CN114041197B

CN114041197B - Electrical contact system for a switching device

Info

Publication number: CN114041197B
Application number: CN202080035942.7A
Authority: CN
Inventors: ***·赫尔曼; 艾瑞克·赫佐格; 尼尔斯·戈勒
Original assignee: Johnson Electric Guangdong Co Ltd
Current assignee: Johnson Electric Guangdong Co Ltd
Priority date: 2019-07-02
Filing date: 2020-07-02
Publication date: 2023-12-12
Anticipated expiration: 2040-07-02
Also published as: DE102019117804B4; CN114041197A; EP3981019A1; WO2021001465A1; DE102019117804A1

Abstract

The invention relates to an electrical contact system (2) for a switching device (1), comprising at least one pair of contacts (3), said contacts (3) having a fixed contact (4) and a movable contact (5). The movable contact (5) is connected to a slider (15). A planar contact carrier (7) extends in its longitudinal section and is connected at a first end (11) to a second busbar (13). A second end (12) of the contact carrier (7) is connected to the slider (15). A spring element (18) has a first spring arm (22) and a second spring arm (23) and a pressure part (24) arranged between them in the region of the movable contact (5). The first spring arm (22) is connected to the second busbar (13) at the first end (11). The second spring arm (23) is also shown connected to the slider (15) at its free end (21).

Description

Electrical contact system for a switching device

Technical Field

The invention relates to an electrical contact system for a switching device, wherein the switching device for the invention may comprise a relay, a switch, a contactor and a circuit breaker.

Background

Switching devices such as relays, switches, contactors and circuit breakers should have the following characteristics: due to the low resistance between the connection terminals, low losses, a high efficiency can be achieved, as well as safety of the device during operation, in particular in terms of heating and fire protection, and long service life, which means that as many switching operations as possible are carried out under load; and protection measures to prevent the contacts from sticking to each other due to high short-circuit currents, for example, in the event of an electrical fault.

In conventional switching devices, the spring element ensures that the movable contact lifts off the fixed contact quickly when the contact is released, thereby reducing wear of the contact.

In particular in relays, such spring elements are usually made of steel and are riveted to the movable contact. The disadvantage associated with these steel elements riveted to the movable contact is that, due to the high load and low flexibility, this in turn only contributes to a minimum tolerance compensation.

Spring elements or mechanical coupling elements (hereinafter referred to as sliders) made of steel are also known which are connected to the magnetic actuators of the switching devices. The magnetic actuator generates and then the slider transmits the force required to open or close the contacts. A spring may be used here to release two or more contacts simultaneously. However, a disadvantage of connecting the spring element to the actuator or slider is that a device constructed in this way is hardly suitable for delaying the opening or closing of at least two pairs of contacts. This delayed opening or closing of the contacts is also known as a lead-lag switching characteristic.

Another form known in the art comprises a spring element integrated into the current path of the contact carrier for the movable contact. However, this will result in a larger mechanical load than the above-described direct connection of the spring element to the movable contact. In addition, it has the disadvantage that the spring heats up, which can lead to deformation of the slider and thus to a shortened service life of the contact system. Furthermore, since the contact carrier is deformed during the short circuit due to the following conditions, the rolling-down movement of the contact is restricted. In the case of a spring element connected to the movable contact, for example by riveting, the high stiffness results in a reduced flexibility of the spring element and thus limits the rolling movement of the contact. In the case of springs integrated in the contact carrier of the movable contact, the rolling-off movement is limited due to the reduced flexibility of the current path of the contact carrier of the movable contact.

Disclosure of Invention

The basic object of the present invention is defined to provide a space-saving electrical contact system which can be produced economically, provides high performance, has a long service life and allows reliable absorption and transfer of short-circuit forces.

The object of the invention is solved by using an electrical contact system and a corresponding advantage is produced in a switching device equipped with an electrical contact system. Further embodiments are provided.

An electrical contact system constructed in accordance with the present invention is suitable for use in a switching device, such as a relay, having at least one pair of contacts having a fixed contact, the contacts being connected to a first bus bar having a fixed position relative to a housing of the switching device, and a contact movable relative to the fixed contact, wherein the contacts are connected to and movable by a slider such that the pair of contacts are movable in an open and closed manner between; a planar contact carrier to which the movable contact is connected, wherein the contact carrier extends in its longitudinal section along its longitudinal axis from a first end to a second end, wherein the first end is connected to a second busbar, the position of which is fixed relative to the housing of the switching device, wherein the second end of the contact carrier is connected to the slider; one spring element has a first spring arm and a second spring arm and a pressure part arranged between them in the region of the movable contact, wherein the first spring arm is connected to the second busbar at a first end of the contact carrier and wherein the second spring arm is also connected to the slider at its free end in such a way that the spring element exerts a contact force on the movable contact via the pressure part.

The spring element has a lower electrical conductivity than copper or has an electrically insulating coating, for example an insulating varnish. An electrically insulating spring element may be useful if a large part of the current flows through the spring element, as this allows to reduce the current in the contact carrier designed as a layered structure. This reduces the repulsive force in the layered contact carrier in the short circuit test, called "blow-off force".

Furthermore, the spring element is connected to the second busbar and has at least one spring arm with a first spring arm portion and a second spring arm portion, wherein the first spring arm portion extends from the connection section upwards to a position with at least one pressure portion, from which position the second spring arm portion extends to a free end of the spring arm. This achieves a defined contact force even after overheating of the contact carrier and ensures reliable maintenance of the relay function.

If the planar contact carrier is substantially straight along its longitudinal axis from the first end to the second end in its longitudinal section, tolerance problems can be controlled in a technically simple manner.

According to the invention, the at least one pressure part is positioned such that a direct or indirect force-locking connection between the pressure part and the movable contact piece can be produced by a preload of the spring element, thereby allowing a force to be exerted on the pair of contacts.

When the pair of contacts are electrically disconnected, the spring element remains preloaded and exerts a contact force on the contacts via the pressure portion. Advantageously, the contact force is effective immediately upon closing of the contacts, compressing the contacts and minimizing contact bounce.

Alternatively, the contact carrier of the movable contact may be positioned in such a way that it increases the contact force and further reduces bouncing and contact resistance when the contact is closed.

In order to be able to benefit from attractive or repulsive forces in the conductors through which the current flows, the contact carrier is ideally connected to the second busbar in such a way that it forms a V-shape with the second busbar in longitudinal section, in other words along the longitudinal axis.

The conceptual design according to the invention focuses on the use of a spring element with low conductivity and a contact carrier of the movable contact to be connected to the same busbar. Such spring elements combine various beneficial mechanisms of action with each other. The spring element is preferably designed in the form of a sheet or strip. In one embodiment, the spring element is a leaf spring.

The spring element may be made of paramagnetic or alternatively diamagnetic material. The spring element should preferably be made of a material having paramagnetic properties. Particularly preferred materials herein are stainless steel or stainless steel alloys. The material of the spring element must necessarily be less conductive than the material of the stationary busbar and the contact carrier in order to allow as little current as possible to flow through the spring element. The conductivity difference between steel and copper is a factor between 6 and 7. For example, if the fixed position busbar and the contact carrier are made of aluminum instead of copper, but the spring is still made of steel, the coefficient of conductivity between the two would be nearby, which is still sufficient. All materials having a lower electrical conductivity than steel provide a sufficiently low electrical conductivity for the spring element.

One advantageous effect is based on the force exerted on the contact pairs, which force is created by the preloading of the spring elements and presses the contacts together. This creates pressure parts at the interface between the contacts, so-called points a, where these pressure parts promote the current flow. The larger the pressure here, the larger the size (area) of the pressure portion available for current flow, and the lower the resistance at the pressure portion.

A further improvement over the prior art is achieved according to a preferred embodiment of the invention, by which the electrical contact system comprises a plurality of pairs of contacts, with contact forces being generated for each pair of separable contacts, respectively. The pairs of contacts may be connected in parallel here to keep the resistance low throughout the life even if one pair burns out. The plurality of movable contacts may be arranged on the contact carrier one after the other transversely to the longitudinal axis thereof or in the direction of the longitudinal axis or transversely to the longitudinal axis, but offset in the direction of the longitudinal axis. As mentioned above, the geometry of the burned-out pair of contacts may change, for example, due to burning itself, or particularly a bi-metallic contact rivet, due to delamination. The change in shape results in a change in the very important spring preload and thus also in a change in the contact force. To ensure that the unburnt contact pairs are not altered by the burnt contact pairs, a force is generated for each pair of contacts separately. This is achieved by advantageously designing the spring element as a leaf spring with separate spring arms for each pair of contacts. This results in low resistance, even when multiple pairs of contacts are used, one of which can burn out.

Another aspect of the invention relates to a switching device, such as a relay, comprising an electrical contact system according to the invention. The corresponding switching device further comprises an excitation coil and a solenoid, which is classified as an armature, which is operatively connected to a slider, which acts as a mechanical coupling element. The field coil can generate a force as a result of the magnetic field generated by the field coil, which force can then be applied to the electrical contact system via the armature and the mechanical coupling element, so that the electrical contact system can be switched via the field coil.

Another advantageous mechanism of action of the spring element is based on the creation of a force on the armature/solenoid, which force then supports this opening process, so that the contacts can be opened as quickly as possible. The greater the preload force of the spring element, the faster the opening speed of the contacts and the lower the severity of the contact burn-out (corrosion) due to the opening of the arc when the electrical load is opened. The less the contact burn-out, the more switching operations can be completed, thereby increasing the service life of the corresponding switching device.

The low spring constant of the spring element is particularly advantageous here. The spring constant generally represents the ratio of the forces acting on the spring to extend the spring. Due to the way the system works, a large part of the spring force will be applied to the solenoid after opening the contacts. Only a small part of the contact force is applied, as a result of the preload of the spring element (leaf spring) between the movable contact and the busbar connected to the movable contact carrier. The force component counteracts the opening movement and increases as the contacts open wider, because the spring portion is increasingly preloaded with the opening movement. A low spring constant means that increasing the preload distance only results in a minimal increase in force, and therefore the solenoid will only decelerate very slightly during the opening motion. This results in a faster opening movement of the contacts, thereby extending the service life of the device.

Another advantage is the high thermal stability based on the spring material. The contact system heats up during the switching operation. The spring material has corresponding thermal stability, and can ensure mechanical performance when the temperature is increased.

Another advantage is based on the fact that the spring material is either non-conductive or only low conductive and in the case of stainless steel, for example, has paramagnetic properties. The relation between the low conductivity or paramagnetism of the spring element and the beneficial effect, i.e. the prevention of contact welding, is explained in more detail below.

There are two key roles to prevent contact welding when a short circuit occurs. One of these effects focuses on the relative movement between the switching contacts as current flows through the contacts. Another effect is focused on increasing the contact force to increase the contact surface. First, this reduces the current density in the pressure portion between the contacts. Second, the shrinkage resistance (hall force) occurring between the contacts due to the current flow is compensated. The pinch resistance (hall force) always acts in the direction of the contact opening, which would result in the contact opening if a short-circuit fault were to occur without a corresponding reaction force. The force required to achieve these effects is generated by a magnetic field, which is generated by the short-circuit current itself. These effects should not be affected by the spring element. First, the low conductivity prevents high short-circuit currents from flowing through the spring element, so that no associated magnetic field is formed around the spring element. Secondly, the magnetic resistance exerted on the spring or surrounding components due to the magnetic field around the current path can be prevented by the paramagnetic properties of the spring element. This makes a valuable contribution to preventing the contacts from sticking together in a practical way, i.e. the relative movement between the switch contacts is not affected by the spring element.

Another advantageous mechanism of action is achieved by the spring element producing an orthogonal force on the pressure portion. Due to the spring preload, a force-locking connection is established between the switch electrical contact and the spring element. However, the force acts here without any torque component. The spring element rests with its pressure only on the rear side of the movable contact or on the part of the contact carrier adjacent to the movable contact and is not connected thereto. Thus, compressive forces, also referred to below as normal forces, can only be transferred orthogonally from the spring element to the contacts. The transmission of torque or significant lateral forces is not possible or is thus prevented. This results in the fact that the described relative movement transversely to the contact surface in the event of a short circuit is not impaired. Since the applied mode of action is not affected, the contacts can be more safely prevented from sticking together.

In a particularly preferred embodiment of the invention, the at least one movable contact has a projection, also called rivet collar, on its rear side, which projection extends through a corresponding mounting hole in the contact carrier. This allows the spring arms of the spring element to bear directly against the projections of the contact, the rivet ring, with pressure portions and exerting pressure. However, the at least one spring arm should preferably have a widened annular portion in the region of the pressure portion, which annular portion is arranged transversely to the longitudinal axis of the contact carrier, with a central recess which is positioned such that it rests on the contact carrier in the preloaded state and surrounds the projection of the rear side of the current movable contact. In said embodiment, the at least one spring arm preferably has two pressure portions in opposite positions of the widened annular portion.

Contacts without rivet rings may also be used. These can be soldered or welded to the contact carrier, so that no mounting holes are required. In this case, the spring arm of the spring element can rest directly against or press against the contact carrier on the rear side of the fixed position of the movable contact with only one pressure part.

In a preferred embodiment in terms of manufacture and function, the slider has a recess into which the second end of the contact carrier and the free end of the second spring arm of the spring element project.

Drawings

Fig. 1: a cross-sectional view of an electrical contact system with spring elements for use in a relay as a switching device;

fig. 2: a side view of a portion of the electrical contact system;

fig. 3: a spring element with two spring arms;

fig. 4: a perspective view of an electrical contact system having two contacts; and

fig. 5: a front view of a portion of an electrical contact system having two differently sized contacts.

Detailed Description

Fig. 1 shows a schematic cross-section of a relay 1 as an example of a switching device 1, in which an electrical contact system 2 with the features of the invention is applied. The electrical contact system 2 comprises at least one pair of contacts 3 formed by a pair of contacts 4, 5. Here, at least one pair of contacts comprises a fixed contact 4, which fixed contact 4 is connected to a first busbar 6 having a fixed position relative to a housing 33 of the switching device, and one movable contact 5 which is movable relative to the fixed contact 4 to perform the switching function, in such a way that the contacts of the contacts are positioned relative to each other in such a way that the movable contact 5 can be pressed against the fixed contact 4 by a contact force.

In addition to this, the electrical contact system 2 comprises a planar contact carrier 7 for at least one movable contact 5. The contact carrier 7 may have a spring characteristic and is therefore also generally referred to as a contact spring.

As shown in fig. 1, the planar contact carrier 7 is made of two current paths 8, 9 lying on top of each other and is essentially straight in its longitudinal section along its longitudinal axis from the first end 11 to the second end 12. The contact carrier 7 is connected with its first end 11 to a second busbar 13, the second busbar 13 having a fixed position, preferably riveted, with respect to the housing 33 of the switching device and forming a V-shape therewith in its longitudinal section. The at least one movable contact 5 is connected in the region of the second free end of the contact carrier 7. In the embodiment shown, the contact carrier 7 comprises a first, straight current path 8 and a second current path 9, wherein the second current path 9 is also constructed straight, except for a curved portion 10 protruding out of its plane and extending transversely to the longitudinal axis over the entire width of the contact carrier. The curved portion 10 is located near a first end 11 of the contact carrier 7, through which first end 11 the contact carrier 7 is connected to a second busbar 13.

The relay 1 also has a solenoid actuator for moving the contact carrier 7 to the respective relay position. The solenoid actuator has a magnetic coil, a permanent magnet and an armature 14, the armature 14 being pivotably held on the magnetic coil between two switching positions. The armature 14 is connected to a mechanical coupling element 15 in the form of a slider 15, so that the slider 15 can be raised and lowered by a rotational movement of the armature 14. The armature 14 can also be classified as a lifting magnet or a solenoid. The armature 14 is held by the slide 15 on its lower end section 16 from above and below in the direction of movement of the lifting movement of the slide 15. In the region of the free end 12 of the contact carrier 7, the upper end 17 of the slider 15 is located on its underside. The slider 15 connected to the armature 14 can then transmit the force generated by the magnetic field of the excitation coil in the relay 1 to the contact carrier 7 with the at least one connected movable contact 5, so that the contact between the fixed contact 4 and the movable contact 5 can be opened or closed by the excitation coil.

As a key feature of the invention, the electrical contact system 2 comprises a spring element 18 with low electrical conductivity, preferably made of stainless steel or stainless steel alloy. The spring element 18 is connected to the second busbar 13 and the contact carrier 7 for the movable contact 5 is also connected to the second busbar 13. The spring element 18 comprises a connecting portion 19, by means of which connecting portion 19 the spring element 18 is connected (preferably riveted) to the second busbar 13. Starting from the connecting portion 19, the spring element 18 has at least one spring arm 20 which extends from the connecting portion 19 all the way to a free end 21 of the spring element 18. At least one spring arm 20 may be split into two different spring arms 22, 23. The first spring arm 22 extends from the connecting portion 19 to the pressure portion 24, the spring element 18 resting only on the rear face of the movable contact 5 or on a portion of the contact carrier 7 close to the rear face of the movable contact 5, but not being connected to said movable contact 5 or contact carrier 7. From the pressure portion 24, the second spring arm portion 23 extends all the way to the free end 21 of the spring arm 20. The distance between the contact carrier 7 and the second spring arm 23 increases here starting from the pressure portion 24, at which pressure portion 24 the spring element 18 still rests on the movable contact 5 or the contact carrier 7 and continues as far as the free end 21 of the spring arm 20. This means that the two different spring arms 22,23 together form a V-shape.

Due to the preload of the spring element 18, which is schematically depicted as a continuous line by the second spring arm 23, there is a force locking connection 25 between the pressure portion 24 and the movable contact 5 and thus a force is applied to the contact 3 to press the contacts 4,5 together, as indicated by arrow 26. The force 26 applied to the contact 3 creates points of contact, the so-called points a, at the interface between the contacts 4,5, where these points of contact promote the flow of current. The larger the contact force here, the larger the size (area) of the contact point available for current flow, as indicated by arrow 27, and the lower the resistance at the contact point.

Another beneficial mechanism of action of the spring element 18 is based on the generation of a force on the armature/solenoid 14, wherein the force is represented by the arrow in fig. 1, which then supports the armature/solenoid 14 during opening. Said force also ensures that the contacts 3 can open as soon as possible. The greater the preload of the spring element 18, the faster the opening speed of the contact 3.

Due to the way the system works, after opening the contacts 3, a large part of the spring force is applied to the armature/solenoid 14. Although the spring arm 23 is always preloaded, when the electrical contact is opened, a mechanical contact is established between the second end 12 of the contact carrier and the slider 15. This alters the force flow. The preload force of the spring element 18 is completely absorbed in the slider 15 and is no longer dissipated by the armature 14. When the contacts are opened, the resultant force of the spring preload force 28 on the armature 14 is equal to zero. This is schematically shown in broken line form in fig. 1, which depicts a second spring arm portion 23'. Only a small part of the previously applied contact force is applied, as a result of the preload of the first spring arm 22, which acts as a spring element interposed between the movable contact 5 and the busbar 13 of the movable contact carrier 7. The component force counteracts the opening movement of the movable contact 5 and increases as the contact opens wider, because the spring arm 22 is increasingly preloaded with the opening movement. A low spring constant means that an increased preload distance only results in a minimal increase in force, so that the solenoid 14 slows down only very slightly in its opening movement. This results in a faster opening movement of the contacts 3 and thus a longer service life of the device.

When the contacts 3 of the pair are electrically disconnected, the spring element 18 remains preloaded and exerts a contact force 26 on the contacts via the pressure portion 24. Advantageously, said contact force is immediately effective when the contacts are closed, thereby compressing the contacts 3 and minimizing bouncing of the contacts 3.

Furthermore, a beneficial mechanism of action is achieved by the spring element 18 producing an orthogonal force on the pressure portion. Due to the spring preload, a force-locking connection is established between the contact 3 of the switch and the spring element 18. However, the force acts here without any torque component. The spring element 18 rests with its pressure 24 only on the rear side of the movable contact 5 or on a part of the contact carrier 7 adjacent to the rear side of the movable contact 5 and is not connected to said part. Thus, the compressive force can only be transmitted perpendicularly from the spring element 18 to the contact 3. The transmission of torque or significant lateral forces is not possible or is thus prevented. This means that the relative movement transverse to the contact surface is not affected when a short circuit occurs. This provides greater security against sticking of the contacts together.

In a preferred embodiment in terms of manufacture and function, the slider 15 has a recess 35 into which the second end 12 of the contact carrier 7 and the free end 21 of the second spring arm 23 of the spring element 18 project.

Fig. 2 shows a side view of a part of the electrical contact system 2. The part of the electrical contact system 2 comprises a planar contact carrier 7 for at least one movable contact 5. As shown in fig. 2, it comprises two current paths 8, 9 lying on top of each other and being essentially straight in its longitudinal section from a first end 11 to a second end 12 along its longitudinal axis. The contact carrier 7 is connected by its first end 11 to the second busbar 13, for example by means of a rivet joint, and forms a V-shape with the second busbar 13 in its longitudinal section. At least one movable contact 5 is connected in the region of the second free end 12 of the contact carrier 7. The contact carrier 7 comprises a first, straight current path 8 and a second current path 9, wherein the second current path 9 is also constructed straight, except for a curved portion 10 protruding outwards and extending transversely to the longitudinal axis, said curved portion 10 extending transversely to the longitudinal axis across the entire width of the contact carrier in the portion adjacent to the first end. In addition to the contact carrier 7, a spring element 18 is also connected to the second busbar 13. The spring element 18 comprises a connection portion 19, with which connection portion 19 the spring element 18 is fixed to the second busbar 13 via a riveted connection. Starting from the connecting portion 19, the spring element 18 has a spring arm 20 which extends from the connecting portion 19 all the way to a free end 21 of the spring element 18. The spring arm 20 may be split into two different spring arm portions 22,23'. The first spring arm 22 extends from the connecting portion 19 to the pressure portion 24, the spring element 18 resting only on the rear face of the movable contact 5 or on a portion of the contact carrier 7 close to the rear face of the movable contact 5, but not being connected to said movable contact 5 or contact carrier 7. From the pressure portion 24, the second spring arm portion 23' extends all the way to the free end 21 of the spring arm 20. The two spring arms 22,23' together form a V-shape.

Fig. 3 shows a spring element 18 constructed in accordance with an advantageous embodiment of the invention. The embodiments relate to a multi-contact system on which at least two movable contacts are arranged in the region of the second free end of the contact carrier and connected transversely to the longitudinal axis 34 of the contact carrier. Multiple pairs of contacts may then be switched in parallel. In this case, the spring element 18 can be constructed as a leaf spring with a connecting portion 19 and separate spring arms 20a,20b starting from the connecting portion 19. In the region of the pressure portions 24a,24b, a spring arm 20a;20b each have a widened portion 29a;29b, which are also referred to below as spring tongues 29a;29b. Each spring tongue 29a;29b have a central recess 30a;30b, making it substantially annular. Each spring arm 20a;20b are provided with annular spring tongues 29a;29b have two pressure portions 24a at opposite positions; 24b.

Fig. 4 shows a perspective view of an electrical contact system 2 with two pairs of contacts 3a,3b, wherein the spring element 18 shown in fig. 3 is used. In this case, a double-contact system is produced, wherein in the region of the second free end 12 of the contact carrier 7, the two movable contacts 5a,5b are arranged and connected transversely to the longitudinal axis of the contact carrier and each form a pair with a corresponding fixed contact 4a;4b, a contact 3a;3b. In the embodiment shown, the contact carrier 7 is divided into two parallel legs 31a, 31b at least at the end carrying the contacts. The grooves 30a,30b ensure that the pressure portions 24a,24b of the spring tongues 29a,29b do not directly rest against the movable contact element 5a;5b, but instead rest on adjacent portions of the contact carrier 7, as protrusions 32a formed on the back surfaces of the movable contacts 5a,5 b; 32b, the protrusions 32a;32b are located within the recesses 30a,30b, guided through the contact carrier 7 by corresponding holes in the contact carrier 7, and protruding from the contact carrier 7.

Fig. 5 shows a front view of a part of an electrical contact system 2 with two contacts of different dimensions. The differently sized movable contacts 5a,5b and their protrusions 32a,32b formed on the back surface also require differently sized spring tongues 29a,29b and differently sized grooves 30a,30b in the spring arms 20a,20 b.

The above description is merely of a preferred embodiment of the present invention, the protection scope of the present invention is not limited to the above-listed examples, and any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention disclosed in the present invention fall within the protection scope of the present invention.

REFERENCE SIGNS LIST

1. Relay and switching device

2. Electrical contact system

3. Contact, contact pair

3a contact, contact pair

3b contact, contact pair

4. Contact and fixed contact

4a contact, fixed contact

4b contact, fixed contact

5. Contact and movable contact

5a contact and movable contact

5b contact and movable contact

6. First bus bar

7. Contact carrier for a movable contact

8. Current path of contact carrier of movable contact

9. Current path of contact carrier of movable contact

10. Bending part

11. First end of contact carrier of movable contact

12. Second end of contact carrier

13. Second bus bar

14. Armature, solenoid valve

15. Mechanical coupling element, slider

16. Lower end section of slider

17. The upper end of the slide block

18. Spring element

19. Connecting portion of spring element

20. Spring arm

20a first spring arm (with two contact systems)

20b first spring arm (with two contact systems)

21. Free end of spring element

22. First spring arm portion

23. The second spring arm portion having a preloaded spring element

23' the second spring arm portion having a non-preloaded spring element

24. Pressure part

24a pressure part

24b pressure part

25. Force-locking connection

26. Force of spring element on contact, contact force

27. Electric current

28. Force of spring element acting on armature

29a first spring tongue, widened portion (with two contact systems)

29b second spring tongue, widened portion (with two contact systems)

30a first spring tongue groove

30b second spring tongue groove

31a first leg of the contact carrier (with two contact systems)

31b second leg of contact carrier (with two contact systems)

32a projection of the back of the first movable contact

32b projection of the rear face of the second movable contact

33. Shell body

34. Longitudinal axis of contact carrier

35. Grooves in the slider

Claims

1. An electrical contact system (2) for a switching device (1), the switching device (1) having a slider (15), the electrical contact system (2) comprising:

at least one pair of contacts (3) has one fixed contact (4), the fixed contact (4) being connected to a first busbar (6) which can have a fixed position relative to a housing (33) of the switching device, and one movable contact (5) which is movable relative to the fixed contact (4), wherein the movable contact (5) is connected to the slider (15) and the movable contact (5) is moved by the slider (15) such that the at least one pair of contacts (3) are opened and closed relative to each other;

-a planar contact carrier (7), to which contact carrier (7) the movable contact (5) is connected, wherein the contact carrier (7) extends in its longitudinal section from a first end (11) along its longitudinal axis (34) to a second end (12), wherein the first end (11) is connected to a second busbar (13), the position of the second busbar (13) being fixed relative to a housing (33) of the switching device, wherein the second end (12) of the contact carrier (7) is connected to the slider (15); and

a spring element (18) has a first spring arm (22) and a second spring arm (23) and a pressure part (24) arranged between them in the region of the movable contact (5);

the method is characterized in that: the first spring arm (22) is connected to the second busbar (13) at a first end (11) of the contact carrier (7), and the second spring arm (23) is connected to the slider (15) at its free end (21) in such a way that the spring element (18) exerts a contact force (26) on the movable contact (5) via the pressure portion (24), the spring element (18) being pressed against the movable contact (5) via the pressure portion (24) even when the pair of contacts (3) are electrically disconnected.

2. The electrical contact system (2) according to claim 1, wherein: the spring element (18) is curved in the region of the pressure part (24), in such a way that the spring element (18) has a V-shaped cross section in longitudinal section at least in the region of the pressure part (24).

3. The electrical contact system (2) according to claim 1, wherein: the spring element (18) has a lower electrical conductivity than copper or has an electrically insulating coating.

4. The electrical contact system (2) according to claim 1, wherein: the spring element (18) is made of paramagnetic or alternatively diamagnetic material.

5. The electrical contact system (2) according to claim 4, wherein: the spring element (18) is made of stainless steel or stainless steel alloy.

6. The electrical contact system (2) according to claim 1, wherein: the contact carrier (7) is connected to the second busbar (13) in such a way that it forms a V-shape or a U-shape together with the second busbar in a longitudinal section along the longitudinal axis.

7. The electrical contact system (2) according to claim 1, wherein: the electrical contact system (2) comprises a plurality of pairs of contacts (3 a,3 b), wherein a plurality of movable contacts (5 a,5 b) are arranged on the contact carrier (7) one after the other, transversely to the longitudinal axis thereof or in the direction of the longitudinal axis or transversely to the longitudinal axis, but offset in the direction of the longitudinal axis.

8. The electrical contact system (2) of claim 7, wherein: the spring element (8) is designed as a leaf spring.

9. The electrical contact system (2) of claim 7, wherein: the spring elements (8) are designed as individual spring arms (20 a,20 b) for each pair of contacts (3 a,3 b).

10. The electrical contact system (2) according to claim 9, wherein: the at least one movable contact (5 a,5 b) extends through a corresponding mounting hole in the contact carrier (7) and forms a protrusion (32 a,32 b) on its opposite side, and the at least one spring arm (20 a,20 b) comprises a widened annular portion (29 a,29 b) with a central recess (30 a,30 b) in the region of the pressure portion (24 a,24 b), which pressure portion (24 a,24 b) extends transversely to the longitudinal axis of the contact carrier (7) and is positioned in such a way that the protrusion (32 a,32 b) is located on the opposite side of the contact carrier (7) within the central recess (30 a,30 b) when preloaded.

11. The electrical contact system (2) of claim 10, wherein: the at least one spring arm (20 a,20 b) has two pressure portions (24 a,24 b) at opposite positions of the widened annular portions (29 a,29 b).

12. The electrical contact system (2) according to claim 1, wherein: the slider (15) has a recess (35), into which recess (35) the second end (12) of the contact carrier (7) and the free end (21) of the second spring arm (23) of the spring element (18) project.

13. A switching device (1) comprising an electrical contact system (2) according to any one of claims 1 to 12.

14. Switching device (1) according to claim 13, further comprising an excitation coil and an armature (14) operatively connected to the slider (15), said slider (15) acting as a mechanical coupling element (15), characterized in that: the field coil generates a force due to the magnetic field it generates, which is transmitted via the armature (14) and the mechanical coupling element to the electrical contact system (2), whereby the electrical contact system is switched by the field coil.

15. Switching device (1) according to claim 13, characterized in that: the switching device (1) is or comprises a relay.