EP0209433A1 - Mobile contacts support, in particular for a protection circuit breaker - Google Patents

Abstract

The support piece according to the invention has a one-piece structure comprising a rigid sole (11) carrying the movable contacts (CM1, CM2), and an elastic blade (13) facing the sole, at a distance therefrom, and constituting a contact pressure spring. The invention applies in particular to protective switch devices of the circuit breaker type.

Description

The present invention relates to a support piece for one or more movable contacts, in particular for a circuit breaker-type protective switch device comprising in an insulating housing an interruptible current path on which is disposed at least one pair of cooperating contacts, the l one is fixed and the other of which is movable in response to actuation either of an electromagnetic or thermal tripping member, or of a voluntary tripping member, via a lock.

As is known from French patent application No. 84 19043 filed on December 13, 1984 in the name of the Applicant, for: "Protection switch device", the movable contact of the circuit breaker is disposed at a first end of a contact carrier rocker arm, of electrically conductive material, the second end of which is associated with an erasable support constituting the lock release member; moreover, the contact-carrying arm is subjected to the action of an elastic means, such as a hairpin torsion spring, used for opening and closing the movable contact.

In this mechanism, the two particular functions mentioned above, respectively for supporting the mobile contact and opening / closing of said movable contact, are respectively filled by two separate mechanical parts, namely the rocking arm, on the one hand, and the hairpin spring, on the other hand. However, the fact of using two separate parts which are dependent on each other, that is to say acting one on the other, to fulfill these two functions, has the drawback of complicating their relative arrangement in view of switching on and off of the circuit breaker.

On the other hand, as the rocker arm of this mechanism is associated, on the side of its end opposite to that carrying the movable contact, with the lock of the circuit breaker itself associated with the electromagnetic and / or thermal trip device, the established current path between the terminals of the circuit breaker therefore passes through the entire length of the contact-carrying arm, which is a drawback in that the arm risks being subjected to changes of state, in particular by heating and oxidation, which can lead to poor operation of the circuit breaker latching and tripping mechanism; to remedy this drawback, problems arise, generally delicate, of choice of material for the contact carrier rocker arm.

The object of the present invention is to remedy these drawbacks by proposing one and the same part, used in the latching and tripping mechanism of a circuit breaker in particular, which fulfills both the function of contact support (s). mobile (s) as well as the closing function of this (s) mobile contact (s), while also authorizing the opening of the latter (s). These two particular functions, which are in fact linked to each other, are therefore now grouped together on a single mechanical part, hence a certain simplification in the production of the circuit breaker mechanism.

To this end, the inventive idea of the so-called contact support part, object of the invention, resides in the fact that the said part has a one-piece structure comprising a rigid part carrying the movable contact (s) and an elastic part of the leaf-spring type used for closing this movable contact (s), and ensuring a so-called suitable contact pressure.

In its mounting in a circuit breaker, the support part according to the invention also has the advantage of not being part of the path taken by the electric current established between the terminals of the circuit breaker, thus simplifying the choice of the material of said part. .

The subject of the invention is therefore a support piece of at least one movable contact intended to cooperate with an associated fixed contact, in particular for a protective switch device of the circuit breaker type, the or each movable contact being capable of occupying either a position closing in which it is applied to its associated fixed contact, that is an open position in which it is separated from its associated fixed contact, said part consisting of a rigid sole bearing at one end the or each movable contact, characterized in that said piece also consists of an elastic blade facing the rigid sole, at a distance therefrom, situated in a plane substantially parallel to that of the sole, and connected to the latter by its end on the same side as the second end of the sole, by a connecting part made in one piece with the sole and the blade, the elastic blade constituting a spring ensuring the closing of or each contact t mobile under the effect of a force exerted on the blade, and authorizing the opening of or each mobile contact after the force is released.

• La figure 1 représente, en perspective, la pièce de support de deux contacts mobiles conformes à l'invention ;
• La figure 2 représente une vue selon la ligne II-II de la figure 1, avec illustration des deux positions que peut prendre la lame élastique ;
• La figure 3 représente schématiquement, en élévation, les principaux constituants d'un disjoncteur en position enclenchée et dont le mécanisme de commande des contacts comporte la pièce de support conforme à l'invention ;
• La figure 4 représente une vue de dessus de ce mécanisme de commande des contacts ;
• La figure 5 représente le schéma électrique du disjoncteur de la figure 3 montrant le chemin du courant électrique établi entre les bornes du disjoncteur ;
• Les figures 6 et 7 représentent, en élévation, une partie du disjoncteur de la figure 3, respectivement en une position intermédiaire de déclenchement et en sa position finale déclenchée ; et
• La figure 8 représente un détail du boîtier du disjoncteur.

Other characteristics and advantages of the invention will appear more clearly in the detailed description which follows and refers to the appended drawings given solely by way of example and in which:

• Figure 1 shows, in perspective, the support part of two movable contacts according to the invention;
• 2 shows a view along line II-II of Figure 1, with illustration of the two positions that can take the elastic blade;
• FIG. 3 schematically represents, in elevation, the main components of a circuit breaker in the engaged position and the contact control mechanism of which comprises the support part according to the invention;
• Figure 4 shows a top view of this contact control mechanism;
• FIG. 5 represents the electric diagram of the circuit breaker of FIG. 3 showing the path of the electric current established between the terminals of the circuit breaker;
• Figures 6 and 7 show, in elevation, part of the circuit breaker of Figure 3, respectively in an intermediate tripping position and in its final tripped position; and
• Figure 8 shows a detail of the circuit breaker housing.

In Figure 1, there is shown at 10 a support piece of two movable contacts CM ₁ and CM ₂ , according to the invention, and intended to be used in a control mechanism, in particular of a switch protection device of the breaker type.

As is known, the control mechanism of a circuit breaker aims, on the one hand, to ensure the closing of the electrical contacts by applying the or each movable contact to an associated fixed contact and, on the other hand, to cause these contacts to open by separating the or each movable contact from its associated fixed contact either following an electrical fault , short circuit or electrical overload, either by voluntary tripping.

It will also be indicated that there is shown by way of illustration only and without limitation, FIG. 1, two mobile contacts supported by the contact-holding part. of course, the latter can perfectly support only one mobile contact, without departing from the scope of the invention.

If we exclude the two contacts illustrated in FIG. 1, the support piece proper, for example made of steel, is profiled in one piece in several parts of particular shapes obtained by conventional mechanical operations such as cutting, rolling and folding.

Thus, the part 10 consists first of all of a rigid flat sole 11 of general shape defined by a rectangle, two of the corners of which are symmetrical with respect to the longitudinal axis of the rectangle, have each been eliminated by a short cut parallel to this axis, followed by a long oblique cut.

The sole 11 is extended, on its smallest lateral edge 11 a, by a part 12 rolled into a cylinder portion, of axis A ₁ perpendicular to the longitudinal direction of the sole. This cylindrical part 12 serves as a connection between the sole 11 and a flexible elastic blade 13 acting as a contact pressure spring and coming opposite the sole, at a distance from the latter.

The leaf spring 13, Figure 1, is rectangular, substantially the same length as the sole, and has a portion 13a tangentially connected to the cylin drique 12, in a central location thereof. The blade 13 is, on the other hand, slightly folded at 14 so that its portion 13b, in the absence of elastic deformation, is arranged parallel to the sole 11, at the level of the central part thereof.

From the middle of its lateral edge llb parallel and opposite to that contiguous to the cylindrical part 12, the sole 11 is extended by a rigid rectangular central tongue, generally identified at 16, of width slightly greater than that A of the leaf spring 13 , and profiled so as to present the following three successive branches: a first branch 16a folded perpendicularly to the longitudinal direction of the sole 11 and facing the free end of the spring leaf 13, at a short distance d from the latter ( Figure 2); a second branch 16b folded parallel to the longitudinal direction of said sole and overlapping the leaf spring 13, at a distance from the latter in its rest position illustrated in solid lines in FIG. 2; and a third branch 16c curved in the direction of the leaf spring so that its end comes to bear in P (FIG. 2) on the upper face of the leaf spring 13, transversely with respect thereto, when said leaf is at 'state of rest.

It will be observed that the leaf spring 13 being in the rest position, the part of its branch 13b which is under the roof formed by the folded parts of the tongue 16, defines, with the latter, a space 18 (FIG. 2) in which is likely to evolve a mechanical part, as we will see below.

As it appears in FIGS. 1 and 2, the support piece 10 also includes a continuous stiffening molding 20 serving to increase the inertia of said piece and extending longitudinally over the middle of the respective external faces of the different rigid parts. only, of the part, namely the sole 11 and the three branches 16a, 16b and 16c forming the tongue 16.

The two movable contacts CM ₁ and CM ₂ , FIG. 1, are formed in an identical manner respectively at one of the ends of two parallel arms 22 and 23 slightly bent and arranged projecting in the longitudinal direction of the sole 11 on either side and d 'other of the central tongue 16; these two arms are connected transversely to each other by a plate 25 which is fixed by any suitable means, such as for example by two rivets 27, for example on the upper surface of the sole 11, on the edge thereof. this. It will be noted that the two contacts CM ₁ and CM ₂ , as well as the two arms 22 and 23, and the plate 25, are made of an electrically conductive material, for example copper, and constitute, preferably, a single and even room.

From the above description, it can be concluded that the support part according to the invention has the following main characteristic: said part consists, on the one hand, of a rigid part 11 carrying the contact (s) ) movable (s) and, on the other hand, an elastic part 13 forming a contact pressure spring.

In more detail, with regard to the leaf spring 13, it is possible to exert on it a predetermined force f, (FIG. 2) which tends to cause it to flex, as illustrated in dotted lines in FIG. 2, over a height h defined by relative to its rest position at the support point P; in its working position, said blade therefore applies a certain closing pressure of the movable contacts on their associated fixed contacts.

FIG. 3 shows in elevation a protective switch device, the contact control mechanism of which comprises the support part according to the invention and as described above with reference to FIGS. 1 and 2.

This device is a modular circuit breaker with insulating housing 40, having two pairs of separable contacts, of which only the pair formed by the movable contact CM _I and its associated fixed contact CF ₁ is visible in FIG. 3, arranged on a planned current path in the housing between a first terminal 41 and a second terminal 42.

The housing 40 comprises an electromagnetic tripping member generally identified at 44, and a bimetal thermal tripping member 45, capable of actuating a lock 47 in order to separate the two movable contacts from their two associated fixed contacts, following a fault d electrical origin, short circuit or electrical overload, appearing at terminals 41 and 42.

We will now describe the structure of the lock 47 of the circuit breaker which implements the support part 10 according to the invention, with reference to FIGS. 3 and 4.

In addition to the contact-carrying part 10 already described and mounted in the housing on the fixed axis A ₁ , the lock 47 also includes a lever-shaped part 49 in the form of a cradle, of axis XX ′, having two parallel longitudinal arms 49a and 49b (Figure 4) connected transversely to each other, on the one hand, at a first end, by a pin 50 of axis A ₂ and, on the other hand, at a second end, opposite to the first , by a so-called trigger part 52 having a shoulder 52a (Figure 3).

When the circuit breaker is in the on position, as illustrated in FIG. 3, the journal 50 of the lever 49 bears on the leaf spring 13 of the contact-carrying part 10, transversely with respect to said blade, and exerts force on the latter. descending f _I which tends to make it bend as we have seen in connection with FIG. 2, while one end of a lever 54 bears against the shoulder 52a of the triggering part 52.

This lever 54, Figure 3, is carried by a support 55 cooperating with a rotary wheel 57 accessible from the outside of the housing and carrying graduations corresponding to various direct or relative values of the thermal trip current, via a finger 58 engaged in a groove 59 hollowed out in the wheel.

As seen in Figure 4, the lever 49 is subject to a double pin spring 61 mounted on the fixed axis A ₁ and whose two free ends 6la and 61b respectively come into abutment on the underside of two coaxial cylindrical tabs 63 and 64 respectively mounted perpendicularly on the two arms 49a and 49b of the lever; these spring ends are capable of exerting on each of the cleats of the lever 49 an ascending force f ₂ illustrated in FIG. 3. In addition, the pin spring 61 has a branch 61c folded transversely with respect to the axis XX '(FIG. 4 ) and coming to rest on a stop 66 (FIG. 3) provided in the housing 40.

In FIG. 3, a so-called voluntary tripping member such as, for example, a pivoting lever 68, of fixed axis A _{3 ′} is associated with the front face of the case 40 of the circuit breaker, and is conventionally biased by a spring not shown which tends to rotate it according to the arrow f ₃ about its axis A ₃ .

The lever 68 is, on the other hand, connected to the lever 49 by a toggle link 70 coming to rest, in the engaged position (Figure 3), on a stop 71 provided in the housing 40, and ending in two ranges 70a and 70b made integral respectively with the two arms 49a and 49b of the lever 49 (FIG. 4), and capable of moving each in a guide slot made in the housing 4D.

As seen in Figure 3, the electromagnetic trip member 44 of the circuit breaker is conventionally composed of a coil 75 inside which is susceptiblei ble of axially sliding a core 76. The latter is, on the other hand, articulated at 77 to a lever 78 mounted, at one of its ends, on a fixed axis A ₄ , and the other end of which is arranged in support on a hoop part 80 also forming a lever. This part 80 is itself mounted at one of its ends, on a fixed axis A ₅ , and its free end is arranged, via a ramp, opposite a stop lug disposed on the same end of the lever as that coming to bear against the triggering part 52.

E is shown in Figure 3, a rotary insulating screen, known per se, intended to be interposed between the contacts once opened during a tripping process.

In this same Figure 3, there is illustrated at 85a - 85d the various conductors used for the passage of electric current between the two terminals 41 and 42 of the circuit breaker housing in the engaged position.

In more detail, referring to FIG. 5, the current path I established between the terminals 41 and 42 when the circuit breaker is tripped, comprises the conductor 85a, the bimetallic strip 45, the flexible conductor 85b, the winding of the coil 75 of the electromagnetic trip device, the conductor 85c, the two pairs of contacts (CFl - CM ₁ , CF2 - CM2) with the link between the two movable contacts which is provided by the two arms 22 and 23 and the plate 25 (Figure 1) , and the conductor 85d.

Note that in the case of a single pair of contacts, the movable contact is then connected to the terminal 42 of the housing via a flexible conductor.

In view of this current path, it is important to note that the electric current absolutely does not flow in the contact control mechanism, constituted by the lock of the circuit breaker, and therefore in particular in the support piece proper according to the invention, which is particularly advantageous for the proper functioning of this mechanism.

The circuit breaker shown in Figure 3 operates as follows.

In the engaged position, Figure 3, the lever 68 occupies the position on the left in this figure, and the two movable contacts are applied to the two fixed contacts associated under the effect of the force produced by the pin 50, according to the arrow f _l , on the leaf spring 13 of the contact-carrying part 10. In addition, one of the ends of the lever 54 bears on the shoulder 52a of the triggering part 52 under the action of a non-spring indicated, while the other end of said lever is disposed relative to the bimetallic strip 45 at a given distance D which is defined, as is known, as a function of the chosen value of the thermal trip current.

For the tripping of the circuit breaker causing the opening of the contacts, we will simply explain it in the case of the appearance first of an electrical overload, then of a short circuit, it being understood that the tripping of the circuit breaker can also be voluntary, manual or automatic.

When an electrical overload appears, the bimetallic strip 45 undergoes a deflection of amplitude D towards the lever 54 and forces the latter to pivot clockwise to release it from the shoulder 52a of the triggering part 52. Once the lever 54 released from the part 52, and under the effect of the combined forces f ₂ and the reaction to f _l , the lever 49 pivots clockwise around the bearings 70a and 70b of the toggle mechanism 70.

This same pivoting of the lever 49 is also obtained in the event of the appearance of a short circuit, in the following manner.

The core 76 of the coil of the electromagnetic trip device undergoes a rectilinear displacement according to the arrow f ₅ of FIG. 3 and constrains the lever 78 to pivot in an anti-direction schedule. The latter then requests the part 80, the free end of which moves upwards and comes into abutment on the lug mounted at the end of the lever 54 to drive the latter out of the shoulder 52a of the triggering part 52. Consequently , as before, the lever 49 pivots clockwise around the spans of the toggle mechanism 70.

From this pivoting of the lever 49, a description will now be given of the circuit breaker tripping process which is just as valid in the event of an electrical overload as in the event of a short circuit, with reference to FIGS. 6 and 7.

Therefore, during the pivoting of the lever 49 clockwise, the pin 50 thereof pivots in the same direction, which has the effect of relaxing the leaf spring 13 which abuts in P on the branch 16c to occupy its rest position, as it appears in FIG. 6 which represents an intermediate tripping position of the circuit breaker. At this time, the reaction to f _I (FIG. 3) of the leaf spring 13 is canceled, and only the force f ₂ contributes to the pivoting of the lever 49; the pin 50 is therefore no longer supported on the leaf spring 13.

Consequently, by continuing to pivot in the space 18 defined as we have seen with regard to FIG. 2, the pin 50 abuts on the branch 16c of the contact-carrying part 10, as illustrated in FIG. 6 , and then causes the contact-piece 10 to tilt in a clockwise direction around its axis A ₁ . which has the effect of separating the two movable contacts from their two associated fixed contacts (FIG. 6).

Thus, it can be said that the leaf spring of the contact-carrying part according to the invention allows the opening of the movable contacts after the force produced by the journal of the lever on the said leaf spring has been released.

It will be observed that during the pivoting of the lever 49, each of the bearing surfaces of the toggle joint 70 moves in a guide slot made in the housing 40 of the circuit breaker.

FIG. 8 represents this slot 90, of generally oblong shape, in which the range 70a for example moves to pass from a low position 70al when the circuit breaker is tripped, to a high position 70a ₂ during tripping of the circuit breaker.

Thus, after passing the neutral point of the toggle joint 70, and under the effect of its own assistance spring, the lever 68 passes from the position of FIG. 6 to that of FIG. 7 which illustrates the final triggering position of the circuit breaker; the toggle joint 70 therefore causes the lever 49 to be lifted, the pin 50 of which, when the contacts open, slides over the folded bottom of the branch 16b of the contact-carrying part 10, as it appears in FIG. 7.

After tripping on fault, resetting is automatic; the elements of the circuit breaker occupying the position indicated in FIG. 7, the lever is brought to the left, causing a lowering and pivoting of the lever 49 counterclockwise; consequently, the lever 54 comes back to its position in abutment against the shoulder of the triggering part 52, while the journal 50 exerts on the leaf spring 13 a determined downward force f _{1 in} order to apply, with the desired pressure, the two movable contacts on their two associated fixed contacts.

Of course, the invention is in no way limited to the embodiment described and shown and includes all the technical equivalents of the means described, as well as their combinations if these are carried out according to the spirit of the invention and implemented in the context of the claims which follow.

Claims (7)

1. Support piece of at least one movable contact intended to cooperate with an associated fixed contact, in particular for a protective switch device of the circuit breaker type, the or each movable contact (CM ₁ , CM ₂ ) being capable of occupying either a closed position in which it is applied to its associated fixed contact, or an open position in which it is separated from its associated fixed contact, said part consisting of a rigid sole (11) carrying at one end the or each movable contact (CM ,, ^CM ₂ ), characterized in that said part also consists of an elastic blade (13) facing the rigid sole (11), at a distance from the latter, situated in a plane substantially parallel to that of the sole, and connected thereto, by its end on the same side as the second end of the sole, by a connecting part (12) made in one piece with the sole (11) and the blade (13), the elastic blade constituting a spring ensuring the closure ture of the or each movable contact under the effect of a force exerted on the blade, and authorizing the opening of the or each movable contact after the effort is released. , 2. Support piece according to claim 1, characterized in that the sole (11) is extended, at its first end, by a rigid central tongue (16) ending in a branch (16c) bent in the direction of the elastic blade (13 ), on the side thereof opposite to that facing the sole, and oriented substantially transversely with respect to the blade, so that said blade abuts against this branch for the opening of or each movable contact. 3. Support piece according to claim 2, characterized in that the tongue (16) has a rectangular shape, is made in one piece with the sole, and is profiled so as to present successively, from of the sole, a first branch (16a) substantially perpendicular to the sole and facing the blade (13), a second branch (16b) substantially parallel to the sole and overlapping the blade (13), at a distance from the latter , and a third inclined branch (16c) constituting said branch against which the blade is capable of abutting. 4. Support piece according to one of claims 2 or 3,
characterized in that it comprises a stiffening molding (20) extending longitudinally on the respective external faces of the sole (11) and the tongue (16), substantially in the middle of these. 5. Support piece according to one of the preceding claims,
characterized in that the part (12) connecting between the blade (13) and the sole (11) is constituted by a portion of cylinder oriented transversely with respect to the sole (11). 6. Support piece according to one of claims 2 to 5, comprising two movable contacts (CM ₁ , CM2) r
characterized in that the two movable contacts are respectively formed at the end of two parallel arms (22, 23), projecting in a longitudinal direction of the sole (11) on either side of the tongue (16), and transversely connected to each other by an electrically conductive plate (25) which is fixed on the sole. 7. Support piece according to claim 6, characterized in that the two contacts (CM ₁ , CM ₂ ), the two arms (22, 23), as well as the plate (25), constitute a single piece of material conductor of electricity.

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