EP3091557B1 - Device for controlling an electrical protection unit and electrical protection unit comprising same - Google Patents

Description

TECHNICAL AREA

• une biellette de transmission accouplée à la manette,
• un dispositif de support du contact mobile comportant une platine montée à rotation sur un pivot et ayant une liaison mécanique brisable avec la biellette de transmission, et
• un levier de déclenchement commandé par un déclencheur pour provoquer en cas de défaut la rupture de la liaison mécanique, entraînant le déclenchement automatique du mécanisme indépendamment de la manette et la séparation des contacts,
• la liaison mécanique brisable étant formée par un cran de retenue du levier de déclenchement coopérant avec un crochet d'accrochage monté à pivotement sur un axe de la platine, la rupture de la liaison mécanique correspondant au déverrouillage de l'accrochage, la biellette de transmission, en position de verrouillage de l'accrochage prenant appui au moins en partie sur la platine.

The present invention relates to a control device of an electrical protection device housed in an insulating housing enclosing a pair of fixed and movable contacts, said movable contact being operable either manually via a joystick or automatically, comprising

• a transmission link coupled to the joystick,
• a device for supporting the movable contact comprising a plate rotatably mounted on a pivot and having a breakable mechanical connection with the transmission link, and
• a release lever controlled by a trigger to cause, in the event of a fault, the breaking of the mechanical link, causing the automatic triggering of the mechanism independently of the handle and the separation of the contacts,
• the breakable mechanical connection being formed by a catch of the release lever cooperating with a hook hook pivotally mounted on an axis of the plate, the breaking of the mechanical connection corresponding to the unlocking of the attachment, the transmission link , in locking position of the latch bearing at least partly on the plate.

The present invention also relates to an electrical protection apparatus comprising such a control device, and in particular a low-voltage circuit breaker.

STATE OF THE PRIOR ART

The patent is known FR 2,589,627 of the aforementioned kind in which the transmission rod cooperates with the platen bearing on it. In this device, the force of the mechanism is taken up two thirds on the plate and a third on the trigger bar. There is no multiplier effect.

The patent is also known FR 2,616,583 describing a control mechanism of a miniature electric circuit breaker having the features mentioned above.
In this document, the assembly comprising the transmission link, the hook, and the trip lever is a reduction stage allowing a reduction of the triggering force. In this mechanism, the force of the rod exerts a torque on the hook only.
Since all the effort of the rod is concentrated on the hook, significant efforts are generated on the bar.
The patent is also known FR 2 914 485 in which the effort of the connecting rod is distributed on the plate and on the hook.
So we get less stress on the bar. Thus, the triggering forces are reduced.
However, in some devices of the type recently described above, the force exerted by the rod is two to three times greater than that usually exercised in this type of device, which can be of the order of 100N. In this case, there is therefore an increased risk of matting the support zone of the rod on the plate, and significant friction coefficients during a trip.

SUMMARY OF THE INVENTION

The present invention solves these problems and proposes a device for controlling an electrical protection device, as well as an electric protection device comprising it, making it possible to reduce the triggering forces and to eliminate the non-triggering phenomena due to a matting process. the support zone of the plate by the transmission rod in the so-called locking position of the control device corresponding to a closed position of the contacts of the device.

For this purpose, the subject of the present invention is a control device of the kind mentioned above, this device being characterized in that it comprises a rigid insert mounted on the plate and intended to be interposed between the transmission link and a transmission zone. the plate constituting a bearing zone of this link on the plate in the aforementioned locking position, and means for maintaining the position of said insert without play with respect to said plate.
Thanks to these characteristics, there is no more matting of the support zone on the plate by the connecting rod, resulting in a reduction of the friction coefficients during a trip.

Thus, too large triggering efforts as well as "no trigger" due to matting of the plate by the connecting rod are removed.

According to a particular characteristic, this rigid insert comprises a substantially V-shaped folded sheet, this sheet being intended to be fixed around an axis-forming portion of the rod, this portion of an axis-forming rod being intended to be fixedly mounted in the plate. and extending substantially perpendicularly to the plane of said V.

According to another feature, the aforementioned rod portion is mounted tightly in the plate.

According to another characteristic, the assembly of the aforementioned insert on the rod portion is performed by laser welding.

According to another characteristic, said insert is mounted in a recess formed in the plate, so that the plane in which said V extends is substantially parallel to the plane of a face of the plate located opposite the transmission rod .

According to another characteristic, the aforementioned holding means comprise a projection provided on one face of the above-mentioned recess and intended to bear against an outer face of one of the branches of said V, said boss being intended to serve as a reference angularly to the assembly comprising the rod portion and the insert, said boss being intended to cooperate with a projecting portion belonging to another face of the above-mentioned recess, opposite to the preceding one, this protruding portion being intended for come to bear against an inner face of this same branch of the aforementioned V, opposite to the aforementioned outer face, said boss being intended to serve as an angular reference to the assembly comprising the rod portion and the insert relative to the axis of the rod, and the above-mentioned projecting part cooperating with the above-mentioned boss so as to immobilize the insert in rotation with respect to the platinum around it of the axis of the aforementioned rod portion.
Thanks to these characteristics, the insert is maintained and positioned in the plate without play, which prevents the matting of the plate.

Advantageously, this projecting portion comprises a tip.

Advantageously, this insert is a metal insert.

According to a particular characteristic, the rod is the needle around which the aforementioned hook is rotatably mounted relative to the plate.

According to a particular embodiment, the aforementioned transmission rod is supported both on the hook and on the plate in the locking position of the hook.
According to this embodiment, the force of the connecting rod is distributed on the plate and on the hook. So we get less stress on the bar.
Thus, the tripping efforts are further reduced.

The present invention also relates to an electrical protection apparatus comprising a control device comprising the previously mentioned features taken alone or in combination.

Advantageously, this apparatus is a low-voltage circuit breaker.

• La figure 1 est une vue partielle, en plan, illustrant la partie intérieure d'un disjoncteur équipé d'un dispositif de commande selon une réalisation particulière de l'invention, en position ouverte des contacts de la manette,
• Les figures 2 et 3 sont deux vues en perspective d'une platine, disposées respectivement selon deux orientations différentes, avant la mise en place de l'insert selon l'invention,
• La figure 4 est une vue de face de l'insert selon l'invention, monté autour de la tige formant axe de rotation du crochet,
• Les figures 5 et 6 sont respectivement une vue de face et une vue en perspective de cette même platine après le montage de l'insert et de la tige dans la platine, et
• Les figures 7,8 et 9 sont des vues partielles en plan, illustrant une partie du mécanisme de commande, comportant en plus des éléments illustrés sur les figures 5 et 6, le crochet, la bielle de transmission et le levier de déclenchement, respectivement en position ouverte, fermée ou déclenchée dudit mécanisme.

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 partial view, in plan, illustrating the inner part of a circuit breaker equipped with a control device according to a particular embodiment of the invention, in the open position of the contacts of the joystick,
• The Figures 2 and 3 are two perspective views of a plate, respectively arranged in two different orientations, before the introduction of the insert according to the invention,
• The figure 4 is a front view of the insert according to the invention, mounted around the rod forming the axis of rotation of the hook,
• The Figures 5 and 6 are respectively a front view and a perspective view of the same plate after mounting the insert and the rod in the plate, and
• The Figures 7,8 and 9 are partial plan views, illustrating part of the control mechanism, including in addition elements illustrated on the Figures 5 and 6 , the hook, the connecting rod and the trigger lever, respectively in the open position, closed or triggered said mechanism.

On the figure 1 , we see a miniature electric circuit breaker 1 molded insulating housing comprising a control device 2 according to the invention. This device comprises a support device 3 of the movable contact 4, said mobile contact 4 cooperating with a fixed contact 5.
An opening 7 is provided in the front face 8 of the housing for the passage of a lever 6 mounted pivotally limited on an axis 11 of the housing between a closed position in which the contacts 4,5 are closed, and a position of opening corresponding to the separation of contacts 4,5. The lever 6 is equipped with an internal base 9 coupled to a transmission rod 10 to form a toggle device whose articulation 12 is eccentric with respect to the fixed axis 11 of the lever 6.
The lever 6 is biased in the trigonometric direction towards the position of opening of the contacts by a return spring (not shown). The fixed contact 5 is secured to the casing of the electromagnetic trip unit. The movable contact 4 is fixed to the support device 3 of the movable contact 4, said support 3 being articulated on a pivot 40, the rotating plate 15 being rotatably mounted around the pivot 14.
A triggering lever 16 controlled by the striker of the electromagnetic release, the bimetallic strip of the thermal release (not shown) or an external auxiliary, is pivotally mounted on an axis 17 carried by the plate 15 with a predetermined offset relative to the aforementioned pivot 14 .

• Tout d'abord, l'on réalise la fixation de la tôle 30 sur la tige 32, avantageusement au moyen d'une soudure laser ou tout autre moyen approprié. Puis cet ensemble est monté sur la platine 15 par le montage serré de la tige dans un orifice correspondant de cette platine.

Puis, la tôle en v est positionnée sur la face extérieure de la platine, l'une des branches étant interposée entre le bossage 34 et la pointe 37.A breakable mechanical connection is provided between the transmission link 10 and the drive plate of the contact support device 3 4.
In the locked position, the link allows the manual control of the mechanism by the lever 6. The movement of the trigger lever 16 to the triggered position under the action of the triggers, causes the momentary rupture of the mechanical link, causing the automatic triggering of the mechanism, independently of the lever 6. The trigger lever 16 is associated with a return spring 27 to ensure the automatic restoration of the mechanical link when the handle 6 is actuated to the open position, following a triggering of the fault mechanism.
The breakable mechanical link comprises a hook 19 pivotally mounted on an axis 20 of the plate 15. Opposite this axis, the spout 21 ( fig.4 ) of the hook 19 cooperates in the locked position of the connection with a retaining notch 22 located on the arm of the trigger lever 16. The transmission rod 10 is coupled to the hook 19 and the plate 15 at a hinge point likely to move during the trip in two consecutive openings 26 of the plate 15, openings of which only one is visible on this figure 1 . This point of articulation is located between the hinge axis 20 of the hook 19 on the plate and the spout 21 of the hook hook. The link is a reduction stage in the kinematic chain of the mechanism, allowing a reduction of the triggering force from the magneto-thermal trigger.
The hook 19 also has a bean-shaped opening or V 25 which, with the apertures 26 of the plate, are intended to allow the rotation of the contact holder plate 15, during a trip, while the rod 10 is blocked by the handle 6, itself held in the closed position of the contacts. For a more detailed description of the operation of this device, refer to FR 2 914 485 . The opening 26 provided in the plate 15 also guides the stroke of the link when the handle returns to the open position of the contacts after a trip.
A bias spring 27 with two branches 28,29 is installed around the axis 17 on the lever 16. One of the branches 28 is intended to return the release lever 16 to its initial position while the other branch 29 polarizes the hook 19 in a chosen preferential position of so as to create between the lever 16 and the hook 19 a clearance sufficient to allow the attachment.
According to the invention and as illustrated more particularly on Figures 2 to 6 , this control device 2 comprises an insert 30 adapted to be mounted and fixed without play in a recess 31 provided in the plate, this insert 30 being intended to be interposed between the transmission rod 10 and a fixed part 32 of the plate 15 so as to prevent the matting phenomena of the plate 15 by the rod 10, in the locking position of the control device or open position of the contacts, that is to say in the position in which said link 10 is supported by both on the plate 15 and on the hook 19, position illustrated on the figure 8 .
Preferably, this insert 30 is metallic. According to the preferred embodiment described, this insert 30 takes the form of a V fixed preferably by means of a laser weld ( fig.4 ) at two locations respectively on two inner faces of said V, a rod member 32, this member being fixed to the plate 15 so that the axis of the rod extends substantially perpendicular to the plane of the face 33 the plate 15 located on the side of the transmission rod 10, as illustrated on the Figures 2 to 9 .
According to this preferred embodiment illustrated, this rod 32 forms an axis about which the hook 19 is rotatably mounted relative to the plate 15.
The means for holding the insert 30 in position relative to the plate 15 comprise a boss 34 formed on a face 35 of the recess 31 of the plate 15 intended to receive the insert, this boss being intended to bear on an outer face 36 of one of the branches of the V formed by the insert. This boss 31 is intended to cooperate with a pointed portion 37 provided on another face 38 of the recess 31, this tip-shaped element being intended to be brought into abutment on an inner face 39 of the same branch of the V. This boss 34 and this point 37 make it possible to ensure in combination a holding in position of the insert 30 in the housing 31 by providing this insert 30 a fixed position relative to the plate 15.
The assembly of this assembly on the plate 15 is as follows:

• First of all, the sheet 30 is fastened to the rod 32, advantageously by means of a laser weld or any other suitable means. Then this assembly is mounted on the plate 15 by the tight fitting of the rod in a corresponding hole of this plate.

Then, the v-shaped plate is positioned on the outer face of the plate, one of the branches being interposed between the boss 34 and the tip 37.

The operation of the control device as described above will be described hereinafter with reference to the figures.
On the figures 1 and 7 , the control device 2 is in a position of the open contacts, the lever 6 being in the open position.
In this position, the transmission rod 10 exerts no effort on the plate.
When the lever 6 is actuated to close the contacts, the latter moves the rod 10 which bears on the plate 15 via the insert 30, and on the hook 19. The hook 19 is locked on the trigger bar (or lever) 16. ( fig.7 ).
The rod 10 bears on the plate 15 and on the hook 19, pivots the plate 15 about its axis 20 until the contacts 4,5 close.
The rod continues its race until the dead center of the toggle formed by the lever 6 and the link 10 is crossed. Then, the mechanism takes the equilibrium position which keeps the contacts closed. The position shown in FIG. figure 8 . In this position, the rod 10 exerts a force F distributed according to a force F1 exerted on the insert 30 and a force F2 exerted on the release lever 16.
When it is desired to open the contacts 4.5 manually, the handle 6 is actuated until it crosses the dead center of the toggle in the opposite direction. The mechanism then joins the equilibrium position, the contacts being open, when the handle reaches the end of its stroke, the position represented on the figures 1 and 7 .
When the contacts are closed and the trigger bar or lever 16 is actuated, the hook 19 is unlocked, but the lever 6 does not return immediately to its open position.

The balance of forces exerted by the rod 10 on the mechanism is broken. The plate 15 rotates about its axis 14 and opens the contacts, the position shown on the figure 9 . The opening 25 ( fig.1 ) provided inside the hook 19, allows the rotation of the hook about the axis 20,32 and this opening 25 of the hook and the openings 26 of the plate 15, allow the rotation of the plate, the lever being still held in closed contact position.
Then, the spring of the joystick brings it in open contacts position and the rod returns the hook in the initial position. The biasing spring 27 of the hook and resetting of the bar places them in a position to lock the hook on the bar when the handle is actuated to close the contacts. The openings 26 provided in the plate 15 participate in guiding the link 10 so as to bring it back into the support position on the plate.
Thus, in the normal operating position of the circuit without fault in the circuit, position illustrated on the figure 8 , the rod 10 bears on the contact holder plate 15 according to F1 through the insert 30, and on the locking hook 19 according to F2, the relative positions of the two bearing surfaces and the ratio of the arms Leverage is optimized so that the force that locks the hook is reduced to a minimum.
Thus, the system comprises two stages of reduction. According to the first, the force of the mechanism is taken up largely on the plate and in a smaller part on the hook. According to the second, by a set of lever arms on the hook, the force is multiplied on the trigger lever.

Due to the presence of this metal insert 30, the matting phenomenon of the plate 15 no longer occurs, which prevents the occurrence of excessive tripping forces, see the absence of trigger 16. When the invention is used in an electrical protection device as described and illustrated in the foregoing, in which the force of the connecting rod is distributed both on the plate and on the hook, we already obtain a lower trigger force on the bar because of this distribution of the effort of the connecting rod. Thus, the tripping efforts are already reduced. then the use of a metal insert according to the invention in such an apparatus, we obtain a further reduction of the triggering forces by the fact that the matting of the plate is prevented.
The use of such an insert is particularly advantageous when the force exerted by the rod is important, for example 100N.
In such devices, it was generally necessary to provide specific differential protection devices because the triggering forces remained important.
By further reducing these triggering forces by the invention, it is then possible to use standard trigger devices.
The invention therefore advantageously applies to such devices in which the force of the link is exerted both on the plate and on the hook, but not exclusively. Indeed, the invention also applies advantageously to devices in which the force of the link applies only to the plate for example, with the result of reducing the triggering forces.
Thus, thanks to the invention, it solves the problem of lack of tripping circuit breakers through a set comprising an axis needle and a V-shaped sheet easy to make and assemble, this set to obtain a reduction 50% of the tripping efforts of a circuit breaker with a rating of up to 120A.
It should also be noted that this reduction of the tripping forces also makes it possible to obtain an improvement in the thermal adjustment, because the efforts being less important, there is less difficulty in finding the right bimetal shade.

Claims (12)

1. Device (2) for controlling an electrical protection unit housed in an insulating housing (1) containing a pair of fixed (5) and movable (4) contacts, said movable contact capable of being operated either manually via a control lever or automatically, comprising

   - a transmission link (10) coupled to the control lever,

   - a device (3) for supporting the movable contact comprising a plate (15) rotatably mounted on a pivot (14) and having a breakable mechanical connection with the transmission link, and

   - a trip lever (16) controlled by a tripping device in order to break the mechanical connection in the event of a fault, leading to the automatic release of the mechanism independently of the control lever and separation of the contacts,

   - the breakable mechanical connection being formed by a retaining notch (22) of the trip lever collaborating with a catch (19) pivotably mounted on a pin (20) of the plate (15), the breakage of the mechanical connection corresponding to unlocking of the catch, the transmission link (10), when the catch is in the locked position, resting at least on the plate,

   characterized in that it comprises a rigid insert (30) mounted on the plate (15) and intended to be inserted between the transmission link (10) and a zone of the plate (15) that constitutes a zone in which this link bears against the plate in the aforementioned locked position, and means (34, 37) for keeping this insert (30) in position with respect to said plate (15) without play.
2. Control device according to Claim 1, characterized in that this rigid insert (30) comprises a piece of sheet metal substantially bent into a V shape, this sheet intended to be secured around a rod portion forming a shaft (32), this rod portion (32) intended to be solidly mounted in the plate (15) and extending substantially perpendicularly to the plane of said V.
3. Control device according to Claim 2, characterized in that the aforementioned rod portion (32) is tightly fitted in the plate (15).
4. Control device according to Claim 2 or 3, characterized in that the assembly of the aforementioned insert (30) on the rod portion (32) is made by laser welding.
5. Control device according to any one of the preceding claims, characterized in that said insert (30) is mounted in a recess (31) formed in the plate (15), such that the plane in which extends said V is substantially parallel to the plane of one face (33) of the plate (15) located opposite the transmission link (10).
6. Control device according to any one of Claims 1 to 5, characterized in that the aforementioned retaining means comprise a boss (34) provided on one face (35) of the aforementioned recess (31) and intended to abut against an outer face (36) of one of the branches of the aforementioned V, said boss (34) intended to serve as an angular reference to the assembly comprising the rod portion (32) and the insert (30), said boss (34) being intended to cooperate with a projecting part (37) belonging to another face (38) of said aforementioned recess (31), opposite the previous one, this projecting part (37) intended to bear against an inner face (39) of this same branch of the aforementioned V, opposite the aforementioned outer face (36), said boss (34) intended to serve as angular reference to the assembly comprising the rod portion (32) and the insert (30) relative to the axis of the rod (32), and the aforementioned projecting part (37) cooperating with the aforementioned boss (34) so as to produce a rotational locking of the insert (30) relative to the plate (15) about the axis of the aforementioned rod portion (32).
7. Control device according to Claim 6, characterized in that this projecting part comprises a point (37).
8. Control device according to any one of the preceding claims, characterized in that the aforementioned insert (30) is a metallic insert.
9. Control device according to any one of the preceding claims, characterized in that the rod (32) is the needle around which the aforesaid catch (19) is rotatably mounted with respect to the plate (15).
10. Control device according to any one of the preceding claims, characterized in that the above-mentioned transmission link (10) is supported on both the catch (19) and the plate (15) in the locking position of the catch (19).
11. Electrical protection unit comprising a control device according to any of the preceding claims.
12. Electric protection unit according to Claim 11, characterized in that it is a low voltage circuit breaker.

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