Low-voltage switch pole

Abstract

A low-voltage switch pole, comprising: an insulating housing that defines an internal space having a contact area and an arc extinguishing area; a fixed contact assembly and a movable contact assembly located in the contact area, the movable contact assembly being movable between a closed position in contact with the fixed contact assembly and an open position spaced apart from the fixed contact assembly; an arc chamber located in the arc extinguishing area, the arc chamber including a plurality of substantially parallel metal plates, characterized in that the fixed contact assembly is provided with a contact support, a contact surface that contacts the movable contact assembly in the closed position and is located on the contact support, and a conductive extension plate that is located on the contact support and extends toward the arc chamber, and is further characterized in that the fixed contact assembly is provided with a vaporization plate, and the vaporization plate is directly mounted on the conductive extension plate.

Description

Technical Field

[0001] The present invention relates to a low-voltage pole for a switching device, in particular for a low-voltage pole of a circuit breaker, disconnector or contactor used in a low-voltage electrical system (i.e., a system operating at up to approximately 1000 V alternating current). The present invention also relates to a low-voltage switch including one or more of said poles. Background Art

[0002] It is well known that low-voltage switching devices such as circuit breakers, disconnectors, contactors, limiters (hereinafter simply referred to as switches for simplicity) include one or more electrodes, with at least one pair of contacts associated with each of said electrodes, said at least one pair of contacts being capable of being connected to each other and separated from each other. Switches of the prior art also include control means that cause said pairs of contacts to move relative to each other so that they can assume at least a first connected position (circuit closed) and at least a second separated position (circuit open). The control means includes, for example, a shaft that terminates in, for example, an operable connection to said movable contact.

[0003] In particular, a circuit breaker is usually provided with a system that ensures the nominal current required by each user, the connection and disconnection of loads, the prevention of any abnormal conditions (such as overload and short circuit) by automatically opening the circuit, and the disconnection of the protected circuit (current isolation) by opening the movable contact relative to the fixed contact in order to achieve complete isolation of the load from the power supply.

[0004] In a specific part of the circuit breaker constituted by a so-called deionization arc chamber, the circuit breaker provides the key function of interrupting current (rated current, overload current or short-circuit current).

[0005] Therefore, usually at least one arc chamber is associated with each pole of the low-voltage switch, i.e., a spatial region specifically designed to facilitate arc interruption. The arc chamber can be a simple region provided in the housing of the switch, or can include various modular elements shaped, for example, like a housing made of insulating material equipped with arc-breaking plates. More advanced modular arc chambers have the advantages of being replaceable and being made of a material more suitable than, for example, the material used for the housing of the switch.

[0006] During a short circuit, the arc formed in the arc extinguishing chamber (typically composed of arc metal plates) tends to raise its temperature, so cooling means are required to control the emergency situation, especially in the case of high-range currents and voltages.

[0007] Typical solutions use gasification devices and / or materials that are capable of releasing quenching substances in the vicinity of the area where the electric arc is formed. These gasification devices and / or materials are typically triggered by the temperature reached during the occurrence of the electric arc. Such gasification devices are usually placed at various positions in the arc chamber, so the quenching effect is limited to some extent and not entirely satisfactory. Summary of the Invention

[0008] Based on the above considerations, there is a need for available alternative technical solutions that will be able to overcome the above limitations and problems. Accordingly, the present disclosure aims to provide a low-voltage switch pole that allows overcoming at least some of the above disadvantages.

[0009] In particular, the present invention aims to provide a low-voltage switch pole in which the negative effects of the electric arc generated during the current interruption operation are minimized.

[0010] Another object of the present invention is to provide a low-voltage switch pole in which more effective electric arc quenching can be ensured.

[0011] Yet another object of the present invention is to provide a low-voltage switch pole that can be easily manufactured at an industrial level and at a competitive cost compared to the prior art solutions.

[0012] To achieve these objects, the present invention provides a low-voltage switch pole comprising: an insulating housing that defines an internal space having a contact area and an arc extinguishing area; a fixed contact assembly and a movable contact assembly located in the contact area, the movable contact assembly being movable between a closed position in which it contacts the fixed contact assembly and an open position in which it is spaced apart from the fixed contact assembly; an arc chamber located in the arc extinguishing area, the arc chamber including a plurality of substantially parallel metal plates.

[0013] The low-voltage switch pole of the present invention is characterized in that the fixed contact assembly is provided with: a contact support; a contact surface located on the contact support, the contact surface contacting the movable contact assembly in the closed position; and a conductive extension plate located on the contact support, the conductive extension plate extending towards the arc chamber, and the low-voltage switch pole of the present invention is further characterized in that the fixed contact assembly is provided with a gasification plate that is directly mounted on the conductive extension plate.

[0014] In this way, the electric arc can be effectively quenched and the temperature rise caused by the arcing phenomenon can be limited.

[0015] In fact, the fixed contact of the low-voltage switch of the present invention is provided with an extension plate or a horn, and a vaporization plate is mounted on the extension plate or the horn. This vaporization plate cooperates with the arc extinguishing chamber of the low-voltage switch, so that hot gas is urged to be generated through the arc chamber, and an enhanced vaporization effect is produced, especially near the arc root (which represents the hottest area) near the fixed contact part.

[0016] Different from the conventional solution, in the low-voltage switch of the present invention, the vaporization device is directly located at the arc root, close to the fixed contact, while in the conventional solution, the vaporization device is usually placed at the side of the arc, so it is far from the arc root, which to some extent limits the quenching effect.

[0017] In fact, it has been seen that the solution of directly installing the vaporization device at the arc root brings two effects:

[0018] - Because the arc root area is the hottest area, a higher temperature causes a higher vaporization effect;

[0019] - A pressure shock effect is generated by the vaporization device at the arc root, thereby squeezing the cross-section of the arc and increasing the resistance, and thus reducing the current peak value and shortening the arc starting time.

[0020] In a preferred embodiment of the low-voltage switch pole according to the present invention, the conductive extension plate and the vaporization plate extend below the arc chamber.

[0021] The shape and size of the vaporization plate can be selected as needed. However, in another preferred embodiment of the low-voltage switch pole according to the present invention, the vaporization plate protrudes beyond the outer periphery of the conductive extension plate, that is, its overall size is larger than the overall size of the conductive extension plate on which it is mounted.

[0022] In a typical embodiment of the low-voltage switch pole according to the present invention, the vaporization plate has at least a first part, the first part is located on the conductive extension plate and protrudes beyond the outer periphery of the conductive extension plate, and the vaporization plate has a first cut part at the center of the first part, so that the central part of the conductive extension plate is left uncovered.

[0023] In a preferred embodiment of the low-voltage switch pole according to the present invention, the vaporization plate has a first part, the first part is located on the conductive extension plate and protrudes beyond the outer periphery of the conductive extension plate; the vaporization plate also has a second part surrounding the contact surface.

[0024] In another embodiment of the low-voltage switch pole according to the present invention, the vaporization plate is substantially T-shaped and has a first portion that lies on the conductive extension plate and projects beyond the outer periphery of the conductive extension plate; the vaporization plate also has a second portion that extends perpendicularly from the first portion in the direction of the contact surface.

[0025] According to this latter embodiment, in its preferred variant, the vaporization plate has: a first cutout at the center of the first portion, leaving the central portion of the conductive extension plate uncovered; and a second cutout at the center of the second portion, with at least a part of the contact surface located within the second cutout of the vaporization plate.

[0026] As mentioned above, the shape and dimensions of the vaporization plate can be selected as needed. For example, in the above embodiment, the second cutout of the second portion of the vaporization plate is preferably wider than the first cutout of the first portion of the vaporization plate.

[0027] Similarly, in such an embodiment, the first portion of the vaporization plate is preferably wider than the second portion of the vaporization plate. However, different dimensions of the various portions and cutouts of the vaporization plate can be foreseen.

[0028] In another preferred embodiment of the low-voltage switch pole according to the present invention, the conductive extension plate and the vaporization plate are provided with holding means for fixing the vaporization plate to the conductive extension plate.

[0029] For example, the holding means can advantageously include: one or more engaging pins located on one of the conductive extension plate or the vaporization plate; and corresponding one or more engaging seats for the engaging pins located on the other of the conductive extension plate or the vaporization plate. In this way, the components can be assembled very easily and quickly.

[0030] A low-voltage switch including the switch pole disclosed herein is also part of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other features and advantages of the present invention will be disclosed from the description of the preferred but non-exclusive embodiments of the low-voltage switch pole according to the present invention, and non-limiting examples of the present invention are provided in the drawings, wherein:

[0032] Figure 1 is a perspective view of an embodiment of the low-voltage switch pole according to the present invention;

[0033] Figure 2 is a perspective view of an embodiment of the fixed contact assembly in the low-voltage switch pole according to the present invention;

[0034] Figure 3It is an exploded view of an embodiment of a fixed contact assembly in a low-voltage switch pole according to the present invention. Detailed Description

[0035] Referring to the accompanying drawings, the low-voltage switch pole according to the present invention is designated by reference numeral 1. In its more general definition, the low-voltage switch pole includes an insulating housing 2 that defines an internal space. In Figure 1 the illustrated embodiment, a double-break switch pole is shown. The present invention is not intended to be limited to such double-break switching technology, but has a more general applicability.

[0036] Specifically referring to Figure 1 , in the internal space of the housing 2 of the low-voltage switch pole 1, one or more contact regions 3, 30 and corresponding one or more arc-extinguishing regions 4, 40 are provided.

[0037] The fixed contact assemblies 5, 50 and the movable contact assemblies 6, 60 are located in the corresponding contact regions 3, 30. According to known technical solutions, the movable contact assemblies 6, 60 can move between a closed position and an open position. In the closed position, the movable contact assemblies are in contact with the fixed contact assemblies 5, 50, and in the open position, the movable contact assemblies are spaced apart from the corresponding fixed contact assemblies 5, 50.

[0038] The arc chambers 41, 410 include a plurality of substantially parallel metal plates that are generally inserted into corresponding outer housings, and the arc chambers are typically positioned in the arc-extinguishing regions 4, 40.

[0039] Generally speaking, the operating principle and function of the low-voltage switch used in the present invention, as well as the related components and mechanisms, can be of a conventional type and will not be described in further detail.

[0040] Also referring to Figure 2 and Figure 3 , one of the distinguishing features of the low-voltage switch pole 1 of the present invention is given by the fact that the fixed contact assemblies 5, 50 are provided with contact supports 51, 510 on which contact surfaces 52, 520 are provided. The contact surfaces 52, 520 are in contact with the movable contact assemblies 6, 60 in the closed position of the switch pole 1 and are spaced apart from the movable contact assemblies 6, 60 in the open position of the switch pole 1.

[0041] The fixed contact assemblies 5, 50 further include conductive extension plates 53, 530 that are also located on the contact supports 51, 510 and extend towards the arc chambers 41, 410.

[0042] Another distinguishing feature of the low-voltage switch pole 1 of the present invention is that the fixed contact assemblies 5, 50 are further provided with vaporization plates 54, 540, which are directly mounted on the conductive extension plates 53, 530.

[0043] As shown in the drawings, the conductive extension plates 53, 530 and the vaporization plates 54, 540 located on the conductive extension plates extend beyond the contact areas 3, 30 and extend below the arc chambers 41, 410, so that the arc can be effectively pushed from the arc chambers 3, 30 to the arc extinguishing regions 4, 40.

[0044] In the embodiment shown in the drawings, the area covered by the vaporization plates 54, 540 is larger than the area covered by the conductive extension plates 53, 530. In fact, in this embodiment, when the vaporization plates 54, 540 are mounted on the conductive extension plates 53, 530, the vaporization plates 54, 540 protrude beyond the outer periphery of the conductive extension plates 53, 530.

[0045] In a preferred embodiment of the voltage switch pole 1 according to the present invention, the vaporization plates 54, 540 are provided with a first portion 7, which is located on the conductive extension plates 53, 530 and protrudes beyond the outer periphery of the conductive extension plates 53, 530. Then, as Figure 2 and Figure 3 shown, the vaporization plates 54, 540 have a first cutout portion 71 at the center of the first portion 7, and the first cutout portion 71 does not cover the central portion of the conductive extension plates 53, 530, thereby providing a conductive path for the arc towards the arc chamber.

[0046] In another embodiment of the low-voltage switch pole 1 according to the present invention, the vaporization plates 54, 540 are provided with a first portion 7, which is located on the conductive extension plates 53, 530 and protrudes beyond the outer periphery of the conductive extension plates 53, 530. Then, as Figure 2 and Figure 3 shown, the vaporization plates 54, 540 are further provided with a second portion 8 surrounding the contact surfaces 52, 520.

[0047] In another embodiment of the low-voltage switch pole 1 according to the present invention, the vaporization plates 54, 540 are substantially T-shaped and are provided with a first portion 7, which is located on the conductive extension plates 53, 530 and protrudes beyond the outer periphery of the conductive extension plates 53, 530. Then, referring to Figure 2 and Figure 3 , the vaporization plates 54, 540 are also conveniently provided with a second portion 8, which extends perpendicularly from the first portion 7 in the direction of the contact surfaces 52, 520, that is, opposite to the arc extinguishing regions 4, 40.

[0048] In a further embodiment of the low - voltage switch pole 1 of the present invention, the vaporization plates 54, 540 conveniently have a first cut - out portion 71 at the center of the first part 7, and this first cut - out portion 71 does not cover the central portion of the conductive expansion plates 53, 530, thereby providing a conduction path for the arc towards the arc chamber. Then, the vaporization plates 54, 540 also have a second cut - out portion 81 at the center of the second part 8, thereby providing a rigid structure (seta) for the contact surfaces 52, 520, and the contact surfaces 52, 520 are at least partially located within the second cut - out portion 81.

[0049] In the embodiment of the low - voltage switch pole 1 shown in the drawings, the second cut - out portion 81 of the second part 8 of the vaporization plates 54, 540 is wider than the first cut - out portion 71 of the first part 7 of the vaporization plates 54, 540.

[0050] Similarly, in such an embodiment, the first part 7 of the vaporization plates 54, 540 is wider than the second part 8 of the vaporization plates 54, 540. Different choices of the shape and size of the vaporization plates 54, 540 and different choices of the shape and size of the conductive expansion plates 53, 530 can also be made according to the operating requirements and design of the low - voltage switch.

[0051] In a typical embodiment of the low - voltage switch pole 1 according to the present invention, the conductive expansion plates 53, 530 and / or the vaporization plates 54, 540 can be provided with suitable holding means for fixing the vaporization plates 54, 540 to the conductive expansion plates 53, 530.

[0052] For example, referring to the drawings, the low - voltage switch pole 1 according to the present invention can be provided with holding means, which includes one or more engagement pins 91. The engagement pins 91 are, for example, positioned on the conductive expansion plates 53, 530 and have corresponding one or more engagement seats 92 for the pins 91, and the engagement seats 92 are, for example, positioned on the vaporization plates 54, 540.

[0053] Another layout can also be adopted, that is, positioning the pins 91 on the vaporization plates 54, 540 and positioning the corresponding one or more engagement seats 92 for the pins 91 on the conductive expansion plates 53, 530; other fixing means can also be used.

[0054] It is clear from the above that the low - voltage switch pole 1 of the present invention allows the solution of the problems emphasized above. In fact, due to the proper layout of the contact area and the arc - extinguishing area, and especially due to the proper positioning of the vaporization plate, the low - voltage switch pole 1 of the present invention improves the vaporization effect and the arc - quenching effect compared with more traditional solutions of switches in the prior art.

[0055] Furthermore, from a mechanical point of view, the low-voltage switching pole 1 is very simple and requires a limited number of components, thus not negatively affecting the overall cost of the circuit breaker.

[0056] Several variants can be made to the low-voltage switching pole 1 and to the low-voltage switch including such low-voltage switching poles thus conceived, all of which variants fall within the scope of the appended claims. In fact, depending on the requirements and the state of the art, the materials used as well as the possible dimensions and shapes can be arbitrary.

Claims

1. A low-voltage switch pole (1), comprising: Insulating housing (2), the insulating housing defining an internal space having a contact region (3, 30) and an arc extinguishing region (4, 40); A fixed contact assembly (5, 50) and a movable contact assembly (6, 60) located in the contact region (3, 30), the movable contact assembly (6, 60) being movable between a closed position and an open position, in the closed position, the movable contact assembly is in contact with the fixed contact assembly (5, 50), and in the open position, the movable contact assembly is spaced apart from the fixed contact assembly (5, 50); An arc chamber (41, 410) located in the arc extinguishing region (4, 40), the arc chamber including a plurality of parallel metal plates, characterized in that the fixed contact assembly (5, 50) is provided with: a contact support (51, 510); a contact surface (52, 520) in contact with the movable contact assembly (6, 60) in the closed position, the contact surface being located on the contact support (51, 510); and a conductive extension plate (53, 530) located on the contact support (51, 510), the conductive extension plate extending towards the arc chamber (41, 410), and the fixed contact assembly (5, 50) is further provided with a vaporization plate (54, 540), the vaporization plate being directly mounted on the conductive extension plate (53, 530), wherein the vaporization plate (54, 540) is T-shaped and has a first portion (7) located on the conductive extension plate (53, 530) and protruding beyond the outer periphery of the conductive extension plate (53, 530) and a second portion (8) surrounding the contact surface (52, 520), the second portion extending perpendicularly from the first portion (7) in a direction towards the contact surface (52, 520).

2. The low-voltage switch pole (1) according to claim 1, characterized in that, The conductive extension plate (53, 530) and the vaporization plate (54, 540) extend beyond the contact region (3, 30) and extend below the arc chamber (41, 410).

3. The low-voltage switch pole (1) according to claim 1 or 2, characterized in that, The vaporization plate (54, 540) protrudes beyond the outer periphery of the conductive extension plate (53, 530).

4. The low-voltage switch pole (1) according to claim 1 or 2, characterized in that, The vaporization plate (54, 540) has a first cutout portion (71) located at the center of the first portion (7), leaving the central portion of the conductive extension plate (53, 530) uncovered.

5. The low-voltage switch pole (1) according to claim 1, characterized in that, The vaporization plate (54, 540) has a first cutout portion (71) located at the center of the first portion (7), leaving the central portion of the conductive extension plate (53, 530) uncovered, and the vaporization plate further has a second cutout portion (81) located at the center of the second portion (8), and the contact surface (52, 520) is at least partially located within the second cutout portion (81).

6. The low-voltage switch pole (1) according to claim 5, characterized in that, The second cutout portion (81) of the second portion (8) of the vaporization plate (54, 540) is wider than the first cutout portion (71) of the first portion (7) of the vaporization plate (54, 540).

7. The low-voltage switch pole (1) according to claim 5 or 6, characterized in that, The first part (7) of the gasification plate (54, 540) is wider than the second part (8) of the gasification plate (54, 540).

8. The low-voltage switch pole (1) according to claim 1 or 2, characterized in that, The conductive extension plate (53, 530) and the gasification plate (54, 540) are provided with holding means for fixing the gasification plate (54, 540) to the conductive extension plate (53, 530).

9. The low-voltage switch pole (1) according to claim 8, characterized in that, The holding means includes one or more engagement pins (91) and corresponding one or more engagement seats (92) for the engagement pins (91), the engagement pins being located on one of the conductive extension plate (53, 530) or the gasification plate (54, 540), and the engagement seats being located on the other of the conductive extension plate (53, 530) or the gasification plate (54, 540).

10. A low-voltage switch, comprising a low-voltage switch pole (1) according to any one of claims 1 to 9.

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