EP2398034B1 - Auxiliary trip device for a breaker block - Google Patents

Description

The present invention relates to an auxiliary trip device housed in a modular insulating housing that can be attached to a circuit breaker block. The document EP-A-0 813 219 discloses such a tripping device comprising a control mechanism having a tripping link for acting on the tripping latch of the circuit breaker block, said mechanism comprising a transmission rod coupled to a handle, a plate rotatably mounted in the housing and having a mechanical link breakable with the transmission rod, and a trigger lever controlled by an electromagnet to cause in the event of a fault, the breakage of the mechanical link causing the automatic triggering of the mechanism independently of the handle and the actuation of the lock triggering the associated circuit breaker block, said mechanism being recalled in a position armed by the lever against a return spring said first able to drive the plate in the unlocked position of the breaker block in case of tripping, an electro magnet with an excitation coil and a magnet circuit mobile frame tick, which can occupy either a first position spaced from the magnetic circuit under the action of a so-called second return spring, or a second close position of the magnetic circuit by electromagnetic attraction during the excitation of the coil, said armature cooperating with the aforementioned trigger lever.

Auxiliary devices with no voltage are intended in a manner known per se to cause the opening of the circuit breaker when the grid voltage is too low compared to its nominal value, or if the voltage at its terminals is cut off by a stop emergency. An electromagnet is kept under tension. When the voltage drops below a predefined threshold, the electromagnet is deactivated and it activates the trigger bar of a mechanism previously armed by the joystick. The electromagnet is reactivated mechanically when the auxiliary mechanism is triggered before its coil is energized again. Bringing the gap of the magnetic circuit of the coil to zero allows to limit the current required for the gluing of the pallet and thus to limit the temperature rise.
The reactivation of the electromagnet usually performed by the main spring acting on the pallet by means of an arm provided for this purpose on the plate, consumes a portion of the energy supplied by the mechanism to achieve the opening of the contacts the associated breaker block. The adaptation of the power characteristic "race / force" of the auxiliary to that resistant circuit breaker is altered because the plate presses on the pallet to close it, which pallet opposes the force of its opening spring.

The present invention solves this problem and provides an auxiliary trigger device, simple design, to compensate for the alteration of this characteristic "force / stroke" of the mechanism without degrading the performance of the auxiliary.

For this purpose, the present invention relates to a device of the kind mentioned above, this device being characterized in that it comprises means for returning the armature in the second position after a trigger, these means comprising an arm supported by the platinum and a said third spring stretched by the arm of the plate in the armed position of the mechanism, said third said spring being adapted to exert a force on the arm of the plate during its expansion, after unlocking the plate, so as to recall the mobile armature formed by a pallet to the aforementioned second position close to the magnetic circuit.

According to another characteristic, the so-called third spring and the arm of the plate are shaped and arranged in such a way that, at the beginning of triggering, the direction of the initial force applied to the arm of the plate is such that the torque transmitted to the arm of the plate is weak, that during a movement of the arm following the expansion of the spring, the direction of the force of the spring on the arm changes so that the torque transmitted to the arm is amplified in an intermediate phase when the so-called first spring is no longer sufficient to simultaneously supply the minimum driving energy required for unlocking the trip latch of the circuit breaker block and the resetting of the magnetic circuit, and that at the end of tripping the torque transmitted to the arm is low.

According to another characteristic, the so-called third spring is a torsion spring.

According to another characteristic, said third spring has an end bearing on the housing and an end resting on the arm of the plate in an armed position of the mechanism, the two ends of the spring resting on the housing in the tripped position of the mechanism, the change of the fulcrum of the second end of the spring, a position resting on the arm to a position bearing on the housing having been driven by the displacement of the plate during a trigger or else a rest of the joystick.

According to another characteristic, it is a tripping device with no voltage.

• La figure 1 est une vue de face illustrant la partie intérieure d'un dispositif de déclenchement auxiliaire selon une réalisation particulière de l'invention, ledit dispositif étant dans une position fermée et armée, le circuit magnétique étant fermé,
• La figure 2 est une vue partielle, vue de l'arrière par rapport à la figure précédente, illustrant seulement le mécanisme du dispositif et le circuit magnétique dans la même position,
• La figure 3 est une vue identique à la figure 1, au début d'un déclenchement, le circuit magnétique étant en train de s'ouvrir,
• La figure 3a est une vue partielle de la figure 3, illustrant le déclenchement du mécanisme,
• La figure 4 est une vue identique à la figure 2, dans une position du dispositif correspondant à la figure 3,
• La figure 5 est une vue identique à la figure 1, après un déclenchement du dispositif dans une position de celui-ci plus avancée par rapport à la figure 3, la manette étant toujours fermée, mais le mécanisme étant en train de revenir en arrière,
• La figure 6 est une vue identique à la figure 2, dans une position du dispositif correspondant à la figure 5,
• La figure 7 est une vue identique à la figure 1, dans une position au repos du dispositif après un déclenchement, la manette étant ouverte,
• La figure 8 est une vue identique à la figure 2, dans la position du dispositif correspondant à la figure 7,
• La figure 9 est une vue identique à la figure 7, la platine ayant été retirée, et
• La figure 10 est une vue en perspective de la figure précédente.

But other advantages and features of the invention will become more apparent in the detailed description which follows and refers to the accompanying drawings given solely by way of example and in which:

• The figure 1 is a front view illustrating the inner portion of an auxiliary trigger device according to a particular embodiment of the invention, said device being in a closed and armed position, the magnetic circuit being closed,
• The figure 2 is a partial view, seen from the rear with respect to the preceding figure, illustrating only the mechanism of the device and the magnetic circuit in the same position,
• The figure 3 is a view identical to the figure 1 at the beginning of a trigger, the magnetic circuit being open,
• The figure 3a is a partial view of the figure 3 , illustrating the triggering of the mechanism,
• The figure 4 is a view identical to the figure 2 in a position of the device corresponding to the figure 3 ,
• The figure 5 is a view identical to the figure 1 , after a triggering of the device in a position of it more advanced compared to the figure 3 , the lever being always closed, but the mechanism being going back,
• The figure 6 is a view identical to the figure 2 in a position of the device corresponding to the figure 5 ,
• The figure 7 is a view identical to the figure 1 in a rest position of the device after a trigger, the handle being open,
• The figure 8 is a view identical to the figure 2 in the position of the device corresponding to the figure 7 ,
• The figure 9 is a view identical to the figure 7 the platen having been removed, and
• The figure 10 is a perspective view of the previous figure.

In the figures, there is shown an auxiliary triggering device D according to a particular embodiment of the invention, in particular an undervoltage release, housed in a modular insulating housing 1 which can be attached to a circuit breaker block (not shown), said triggering device mainly comprising a control mechanism 2 and an electromagnet 3. This control mechanism 2 has a tripping link intended to act on the tripping latch of the associated breaker block. This electromagnet 3 is provided with an excitation coil 4 and a magnetic circuit 5 with a movable armature 6, which can occupy either a first position spaced apart from the magnetic circuit, a position in which said armature is biased under the action a second said return spring 12, a second position close to said circuit by electromagnetic attraction against said spring, during the excitation of the coil. The electromagnet 3 comprises in known manner a magnetic circuit consisting of a magnetic "U" 5 made of ferromagnetic steel, cooperating with a movable armature formed by a pivoting pallet 6 and a coil 4 carried by an insulating carcass.

In a manner known per se, the control mechanism 2 comprises a trigger lever 7 pivotally mounted on a turntable 8. This plate 8 further comprises a hooking lever 9 cooperating on the one hand with the release lever 7 and on the other hand, with a transmission rod 10 coupled to a reset lever 11. The rod 10 acts on the plate 8 by means of the attachment lever 9, which is locked by the release lever 7. When a trigger, a torque is transmitted to the plate 8 by a so-called first spring 13 reset by the lever 11 after each trip. Thus, when the attachment between the link 10 and the plate 8 of the mechanism is released by the release lever 7, the spring 13 transmits the energy initially stored during the reset, to the plate 8, which causes the unlocking of the latch of the circuit breaker block, and thereby the opening of the contacts of the associated circuit breaker block. The return to the open position of the lever 11, the rod 10 and the hooking lever 9 is out of sync with the return of the plate 8 and the lever 7.
According to the invention, this plate 8 also comprises an arm 8a intended to cooperate with a torsion spring 15, said spring being mounted in compression by its two opposite ends 15a, 15b respectively on two parts of the device housing, in the disarmed state of the mechanism, and having an end 15b brought into abutment on the arm 8a of the plate 8 after triggering by displacement of the plate, so as to exert a force on the plate 8, after a trigger, sufficient to bring the pallet 6 in the aforementioned first position.

The Figures 1 and 2 show the trigger device in the standby state, in which the coil 4 of the electromagnet 3 is undervoltage, the mechanism 2 armed and the circuit breaker block in the closed position. The pallet 6 is permanently attracted in the position in which it is against the magnetic "U" 5 and the actuating lever 16 associated with the pallet 6 does not act on the release lever 7, which positively locks the mechanism 2 in the armed state. In this position, the additional spring 15 is supported by one 15a of its branches 15a, 15b, on a stud integral with the housing 1 and the other 15b of its branches, on the arm 8a of the plate 8, which maintains this spring 15 in the armed position thanks to the locking made by the release lever 7 between the handle 11, the rod 10 and the attachment lever 9. Thus, this additional spring 15 is stretched by the arm 8a in the spring position of the spring 13. In this position, the direction of the initial force F applied to the arm 8a of the plate is such that the torque transmitted to the arm by the additional spring 15 is low, as shown by the small ratio of distances d1 / d2 separating the direction D1 of the force mentioned above, the direction D2 of the straight line passing through the articulation axis X of the plate and parallel to the previous line D1, and the straight line D3 parallel to the two preceding ones passing through the axis of rotation of the spring 15.
On the figure 3 , the presence of a voltage fault across the coil 4 has caused the opening of the magnetic circuit 5 and thus the movement of the pallet 6 in the clockwise direction. During this movement, the actuating lever 16 associated with the pallet 6 is rotated in the same direction and, by its end portion 16a situated on the side opposite the pallet, actuates the release lever 7. The displacement of the latter causes the locking lever 9 to be unlocked, as shown in FIG. figure 3a from which it follows that the plate 8 and the lever 7 rotate under the effect of the aforementioned main spring 13, this displacement resulting in the unlocking and therefore the opening of the contacts of the associated circuit breaker block. In the position of the device illustrated on the figure 3 corresponding to a start of tripping, the torque transmitted to the mechanism by the additional spring 15 is the same as in the position of the previous figure, so as not to modify the external trigger characteristics, as represented by the distance d1 equal on the Figures 2 and 4 .
On the Figures 5 and 6 , the triggering process is at its critical point, the main spring 13 having transferred a large part of its energy, the arm 8a is in interference with the actuating lever 16 itself subjected to the contradictory effect of the spring 12. It is at this moment that the effect of the additional spring 15 produces its greatest torque on the plate 8, this being reflected on the figure 6 by a ratio d1 '/ d2' greater between the direction D1 of the force F, the direction D2 passing through the axis of rotation X of the plate and parallel to D1 and the direction D3 passing through the axis of the spring 15. In this position, the additional torque delivered by the spring 15 compensates for the energy loss involved by the compression of the spring 12.
Thus, while the spring 15 expands slightly during the tripping phase, the ratio of the lengths d1 '/ d2' between its own axis, its point of application on the plate 8 and the axis of rotation of the plate 8, tends to maximize its effect at the most critical moment of the triggering process.

On the Figures 5 and 6 , the handle 11 is still in the closed position and the latter and the link 10 are returning to a position corresponding to an open position as illustrated in FIGS. Figures 7 to 8 .

At the end of the rotary stroke of the plate 8, the torque transmitted by the additional spring 15 begins to decrease until it is reduced at the end of travel of the pallet, position in which the reel 4, if it is crossed again by a normal current, can attract the pallet 6 so as to keep closed the magnetic circuit.

On these Figures 7 to 10 , the device is in an open position, the contacts of the circuit breaker block being open. In this position, the additional spring 15 is prestressing, and its two ends 15a, 15b bear respectively on two parts of the housing. Indeed, during the opening movement of the plate, the arm has moved downwards, which has caused a displacement of the fulcrum of the second end 15b of the additional spring 15, a position in which he was resting on the arm, towards a position in which he is resting on the case. ( fig.9 ).

At this stage, the closing of the contacts of the circuit-breaker is authorized and rearming of the main spring 13 is achieved by operating the lever 11 towards the side opposite to that of the Figures 7 to 10 . The driving energy of the spring accumulated during the reset will be released again when the electromagnet will again have enough current to keep the magnetic circuit closed.

Thus, according to the invention, a torsion spring applies a torque to the arm of the plate in addition to the main spring of the mechanism plate.
The geometry of the arm and the additional spring and their arrangement is such that the additional torque delivered to the plate of the mechanism is low at the beginning of the opening stroke, so as not to change, thus disrupt or reduce, the external triggering characteristics. , strong at the moment of weakness identified from the mainspring, and weak at the end.
Thus, the torque transmitted to the plate by the torsion spring is maximum when the energy supplied by the mainspring is no longer sufficient to simultaneously supply the motive power minimum required for unlocking the circuit breaker and resetting the magnetic circuit. The additional energy is maximum when the resistance of the pallet is maximum.
Thus, the force / displacement characteristic provided by the mechanism at the circuit breaker is only slightly modified.

Thus, according to the invention, an auxiliary triggering device has been implemented which makes it possible to mechanically close the magnetic circuit of the electromagnet in order to limit the amount of current required for the magnetic bonding of the pallet, the force / displacement characteristic provided by the mechanism. being only slightly modified.
This compensates for the loss of motive power without altering the adaptability of the mechanism of the auxiliary to that of the circuit breaker. The effort required to trigger the mechanism is directly related to the driving torque of the main spring.
All common parts remain compatible with other auxiliaries. Only the additional spring is added or not, depending on the characteristics of the auxiliary device to be mounted.
By removing the spring, the same mechanism can be used for example as a remote trigger.
Note that although the embodiment described relates to an auxiliary tripping device with no voltage, the invention is also applicable to any auxiliary trigger device in which it is necessary to bring a pallet in position after a trigger.

Of course, the invention is not limited to the embodiment described and illustrated which has been given by way of example.

Claims (5)

1. An auxiliary trip device housed in a modular insulating case (1) designed to be adjoined to a circuit breaker unit, said trip device comprising:

   - an operating mechanism (2) having a trip link designed to act on the trip latch of the circuit breaker unit, said mechanism comprising a transmission rod (10) coupled to a handle (11), a support plate (8) fitted rotating in the case and having a breakable mechanical link with the transmission rod (10), and a trip lever (7) controlled by an electro-magnet (3) to cause breaking of the mechanical link, in the event of a fault, resulting in automatic tripping of the mechanism independently from the handle (11) and actuation of the trip latch of the associated circuit breaker unit, said mechanism being biased to a loaded position by the handle (11) against the force of a return spring called first spring (13) designed to drive the support plate (8) to the unlatched position of the circuit breaker unit in case of tripping,

   - an electromagnet provided with an excitation coil (4) and with a magnetic circuit with a movable armature (6) which can occupy either a first position separated from the magnetic circuit due to the action of a return spring called second spring (2) or a second position drawn towards the magnetic circuit by electromagnetic attraction when excitation of the coil (4) takes place, said armature (6) collaborating with the above-mentioned trip lever (7), characterized in that it comprises

   - means for biasing the armature (6) to the second position after tripping, these means comprising an arm (8a) supported by the support plate (8), and

   - a spring called third spring (15) stretched taut by the arm (8a) of the support plate (8) in the loaded position of the mechanism, said spring called third spring (15) being designed to exert a force on the arm of the support plate when it relaxes, after latching of the support plate has been released, so as to bias the movable armature formed by a blade (6) to the above-mentioned second position drawn towards the magnetic circuit (5).
2. The auxiliary trip device according to claim 1, characterized in that the spring called third spring (15) and the arm (8a) of the support plate (8) are shaped and arranged in such a way that, at the beginning of tripping, the direction of the initial force F applied to the arm (8a) of the support plate (8) is such that the torque transmitted to the arm of the support plate is weak, that in the course of movement of the arm following relaxation of the spring (15), the direction of the force of the spring on the arm changes so that the torque transmitted to the arm is amplified in an intermediate phase when the spring called first spring no longer suffices to provide the minimum driving force required both to release latching of the trip latch of the circuit breaker unit and to reload the magnetic circuit, and that at the end of tripping the torque transmitted to the arm is weak.
3. The auxiliary trip device according to claim 1, characterized in that the spring called third spring (15) is a torsion spring.
4. The auxiliary trip device according to claim 3, characterized in that the spring called third spring (15) comprises one end (15a) pressing on the case (1) and one end (15b) pressing on the arm (8a) of the support plate (8) in a loaded position of the mechanism, the two ends (15a,15b) of the spring (15) being pressing on the case (1) in the tripped position of the mechanism, changing of the pressing point of the second end (15b) of the spring from a position pressing on the arm (8a) to a position pressing on the case (1) having been caused by the movement of the support plate when tripping takes place or when moved to the rest position by the handle.
5. The auxiliary trip device according to any one of the foregoing claims, characterized in that it is an undervoltage trip device.

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