EP0140761B1 - Operating mechanism for a low-voltage multi-pole circuit breaker - Google Patents

Abstract

This invention relates to a circuit breaker operating mechanism. The base (70) of the handle (52) moves along grooves or edges (78, 80) on the fixed guiding part formed by the mechanism support plates (40, 42). The grooves (78, 80) determine the trajectory and the fictitious pivoting axis of the handle (52) accurately. Rollers (74, 76) are fitted between the base (70) and the grooves (78, 80) to reduce the friction forces. The switch bar (28) comprises a projection located close to each electrical auxiliary so as to give a remote indication of the state of the circuit breaker and to cause automatic resetting of the auxiliary releases following tripping.

Description

The invention. relates to a control mechanism of a multipole circuit breaker with molded insulating housing, according to the preamble of claim 1.

In the majority of low voltage circuit breakers of the prior art (see FR-A-2 262 859), the handle is supported by a metal cradle or bracket in the shape of an inverted U, pivotally mounted on a fixed axis subject to the plates of the mechanism. The trajectory of the joystick has a small pivot radius due to the presence of the material axis of the cradle inside the housing. The switching bar and / or the trigger bar are generally arranged outside the trajectory of the lever.

This results in an increase in the size of the insulating housing.

The presence of this articulated cradle also increases the friction of the moving assembly requiring significant efforts to actuate the lever.

Document US-A-2 806 103 relates to a single-pole circuit breaker with molded insulating housing, formed by the assembly of a base and a cover. The lever of the mechanism comprises an internal base laterally equipped with two guide pins, capable of sliding in conjugate notches, formed in the base and the cover of the housing. The curved shape of the housing notches determines the pivot radius of the handle when it moves between the open and closed positions. Such a mechanism is perfectly suitable for a low-caliber single-pole circuit breaker with a non-removable housing, but is not suitable for a multi-pole circuit breaker whose single removable housing contains different compartments juxtaposed for housing the poles.

The object of the invention is to provide a control mechanism for a multipole circuit breaker, housed in the compact insulating housing having no influence on the movement of the handle and allowing a reduction in the friction of the moving parts of the mobile equipment.

The support member of the base of the lever comprises a guide ramp secured to each plate of the mechanism, said ramp having a profile, either curvilinear or inclined in the case of a pivoting movement of the lever with pivoting axis fictitious, or rectilinear parallel to the bottom of the case in the case of a sliding movement of the lever.

In the mechanism according to the invention, rolling members can be interposed between the underside of the base and the plates to minimize the friction forces generated during movement of the lever on the corresponding ramps. The ramps can be shaped on the upper edges of the plates, each rolling member being formed by a roller having an axial length slightly greater than the transverse spacing formed between the plates.

The absence of an additional articulated support part for the lever makes it possible to minimize the friction of the movable members of the mechanism. The fictitious axis of rotation of the lever can be located outside the housing, which makes it possible to increase the pivoting radius of the lever. This radius is perfectly defined by the dimensional characteristics of the ramps. It follows that the opposite ends of the base of the lever respectively cover the switching rod and the trip bar when the lever is in the extreme positions of the pivoting stroke. The size of the circuit breaker box is thus reduced to a minimum.

The pivot pin of the toggle rests on a cam of the release lever. This results in a variation of the opening stroke of the contact arms due to a different rotation of the bar occurring during manual opening or during opening by automatic triggering. The stroke of the contact arms is greater in the event of a trip.

Advantageously, this variation of the opening stroke is used to actuate, by means of the bar, the various electrical auxiliaries arranged on either side of the mechanism.

• la figure 1 est une vue schématique en coupe d'un disjoncteur équipé d'un mécanisme selon l'invention, l'ensemble étant représenté en position F de fermeture ;
• les figures 2 et 3 sont des vues analogues à celles de la figure 1, respectivement en position O d'ouverture manuelle et en position O/D d'ouverture par déclenchement automatique sur défaut ;
• la figure 4 est une coupe partielle du mécanisme selon la ligne IV-IV de la figure 3 ;
• la figure 5 montre une vue simplifiée à échelle agrandie de la figure 1, seules la manette et les platines du mécanisme étant représentées ;
• la figure 6 est une vue en coupe de la genouillère accouplée au barreau ;
• la figure 7 est une vue en perspective de la genouillère selon la figure 6 ;
• la figure 8 représente une variante de réalisation de la genouillère, montrée en position désaccouplée ;
• la figure 9 est une coupe selon la ligne IX-IX de la figure 8, en position montée de la genouillère ;
• la figure 10 montre une vue partielle éclatée de la figure 3, représentant un système de contacts auxiliaires SD de signalisation à distance d'un défaut ;
• la figure 11 est une vue analogue à celle de la figure 10, représentant un déclencheur auxiliaire MN ou MX du mécanisme ;
• la figure 12 est une vue schématique en plan du disjoncteur selon la fig. 10 ou 11, le couvercle étant enlevé.

Other advantages and characteristics will emerge more clearly from the description which follows of different embodiments of the invention given by way of nonlimiting examples and represented in the appended drawings in which:

• Figure 1 is a schematic sectional view of a circuit breaker equipped with a mechanism according to the invention, the assembly being shown in the closed position F;
• Figures 2 and 3 are views similar to those of Figure 1, respectively in position O manual opening and in position O / D opening by automatic triggering on fault;
• Figure 4 is a partial section of the mechanism according to line IV-IV of Figure 3;
• Figure 5 shows a simplified view on an enlarged scale of Figure 1, only the lever and the plates of the mechanism being shown;
• Figure 6 is a sectional view of the toggle coupled to the bar;
• Figure 7 is a perspective view of the toggle joint according to Figure 6;
• FIG. 8 represents an alternative embodiment of the toggle joint, shown in the uncoupled position;
• Figure 9 is a section along line IX-IX of Figure 8, in the mounted position of the toggle;
• FIG. 10 shows a partial exploded view of FIG. 3, showing a system of auxiliary contacts SD for remote signaling of a fault;
• Figure 11 is a view similar to that of Figure 10, showing an auxiliary trigger MN or MX of the mechanism;
• FIG. 12 is a schematic plan view of the circuit breaker according to FIG. 10 or 11, the cover being removed.

In FIGS. 1 to 3, a low-voltage three-pole circuit breaker comprises a box 10, parallelepipedal in molded insulating material containing an operating mechanism, designated by the general reference 12. The three poles are housed in juxtaposed compartments located in the lower part of the housing 10 and the mechanism 12 is arranged above the central pole in the upper part of the housing 10.

Each pole includes a pair of separable contacts 14, 16, an arc extinguishing chamber 18 and a thermomagnetic trip device 20. The fixed contact 14 is carried by an end conductor 22 extended externally by a first contact pad 24 making projection from the side face 25 of the housing 10. The movable contact 16 is arranged at the end of a vertical contact arm 26 secured by a spring 27 to a switching bar 28 common to the three poles. The insulating bar 28 for supporting the contact arms 26 is mounted with limited rotation between the open and closed positions of the circuit breaker and extends transversely above the poles in the upper part of the housing 10 in a direction perpendicular to the arms 26 mobile contacts. The arc extinguishing chamber 18 is constituted by a stack of metal separators or deionization sheets 30 extending perpendicular to the bottom 32 of the housing 10.

The second contact pad 34 of each pole leaves the opposite side face 36 of the housing 10, and is electrically connected to the thermomagnetic trip device 20, the latter being arranged between the arc extinguishing chamber 18 and the side face 36. The electrical connection of the contact arm 26 with the second contact pad 34 is effected by means of a flexible conductor formed by a braid 38, surrounded by an insulating sheath, not shown.

The insulation of the braid 38 constitutes a functional insulation of the mechanism 12 with respect to the active parts of each pole.

The mechanism 12 is mounted above the central pole, between two spaced plates 40, 42 extending parallel in the longitudinal direction of alignment of the contact pads 24, 34. The switching bar 28 is actuated by means of a knee lever 44 comprising a lower link 46 and an upper link 48 articulated on a pivot axis 50. The knee switch 44 cooperates on the one hand with a lever 52 for manual control projecting from an opening 53 of the cover 54, and d on the other hand with an automatic hook or trigger lever 56 pivotally mounted on a pivot 58. The lower link 46 is mechanically coupled to the switching bar 28 and the upper link 48 is articulated on an axis 60 of the trigger lever 56. The mechanical connection between the toggle joint 44 and the lever 52 takes place in an elastic manner by means of a tension spring 62, one of the ends of which is anchored to the pivot axis 50 of the knee llère 44 and the other end of which is attached to a lug secured to the lever 52.

Opposite the pivot 58, the trigger lever 56 comprises a hooking nose 64 cooperating in the armed position with a lock 66 of a trigger bar 68 made of insulating material, common to the three poles. The trigger bar 68 extends above the magnetothermal trigger 20 of each pole in a direction parallel to the switching bar 28, and is mounted with limited rotation between an armed position for locking the hooking nose 64 of the lever 56 by the lock 66 and a triggered position releasing the lever 56 by unlocking the lock 66. The passage from the armed position to the triggered position of the rotary bar 68 operates clockwise and is controlled either by the magnetothermal trigger 20 in the presence an overload or short-circuit current, either by an auxiliary trip device, in particular an undervoltage relay so as to cause the automatic triggering of the mechanism 12 and the opening of the contacts 14, 16 of the three poles by rotation of the bar switch 28 counterclockwise. The latch 66 of the trigger bar 68 is biased in the armed position by a return spring (not shown).

The lever 52 is provided with an elongated base 70 located inside the housing 10 between the mechanism 12 and the cover 54. The curved underside 72 of the base 70 is supported on a fixed guide member 73 formed by the upper edges of the two plates 40, 42 of the mechanism 12 with the interposition of two rollers 74, 76 (see fig. 4 and 5). Each plate 40, 42 is equipped with two curved or inclined ramps 78, 80 on which the rollers 74, 76 roll during the movement of the lever 52. The dimensional characteristics of the ramps 78, 80 allow. attempt to determine with precision the radius of the stroke and the pivot point M of the lever 52, the point M being the trace of a fictitious axis of rotation located in FIG. 5 in the vicinity of the bottom 32 of the housing 10, at the 'intersection of two radii XX', YY 'passing through a point on the ramps 78, 80. The position of the pivot point M of the lever 52 depends on the radius of curvature of the ramps 78, 80, and the end stops 82 , 84 delimit each ramp 78, 80 to control the extreme positions of the pivoting stroke of the lever 52. The presence of the rollers 74, 76 reduces the frictional forces generated during the movement of the lever 52, each roller 74, 76 having an axial length slightly greater than the transverse spacing d formed between the plates 40, 42 (FIG. 4).

The non-material point M of pivoting of the lever 52 may be outside the housing 10, which makes it possible to minimize the height of the housing 10 between the bottom 32 and the cover 54.

According to a variant, the ramps 78, 80 of the upper edges of the plates 40, 42 are rectilinear, extending parallel to the bottom 32 of the housing. The base 70 is also rectilinear and cooperates with the ramps to impose a translation movement limited to the handle 52 during its travel between the open and closed positions.

In FIGS. 6 and 7, the lower link 46 of the toggle joint 44 of the mechanism 12 is formed by a rectangular open loop of steel wire of circular section. The ends 88 of the open branch 90 of the loop are engaged in an opening 92 of the switching bar 28. The opposite branch 94 of the lower link 46 is positioned in a semi-open notch 96 formed in a U-shaped stirrup 98 constituting the upper link 48. The spring 62 for triggering the mechanism 12 is hooked between the branch 94 and the lever 52 and maintains the branch 94 at the bottom of the notch 96, so as to form the pivot axis 50 of the toggle joint 44.

Figures 8 and 9 show another embodiment of the toggle 44 in which each link 46, 48 is shaped into a U from a steel wire of circular section. One of the 100 lateral branches of the lower link 46 is held by the tension spring 62 in a crescentally deformed part 102 of the upper link 48.

It is noted, in Figures 1 to 4, that the opposite ends of the base 70 respectively cover the switching bar 28 and the trigger bar 68 when the lever 52 is in the extreme positions of the pivoting stroke. This results in a space saving of the housing 10 in the longitudinal direction of the poles.

The pivot axis 50 of the toggle joint 44 moves along a cam 104 of the curved lower edge of the trigger lever 56, said edge being arranged between the pivot 58 and the hooking nose 64 opposite the axis 60 of articulation of the upper link 48. The cam 104 of the lever 56 is delimited by two notches 106, 108 serving as stops for the axis 50 of the toggle joint 44 when the contacts 14, 16 of the poles are respectively in the position of closing and opening.

The operation of the mechanism 12 according to FIGS. 1 to 5 is as follows:

• position F de fermeture des contacts du disjoncteur,
• position O/D d'ouverture des contacts suite à un déclenchement automatique sur défaut,
• position P m 0 non stable correspondant au point mort d'ouverture du mécanisme 12,
• position O d'ouverture manuelle des contacts,
• position R de réarmement du mécanisme 12.

FIG. 5 schematically indicates the different positions occupied by the pivoting lever 52 during a manual control or an automatic triggering on fault of the mechanism 12:

• position F for closing the circuit breaker contacts,
• O / D position for opening the contacts following an automatic trip on fault,
• non-stable position P m 0 corresponding to the opening neutral position of the mechanism 12,
• position O of manual opening of the contacts,
• reset position R of the mechanism 12.

In the closed position F (FIG. 1), the trigger lever 56 is locked in the armed position by the lock 66, and the axis 50 of the toggle joint 44 is positioned in the first notch 106 of the cam 104.

During the manual opening of the circuit breaker (Figure 2), intervening by actuation of the handle 52 from position F to position 0, the trip lever 56 remains stationary in the armed position, and the axis 50 of the toggle moves along the cam 104 until it comes into abutment with the second notch 108. The blocking of the toggle joint 44 by the trigger lever 56 prevents the continued rotation of the bar 28 and of the contact arms 26 in the opposite direction clockwise.

Following a trip on fault, unlocking the lock 66 by the trip bar 68 releases the hooking nose 64 of the trip lever 56 causing the clockwise pivoting of the lever 56 around the pivot 58. The lever 52 is driven by the toggle 44 from the F position to the intermediate O / D position. The axis 50 of the toggle 44 is engaged in the second notch 108 of the cam 104, and the toggle 44 follows the movement of the trigger lever 56 (Figure 3) to the disarmed position. It follows that the opening stroke of the contact arms 26 following a tripping is greater than that occurring during manual opening. This increase in the stroke of the bar 28 and of the contact arms 26 (FIG. 3) in the event of tripping on a fault makes it possible to improve the breaking capacity of the circuit breaker.

The circuit breaker is reset by manual movement of the handle 52 clockwise from the O / D position to the R position of the reset close to the 0 position so as to ensure that the trip lever is hooked 56 to the lock 66. The closing of the contacts of the circuit breaker (FIG. 1) then takes place by a reverse rotation of the handle 52 actuated manually towards the position F.

• un premier système de contacts inverseurs OF de signalisation à distance des positions F de fermeture et 0 d'ouverture manuelle du disjoncteur ;
• un deuxième système de contacts auxiliaires SD de signalisation d'un défaut suite à un déclenchement automatique du mécanisme 12.

Electrical control and signaling auxiliaries are arranged on either side of the mechanism 12 in the upper part of the housing 10. The signaling auxiliaries are responsible for remotely indicating the state of the circuit breaker and include:

• a first system of reversing contacts OF for remote signaling of the closing F and manual opening 0 positions of the circuit breaker;
• a second system of auxiliary contacts SD for signaling a fault following an automatic triggering of the mechanism 12.

The control auxiliaries are formed by auxiliary triggers, in particular of the voltmetric type with undervoltage MN and / or with current emission MX intended to cause the unlocking of the lock 66 to trigger the. mechanism 12 following the absence of tension on the network or to a remote control opening the circuit breaker. The variation of the opening stroke of the contact arms 26 intervening by a different rotation of the bar 28, according to the type of manual or automatic control on fault, is advantageously used to actuate the various electrical auxiliaries. The switching bar 28 for this purpose comprises a projection 110 (Figures 10 and 11) or boss arranged in the vicinity of each auxiliary.

In FIG. 10, the projection 110 of the bar 28 cooperates in the O / D position of the lever 52 with a transmission lever 112 intended to actuate the reversing contact 114 of the second system of contacts SD for remote signaling of a trip on fault. .

Similarly, the projection 110 associated with the first auxiliary contact system OF (not shown) would actuate the corresponding change-over contact 114 if the lever 52 was in the manual opening 0 position. The change-over contact 114 of the first OF system is therefore controlled prior to that of the second SD system because of the different opening travel of the bar 28 in the direction of the arrow f.

In FIG. 11, an auxiliary release MN or MX comprises an angled control lever 116 pivotally mounted on an axis 118. One end of the control lever 116 cooperates with a protrusion 120 of the trigger bar 68, and the The opposite end is in contact with the lever. transmission 112.

When the mechanism 12 is triggered, caused by the auxiliary trigger MN or MX, the control lever 116 pivots clockwise and drives the bar 68 towards the triggered position. When the lever 52 arrives in the intermediate O / D position, the projection 110 of the bar 28 actuates the levers 112, 116 in the direction of the arrows f to ensure automatic resetting of the auxiliary release MN or MX. This automatic rearming by the bar 28 is impossible in position 0 of the lever 52.

Claims (8)

1. An operating mechanism for a multipole circuit breaker comprising a molded insulating housing (10) having a base (32) and a cover (54), said mechanism being mounted between two parallel plates (40, 42) and comprising :

a handle (52) for manual actuation of the mechanism (12) with an extended base (70) located inside the housing (10) of a support element arranged to determine the trajectory of the handle (52),

a toggle device (44) associated with an automatic trip lever (56) and with a switch bar (28) common to all the poles,

a stored energy spring (62) fitted between the handle (52) and the axis (50) of the toggle (44),

a latching device (66) of the trip lever (56) in the charged position,

a trip bar (68) which can be either in an inactive position or a tripped position to respectively latch and unlatch the trip lever (56),

and tripping means cooperating with the trip bar (68) when a fault occurs or an external order is given, characterized by the fact that the support element of the base (70) of the handle (52) comprises a guiding plane (78, 80) secured to each plate (40, 42) of the mechanism (12), said plane comprising a profile either arcuate or inclined if the handle (52) has a pivoting movement around its fictitious pivoting axis, or straight and parallel to the base (32) of the housing (10) if the handle (52) has a sliding movement.

2. An operating mechanism according to claim 1, characterized by the fact that roller elements (74, 76) are mounted between the lower face (72) of the handle base (70) and the planes (78, 80) of the plates (40, 42) to reduce the friction forces generated when the handle (52) is moving.

3. An operating mechanism according to claim 2, characterized by the fact that the planes (78, 80) are shaped on the upper edges of the plates (40, 42), each roller element (74, 76) being formed by a roller with an axial length slightly greater than the transverse clearance between the plates (40, 42).

4. An operating mechanism according to one of the claims 1 to 3, the toggle device (44) comprising a lower rod (46) coupled with the switch bar (28) and an upper rod (48) pivoting on the automatic trip lever (56), characterized by the fact that the lower rod (46) comprises a circular cross-section steel wire branch (94, 100), engaged in a notch (96, 102) in the upper rod (48), to constitute the axis (50) of the toggle (44), said branch (94, 100) being held firmly in the notch (96, 102) by the trip bar (68) hooked over the handle (52) and said branch (94, 100).

5. An operating mechanism according to one of the claims 1 to 4, comprising further :

a trip device cooperating with the trip bar (68) when a fault occurs,

a stop cooperating with the toggle (44) to ensure a variation of the opening travel of the contact arms (26) due to a different rotation of the switch bar (28) happening during the opening by tripping on fault occurrence,

and electrical control and indication auxiliaries fitted on either side of the mechanism (12) and comprising a first and a second system of auxiliary contacts (OF, SD) giving a remote indication of the state of the circuit breaker, as well as voltmeter type auxiliary releases (MN, MX), particularly undervoltage or shunt trip, characterized by the fact that the trip lever (56) has a cam (104) limited by two notches (106, 108) acting as stops for the pivot axis (50) of toggle (44), and that the switch bar (28) has a projection (110) or boss, located close to each electrical auxiliary, so as to actuate the first system of auxiliary contacts (OF) indicating manual opening before actuating the second system of auxiliary contacts (SD) indicating a fault, and/or to reset the auxiliary releases (MN, MX) automatically following tripping of the mechanism.

6. An operating mechanism according to claim 5, characterized by the fact that the notches (106, 108) of the cam (104) are located along the curved lower edge of the trip lever (56) between the pivot pin (58) and the latching nose (64) of the lever (56).

7. An operating mechanism according to claim 5 or 6, characterized by the fact that a transmission lever (112) is fitted between the projection (110) of the switch bar (28) and the corresponding electrical auxiliary (OF, SD, MN. MX).

8. An operating mechanism according to one of the claims 1 to 7, characterized by the fact that the opposite ends of the base (70) of the handle (52) cover respectively the switch bar (28) and the trip bar (68) when the handle (52) is in its end of travel positions.

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