Switch, multipole switch, and method of operating switch to switch on and off current

Abstract

The invention relates to a switch, a multipole switch and a method for operating a switch for switching on and off a current. The switch can bear short-circuit current and cannot be damaged or degraded due to passing of large current. The invention relates to a switch comprising at least one fixed contact and at least one movable contact, the movable contact being displaceable between a closed position of the switch, in which the fixed contact and the movable contact are electrically connected, and an open position of the switch, in which the fixed contact and the movable contact are separated. The switch comprises at least one equipotential connection member electrically connecting the fixed contact and the movable contact in the closed position of the switch such that the fixed contact and the movable contact are at the same potential, and wherein in the closed position of the switch, the fixed contact and the movable contact are electrically connected to each other. At least a portion of the equipotential connection member is pressed against the fixed contact and / or the movable contact.

Description

Technical Field

[0001] The present invention generally relates to power switches particularly suitable for withstanding short circuit currents.

[0002] An object of the present invention is to provide a switch that can withstand a short-circuit current and will not be destroyed or degraded by the passage of such a high current.

[0003] More specifically, an object of the present invention is to provide a switch of the above-mentioned type which can be manufactured with reduced material and reduced costs and which can be easily retrofitted into existing switch designs.

[0004] The invention also relates to a method for operating a switch of the above-mentioned type for switching an electric current on and off. Background Art

[0005] The permissible short-time withstand current (Icw) characterizes the ability of a device to withstand a short-circuit current, which is usually very large, for a duration sufficient to eliminate the short-circuit current with the help of a circuit breaker or protective device located downstream of the device.

[0006] Therefore, this is an essential feature of a circuit breaker or disconnect switch located at the top of an electrical device.

[0007] The higher the value of Icw that the circuit breaker is subjected to, the higher the limit of utilization of the timing selectivity.

[0008] It must be remembered that both the switchboard where the circuit breaker is installed and all conductors upstream must be able to withstand these currents.

[0009] Short-circuit current produces the following two types of phenomena in the switch:

[0010] -i) Short-circuit currents generate electrodynamic stresses between the different parts of the circuit through which the current circulates. Repulsive or attractive forces are generated, depending on the respective direction of the current; these forces manifest themselves instantaneously, and the resistance of the device to these forces - called the "electrodynamic resistance" (TDE) - will be characterized by the maximum instantaneous value of the current that the device can withstand, measured in "peak" kiloamperes (KAmpers). Exceeding this value, irreversible deformation of the part or arcing will occur, which may damage the part in question.

[0011] -ii) Heating of the part through which the current circulates. This heating does not depend on the instantaneous value of the current, but on its effective value and its duration; therefore, the resistance of the switch / disconnector to these phenomena can be expressed in effective kiloamperes and seconds. This heating can often lead to the welding of the moving contacts to the fixed contacts, which means that the disconnector cannot switch to the open position and no longer fulfils its main function of opening and breaking connections to electrically isolate the circuit.

[0012] The "allowable short-time withstand current" is defined in a number of standards including IEC 60947-2, which give it the symbol Icw.

[0013] The associated test makes it possible to test the behaviour of the disconnector in the event of a short circuit, both electrically and thermally, by maintaining the current for a given time (usually 0.5 s, 1 s or 3 s).

[0014] The maximum peak current is defined by the standard as a function of the effective current; knowledge of the effective current is sufficient to define Icw.

[0015] It is obvious that the Icw value of a circuit breaker is limited by the most severe phenomenon, whether electromechanical or thermal, and therefore this value generally decreases as its duration increases: an Icw lasting 3 seconds is 9 times worse thermally than an Icw lasting 1 second.

[0016] At the initial moment of a short circuit, when the current starts to flow through the fixed contacts and is distributed on the moving contacts, the electrodynamic repulsive force Fr may sometimes be much greater than the force applied by the contact pressure spring Fp.

[0017] At this moment, the moving contact may float, which can temporarily lead to a loss of contact pressure or even to disconnection of the connection.

[0018] In the event of a loss of contact pressure, the contact resistance increases, which leads to strong heating in this area, resulting in melting and welding of the material constituting the electrical connection, which subsequently prevents the circuit breaker from opening when the electrical connection is strongly welded.

[0019] In the case of contact separation, an arc occurs, which may also cause strong welding between the fixed contact and the moving contact, so that the circuit breaker cannot open. Occasionally, in the case of repulsion forces that are much greater than the contact pressure, the contacts separate due to the repulsion forces, resulting in a strong arc, which can generate a large internal overpressure. This internal overpressure usually causes the circuit breaker to explode.

[0020] This separation of the contacts will result in a loss of equipotential at the connection portion of the fixed contact and the moving contact. This equipotential loss of the connection portion will cause the potential difference Va-Vb between the connection area of ​​the fixed contact and the connection area of ​​the moving contact to reach a value equal to the maximum voltage of the circuit (380Vac, 400Vac), which will generate an arc, the intensity of which is the value of Icw at that moment, and the energy released will cause the circuit breaker to catch fire or explode, thereby causing serious damage to equipment and even to personnel.

[0021] Figure 1AA conventional switch 1 is shown which is formed by two fixed contacts 3a, 3b and a movable contact 4, the movable contact 4 being formed by two blades 4a, 4b which overlap and contact the two fixed contacts 3a, 3b in the closed position of the switch. The switch 1 comprises two pressure springs 2, 2' which apply a force Fp to press the two blades 4a, 4b towards the fixed contacts 3a, 3b. When a short circuit occurs, the short circuit current I entering the switch through the fixed contact 3a will be divided into two currents I / 2 through each of the blades 4a, 4b, as shown by Figure 1A These currents generate a repulsive force Fr in the direction opposite to the force Fp of the pressure springs 2, 2', and in the case of a high repulsive force, the blades 4a, 4b will float and the equipotential between the blades 4a, 4b and the fixed contact 3a will be interrupted ( Figure 1B ).

[0022] Figure 2A The voltage Va-Vb shown in will produce an arc, such as Figure 1B and Figure 2C As shown in FIG. 1 , the arc may generate welding points 5a, 5b between the sheet members 4a, 4b and the fixed contact 3a, as shown in FIG. Figure 2B as shown in .

[0023] In order to try to minimize these problems to some extent, current prior art solutions use stronger contact pressure springs to apply greater force and reduce the contact separation problem caused by the strong repulsive force. In this way, manufacturers try to increase the resistance to a higher Icw. U.S. Patent Publication US2014 / 0353136 A1 describes an example of such prior art solutions.

[0024] Using stronger springs to increase the force to hold the fixed contacts makes the kinematics of opening and closing the circuit breaker more difficult and requires more manipulation, which requires greater structural requirements on the circuit breaker to increase the robustness of the circuit breaker, which in turn increases the thickness of the thermoplastic material, copper, steel, and also increases the size of the circuit breaker, resulting in the use of more raw materials and resulting in a heavier weight of the raw materials, and therefore resulting in a greater environmental impact and more cost.

[0025] Therefore, providing a power switch that overcomes the above-mentioned shortcomings of the current technology remains a challenge in the art. Summary of the invention

[0026] The present invention is defined in its main aspects and satisfactorily solves the above-mentioned shortcomings of the prior art by providing a switch that is capable of withstanding a short-circuit current and maintaining its integrity, i.e., not being damaged or destroyed, at least for a sufficient time to allow other protection devices connected downstream to open the circuit and interrupt the short-circuit current.

[0027] Therefore, a first aspect of the present invention relates to a switch comprising: at least one fixed contact and at least one movable contact, wherein the movable contact is capable of shifting between a closed position of the switch and an open position of the switch, in which the fixed contact and the movable contact are electrically connected so that current can circulate through the fixed contact and the movable contact, and in the open position of the switch, the fixed contact and the movable contact are spaced apart from each other so that the circulation of current through the fixed contact and the movable contact is hindered.

[0028] According to the invention, the switch further comprises at least one equipotential connection member, which electrically connects the fixed contact and the movable contact in the closed position of the switch. In addition, a part of the equipotential connection member is configured to press against the fixed contact and / or the movable contact in the closed position of the switch.

[0029] The equipotential connection member is constructed and arranged in the switch to ensure that the fixed contact and the movable contact remain connected in the closed position of the switch - even when the fixed contact and the movable contact are separated due to repulsive forces caused by the short-circuit current flowing through the switch - so that the fixed contact and the movable contact remain at the same potential during a short-circuit event, thereby preventing the formation of an arc between the two contacts.

[0030] For this purpose, the equipotential connection member is configured to hold the fixed contact and the movable contact pressed together in the closed position of the switch, thereby ensuring that the fixed contact and the movable contact remain at the same potential even when the fixed contact and the movable contact are separated due to the repulsive force caused by the short-circuit current.

[0031] In a preferred embodiment, the equipotential connection member is configured as a clamp or clip, which surrounds the fixed contact or the movable contact or both the fixed contact and the movable contact in the closed position of the switch, in particular, the equipotential connection member surrounds the fixed contact and / or the movable contact at the portion of the contact that overlaps and contacts in the closed position. In this position, a part of the equipotential connection member is placed above the fixed contact or the movable contact or both the fixed contact and the movable contact, so that when the fixed contact and the movable contact are separated due to a short-circuit current, the fixed contact and the movable contact will remain connected by the equipotential connection member, thereby ensuring that the two contacts are at the same potential.

[0032] Due to the equipotential connection member, even when the fixed contact and the movable contact are separated in the closed position of the switch, it is ensured that the potential difference between the fixed contact and the movable contact is always zero, so that no arc can be formed between the two contacts. Therefore, the switch is not affected by the destructive effects of an arc between the contacts.

[0033] The present invention focuses on increasing the limit of Icw by overcoming the severe electromechanical effects of high short circuit currents and eliminating the influence of contact repulsion forces at the initial moment of short circuit.

[0034] Obviously, the equipotential connection member is arranged and constructed such that in the open position of the switch, the equipotential connection member is disconnected from the fixed contact or the movable contact or from both the fixed contact and the movable contact.

[0035] In the closed position of the switch, the fixed contact and the movable contact overlap and contact at a contact surface, and a portion of the equipotential connection member that presses against the fixed contact and / or the movable contact is pressed in a direction toward the contact surface.

[0036] In a preferred embodiment of the invention, the portion of the equipotential connecting member that presses against the fixed contact and / or the movable contact is realized as a flexible metal plate, which is configured to exert pressure on the fixed contact and / or the movable contact due to its flexible properties in the closed position of the switch.

[0037] Preferably, the equipotential connection member is configured such that a portion of the equipotential connection member is permanently attached to the fixed contact, and in the closed position of the switch, the portion of the equipotential connection member configured as a flexible metal plate overlaps the movable contact and presses the movable contact toward the fixed contact to ensure that the fixed contact and the movable contact remain connected.

[0038] In this way, in case the movable contact is separated from the fixed contact in the closed position of the switch, the displacement of the movable contact will deflect the equipotential connection member which will remain connected to the movable contact.

[0039] In a preferred embodiment of the invention that can be combined with other embodiments, the fixed contact is a substantially flat and elongated body, each of which is formed by a rigid metal piece. Preferably, the switch comprises a first fixed contact and a second fixed contact spaced apart from each other, and the movable contact is placed in the space between the first fixed contact and the second fixed contact in the closed position of the switch, and the movable contact is electrically connected to the two fixed contacts. The movable contact consists of two sheet-like members, which are implemented as substantially flat and elongated bodies, each of which is formed by a rigid metal piece, wherein the two sheet-like members are spaced apart from each other and parallel.

[0040] Furthermore, the switch comprises a first equipotential connection member and a second equipotential connection member, which connect the movable contact with the first and second fixed contacts respectively in the closed position of the switch.

[0041] In a preferred embodiment of the present invention which can be combined with other embodiments, the first fixed contact and the second fixed contact are aligned in a first direction, and the movable contact is linearly displaceable in a second direction orthogonal to the first direction.

[0042] Another aspect of the present invention relates to a multi-pole switch, comprising an array of switches that are opened and closed simultaneously, wherein each switch is a pole of the multi-pole switch and each switch is a switch described in any of the previous embodiments. Conventionally, the multi-pole switch comprises a carrier made of an electrically insulating material, and all movable contacts of the switch are mounted in the carrier so that all movable contacts move simultaneously between the open position and the closed position of the multi-pole switch.

[0043] Another aspect of the present invention relates to a method for operating a switch for switching on and off an electric current. The method comprises the steps of maintaining the fixed contact and the movable contact of the switch at the same potential in the closed position of the switch when the fixed contact of the switch is electrically connected to the movable contact and a short circuit current circulates through the switch. Preferably, the switch is a switch in any of the embodiments described above.

[0044] The fixed contact and the movable contact of the switch are kept at the same potential in the closed position of the switch by clamping and pressing the fixed contact and the movable contact together with the help of an equipotential connection member made of a flexible metal sheet. The equipotential connection member surrounds and presses the fixed contact and the movable contact together at the overlapping and contacting parts of these contacts. In this way, in the event that the fixed contact and the movable contact are separated due to the circulation of a short-circuit current through these contacts, the equipotential connection member remains connected to the fixed contact and the movable contact, thereby ensuring that the two contacts are at the same potential.

[0045] Preferably, the switch of the present invention is suitable for operating as a circuit breaker, which can be advantageously used as a head circuit breaker, which is installed at the head of a circuit, such as a distribution board, so that it can withstand a large short-circuit current without being damaged, thereby providing sufficient time for other protective devices connected downstream to react to the short circuit and disconnect the corresponding part of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to complete the description and to provide a better understanding of the present invention, a set of drawings is provided. These drawings constitute an integral part of the present description and illustrate various embodiments of the present invention, which should not be interpreted as limiting the scope of the present invention, but only as examples of how the present invention can be implemented. These drawings include the following figures:

[0047] Figure 1A , Figure 1B -exist Figure 1A , showing a top elevation view of a prior art power switch incorporating a leaf spring member to press a movable contact against a fixed contact, wherein arrows represent repulsive forces and current circulating through the contacts; and Figure 1B is an electrical diagram illustrating contact suspension during a short circuit resulting in arcing.

[0048] Figure 2A , Figure 2B , Figure 2C -exist Figure 2A A perspective view of a prior art switch is shown in , wherein arrows indicate the current distribution and circulation through the contacts. Figure 2B and Figure 2C is an electrical diagram illustrating contact suspension and current distribution during a short circuit resulting in an arc.

[0049] Figure 3A , Figure 3B -exist Figure 3A 1 shows a perspective view of an exemplary embodiment of a switch according to the invention, which is in the open position. Figure 3B yes Figure 3A Electrical diagram of the switch.

[0050] Figure 4A , Figure 4B —shows the Figure 3A , Figure 3B A similar diagram but with the switch in the closed position and the rated current circulating through the switch.

[0051] Figure 5A , Figure 5B —shows the Figure 4A , Figure 4B A similar diagram but with a short circuit current circulating through the switch.

[0052] Fig. 6A , Figure 6B , Figure 6C , Fig.6D -exist Fig. 6A A perspective view of the switch in the previous figures is shown in FIG. Figure 6B and Figure 6C yes Fig. 6A The enlarged details, especially Figure 6B An equipotential connection member attached to a fixed contact is shown, and Figure 6C A separate equipotential bonding component is shown. Fig.6D is Fig. 6A Cross-sectional view taken at the AA plane in FIG.

[0053] Fig. 7A , Figure 7B , Figure 7C , Fig. 8A , Figure 8B , Figure 8C as well as Fig.9A , Fig. 9B , Fig. 9C , Fig.9D —shows the Fig. 6A , Figure 6B , Figure 6C , Fig.6D Similar illustrations but with other configurations of equipotential bonding components.

[0054] Fig.10 —shows a device including a pressing member Fig.9A , Fig. 9B , Fig. 9C , Fig.9D A perspective view of the switch. DETAILED DESCRIPTION

[0055] Figure 3A , Figure 3B , Figure 4A and Figure 4B A preferred embodiment of a switch 1 according to the invention is shown, the switch 1 conventionally comprising a first fixed contact 3a and a second fixed contact 3b formed by a substantially flat and elongated body, each formed by a rigid metal piece, and aligned in a first direction X.

[0056] The switch 1 further comprises a movable contact 4 consisting of two blades 4a, 4b, which are also implemented as a substantially flat and elongated body, each formed of a rigid metal piece. The blades 4a, 4b are spaced apart and parallel to each other. In the disconnected position ( Figure 3A ) and closed position ( Figure 4A ), the movable contact 4 moves along a direction Y substantially orthogonal to the direction X.

[0057] The spacing distance between the sheet-like members 4a, 4b roughly matches the thickness of the fixed contacts 3a, 3b, so that in the closed position of the switch ( Figure 4A), two sheet members overlap and contact the fixed contacts, one sheet member 4b contacts the lower side of the fixed contact, and the other sheet member 4a contacts the upper side of the fixed contact. In the closed position of the switch, the movable contact 4 is placed in the space between the first fixed contact 3a and the second fixed contact 3b, so the movable contact 4 is aligned with the fixed contacts 3a, 3b.

[0058] like Figure 4A As shown in FIG. 1 , in the closed position, the rated current I circulating through the fixed contacts 3 a , 3 b will be divided into two currents I / 2 while circulating through the two blades 4 a , 4 b .

[0059] According to the present invention, the switch 1 is combined with two equipotential connection members, namely: a first equipotential connection member 6a, which electrically connects the first fixed contact 3a with the two sheet members 4a, 4b at one end of the sheet members in the closed position of the switch 1; and a second equipotential connection member 6b, which electrically connects the second fixed contact 3b with the two sheet members 4a, 4b at the other end of the sheet members. Figure 3A and Figure 4A In addition, the two equipotential connection members 6a, 6b are configured to keep the fixed contact and the movable contact pressed together in the closed position of the switch, so as to ensure that the fixed contact and the movable contact remain at the same potential even if they are separated due to the repulsive force caused by the short-circuit current. In this way, and as Figure 4A As shown in , the voltage Va at the first fixed contact 3a, the voltage Vb at the upper sheet 4a, and the voltage Vc at the first equipotential connecting member are the same.

[0060] It should be noted that the two equipotential connection members 6a, 6b are configured to hold the fixed contact and the movable contact pressed together, but they are not like Figure 1A The movable contact 2 is not used as a pressing member like the pressing members 2, 2' of FIG. 1 , but is used to ensure electrical connection between the fixed contact and the movable contact while the movable contact is suspended from the fixed contact.

[0061] In the preferred embodiment shown in the accompanying drawings, each of the equipotential connecting members 6a, 6b is permanently attached to the fixed contacts 3a, 3b, and each of the equipotential connecting members 6a, 6b is configured to be in contact with the blades 4a, 4b in the closed position of the switch. To this end, a portion of each equipotential connecting member 6a, 6b is a flexible metal plate that overlaps one of the blades 4a, 4b and presses one of the blades 4a, 4b against the fixed contact in the closed position of the switch. Due to this configuration of the equipotential connecting members 6a, 6b, when a short circuit cycles through the switch and the blades 4a, 4b and the fixed contacts 3a, 3b are separated by repulsive forces, the blades 4a, 4b and the fixed contacts 3a, 3b will remain electrically connected with the aid of the equipotential connecting members 6a, 6b, so that the fixed contacts and the blades of the movable contact remain at the same potential, as shown in FIG. Figure 5B as shown in .

[0062] In other preferred embodiments, the equipotential connecting members 6 a, 6 b are attached to the blades 4 a, 4 b and are pressed against the fixed contacts 3 a, 3 b in the closed position of the switch 1 .

[0063] It should be understood that the operating principles of the present invention may be applied to other types of switches than those shown in the described figures.

[0064] FIG. 6A to FIG. 6D The preferred configuration of the equipotential connection members 6a, 6b is more clearly shown. Each equipotential connection member 6a, 6b is implemented as a metal plate shaped as a clamp, which in the closed position of the switch surrounds the fixed contact and the movable contact at their overlapping portion.

[0065] The equipotential connection members 6a, 6b press the blade and the fixed contact together in the closed position of the switch. Each equipotential connection member 6a, 6b has a central portion 8 having a U-shaped configuration in a cross-sectional view and a first lug 9 and a second lug 9' protruding in opposite directions from the central portion 8. Figure 6B As better shown in FIG. 1 , the central portion 8 is configured and dimensioned so that the fixed contacts 3a, 3b can be tightly received inside the central portion 8, so that each member 6a, 6b is attached to the edge of the fixed contacts 3a, 3b by means of the respective central portion 8. For this purpose, the central portion 8 has wing-shaped portions 8a, 8b which are shaped with anchoring portions 10 that engage with the respective fixed contacts 3a, 3b.

[0066] Each tab 9 , 9 ′ has a first section coplanar with the central portion 8 and a second section folded relative to the first section.

[0067] exist FIG. 6A to FIG. 6DIn the embodiment of the invention, the second section of each tab 9, 9' is inclined relative to the plane defined by the blades 4a, 4b, and these inclined portions 11, 11' are flexible portions which, in the closed position of the switch, flex due to their contact with the blades 4a, 4b, as for example in Fig.6D The inclined portions 11, 11' are offset relative to the central member 8. In this way, the inclined portions 11, 11' press against the blades 4a, 4b of the movable contact and exert pressure on these blades due to their flexible properties.

[0068] In addition, Fig.6D As shown in FIG. 1 , the inclined portion 11 , 11 ′ of each member 6 a, 6 b is disposed toward the contact surface (defined by Fig.6D In addition, the inclined portions 11, 11' extend above the sheet-like members 4a, 4b.

[0069] If you can Fig.6D It is understood that under the above-mentioned configuration and arrangement of the equipotential connecting members 6a, 6b, even if the sheet members 4a, 4b are lifted off from one of the fixed contacts 3, 3' due to a larger current entering one of the fixed contacts 3, 3', the sheet members 4a, 4b will remain connected to the corresponding equipotential connecting members 6a, 6b, thereby maintaining the same potential as the fixed contacts.

[0070] 7A to 7C An alternative configuration of the equipotential connection members 6a, 6b is shown, which is similar to the above description of Fig. 6A The components described have the same parts, that is, they also have a central part 8 with wing-shaped parts 8a, 8b, both provided with anchoring parts 10, and first and second lugs 9, 9' protruding from the central part 8 in opposite directions. However, in this embodiment, the first and second lugs 9, 9' are configured as L-shaped flexible parts 11, 11', which are deflected by their contact with the flanges 4a, 4b in the closed position of the switch 1 so that these parts 11, 11' are pressed against the fixed contacts and placed above the flanges 4a, 4b. The two arms of the L-shaped part are arranged to form an angle in the range of 85° to 90°.

[0071] exist FIG. 8A to FIG. 8C In an alternative embodiment, the equipotential connection members 6a, 6b are formed as double-walled bodies, that is, each member has a first wall and a second wall, the second wall having a similar configuration to the first wall and overlapping and contacting the first wall. This configuration of the equipotential connection members 6a, 6b is a reinforced form of the equipotential connection members 6a, 6b, which can withstand higher repulsive forces. In particular, in FIG. 8A to FIG. 8CIn the case of each equipotential connection member 6a, 6b, a first U-shaped wall 12a and a second U-shaped wall 12b overlap and contact the first U-shaped wall 12a are provided. The two walls 12a, 12b have overlapping through holes 13 so that the walls 12a, 12b are attached to the fixed contacts 3a, 3b by means of rivets 14.

[0072] exist 9A to 9D In an alternative embodiment, each of the equipotential connection members 6a, 6b has an attachment portion 15a, 15b and a clamping portion 16a, 16b, both of which are connected by a central portion 17a, 17b. The attachment portion 15a, 15b is U-shaped and is suitable for being permanently attached to the fixed contacts 3a, 3b, for example, by means of a hole 13 and a rivet 14. The clamping portion 16a, 16b has two lugs protruding in opposite directions from the central portion 17a, 17b, wherein each lug has a folding line 18a, 18b forming two inclined sections. Preferably, each of the equipotential connection members 6a, 6b is also formed as a double-walled body having a first wall 12a and a second wall 12b, wherein the second wall 12b replicates the shape of the first wall 12a, and the second wall 12b overlaps and contacts the first wall 12a.

[0073] As can be understood from the above embodiments and the accompanying drawings, the equipotential connection members 6a, 6b can be easily installed during the manufacturing process of the switch without modifying the existing design of the switch components, that is, the present invention can be easily retrofitted into the existing assembly manufacturing process of the above-mentioned type of switch.

[0074] like Fig.10 As shown in FIG. 1 , the switch 1 of the present invention may be provided with conventional pressing members 2 , 2 ′ in the form of leaf springs in addition to the equipotential connection members 6 a , 6 b .

[0075] Based on any of the previously described embodiments, a multi-pole switch can be formed by arranging several switches 1 in parallel with each other and having all movable contacts 4 mounted on a common carrier (not shown) to move simultaneously.

[0076] The method of the present invention is described in any of the previously described embodiments of the present invention, wherein the method involves maintaining the fixed contacts and movable contacts of a switch at the same potential in the closed position of the switch by clamping and pressing the fixed contacts and movable contacts together by means of an equipotential connection member made of a flexible metal sheet.

Claims

1. A switch (1), comprising: At least one fixed contact (3a, 3b) and at least one movable contact (4), wherein the movable contact (4) is displaceable between a closed position of the switch and an open position of the switch, in which the fixed contacts (3a, 3b) and the movable contact (4) are in electrical contact, and in which the fixed contacts (3a, 3b) and the movable contact (4) are separated, characterized in that: The switch (1) further comprises at least one equipotential connection member (6a, 6b), which electrically connects the fixed contact (3a, 3b) and the movable contact (4) in the closed position of the switch (1), and wherein at least one portion (9, 9', 11, 11') of the equipotential connection member (6a, 6b) presses against the fixed contact (3a, 3b) and / or the movable contact (4) in the closed position of the switch to keep the fixed contact (3a, 3b) and the movable contact (4) at the same potential.

2. The switch (1) according to claim 1, wherein: In the closed position of the switch, a portion of the fixed contact (3a, 3b) and a portion of the movable contact (4) overlap and contact at a contact surface between the fixed contact (3a, 3b) and the movable contact (4), and wherein the equipotential connection member (6a, 6b) is constructed as a clamp or a clip, which surrounds the fixed contact (3a, 3b) or the movable contact (4) or both the fixed contact (3a, 3b) and the movable contact (4) at the overlapping portion of the fixed contact and the movable contact.

3. The switch (1) according to claim 1 or 2, wherein: In the closed position of the switch, the fixed contacts (3a, 3b) and the movable contact (4) overlap and contact at a contact surface, and wherein the portions (11, 11') of the equipotential connection members (6a, 6b) that press against the fixed contacts and the movable contact are pressed in a direction toward the contact surface.

4. The switch (1) according to any one of the preceding claims, wherein: The portion (11, 11') of the equipotential connection member (6a, 6b) pressed against the fixed contact (3a, 3b) and the movable contact (4) is a flexible metal plate, which is configured to apply pressure to the fixed contact and / or the movable contact in the closed position of the switch due to the flexible characteristics of the flexible metal plate.

5. The switch (1) according to any one of the preceding claims, wherein: The portion (8) of the equipotential connection member (6a, 6b) is permanently attached to the fixed contact (3a, 3b), and the portion (11, 11') configured as a flexible metal plate is placed on the movable contact (4) in the closed position of the switch and presses the movable contact (4) towards the fixed contact (3a, 3b).

6. The switch (1) according to any one of the preceding claims, wherein: The equipotential connection member (6a, 6b) is formed as a double-walled body having a first wall (12a) and a second wall (12b), the second wall (12b) having a similar configuration to the first wall (12a), wherein the two walls overlap and contact.

7. The switch (1) according to any one of the preceding claims, wherein: The movable contact (4) is composed of two sheet-like members (4a, 4b) which are implemented as substantially flat and elongated bodies, each body being formed of a rigid metal piece, wherein the sheet-like members (4a, 4b) are spaced apart from each other and are parallel.

8. A switch (1) according to any one of the preceding claims, comprising a first fixed contact (3a) and a second fixed contact (3b), the first fixed contact (3a) and the second fixed contact (3b) being formed by a substantially flat and elongated body, each body being made of a rigid metal piece, wherein The first fixed contact (3a) and the second fixed contact (3b) are aligned along a first direction (X), and wherein the movable contact (4) is linearly displaceable along a second direction (Y) orthogonal to the first direction (X).

9. The switch (1) according to claim 8, wherein: The first fixed contact (3a) and the second fixed contact (3b) are spaced apart from each other, and wherein, in the closed position of the switch, the movable contact (4) is placed in the space between the first fixed contact (3a) and the second fixed contact (3b), and the movable contact (4) is electrically connected to the two fixed contacts (3a, 3b), and wherein the switch (1) further comprises a first equipotential connecting member (6a) and a second equipotential connecting member (6b), and in the closed position of the switch, the first equipotential connecting member (6a) connects the movable contact (4) to the first fixed contact (3a), and the second equipotential connecting member (6b) connects the movable contact (4) to the second fixed contact (3b).

10. The switch (1) according to any one of the preceding claims, wherein Each equipotential connection member (6a, 6b) comprises a central portion (8) having a U-shape, wherein the central portion (8) is configured and dimensioned so that the fixed contact (3a, 3b) can be tightly received inside so that each member (6a, 6b) is attached to the edge of the fixed contact (3a, 3b) by means of the respective central portion (8), and wherein each equipotential connection member (6a, 6b) has a first lug (9) and a second lug (9') protruding in opposite directions from the central portion (8), and wherein each of the first lug (9) and the second lug (9') has a portion inclined relative to a plane defined by the sheet-like members (4a, 4b), and these inclined portions (11, 11') are flexible portions that flex in the closed position of the switch due to the contact of the inclined portions (11, 11') with the sheet-like members (4a, 4b).

11. The switch (1) according to claim 10, wherein: Each tab (9, 9') has a first section coplanar with the central portion (8) and a second section folded over relative to the first section of the tab (9, 9').

12. The switch (1) according to any one of claims 1 to 9, wherein: Each of the equipotential connection members (6a, 6b) has an attachment portion (15a, 15b) and a clamping portion (16a, 16b), both of which are connected by a central portion (17a, 17b), wherein the attachment portion (15a, 15b) is U-shaped and the attachment portion (15a, 15b) is suitable for being permanently attached to a fixed contact (3a, 3b), and wherein the clamping portion (16a, 16b) has two tabs protruding from the central portion (17a, 17b) in opposite directions, wherein each tab has a folding line (18a, 18b) forming two inclined sections.

13. A multi-pole switch comprising an array of switches that are opened and closed simultaneously, wherein: Each switch is a switch according to any one of claims 7 to 12.

14. A method for operating a switch to switch an electric current on and off, the method comprising the steps of maintaining a fixed contact and a movable contact of the switch at the same potential in a closed position of the switch while a short circuit current circulates through the switch.

15. The method according to claim 14, wherein: In the closed position of the switch, the fixed contact and the movable contact are maintained at the same potential by clamping and pressing the fixed contact and the movable contact together by means of an equipotential connection member made of a flexible metal plate.

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