WO2015059325A1

WO2015059325A1 - Helical switch

Info

Publication number: WO2015059325A1
Application number: PCT/ES2014/070759
Authority: WO
Inventors: José Óscar Andaluz Sorlí
Original assignee: Gorlan Team, S.L.U.
Priority date: 2013-10-22
Filing date: 2014-10-06
Publication date: 2015-04-30
Also published as: EP2866244B1; EP3196911B1; EP3196911A1; ES2633768T3; ES2712068T3; EP2866244A1

Abstract

The invention concerns a current cut-off switch enabling the electric arcs produced in an electric circuit during circuit cut-off and closing operations to be extinguished rapidly, effectively and completely, making it particularly suitable for use in the event of direct current failure. The switch comprises at least one pair of fixed contacts (4, 4') and a movable contact (9) mounted in a rotor (2) made of insulating material. The rotor (2) is adapted to move so as to define a helical movement relative to the fixed contacts. The switch enables the current to be cut off solidly since the insulating material of the rotor (2) is interposed immediately between the two fixed contacts (4, 4') at the very moment when the power is cut off.

Description

HELICOIDAL SWITCH D E S C R I P C I Ó N

OBJECT OF THE INVENTION

The present invention belongs to the field of electrical switches and / or disconnectors, specially adapted for extinguishing the electric arc produced in the opening and closing of the contacts thereof.

More specifically, an object of the present invention is to provide a power cut-off switch, which allows an effective rapid extinction of the electric arcs produced in an electric circuit during the cutting and closing operations thereof, all in a volume reduced.

The switch of the invention is especially applicable to the cutting of high power direct current, where the extinction of the electric arc is more difficult than in alternating current.

BACKGROUND OF THE INVENTION

It is now known that electric arcs or voltaic arcs produced in electric circuits can cause multiple problems, because the caloric energy produced during an electric arc is highly destructive. Some of these problems are: deterioration of the switch material, breakdowns and / or total or partial destruction of electrical installations, including damage to people from burns or other injuries.

The problem of the extinction of the electric arc is especially pronounced in the cut of direct current where, unlike the alternating current, there is no zero crossing, so that an arc is produced that must be eliminated as soon as possible by means of the ionization of the medium and increased dielectric strength. Several techniques are currently known to extinguish the electric arc produced at the opening and closing of the contacts of a current switch or disconnector. All these techniques have as a common objective to ensure that the heat dissipated energy of the electric arc is as small as possible, with the aim of being zero. For this, the critical variable on which it acts is the control of time, trying to make the shutdown speed of the electric arc as fast as possible.

To achieve this goal, several techniques are known, among which are: a) increase in the separation distance between the fixed and mobile contacts of the electric switch, which implies a greater volume of air between them, and therefore, a larger size of the switch.

- Increased speed of the firing devices.

- Radial cut.

- Serial simultaneous contacts. b) increase in the length or "elongation" of the electric arc for the same instant of time.

- Cameras extinguish sparks.

- Magnetic and pneumatic blowing. c) cooling of the electric arc from auxiliary means to reduce the harmful calorific effects, such as the use of sulfur hexafloride SF ₆ under pressure. d) action on the dielectric strength of the medium to avoid re-ignition of the arc due to the influence of the electric field due to potential differences.

However, although there are currently electrical cut-off switches that combine some of the techniques mentioned above: camera turns off chips with magnetic or pneumatic blow, separation of radial contacts instead of linear, etc., these current switches still do not satisfactorily solve their main task of extinction of the electric arc, since the extinction time is still too much high and there is still deterioration of the material, especially in very demanding applications such as high-power DC cutting.

In addition, known techniques for arc extinction generally involve an increase in the volume of the switches due to the volume of air needed between the contacts.

The operation of the mechanisms of cut of the switches, usually implies some type of impact between pieces, that in the long run causes the deterioration by wear of the material that can take to the destruction of the switch.

DESCRIPTION OF THE INVENTION By means of the present invention, the aforementioned drawbacks are solved, providing a power cut-off switch that integrates several arc extinction techniques simultaneously and synergistically, achieving a fast and effective cutting of the electric arc, in a small space. and in the same instant of time.

Thus, a first aspect of the invention relates to an electric current cut-off switch, comprising at least one pair of fixed contacts and a movable mobile contact between a closing position of the switch in which it establishes electrical continuity with the fixed contacts, and an opening position in which the current flow cuts.

The mobile contact is arranged between the fixed contacts, and is movable following a helical displacement relative to an axis. The helical displacement of the mobile contact with respect to the fixed contacts is a combination of a radial movement together with longitudinal movement of the mobile contact, which has the effect of achieving a greater length of separation between contacts (elongation of the electric arc) to extinguish the arch quickly and in a small space.

In this way, the invention achieves a helical elongation of the length of the electric arc without requiring a larger volume of air, which implies that for the same nominal cut-off current, the switch may have a smaller size compared to a state of the art switch. Preferably, the switch incorporates a rotor of insulating material, in which said at least one mobile contact is mounted, where the rotor is movable with a helical path relative to a rotation axis, and thereby causes the helical displacement of the mobile contact . Thanks to the helical movement, the tangential speed of the cut-off point can be increased simply by increasing the turning radius, thus increasing the cutting speed in a simple way, without the need for complex mechanisms and with a reduced number of parts, so manufacturing of the switch is very simple.

The rotor can be a cylindrical body or with a generally cylindrical shape, which is to move helically with respect to its axis of revolution in a reciprocal manner, that is to say in both directions, to move from the closed position to the cutting position and vice versa.

A pair of fixed contacts have a contact surface arranged to be contacted by a movable contact, and the rotor is configured such that in the opening position of the switch, the rotor insulating material is in direct contact with the fixed contacts and It covers a major part of the contact surface of the fixed contacts, so there is no air chamber around the moving contacts and the appearance of the electric arc is reduced or disabled.

This particularity has the effect that by means of the switch of the present invention, a solid cut of the current is achieved, which means that due to the helical path of the rotor, in the electrical cut-off position of the switch (circulation is prevented of current), the rotor insulating material is instantly interposed between the two moving contacts at the same moment in which the electrical cut occurs, achieving the electrical isolation of the cut-off points with the interposition of an insulating means or material solid between contacts fixed and mobile, instead of the insulating medium being air, oil or other insulating liquid as is known in the state of the art.

DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical implementation thereof, a set of drawings is attached as an integral part of said description. where for illustrative and non-limiting purposes, the following has been represented:

Figure 1 shows an exploded view of an exemplary embodiment of a helical displacement cut-off switch according to the invention.

Figure 2 shows the embodiment of Figure 1 in the initial position of 0 ^or rotation of the rotor, which corresponds to the electrical closing position of the switch (the passage of current is allowed), where drawing 2a is a view in front elevation without the stator, drawing 2b is a profile view, drawing 2c is a perspective view, and drawing 2d is another perspective view with the stator coupled and partially sectioned.

Figure 3.- shows a representation similar to that of figure 2, when the rotation of the rotor is approximately 45 ° with direction of rotation according to the hands of a clock, which corresponds to an electric cut-off position.

Figure 4.- shows a representation similar to that of figure 2, when the rotor has rotated an angle of 90 ° with respect to a vertical axis, and the separation between the movable contact and the fixed ones is maximum.

Figure 5 shows a schematic representation of an alternative embodiment to produce the helical rotation of the rotor, which is made by a body external to the housing, in which the rotor is threaded. The view consists of a sectional side elevation. Figure 6.- is an exploded view similar to that of Figure 1 of another preferred embodiment of the invention, in which in addition to the switch function, a serial-parallel-series connection of the contacts is implemented.

Figure 7 shows a perspective view of another embodiment of Figure 6, where the drawing (a) is a view of a rotor provided with ventilation fins, the drawing (b) is a view of said rotor in the electric cutting position; and the drawing (c) is a view of said rotor in the closing or electrical continuity position of the switch.

Figure 8 shows a sequence of movement of the mobile contacts of the embodiment of Figures 6 and 7, to make the change of serial to parallel connection of the mobile contacts and fixed contacts. The dyh drawings are perspective views, and the rest of the drawings are side elevation views. The rotor and the stator have not been shown in the figure to improve the vision of the movement of the moving contacts. The sequence of movement is as follows: drawing a: Off switch, 0 ^or mobile contacts position.

drawing b: Off switch, 20 ° moving contacts position.

drawings c and d: On switch, 30 ° moving contacts position.

Drawing e: On switch, 45 ° moving contacts position.

drawing f: On switch, 60 ° mobile contacts position, the transition occurs in the connection, the contacts go from being connected in series to being connected in parallel.

drawings g and h: On switch, 90 ° moving contacts position.

The sequence of drawings shows the movement of the contacts to move from the cut-off position (Off) of the switch to the electric close position (On), where the moving contacts move from left to right in the figure. The reverse transition, that is to say On to Off step is identical but following the reverse order of drawings, that is, from (g) to (a), moving in this case the moving contacts from right to left in the figure. The arrows indicate the path of the electric current in the On position. PREFERRED EMBODIMENT OF THE INVENTION

An exemplary embodiment of a solid cut helical switch (1) comprising a stator (11) including a housing is shown in Figure 1

(7.7 ^' ) of insulating material, intended to be mounted in a fixed position of an electrical installation for example in an electrical panel, and which may be formed by two halves (7.7 ^' ) coupled together. The stator (11) inside forms a chamber with a cylindrical general shape (3) within which a rotor (2) made of an insulating material is housed, and so that the rotor (2) is adapted to move defining a helical movement within said chamber and with respect to its axis of revolution (X).

A pair of fixed contacts (4.4 ^' ) are mounted in said housing (7.7 ^' ), which form contact terminals (6.6 ^' ) that emerge in said chamber (3) and are curved in correspondence with the curvature of the outer surface of the rotor (2). In turn, the rotor (2) incorporates at least one mobile contact (9) which is rotatably integral with the rotor and therefore also defines a helical movement on the "X" axis.

Preferably the rotor (2) at least partially hollow and has two transverse openings (8) located at diametrically opposite points thereof. To improve the conduction, the mobile contact (9) consists in this embodiment of one or more metal plates (5.5 ^' ) superimposed and in direct contact, and so that the two ends of the metal plates (5.5 ^' ) they emerge diametrically through said openings (8) of the rotor, being flush with its outer surface, for which said ends are curved according to the curvature of the outer surface of the rotor.

The outer surface of the rotor (2) slides in permanent contact with the contact terminals (6.6 ^' ) of the fixed contacts. The fixed contacts (4.4 ^' ) and the mobile contact (9) are arranged to come into contact in the closing position of the switch (1) (figure 2), while in the electrical cut-off position of the switch (figures 3 and 4), the fixed contacts (4.4 ^' ) are in contact with the rotor insulating material (2). For this, a part of the rotor has a matching dimension with the separation distance of the fixed contacts (4.4 ^' ), which can be arranged diametrically opposite to the axis of revolution (X) of the rotor (2).

Preferably, the switch further comprises at least one ring (10) of insulating material, mounted with rotation capacity within the cylindrical chamber (3) of the stator (11), for which the housing (7) has seats (12 ) in the chamber (3), in which said rings are housed, and so that the inner surface of the rings is flush with the surface of the chamber (3). The diameter of the cylindrical chamber (3) is coincident or slightly larger than the external diameter of the rotor (2), to allow it to slide therein tightly. The rotor (2) slides on said rings (10), which in turn are rotatable with respect to the housing (7.7 ^' ) such that the rings (10) act as bearings that facilitate the rotation of the rotor (2 ). For this purpose, the rings (10) can be manufactured with an insulating material that has a low friction.

The insulating rings (10) that surround the rotor (2) perimetrically also serve to guide the rotor (2) in its helical movement, and the electrical isolation of the moving contacts (9).

The stator (11) and the rotor (2) have ventilation windows, specifically the windows (13) of the rotor and the windows (14) of the stator, which are positioned so that they are superimposed on the electric closing position of the switch (as shown in Figure 2d), thus forming a ventilation channel that communicates the inside of the rotor (2) with the outside of the stator (11) allowing ventilation of the switch and the output of the gases generated during operations of cut of the current.

To cause the helical displacement of the rotor (2) with respect to its axis of revolution (X) inside the chamber (3), the stator and the rotor are configured forming a threaded and complementary coupling between them. Specifically, in the case of figure 1, the rotor has on its outer surface one or more channels (15) of helical trajectory, cooperating with ribs (16) existing inside the chamber (3) with analogous shape, of so those nerves are inserted into said channels and slide over them. The person skilled in the art will understand that other configurations are possible, so that the stator and the rotor are threaded together in a manner analogous to a nut and a screw, where the rotor would be the rotating screw with respect to the stator.

Alternatively, the helical rotation of the rotor (2) is carried out by means of rotor actuation means external to the housing, specifically by an external body (29) to the housing as shown in Figure 5, so that an extension (2 ^' ) of the rotor (2) is housed inside that body (29) and rotates on it by means of a threaded coupling (30) forming complementary to both elements. In this embodiment of Figure 5, the friction between the rotor (2) and the housing (7) is minimal, since the rotor relies mainly on the body (29), so that there would only be contact between the moving contacts and the housing or fixed contacts (not shown in that figure). The extension (2 ^' ) of the rotor (2) consists of an axially coupled body at one end of the rotor (2) outside the chamber (3) of the housing (7.7 ^' ). The external body (29) is fixed, for example it can be fixed to the housing itself (7) or to another fixed element of the switch.

The rotor (2) is driven by conventional external means, for example a connecting rod (17) coupled with an emerging pin (18) of the rotor, which is in turn actuated by any appropriate mechanism. Said drive means cause the helical movement of the rotor, in one direction or another, that is to say, reciprocally along the axis (X) between a closed position and an electrical cut-off position of the switch.

To enhance the effect of extinguishing the arc, the switch of the invention can incorporate the cutting of the electric arc by means of the series of contacts, together with the increase of the arc length at each cut point. For this, as shown in Figure 1, the switch includes two or more movable contacts (9) mounted on the rotor in the same position but at a different axial position. One or more plates

(19,19 ^' ) of conductive material are mounted on the stator (11) outside the rotor, which respectively incorporate shoes (20,20 ^' ) and are arranged so that in the electrical closing position of the switch, they connect in series the mobile contacts (9) between the fixed contacts (4.4 ^' ) as shown further clearly in figure 2b, in which the arrows indicate the direction of circulation of the electric current. In this way, the arc is divided into several cutting points, so its extinction is easier.

The plates (19,19 ^' ) are permanently pressed against the fixed contacts (9) by an elastic means, in this case by means of plates (21, 21 ^' ) formed and placed between the plates (19,19 ^' ) and the fixed terminals (4.4 ^' ).

A pair of metallic connection terminals (22,22 ^' ) in the form of a plate, are used for the electrical connection of the switch with an external circuit. Said terminals (22,22 ^' ) have a plate shape and are arranged in opposite parts of the housing (7.7 ^' ) and are electrically connected to the fixed contacts (4.4 ^' ) with which they are in contact.

On the other hand, the rotor (2) is open at its ends, that is, it is a tubular body, and the switch has a rear shut-off valve (24) mounted in a fixed position at the rear of the housing (7 , 7,), for example by means of a support (26) attached to the housing. The rear valve (24) is configured to be inserted and slid inside the rotor in an adjusted manner at its rear, when the rotor moves towards said valve in its extreme position in the movement to produce the electrical cut. In the electrical shut-off position of the switch, the rear shut-off valve (24) does not seal the rotor, as seen in Figure 2b, thus allowing air circulation into it.

Similarly, on the front of the rotor (2) the switch has a front shut-off valve (25) mounted in a fixed position on the front of the housing (7.7,), for example by means of a support ( 27) attached to the housing. The front valve (25) is housed at all times inside the rotor, specifically in its front part, and is configured to slide inside the rotor tightly sealing it. Alternatively, instead of having a valve, in the embodiment of Figures 1 to 4, the rotor (2) may have a closed end and an open end, such as the rotor of Figure 6.

The front and rear valves (25,24) are cylindrical in shape, and are made with an insulating material, for example a rigid or flexible plastic material.

On the other hand, the rotor (2) has at least one through hole (28) preferably located on the edge of one of the openings (8), so that said hole communicates the inside with the outside of the rotor, and is intended to allow aspiration of the electric arc into the rotor, as will be described later.

The operation of the switch to produce the closing and cutting of electric current is illustrated in Figures 2 to 4.

In the situation of figure 2 the switch is in the electric closing position, and as shown in the figure, the three mobile contacts (9) are connected in series by means of the plates (19,19 ^' ) and their shoes (20 , 20 ^' ), and in turn a mobile contact (9) is connected to a first fixed contact (4), and another mobile contact (9 ^" ) is connected to a second fixed contact (4 ^' ), establishing electrical continuity and allowing therefore the current circulation, as indicated by the arrows in figure 2b.

In this same situation, the ventilation windows (13,14) of the rotor and stator respectively, are coincident, that is to say they are superimposed as seen in Figure 2d, whereby the inside of the rotor is communicated with the outside of the stator, allowing its natural ventilation by air circulation, as indicated by the arrows in figure 2d. In addition, thanks to the fact that the windows (13,14) are coincident in this position, the mobile contacts (9, 9 ^' , 9 ^" ) inside the rotor are visible from the outside of the switch, which provides the additional advantage of that the state of the switch can be visually inspected, which can be useful for example for an operator performing maintenance work.

To perform the electric cut, the rotor (2) is rotated according to the hands of the clock seen in Figure 2 a, whereby the rotor moves axially and defining a helical path in the direction of arrow "A" of the Figure 3b, at the same time as the rear shut-off valve (24), upon reaching approximately 40 ° of rotation, seals the rear open end of the rotor before the current flow is cut. The mobile contacts (9.9 ^' , 9 ^" ) are helically moved in the same direction, sliding on the shoes (20,20 ^' ) until they reach a position where they cease to be connected with the shoes and the current flow is cut off, as can be seen in figure 3d. The rotor (2) is configured such that in the opening position of the switch, the rotor is in direct contact with the contact surfaces of the shoes (20,20 ^' ) and covers a major part of the surface of that surface of contact, as clearly seen in the 3d figure. One of the effects or advantages associated with that characteristic, is that at the same moment in which the shoes (20,20 ^' ) and the mobile contacts (9, 9 ^' , 9 ^" ) are no longer connected, the insulating material of the rotor (2) comes into direct contact with the shoes at the same time as it slides on them, so that the electrical cut is made by the immediate interposition of a medium or solid material, instead of air as conventionally happens in the state of the technique.

This interposition of a solid medium occurs at the same time in the two pairs of shoes (20,20 ^' ), that is, the insulation is double, and is carried out under pressure due to the pressure of an elastic medium, in this case the springs (23.23 ^' ) that press on the contact terminals (6.6 ^' ), which are shaped like a plate and have a certain flexural capacity. In this way, the electrical insulation between the two fixed terminals (4.4 ^' ) is significantly enhanced, making arc generation even more difficult.

At the same time that the rotor (2) begins to rotate, the ventilation windows of the rotor (13) begin to hide under the rings (10), conveniently located for such function, and in turn the rotor itself closes the ventilation windows (14) of the stator. The rotor (2) approaches the rear shut-off valve (24) that seals the rear mouth of the rotor. When the rotor has rotated 45 ° it is in the position of figure 3, where the inside of the rotor is completely sealed, since the ventilation windows are closed, and the front and rear ends of the rotor are sealed by the valves (24 , 25).

In such a situation, the air can only circulate through the through holes (28), so that the relative movement between the rotor and the front and rear valves (25,24), they generate a suction similar to that produced by a plunger in a syringe, which produces the aspiration of the electric arc into the rotor, which in turn implies the stretching of the arc and the cooling of the cutting area due to the suction current .

To move from the electric cut-off position to the closed or electric continuity position, the rotor would be rotated counterclockwise as seen in Figure 4 a, whereby the rotor moves in a counterclockwise direction. indicated by the arrow of figure 3b, until the rotor reaches again the position of figure 2.

Alternatively, in the embodiment of Figures 1 to 4, the rotor (2) may have a different shape than a cylindrical one, for example, it may have the shape of the rotor (2) shown in Figure 6 with or without fins (32) . In that figure 6 another preferred embodiment of the invention is shown, in which in addition to the switch function, the movable contacts (9, 9 ^' , 9 ^" ) and the shoes are placed relatively together and are configured in such a way, that as the rotor moves with its helical movement on the axis (X), that is to say by a combination of simultaneous linear and angular movements, the connection of the movable contacts is switched by means of the shoes, between a serial connection thereof to a parallel connection and vice versa in reverse operation.

Thus, in the moments of transition in which the electric arc can appear, that is, transition from conduction to electrical cut (step from On to Off) (figures 8 c, d, e) and vice versa, the shoes connect the contacts Serial mobiles in order to have several cut-off points in series and thus divide the arc and facilitate its shutdown.

At a later time when the possible electric arc has already disappeared, that is, when the normal electric conduction state is reached (figures 8 f, g, h), as the rotor advances, the shoes connect the moving contacts in parallel , in order to divide the current circulation between the existing mobile contacts, and thus reduce the temperature for each of them. The switch of Figure 6 also comprises a stator (11) that includes a housing of insulating material formed by two halves (7.7 ^' ) coupled together, inside which there is a chamber (3) within which it is housed. a rotor (2) made with an insulating material. In this embodiment there are no insulating rings (10) as in the case of figure 1, instead the rotor (2) forms a cylindrical sector (43) with which it supports and slides on a complementary surface (45) formed internally in the stator (11).

The rotor (2) is equally hollow and movable with a helical movement with respect to its axis of revolution (X) inside the chamber (3), the stator and the rotor are configured forming a complementary threaded coupling between them. Specifically, that threaded coupling, in the embodiment of Figures 6 and 7, consists of a pair of metal spheres (39.39 ^' ) placed at diametrically opposite points of the rotor (2), in particular of a cylindrical sector (43) formed in said rotor (2), so that the rotor forms a kind of bearing together with the housing.

In addition, the stator (11) has on the inner surface of the chamber (3) a pair of helical path channels (44.44 ^' ) cooperating with the spheres (39.39 ^' ) so that each sphere slides at along a channel to produce the displacement of the rotor (2) with that trajectory with respect to its axis of revolution (X).

Alternatively, the rotor (2) may be mounted on a body external to the stator (11) and be threaded into that external body as well as the embodiment of Figure 5.

The stator (11) and the rotor (2) have ventilation windows, specifically the windows (40) of the rotor (2) and the windows (14,14 ^' ) of the stator (11), to ventilate the interior of the switch , to which it contributes in this embodiment, the ventilation fins (32) of the rotor (2) removing the air inside the chamber (3), and expelling it outside through the ventilation windows (14,14 ^' ) of the stator (11) in order to improve reducing the temperature of the switch.

The configuration and arrangement of the fixed and mobile contacts of this embodiment is best seen in Figures 7 and 8. The rotor (2) is hollow and has three groups of mobile contacts (9, 9 ^' , 9 ^" ) each group consisting of two or more metal plates (5) superimposed and in electrical contact, which are generally rectangular in shape and are housed inside the rotor, so that they are rotatable in solidarity with the helical displacement of the rotor The ends of the plates (5) emerge slightly through openings (8) of the rotor (2) located at diametrically opposite points thereof The ends of the plates (5) are curved (in the form of arc of circumference) in correspondence with the curvature of the curved surfaces (34,34 ^' ) being flush with them. The position of the three groups of moving contacts (9, 9 ^' , 9 ^" ) in the rotor is the same as seen in figure 7, but at a different axial dimension with respect to the axis (X).

On the other hand, in this embodiment, the switch incorporates as fixed contacts an upper pair of conductive shoes (19,42) mounted in a fixed and upper position of the stator (11) (in the normal position of use of the switch), and a lower pair of conductive shoes (19 ^' , 42 ^' ) mounted in a fixed and lower stator position (11). Both the pair of upper (19.42) and lower (19 ^' , 42 ^' ) conductive shoes are aligned according to the longitudinal extent of the rotor (2) and are adjacent. To ensure electrical insulation between these conductive shoes, there is an insulating plate located between the two conductive plates of each pair, namely a first insulating plate (41) placed between the two upper conductive shoes (12,42), and a second insulating plate (41 ^' ) between the two lower conductive shoes (12 ^' , 42 ^' ).

The conductive shoes (19,42 19 ^' , 42 ^' ) are permanently pressed against the movable contact groups (9,9 ^' , 9 ^" ) or the rotor (2) by means of an elastic means, in this case by means of a pair of upper springs (23) and a pair of lower springs (23 ^' ).

The switch incorporates a pair of fixed contacts, in particular an upper fixed contact (4) in electrical contact only with the conductive shoe (42) and a lower fixed contact (4 ^' ) in electrical contact only with the conductive shoe (19 ^' ) as seen more clearly in figure 8.

As seen in Figure 6, a pair of metal connection terminals (22, 22 ^' ) with plate form, they are used for the electrical connection of the switch with an external circuit. Said terminals (22,22 ^' ) have a plate shape and are arranged in opposite parts of the housing (7.7 ^' ) and are electrically connected with the fixed contacts (4.4 ^' ).

As best seen in Figure 7, the rotor (2) does not have to be completely cylindrical, since in this case the rotor (2) is a cylinder cut by two planes parallel to each other, defining two flat surfaces (33,33 ^' ) and parallel to each other arranged on diametrically opposite sides of the rotor with respect to its axis (x), and two curved surfaces (34,34 ^' ) with the curvature of an arc of circumference, arranged on diametrically opposite sides of the rotor with respect to its X axis).

The ventilation fins (32.32 ^' ) are arranged on said flat surfaces (33.33 ^' ), and extend along the rotor along a line parallel to the axis (x), and also have the additional advantage that they increase the contour line of the rotor and therefore increase the leakage line of the electric arc, so that the electrical insulation is improved by complying with the most demanding regulations regarding insulation, and all this in a small space. To enhance this isolation effect, the rotor (2) also incorporates two channels (35.36 ^' ) that extend along it.

The mobile contacts (9) emerge on both curved surfaces (34.34 ^' ) and have ends with the same curvature. Also in this embodiment of Figure 7, it can be seen that the rotor (2) has a closed front end (37), and an open rear end (38) which is attachable to a suction valve (24) which It causes the arc to be aspirated when the rotor (2) with its movement disengages from the valve in a manner similar to that described in relation to figure 1. The suction valve (24) has a cylindrical shape, and is made of an elastic material and insulator, and is configured to fit tightly inside the rotor (2).

To produce said arc aspiration, the rotor (2) has at least one through hole or opening (40) that communicates the interior with the exterior of the rotor. Alternatively, the rotor (2) of the embodiment of Figures 6 to 8 may be cylindrical, with one or two open ends. Alternatively, the rotor (2) of the embodiment of Figures 6 to 8, can be driven by a mechanism external to the housing (7.7 ^' ) such as that shown in Figure 5, or by a drive mechanism such as that of the embodiment of figure 1.

With the structure and elements described above, the functionality of the electrical switch, as well as the serial-parallel-series connection of the mobile contacts, is obtained in the manner described below with reference to the sequence of figures in Figure 8.

The three groups of mobile contacts (9.9 ^' , 9 ^" ) rotate simultaneously with the rotor (2) defining a helical movement with respect to the axis (X) of rotation of the rotor, so that at the same time they move longitudinally in the shaft direction

(X) (from left to right in the figure), they rotate with respect to that axis. In the position of Figure 8 a, the moving contacts (9.9 ^' , 9 ^" ) are horizontally at an angle of 0 ^or , in an open position (no electrical connection) of the switch. At a later time when They have turned 20 ° Figure 8b, the ends of the moving contacts have approximated the pairs of upper and lower conductive shoes (19,42, 19 ^' , 42 ^' ), but there is still no electrical connection.

At a later time when the mobile contacts (9.9 ^' , 9 ^" ) have turned 30 ° figures 8 cyd, the ends of the mobile contacts (9.9 ^' , 9 ^" ) come into contact respectively with the upper and lower shoes (19, 42, 19 ^' , 42 ^' ) starting the electric conduction as indicated by the arrows in Figure 8c, and so that the three groups of mobile contacts (9.9 ^' , 9 ^" ) are connected in series by the plates (19, 42, 19 ^' , 42 ^' ) so that the electric current would circulate as indicated by the arrows in the figure, that way, at the time of arc arc, it is divided into several cut-off points, specifically in six cut-off points corresponding to the number of ends of the three groups of mobile contacts (9.9 ^' , 9 ^" ), so the arc shutdown is easier.

Specifically, a first end of the first group of mobile contacts (9) is in contact with the shoe (19 ^' ), and a second end of that same contact is in contact with the shoe (19). A first end of the second group of mobile contacts (9 ^' ) is in contact with the shoe (42 ^' ), and a second end of the same contact is in contact with the shoe (19). A first end of the third group of mobile contacts (9 ^" ) is in contact with the shoe (42 ^' ), and a second end of the same contact is in contact with the shoe (42).

The rotor (2) continues to rotate in the same direction, so that the mobile contacts (9.9 ^' , 9 ^" ) advance by sliding respectively on the shoes (19, 42, 19 ^' , 42 ^' ) reaching a turning position 45 ° (figure 8e), in which the mobile contacts are still connected in series, but where the upper end of the second group of mobile contacts (9 ^' ) is very close to the shoe (42). When the mobile contacts arrive at the 60 ° rotation position (figure 8f), the upper end of the second group of mobile contacts (9 ^' ) comes into contact with the shoe (42) and remains in contact with the shoe (19), thereby three groups of mobile contacts (9.9 ^' , 9 ^" ) become connected in parallel, as shown by the arrows in that figure. In the position of figures gyh, the movable contacts have rotated 90 ° and are in a vertical position, in which they remain stable until a switch opening maneuver is performed, and an inverse sequence of movement is initiated.

It can be seen that the change of serial-parallel and parallel-serial connection is obtained by the size of the mobile contacts (9.9 ^' , 9 ^" ) and shoes

(19,42, 19 ^' , 42 ^' ), as well as the relative position between all of them, taking into account the helical displacement of the mobile contacts (9.9 ^' , 9 ^" ).

In the series-parallel transition, the first group of mobile contacts (9) is always connected between the shoes (19,19 ^' ), and the third group of contacts (9 ^" ) is always connected between the shoes (42,42 ^' It is only necessary that the second group of mobile contacts (9 ^' ) change connection, and that it goes from being connected between the shoes (19.42 ^' ) to being connected between the shoes (19.42) and the shoe ( 42 ^' ). Therefore, the switch of the present invention with a simple structure, is capable of reconfiguring the connection of the same internal contacts in two different modes of operation, in order to perform its most critical work which is to cut or open an electric current with the appearance of an electric arc, and connect them in a more optimal way, that is, in parallel when the power cut-off function has ended, to reduce the heating of the switch and energy losses. One of the advantages of the invention is that thanks to the fact that the current cutting process is carried out without impact between parts, materials other than those currently used can be used. Thus, in a preferred embodiment of the invention, the rotor (2) is made of glass, which provides the additional advantage that this material is an excellent insulator of high dielectric strength, and has a high resistance to arc deterioration. electrical, compared to the insulating plastic materials traditionally used in the state of the art, which in turn significantly lengthens the life of the switch. Alternatively, the rotor can also be made of porcelain or other similar insulating materials, obtaining the same advantages discussed above with respect to glass.

It can be seen in view of these figures, that the switch developed in this invention is capable of achieving at the same time and with a single movement at least three effects, namely:

- greater separation between contacts in the cutting process, thanks to the sum of radial and axial displacement of the helical movement of the moving contacts,

- power failure with instant interposition (at the same time of the cut) of a solid insulating material,

- connect contacts in series to increase cutting power,

- and optionally, the possibility of producing the aspiration or suction of the arc into the rotor.

The particular structure of the switch, allows it to have a reduced size, since it is not necessary to have air chambers between contacts, being able to achieve a size reduction of about 50% compared to a conventional switch for the same cutting power.

The operation of the switch does not imply the sudden impact between any of its parts, which increases the life of the switch and increases its reliability

The embodiment represented in the figures corresponds to a single pole switch, that is, unipolar. However, for the person skilled in the art, it is clear that the same structure shown can easily be adapted to implement a multi-pole switch.

The various embodiments and alternatives described herein can be combined with each other, giving rise to other embodiments such as those obtained with the multiple combinations of the appended claims.

Claims

1. - Helical switch comprising: at least one pair of fixed contacts and a movable mobile contact between a closing position of the switch in which it establishes electrical continuity with the fixed contacts, and an opening position in which circulation is prevented of current, characterized in that it further comprises a rotor of insulating material, and wherein said at least one mobile contact is mounted on the rotor, where the rotor is movable defining a helical movement on a rotation axis between a closed position and a position of electrical breaker of the switch.

2. - Helical switch according to claim 1, wherein the rotor is elongated with respect to its axis of rotation, and the at least one mobile contact is configured so that it has two ends accessible by different points on the outer surface of the rotor.

3. - Helical switch according to claim 1 or 2, wherein at least one pair of fixed contacts have a contact surface arranged to be contacted by a mobile contact, and where the rotor is configured so that in the position of Opening the switch, the rotor is in direct contact with the fixed contacts and covers a majority of the contact surface of the fixed contacts.

4. - Helical switch according to any of the preceding claims, further comprising a stator that includes a housing of insulating material, wherein said fixed contacts are mounted on said stator, and where the rotor is housed within the stator, and where the stator and The rotor is configured to form a complementary threaded coupling between the two, to produce the helical displacement of the rotor, reciprocally between the closing and opening positions of the switch.

5. - Helical switch according to any of the preceding claims, wherein the The stator has a cylindrical chamber in which the rotor is housed, where the rotor is at least partially hollow, and where the stator and the rotor have ventilation windows positioned so that, in the electric closing position of the switch, they overlap defining a ventilation channel that communicates the inside of the rotor with the outside of the stator.

6. - Helical switch according to any of the preceding claims, wherein the rotor has at least two openings located at diametrically opposite points of its outer surface, and where the mobile contact is one or more superimposed metal plates, housed in the rotor, of so that the two ends of the moving contact emerge through said rotor openings, and are arranged to contact the corresponding fixed contacts in the switch closed position.

7. - Helical switch according to any of the preceding claims, which further comprises at least one ring of insulating material, integrally mounted in the cylindrical chamber of the stator, so that the rotor slides on said rings, and because the movable contacts are arranged so that in the position of electric cut, its free ends face an insulating ring.

8. Helical switch according to any of the preceding claims, which further comprises two or more mobile contacts mounted on the rotor, and one or more conductive shoes outside the rotor, the shoes being arranged so that in the electric closing position of the switch connect the mobile contacts in series between the fixed contacts.

9. Helical switch according to any of the preceding claims, wherein the rotor has a through hole 22 that communicates the inside with the outside of the rotor, and because it has suction means arranged to cause suction inside the rotor, in order of sucking the electric arc into the rotor with its displacement.

10. Helical switch according to claim 9, wherein said suction means comprise at least one shut-off valve arranged facing an open end of the rotor, wherein said valve is adapted to slide in the inside the rotor to cause suction.

11. - Helical switch according to any of the preceding claims, wherein the rotor is made of glass or porcelain.

12. - Helical switch according to any of the preceding claims, further comprising: at least two mobile contacts mounted on the rotor, wherein each mobile contact is configured so that it has two ends accessible by different points on the outer surface of the rotor, and where the movable contacts are placed in the rotor at a different axial dimension with respect to the rotor axis, a first pair of conductive shoes arranged adjacent to each other and aligned according to the longitudinal extension of the rotor, and arranged to be contacted by a first end of the movable contacts, and where one of these shoes is connected to a first fixed contact of the switch, a second pair of conductive shoes arranged adjacent to each other and aligned according to the longitudinal extension of the rotor, and arranged to be contacted by a second end of the mobile contacts, and where one of these shoes is connected with an s second fixed contact of the switch, where the movable contacts and the shoes are positioned relative to each other in such a way, that as the rotor moves axially, in a first axial position of the rotor, the movable contacts are connected to each other in series to through the shoes, and in a second axial position of the rotor the moving contacts of the rotor are connected to each other in parallel through the shoes.

13. - Helical switch according to any of the preceding claims, wherein the rotor is configured so that it has two flat and parallel surfaces arranged on diametrically opposite sides of the rotor with respect to its axis, and because it incorporates cylindrical sector through which it supports and slide relative to the stator.

14. - Helical switch according to claim 13 wherein the rotor incorporates emerging ventilation fins of said flat surfaces.

15. - Helical switch according to any of the preceding claims 1 to 3 and / or 5 to 14, which incorporates an external body to the housing, and because the rotor has a part housed within that external body and is rotatable thereon by a threaded coupling complementary to both elements to produce the helical movement of the rotor.