Switch and change-over switch with a compact structure

Abstract

The present invention relates to a switch (1), which comprises a switch body (2) adapted to accommodate switch components, at least two terminal contacts (34, 40) extending from the switch body, and at least one movable contact (29) capable of moving between an operating position and an open position. In the operating position, the movable contact is electrically connected between the at least two terminal contacts, and in the open position, the movable contact is electrically disconnected between the at least two terminal contacts. The switch further comprises a moving mechanism (6), which comprises a motorized device (9) and a support sliding element (21) for the movable contact. The support sliding element is driven by the moving mechanism and the motorized device so that the movable contact can move between the operating condition and the open position.

Description

Technical Field

[0001] The present invention relates to switches and transfer switches with innovative structures and functional configurations to achieve a more compact structure.

[0002] More specifically but not exclusively, the present invention relates to transfer switches suitable for industrial applications involving high currents, particularly in the railway field. Background Art

[0003] As is well known in this particular technical field, a switch is an electrical component that can "make" or "break" a circuit to interrupt the current or transfer it from one conductor to another. The mechanism of the switch removes or restores the conductive path in the circuit during operation.

[0004] A particular type of switch is the disconnect switch. The disconnect switch is used to ensure that the circuit is completely de-energized for repair or maintenance. Such switches are often used in distribution and industrial applications where the drive power of machinery must be removed for adjustment or repair. High-voltage disconnect switches are used in substations to allow isolation of equipment such as circuit breakers, transformers, and transmission lines for maintenance. Disconnect switches are generally not used for normal control of the circuit but only for safety isolation. Disconnect switches can be operated manually or automatically.

[0005] Unlike load switches and circuit breakers, disconnect switches lack an arc suppression mechanism, which appears when the conductor carrying a high current is electrically interrupted. Therefore, they are unloading devices designed to open only after the current has been interrupted by some other control device.

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

[0007] This is the case of the so-called "transfer contact" or "transfer switch", where a set of three electrical contacts is precisely arranged, and the contact with one device is interrupted and then contact with another device is established. The control of the contacts can be manual or part of a disconnect switch under electronic control. A disconnect switch can consist of more than one set of transfer contacts.

[0008] A set of three contacts is called a pole. A transfer disconnect switch can have one or more poles. The contacts in the pole can be made of materials such as tungsten, silver alloy, or gold plating, which are hard and resistant to burning and corrosion, or can be simple copper if no arc is foreseeable.

[0009] Transfer switches can have different configurations: a single-pole double-throw or single-pole switch is a toggle switch that switches only from one device to another, while a double-throw or single-pole double-throw center-off switch has two "on" positions and one "off" position.

[0010] However, switches of this type are usually too large, especially in those applications where space needs to be optimized to organize as many circuits as possible.

[0011] In view of this, for example, patent application JP2,878,417B2 describes a changeover switch that uses an arrangement of two parallel-connected lead switches that require less space.

[0012] Although this arrangement offers undoubted advantages, there are still disadvantages, especially the need for a more complex internal structure and other dimensional increases due to this particular arrangement. Summary of the Invention

[0013] The technical problem of the present invention is to provide a switch with a more compact structure.

[0014] Another object of the present invention is to provide a switch that can ensure more efficient operation in terms of rated current to support a high level of short-circuit current.

[0015] Another object of the present invention is to provide a switch that can ensure higher reliability and a long service life.

[0016] Another object of the present invention is to provide a switching device that does not require complex manufacturing costs.

[0017] Finally, the object of the present invention is to provide a switch that can ensure easy installation on a complex electrical system.

[0018] Based on the idea of the solution of the present invention, the idea is to provide a more compact mechanism that can provide effective disconnection in the interconnection between at least two contact terminals and establish a connection with another contact terminal when needed.

[0019] According to the above solution idea, the technical problem is solved by a switch that includes a switch body adapted to accommodate switch components, at least two terminal contacts extending from the switch body, and at least one movable contact that can move between an operating position and a disconnected position. In the operating position, the movable contact is electrically connected between the at least two terminal contacts, and in the disconnected position, the movable contact is electrically disconnected from the at least two terminal contacts. The switch further includes a moving mechanism that includes a motor driving device and a support sliding element for the movable contact. The support sliding element is driven by the moving mechanism and the motor driving device so that the movable contact can move between the operating position and the disconnected position; the movable contact is a plate rod that extends laterally with respect to the support sliding element.

[0020] Preferably, the switch body is suitable for accommodating all switch components.

[0021] Preferably, the movable contact is adapted to establish a physical and electrical connection between the at least two terminal contacts and to disconnect the physical and electrical connection between the at least two terminal contacts.

[0022] This structure ensures obtaining a switch that allows for reliable and effective electrical connection and disconnection.

[0023] Furthermore, the switch includes at least one releasable clamping device for each position of the movable contact for clamping at least one end of the movable contact.

[0024] Advantageously, the releasable clamping device ensures the correct positioning and support of the movable contact for electrical connection.

[0025] According to a particular aspect of the invention, the switch includes at least two releasable clamping devices that are fixed in the switch body corresponding to each position reached by the movable contact, and wherein the at least two releasable clamping devices are positioned at these positions at two opposite ends of the movable contact.

[0026] Advantageously, due to this special construction, the switch achieves good structural balance, avoiding possible deformation of the movable contact and incorrect connection between switch components.

[0027] According to another aspect of the invention, the switch further includes at least one guiding system that extends centrally along the central axis of the switch body to guide the movable contact between an operating position and a disconnection position; the plate lever extends transversely with respect to the guide.

[0028] This particular aspect allows for rapid and correct movement between the operating position and the disconnection position.

[0029] Preferably, the moving mechanism is a rotary motion mechanism.

[0030] According to a particular aspect of the invention, the rotary motion mechanism includes at least a pair of gears that are moved by a motorized device, and the pair of gears in turn move at least a rod that is connected to a support sliding element of the movable contact to move the movable contact between an active position and a disconnection position.

[0031] Advantageously, this structural configuration allows for a very compact overall structure of the switch while ensuring effective operation.

[0032] According to a particular aspect of the changeover switch, an additional third fixed terminal contact is provided such that when the connection between two contacts is disconnected, a connection is established between the other two contacts.

[0033] Preferably, according to the latter aspect, the actuating means moves the at least one movable contact between a first position, which establishes a physical and electrical connection between two terminal contacts, and a second position, which establishes a physical and electrical connection between two other terminal contacts including the third fixed contact, while breaking the physical and electrical connection at the first position.

[0034] This solution is compact and allows for rapid establishment of different electrical connections within the switch.

[0035] According to another aspect, at least one of the terminal contacts is connected to a contact strip extending along the periphery of the switch body.

[0036] Preferably, the movable contact can be connected to the contact strip in different operating positions by means of at least one connecting part.

[0037] According to another preferred aspect, the switch body can be connected to a similar switch body in a modular manner. This aspect allows for the creation of a single, space-safe structure suitable for more complex operations of electrical connection and disconnection.

[0038] Finally, it should be noted that the switch is suitable for implementation in a corresponding electrical system, particularly but not exclusively in high-voltage applications.

[0039] Further features and advantages of the switch according to the invention will become more apparent from the following description, given by way of non-limiting example with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] - Figure 1 shows a perspective view of a switch implemented according to the invention;

[0041] - Figure 2 shows Figure 1 the rear perspective view of the switch;

[0042] - Figure 3 shows a front schematic view of the switch Figure 1 in an operating configuration;

[0043] - Figure 4 shows a front schematic view of the switch Figure 1 in another operating configuration;

[0044] - Figure 5 shows a front schematic view of the switch Figure 1 in yet another operating configuration. DETAILED DESCRIPTION

[0045] Referring to the accompanying drawings, reference numeral 1 schematically and globally shows a change-over switch implemented according to the invention.

[0046] This switch is specifically designed for industrial applications where high DC current circuits must be connected or disconnected in a safe and reliable manner.

[0047] Transfer switch 1 provides a switch body 2 that includes all the moving parts of switch 1, which will be disclosed hereinafter.

[0048] In Figure 1 the specific embodiment shown, a transfer switch will be specifically disclosed, but the same mechanism can be applied to disconnect switches.

[0049] In Figure 1 the described exemplary embodiment, the switch body has a generally parallelepiped shape, with a depth much smaller than the other two dimensions.

[0050] Furthermore, specifically, Figure 1 switch 1 according to the present invention is shown, with its front surface removed to show the elements housed in switch body 2, but the motor is not shown to show the elements below.

[0051] Switch body 2 includes a base 3 that is adapted to be connected within a more complex system through two notches 4, or simply used as a support for switch 1.

[0052] Switch 1 can be internally divided into two main parts, a lower part 5 near base 3 and an upper part 7 standing on top of said lower part 5. A moving mechanism 6 is housed in the lower part, and an electrical connection group 8 is housed in the upper part. These spatial references relate to the installation of the switch extending in a vertical position.

[0053] Moving mechanism 6 includes a motorized device 9. In a preferred embodiment, motorized device 9 is an electric motor. Moving mechanism 6 is preferably a rotational motion mechanism.

[0054] The motorized device is covered by a horizontal partition 11 to protect motorized device 9 and divide lower part 5 and upper part 7.

[0055] The motorized device is operatively connected to a gear system 12 that includes a main gear 13 and a secondary gear 14. The tooth engagement occurs in the depth direction of the switch body.

[0056] Shaft 15 is connected to a planar surface 16 of main gear 13. In Figure 1 the exemplary embodiment shown, the shaft has a three-lug shape for better force distribution.

[0057] Rod 17 is connected to a lug 19 of shaft 15 at one of its ends 18. Thus, the rotation of main gear 13 causes the rotation of shaft 15 and, consequently, the translational movement of rod 17.

[0058] In other words, the shaft 15 and the rod 17 represent the piston rod / crankshaft mechanism.

[0059] The rod 17 also represents the connection between the lower part 5 and the upper part 7.

[0060] The rod 17 has a U-shaped cross-section in the depth direction of the switch body 2 at the opposite end 20.

[0061] The cavity of the U-shaped opposite end 20 is complementary to the support sliding element 21.

[0062] The support sliding element 21 includes a front plate 22 and a rear plate 23 arranged in parallel. Approximately at the average size of the front plate 22 and the rear plate 23, the front plate and the rear plate are laterally connected by a connecting part 24 in the depth direction of the switch body. In other words, the support sliding element is H-shaped in the depth direction of the switch body 2.

[0063] The front plate 22 has a rectangular cross-section with a recess 25 on the lower side facing the rod 17. The recess 25 is inserted into the cavity of the U-shaped opposite end 20 of the rod 17 and is preferably fixed by a lateral pin.

[0064] The rear plate 23 is on the rear surface 26 of the switch body 2.

[0065] 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 shape with a groove 28 to slide on the guide 27.

[0066] There is no limitation on other types of guides 27 on which the support sliding element 21 can slide.

[0067] The moving contact 29 is placed on the upper side 30 of the connecting part 24 and is fixed, for example, by screws or bolts. The moving contact 29 is a strip or a plate bar extending laterally with respect to the guide 27.

[0068] Therefore, the sliding of the support sliding element 21 causes a translational movement of the moving contact 29.

[0069] At the lower position of the support sliding contact 21 and the moving contact 29, a pair of clamping devices 31 for electrical connection and clamping action are provided at the opposite ends of the strip-shaped moving contact 29. These clamping devices 31 are oriented upward.

[0070] In contrast, at the upper position of the support sliding contact 21 and the moving contact 29, a pair of opposite clamping devices 32 are provided at the opposite ends of the moving contact 29. The clamping parts of the opposite clamping devices 32 face the clamping parts of the clamping devices 31 and are therefore oriented downward.

[0071] Thus, the moving contact 29 is moved between two end positions by supporting the sliding contact 21, in which the moving contact is locked in place by the clamping device 31 and the opposing clamping device 32, respectively.

[0072] In the specific embodiment shown in the drawings, the clamping device 32 is a specific small pliers, but without departing from the scope of protection defined by the claims, the use of other different releasable locking devices is not restricted.

[0073] For each position of the moving contact 29, the use of only one clamping device 32 is not restricted either.

[0074] For each position of the moving contact 29, a configuration with two clamping devices 32 is preferably used because this configuration ensures better structural balance.

[0075] An opening 33 is provided on the lateral side 49 of the switch body 2.

[0076] The terminal contact 34 projects through this opening 33.

[0077] The terminal contact 34 is associated with a contact strip 35 that extends peripherally from the opening 33 on the lateral side 49 to the upper end 36 of the opposite side 37 of the switch body 2.

[0078] At the two end positions of the moving contact 29, two additional openings 38 and 39 parallel to the opening 33 are provided.

[0079] Two corresponding terminal contacts 40 and 41 project from the openings 38 and 39. In the disconnect switch, only the terminal contact 40 that projects from the opening 38 is provided.

[0080] Two corresponding connecting elements 42 and 43 are provided at the opposite side 37 of the openings 38 and 39 and are in contact with the contact strip 35. When the moving contact is in its end position, the connecting elements 42, 43 allow the contact strip 35 to be connected to the moving contact 29 and to be connected to the corresponding terminal contacts 40 or 41, respectively.

[0081] In other words, depending on the position of the moving contact 29 along the contact strip 35, two alternative connection configurations are provided between the terminal contact 34 and the terminal contacts 40, 41 accordingly.

[0082] In the case where the terminal contact 34 is on the opposite side with respect to the corresponding terminal contact 41, the contact strip 35 is not required for the switch 1 to operate properly.

[0083] In addition, in the case of a simple disconnect switch, only one connecting element 42 is provided.

[0084] Other configurations are possible without departing from the scope of protection defined by the claimed claims. Depending on the required connection configuration, different positioning of the terminal contacts 34, 40, 41 can be provided on opposite or different sides of, for example, the switch body 2 through corresponding openings (33, 38, 39 and the opening near the terminal 42 (not shown in the figure)).

[0085] As Figure 2 shown, another important feature of the switch 1 according to the present invention is the presence of an electronic board 44 associated with the rear side of the switch body 2 outside the switch body 2.

[0086] The electronic board 44 is arranged to regulate the power supply to the actuating device 9. More specifically, in this exemplary but non - limiting embodiment, the electronic board 44 is configured to provide the correct voltage and current values to the coil at a predetermined planned time.

[0087] The provision of these correct voltage and current values is independent of possible deviations of the control power supply and is provided within an operating temperature variable range between - 40 °C and + 75 °C.

[0088] By means of heat - dissipating elements and circuit recovery devices mounted on the electronic board 44, high - reliability operating conditions of the electronic board 44 can be ensured.

[0089] Furthermore, according to more stringent railway requirements, the control board 44 is provided with suitable resistance to radiation and conducted interference.

[0090] A further specific insulation of at least 1500 V (at 50 Hz, within 60 s) with respect to the ground is provided.

[0091] The electronic board 44 is mounted at a predetermined small distance from the switch body 2. In this regard, struts 45 are provided on the rear surface of the switch body 2.

[0092] These struts 45 are integrally formed in the structure of the switch body 2 as cylinders with open ends to accommodate the insertion of fixing screws 46.

[0093] The protective cover 47 on the electronic board 44 is provided with holes 48 for the fixing screws 46 to pass through. The protective cover 47 is preferably square with rounded - off edges.

[0094] External electronic connections 48 are provided from the electronic board to pass through specific holes in the protective cover 47.

[0095] The operation of the switch according to the present invention will be described below, particularly with regard to an exemplary Figures 3 to 5 which shows three stages during the movement of the moving mechanism 6.

[0096] Actuation of the mobile device 9 causes rotation of the gear system 12. Rotation of the main gear 13 causes rotation of the shaft 15 connected to the planar surface of the main gear 13. Rotation of the shaft 15 causes translational movement of the rod 17, one end of which is connected to one end of the shaft 15. The translational movement of the rod 17 is on the support sliding element 21 and thus causes a push-pull action of the moving contact 29. At the end positions of the support sliding element 21 and the moving contact 29, at least one, preferably two, clamping devices 32 are provided to hold the moving contact 21 in place. At each end position of the moving contact 29, a terminal contact 40, 41 projects outside the switch body 2. The moving contact 29 forms an electrical circuit with such components: the terminal contact 40 or 41; the connecting element 42 or 43 on the opposite side of the switch body 2; the contact strip 35 that contacts the connecting element and extends peripherally to the terminal contact 34, which is on the same side as the terminal contacts 40, 41 in this embodiment.

[0097] Thus, by the movement of the moving contact 29 operatively connected to the moving mechanism 6, switching can be made between two possible electrical paths.

[0098] In a conventional disconnect switch, only two terminal contacts 34, 40 are provided, so the rotation of the gear system 12 and the shaft 15 and the corresponding translational movement of the rod 17 and the support sliding element 21 only cause the moving contact 29 to move between the operating position and the open position where there is an electrical connection between the terminal contacts 34, 40.

[0099] Advantageously, the switch 1 has a compact structure, which is ensured by the special construction of the moving mechanism 6 employing the gear system 12 and the mechanism of the piston rod / crankshaft type.

[0100] Furthermore, advantageously, this solution can be applied both to a disconnect switch, where the moving mechanism 6 disconnects the physical and electrical connection between two terminal contacts, and to a changeover switch, where the physical and electrical disconnection between two terminal contacts corresponds to the formation of a physical and electrical connection between two other terminal contacts.

[0101] Still advantageously, the structure of the switch 1 allows it to be connected in series with a common base in order to obtain a larger and more complex switch with a space-safe structure.

[0102] Another advantage is that since the moving mechanism 6 itself has a simple construction and provides simple operation, it is hardly affected by important faults and is easy to repair. Therefore, the switch provides higher reliability as well as fast and inexpensive maintenance.

[0103] Another advantage is that due to the different possible configurations of the terminal contacts, they can project from different sides of the switch body with minimal changes, thus allowing the switch 1 to be installed in different circuits in different arrangements.

[0104] Therefore, the present invention is applicable to most applications that require high-current switching.

[0105] Another advantage of the present invention is that it can be simply used by an operator in any department, without any specific knowledge, but only based on visible connection requirements.

[0106] Another advantage of the present invention is that it does not require specific manufacturing, which is important for components that are apparently intended for mass production.

[0107] Advantageously, the disconnect switch according to the present invention can also be used in high alternating current applications.

[0108] Finally, the switch 1 can be implemented in a more complex electrical system.

[0109] In the foregoing description, directional terms such as: "forward", "backward", "front", "rear", "upper", "lower", "above", "below", "upward", "downward", "top", "bottom", "side", "vertical", "horizontal", "perpendicular" and "lateral", and any other similar directional terms, only relate to the device shown in the drawings and do not relate to the possible use of the device. Therefore, when these directional terms are used to describe a contactor in an upright vertical position on a horizontal surface, their meaning is only to identify a part of the device relative to another part of the device, as shown in the figure.

[0110] As used herein, the term "comprising" and its derivatives are open-ended terms that specify the presence of the stated features, elements, components, groups, integers and / or steps, but do not preclude the presence of other unstated features, elements, components, groups, integers and / or steps. This concept also applies to words with similar meanings, for example, the terms "having", "including" and their derivatives.

[0111] In addition, when used in the singular form, the terms "member", "section", "part", "portion" and "element" can have a dual meaning of a single part or multiple parts.

Claims

1. A switch (1), comprising: A switch body (2), the switch body being adapted to accommodate switch components; At least two terminal contacts (34, 40), the at least two terminal contacts extending from the switch body (2); At least one movable contact (29), the at least one movable contact being movable between an operating position and an open position, in the operating position, the movable contact (29) being electrically connected between the at least two terminal contacts (34, 40), and in the open position, the movable contact (29) being electrically disconnected from the at least two terminal contacts (34, 40); A moving mechanism (6), the moving mechanism including a motor driving device (9); A support sliding element (21) for the movable contact (29), driven by the moving mechanism (6) to move the movable contact (29) between the operating position and the open position; The movable contact (29) is a plate rod extending transversely with respect to the support sliding element (21); Characterized in that the switch further includes An additional third fixed terminal contact (41); and Wherein at least one terminal contact (34) is connected to a contact strip (35), the contact strip (35) extending along the periphery of the switch body (2); and Wherein depending on the position of the movable contact (29) along the contact strip (35), two alternative connection configurations are provided between two terminal contacts (34, 40) and two additional terminal contacts (34, 41) respectively.

2. The switch (1) according to claim 1, further comprising at least one releasable clamping device (32) for each position of the movable contact (29), for clamping at least one end of the movable contact (29).

3. The switch (1) according to claim 2, including at least two releasable clamping devices (32), the at least two releasable clamping devices being fixed in the switch body corresponding to each position to be reached by the movable contact (29), and wherein the at least two releasable clamping devices (32) are positioned at these positions at two opposite ends of the movable contact (29).

4. The switch (1) according to any one of the preceding claims, further comprising at least one guide (27) extending centrally along the central axis of the switch body (2) to guide the movable contact (29) between the operating position and the open position; the plate rod extending transversely with respect to the guide (27).

5. The switch (1) according to any one of claims 1 to 3, wherein the movable contact (29) is adapted to establish a physical and electrical connection between the at least two terminal contacts (34, 40), and is adapted to disconnect the physical and electrical connection between the at least two terminal contacts (34, 40).

6. The switch (1) according to any one of claims 1 to 3, wherein the moving mechanism (6) is a rotational motion mechanism.

7. The switch (1) according to claim 6, wherein the rotary motion mechanism comprises a gear system (12) moved by the actuating means (9), the gear system (12) in turn moving at least a shaft (15) and a rod (17), the rod (17) being connected to the support sliding element (21) for the moving contact (29) so as to move the moving contact (29) between the operating position and the open position.

8. The switch (1) according to claim 1, wherein the actuating means (9) moves the at least one moving contact (29) between a first position and a second position; the first position forming a physical and electrical connection between two terminal contacts (34, 40); the second position establishing a physical and electrical connection between another two terminal contacts (34, 41) including the third fixed terminal contact while breaking the physical and electrical connection of the first position.

9. The switch (1) according to claim 1, wherein the moving contact (29) is capable of being connected to the contact bar (35) in different operating positions by at least one connecting element (42).

10. The switch (1) according to any one of claims 1 to 3, wherein the switch body (2) can be connected to a similar switch body (2) in a modular manner.

11. An electrical system comprising at least one switch (1) according to any one of claims 1 to 10.

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