower arm may in each case be individual parts which are fixed to one another via a crimp connection. Further, the control arm, the follower arm and/or a base may be fixed to further elements, for example to fastening elements, via a crimp connection.

A contact assembly according to the invention may have more than one control arm. Further, a contact assembly according to the invention may have more than one follower arm. For example, two follower arms may be coupled to one control arm. A single follower arm may also have two control arms.

In order to contact a metal sheet from both sides, a contact assembly according to the invention may also have two individual contact assemblies, which each consist of a control arm and an associated follower arm. The two contact assemblies may be deflectable in opposite directions. A metal sheet can thereby be clamped between the two individual contact assemblies. In the rest positions, the contact points of the two contact assemblies may touch one another if no metal sheet is arranged between them.

A contact arrangement according to the invention comprises a contact assembly according to the invention and a counter-contact surface which is electrically contacted by the contact points of the contact assembly. In particular, a normal force may be exerted on the counter-contact surface at the contact points.

The counter-contact surface may elastically deflect and/or pre-stress at least one contact arm in the rest state, i.e. without vibrations. This guarantees reliable contacting.

In one advantageous embodiment, the control arm exerts a greater normal force on the counter-contact surface than the follower arm. The control arm thus ensures above all mechanical contacting, whereas the follower arm guarantees electrical contacting which changes less considerably over time than with the control arm.

The greatest force of the control arm may be caused by the mechanical properties of the control arm. Alternatively and/or additionally, the control arm may be more greatly pre- deflected and pre-stressed by the counter-contact surface than the follower arm. For example, the contact assembly may be configured such that the control arm touches the counter-contact surface earlier than the follower arm upon the production of the contact. The control arm may therefore already be deflected and pre-stressed before the follower arm touches the counter-contact surface.

The invention will be explained below with reference to different embodiments. The developments described therein are each advantageous per se and may be combined with one another in any manner whatsoever.

In the figures:

Fig. 1 shows a diagrammatic perspective view of a contact assembly according to the invention;

Fig. 2 shows a further diagrammatic perspective view of the contact assembly according to the invention of Fig. 1 from an opposite position;

Fig. 3 shows a diagrammatic perspective view of a contact arrangement according to the invention comprising the contact assembly according to the invention of Figs. 1 and 2 and a counter-contact surface;

Fig. 4 shows a diagrammatic perspective view of the contact arrangement according to the invention of Fig. 3 from a lateral direction;

Fig. 5 shows a diagrammatic perspective view of a contact arrangement according to the invention comprising a plurality of contact assemblies according to the invention and counter-contact surfaces.

Fig. 1 shows a contact assembly 1 according to the invention. The contact assembly 1 has two contact arms 2. One contact arm 2 forms a control arm 3, and the other contact arm 2 forms a follower arm 4. The follower arm 4 is coupled to the control arm 3 in deflection- following manner. Deflection of the control arm 3 of necessity results in deflection of the follower arm 4.

The coupling between the follower arm 4 and the control arm 3 is configured to be mechanical. The follower arm 4 is connected to the control arm 3 at a common base 5. The common base 5 is further an elastically deflectable base 6. If the control arm 3 is deflected in the normal direction N, this results in a deflection of the common base 5. The common base 5 transmits the deflection to the follower arm 4, so that the latter follows the control arm 3 in its deflection. The follower arm 4 in such case does not necessarily have to be deflected itself by contact with a counter-contact surface. The common base 5 is located at a proximal end P of the control arm 3 and at a proximal end of the follower arm 4.

The common base 5 is in turn fixed to a fastening element 7 of the contact assembly 1. The common base 5 can be elastically deflected relative to the fastening elements 7 of the contact assembly 1, at least at its distal end D, and therefore represents an elastically deflectable base 6.

The control arm 3 and the follower arm 4 in this configuration are coupled to one another in deflection-transmitting manner. Consequently, not only does deflection of the control arm 3 result in deflection of the follower arm 4, but also deflection of the follower arm 4 at least partially results in deflection of the control arm 3.

The control arm 3, the follower arm 4, the common base 5 and the fastening element 7 in this configuration are of one piece with each other. They consist of a single piece of metal sheet. They were formed by punching from a larger piece of metal sheet. In a further method step, the common base 5 together with the contact arms 2 was slightly bent at the connection point 51. In order to keep the front part 30 of the control arm 3 parallel to a counter-contact surface, the front part 30 of the contact arm 2 was bent back somewhat relative to a rear part 31 of the control arm 3 counter to the first bend at a further bending point 53. Analogously, a front part 40 of the follower arm 4 was bent back relative to a rear part 41 of the follower arm 4 at a bending point 54. In an advantageous embodiment, not shown, only the follower arm 4 has a bending point 54, whereas the control arm 3 is formed straight.

Alternatively to the one-piece embodiment shown here, individual elements of the contact assembly 1 may be connected together and/or fixed to one another via crimp connections. For example, the common base 5 may be fixed to a fastening element 7 via a crimp connection.

The control arm 3 runs at least partially next to the follower arm 4. This means that the space requirement in a transverse direction Q running transversely to a longitudinal direction L of the contact arms 2 and transversely to the normal direction N is minimised.

The control arm 3 is longer in the longitudinal direction L than the follower arm 4. Due to the greater lever action, the control arm 3 exerts a greater force on the common base 5 than the follower arm 4 would for a deflection of the same magnitude in the normal direction N. The follower arm 4 therefore follows the control arm 3 more strongly than vice versa.

In order to minimise further the space required, the control arm 3 encompasses the follower arm 4 at the distal end D. The contact point 8B of the control arm 3 lies on an extension of the follower arm 4 in the longitudinal direction L. The contact point 8A of the follower arm 4 therefore lies between the contact point 8A of the control arm 3 and the common base 5.

Both contact arms 2 are flat. Their thickness measured in the normal direction N is less than their breadth measured in the transverse direction Q, and much less than their length measured in the longitudinal direction L. A force which is exerted on one of the contact points 8 therefore results in a deflection which runs mainly in the normal direction N. The special geometry of the control arm 3, the follower arm 4, the common base 5 and the fastening element 7 which is shown here, upon simultaneous deflection of the contact point 8A of the control arm and the contact point 8B of the follower arm 4, results in a normal force F4, which runs counter to the normal direction N and is generated by the follower arm 4 at the contact point 8B, being of almost the same amount over a wide range. Upon such a simultaneous deflection of the same magnitude, the control arm 3 for the most part absorbs the forces acting on the contact assembly 1. The normal force F3 generated by the contact arm 3, which is directed counter to the normal direction N and is exerted by the control arm 3 at the contact point 8A, therefore increases more greatly with increasing deflection than the normal force F4 of the follower arm 4. In Fig. 2, the contact assembly shown in Fig. 1 is illustrated from a different perspective. The contact points 8 of the contact arms 2 can be clearly recognised. These contact points 8 are formed as contact surfaces 9. The contact surface 8A of the control arm 3, just like the contact surface 9B of the follower arm 4, is rounded off in the longitudinal direction L and in the transverse direction Q. The contact surfaces 9 therefore have the shape of a spherical segment. Owing to this configuration, they can be moved back and forth on a counter- contact surface easily and without causing destruction. In such case, the size of the actual contacting area between the contact surface 9 and the counter-contact surface upon these movements is approximately identical.

A transitional region 52 between the common base 5 and the fastening element 7 is embodied as a rounded-off transitional region 52'. A configuration of this type is advantageous in manufacturing terms, and in operation does not offer any starting points for cracking by means the operation of the contact assembly 1 might be impaired. Fig. 3 shows a contact arrangement 10 according to the invention. The contact arrangement 10 consists of the contact assembly 1 and a counter-contact surface 11. The two contact arms 2 press in a connecting direction C onto the counter-contact surface 11, and thus produce an electrical contact between the contact assembly 1 and the counter-contact surface 11. If relative movements caused by vibrations occur between the contact assembly 1 and the counter-contact surface 11, these can be absorbed by the elastically deflectable contact arms 2. The control arm 3 in such case absorbs the major part of the forces occurring due to the deflection of the contact arms 2. The control arm 3 ensures mechanical contact. Additionally, electrical contacting is possible via the control arm 3. In particular, the stronger normal force F3 which the control arm 3 exerts on the counter-element 11 at the contact point 8A may result in oxide layers or impurities being penetrated and reliable contact being possible.

In this special configuration of the contact assembly 1, the normal force F4 which the follower arm 4 exerts on the counter-contact surface 11 at the contact point 8B of the follower arm 4 is virtually identical over a wide deflection range. This prevents the connection between the contact point 8B of the follower arm 4 and the counter-contact surface 11 from changing, in particular becoming impaired, over time. The normal force F4 is adjusted such that abrasion is minimised, while an electrical contact between the contact surface 8B and the counter-contact surface 11 is ensured .

Due to the spherical-segment-like configuration of the contact surfaces 8A, 8B, also relative movements between the contact assembly 1 and the counter-contact surface 11, in a first transverse direction Tl which is perpendicular to the connecting direction C and in a second transverse direction T2 which is perpendicular to the connecting direction C and perpendicular to the first transverse direction Tl, result in only minimal wear, since no sharp edges are present in the contacting region.

The contact arrangement 10 is illustrated in a rest state R without vibration. In this rest state R, the counter-contact surface 11 deflects the control arm 3. The control arm 3 is therefore already pre-stressed in this rest state R. The counter-contact surface 11 also deflects the follower arm 4. It too is already pre-stressed in this rest position R.

The control arm 3 exerts a greater force on the counter-contact surface 11 than the follower arm 4. The normal force F3 of the control arm 3 in this rest state is greater than the normal force F4 which the follower arm 4 exerts on the counter-contact surface 11. If the two contact arms 2 are deflected by vibrations in a normal direction N which in this case is directed counter to the connecting direction C, the control arm 3 reacts more strongly than the follower arm 4. Per unit of deflection of the counter-contact surface 11, its increase in force is greater than the increase in force of the follower arm 4. Fig. 4 shows the contact arrangement of Fig. 3 in a lateral view. The common base 5 is angled by an angle a relative to the fastening element 7 of the contact assembly 1. The direction of the common base 5 therefore encloses an angle a with the direction L7 of the fastening element 7. In this example, the angle a is approximately 8°. For this, the common base 5 is bent relative to the fastening element 7 in the direction of the counter-contact surface 11 at a connection point 51 of the fastening element 7 and the common base 5.

In order to guarantee contacting of the contact arms 2 at the contact points 8 which is as parallel as possible, the contact arms 8 are bent back relative to the common base 5. The control arm 3 is divided into a front part 30 and a rear part 31 at a bending point 53. The front part 30 has the same direction as the fastening element 7, i.e. the direction of the front section 30 of the control arm 3 is parallel to the direction L7 of the fastening element 7. The direction L3 of the control arm 3 consequently encloses an angle a with the direction L5 of the common base 5.

The follower arm 4 has a front section 40 which is angled by an angle a relative to a rear section 41. This is realised via a bend at a bending point 54 of the follower arm. The direction of the front section 40 of the follower arm 4, at least in the position shown here, is parallel to the direction 30 of the front section of the control arm 3. The directions shown here do however change upon deflection of the contact arms 2. Consequently, the orientations of the directions relative to one another may differ from each other in different positions. In a departure from the embodiment shown here, the control arm 3 may be embodied without a bend 53. This may result in the control arm 3 touching the counter-contact surface 11 earlier than the follower arm 4. This means that the control arm 3 can build up a greater pre-stress than the follower arm 4. In this embodiment, therefore, the front part 30 does not run parallel to the fastening element 7 or to the direction L7. The counter-contact surface 11 in the example shown here is contacted from a single side, the front side 60. In order to contact a metal-sheet-like counter-contact surface 11 on both sides, in addition to the contact assembly 1 shown here a further contact assembly which contacts the counter-contact surface 11 from the rear side 61 might be present. The two contact assemblies could clamp the counter-contact surface. In particular, the contact assemblies 1 could be arranged such that the contact points 8 mutually touch each other without an introduced counter-contact surface 11.

Fig. 5 shows a contact arrangement 10 according to the invention in the form of a sleeve- like connection 12. The contact arrangement 10 shown here has a plurality of contact assemblies 1 according to the invention which contact corresponding counter-contact surfaces 11 at several points.

A sleeve-type plug 20 is electrically connected to a sleeve-type bush 21 by the contact assembly 1. Upon relative movements between the sleeve-type plug 20 and the sleeve-type bush 21, which may be caused e.g . by vibrations, the contact assembly 1 according to the invention ensures that the electrical contact is present. In this case, the normal force F4 of the follower arms 4 is constant over a wider range owing to the configuration according to the invention. This, even when used over a relatively long period, guarantees that always identical contact with identical contact resistances can be produced, since the contact surfaces 8B of the follower arms 4 wear down the counter-contact surfaces 11 only slightly.

List of reference numerals

1 contact assembly

2 contact arm

3 control arm

4 follower arm

5 common base

6 elastically deflectable base

8 contact point

8A contact point of the control arm

8B contact point of the follower arm

9 contact surface

9A contact surface of the control arm

9B contact surface of the follower arm

10 contact arrangement

11 counter-contact surface

12 sleeve-like connection

20 sleeve-type plug

21 sleeve-type bush

30 front part of the control arm

31 rear part of the control arm

40 front part of the follower arm

41 rear part of the follower arm

51 connection point of fastening element to base

52 transitional region of base to fastening element

52' rounded-off transitional region of base to fastening element

53 bending point of the control arm

54 bending point of the follower arm

60 front side

61 rear side

D distal end

N normal direction

L longitudinal direction

P proximal end

Q transverse direction

R rest state

Tl first transverse direction

T2 second transverse direction

L3 direction of the front part of the control arm

L4 direction of the front part of the follower arm

L5 direction of the common base

L7 direction of the fastening element

F3 force at the contact point of the control arm

F4 force at the contact point of the follower arm

Claims

1. A contact assembly (1) for electrically contacting a counter-contact surface (11), comprising at least two elastically deflectable contact arms (2) with a contact point (8) for contacting the counter-contact surface (11), characterised in that at least one contact arm (2) forms a control arm (3) and at least one contact arm (2) forms a follower arm (4), the follower arm (4) being coupled in deflection-following manner to the control arm (3) and deflection of the control arm (3) inevitably leading to deflection of the follower arm (4).

2. A contact assembly (1) according to Claim 1, characterised in that the at least one control arm (3) is connected to the at least one follower arm (4) via a common base

(5).

3. A contact assembly (1) according to one of Claims 1 or 2, characterised in that the at least one control arm (3) and the at least one follower arm (4) are coupled to each other in deflection-transmitting manner via at least one elastically deflectable base (6).

4. A contact assembly (1) according to one of Claims 1 to 3, characterised in that the at least one control arm (3) and the at least one follower arm (4) are of one piece with each other.

5. A contact assembly (1) according to one of Claims 1 to 4, characterised in that the at least one control arm (3), upon at least one predetermined deflection, exerts a greater force at a distal end (D) than the at least one follower arm (4) at a distal end (D).

6. A contact assembly (1) according to one of Claims 1 to 5, characterised in that the at least one control arm (3) is longer than the at least one follower arm (4).

7. A contact assembly (1) according to one of Claims 1 to 6, characterised in that the at least one control arm (3) and the at least one follower arm (4) run at least partially next to one another.

8. A contact assembly (1) according to one of Claims 1 to 7, characterised in that upon simultaneous deflection of the same magnitude of the at least one control arm (3) and of the at least one follower arm (4) a normal force (F3) which acts counter to a normal direction (N) in the control arm (3) increases more greatly than a normal force (F4) of the at least one follower arm (4) which acts counter to the normal direction (N).

9. A contact assembly (1) according to one of Claims 1 to 8, characterised in that the at least one follower arm (4) is stiffer than the at least one control arm (3).

10. A contact assembly (1) according to one of Claims 1 to 9, characterised in that upon simultaneous deflection of the same magnitude of the at least one control arm (3) and the at least one follower arm (4) a normal force (F4) which acts counter to a normal direction (N) in the at least one follower arm (4) remains the same.

11. A contact assembly (1) according to one of Claims 1 to 10, characterised in that upon simultaneous deflection of the same magnitude of the at least one control arm (3) and the at least one follower arm (4) a normal force (F4) which acts counter to a normal direction (N) in the at least one follower arm (4) is less than 50%, preferably less than 20%, in particular less than 10%, of the normal force (F4) in the at least one follower arm (4) upon deflection of the follower arm (4) alone.

12. A contact assembly (1) according to one of Claims 1 to 11, characterised in that the at least one control arm (3) and/or the at least one follower arm (4) has a contact surface (9) at its distal end (D) which is at least partially round in the direction (L) of the longitudinal extent and/or in a direction (Q) transversely to the longitudinal extent of the contact arm (2).

13. A contact arrangement (10), comprising a contact assembly (1) according to one of Claims 1 to 12 and a counter-contact surface (11) which is electrically contacted by the contact points (8) of the contact arms (2).

14. A contact arrangement (10) according to Claim 13, characterised in that the counter-contact surface (11) elastically deflects at least one contact arm (2) in a rest state (R).

15. A contact arrangement (10) according to one of Claims 13 or 14, characterised in that a normal force (F3) which the control arm (3) exerts on the counter-contact surface (11) is greater than a normal force (F4) which the follower arm (4) exerts on the counter-contact surface (11).