EP1745533A1 - Surge voltage protection device with improved disconnection and visual indication means - Google Patents

Abstract

A device for protecting an electrical system against surge voltages, comprising one or more protection components (10), means (20) for disconnecting the protection component (10) and means (30) for visually indicating the state of said component (10), operationally connected to the disconnection means (20) and comprising at least one control part (40) and at least one means (50) for indicating the state of the protection component (10), combined with said control part (40), characterised in that the relative arrangement of said control part (40) and said disconnection means (20) is such that, when the latter are opened (20), they release the control part (40), thereby allowing it to move. Electrical surge voltage protection devices are also described.

Description

 SURGE PROTECTION DEVICE WITH IMPROVED DISCONNECTION AND VISUALIZATION MEANS

TECHNICAL AREA

The present invention relates to the general technical field of devices for protecting electrical installations and equipment against transient electrical overvoltages.

The present invention relates more particularly to a device for protecting an electrical installation against overvoltage comprising: - at least one protection component, - means for disconnecting the protection component, adapted to disconnect the latter from the electrical installation, and capable of moving between a closed position, in which the protective component is connected, and an open position, in which the protective component is disconnected, - means for viewing the state of the protective component, connected functionally with the disconnection means and comprising: - at least one control part, distinct from the disconnection means and able to move under the dependence of the latter, - at least one means for indicating the state of the protection component, associated with the control panel in such a way that the indicating means indicates, depending on the position of the control part, if the protective component is in service or disconnected.

PRIOR ART

Protection devices for electrical installations are commonly used to protect in particular electrical or electronic devices against overvoltages which may, for example, be generated by discharges due to lightning.

These devices generally comprise an active part formed by one or more protective components, such as for example a varistor or a spark gap.

Varistors are components commonly used to protect electrical installations or equipment against transient overvoltages.

When an overvoltage occurs within the installation, the varistor undergoes a current shock which has the effect of degrading it and causing it to heat up, making it necessary to disconnect it thermally.

The deterioration of the varistor is difficult, if not impossible to predict, insofar as it depends not only on the number of current shocks undergone by the varistor during its life, but also on their amplitude.

It is therefore difficult to predict a priori the service life and the degree of aging of a varistor and the user is often led to observe a posteriori the destruction of the latter, so that the installation runs the risk of operating for a certain latency period without protection.

In order to allow rapid identification of a defective varistor and to reduce the latency time mentioned above, it is known to equip each varistor with display means capable of indicating to a third party that the varistor is out of service.

The varistors generally encountered are thus associated with disconnection means suitable for disconnecting the varistor when it is in a degraded state and before it heats up excessively, to which the display means of the function are connected functionally. state of the varistor, generally actuated by the disconnection means, and which make it possible to indicate to a third party whether the varistor is in service or disconnected.

The display means can thus take the form of a cursor associated with a display piece and able to move in translation under the action of the disconnection means, so as to indicate, depending on its position, the state of the varistor and this, by placing the display piece opposite, for example a colored screen, with a display window formed in the housing of the protection device.

In known protection devices, the cursor and the display part are either secured to the disconnection means, in particular a disconnection blade, or independent while being controlled and actuated by the latter.

In all cases, the displacement of the disconnection means towards their open position generates the displacement of the cursor, displacement controlled or even guided by the disconnection means or independent guidance means.

However, it may happen that the cursor or the display part is hindered in its movement, in particular in the case where the cursor and / or the display part are badly dimensioned or even if the guide means are defective, leading thus to a bad guidance of the cursor.

In this situation, the cursor and / or the display part can then hinder or even prevent the disconnection of the varistor. The latter then remains connected and the display means do not indicate any anomaly while the varistor is greatly degraded, and may cause a fire due to its heating.

In addition, the assemblies in which the cursor, and / or the display part are actuated and their movement controlled by the disconnection means generally require perfecting of the dimensioning of the parts, so as on the one hand to avoid the formation of clearances between the latter, and on the other hand to avoid any risk of blockage of the disconnection and / or display system.

In addition, in order to prevent the cursor and / or the display part from braking disconnection, the disconnection blades are generally designed so as to have a significant spring effect, such as to compensate for the braking effect possibly exerted by the cursor and / or the display part.

However, such a measure has the drawback of weakening the connection by welding between the disconnection blade and the corresponding electrode of the varistor. In general, the mechanical complexity of the known devices requires perfect control of the parts manufacturing operations, which has the effect of significantly increasing the cost of manufacturing the devices.

The preceding remarks obviously apply to devices implementing other protective components, in particular spark gaps for which it may prove necessary, in certain applications, to use thermal disconnectors.

We therefore see the advantage of producing a protection device against overvoltages, which while falling within a simple and economical design, is capable of disconnecting, in the most reliable and efficient way possible, the protection component of the installation to be protected, and at the same time to indicate to a third party that the same protection component is out of service.

STATEMENT OF THE INVENTION

The objects assigned to the invention therefore aim to remedy the various drawbacks listed above and to propose a new device for protecting electrical installations against overvoltages which ensures a particularly reliable and rapid disconnection of the protection component.

Another object of the invention is to propose a new device for protecting electrical installations against overvoltages which is capable of indicating in a simple, reliable and instantaneous manner the state of the protection component. Another object of the invention is to propose a new device for protecting electrical installations against overvoltages, the design of which is particularly simple and economical.

Another object of the invention is to propose a new device for protecting electrical installations against overvoltages requiring only a limited number of parts to obtain the connection / disconnection function on the one hand, and display on the other hand go.

Another object of the invention is to propose a new device for protecting electrical installations against overvoltages allowing the simultaneous and differentiated display of the state of several protection components connected in parallel.

Another object of the invention is to propose a new device for protecting electrical installations against overvoltages making it possible to provide a remote indication of the state of the protection component.

The objects assigned to the invention are achieved by means of a device for protecting an electrical installation against overvoltage comprising: - at least one protection component, - means for disconnecting the protection component, suitable for disconnecting the latter of the electrical installation, and capable of moving between a closed position, in which the protective component is connected, and an open position, in which the protective component is disconnected, - display means for the state of the protection component, functionally connected to the disconnection means, and comprising: - at least one control part, separate from the disconnection means and able to move under the dependence of the latter, - at least one means for indicating the state of the protection component, associated with the control part of such so that the indicating means indicates, depending on the position of the control piece, whether the protective component is in service or disconnected, characterized in that the control piece and the disconnection means are arranged relatively in such a way that when opening the disconnection means, the latter release the control part, thereby authorizing the displacement of the latter.

SUMMARY OF DRAWINGS

Other particularities and advantages of the invention will appear and will go into greater detail on reading the description given below, with reference to the appended drawings, given purely by way of non-limiting illustration, in which:

- Figure 1 illustrates, in a sectional view, a surge protection device according to the invention when the protection component is in service.

- Figure 2 illustrates, in a sectional view, the protection device shown in Figure 1 when the connection component is disconnected.

- Figure 3 illustrates, in a perspective view, a protection device according to the invention provided with two varistors mounted in parallel. - Figures 4a, 4b, 4c illustrate, in a schematic view, a system for displaying the state of two varistors mounted in parallel when the two varistors are in service (Figure 4a), when only one of the varistors is in service (Figure 4b) or when the two varistors are disconnected (Figure 4c).

- Figures 5a, 5b, 5c illustrate, in a schematic view, an improved variant of the display system of the state of two varistors mounted in parallel when the two varistors are in service (Figure 5a), when only one of the varistors is in service (Figure 5b) or when the two varistors are disconnected (Figure 5c).

- Figures 6a, 6b, 6c illustrate, in a schematic view, a variant of protection device according to the invention, in which the device is adapted to be connected to a remote signaling system, the figures illustrating the two states following: a first state where the two varistors are in service (FIG. 6a) and a second state where only one of the varistors is in service (FIGS. 6b and 6c).

- Figure 7 illustrates, in a perspective view, a base on which is intended to be inserted a protective cell according to the invention.

- Figure 8 illustrates, in a perspective view, a preferred embodiment of the protection device according to the invention, combining a direct display member and a remote signage indicator.

BEST WAY TO IMPLEMENT THE INVENTION

The overvoltage protection device according to the invention is intended to be connected bypass to the equipment or the installation. electric to protect. The expression “electrical installation” refers to any type of device or network likely to be subjected to voltage disturbances, in particular transient overvoltages due to lightning. In the latter case, it is therefore formed by a surge arrester.

The overvoltage protection device according to the invention is advantageously intended to be disposed between a phase of the installation to be protected and the earth.

It is also conceivable, without departing from the scope of the invention, that the device, instead of being connected in bypass between a phase and the earth, be connected between the neutral and the earth, between the phase and the neutral, or between two phases (in the case of differential protection).

The protection device comprises at least one protection component 10 forming the active part, for example of a lightning arrester, intended to protect the electrical installation.

In the following description, it is considered that each protective component 10 present in the device is formed by a varistor, it being understood that the use of a varistor is indicated only by way of example and does not constitute in no way a limitation of the invention.

The protection device according to the invention comprises at least one varistor 10, for example one or two varistors 10, disconnection means 20 for each varistor, sensitive to their degree of aging and adapted to disconnect each varistor from the installation individually electric when the varistors are in a degraded state. The protection device according to the invention also comprises means 30 for viewing the state of each varistor 10, functionally connected to the disconnection means 20.

Advantageously, the protection device is formed by a protection cell 1 which may include one or more modules 2 each containing a varistor 10 (Figures 1, 2 and 3). Each module 2 advantageously comprises a base 3 made of electrically insulating material, a varistor 10, two electrically conductive electrodes 4, constituting the poles of the varistor 10 as well as disconnection means 20.

In the withdrawable versions of the device illustrated in Figures 1 and 2, each module 2 is adapted to be electrically connected to a base 400 (Figure 7) using connection pads 8, 9 intended to be introduced into orifices 405 , 406 provided on the base 400.

Thus, one of the poles of the varistor 10 is connected directly to a connection pad 8, the other pole of the varistor being connected to an electrode 4, which is welded to the connection means 20 which are in permanent electrical contact with the other connection pad 9.

The disconnection means 20 are preferably formed by a thermal disconnector, such as for example a disconnection blade 21 in thermal and electrical contact with the associated varistor 10, so that heating of the varistor, linked to the arrival at the end life of the latter, causes the opening of the disconnection blade 21, thus isolating the varistor from the lines to be protected.

The disconnection means 20 are thus capable of moving between a so-called closed position, in which the varistor 10 is connected to the network or to the electrical installation and an open position, in which varistor 10 is disconnected from the electrical installation. These two positions are illustrated in FIGS. 1 and 2.

Advantageously, the disconnection blade 21 extends between two ends 21 A, 21 B, one of the ends 21 A is preferably fixed using a hot-melt weld on one of the electrodes 4. The end 21 A of the disconnection blade 21 is thus preferably welded under stress, so that when the varistor 10 reaches the end of its life, it heats up and causes the fusion or the rupture of the weld which, once broken, allows the release of the disconnection blade 21.

Thanks to its intrinsic elasticity, the disconnection blade 21, precisely the end 21 A of the disconnection blade 21 then moves away from the electrode 4, while the other end 21 B remains fixed, as shown in figure 2.

We will now describe in detail the structure of the display means 30.

The display means 30 are adapted to inform a third of the state of the varistor (s) contained in the protection cell 1. These display means 30 are functionally connected to the disconnection means 20, that is to say that there are intermediate means making it possible to link the position of the disconnection means 20 to the indication provided by the display means 30.

According to the invention, the display means 30 comprise, for each protection cell 1, a control part 40, distinct from the disconnection means 20 and able to move under the dependence of the latter. This control piece 40 advantageously ensures the connection functional between the disconnection means 20 and the display means 30.

The display means 30 also comprise means 50 for indicating the state of the varistor 10 associated with the control piece 40, so that the indication means 50 indicates, as a function of the position of the piece of command 40, if varistor 10 is in service or disconnected.

According to the invention, the control piece 40 and the disconnection means 20 are arranged relatively in such a way that when the disconnection means 20 open, the latter release the control piece 40 thus allowing free movement, it that is to say, not controlled by the disconnection means 20, of the latter.

Once released, the control part 40 is thus free to move, that is to say that it is neither actuated nor guided in movement by the disconnection means 20.

In a particularly advantageous manner, the disconnection means 20 are, in their closed position, mounted so as to form a stop against the control part 40. Thus, the control part 40 advantageously comprises a support zone 40A which , when the disconnection means 20 are in their closed position, bears against the latter (FIG. 1).

The disconnection blade 21 therefore has a triple function: - in normal operation, it serves for the electrical connection of the varistor 10, - at the end of the life of the varistor 10, it serves to disconnect the latter, - finally, it also serves to release the display means 30 thus leading to a change in indication of the state of the varistor 10.

Advantageously, the control piece 40 and the disconnection means 20 are arranged so that when the disconnection means 20 are in their closed position (FIG. 1), the control piece 40 is elastically stressed and comes to bear, in particular by means of the support zone 40A, against the disconnection means 20, and thus exerts on the latter a driving stress tending to push them back towards their open position.

The display means 30 therefore assume a dual function: - on the one hand, they make it possible, via the indication means 50, to provide an indication of the state of the varistor 10, - and on the other hand , they participate, through the control part 40, in the disconnection of the varistor 10 by forcing the disconnection means 20, in particular the disconnection blade 21, towards their open position.

Such an assembly therefore makes it possible to anticipate and secure the disconnection of the protection component. It also makes it possible to use a disconnection blade 21 having a moderate spring effect and therefore to reduce the risks of mechanical embrittlement of the thermal disconnection weld.

The design of the protection device according to the invention and in particular the mounting of the display means 30 of the state of the varistor allows thus, thanks to the small number of parts cooperating together and the limited number of points of contact between these parts to ensure rapid and reliable disconnection of the protective component. This reliability is further accentuated by the fact that the display means 30 are distinct from the disconnection means 20.

In addition, thanks to the simultaneous or almost simultaneous movement of the display means 30 and the disconnection means 20, a third party can very quickly perceive that a varistor is disconnected.

In a particularly advantageous manner, and as shown in FIGS. 1, 2, the control part 40 is formed by a cursor 41, made of electrically insulating material, able to move in a substantially rectilinear direction F.

Advantageously, the front part 41 A of the cursor 41 is specifically designed to come into abutment against the disconnection means 20, on the one hand when the latter are in their closed position and on the other hand, when these last, so that the cursor 41 is permanently in contact with the disconnection means 20.

According to the variant embodiment of the invention shown in FIGS. 1 and 2, the display means 30 are advantageously formed by mechanical means mounted in a housing 60, which also contains the varistor 10.

In a particularly advantageous manner, the display means 30 also comprise an elastic means 70, of the spring type, adapted to exert a restoring force on the control part 40 responsible for the movement of the latter. As shown in Figures 1 and 2, the elastic means 70 is preferably interposed between on the one hand the control piece 40, against which it abuts and on the other hand a fixed stop, for example formed by one of the interior walls of the housing 60.

The elastic means 70 is thus advantageously adapted to occupy a compressed position when the control part 40 is stressed longitudinally, that is to say in a direction substantially parallel to the direction of movement F and a rest position, when the part 40 is released from the disconnection means 20 (Figure 2). The elastic means 70 thus constitutes a means of pre-stressing the control part 40.

According to the embodiment illustrated in FIGS. 1 and 2, the cursor 41 extends longitudinally in the direction F, and is preferably sufficiently rigid so that its front part 41 A can come to bear firmly against the disconnection means 20 and more particularly against the end 21 A of the disconnection blade 21.

When the weld breaks, for example under the effect of heating of the varistor 10, the end 21 A of the disconnection blade 21 moves in the direction F and therefore no longer constitutes an obstacle or a stop against the workpiece 40. The elastic means 70, initially compressed, then tends to relax (FIG. 2) thus causing the displacement of the cursor 41 in the direction F. By moving, the cursor 41, still pressing against the end 21 A of the disconnection blade 21, tends to force the latter towards its open position, thus actively participating in the disconnection of the protective component. In a particularly advantageous manner, the restoring force exerted by the elastic means 70 on the end 21 A of the disconnection blade 21 will preferably be greater than the resistance opposed by the blade disconnection 21, in order to force the latter to move further away from the electrode 4.

According to this embodiment of the invention, the indication means 50 is advantageously formed by a display member, preferably by a panel 51, for example rectangular, preferably placed on the cursor 41. The panel 51 can be formed by a piece of insulating plastic material, for example glued to the cursor 41, but can also be simply formed by a colored strip painted on the cursor 41. The panel 51 is more advantageously arranged so as to move at the same time as the control part 40 opposite a window 61 formed in one of the faces 60B of the housing 60 situated opposite the base 3, in order to obtain a different visual appearance through the window 61, depending on the position of the control part 40.

Thus, when the disconnection means 20 are in the closed position (FIG. 1), the elastic means 70 is compressed and the panel 51 is in a position offset from the window 61 and therefore cannot, in this configuration, be viewed from the outside. We then visualize, by looking through the window 61, the cursor 41 which can have, for example, an appearance of green color, by indicating to third parties that the varistor is in service.

On the contrary, when the disconnection means 20 are in the open position as shown in FIG. 2, the panel 51 is in the field of the window 61. It is then capable of being viewed from the outside and presents preferably a colored appearance, for example red, indicating to third parties that the varistor is disconnected.

According to a second embodiment of the invention, shown in FIG. 3, the device comprises a protection cell 1 comprising a first and second varistor 10 mounted in parallel and associated respectively with first and second disconnection means 20A, 20B.

According to this embodiment, the display means 30 are preferably functionally connected to the first and second disconnection means 20A, 20B so as to provide a differentiated indication of the state of each varistor 10 taken individually (FIGS. 4a, 4b, 4c).

According to this embodiment, the control part 40 is preferably formed by a cursor 41, provided with a front part 41 A, mounted resiliently movable between: an initial position (FIG. 4a), corresponding to a connected state of the two components protection, in which the cursor 41 is held in position simultaneously by the two connection means 20A, 20B, its front part 41 A coming to bear against the latter, - an intermediate position (FIG. 4b) offset from the initial position , corresponding to a state where only one of the disconnection means 20A, 20B is disconnected, in which the cursor 41 is held in position by the disconnection means 20A in the closed position, - and a final position (FIG. 4c) offset from at the intermediate position, corresponding to a state disconnected from the two disconnection means 20A, 20B. In this final position, the cursor 41 is not necessarily held in position by the disconnection means 20A, 20B but can come into abutment against the latter, as shown in FIG. 4c. According to this embodiment of the invention, the indication means 50 is preferably formed by a display member, preferably a panel 51 mounted on or made of material with the cursor 41 and preferably arranged towards the end opposite to the front part 41 A so as to move opposite the viewing window 61.

The panel 51 is preferably divided into two zones 51 A, 51 B arranged so that when the disconnection means 20A, 20B are in the closed position (FIG. 4a), the zone 51 A, preferably colored in green, is substantially in viewing window 61. In this way, the window appears green, indicating that the protection components are in service. On the contrary, when the two disconnection means 20A, 20B are in the open position (FIG. 4c), it is the other zone 51 B, preferably colored in red, which is located opposite the window 61. In this configuration, window 61 appears red, indicating that the two varistors are disconnected. In the intermediate position illustrated in FIG. 4b, the window 61 is simultaneously occupied by at least part of each of the two zones 51 A, 51 B so that part, for example half of its surface, appears red, l other part or half appearing green. The visual appearance of window 61 therefore indicates to third parties that only one varistor is disconnected.

The amplitude of movement of the cursor 41 is therefore adjusted so as to generate a different visual appearance through the window 61 according to the configuration of the disconnection means 20A, 20B.

According to the embodiment illustrated in FIGS. 4a, 4b and 4c, the cursor 41 is elastically constrained by an elastic means 70 forcing it to come into abutment, via its front part 41 A, against the disconnection means 20A , 20B (Figure 4a). In a particularly advantageous manner, the control part 40, precisely the cursor 41, comprises two stages of support zone 42, 43 arranged one behind the other in the direction of movement F of the control part 40 so as to block the latter successively in the two initial and intermediate positions. The structure of the control part 40 thus makes it possible to generate a stepwise displacement of the latter between the different initial, intermediate and final positions.

Even more preferably, the control piece 40 comprises a pair of so-called downstream support zones 42A, 42B intended to come into abutment, in the initial position (FIG. 4a), against the two disconnection means 20A, 20B.

The control part 40 also comprises a pair of so-called upstream support zones 43A, 43B, arranged upstream of the first pair of downstream support zones 42A, 42B opposite the direction of movement F of the control part 40, such that in the intermediate position (FIG. 4b), one of the upstream support zones 43A comes into abutment against the corresponding disconnection means 20A in the closed position.

Obviously, if the opening of the other disconnection means 20B had taken place first, it is the other upstream support zone 43B which would have come into abutment against the corresponding disconnection means 20B.

In this configuration, the display means 30 advantageously have a symmetry with respect to the plane S delimiting the separation between the two varistors.

In a particularly advantageous manner, the upstream support zones 43A, 43B are preferably formed by fingers 44 projecting from one side and on the other side of the control piece 40 and extending in a direction substantially perpendicular to the main direction F of movement of the control piece 40.

Preferably, the device comprises means for guiding the movement of the control part 40, adapted to allow an angular movement of the latter so as to allow, when one of the disconnection means 20A, 20B is opened, the crossing of the other disconnection means 20A, 20B, by the corresponding downstream support zone 42A, 42B. The moving guide means can advantageously be formed by the side walls 60C, 60D of the housing 60. The cursor 41 is then advantageously disposed within the housing 60 so as to maintain sufficient clearance between the contours of the cursor 41 and the walls 60C , 60D to allow angular travel.

Thus, to pass from the initial position shown in FIG. 4a to the intermediate position shown in FIG. 4b, the cursor 41 must pass through one of the disconnection means 20A which has remained in the closed position, and for this must operate a slight rotation an angle a allowing it to disengage from the disconnection means 20A. The cursor 41 can then continue its travel until the upstream support zone 43A comes into abutment against the disconnection means 20A.

To further facilitate the crossing of the disconnection means 20A remaining in the closed position by the cursor 41, the latter is provided with release means 45. The release means 45 are preferably formed by oblique cutouts, formed on either side other of the cursor 41, at its front part 41 A, said cutouts thus forming the downstream support zones 42A, 42B. In the same way as in the embodiment previously described and illustrated in FIGS. 1 and 2, the elastic means 70 also makes it possible to anticipate and secure the disconnection of the varistors, by ensuring the support under stress of the front part. 41 A of the cursor 41 against the disconnection means 20A, 20B.

Another embodiment of the invention will now be described with reference to Figures 5a, 5b, 5c.

According to this embodiment, the display means 30 advantageously comprise guide means 80 adapted to ensure the movement of the control piece 40 along a predetermined path formed by the combination of a rotational movement and a movement of translation.

The control piece 40 is elastically constrained by means of the elastic means 70 interposed between on the one hand the control piece 40 and on the other hand a stop 62 fixedly mounted within the housing 60.

Under the action of the elastic means 70, of the spring type, the control part 40 comes to bear against the disconnection means 20A, 20B. The control piece 40 for this purpose comprises two end portions 46A, 46B for example in the form of projecting studs, adapted to bear against each of the disconnection means 20A, 20B when the latter are in the closed position (FIG. 5a ).

The guide means 80 of the control piece 40 are advantageously formed by a lug 81, preferably disposed on the control piece 40, and a corresponding groove 82, preferably V-shaped, within which the lug 81 is likely to move when the control piece 40 passes successively through the different initial, intermediate and final positions illustrated in FIGS. 5a, 5b and 5c.

The operation of this alternative embodiment is as follows.

In the initial position illustrated in FIG. 5a, the control part 40 is in stable equilibrium and interposed between the elastic means 70 on the one hand and the disconnection means 20A, 20B on the other hand.

When one of the disconnection means 20B comes to the open position, it at least partially releases the control part 40 which is then liable to move in rotation at an angle β until it comes into contact with one of the walls 60D of the housing 60, as illustrated in FIG. 5b.

In this intermediate position, the control part 40 is also in a stable position and always comes into elastic abutment against the other disconnection means 20A, by means of its end part 46A. The movement of the control piece 40 between the initial position (FIG. 5a) and the intermediate position (FIG. 5b) follows a predetermined trajectory, directly linked to the path of the lug 81 within the groove 82.

According to this embodiment, the indication means 50 is preferably formed by a display member, such as a display panel 51 preferably arranged at one end of the control piece 40 so as to move in view of the window 61 made in the housing 60. Thus, in the initial position shown in FIG. 5a, the display panel 51, preferably colored in green, is located substantially opposite the window 61 thus indicating that all the varistors are connected. In the intermediate position illustrated in FIG. 5b, the control part 40 is angularly offset from its initial position, so that the display panel 51 is also offset from the window 61. The latter then has an appearance different display, indicating that one of the varistors is disconnected. By way of example, and as shown in FIG. 5b, part of the viewing window 61 can remain hidden by the control part 40, thus indicating to third parties that only part of the protection components is disconnected.

When the other disconnection means 20A in turn passes into the open position, the control part 40, under the action of the elastic means 70, tends to move in a direction F substantially rectilinear which has the effect of releasing completely the viewing window 61 which then has a homogeneous visual appearance, for example red, indicating that all the protective components are disconnected and that they must be replaced.

The movement of the control piece 40 between the intermediate and final positions is guided by the cooperation of the lug 81 with the groove 82, the lug 81 moving in a substantially rectilinear manner in one of the branches of the V formed by the throat 82.

Such an arrangement has the advantage of not hampering disconnection in the event of blockage of the display means 30.

Another advantage of this arrangement is that it also makes it possible to participate in the disconnection by means of the elastic means 70 which, by exerting a thrust on the control part 40, promotes the displacement of the disconnection means 20A, 20B at the time of the weld fusion. Another advantage of this arrangement is that it is not very sensitive to vibrations or shocks likely to occur, for example during transport operations, the control part 40 always being able to return to its initial position under the effect of force. of return exerted by the elastic means 70.

According to another embodiment of the invention illustrated in FIGS. 6a, 6b and 6c, the indication means 50 is formed by a remote indicator (not shown) operatively connected to the control part 40 by means of a remote signaling system. The indication means 50 can thus be formed by a visual, auditory indicator or any other type of sensory indicator.

On the other hand, unlike the various embodiments previously described, the indication means 50 is not mechanically connected to the control part 40, but offset, that is to say it is connected to the latter by d '' means other than mechanical means, in particular by remote signaling. Thus, the indicator is not located in the immediate vicinity of the housing 60 but at a significant distance from the latter.

This variant embodiment of the device is shown in the case of two varistors mounted in parallel but can obviously apply to devices having only one varistor.

According to this embodiment, the control piece 40 is secured with two pins 52, 53 intended to engage in corresponding housings 401, 402 formed in a base 400 (FIG. 7) intended to receive the protection cell 1. As is well known to those skilled in the art, the pins 52, 53 are intended to cooperate with a mechanism disposed within the base 400, capable of triggering a mini-breaker, and thus signaling changes in status of the device to third parties located at distance from the housing 60. Thus, when the two pins 52, 53 are in a low position corresponding to a state where the two varistors are connected (FIG. 6a), the mechanism and the associated remote signaling system provide a remote signal indicating that the two varistors of the device are connected.

On the contrary, when one of the varistors is disconnected, as illustrated in FIG. 6c, the two pins 52, 53 pass in the high position, thus generating electrical signals capable of indicating at a distance that at least one varistors of the device is disconnected.

According to a particularly advantageous characteristic of the invention, the control piece 40 is secured to the pins 52, 53 so that its movement causes at the same time a substantially identical movement of the pins 52, 53 within passages 62, 63 formed in the bottom wall 60A of the housing 60.

In a particularly advantageous manner, the control piece 40 can be formed by a slider, and is preferably in the form of an elongated rod provided with a front part 40A in the form of a disc or sphere intended to come into abutment against a fold 20C formed in the disconnection means 20A, 20B, and designed to form a stop against the control part 40.

When they are opened, the disconnection means 20A, 20B release the control part 40, thus authorizing the free movement of the latter. On the contrary, when the disconnection means 20A, 20B are in the closed positions (FIG. 6a), the control part 40 is forced between on the one hand the elastic means 70, tending to push it back in the direction F, and on the other hand the disconnection means 20A, 20B, precisely the folds 20C formed in the latter. The folds 20C preferably extend along a plane substantially perpendicular to the plane of extension of the disconnection blades 21. Even more preferably, the folds 20C can extend obliquely relative to the blades of the disconnections 21, so that the front part 40A of the control piece 40 exerts on the latter a driving stress tending to push the disconnection blades 21 towards their open position.

The control part 40 and the associated elastic means 70 then constitute means for assisting in the disconnection of the protection components of the device.

In a particularly advantageous manner, the control part 40 is flexible enough to allow an angular movement of its front part 40A. Indeed, as shown in Figures 6a, 6b and 6c, the folds 20C formed in the disconnection means 20A, 20b protrude so as to form stops against the front portion 40A of the control part 40. Consequently, when one of the disconnection means 20A passes into the open position, the control part 40, precisely the front part 40A of the latter must disengage from the projecting part of the fold 20C of the disconnection means 20B remained in the closed position, so as to cross the latter. The lateral flexibility of the control part 40 then allows sufficient angular movement of its front part 40A so that the latter can pass, under the action of the elastic means 70, the stop formed by the fold 20C. In a particularly advantageous manner, the control piece 40 has a narrowing of section 48, giving it its flexible character.

The operating principle of the device will now be specified with reference to Figures 6a, 6b, 6c. When the two disconnection means 20A, 20B, specifically the disconnection blades 21 are in the closed position as illustrated in FIG. 6a, the control part 40 is advantageously elastically stressed between the elastic means 70 on the one hand, and the disconnection means 20A, 20B, precisely the stops formed by the folds 20C on the other hand. As soon as one of the disconnection means 20A, 20B opens, for example the disconnection means 20A, the control part 40 is released, and moved in movement under the action of the elastic means 70. The control part 40 is then likely to move in the main direction F with a slight angular offset y so as to disengage from the disconnection means 20B which remains in the closed position and whose fold 20C protrudes against the front part 40A of the workpiece. control 40. Once this obstacle has been crossed, the control part 40 is free to move towards its final position illustrated in FIG. 6c.

When it moves from the initial position to the final position, the control part 40 simultaneously drives the pins 52, 53 out of their housings 401, 402 within the base 400, thus triggering the command of a new signal to distance indicating that at least one of the varistors of the device is disconnected.

According to an even more preferred embodiment of the invention, illustrated in FIG. 8, the device comprises several display means, namely direct display means and remote display means.

To this end, the device comprises a first control part 403, associated with a direct display member of the display panel 51 type, as well as a second control part 404, associated with a remote descriptive indicator (not shown), the first and the second control parts 403, 404 being adapted to cooperate independently of one another with the disconnection means 20A, 20B. Thus, the assembly associating the first control part 403 with the direct display member could of the type be illustrated in FIGS. 1, 2, 4a, 4b, 4c, 5a, 5b, 5c. As for the assembly associating the second control part 404 with a remote descriptive indicator, it may be of the type shown in FIGS. 6a, 6b, 6c.

According to this variant embodiment of the invention, the opening of the disconnection means 20A, 20B causes the first and second control parts 403, 404 to be released almost simultaneously, thus indicating that at least one varistor is disconnected, and this on the one hand through the display panel 51 and on the other hand via the remote descriptive indicator.

Such a device therefore makes it possible to associate, within the same housing 60, two separate control parts 403, 404, and capable of actuating two means of complementary indication of the state of the protection components, namely a means proximity indication, for example in the form of a display panel 51, and a remote indication means, advantageously in the form of a remote signage indicator, for example visual or audible.

The protection device according to the invention therefore makes it possible, thanks to a particularly simple mounting of the display means 30 to ensure not only a reliable and efficient disconnection of the varistors when the latter are in a degraded state, but also to simultaneously allow to a third party to visualize the state of these varistors, and this by limiting the risk of the mechanism seizing up or even possible parts guiding problems. 19

Indeed, due to the small contact surface between the functional parts, the risk of blocking of one part by another is significantly reduced.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its application in electrical devices for protection against transient overvoltages.

Claims

- Device for protecting an electrical installation against overvoltages comprising: - at least one protection component (10), - means for disconnecting (20, 20A, 20B) from the protection component (10), adapted to disconnect the latter of the electrical installation, and capable of moving between a closed position, in which the protective component (10) is connected, and an open position, in which the protective component (10) is disconnected, - display means (30) of the state of the protection component (10), functionally connected to the disconnection means (20, 20A, 20B) and comprising: - at least one control part (40), distinct from the disconnection means (20, 20A, 20B) and able to move under the dependence of the latter, - at least one means for indicating (50) the state of the protective component (10), associated with the control part (40 ) in such a way that the indicating means (50) indicates, in depending on the position of the control piece (40), if the protective component (10) is in service or disconnected, characterized in that the control piece (40) and the disconnection means (20, 20A, 20B) are arranged relatively in such a way that when the disconnection means (20, 20A, 20B) are opened, these the latter release the control part (40), thereby authorizing the displacement of the latter. - Device according to claim 1 characterized in that in their closed position, the disconnection means (20, 20A, 20B) are mounted so as to form a stop against the control part (40). - Device according to claim 1 or 2 characterized in that the control part (40) and the disconnection means (20, 20A, 20B) are arranged so that when the disconnection means (20, 20A, 20B) are in their closed position, the control part (40) is elastically constrained and comes to bear against the disconnection means (20, 20A, 20B), thus exerting on the latter a driving stress tending to push them back towards their position of opening. - Device according to one of claims 1 to 3 characterized in that the control part (40) is formed by a cursor (41) capable of moving in a substantially rectilinear direction (F) and whose front part (41 A ) is designed to bear against the disconnection means (20,20A, 20B). - Device according to claim 3 or 4 characterized in that the display means (30) comprise an elastic means (70) adapted to exert a restoring force on the control part (40) responsible for the movement of the latter. - Device according to one of claims 1 to 5 characterized in that it comprises two protection components (10) mounted in parallel, each provided with a first and a second means of disconnection (20A, 20B), the display means (30) being functionally connected to the first and second disconnection means (20A, 20B) so as to provide a differentiated indication of the state of each of the protection components (10) taken individually. - Device according to claim 6 characterized in that the control piece (40) is mounted resiliently movable between an initial position, corresponding to a connected state of the two protective components (10), in which said control piece (40) is held in position by the two disconnection means (20A, 20B), an intermediate position, offset from the initial position, corresponding to a state where only one of the disconnection means (20A, 20B) is disconnected, in which the part control (40) is held in position by the disconnection means (20A, 20B) in the closed position, and a final position, offset from the intermediate position, corresponding to a state disconnected from the two disconnection means (20A, 20B). - Device according to claim 7 characterized in that the control part (40) comprises two stages of support zones (42, 43), arranged one behind the other in the direction of movement (F) of the part control (40), so as to ensure the locking of the control piece (40) successively in the two initial and intermediate positions. - Device according to claim 8 characterized in that the control part comprises a pair of so-called downstream support zones (42A, 42B), intended to come into abutment, in the initial position, against the two disconnection means (20A, 20B), and a pair of so-called upstream support zones (43A, 43B), arranged upstream of the first pair opposite of the direction of movement of the control part, so that in the intermediate position, one of the upstream support zones (43A, 43B) abuts against the corresponding disconnection means (20A, 20B) which remains in position closing. -A device according to claim 9 characterized in that the upstream support zones (43A, 43B) are formed by fingers (44) projecting on either side of the control part (40) and extending along a direction substantially perpendicular to the main direction of movement of the control piece (40). -A device according to claim 9 or 10 characterized in that it comprises means for guiding the movement of the control part (40), adapted to allow sufficient angular movement of the latter to allow, during the opening of the one of the disconnection means (20A, 20B), the crossing of the other disconnection means by one of the corresponding downstream support zones (42A, 42B). -A device according to claim 11 characterized in that the control part (40) is provided with release means (45), arranged to facilitate, during the passage of the control part (40) from the initial position to the intermediate position , the crossing of the disconnection means (20A, 20B) remained in the closed position. -A device according to claim 12 characterized in that the release means (45) are formed by oblique cutouts, formed on either side of the control part (40) at the end of the latter, and forming the downstream support zones (42A, 42B). -A device according to one of claims 6 to 13 characterized in that it comprises guide means (80) adapted to ensure the movement of the control piece (40) along a predetermined path formed by the combination of a movement of rotation and a translational movement. -A device according to claim 14 characterized in that the guide means (80) are formed by a lug (81), disposed on the control part (40), and a corresponding groove (82) in the form of a V, within from which the lug (81) is capable of moving. -A device according to one of the preceding claims, characterized in that the indication means (50) is formed by at least one display member, preferably a display panel (51), associated with the control part so as to move opposite a window (61) formed in the housing (60) of the device to obtain a different visual appearance through the window (61), depending on the position of the control part (40). -Device according to one of claims 1 to 6 characterized in that the indication means (50) is formed by a remote indicator, functionally connected to the control part (40) by means of a signaling system to distance. -A device according to claim 17 characterized in that the control part (40) is sufficiently flexible to allow angular movement of its front part (40A). -A device according to claim 18 characterized in that the control part (40) comprises a narrowing of section, giving it its flexible character. -A device according to one of claims 17 to 19 characterized in that the front part (40A) of the control piece (40) is in the form of a sphere intended to come into abutment against a fold (20C) formed in the disconnection means (20A, 20B), said fold (20C) being designed to form a stop against the control part (40). -Device according to one of the preceding claims, characterized in that the protective component (10) is formed by a varistor. -Device according to one of the preceding claims, characterized in that each disconnection means (20A, 20B) is formed by a disconnection blade (21), welded to one of the poles of the corresponding protection component (10), and able to move, under the action of an elastic restoring force, from the closed position to the open position after fusion of the weld, thereby releasing the control part (40). -Device according to one of the preceding claims, characterized in that it comprises a first control part (403), associated with a direct display member, as well as a second control part (404), associated with a descriptive indicator remote, the first and second control part (403, 404) being adapted to cooperate, independently of one another, with the disconnection means (20, 20A, 20B).