Contact bridge subassemblies, contact bridge assemblies, and electrical switching devices

Abstract

This invention provides a contact bridge subassembly that can reduce electrical loss, heat generation, and wear in electrical switching devices. [Solution] The present invention relates to a contact bridge subassembly comprising a contact bridge (2) movable along the switching direction, wherein exactly three switching contacts (4) are arranged on the contact bridge (2), and the three switching contacts (4) define one contact plane. The present invention further discloses a contact bridge assembly (46) comprising such a contact bridge subassembly, and an electrical switching device (54) comprising at least one contact bridge subassembly and / or at least one contact bridge assembly (46).

Description

Technical Field

[0001] The present invention relates to a contact bridge subassembly for an electrical switching device such as a relay or a contactor, a contact bridge assembly comprising such a contact bridge subassembly, and an electrical switching device comprising at least one contact bridge subassembly and / or at least one contact bridge assembly.

Background Art

[0002] Switching devices such as relays and contactors are used to switch currents. To do this, a contact bridge is usually pressed against the fixed contacts of the relay or contactor to open and close the electrical circuit. When switching particularly high currents, it is important to minimize the transition resistance between the switching contacts and the fixed contacts of the contact bridge in order to reduce electrical losses, heat generation, and wear. In addition, the switching device needs to be highly durable, compactly constructed, and cost-effective in manufacturing.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Therefore, the present invention is based on the object of providing means that meet the above requirements.

Means for Solving the Problems

[0004] This object is solved by a contact bridge subassembly for an electrical switching device such as a relay or a contactor, comprising a contact bridge movable along a switching direction, with exactly three switching contacts arranged on the contact bridge, the three switching contacts defining a contact plane.

[0005] To establish good electrical contact between the contact bridge and fixed contacts of a switching device, all contacts of the contact bridge must reliably make contact with the fixed contacts that the switching contacts are adapted to make contact with. Failure to do so can lead to increased transition resistance or contact resistance, or even arc discharge, potentially damaging the switching device.

[0006] The contact bridge subassembly according to the present invention provides the contact bridge with exactly three switching contacts that define a plane, i.e., are not arranged in a straight line. This ensures that all three contacts make reliable contact with the fixed contacts they are contacting during operation. Like a tripod stool or tripod stand that stands securely even on uneven ground, the three switching contacts defining a contact plane make reliable contact with the fixed contacts even if the contacts are not precisely aligned. Such misalignment is not necessarily caused by manufacturing tolerances, but can also occur due to wear on some of the contacts. Therefore, the contact bridge subassembly according to the present invention maintains high functionality during operation even after wear.

[0007] The above invention can be further improved by adding one or more of the features described below, each of which is advantageous in itself and may be combined with any of the other features described herein, independently and / or in any desired manner.

[0008] To further improve electrical contact, at least one, preferably all, of the switching contacts may be at least partially rounded, curved, arc-shaped, concave, convex, or domed in shape. The apex of such a rounded portion of at least one switching contact may face away from the contact bridge. In a preferred embodiment, all switching contacts are fully rounded.

[0009] Switching contacts may be made of or composed of particularly resistant materials such as AgSnOx, which is intended to carry high currents, and / or particularly conductive materials such as fine-grained silver, which is suitable for reducing contact resistance. Naturally, the contacts may be made of different materials.

[0010] The switching contacts may be fixed to the contact bridge by, for example, welding, casting, or bonding. In one embodiment, the switching contacts may be formed monolithically with the contact bridge. Naturally, other mounting methods may be employed, and the switching contacts may be attached to the contact bridge using different mounting methods.

[0011] In order to conserve materials and thereby reduce manufacturing costs, according to another embodiment of the contact bridge subassembly, the contact bridge may have at least three legs, each of which is located on a different leg.

[0012] At least one, preferably all, of the switching contacts may be located at the free end of a leg. The free end may face away from the center of the contact bridge. The center may be located, for example, at the center of gravity of the contact bridge and / or at the intersection of the longitudinal axes of at least two, preferably three, of the legs on which the switching contacts are located.

[0013] The legs of the contact bridge may have different lengths. In particular, the legs may protrude from the center of the contact bridge by various distances. Naturally, embodiments in which all legs are of different lengths or of the same length are also possible.

[0014] The legs of the contact bridge may have different thicknesses and / or widths and / or cross-sections. The thickness of a leg may be measured along the switching direction, and the cross-section of a leg may be defined by a plane that intersects the longitudinal axis of each leg perpendicularly. The width of a leg may be measured along the switching direction and in a direction perpendicular to the longitudinal axis of each leg.

[0015] In a particularly robust embodiment of the contact bridge subassembly, at least two of the legs may be joined to each other at at least one joint. Preferably, all the legs of the contact bridge are joined to each other. The connection of at least two legs is preferably rigid, but may be flexible or movable.

[0016] In one embodiment, the joint may be configured as a node to which all the legs of the contact bridge are joined. The joint or node may be located, for example, at the center of the contact bridge. In one embodiment, the contact bridge may include recesses and / or openings located at the joints. The openings may at least partially penetrate the contact bridge along the switching direction.

[0017] In further embodiments, at least one joint may be offset along the switching direction with respect to the contact plane. The at least one offset joint may be, for example, a recess, a hollow, a depression, or a cavity. These configurations allow the contact bridge to be designed to accommodate additional elements and make the contact bridge subassembly more compact.

[0018] In a stable and easily manufactured embodiment of the contact bridge subassembly, the contact bridge may have a Y-shape. In particular, the legs on which the contacts are located may be arranged in a Y-shape. In another embodiment, the contact bridge, particularly the legs on which the switching contacts are located, may have a tuning fork shape. At least all the legs on which the switching contacts are located may extend parallel to each other.

[0019] In another advantageous embodiment, the contact bridge subassembly may include a spring assembly supporting the contact bridge, the spring assembly comprising at least one spring element. This ensures that the contact bridge is pressed sufficiently firmly against the fixed contact during operation to achieve good electrical contact.

[0020] At least one spring element of the spring assembly may be supported or seated on the side of the contact bridge opposite to the switching contact. At least one spring element of the spring assembly may be fixed to the contact bridge. At least one spring element of the spring assembly may be fixed to the contact bridge by a shape fit, for example, such as the spring element engaging with a recess in the contact bridge. Additional or cumulative, a friction lock may be achieved between at least one spring element of the spring assembly and the contact bridge, for example, by friction-reinforced surfaces of the spring element and / or friction-reinforced surfaces of the contact bridge. Furthermore, material locks such as welding or bonding may be used to fix at least one spring element of the spring assembly to the contact bridge. Naturally, combinations of different fastening methods are also conceivable, for example, in the form of screw connections.

[0021] In another embodiment, at least one spring element of the spring assembly, preferably all spring elements, are movably positioned on the contact bridge. In this case, the contact bridge and / or at least one spring element of the spring assembly may have a friction-reducing surface in the region where the spring element is supported on the contact bridge, or in other words, where it sits.

[0022] In a preferred embodiment, at least one spring element of the spring assembly is a coil spring, leaf spring, or flat spring, or comprises such a spring. If two or more spring elements are provided, different spring types may be used for the spring elements. For example, one spring element may be a leaf spring, another a flat spring, and yet another a coil spring. The spring elements may be connected in series and / or parallel. The spring elements may have different spring stiffnesses, or all spring elements may have the same spring stiffness.

[0023] The spring element may consist of at least two separate (sub)springs connected in series and / or parallel. These separate springs can be configured in various ways, as described above for the spring element.

[0024] According to a further embodiment of the contact bridge subassembly, at least one of the at least three legs may be supported by at least one spring element of the spring assembly. This is a particularly reliable method of ensuring, at least, that the switching contacts positioned on the supported leg make full contact with the fixed contacts during operation.

[0025] All legs on which the switching contacts are arranged may be supported by at least one spring element of the spring assembly. At least two of the spring elements by which different legs are supported may be joined to each other, for example, by a welded connection or a screw connection, or alternatively connected to each other. In one embodiment, at least two spring elements by which different legs are supported may be integrally formed with each other.

[0026] To reduce manufacturing costs, one spring element or at least two joined spring elements may be made from a punched and bent metal part.

[0027] In a particularly advantageous embodiment of the contact bridge subassembly, the spring assembly may comprise at least two spring elements that are deflectable independently of each other. This configuration enables the contact bridge to be supported by the spring elements to different extents at different locations. For example, at least two legs of the contact bridge, each having a switching contact, may be supported independently of each other, thereby improving the electrical contact at each of the switching contacts.

[0028] In one embodiment, the spring assembly may comprise a plurality of spring elements that are all deflectable independently of each other. Each of the legs on which the switching contacts are arranged may be supported by a spring element that is deflectable independently of each other. Of course, it is also contemplated that at least one of the legs is provided with two or more spring elements that are deflectable independently of each other, or alternatively deformable. Of course, the legs on which the switching contacts are not arranged may similarly comprise at least one spring element.

[0029] To distribute the mechanical load among the spring elements and enhance the buckling safety, the contact bridge subassembly may include at least one stiffening member for supporting the spring assembly. Each spring element of the spring assembly may have two support portions at both ends. One support portion is located on the contact bridge, and the other support portion is connected to the stiffening member. The stiffening member may be adapted to at least partially receive the mechanical load of at least two spring elements and / or stabilize the spring elements. The stiffening member may have a greater hardness and / or rigidity and / or material thickness than at least one spring element of the spring assembly. In various embodiments, at least one stiffening member may be connected to the spring assembly by welding, riveting, screwing, or adhesion. Of course, a single spring element of the spring assembly may be connected to the stiffening member using a combination of the above fixing methods. Different spring elements of the spring assembly may be connected to the stiffening member using different types of fixing methods.

[0030] In one embodiment, the stiffening member may be formed monolithically with at least one spring element of the spring assembly, preferably all spring elements of the spring assembly. In a low-cost design, the stiffening member may be made of a punched and bent metal part such as a metal sheet.

[0031] In one embodiment, all spring elements of the spring assembly may be connected via a single stiffening member. At least two, preferably all spring elements, which support different legs of the contact bridge, may be joined by the stiffening member.

[0032] To bias the spring assembly of the contact bridge subassembly, thereby enabling the setting of a predetermined resistance of the switching contact during opening and closing, the contact bridge subassembly may include at least one contact bridge retainer adapted to hold the contact bridge in the direction of action of the spring assembly.

[0033] A contact bridge retainer may be provided to pre-tension the spring assembly. To do this, the contact bridge retainer may hold the contact bridge at a predetermined distance from the end of at least one spring element that faces away from the contact bridge. Thus, the distance may be measured along the switching direction.

[0034] At least one spring element of the reinforcing member and / or contact bridge retainer and / or spring assembly may be formed integrally with each other and / or may be made from a stamped and bent metal part, such as a metal sheet. To electrically isolate the contact bridge from other parts of the contact bridge subassembly and / or parts that interact with or surround the contact bridge subassembly, the contact bridge subassembly may include at least one insulator. At least one reinforcing member and / or contact bridge retainer and / or spring assembly may be at least partially embedded in the insulator, and in particular may be at least partially overmolded by the insulator. At least one spring element of the spring assembly may be embedded in an insulator at the end of at least one spring element that faces away from the contact bridge.

[0035] The insulator may be made of insulating material, at least partially, preferably completely, and may be formed in various forms, such as plates or blocks.

[0036] If electrical disconnection is achieved by another means, for example, elsewhere within the relay, the insulator may be omitted, and therefore the contact bridge subassembly will have no insulating elements at all.

[0037] The object of the present invention is further solved by a contact bridge assembly comprising a first contact bridge subassembly and a second contact bridge subassembly according to the present invention. Such a contact bridge assembly reduces electrical contact resistance by providing three additional switching contacts. In addition, the switching contacts of the first contact bridge subassembly may be opened and closed at different timings than the switching contacts of the second contact bridge subassembly.

[0038] The contact plane defined by the switching contacts of the first contact bridge subassembly may extend parallel to the contact plane defined by the switching contacts of the second contact bridge subassembly. In another embodiment, the contact plane defined by the switching contacts of the first contact bridge subassembly may be identical to the contact plane defined by the switching contacts of the second contact bridge subassembly.

[0039] In a cost-effective embodiment, the contact bridge of the first contact bridge subassembly and the contact bridge of the second contact bridge subassembly may be formed identically except for the arrangement of the switching contacts. The contact bridges may have the same base, which corresponds to the contact bridge in a state where the switching contacts are not arranged.

[0040] In one embodiment, the contact bridge of the first contact bridge subassembly and the contact bridge of the second contact bridge subassembly may have different lengths and / or thicknesses. The thickness may be measured along the switching direction. The length may be measured perpendicular to the switching direction.

[0041] To make the contact bridge assembly compact and robust, the contact bridges of the first contact bridge subassembly and the contact bridges of the second contact bridge subassembly may be interlaced (arranged to cross each other, or combined in an alternating manner). The contact bridges may also be interlocked, entangled, and / or inserted into, embedded in, or fitted into each other, and / or combined with each other. Advantageously, the contact bridges may be interlaced at at least one joint. The contact bridges of the first contact bridge subassembly and the contact bridges of the second contact bridge subassembly may overlap along the switching direction, at least partially, and particularly at at least one joint.

[0042] In one embodiment, the contact bridge of the first contact bridge subassembly may be formed straight, i.e., without an offset joint, while the contact bridge of the second contact bridge subassembly may have a joint that is offset along the switching direction with respect to the contact plane of the second contact bridge assembly. In this particular embodiment, the joint of the contact bridge of the first contact bridge subassembly may be located at the offset joint of the contact bridge of the second contact bridge subassembly.

[0043] In a preferred embodiment, both contact bridges may have complementary offset joints where the contact bridges overlap and / or interlock. Complementary offset joints may be present, in particular, when the contact bridges are identical except for the switching contacts.

[0044] The contact bridge of the first contact bridge subassembly may be spaced apart from the contact bridge of the second contact bridge subassembly along the switching direction, at least in the joint region. This means that a gap extending in the switching direction may exist between the two contact bridges, at least in the joint region.

[0045] The particularly compact design of the contact bridge assembly and the dense arrangement of the switching contacts are achieved according to further embodiments of the contact bridge assembly, where the legs of the contact bridge of the first contact bridge subassembly may be at least partially positioned between the two legs of the contact bridge of the second contact bridge subassembly.

[0046] The legs of the contact bridge of the first contact bridge subassembly may at least partially penetrate the gap between the two legs of the contact bridge of the second contact bridge subassembly.

[0047] A leg of the contact bridge of the first contact bridge subassembly, positioned between two legs of the contact bridge of the second contact bridge subassembly, may be longer than and / or protrude further outward than at least one of the legs of the contact bridge of the second contact bridge subassembly, with the leg of the first contact bridge subassembly positioned between them.

[0048] Similarly, a leg of the contact bridge of the first contact bridge subassembly positioned between two legs of the contact bridge of the second contact bridge subassembly may have a greater width and / or thickness and / or cross-section than at least one of the legs of the contact bridge of the second contact bridge subassembly, with the leg of the first contact bridge subassembly positioned between them.

[0049] In a further embodiment, at least one spring element may support the contact bridges of both the first and second contact bridge subassemblies. In this way, the construction effort, material input, and consequently the cost of the contact bridge assembly can be reduced.

[0050] In particularly cost-effective embodiments, only a single spring element may be provided to support the contact bridges of both the first and second contact bridge subassemblies.

[0051] At least one contact bridge retainer of the first contact bridge subassembly may be the same part as at least one contact bridge retainer of the second contact bridge subassembly. As a result, the contact bridge assembly may comprise only a single contact bridge retainer that holds both the contact bridge of the first contact bridge subassembly and the contact bridge of the second contact bridge subassembly in the direction of action of at least one spring element.

[0052] Similarly, at least one reinforcing member of the first contact bridge subassembly may be the same part as at least one reinforcing member of the second contact bridge subassembly. Thus, a contact bridge assembly may comprise only a single reinforcing member.

[0053] Similarly, at least one insulator of the first contact bridge subassembly may be the same component as at least one insulator of the second contact bridge subassembly, and therefore the contact bridge assembly may comprise only a single insulator.

[0054] The object of the present invention is further solved by an electrical switching device, the switching device may comprise at least one contact bridge subassembly and / or at least one contact bridge assembly according to the present invention, a drive shaft adapted to move the contact bridge integrally along the switching direction, and fixed contacts configured to make contact with the switching contacts.

[0055] Switching contacts and fixed contacts may together constitute an electrical circuit.

[0056] Each of the contact bridges, or any of the contact bridges, may be movable relative to the drive shaft. For example, each of the contact bridges, or any of the contact bridges, may be rotatable about the longitudinal axis of the drive shaft and / or pivotable about at least one pivot axis extending perpendicular to the longitudinal axis of the drive shaft. It is also conceivable that each of the contact bridges, or any of the contact bridges, may be movable, in particular, displaceable perpendicular to the longitudinal axis of the drive shaft.

[0057] At least one spring element, particularly its ends facing away from one or more contact bridges, may be supported at least indirectly by the drive shaft, so that the direction of action of at least one spring element pushes each of the one or more contact bridges away from the drive shaft. The direction of action of at least one spring element may extend along the switching direction.

[0058] In one embodiment, the drive shaft may be directly attached to or connected to at least one reinforcing member and / or at least one spring element. In this embodiment, there may be no insulator at all.

[0059] The drive shaft may be at least partially embedded in the insulator, and advantageously at least partially overmolded in the insulator, to electrically disconnect one or more contact bridges from the drive shaft. The head of the drive shaft may be embedded in the insulator, and the head of the drive shaft is located at the end of the drive shaft facing one or more contact bridges. The present invention will be described in more detail and illustratively below with reference to the drawings, according to several embodiments, the different features of which may be combined with each other as necessary in accordance with the general description above. Furthermore, features may be omitted from the following embodiments if the technical effect is not required for a particular application. Similarly, if the technical effect is essential for a particular application, the above-described features that are not present in the embodiments described below may be added.

[0060] In the following, the same reference numeral is used for elements that correspond to each other with respect to at least one structure and function. [Brief explanation of the drawing]

[0061] [Figure 1] This is a schematic perspective view of a contact bridge subassembly according to a possible embodiment. [Figure 2] This is a schematic perspective view of a contact bridge assembly according to a possible embodiment. [Figure 3] This is a schematic perspective view of a contact bridge assembly according to yet another embodiment. [Figure 4] This is a schematic perspective view of a contact bridge assembly according to yet another embodiment. [Figure 5] This is a schematic perspective view of an electrical switching device according to a possible embodiment. [Figure 6] This is a schematic perspective view of a contact bridge assembly according to yet another embodiment. [Figure 7] Figure 6 is a cross-sectional view of the contact bridge assembly shown. [Figure 8]This is a cross-sectional view of an electrical switching device according to another possible embodiment in an open state. [Figure 9] This is a cross-sectional view of the electrical switching device shown in Figure 8, which is in a partially closed state. [Figure 10] This is a cross-sectional view of the electrical switching device shown in Figure 8 in the closed state. [Modes for carrying out the invention]

[0062] Figure 1 shows a contact bridge subassembly according to a possible embodiment. The contact bridge subassembly 1 of the embodiment in Figure 1 comprises a contact bridge 2, three switching contacts 4, a spring assembly 7 having three spring elements 6, a reinforcing member 8, and an insulator 10.

[0063] In the embodiment shown in Figure 1, the contact bridge 2 may have a Y-shape, or in other words, a tuning fork shape. The contact bridge 2 may comprise three legs 12 joined to each other at a joint 14. In the illustrated embodiment, the longitudinal axes 16 of the legs 12 extend parallel to each other and perpendicular to the switching direction 18 in which the contact bridge 2 is movable. Naturally, the contact bridge 2 may have a different shape from the contact bridge 2 shown in Figure 1, for example, a star shape. In such an embodiment, the longitudinal axes 16 of the legs 12 may intersect, for example, at a common point that may be located at the center 20 of the contact bridge 2, particularly the centroid of the contact bridge 2.

[0064] In the embodiment shown in Figure 1, the legs 12 may have different widths 22 along the width direction 24. The width direction 24 may extend perpendicular to the longitudinal axis 16 of each leg 12 and perpendicular to the switching direction 18. The legs 12 of the contact bridge 2 may have the same thickness 26 measured along the switching direction 18, as shown in Figure 1. Also, in the example shown in Figure 1, the legs 12 have a length 28 measured along the longitudinal axis 16 of each leg 12. In the embodiment shown in Figure 1, all legs 12 have the same length 28. In other embodiments, at least two of the legs 12 may have different lengths 28 and / or thicknesses 26. Similarly, in some embodiments, all legs 12 may have the same width 22.

[0065] The contact bridge 2 is provided with exactly three switching contacts 4. These switching contacts 4 define one contact plane 30. In the embodiment shown in Figure 1, each switching contact 4 is located at the free end 32 of each leg 12 of the contact bridge 2. Of course, the switching contacts 4 may be located elsewhere on the contact bridge 2, in particular elsewhere on the legs 12. Not all of the switching contacts 4 do not necessarily have to be located on separate legs 12; two or three switching contacts 4 may be located on a common leg 12.

[0066] To improve electrical contact, the switching contact 4 in the embodiment of Figure 1 has a slightly rounded shape with a vertex 34 facing away from the contact bridge 2. Naturally, the switching contact 4 may be only partially rounded or flat. Different shapes of rounding, such as a domed switching contact 4, are also conceivable. Naturally, the material of the switching contact 4 cannot be seen in Figure 1. However, it should be noted that the switching contact 4 may be made of or composed of a material such as AgSnOx and / or a particularly conductive material such as fine silver, which is intended to carry high currents. Naturally, the switching contact 4 may be made of a different material.

[0067] The number of switching contacts 4 must be exactly three according to the present invention, but the number of legs 12 provided by the contact bridge 2 may be variable. Thus, according to different embodiments, the contact bridge 2 may have fewer than three legs 12, in which case each of the three switching contacts 4 is not located on a separate leg 12. Similarly, more legs 12 may be provided, for example, four or five legs 12. In other embodiments, the contact bridge 2 may have no legs 12 at all.

[0068] In the embodiment shown in Figure 1, the joint 14 is joined at a node to the legs 12 of the contact bridge 2 and is offset with respect to the contact plane 30 defined by the switching contacts 4. As shown in Figure 1, the offset joint 14 may form a recess 36 in the contact bridge 2 into which other elements, such as a part of another contact bridge 2, may be inserted.

[0069] Not all of the legs 12 of the contact bridge 2 need to be joined to each other, or in other words, connected, via the joints 14. For example, the joints 14 may connect only two of the legs 12 to each other. Unlike what is shown in Figure 1, several joints 14 may be provided, for example, two or three. In one embodiment, the legs 12 connected via the joints 14 may, in addition, be joined to each other via at least one further joint 14. However, in another embodiment, one of the joints 14 may connect other legs 12 that are different from those connected by at least one other joint 14. Several joints 14 may be connected to each other.

[0070] In the embodiment shown in Figure 1, the legs 12 are firmly joined to each other at the joint 14. In the contact bridge subassembly 1 of Figure 1, this firm connection is achieved because the contact bridge 2 is formed monolithically except for the switching contacts 4. Of course, the legs 12 may be firmly joined to each other at the joint 14 in other ways, for example, by welding or bonding. Rather than a firm connection as shown in Figure 1, at least two of the legs 12 may be connected to each other at the joint 14 in a movable, e.g., displaceable and / or swivelable and / or elastic manner. In a further embodiment, at least one of the legs 12 may be attached to the joint 14 in a removable and / or replaceable manner.

[0071] As can be seen in Figure 1, each of the leg portions 12 may be supported by a spring element 6 of the spring assembly 7 (designed here simply as a flat spring for illustrative purposes). In other embodiments, other spring types such as leaf springs or coil springs may be provided. Naturally, if two or more spring elements 6 are provided, those spring elements 6 may have different spring types. A single spring element 6 may also consist of several (sub)springs, each of which may have a different spring type.

[0072] In the embodiment shown in Figure 1, all the spring elements 6 are able to flex independently of each other, so that each leg 12 of the contact bridge 2 and thus each of the switching contacts 4 is supported independently of the other legs 12 or switching contacts 4. In other embodiments, of course, the spring elements 6 may be arranged so that they can only flex together.

[0073] In the embodiment shown in Figure 1, each spring element 6 has two support portions 38 at both ends 72 of each spring element 6. One support portion 38 may be seated on the side 40 of the contact bridge 2 that faces away from the switching contact 4. In particular, each of the support portions 38 positioned on the contact bridge 2 may be seated on the free end 32 of the leg portion 12 of the contact bridge 2. In the embodiment shown in Figure 1, the support portions 38 positioned on the contact bridge 2 are firmly connected to the leg portion 12 of the contact bridge 2. For example, the fixing method may be a welded connection, a riveted connection, a screw connection, or a soldered connection. In other embodiments, at least one spring element 6, preferably all of the spring elements 6, may be movably positioned on the contact bridge 2. In particular, in this case, as shown in the embodiment of Figure 4, a contact bridge holder 42 may be provided, which is adapted to hold the contact bridge 2 in the direction of action 44 of the spring element 6. The structure and function of the contact bridge holder 42 will be described in more detail later.

[0074] In the embodiment shown in Figure 1, all support portions 38 facing away from the contact bridge 2 are connected to and, by extension, to the stiffening member 8. The stiffening member 8 can be adapted to at least partially absorb mechanical loads, such as the bending moment of the spring elements 6, and / or to distribute these loads among the spring elements 6. This reduces the likelihood that the spring elements 6 will experience a reduction in force due to the positional offset of the switching contacts 4. In the embodiments shown in Figures 1 and 2, the stiffening member 8 is formed as a plate extending along the contact plane 30 defined by the switching contacts 4. Naturally, the reinforcing member 8 can also be molded into different shapes in other embodiments, such as as a block.

[0075] To electrically isolate the contact bridge 2 from other components that may potentially interact with the contact bridge subassembly 1, the contact bridge subassembly 1 shown in Figure 1 includes an insulator 10. In the embodiment shown in Figure 1, the reinforcing member 8 is embedded in the insulator 10, but the support portion 38 facing away from the contact bridge 2 is not surrounded by the insulator 10. In other embodiments, the spring elements 6 of the spring assembly 7 may be received by the insulator 10 at least at their support portions 38 facing away from the contact bridge 2.

[0076] Figure 2 shows a contact bridge assembly 46 according to a possible embodiment. The contact bridge assembly 46 comprises a first contact bridge subassembly 1, 1a and a second contact bridge subassembly 1, 1b. The contact bridge 2 of the first contact bridge subassembly 1, 1a may be identical to the contact bridge 2 of the contact bridge subassembly 1 shown in Figure 1. The contact bridge 2 of the second contact bridge subassembly 1, 1b may be identical to the contact bridge 2 of the first contact bridge subassembly 1, 1a, except for the arrangement of the switching contacts 4.

[0077] As shown in the embodiment in Figure 2, each contact bridge 2 has exactly three switching contacts 4, each positioned at the free end 32 of the leg portion 12. The switching contacts 4 of the contact bridge 2 of the first contact bridge subassemblies 1, 1a define the first contact planes 30, 30a, and the switching contacts 4 of the contact bridge 2 of the second contact bridge subassemblies 1, 1b define the second contact planes 30, 30b. In the unloaded state of the contact bridge assembly 46 shown in Figure 2, the first contact planes 1, 1a and the second contact planes 1, 1b may extend parallel to each other.

[0078] In the embodiment shown in Figure 2, the contact bridge 2 of the first contact bridge subassembly 1, 1b and the contact bridge 2 of the second contact bridge subassembly 1, 1b are intertwined, so the joints 14 of both contact bridges 2 overlap each other along the switching direction 18. Furthermore, the first legs 12, 12a of the contact bridge 2 of the first contact bridge subassembly 1, 1a may be positioned between the second legs 12, 12e and the third legs 12, 12f of the contact bridge 2 of the second contact bridge subassembly 1, 1b, and the first legs 12, 12d of the contact bridge 2 of the second contact bridge subassembly 1, 1b may be positioned between the second legs 12, 12b and the third legs 12, 12c of the contact bridge 2 of the first contact bridge subassembly 1, 1a. In the embodiment shown in Figure 2, the first legs 12, 12a, and 12d of both contact bridges 2 have a greater width than the second legs 12, 12b, and 12e and the third legs 12, 12c, and 12f of the contact bridges 2.

[0079] In other embodiments, the contact bridge assembly 46 may comprise contact bridge subassemblies 1, 1a, 1b having contact bridges 2 formed in different shapes. For illustrative purposes only, the first legs 12, 12a of the contact bridge 2 of the first contact bridge subassembly 1, 1a may have a longer length 28 than the second legs 12, 12e and / or third legs 12, 12f of the contact bridge 2 of the second contact bridge subassembly 1, 1b. In particular, the free ends 32 of the first legs 12, 12a of the contact bridge 2 of the first contact bridge subassembly 1, 1a may protrude further away from the center 20 of the contact bridge 2 than the free ends 32 of the second legs 12, 12e and / or the free ends 32 of the third legs 12, 12f of the contact bridge 2 of the second contact bridge subassembly 1, 1b.

[0080] In the embodiment shown in Figure 2, each of the legs 12, 12a-12f of the contact bridge 2 of the first contact bridge subassemblies 1, 1a and the second contact bridge subassemblies 1, 1b is supported by the spring elements 6 of the spring assembly 7. Similar to the embodiment shown in Figure 1, all the spring elements 6 are flexible independently of each other. The contact bridge assembly 46 in Figure 1 comprises a single reinforcing member 8 to which all the spring elements 6 are joined via their supports 38 facing away from the contact bridge 2.

[0081] As can be seen from Figure 3, it is not necessary for all spring elements 6 of the spring assembly 7 to be joined to a single reinforcing member 8. In the embodiment of the contact bridge assembly 46 shown in Figure 3, there are three reinforcing members 8, each joined to both the leg portion 12 of the contact bridge 2 of the first contact bridge subassembly 1, 1a and the leg portion 12 of the contact bridge 2 of the second contact bridge subassembly 1, 1b.

[0082] The contact bridge assembly 46 shown in Figure 4 is substantially identical to the contact bridge assembly 46 shown in Figure 3, except that the contact bridge assembly 46 in Figure 4 includes an insulator 10 and a contact bridge retainer 42. As shown in Figure 4, the reinforcing member 8 may be completely embedded in the insulator 10. In the embodiment shown in Figure 4, the insulator 10 is adapted to electrically isolate both the contact bridge 2 of the first contact bridge subassembly 1, 1a and the contact bridge 2 of the second contact bridge subassembly 1, 1b from other components. Thus, the insulator 10 can be part of both the first contact bridge subassembly 1, 1a and the second contact bridge subassembly 1, 1b.

[0083] As further shown in Figure 4, the contact bridge holder 42 may be at least partially embedded in the insulator 10, particularly at the end 50 of the contact bridge holder 42 facing away from the contact bridge 2. In the embodiment shown in Figure 4, the contact bridge holder 42 comprises two brackets 52 arranged in a V-shape with respect to both the first contact bridge subassemblies 1, 1a and the second contact bridge subassemblies 1, 1b, and surrounds both contact bridges 2. In this way, the contact bridge holder 42 may hold both contact bridges 2 with respect to the direction of action 44 of the spring element 6. Of course, the arrangement of the brackets 52 is not limited to the V-shape described above. In other embodiments, other arrangements of the brackets 52, such as a U-shape or a Z-shape, are also conceivable.

[0084] Figure 5 shows an electrical switching device 54 according to a possible embodiment. The electrical switching device 54 comprises a contact bridge assembly 46, a drive shaft 56, and fixed contacts 58. The contact bridge assembly 46 shown in Figure 5 is identical to the contact bridge assembly 46 described with reference to Figure 4, except that a contact bridge holder 42 is not provided. In the embodiment of Figure 5, the head 60 of the drive shaft 56 is housed in an insulator. The head may be overmolded, for example, by an insulator 10.

[0085] The drive shaft 56 may be adapted to move the contact bridge 2 integrally along the switching direction 18. To switch the electrical switching device 54, the contact bridge 2 may move integrally along the switching direction 18. To close the switching device 54 and thus the electrical circuit, the contact bridge 2 may move together toward the fixed contact 58 until the switching contact 4 makes contact with the fixed contact 58 to be contacted. To open the electrical switching device 54 and thereby interrupt the electrical circuit, the contact bridge 2 may move integrally toward the fixed contact 58 until the switching contact 4 no longer makes contact with the fixed contact 58.

[0086] Figures 6 and 7 show a contact bridge assembly 46 according to another possible embodiment. The contact bridge assembly 46 shown in Figures 6 and 7 comprises a first contact bridge subassembly 1, 1a and a second contact bridge subassembly 1, 1b.

[0087] The first contact bridge subassemblies 1, 1a include a contact bridge 2 having a structure similar to that of the second contact bridge subassemblies 1, 1b shown in Figure 2. In short, the contact bridge 2 of the first contact bridge subassemblies 1, 1a shown in Figures 6 and 7 has a Y-shape and includes three legs 12. The contact bridge 2 is provided with exactly three switching contacts 4, each of which, in the embodiments shown in Figures 6 and 7, is positioned at the free end 32 of a different leg 12, defining the first contact planes 30, 30a. As can be further seen from Figures 6 and 7, the legs 12 of the contact bridge 2 of the first contact bridge subassemblies 1, 1a may be joined at a joint 14, which in the embodiments shown in Figures 6 and 7 is aligned with the switching direction 18 and offset with respect to the first contact planes 30, 30a.

[0088] The first contact bridge subassemblies 1, 1a may further comprise a spring assembly 7 having a spring element 6, the spring element 6 may be configured as a coil spring rather than a flat spring in the embodiments shown in Figures 6 and 7. The spring element 6 may include two support portions 38, one of which may seat in a first circular recess 62 formed in the contact bridge 2 of the first contact bridge subassemblies 1, 1a. The other support portion 38 of the spring element 6 may seat in a first pressure plate 64, the first pressure plate 64 may be located on the base portion 66 of an insulator 48 in the embodiments shown in Figures 6 and 7. The base portion 66 of the insulator 48 may extend substantially parallel to the first contact planes 30, 30a. The spring element 6 may push the contact bridge 2 of the first contact bridge subassemblies 1, 1a and the insulator 10 apart along the direction of action 44 of the spring element 6. In the embodiments of Figures 6 and 7, the direction of action 44 of the spring element 6 of the first contact bridge subassemblies 1, 1a extends along the switching direction 18.

[0089] The insulator 10 may further include a collar portion 68 that extends along the switching direction 18 and toward the first contact planes 30, 30a. In the embodiments shown in Figures 6 and 7, the spring element 6 of the first contact bridge subassemblies 1, 1a at least partially coaxially surrounds the collar portion 68 of the insulator 10. The spring element 6 of the first contact bridge subassemblies 1, 1a may be stabilized by the collar portion 68 of the insulator 10.

[0090] The second contact bridge subassemblies 1, 1b shown in Figures 6 and 7 include a contact bridge 2 having a Y-shape and comprising three legs 12. The contact bridge 2 of the second contact bridge subassemblies 1, 1b is provided with exactly three switching contacts 4 that define the second contact planes 30, 30b. In the embodiments shown in Figures 6 and 7, the switching contacts 4 are each located at the free end 32 of a different leg 12. As further shown in Figures 6 and 7, the legs 12 of the contact bridge 2 of the first contact bridge subassemblies 1, 1a may be joined at a joint 14. However, the joint 14 of the contact bridge 2 of the second contact bridge subassemblies 1, 1b does not have to be offset with respect to the second contact planes 30, 30b. In practice, the contact bridge 2 of the second contact bridge subassemblies 1, 1b in the embodiments of Figures 6 and 7 extends straight along the second contact planes 30, 30b.

[0091] The second contact bridge subassemblies 1, 1b may further comprise a spring assembly 7 having a spring element 6, the spring element 6 being a coil spring in the embodiments shown in Figures 6 and 7. One of the support portions 38 of the spring element 6 may be received and supported in a second circular recess 70 formed in the contact bridge 2 of the second contact bridge subassemblies 1, 1b. The other support portion 38 of the spring element 6 may seat on a second pressure plate 74, the second pressure plate 74 may be located on a ground surface 76 of the collar portion 68 of the insulator 10 in the embodiments shown in Figures 6 and 7. The ground surface 76 may extend substantially parallel to the first contact planes 30, 30a and the second contact planes 30, 30b. The spring element 6 of the second contact bridge subassemblies 1, 1b may push the contact bridge 2 of the second contact bridge subassemblies 1, 1b and the insulator 10 apart along the direction of action 44 of the spring element 6.

[0092] In the embodiments shown in Figures 6 and 7, the spring elements 6 of the second contact bridge subassemblies 1, 1b may be partially positioned within the opening 78 of the insulator 10, which is surrounded by the collar portion 68. The spring elements 6 of the first contact bridge subassemblies 1, 1a may further surround the spring elements 6 of the second contact bridge subassemblies 1, 1b at least partially coaxially.

[0093] The contact bridge assembly 46 shown in Figures 6 and 7 further comprises a contact bridge holder 42. In the embodiments shown in Figures 6 and 7, the contact bridge holder 42 is designed as a substantially U-shaped bracket that grips both contact bridges 2 on the side where the switching contacts 4 are provided. As shown in Figures 6 and 7, the contact bridge holder 42 may be attached to the first pressure plate 64, for example, via a locking portion 80. Similar to the embodiment in Figure 4, the contact bridge holder 42 may hold the spring element 6 in the direction of action 44 of the spring element 6. This makes it possible to preload the spring element 6 by adjusting its axial length 82, which can be measured between both ends 72 of the spring element 6.

[0094] In the embodiments shown in Figures 6 and 7, the contact bridge 2 of the first contact bridge subassembly 1, 1a and the contact bridge 2 of the second contact bridge subassembly 1, 1b are interlocked, so the joints 14 of both contact bridges 2 overlap each other along the switching direction 18. The first legs 12, 12a of the contact bridge 2 of the first contact bridge subassembly 1, 1a may be partially positioned between the second legs 12, 12e and the third legs 12, 12f of the contact bridge 2 of the second contact bridge subassembly 1, 1b, and the first legs 12, 12d of the contact bridge 2 of the second contact bridge subassembly 1, 1b may be partially positioned between the second legs 12, 12b and the third legs 12, 12c of the contact bridge 2 of the first contact bridge subassembly 1, 1b. In the embodiments shown in Figures 6 and 7, all legs 12 of both contact bridges 2 may have the same width 22.

[0095] Unlike the embodiment shown in Figure 2, the contact bridge 2 of the contact bridge assembly 46 shown in Figures 6 and 7 may have different external dimensions 84. In the embodiments shown in Figures 6 and 7, the external dimensions 84 may be measured along the longitudinal axis 16 of the leg portion 12. In particular, the contact bridge 2 of the first contact bridge subassembly 1, 1a may have a larger external dimension 84 than the contact bridge 2 of the second contact bridge subassembly 1, 1b.

[0096] In the following, the functions of an electrical switching device 54 according to another embodiment will be described with reference to Figures 8 to 10 as merely illustrative examples.

[0097] The electrical switching device 54 shown in Figures 8 to 10 comprises a contact bridge assembly 46, a fixed contact 58, and a drive shaft 56 according to the embodiments shown in Figures 6 and 7. The drive shaft 56 may be connected to the insulator 10 to transmit motion. In the embodiments described, the head 60 of the drive shaft 56 may be mounted in a complementaryly formed opening 78 on the side 86 of the insulator 10 that faces away from the contact bridge 2.

[0098] The drive shaft 56 does not necessarily have to be embedded in the insulator 10. In other embodiments, for example, the drive shaft 56 may be directly attached to or connected to at least one reinforcing member 8 and / or at least one spring element 6 of the spring assembly 7. In these embodiments, the insulator 10 may not be present at all.

[0099] Initially, the electrical switching device 54 may be in an open state 88. Since both the first contact planes 30, 30a and the second contact planes 30, 30b are spaced apart from the fixed contact 58 along the switching direction 18, no current flows between the fixed contact 58 and the switching contact 4. The electrical circuit between the fixed contact 58 and the switching contact 4 is open. In the open state 88, the switching contact 4 of the second contact bridge subassembly 1, 1b may be spaced a shorter distance from the fixed contact 58 along the switching direction 18 than the switching contact 4 of the first contact bridge subassembly 1, 1a.

[0100] To switch the electrical switching device 54 and close the electrical circuit, the drive shaft 56 moves the fixed bridge 2 integrally toward the fixed contact 58 until the switching contact 4 of the second contact bridge subassembly 1, 1b makes contact with the fixed contact 58 (see Figure 9). In this partially closed state 90, the electrical circuit between the switching contact 4 of the second contact bridge subassembly 1, 1b and the fixed contact 58 is already closed, but the switching contact 4 of the first contact bridge subassembly 1, 1a has not yet made contact with the fixed contact 58.

[0101] The drive shaft 56 further moves the contact bridge 2 of the first contact bridge subassembly 1, 1a so that the switching contact 4 of the first contact bridge subassembly 1, 1a also contacts the fixed contact 58. By doing so, the spring element 6 of the spring assembly 7 of the second contact bridge subassembly 1, 1b is compressed in its direction of action 44, so that the switching contact 4 of the second contact bridge subassembly 1, 1b is firmly and securely pressed against the fixed contact 58. When the switching contact 4 of the first contact bridge subassembly 1, 1a also contacts the fixed contact 58, the electrical switching device 54 is in a fully closed state 92 (see Figure 10). As soon as the switching contact 4 of the first contact bridge subassemblies 1, 1a makes contact with the fixed contact 58, the spring element 6 of the spring assembly 7 of the first contact bridge subassemblies 1, 1a is compressed in its direction of action 44, and as a result the switching contact 4 of the first contact bridge subassemblies 1, 1a is firmly and securely pressed against the fixed contact 58.

[0102] To press the contact bridge 2 against the fixed contact 58 with different forces, the spring elements 6 of the first contact bridge subassembly 1, 1a and the spring elements 6 of the second contact bridge subassembly 1, 1b may have different spring stiffnesses. For example, the spring elements 6 of the contact bridge subassembly 1 that are closer to the fixed contact 58 when the contact plane 30 is open 88 may have greater spring stiffness than the spring elements 6 of the contact bridge subassembly 1 that are further away from the fixed contact 58 when the contact plane 30 is open 88.

[0103] To switch the electrical switching device 54 back to the open state 88, that is, to open the electrical circuit, the drive shaft 56 moves the contact bridge 2 collectively along the switching direction 18 and away from the fixed contacts 58 until all the switching contacts 4 are separated again from the fixed contacts 58. [Explanation of Symbols]

[0104] 1. Contact bridge subassembly 1a First Contact Bridge Subassembly 1b Second Contact Bridge Subassembly 2 Contact Bridge 4 Switching Contacts 6 spring elements 7. Spring Assembly 8 Reinforcement member 10 Insulator 12 Legs 12a First leg of the contact bridge of the first contact bridge subassembly 12b Second leg of the contact bridge of the first contact bridge subassembly 12c Third leg of the contact bridge of the first contact bridge subassembly 12d First leg of the contact bridge of the second contact bridge subassembly 12e Second leg of the contact bridge of the second contact bridge subassembly 12f Third leg of the contact bridge of the second contact bridge subassembly 14 Joint 16 Longitudinal axis of the leg 18 Switching direction 20 Center of the Contact Bridge 22 Leg width 24 Width direction 26 Leg thickness 28 Leg length 30. Contact plane 30a First contact plane 30b Second contact plane 32 Free end 34 vertices 36. Indentation 38 Support part 40. The side of the contact bridge that faces away from the switching contacts. 42 Contact bridge retainer 44 Direction of action 46 Contact Bridge Assembly 48 Insulator 50 The end of the contact bridge holder that faces away from the contact bridge. 52 brackets 54 Electrical switching devices 56 Drive shaft 58 Fixed Contact 60 Drive shaft head 62 First circular depression 64 First pressure plate 66 Insulator base 68 Insulator color part 70 Second circular depression 72 End of spring element 74 Second pressure plate 76. Colored part of the seat (ground, base) 78 Insulator opening 80 Lock section 82 Axial length 84 External dimensions of the contact bridge 86. Of the insulators, the side facing away from the contact bridge. 88 Open state 90 Partially closed state 92. Completely closed state

Claims

1. A contact bridge subassembly (1, 1a, 1b) for an electrical switching device (54) such as a relay or contactor, The system includes a contact bridge (2) that is movable along the switching direction (18), A contact bridge subassembly (1, 1a, 1b) is provided, wherein exactly three switching contacts (4) are arranged on the contact bridge (2), and the three switching contacts (4) define a single contact plane (30, 30a, 30b).

2. The contact bridge subassembly (1, 1a, 1b) according to claim 1, wherein the contact bridge (2) comprises at least three legs (12, 12a to 12f), and each of the switching contacts (4) is positioned on a different leg (12, 12a to 12f).

3. The contact bridge subassembly (1, 1a, 1b) according to claim 2, wherein at least two of the leg portions (12, 12a to 12f) are joined to each other at at least one joint portion (14).

4. The contact bridge subassembly (1, 1a, 1b) according to claim 3, wherein the at least one joint (14) is offset along the switching direction (18) with respect to the contact plane (30, 30a, 30b).

5. The contact bridge subassemblies (1, 1a, 1b) according to any one of claims 1 to 4, wherein the contact bridge subassemblies (1, 1a, 1b) comprises a spring assembly (7) supporting the contact bridge (2), and the spring assembly (7) comprises at least one spring element (6).

6. The contact bridge subassembly (1, 1a, 1b) according to claim 5, wherein the spring assembly (7) comprises at least two spring elements (6) that are flexible independently of each other.

7. The contact bridge subassemblies (1, 1a, 1b) include at least one reinforcing member (8) for supporting the spring assembly (7), The contact bridge subassembly (1, 1a, 1b) according to claim 5 or 6, wherein each spring element (6) of the spring assembly (7) is provided with two support portions (38) at both ends (72), one support portion (38) located on the contact bridge (2) and the other support portion (38) connected to the reinforcing member (8).

8. The contact bridge subassembly (1, 1a, 1b) according to any one of claims 5 to 7, comprising at least one contact bridge holder (42) adapted to hold the contact bridge (2) with respect to the direction of action (44) of the spring assembly (7).

9. A contact bridge subassembly (1, 1a, 1b) according to any one of claims 5 to 8 in combination with any one of claims 2 to 4, wherein at least one of the at least three legs (12, 12a to 12f) is supported by at least one spring element (6) of the spring assembly (7).

10. The contact bridge (2) is a Y-shaped contact bridge subassembly (1, 1a, 1b) according to any one of claims 1 to 9.

11. A first contact bridge subassembly (1, 1a) according to any one of claims 2 to 10, A second contact bridge subassembly (1, 1b) according to any one of claims 2 to 10 and A contact bridge assembly (46) comprising the above.

12. The contact bridge assembly (46) according to claim 11, wherein the contact bridge (2) of the first contact bridge subassembly (1, 1a) and the contact bridge (2) of the second contact bridge subassembly (1, 1b) are arranged alternately.

13. The contact bridge assembly (46) according to claim 11 or 12, wherein the legs (12, 12a to 12c) of the contact bridge (2) of the first contact bridge subassembly (1, 1a) are at least partially positioned between the two legs (12, 12d to 12e) of the contact bridge (2) of the second contact bridge subassembly (1, 1b).

14. A contact bridge assembly (46) according to any one of claims 11 to 13, wherein at least one spring element (6) supports the contact bridge (2) of both the first contact bridge subassembly (1, 1a) and the second contact bridge subassembly (1, 1b).

15. At least one contact bridge subassembly (1, 1a, 1b) according to any one of claims 1 to 10 and / or at least one contact bridge assembly (46) according to any one of claims 11 to 14, A drive shaft (56) is fitted to move the contact bridge (2) integrally along the switching direction (18), A fixed contact (58) configured to make contact with the switching contact (4) and An electrical switching device (54) equipped with the following features.

Images