Clamping group of switch with compact internal structure

Abstract

The present invention relates to a clamping group (31, 32) for a switch, a changeover switch, a disconnector or in general a power switch (1) mounted inside an insulating switch body (2) and comprising at least one movable contact (29) providing an electrical connection, said clamping group (31, 32) being configured to clamp said at least one movable contact (29) of said power switch (1), wherein a modular structure comprises a plurality of caliper-like elements (60) mounted in parallel on a support frame (46) and further comprising respective terminal finger-like elements (45) angularly movable with respect to each other, approaching and distancing each other against elastic return means (47).

Description

Technical Field

[0001] The present invention relates to a clamping assembly for a switch (e.g., a changeover switch) having an improved internal structure and functional configuration, as well as a more compact overall structure.

[0002] More specifically, but not exclusively, the present invention relates to a clamping assembly for a power switch suitable for industrial applications involving high currents, particularly in the railway sector. Background Technology

[0003] As is well known in this particular art, a switch is an electrical component that can "establish" or "disconnect" an electrical connection within a circuit to interrupt current or transfer it from one conductor to another. A switch, when operated, removes or restores a conductive path in a circuit.

[0004] A specific type of switch is called a disconnecting switch. Disconnecting switches are used to ensure complete de-energization of a circuit for repair or maintenance; however, during normal operation, they must be able to support normal current as well as short-circuit currents defined for the specific application without any indirect damage. These disconnecting switches are frequently used in power distribution and industrial applications where the power supply to the machinery must be removed during regulation or maintenance operations. High-voltage disconnecting switches are particularly used in substations to ensure the isolation of equipment such as circuit breakers, transformers, and transmission lines, especially during their maintenance. Disconnecting switches are generally not used to provide normal control of the circuit, but only to ensure safety isolation and therefore for managing that safety isolation. Disconnecting switches can be operated manually or automatically.

[0005] Unlike load switches and circuit breakers, disconnecting switches lack mechanisms to suppress arcing, which typically occurs when a conductor carrying a large current is interrupted. Therefore, they can be considered unloading devices, designed to open only after the current flowing in the connected conductor has been interrupted by using another control device.

[0006] In some known types of circuit breakers, when one contact is interrupted, another contact can be used to establish a connection with a different circuit.

[0007] This is what is known as a "changeover contact" or "changeover switch," in which a set of three electrical contacts is precisely configured to allow interruption of contact with one circuit and then establishment of a connection with another circuit.

[0008] A set of three contacts is typically called a pole. A changeover switch may have one or more poles. The contacts in a pole are made of hard, fire-resistant, and corrosion-resistant materials, such as properly treated copper and related alloys.

[0009] Even if they are useful, changeover switches are usually large and cannot be used frequently, especially in applications where space needs to be optimized to organize as much circuitry as possible within a limited area.

[0010] In view of this, for example, a space-safe internal moving mechanism has been developed for moving the active contact of a changeover switch.

[0011] Despite the undeniable advantages of this moving mechanism, the position of the moving contacts within the changeover switch cannot necessarily be fixed, as even a slight vibration of the switch itself could physically move one of these moving contacts and, unintentionally, interrupt the electrical connection provided by the switch.

[0012] On the other hand, known locking mechanisms for fixing the position of the moving contact introduce new problems related to achieving a compact construction of the switch, and in some cases, cannot even guarantee reliable locking of the moving contact position and thus cannot ensure that the switch provides a reliable electrical connection.

[0013] Moving contacts and internal locking mechanisms are also used in other types of switches, such as disconnecting switches, especially for industrial or railway applications, or general power switches. Summary of the Invention

[0014] Therefore, the technical problem of the present invention is to provide an internal locking mechanism for the internal moving contact of a switch to ensure its compact construction, especially in the case of a changeover switch.

[0015] Another object of the present invention is to provide a switch with an internal locking mechanism that ensures more efficient operation of the entire switch.

[0016] Another object of the present invention is to provide a switch having an internal structure that ensures high reliability and long service life.

[0017] Another object of the present invention is to provide a switch internal structure that does not require complex manufacturing steps and therefore does not require high manufacturing costs.

[0018] Finally, the object of this invention is to provide an internal structure for a switch that is easy to apply to different types of power switches.

[0019] The solution based on this invention is to use a clamping assembly of caliper-like elements to clamp the moving contact of the switch, thereby providing a locking device with a compact construction, strong locking force, and applicability to various moving contact shapes. Such clamping assemblies of caliper-like elements are widely used in the aforementioned fields; therefore, the particularity of this invention relates to a novel caliper shape design that reduces the overall size of the caliper assembly and the entire switch.

[0020] Based on the above-described solution concept, this technical problem is solved by a clamping assembly for switches, changeover switches, disconnect switches, and general power switches (particularly power switches for industrial or railway applications), which are mounted within an insulating body and include at least one movable contact providing electrical connection. The clamping assembly is configured to clamp the at least one movable contact of the power switch. The clamping assembly has a modular structure comprising multiple clamp-like elements mounted parallel to each other on a support frame and also including respective terminal fingers capable of moving at an angle relative to each other, approaching and moving away from each other against a resilient return mechanism.

[0021] Advantageously, this structural shape of the clamping assembly allows for a very compact overall structure including their switches, while ensuring effective operation in terms of mechanical stability and proper electrical connection.

[0022] Furthermore, the modular construction is advantageously an optimized design for switches of different sizes.

[0023] Preferably, each caliper-like element in the clamping assembly is formed by two terminal finger elements and is movable independently relative to other caliper-like elements in the same clamping assembly. Furthermore, the terminal finger elements of the caliper-like elements are movable independently relative to the terminal finger elements of other caliper-like elements in the same clamping assembly.

[0024] Advantageously, this independent movement allows the clamping assembly to be adapted to different active contact shapes, just like a hand when clamping the active contact.

[0025] According to a particular aspect of the invention, each terminal finger of the caliper-like element includes at least two holes near its two opposite ends.

[0026] Preferably, the clamping assembly according to the invention includes pins for each hole of the terminal finger element for the caliper-like element.

[0027] This structure ensures the packaging construction of the clamping assembly, thereby guaranteeing the spatial safety of the overall structure of the clamping assembly.

[0028] In addition, depending on the specific aspect, the support frame of the clamping assembly includes at least two support elements located at the ends of the clamping assembly to secure the packaging structure.

[0029] Preferably, the support element includes eyelets for pins corresponding to each hole of the terminal finger element, with at least two eyelets providing clearance relative to such pins.

[0030] Advantageously, due to this specific construction, the caliper-like elements of each clamping assembly can move correctly.

[0031] Furthermore, the support frame of the clamping assembly according to another aspect of the invention also includes an interconnecting beam on which the support element is mounted.

[0032] Advantageously, the construction is easy to manufacture and reliable in operation.

[0033] According to another aspect of the invention, the clamping assembly further includes bushings corresponding to each hole of the terminal finger element and between the caliper-like elements of the clamping assembly.

[0034] Furthermore, a spring-type elastic return device is preferably alternately located between the caliper-like elements of the clamping assembly.

[0035] This particular aspect allows each caliper-like element in each clamping assembly to move correctly and independently.

[0036] According to one particular aspect of the invention, the clamping assembly further includes a locking washer for each pin, which is located on the eyelet of the support element on the other side relative to the caliper-like element to ensure that the packaged structure of the caliper-like element of the clamping assembly is maintained.

[0037] According to another aspect of the invention, each caliper-like element has a terminal finger element with a rounded tip at one end, corresponding to the clamping portion of the corresponding caliper-like element.

[0038] Furthermore, preferably, the facing contours of the terminal finger elements of each caliper-like element form a convergence-diffusion space.

[0039] This specific shape of the terminal finger element facilitates the clamping stage while allowing for proper clamping of the moving contact.

[0040] Finally, it must be noted that the clamping assembly is suitable for any power switch, regardless of the current level, because different (increased or decreased) numbers of clamping elements can be installed to meet the required current rate.

[0041] Clearly, the ability to apply the same components to different switch models is a significant advantage in terms of production time and cost assessment.

[0042] Further features and advantages of the switch of the present invention will become more apparent from the following description, given by way of non-limiting example with reference to the accompanying drawings. Attached Figure Description

[0043] - Figure 1 A perspective view of a switch including a clamping assembly, implemented according to the present invention, is shown;

[0044] - Figure 2 A perspective view of the clamping assembly according to the present invention is shown;

[0045] - Figure 3It shows Figure 2 Exploded view of the clamping assembly;

[0046] - Figure 4 It shows Figure 2 Front view of the clamp-like element of the clamping assembly;

[0047] - Figure 5 It shows Figure 2 Side view of the clamping assembly;

[0048] - Figure 6 It shows Figure 2 A top view of the clamping assembly. Detailed Implementation

[0049] Referring to the accompanying drawings, reference numeral 1 schematically illustrates a switch, particularly a changeover switch, implemented according to the present invention.

[0050] The switch 1 shown is specifically designed for industrial or railway applications, where high DC currents must be switched on and off in order to perform high-frequency switching operations.

[0051] The switch 1 includes an insulated switch body 2, which in turn includes all the moving parts of the switch itself, as will be disclosed below.

[0052] exist Figure 1 The specific embodiment shown discloses a changeover switch, but the same mechanism can be applied to disconnect switches or is generally applied to power switches.

[0053] exist Figure 1 In the exemplary embodiment described, the switch body 2 has a generally parallelepiped shape, and its depth is much smaller than the other two dimensions.

[0054] In addition, specifically, Figure 1 A switch 1 is shown, with its front surface removed to show all the components housed in the switch body 2.

[0055] The switch body 2 includes a base 3, which is adapted to be connected to an electrical system via two recesses 4, or simply used as a support for the switch 1.

[0056] The switch 1 can be internally divided into two main parts: a lower part 5 near the base 3 and an upper part 7 standing above the lower part 5. A moving mechanism 6 is housed in the lower part, and an electrical connection assembly 8 is housed in the upper part. These spatial references relate to the installation of the switch extending in a vertical position, particularly according to the Y-axis of the local reference system shown in the figure.

[0057] The moving mechanism 6 includes a motor 9. The motor 9 is, for example, an electromagnetic coil. However, nothing prevents the use of other motors 9, such as an electric motor. The moving mechanism 6 is preferably a rotary motion mechanism.

[0058] The motor unit 9 is covered by a vertical partition 10 and a horizontal partition 11 to protect the motor unit 9 and to divide it into a lower part 5 and an upper part 7.

[0059] The motor 9 is also operatively connected to the gear system 12, which includes a main gear 13 and a secondary gear 14.

[0060] Shaft 15 is connected to the planar surface 16 of the main gear 13. Figure 1 In the exemplary embodiment shown, shaft 15 has three lug shapes, but there are no limitations on its use, such as a straight shaft 15.

[0061] The rod 17 is connected to a lug 19 on the shaft 15 at its end 18. In this way, the rotation of the main gear 13 causes the shaft 15 to rotate, and thus causes the rod 17 to translate.

[0062] In other words, shaft 13 and rod 17 are used as piston rod / crankshaft mechanism.

[0063] Rod 17 also provides a connection between the lower part 5 and the upper part 7.

[0064] The lever 17 has a U-shaped cross section at its opposite end 20 along the depth direction of the switch body 2, that is, the opposite end 20 is U-shaped along the Z-axis of the local reference system shown in the figure.

[0065] The cavity at the opposite end 20 of the U-shape is complementary to the supporting sliding element 21.

[0066] The supporting sliding element 21 includes a front plate 22 and a rear plate 23 arranged in parallel, approximately at their average dimensions, which are laterally connected in the depth direction of the switch body 2 by a connecting portion 24. In other words, the supporting sliding element 21 is H-shaped in the depth direction of the switch body 2.

[0067] The front plate 22 has a rectangular cross-section, with a recess 25 on its underside facing the rod 17. The recess 25 is inserted into a cavity at the opposite U-shaped end 20 of the rod 17 and is preferably secured by a transverse pin.

[0068] The rear plate 23 is on the rear surface 26 of the switch body 2.

[0069] Preferably, a guide 27 is inserted between the rear plate 23 and the rear surface 26 along the central axis of the switch body 2. In the described embodiment, the guide 27 has an Ω-shaped profile, and the rear plate 23 has a corresponding and complementary shape with a groove 28 for sliding on the Ω-shaped guide 27.

[0070] There are no restrictions on the use of other types of guides 27 on which the supporting sliding element 21 can slide.

[0071] The movable contact 29 is positioned on the upper side 30 of the connecting portion 24 and is secured, for example, by screws or bolts. The movable contact 29 is a strip or rod extending laterally relative to the guide 27.

[0072] In this way, the sliding of the supporting sliding element 21 causes the movable contact 29 to translate.

[0073] An opening 33 is provided on the side 44 of the switch body 2.

[0074] Terminal contact 34 extends through the opening 33.

[0075] Terminal contact 34 is associated with contact bar 35, which extends peripherally from the opening 33 on side 44 to the upper end 36 of the opposite side 37 of switch body 2.

[0076] At the two ends of the movable contact 29, there are two other openings 38 and 39 parallel to the opening 33.

[0077] exist Figure 1 In the illustrated embodiment, two corresponding terminal contacts 40 and 41 extend from openings 38 and 39. In a disconnecting switch, only terminal contact 40 extending from opening 38 will be provided. Clearly, terminal contact 34 is always present.

[0078] Two corresponding connecting elements 42 and 43 are disposed on opposite sides 37 of openings 38 and 39, and contact the contact bar 35. When the movable contact 29 is in its respective end position, the connecting elements 42 and 43 allow the contact bar 35 to connect with the movable contact 29 and to the corresponding terminal contacts 40 and 41, respectively.

[0079] In other words, depending on the position of the active contact 29 along the contact bar 35, two alternative connection configurations are provided between the terminal contact 34 and the terminal contacts 40, 41.

[0080] In the case of a disconnector switch, only one connecting element 42 will be provided.

[0081] Another feature of switch 1 is that there is an electronic board (not shown) on the outside of switch body 2 that is associated with the rear side of switch 1.

[0082] Specifically, the electronic board is configured to regulate the power supply to the motor 9. More specifically, according to this exemplary but non-limiting embodiment, the electronic board is configured to provide the correct voltage and current values ​​to the coil within a predetermined scheduled time.

[0083] These correct voltage and current values ​​are provided regardless of possible deviations from the main power supply and are available over an operating temperature range of -40°C to +75°C.

[0084] High-reliability operating conditions of the electronic board can be ensured by heat dissipation components and circuit recovery devices installed on the board.

[0085] In addition, in accordance with stricter railway requirements, the electronic boards are equipped with appropriate resistance to radiation and conducted interference.

[0086] For the entire low-voltage equipment of the device, additional specific insulation of at least 1500V (at 50Hz, within 60s) relative to ground is also provided.

[0087] Suitablely, at least one clamping assembly 31 is provided at the lower position supporting the sliding contact 21 and the movable contact 29 to ensure electrical connection and locking function. Preferably, two clamping assemblies 31 are provided at opposite ends of the slat movable contact 29. These clamping assemblies 31 are oriented upward and have corresponding clamping portions extending from below to the slat movable contact 29.

[0088] Conversely, at least two opposing clamping groups 32 can be provided at the upper positions supporting the sliding contact 21 and the movable contact 29. Preferably, when two disconnections or switching are required, two clamping groups 32 are provided at opposite ends of the movable contact 29.

[0089] The clamping assembly 32 has a corresponding clamping portion facing the clamping portion of the clamping assembly 31, and is thus oriented downward.

[0090] It should be emphasized that the configuration of two clamping assemblies 31 and two opposing clamping assemblies 32 for each active contact 29 position is preferred because this configuration ensures better structural balance.

[0091] In the disconnecting switch, only two terminal contacts are provided, so only one pair of clamping groups 31 can be used, but there is no restriction on using another pair of clamping groups for the open position, thus allowing continuity in different circuits when the continuity of the previous circuit is interrupted.

[0092] like Figures 2 to 5As specifically shown, clamping assembly 31 and the opposing clamping assembly 32 include suitable miniature caliper-like elements 60 adapted to releasably lock the movable contact 29 into place in two end positions, respectively. As will be explained below, these clamping assemblies 31, 32 act as hands on the movable contact 29 due to the miniaturized caliper-like elements 60.

[0093] More specifically, clamping assemblies 31, 32 include multiple clamp-like elements 60, which are mounted in parallel and modularly on a common support frame 46. Each clamp-like element 60 further includes a pair of terminal fingers 45, which are angularly movable relative to each other, approaching and moving away from each other against a resilient return device 47. The resilient return device 47 may be in the form of a spring connected to the terminal fingers 45. This working mechanism allows the clamping assemblies 31, 32, including the clamp-like elements 60, to function as a hand, while the terminal fingers 45 ensure clamping force with the movable contact 29 and allow for proper establishment of an electrical connection.

[0094] Specifically, it is advantageous that, according to the invention, the terminal finger element 45 of the caliper element 60 can move independently of the terminal finger element 45 of the other caliper elements 60 in the same clamping group 31, 32.

[0095] Furthermore, each caliper element 60 can move independently relative to the other caliper elements 60 of the clamping assemblies 31, 32.

[0096] The support frame 46 includes at least two support elements 48 located at the ends of the clamping assemblies 31 or 32 to secure the packaging structure. In this way, the clamping elements 60 of the clamping assemblies 31, 32 are properly contained and securely packaged between the support elements 48 of the support frame 46.

[0097] The support frame 46 also includes an interconnecting beam 49, on which the support element 48 is mounted. The interconnecting beam 49 is located at the end of the terminal finger element 45 opposite to the clamping portion 50 of the clamping element 60, and generally forms its base.

[0098] Specifically, the interconnecting beam 49 is arranged laterally relative to the clamping direction of the clamping assemblies 31 and 32.

[0099] The two mirror support elements 48 are H-shaped, with one leg longer than the other, and are parallel to the clamp-like elements 60 of the clamping assemblies 31, 32. On the longer leg of the support element 48, a protruding plate portion 51 in the direction of the interconnecting beam 49 is attached to the interconnecting beam 49. Thus, the protruding plate 51 is connected to the interconnecting beam 49 by bolts, screws, or similar means.

[0100] Each terminal finger element 45 includes at least two holes 52 near its two opposite ends. Each hole 52 receives a pin 53 adapted to secure clamping assemblies 31, 32 in a “packaging construction”.

[0101] Between the clamp-like elements 60 of the corresponding clamping groups 31, 32, a bushing 54 is provided at each hole 52 in the terminal finger element 45.

[0102] Furthermore, in the preferred exemplary embodiment described herein, the elastic return device 47 includes springs that are alternately disposed between the clamp-like elements 60 of the clamping assemblies 31, 32.

[0103] These springs 47 are arranged perpendicularly to the terminal finger element 45 and are held in place by pins 61 at the ends of the springs 47, which are fitted into corresponding traces 54 on the outer surface of the terminal finger element 45.

[0104] Preferably, the bushing 54 is thicker inside the pair of clamping elements 60 where the spring 47 is present, and thinner outside the pair of clamping elements where the spring 47 is absent.

[0105] This ingenuity allows for minimizing the size of the entire clamping assembly, but obviously a bushing 54 of the same size could also be used, for example, to simplify the production of the entire clamping assembly.

[0106] The support element 48 includes an eyelet 55 for each pin 53, corresponding to each hole 52 of the terminal finger element 45. The eyelet 55 at the clamping portion 50 provides a clearance H relative to the pin 53 to allow the opening movement of the clamping assemblies 31, 32.

[0107] In addition, a locking washer 56 is provided for each pin 53, which is located on the eyelet 55 on the opposite side relative to the caliper-like element 60. In this way, undesirable pull-out of the pin 53 from its seat is prevented.

[0108] In the exemplary embodiments described herein, the terminal finger element 45 also has a rounded tip T at the corresponding clamping portion 50.

[0109] Furthermore, in this embodiment, the facing contour 57 of the terminal finger element 45 forms a convergence-diffusion space between the terminal finger elements 45 themselves.

[0110] The special construction of clamping assemblies 31 and 32 allows for both quick engagement between the clamp-like element 60 and the movable contact 29 and stable positioning of the movable contact 29 under vibration, so as to ensure electrical connection and disconnection only under operating conditions.

[0111] Clamping assemblies 31 and 32 can be implemented in any power switch, especially for industrial or railway applications.

[0112] The operation of the clamping assemblies 31 and 32 according to the present invention will now be described.

[0113] The actuation of the motor 9 causes the gear system 12 to rotate. The rotation of the gear system 12 causes the rod 17 to translate, one end of which is connected to one end of the shaft 15. The translational movement of the rod 17 thus causes a push-pull action on the supporting sliding element 21 and therefore on the movable contact 29.

[0114] At the end positions of the supporting sliding element 21 and the movable contact 29, at least one, preferably two, clamp assemblies 31 and 32 are provided to hold the movable contact 21 in place.

[0115] Specifically, when the movable contact 29 arrives corresponding to the clamping groups 31 and 32, the shape of the corresponding clamping portion 50 causes the movable contact 29 to insert into the space between the terminal fingers 45 of the clamping elements 60 of the clamping groups 31 and 32. The insertion of the movable contact 29 into the converging portion of the space between these terminal fingers 45 causes the terminal fingers 45 themselves to move apart, each clamping element 60 moving independently relative to each other. The successive movements of the movable contact 29 within the spreading portion of the space between the terminal fingers 45 cause these terminal fingers 45 to approach each other, return to their original position, and reliably lock the movable contact 29 into place.

[0116] Conversely, when it is desired to move the movable contact 29, a force greater than that of the elastic return device 47 is applied to cause the movable contact 29 to move in opposite directions between the terminal fingers 45 of the clamping elements 60 of the clamping assemblies 31, 32.

[0117] Once the active contact 29 is in place, it forms a circuit with the following components: terminal contact 40 or 41; connecting element 42 or 43 on the opposite side of the switch body 2; and contact strip 35 that contacts the connecting element and extends peripherally to the terminal contact 34.

[0118] The described mechanism generates a pre-calculated pressure on the moving contact 29 to allow the switch to support rated current rates as well as short-circuit currents without damaging the equipment. The pressure on the moving contact 29 ensures appropriate contact resistance to reduce power dissipation under rated conditions and withstands the electrodynamic strength generated by abnormal currents under short-circuit conditions.

[0119] In a disconnector switch that has only two terminal contacts 34 and 40, the movement of the movable contact 29 between the operating position and the disconnected position is anticipated.

[0120] Advantageously, according to the invention, the switch thus obtained has a compact structure due to its internal construction, thanks to the clamping assemblies 31, 32 including a clamp-like element 60, which is provided with terminal finger elements 45, so as to ensure that the movable contact 29 is mechanically clamped in place, thereby providing the required electrical contact.

[0121] Furthermore, advantageously, this solution can be applied to both disconnecting switches and other transfer switches.

[0122] Advantageously, the clamping assembly and caliper-like element of the present invention have a simple yet highly effective operation.

[0123] Another advantage is that the clamping assembly offers greater reliability and quick, inexpensive maintenance.

[0124] This invention is applicable to most applications requiring high-current switching.

[0125] Another advantage of this invention is that it does not require specific manufacturing, which is important for parts that are clearly intended for mass production.

[0126] Finally, the clamping assembly and switch according to the invention can also be used as switches in high AC current applications.

[0127] In the preceding description, directional terms such as “forward,” “backward,” “front,” “back,” “up,” “down,” “above,” “below,” “upward,” “downward,” “top,” “bottom,” “side,” “vertical,” “horizontal,” “vertical,” and “lateral,” as well as any other similar directional terms, refer only to the device shown in the accompanying drawings and do not relate to any possible use of the device. Therefore, when used to describe a contactor in a vertical position on a horizontal surface, these directional terms mean only to identify a part of the device relative to another part of the device, as shown in the figures.

[0128] As used herein, the term "comprising" and its derivatives are open-ended terms that specify the presence of the stated feature, element, component, group, integer, and / or step, but do not exclude the presence of other unstated features, elements, components, groups, integers, and / or steps. This concept also applies to words with similar meanings, such as the terms "having," "comprising," and their derivatives.

[0129] Furthermore, when used in the singular, the terms “component,” “section,” “part,” “section,” and “element” can have a dual meaning of a single part or multiple parts.

Claims

1. A clamping assembly (31, 32) for a switch, changeover switch, disconnector switch or general power switch (1), the power switch (1) being mounted within an insulated switch body (2) and including at least one movable contact (29) providing electrical connection, the clamping assembly (31, 32) being configured to clamp the at least one movable contact (29) of the power switch (1). Its features are, The clamping assembly has The modular structure includes a plurality of clamp-like elements (60) mounted parallel to each other on a support frame (46) and also includes respective terminal fingers (45) capable of moving at an angle relative to each other, approaching and moving away from each other against resilient return devices (47), wherein each of the resilient return devices (47) is alternately located between the clamp-like elements (60) of the clamping assemblies (31, 32), wherein the resilient return device (47) is arranged perpendicularly to the terminal fingers (45) and held in place by pins (61) at the ends of the resilient return devices (47), the pins (61) being fitted in corresponding traces on the outer surface of the terminal fingers (45). Each terminal finger element (45) of the caliper-like element (60) includes at least two holes (52) located near two opposite ends of the terminal finger element (45). The clamping assemblies (31, 32) further include pins (53) for each hole (52) of the terminal finger element (45) of the caliper element (60). The support frame (46) includes at least two support elements (48) located at the ends of the clamping assemblies (31, 32) to ensure the packaging structure of the caliper-like element (60), and The support element (48) includes eyelets (55) for the pin (53), the eyelets corresponding to the holes (52) of the terminal fingers (45), at least two eyelets (55) on the side for receiving the movable contact (29) for the pin (53) to pass through the holes (52) of the terminal fingers (45) provide gaps (H) relative to the pin (53) to allow opening movement of the clamping assembly (31, 32), wherein the eyelets (55) on the side of the terminal fingers (45) opposite to the movable contact (29) to be received, for the pin (53) to pass through the holes (52) of the terminal fingers (45) do not provide gaps (H).

2. The clamping assembly (31, 32) according to claim 1, wherein each caliper element (60) of the clamping assembly (31, 32) formed by the two terminal finger elements (45) is movable independently relative to the other caliper elements (60) of the clamping assembly (31, 32).

3. The clamping assembly (31, 32) according to claim 1 or 2, wherein the terminal finger (45) of the clamping assembly (31, 32) is movable independently relative to the clamping element (60) of the other terminal finger (45) of the clamping assembly (31, 32).

4. The clamping assembly (31, 32) according to claim 1 or 2, wherein the support frame (46) further includes an interconnecting beam (49), and the support element (48) is mounted on the interconnecting beam.

5. The clamping assembly (31, 32) according to claim 1 or 2, further comprising bushings (54) corresponding to each hole (52) of the terminal finger element (45) and between the clamping elements (60) of the clamping assembly (31, 32).

6. The clamping assembly (31, 32) according to claim 1 or 2, further comprising a locking washer (56) for each pin (53).

7. The clamping assembly (31, 32) according to claim 1 or 2, wherein the terminal finger element (45) has a rounded tip (T) at one end corresponding to the clamping portion (50) of the corresponding caliper element (60).

8. The clamping assembly (31, 32) according to claim 1 or 2, wherein the facing profile (57) of the terminal finger element (45) of the clamp-like element (60) forms a convergence-diffusion space between the terminal finger elements (45).

9. A power switch for industrial or railway applications, comprising an insulated switch body (2) and at least one movable contact (29) providing electrical connection, characterized in that, The power switch includes at least one clamping assembly (31, 32) according to any one of claims 1 to 8, the clamping assembly being configured to clamp the at least one movable contact (29).

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