EP1047090A1 - Limiting circuit breaker comprising an auxiliary energy accumulator - Google Patents

Abstract

Circuit breaker comprises housing, opening mechanism with energy accumulator, and poles. Each pole has auxiliary mechanism w energy accumulators drawing back support (58) towards opening position on all or part of support stroke, between closing positio and intermediate tipping over position, but more further than intermediate position.

Description

The invention relates to a low voltage limiting circuit breaker, and more particularly to a high caliber low voltage circuit breaker.

• un boítier ;
• un mécanisme d'ouverture comportant au moins un accumulateur d'énergie ;
• un ou plusieurs pôles comportant chacun :
  • un organe de contact fixe par rapport au boítier ;
  • une butée fixe par rapport au boítier ;
  • un organe de contact mobile comportant :
    • un support mobile relativement au boítier entre une position de fermeture et une position d'ouverture ;
    • au moins un doigt de contact mobile relativement au support entre une position non répulsée et une position répulsée ;
    • au moins un mécanisme bistable comportant un ressort disposé entre le support et le doigt de telle manière qu'il passe par un maximum d'énergie potentielle lorsque le doigt et le support sont situés dans une position de point mort relativement l'un à l'autre, qu'il tende à rappeler le doigt vers sa position répulsée lorsque le doigt est situé relativement au support entre sa position répulsée et la position de point mort, et qu'il tende à rappeler le doigt vers sa position non répulsée lorsque le doigt est situé relativement au support entre sa position non répulsée et la position de point mort ;
  la butée étant disposée de telle manière que lorsque le doigt est positionné dans sa position répulsée et que le support passe de sa position de fermeture à sa position d'ouverture, le doigt, une fois en contact avec la butée, reste en contact avec celle-ci jusqu'à ce que le support dépasse une position intermédiaire de basculement relativement au boítier, correspondant à la position relative de point mort par rapport au doigt,

le mécanisme d'ouverture étant lié cinématiquement au support de manière à rappeler le support vers sa position d'ouverture lorsque le support se trouve dans sa position de fermeture. Document GB-A-1 564 412 describes a high-caliber low-voltage limiting circuit breaker, comprising

• a housing ;
• an opening mechanism comprising at least one energy accumulator;
• one or more poles each comprising:
  • a contact member fixed relative to the housing;
  • a fixed stop relative to the housing;
  • a movable contact member comprising:
    • a movable support relative to the housing between a closed position and an open position;
    • at least one movable contact finger relative to the support between a non-repulsed position and a repulsed position;
    • at least one bistable mechanism comprising a spring disposed between the support and the finger so that it passes through a maximum of potential energy when the finger and the support are located in a neutral position relatively to each other other, that it tends to recall the finger to its repulsed position when the finger is located relative to the support between its repulsed position and the neutral position, and that it tends to recall the finger to its non-repulsed position when the finger is located relative to the support between its non-repulsed position and the neutral position;
  the stop being arranged in such a way that when the finger is positioned in its repulsed position and the support passes from its closed position to its open position, the finger, once in contact with the stop, remains in contact with that -this until the support exceeds an intermediate tilting position relative to the housing, corresponding to the relative neutral position relative to the finger,

the opening mechanism being kinematically linked to the support so as to return the support to its open position when the support is in its closed position.

The spring of the bistable device combines several functions. It is intended first of all to ensure contact pressure between the fixed contact member and the contact finger when the circuit breaker is closed, which is relatively independent of the state of wear and circuit breaker manufacturing tolerances. This contact pressure is otherwise determining for the repulsion threshold beyond which the electromagnetic forces will lead the finger to its repulsed position. When the finger has rotated beyond the neutral, the spring also serves to confirm repulsion and / or to prevent a rebound of the finger, since it prohibits the return of the finger to the non-repulsed position. Before to be able to close the circuit breaker again, so it is necessary to release the energy accumulator of the opening mechanism, which drives the bar and with it the support of the movable contact member in the open position, and which allows the finger to pivot in the non-repulsed position by cooperation with the stop.

In such a device, the energy accumulator of the opening mechanism must overcome the resistance of the spring of the bistable device. However, this passage should preferably be made at the start of the opening stroke, in order to limit the size of the compartment of the circuit breaker where the contacts are located. The support must rotate quickly enough, on passing from the intermediate tilting position, so that the return force of the spring of the bistable device does not give rise, after the transition from neutral to a significant approximation between the finger and the fixed contact.

Consequently, the spring of the opening mechanism must simultaneously accelerate the support and compress the spring of the bistable device. In energy terms, it must simultaneously supply the spring of the bistable device with the energy necessary for it reaches its maximum potential energy state, and provide support the kinetic energy necessary for its rapid displacement towards the open position. Also remember that the spring of the opening mechanism must also ensure only the rapid opening of the circuit breaker in the event of tripping on low overcurrent.

To reconcile these constraints, an energy accumulator is generally provided powerful opening. However, this solution is not without drawbacks, since the energy released during the opening must be dissipated in the end stops opening, so the power of the spring is decisive for the cost and the size of the circuit breaker. In addition, it is necessary to provide mechanisms different opening depending on the number of poles of the circuit breaker. Remember that not only meets monopolar, three-pole and four-pole circuit breakers, but also, for high ratings where each phase is connected to two poles in parallel or in series, hexapolar or even octopolar circuit breakers.

The dimensioning problem is even more complicated when identical movable contacts, using supports, fingers and bistable devices identical, are intended to equip circuit breakers whose opening mechanisms are different in nature. We want to be able to equip a range of circuit breakers indifferently with a first type of mechanism in which the energy accumulator in the opening mechanism also releases energy necessary to close the circuit breaker, and with a second type of mechanism, said O-F-O (for open, closed, open) in which an energy accumulator of closing is armed regardless of the position of the contacts and ensures arming of the opening energy accumulator simultaneously during closing. Now the two types of mechanism have different opening kinematics. We consider as well as generally that, for a given opening energy - that is to say for a given opening spring - the O-F-O mechanism is slower at the start of the stroke and faster at the end of the opening stroke.

The invention therefore aims to remedy the drawbacks of the state of the art, and in particular to allow the use of movable contact members with mechanisms identical bistables for limiting circuit breakers including opening mechanisms have variable characteristics, especially at the start of the opening stroke. She aims also to allow a dimensioning of the opening mechanism of a limiting circuit breaker, independent of the number of poles. Another objective of the invention is to make the acceleration at the start of the opening stroke of the support of an organ mobile contact relatively independent of the type of opening mechanism used artwork. Another objective of the invention is to limit the energy to be dissipated at the end of opening stroke, without significantly increasing either the opening stroke or the size of the device. Another objective is to minimize the energy required when opening.

According to the invention, these objectives are achieved by means of a circuit breaker of the previous type, in which each pole further comprises an auxiliary mechanism comprising one or more several energy accumulators recalling the support to its open position on all or part of the travel of the support between its closed position and the position intermediate tilting, but no longer beyond the intermediate position of tilting. It is then possible to adjust the acceleration at the start of the race opening by judiciously choosing the power of the second accumulator.

Preferably, the energy accumulator (s) of the auxiliary mechanism do not act on the support when it is between its intermediate position tilt and its open position. Beyond the tilting position, the support does not need a lot of energy to reach its open position, so that the contribution of the second accumulator is no longer necessary.

Alternatively, it is possible to provide an accumulator supplying energy to the support for at least part of its travel between the closed position and the intermediate tilting position, and storing energy on a part at less of the travel of the support between the intermediate position and the position opening hours. This accumulator can for example comprise a spring whose position of rest corresponds to the relative tilting position, acting in compression in below and in traction beyond. This further limits the energy remaining to dissipate in the end of travel stops the opening mechanism at the end of travel opening hours.

Preferably, the energy accumulator (s) of the auxiliary mechanism of each pole are such that when moving the mobile support of the pole in question, they release an energy greater than or equal to that necessary to bring the bistable mechanisms of the pole considered up to their maximum potential energy. This arrangement is particularly advantageous for a multipole circuit breaker comprising a control mechanism common to all the poles. Indeed, it is then even easier to size the opening spring independently of the number of poles, while limiting its power.

According to one embodiment, the circuit breaker further comprises means hanging. This arrangement favors the passage from the intermediate position of tilting to the open position. It therefore makes it possible to limit the kinetic energy necessary for passage from the intermediate tilting position. this allows therefore limit the power of the auxiliary mechanism and further limit the energy to be dissipated in the opening end-of-travel stops.

According to a preferred embodiment, the energy accumulator (s) of the mechanism auxiliary each comprise a spring disposed between the housing and the support. Alternatively, it would naturally be possible to activate the accumulators auxiliaries indirectly on the support, for example on an intermediate part of the kinematic chain of transmission linking the energy accumulator of the mechanism opening to the support. However, the preferred embodiment offers the advantage of limit the constraints on this kinematic chain. Advantageously, the housing includes polar compartments each containing one of said poles, the spring of each energy accumulator of the auxiliary mechanism of each pole being arranged in the corresponding polar compartment.

According to one embodiment, the spring is a compression spring arranged at the interior of a cylinder closed by a piston head capable of coming into contact with the support and transmit the force of the compression spring to it. Alternately, other types of springs can be envisaged, for example torsion springs or bending.

• la figure 1 représente une vue en coupe d'un disjoncteur selon l'invention, en position fermée non répulsée ;
• la figure 2 représente en coupe le disjoncteur de la figure 1, en position fermée, partiellement répulsée, au passage d'un point mort ;
• la figure 3 représente en coupe le disjoncteur de la figure 1, en position fermée, répulsée ;
• la figure 4 représente en coupe le disjoncteur de la figure 1, dans une position intermédiaire de basculement ;
• la figure 5 représente en coupe le disjoncteur de la figure 1, en position ouverte ;
• la figure 6 représente dans un plan de coupe parallèle à celui de la figure 1, un mécanisme d'accrochage dans une position correspondant à la position fermée répulsée de la figure 3.

Other advantages and characteristics of the invention will emerge from the description which follows of an embodiment of the invention, given by way of nonlimiting example and represented in the appended drawings in which:

• Figure 1 shows a sectional view of a circuit breaker according to the invention, in the closed position not repulsed;
• 2 shows in section the circuit breaker of Figure 1, in the closed position, partially repulsed, when passing through a neutral position;
• Figure 3 shows in section the circuit breaker of Figure 1, in the closed, repulsed position;
• Figure 4 shows in section the circuit breaker of Figure 1, in an intermediate tilting position;
• Figure 5 shows in section the circuit breaker of Figure 1, in the open position;
• FIG. 6 represents in a section plane parallel to that of FIG. 1, a latching mechanism in a position corresponding to the closed repulsed position of FIG. 3.

With reference to FIGS. 1 to 5, a low-voltage limiter multi-pole circuit breaker high caliber 10 includes a housing 12 divided into a front compartment 14 and a rear compartment 16 by an intermediate wall 18. A window 20 made in the intermediate wall allows communication between the front compartments and later.

The front compartment 14 serves as a housing for a control device 22, which includes an energy storage closure mechanism 24 and a mechanism 26. This device is known per se and we will refer for more details to document FR-A-2 589 626. We will simply recall here that the mechanism opening 26 includes a toggle device which includes two links 28, 30 articulated to each other by a pivot axis 32, the lower link 30 of transmission being coupled to a crank 34 of a switching rod 36. An opening spring 38 is anchored between the crank 34 and a fixed cleat of deduction 40.

The rear compartment 16 serves as a housing for the switching rod 36 and for a plurality of poles 42 arranged side by side along a pivot axis 44 of the switching rod 36, in elementary compartments separated by watertight bulkheads substantially parallel to the plane of Figures 1 to 5. Each pole 42 comprises a fixed contact member 46 connected to a connection pad 48, a movable contact member 50 connected to a connection pad 52 and a chamber arc extinguishing device 54 fitted with metal separators 56. The contact member mobile 50 includes a mobile support 58 mounted to pivot about an axis geometric 60 fixed relative to the housing, and a contact finger 62 pivoting around of a geometric axis 64 fixed relative to the housing, and eccentric relative to the axis 60. A connecting rod 66 couples the support 58 to the switching bar 36. One end of the finger 62 supports a contact pad 68 intended to ensure the contact with a contact pad 70 supported by the fixed contact member 46. The other end of the finger 62 constitutes a cam 72 with two ramps 74, 76 on the one hand and on the other from a top dead center 78. Between the support 58 and the finger 62 is disposed elastic energy accumulator, comprising a spring 82 guided in a cage 84 and pushing out of it a rod 86 supporting a rotary roller 88. The roller 88 is thus permanently in contact with the cam 72. The elastic energy accumulator constitutes with the cam 72 a bistable mechanism 80.

Between the housing 12 and the support 58 is arranged an elastic energy accumulator auxiliary 90, visible in its relaxed state in FIG. 5, and comprising a spring 92 compression tending to push towards the support 58 a head 94 guided in translation in a cylinder 96 fixed relative to the housing 12. The front part of the head 94 comprises a bead 98 intended to cooperate radially with the cylinder to provide guidance, and axially with a flange 100 partially closing the cylinder and forming limit stop.

A hooking device 102, visible in detail in FIG. 6, comprises an arm 104 pivoting around a fixed axis 106 and resiliently recalled, clockwise on the figure, by a torsion spring 108. A movable stop 110 is located at the end of the arm 104 and cooperates with a stepped surface 112 of finger 62. The arm has in addition to a lug 114, capable of cooperating with a cam 116 located on the support 58.

The intermediate wall 18 supports an end of travel stop 118 made of material elastomer.

The operation of the device is as follows.

In the closed position of FIG. 1, the contact pads 68, 70 are in contact with each other and ensure the closure of the electrical circuit between the ranges of connection 48, 52. The spring 82 of the bistable mechanism 80 is compressed and the roller 88 cooperates with the ramp 74 so as to ensure contact pressure between the pads 68, 70. In the presence of an overcurrent, the electromagnetic forces tend to rotate finger 62 around its axis clockwise on the figures, and the bistable mechanism 80 tends to oppose this pivoting. When the current intensity exceeds a limitation threshold corresponding to the setting of the spring 82, the finger 62 pivots and passes the neutral point 78 of the bistable mechanism 80, represented in FIG. 2. Once this neutral point has passed, the roller 88 cooperates with the ramp 76 and contributes to pushing the finger 62 towards the end of travel stop 118, up to the position of FIG. 3. The stop 118 acts as a shock absorber and allows, by absorbing the excess kinetic energy, to avoid a rebound of the finger 62. The stop 110 of the hooking device 102 pivots under the stress of its spring 108 and remains in contact with the stepped surface 112 of the finger 62, so that the hooking mechanism 102 prohibits the return of the finger 62 to the low position.

To be able to close the circuit breaker, it is necessary beforehand to carry out a opening operation by the control mechanism. An opening lock, actuated by an operator or a trigger, releases the linkage 28, 30, 32. The opening spring 38, assisted by the springs 92 of the auxiliary accumulators 90 of each pole, causes the switching rod 36 to rotate in the opposite direction clockwise and, through the connecting rod 66, rotates the support 58 around its axis 60 clockwise from the position of Figure 3 to the position of Figure 4 then continues alone to urge the bar 36 until is reached the position of figure 5.

Between the position of Figure 3 and that of Figure 4, the roller 88 cooperates with the ramp 76 and apply a force on finger 62 whose moment tends to rotate the finger 62 clockwise around the axis 64. The damper 118 then plays the role an end of travel stop, so that the finger 62 remains stationary; So this is the roller 88 which disappears by compressing the spring 82. In this phase, the accumulator auxiliary energy 80 of each pole repels the corresponding support 58. The head 94 of the auxiliary accumulator 80 reaches its end position when the support 58 reaches the intermediate tilting position of FIG. 4, so that the contact between the head of the auxiliary accumulator and the support ceases.

Beyond this intermediate tilting position, the roller 88 urges the ramp 74. The movement of finger 62 anticlockwise is however counteracted by the stop 110 of the latch 102, so that the finger 62 remains relatively immobile, apart from the mounting clearance. Spring action opening 38 and that of the spring 82 of the bistable mechanism combine and drive the support 58 clockwise to its upper position in FIG. 5. In a intermediate position between the position of Figure 4 and that of Figure 5, very close to the latter, the cam 116 of the support 58 pushes back the lug 114 of the arm 104, so that the latter pivots anticlockwise and releases the stop 110. However, this release does not cause significant pivoting of the finger 62 counterclockwise because the movement of the support 58 is then practically completed.

From the position of Figure 6, the closure can be triggered by action on a closing latch which releases a closing spring, pivoting the bar switching from its position in FIG. 6 to its closed position in FIG. 1. The bar 36 drives the support 58 counterclockwise and the finger 62, urged only by the roller 88 which follows the movement of the support 58, is also trained. The support 58 compresses and recharges the spring 92 the auxiliary accumulator 90 at the end of the closing stroke. this allows incidentally to limit the impact at the end of the closing stroke.

By way of simplification, the invention has been described by considering that each pole comprises a single contact finger 62, a single bistable mechanism 80 and a auxiliary battery 90 single. In practice, it may be advantageous to plan a plurality of fingers per pole, for example three or five identical fingers pivoting around a common axis 64. Each finger must then be activated by a mechanism bistable, which can be common to several fingers or independent for each finger, so that each finger is stressed by a different spring. Support 58 remains unique to each pole. Depending on the size of the support 58, in particular its width in a direction perpendicular to the plane of the figures, it may be advantageous to provide an auxiliary accumulator 90 comprising several springs arranged in parallel. In practice, three springs arranged in parallel and each acting on a different head, allow to obtain interesting dimensional characteristics.

In practice, it is advantageous to size the auxiliary accumulators in such a way so that they release together when they relax an energy greater than that necessary to compress the spring of the bistable mechanism.

Naturally, the invention is not limited to the embodiment described above. Various modifications are possible within the scope of the invention.

In the previous example, the attachment mechanism 102 performs two functions: it on the one hand serves as an anti-rebound, in the sense that it avoids, in the event of a short circuit of very high intensity generating significant electrodynamic forces, that the finger, arrived in the position of FIG. 3 and coming to strike the shock absorber 118 violently, do not rebounds and does not come back to close the contact; moreover, it prevents the pivoting of the finger 62 during opening, when the support 58 has just exceeded the position intermediate tipping. However, depending on the rating of the circuit breaker and the dimensioning of mechanical parts, it can be envisaged to eliminate this hanging mechanism. The anti-rebound function is then assumed exclusively by the bistable mechanism 80, assisted if necessary by the end shock absorber stroke 118. As for the movement beyond the intermediate tilting position, it can be limited in size until it becomes imperceptible, if the speed of the support 58 when passing from the tilting position is sufficient.

In the embodiment described, the stop 118 performs two functions: on the one hand it acts as an anti-rebound since it absorbs part of the kinetic energy at the end of travel of the finger 62 towards its repulsed position; it also allows to immobilize the finger 62 when the support 58 pivots from its closed position to its intermediate tilting position. According to an alternative embodiment, these two functions can be performed by different bodies. An end stop repulsion stroke of the finger can for example be arranged on the support 58, and a independent stopper arranged on the housing. This arrangement allows lifting together the support 58 and the finger 62 repulsed in a first part of the travel of the support 58 to its open position, before finger 62 meets the stop of the housing and does not stop in relation to it.

The invention has been described with reference to a limiting circuit breaker whose fingers pivot around a geometrical axis 64 fixed relative to the housing. However, she is also applicable to a limiting circuit breaker as described for example in the document GB-A-1 564 412, the fingers of which pivot about an axis fixed relative to to the pivoting support itself around a fixed axis relative to the housing, and offset by compared to the previous one.

The switching bar 36 and the support 58 can constitute a single piece, in which case the connecting rod 66 disappears and the linkage 28, 30, 32 of the mechanism control is directly articulated by one of its ends on the support. This configuration corresponds to the mechanism of document GB-A-1 564 412.

The invention is applicable regardless of the type of opening mechanism and closing of the circuit breaker.

Claims (7)

Low-voltage limiter circuit breaker (10) comprising a housing (12); an opening mechanism (26) comprising at least one energy accumulator (38); one or more poles (42) each comprising: a fixed contact member (46) relative to the housing; a fixed stop (118) relative to the housing; a movable contact member (50) comprising: a support (58) movable relative to the housing between a closed position and an open position; at least one contact finger (62) movable between a non-repulsed position and a repulsed position relative to the support; at least one bistable mechanism (80) comprising a spring (82) disposed between the support and the finger so that it passes through a maximum of potential energy when the finger and the support are located in a relatively neutral position to each other, that it tends to recall the finger towards its repulsed position when the finger is located relative to the support between its repulsed position and the neutral position, and that it tends to recall the finger towards its non-repulsed position when the finger is located relative to the support between its non-repulsed position and the neutral position; the stop (118) being arranged in such a way that when the finger (62) is positioned in its repulsed position and the support (58) passes from its closed position to its open position, the finger (62), a once in contact with the stop (118), remains in contact with the latter until the support exceeds an intermediate tilting position relative to the housing, corresponding to the relative neutral position relative to the finger, the opening mechanism (26) being kinematically linked to the support (58) so as to return the support to its open position when the support is in its closed position;
characterized in that each pole (42) further comprises an auxiliary mechanism comprising one or more energy accumulators (90) returning the support (58) to its open position over all or part of the travel of the support between its position closing position and the intermediate tilting position, but no longer beyond the intermediate tilting position. Circuit breaker according to claim 1 characterized in that the accumulator (s) energy (90) of the auxiliary mechanism do not act on the support (58) when it is between its intermediate tilting position and its position opening hours. Circuit breaker according to claim 1 characterized in that the accumulator (s) energy (90) of the auxiliary mechanism of each pole (42) are such that during the displacement of the support (58) of the pole considered, they release a higher energy or equal to that necessary to bring the bistable mechanism (s) (80) from the pole considered up to their maximum potential energy. Circuit breaker according to claim 1 characterized in that it further comprises attachment means (102). Circuit breaker according to claim 1 characterized in that the accumulator (s) of the auxiliary mechanism (90) each have a spring (92) arranged between the housing (12) and the support (58). Circuit breaker according to claim 5, characterized in that the housing (12) comprises polar compartments each containing one of said poles (42), the spring (92) of each energy accumulator (90) of the auxiliary mechanism of each pole being arranged in the corresponding polar compartment. Circuit breaker according to claim 6, characterized in that the spring (92) of each energy accumulator (90) of the auxiliary mechanism is a compression spring disposed inside a cylinder (96) closed by a piston head (94) capable of come into contact with the support (58) and transmit to it the force of the spring compression.

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