EP0218497A1 - Protective circuit breaker with a resilient link - Google Patents

Abstract

1. Protection switch for an electric installation comprising, in an insulating case (11) : - at least one fixed contact (C2) and a mobile contact (C1) which cooperate and form a current path which can be interrupted in response : - either to the actuation of a magnetic (DM) and/or thermal (DT) automatic tripping member, - or to the actuation of a manuel tripping and resetting control member (M), - a lock comprising : - a hook (12) which can be moved by the automatic tripping member (DM, DT), - a tripping lever (18) having at a first end a nose-piece (22) cooperating with the hook (12) and connected to the manuel control member (M) so as to pivot, either by bearing on the hook (12) so as to cause voluntary opening of the contacts or on a mowable shaft (19) connected to the manual control member (M) for causing automatic tripping ; this tripping lever (18) being connected to a contact piece (32) mounted for pivoting on a pin (30a) belonging to a rigid conducting piece (30) fixed with respect to the case (11) and fast with a terminal (B1) of the switch, by means of a spring (R) forming a resilient transmission link between the lever (18) and the contact piece (32) and contributing to sudden opening of the contact piece (32) characterized in that the resilient link (R) consists of a hairpin spring in the shape of a V, a first leg (28) of which is applied to a second end of the tripping lever (18) and the other leg (29) of which cooperates with two rests situated on each side of the pin (30a), namely an opening rest (36) and a closure rest (31).

Description

• - au moins un contact fixe et un contact mobile coopérant pour former un chemin de courant interruptible en réponse :
  • . soit à l'actionnement d'un organe magnétique et/ou thermique de déclenchement automatique sur défaut,
  • . soit à l'actionnement d'un organe de commande manuelle de déclenchement et de réarmement,
• - une serrure comprenant :
  • . un crochet déplaçable par l'organe de déclenchement sur défaut,
  • . un levier de déclenchement muni à une première extrémité d'un becquet coopérant avec le crochet et relié à l'organe de commande manuelle, de manière à pivoter, soit en prenant appui sur le crochet pour effectuer une ouverture volontaire des contacts, soit sur un axe déplaçable relié à l'organe de commande manuelle pour effectuer un déclenchement automatique.

The present invention relates to a protective switch for electrical installation, comprising in an insulating housing:

• - at least one fixed contact and one movable contact cooperating to form an interruptible current path in response:
  • . either on the actuation of a magnetic and / or thermal organ for automatic tripping on fault,
  • . either the actuation of a manual triggering and resetting control member,
• - a lock comprising:
  • . a hook movable by the trip device on fault,
  • . a trigger lever provided at one end with a spoiler cooperating with the hook and connected to the manual control member, so as to pivot, either by bearing on the hook to effect voluntary opening of the contacts, or on a movable axis connected to the manual control member to carry out an automatic release.

Such a protection switch is described in patent application EP-0 047 847. This switch has a tension spring anchored, on the one hand, on the manual control member at an eccentric point thereof and, d on the other hand, on a contact piece itself articulated with respect to the trigger lever. The device in question requires a carefully calibrated and positioned spring, as well as a triangular kinematic connection of the manual member-lever, manual member-contact piece and lever-contact piece; an anchoring and a guide must, moreover, be provided for the spring in the manual control member and require an oversizing of the latter.

The object of the present invention is in particular to give a protection switch of the type mentioned above great simplicity of design and assembly, while retaining a small footprint for the lock-manual control member assembly.

Another purpose is to provide a protection switch with high trigger sensitivity.

To this end, the invention relates to a protection switch of the above type, in which the trigger lever is connected to a separate contact piece by means of a spring constituting, on the one hand, an elastic transmission link between the lever and the contact piece and contributing, on the other hand, to the abrupt opening of the contact piece.

An additional spring may be provided to contribute to the opening of the contact piece, but this opening is preferably produced by the aforementioned single elastic link.

The contact piece is advantageously pivotally mounted on a pin fixed relative to the housing, the elastic link cooperating with at least one support provided on the piece of contact to keep it applied to the fixed pin. As soon as the fixed support is part of a rigid and electrically conductive part integral with one of the terminals of the switch, the spring makes it possible to ensure a satisfactory electrical connection between the terminal and the contact part without requiring braid or other flexible conductive medium.

The elastic link is, for example, a leaf or pin spring in the shape of a V or a U. In its embodiment of a V pin, the spring has a first branch of the V applied to a second end of the lever release and a second branch of the V applicable on a closing support and on an opening support of the contact part.

The hook can advantageously constitute a spreader interposed between the core of the magnetic trip device and the bimetallic strip of the thermal trip device and arranged so that the beginning of deflection of the bimetallic strip causes a slight pivoting of the hook and a slight plunging of the core. In addition, a return spring associated with the core of the magnetic trigger preferably constitutes a means for returning the hook to its position for hooking the spoiler.

• La figure 1 représente schématiquement en élévation avec arrachement partiel du boîtier l'interrupteur de protection en position de fermeture des contacts ;
• La figure 2 montre de même l'interrupteur en position de fin de déclenchement automatique sur défaut ou respectivement en position d'ouverture manuelle;
• Les figures 3 et 4 représentent le levier de déclenchement et la pièce de contact de l'interrupteur des figures 1 et 2 ;
• La figure 5 montre en perspective un détail de montage de la pièce de contact et de la biellette élastique.
• Les figures 6 à 8 représentent l'extrémité d'accrochage du levier de déclenchement respectivement dans les positions d'accrochage (position armée), de début de déclenchement automatique magnétique et de fin de déclenchement automatique.

Other advantages and characteristics of the invention will appear on reading the description which follows with reference to the appended drawings and which relates to a nonlimiting exemplary embodiment.

• Figure 1 shows schematically in elevation with partial cutaway of the housing the protective switch in the closed position of the contacts;
• FIG. 2 likewise shows the switch in the end position of automatic tripping on fault or respectively in the manual opening position;
• Figures 3 and 4 show the release lever and the contact part of the switch of Figures 1 and 2;
• Figure 5 shows in perspective a mounting detail of the contact piece and the elastic link.
• FIGS. 6 to 8 show the hooking end of the trigger lever respectively in the hooking positions (armed position), of the start of automatic magnetic triggering and of the end of automatic triggering.

The protective switch 10 shown in the figures is a circuit breaker having an electrically insulating casing 11, capable of being fixed by means of suitable snap-fastening members on a support such as a perforated plate or a standardized rail and provided with terminals Bl, B2 respectively connected to a movable contact Cl and to a fixed contact C2. One could of course provide contact bridges C1 and C2.

The switch 10 comprises a manual control member M constituted by a rotary button of axis 01 and an automatic trigger member D provided with a magnetic trigger DM and a thermal trigger DT; the members M and D are mounted in the housing and are capable of separating the contact Cl from the contact C2 and therefore of opening the current path Bl, B2 by means of a lock in response to the detection of an electrical fault via DM or DT triggers or respectively in response to a manual command. An interrupting chamber A is bordering on the contacts C1, C2.

The output element of the triggering member D is a hook 12 rotatably mounted about a fixed axis 02 relative to the housing and cooperating by a fork 13 which has two fingers 13a and 13b with a stock 14 with respective surfaces d 'support 14a and 14b. The butt 14 is located at the end of a plunger core 15 of the magnetic trip device DM. The hook 12 further cooperates by means of a finger 16 with a deformable bimetal lever 17 of the thermal trip device DT.

The lock comprises a trigger lever 18 in the form of a pendulum made of insulating material. The lever 18 is directly mounted on a tenon 19 of the manual member M and has, for this purpose, a slide 20 slightly inclined (FIG. 1), or even parallel (FIG. 2), with respect to the front face 21 of the circuit breaker, and cooperating with said stud. The tenon 19 is movable from a position X1 to a position X2 and vice-versa, while the slide 20 is curved at 20a at its right end (Figure 3). The lever 18 comprises, at a first end, a spoiler 22 resting on a support 23 of the hook (FIG. 6), this support being erasable as a result of the pivoting of the hook to authorize the tilting of the lever 18 in response to an electrical fault detected by the DM or DT trigger.

The lever 18 comprises, towards its second open end or head 24, a guide groove 25 substantially perpendicular to the face 21 and cooperating with a guide pin 26 formed in the housing. Near the upper end of the head 24 of the lever 18, a fulcrum or anchor point 27 is provided for a pin-shaped spring R in the shape of a V.

The first branch 28 of the spring R is thus applied to the displaceable anchor point 27 in order to tend to tilt the lever 18 clockwise: the second branch 29 of the spring R is fixed in rotation to a pin 30a formed on a conductive part rigid 30 which is fixed relative to the housing and which is secured to the terminal Bl. The branch 29 is firstly applied at its end on a closing support 31 of a contact piece 32 separated from the lever 18 and constituting or carrying the contact Cl, second applicable near the tip of the V on an opening support 36 of the part 32, the supports 31 and 36 being located on either side of the fixed pin 30a. The application of the brahche 29 on the closing support 31 ensures the closing of the contact C1 and its pressure on the contact C2; the application of the branch 29 on the opening support 36 allowing the opening of the contact Cl. The direction of rotation of the contact piece Cl depends on the application of the differential force of the branch 29 on the one or the other support 31, 36, this being a function of the position of the anchor point 27 of the branch 28.

The manual control button M has a manual grip 33, the pin 19 is located substantially opposite the grip 33 relative to the axis 01 and at a distance from this axis allowing amplification of effort. A return spring 34 is associated with the button M to assist the latter during a manual opening command and to call it back to the stop position during a trip on fault.

It should be noted that the DM trigger trigger comprises a spring 35 urging the core 15 so that the butt 14 of the latter pushes the finger 13a of the hook 12 in order to return the latter to the armed position of FIGS. 1 and 6.

The hook 12 advantageously constitutes a spreader interposed between the magnetic core 15 and the bimetallic strip 17, so that the beginning of deflection of the bimetallic strip causes a very slight counterclockwise pivoting of the hook and therefore a slight plunge of the core. In this way, the trigger intensity threshold of the DM trigger is lowered; an overload detected by the bimetallic strip of the thermal release therefore causes greater sensitivity of the magnetic release.

The finger 16 of the hook has an extension 37 located behind the bimetallic strip and provided with marks 16a which facilitate the adjustment of the bimetallic strip.

The operation of the device described is as follows: In the latching position (Figure 1), the movable contact C1 is applied against the fixed contact C2 as a result of the force applied counterclockwise by the spring R on the support 31 of the contact piece 32. The circuit Bl, Cl, C2, B2 is therefore closed.

In this position, the manual control button M in abutment on the housing occupies a position such that its tenon 19 is in the position denoted Xl at the right end 20a of the slide 20. The spoiler 22 of the lever 18 is hooked on the support 23 of the hook 12, which is held in the position indicated in FIG. 1 by the spring 35 of the magnetic trip device DM.

The spring R biases the lever 18 to make it tilt clockwise around the hinge pin 19, but is prevented by the above attachment. The upper end of the groove 25 of the lever 18 is against the guide pin 26.

Following a trip on fault detected by the magnetic or thermal trip device DT, the hook 12 pivots counterclockwise and its bearing surface 23 emerges from the spoiler 22 by releasing the lever 18 (FIG. 7). The latter pivots clockwise around the tenon 19 then occupying the position X1 under the effect of the upward stress exerted by the spring R on its anchor point 27. The branch 28 of the spring rises; the branch 29 which is integral with it is driven and is applied to the drive support 36 provided on the contact piece 32 and rotates the latter suddenly clockwise to open the contact C1.

At the end of tripping (FIG. 2), the lower end of the groove 25 abuts against the pin 26; due to the circuit being cut off, the core 15 of the magnetic trip unit returns to the high position and recalls the hook 12 in the armed position (Figure 8). It should also be observed that, during the triggering process, the movement of the lever 18 allows the button M to pass from the on position to the off position under the effect of its spring 34 and this, thanks to the overcoming of the obstacle constituted by the transition 20b of the slide 20 by the tenon 19. In addition, at the end of triggering, the lever 18 is brought into the position illustrated in FIGS. 2 and 8 where there is a small clearance between the spoiler 22 of the lever 18 and support 23 of hook 12.

To carry out a voluntary opening of the contacts, the user manually controls the button M to bring it by clockwise pivoting around 01 from its position in FIG. 1 to the position in FIG. 2, that is to say for carrying the post 19 from position Xl to position X2.

The hook 12 remains stationary and the spoiler located at the right end of the lever 18 remains hooked on the support 22, the latter therefore serving as a tipping point for the lever.

The slide being slightly curved, the beginning of the rotation of the button M determines a counterclockwise tilting of the lever 18 which reinforces the crushing of the V of the spring R and therefore increases the elastic energy of the latter; then after the transition 20b of the slide 20 has been exceeded by the tenon 19, the rotation of the button M causes a sudden clockwise tilting of the lever 18, so that the anchor point 27 of the spring R rises; the branch 28 thereof rises and drives the branch 29 which causes a decrease in the contact pressure of Cl on C2, then by applying to the support 36 drives the part 32 and causes an abrupt separation of Cl vis- opposite C2 to the open position illustrated in Figure 2.

At the end of voluntary opening, the lower end of the groove 25 abuts against the pin 26. Another stop could, of course, be provided in the housing to limit the movement of lever 18.

The hook is reset automatically under the effect of the return of the magnetic core to its upper position. It is sufficient to reset the switch to rotate the manual control button counterclockwise around the axis 01 from the "off" position (figure 2) to the "on" position (figure 1); the lever 18 and the branch 28 of the spring are thus lowered, so that the branch 29 urges the closing support 31 of the contact piece 32 until the application of C1 to C2; the separation of the branch 29 from the drive support 36 authorizes the contact pressure overtravel. The spoiler 22 comes to hang on its support 23. At the end of rearming, the tenon 19 is housed in the curved end 20a of the slide 20, so that the button M is forced to remain in the on position.

A trigger display element can be provided on the head 24 of the lever 18 so that its displacement opposite a window formed in the recess of the front face 21 of the housing signals the trigger.

Marks 16a are advantageously provided on the finger 16 of the bimetallic strip 17 in order to assist an operator during the process of adjusting the bimetallic strip.

It goes without saying that modifications can be made to the embodiment described without departing from the scope of the invention. The manual control member M, represented in the form of a pivoting button, could be produced in the form of a pusher. The actuation of the member M can be carried out from a polar device or additive close to the protection switch considered. The described elastic link constitutes the only means of mechanical interaction between the pivoting trigger lever and the contact part.

Claims (11)

1. Protection switch for electrical installation, comprising in an insulating box: - at least one fixed contact and one mobile contact cooperating and forming an interruptible current path in response: . either on the actuation of a magnetic and / or thermal organ for automatic triggering, . either the actuation of a manual triggering and resetting control member, - a lock comprising: . a hook movable by the automatic triggering member, . a trigger lever provided at one end with a spoiler cooperating with the hook and connected to the manual control member, so as to pivot, either by bearing on the hook to effect voluntary opening of the contacts, or on a movable axis connected to the manual control member for automatic triggering,
characterized in that the trigger lever (18) is connected to a separate contact piece (32) by means of a spring (R) constituting, on the one hand, an elastic transmission link between the lever and the piece on the other hand, contributing to the abrupt opening of the contact piece. 2. Protection switch according to claim 1,
characterized by the fact that the elastic link (R) constitutes the sole means of opening the contact piece (32). 3. Protection switch according to one of claims 1 and 2,
characterized in that the contact-carrying part (32) is pivotally mounted on a pin (30a) fixed relative to the housing, the elastic link (R) cooperating with at least one support provided on the contact part to maintain it ci applied to the fixed pin. 4. Protection switch according to claim 3,
characterized in that the pin (30a) belongs to a rigid conductive part (30) secured to a terminal (Bl) of the switch. 5. Protection switch according to one of claims 1 to 4,
characterized by the fact that the elastic link (R) cooperates, on the one hand, with an opening support (36) and, on the other hand, with a closing support (31), the supports (31, 36) being provided on the contact piece (32) and located on either side of the pivot pin (30a) of said piece. 6. Protection switch according to claim 5,
characterized by the fact that the elastic link (R) constitutes the means of pressing the movable contact (Cl) on the fixed contact (C2). 7. Protection switch according to one of claims 5 and 6,
characterized in that the elastic link (R) is a V-shaped pin spring having a first branch of the V (28) applied to a second end (24) of the release lever (18) and a second branch of the V (29 ) applicable on the closing (31) and opening (36) supports of the contact part (32). 8. Protection switch for electrical installation, comprising in an insulating box: - at least one fixed contact and one mobile contact cooperating and forming an interruptible current path in response: . either on the actuation of a magnetic and / or thermal organ for automatic triggering, . either the actuation of a manual triggering and resetting control member, - a lock comprising: . a hook movable by the automatic triggering member, . a trigger lever provided at one end with a spoiler cooperating with the hook and connected to the manual control member, so as to pivot, either by bearing on the hook to effect voluntary opening of the contacts, or on a movable axis connected to the manual control member for automatic triggering,
characterized by the fact that the hook (12) is interposed between a core (14) of the magnetic trip device (DM) and a bimetallic strip (17) of the thermal trip device (DT) and is arranged so that the start of deflection of the bimetallic strip ( 17) causes a slight plunge of the core via the pivoting of the hook. 9. Switch according to claim 8,
characterized in that the trigger lever (18) is connected to a contact piece (32) by means of an elastic link (R). 10. Protection switch according to claim 8,
characterized in that the magnetic trip device (DM) comprises a spring (35) for returning the magnetic core (15), this spring constituting a means for returning the hook (12). 11. Protection switch according to one of claims 8 to 10,
characterized by the fact that the hook has a finger (16) intended to cooperate with the bimetallic strip (17), the finger (16) carrying marks (16a) for assistance in adjusting the bimetallic strip.

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