EP0847105B1 - Wire connecting terminal in a modular electrical device - Google Patents

Description

The present invention relates to a housing of an apparatus electric modular type, formed by two half-shells assembled, or resulting from a cover / base assembly, comprising at least one connection terminal to a conductor arranged in a housing provided in said housing to accommodate said terminal. A such a connection terminal includes a cage housing a contact plate cooperating with a screw provided for bringing together or separate said plate from one of the walls of the cage, in order to fix by clamping or releasing by loosening said conductor.

This type of terminal is well known, disclosed for example in the document DE-A-3 417 010 applied to a connection box to multiple entry. In this case, the rotary movement of the screw is transformed in a classic way into a movement of translation of the cage in its housing, aimed at spreading or bring said cage closer to the stationary contact plate.

Modular electrical devices concerned by the invention generally have an even number of terminals used to connect to circuits in which they perform a function particular. These are, for example, circuit breakers, auxiliaries circuit breakers, contactors, etc.

The problem posed and resolved by the present invention relates to the maintenance of the cages in the housings. When an operator tightens or loosens a connection by screwing or unscrewing the screw corresponding, the effort is transmitted to the cage via said screw. However, the cages are in most cases arranged floating at inside the housing provided in the boxes to accommodate them. Said housings being made up of two half-shells, the housings are distributed in these half-shells, divided into two half-housings located opposite, separated by the separation plan of the half-shells.

When the torque exerted on the screw is transmitted to the cage, the latter repercussions on the half-shells, which tend to deviate. Indeed, the cage rotates in its housing, which is not large enough to allow this rotation without affecting the hulls. In any event, for allow a good connection to be made, it is necessary to block the cages in their housing. This is achieved by the hulls which maintain, with a fairly wide tolerance, hence the abovementioned designation of "floating cages".

This need to maintain the cages, so that there is resistance to the tightening / loosening effort is also at the heart of the problem, since it is a priori antagonistic of the need to prevent the two shells forming the housing to separate.

One solution could be to keep the cage in rotation, by means of example of rivets / bouterolles, or by a reinforced configuration of housing by adding material. These solutions are however theoretical, because the current design of the boxes, and more generally of the whole electrical equipment, aims to allow on the one hand a maximum space saving incompatible with the aforementioned additions of material, and on the other hand to result in assembly automation making riveting or any other prohibitive equivalent fixation.

A solution to this problem has been disclosed in European patent EP 0 541 459 in the name of MERLIN GÉRIN. It consists in providing the cage with projections pointed diagonally to each other, and oriented substantially parallel to the plane of separation of the half-shells, in a direction as they are embedded in the walls of the housing, in each half-shell, so that by tightening the screw, we get closer said half-shells.

The housing then remains joined during the tightening operation. The rotational movement imparted to the screw is not transmitted to the cage due to its attachment to the housing and, in combination with the anchoring of the teeth in the half-shells, contributes to ensuring an effective tightening of the conductor without deformation of the insulating housing.

The object of the invention also consists in making a housing / connection terminal which does not cause deformation of the housing during of the tightening operation, but without modifying the cage.

According to the invention, it is the contact plate housed in the cage which includes means for anchoring to the two half-shells of the apparatus electric, so that the torque exerted on the screw during tightening is transmitted to said half-shells so that they tighten at the level of their junction surfaces.

So instead of exerting reaction forces parallel to the base of the housing, as was the case in document EP 0 541 459, the forces are present applied perpendicular to said base, and terminate also to bring the two half-shells closer together.

The advantage of this design is as follows: during an operation of connection of a conductor to a terminal, the first force exerted by the operator is always an axial force, immediately preceding the application of the rotary torque. Consequently, anchoring begins immediately, as soon as the application of axial thrust, which provides maximum guarantee efficiency and overcomes possible initial anchoring problems related the need to obtain reaction forces to an originally rotating torque.

After the initial anchoring, in the configuration of the invention, the torque exerted on the screw is transmitted to the half-shells so that they approach the level of their junction surfaces.

More specifically, the means for anchoring the contact plate have teeth protruding towards stops made in said half-shells, intended to become embedded in said abutments as and when the exercise of the tightening torque on the screw.

The teeth are located on the edges of said contact pad oriented opposite the head of said screw, the tip of each tooth becoming encrusted along an axis parallel to that of the screw, in the axial tightening direction of this last.

Preferably, each contact pad has at least one tooth cooperating with a surface of a stop that is substantially perpendicular in shape to the axis of the screw and located on each of the half-shells forming the housing.

More preferably, the contact plate has a central body plane with two end portions perpendicular to said body, one of which is provided with lateral fins projecting from each side of said central body, one of the teeth being located on the end edge of the portion perpendicular without fin, offset to the side, the other tooth being located on the parallel edge of the fin located on the other side with respect to the longitudinal axis of the insert, both teeth pointing in the same direction.

According to a possible variant, the contact plate has a U-shape of which the ends of the legs have lateral fins whose edges parallel oriented towards the base of the U each have a tooth, said teeth being located on either side of the longitudinal axis of said base of the U, a tooth also being located on the fin opposite the tooth.

• Les figures 1a et 1b sont des vues en perspective d'une borne de raccordement complète selon l'invention ;
• La figure 2 est une vue en coupe selon le plan de jonction des demi-coques, de ladite borne dans son logement représenté schématiquement ;
• La figure 3 est une coupe de la représentation de la figure 2, vue dans la direction des flèches III ;
• La figure 4 est également une coupe de la représentation de la figure 2, mais vue dans la direction des flèches IV ;
• La figure 5 est enfin une autre coupe de la représentation de la figure 2, vue dans la direction des flèches V ;
• La figure 6 est une vue en perspective d'une borne de raccordement selon la présente invention, dans son environnement immédiat également représenté en figure 2 ; et
• La figure 7 est une variante de la plaquette de contact vue en perspective.

Other advantages and characteristics of the present invention will emerge more clearly from the detailed description which follows, in which a particular example of the invention will be explained with reference to the appended figures, for which:

• Figures 1a and 1b are perspective views of a complete connection terminal according to the invention;
• Figure 2 is a sectional view along the junction plane of the half-shells, said terminal in its housing shown schematically;
• Figure 3 is a section of the representation of Figure 2, seen in the direction of arrows III;
• Figure 4 is also a section of the representation of Figure 2, but seen in the direction of the arrows IV;
• Figure 5 is finally another section of the representation of Figure 2, seen in the direction of the arrows V;
• Figure 6 is a perspective view of a connection terminal according to the present invention, in its immediate environment also shown in Figure 2; and
• Figure 7 is a variant of the contact plate seen in perspective.

The figures above represent a preferred example of the invention, but which cannot be considered as limiting of it. So in Figures 1a and 1b, the connection terminal comprises a cage 1 housing a contact pad 2 whose movement relative to the cage 1 is caused by a screw 3.

The teeth 4, 5 projecting from the contact pad 2 are located on either side of the cage 1, and oriented along an axis parallel to that of the screw 3, points directed in the direction of tightening thereof.

The end portions 6, 7 of the clamping plate are oriented at opposite each other and therefore have opposite end edges. This is why, one of said portions is provided with lateral fins 8, 9 offering oriented edges like the end edge of portion 6.

As will appear in the following figures, each tooth 4, 5 is embedded in the clamping in stops molded in the half-shells. To that the main function of the invention is realized, it is important that each tooth cooperates with a stopper of a half-shell, hence their location substantially symmetrical with respect to a vertical longitudinal median plane cutting the contact plate 2, giving a representation equivalent to that of figure 2.

In this figure, the terminal environment, consisting of the housing 10 mounted in the half-shells 11, 12 and the elements located in the vicinity immediate said housing 10 are also shown. For intelligence of the invention proper, however, only the geometry of the housing 10, for two main aspects.

First, on the periphery of each housing, there are stops in which the points 4, 5 are anchored. In Figures 2 and following, the stop associated with the half-shell 11 is referenced 13, while the stop of the other half-shell 12 bears the reference 14. Due to the almost anchoring contact pad 2 immediately from the start of tightening, said pad 2 is fixed, and the connection of the conductor with the terminal, obtained by the jamming of the stripped end of said conductor between plate 2 and one of the walls of the cage, can only be produced if said cage is movable in his home.

Thus, there is a sliding of the only element still endowed with a degree of freedom in the housing 10, that is to say the cage 1, as the tightening or loosening. When no conductor is connected, cage 1 is located in the vicinity of the wall of the housing 10 closest to the base of the apparatus. In the clamping position, said cage 1 is on the contrary located at proximity of the wall of the housing 10 surrounding the screw 3.

The volume of the housing 10 is provided accordingly, and allows a movement of the cage 1 compatible with the tightening requirements. In this configuration, all of the mechanical connections act as a classic motion transformer, transforming rotary motion printed on the screw 3 in a translational movement of the cage 1.

In the final tightening phase, the torque applied by the screw 3 is exerted mainly on the contact plate 2, which is immobilized due to anchoring the teeth 4, 5 in the stops 13, 14. The efforts are nevertheless passed on to the two half-shells, which tend to approach one of the other.

The two figures 3 and 4 are two opposite views from a single cutting surface. They clearly show the respective locations of teeth 4, 5 laterally with respect to the contact pad 2, so as to be locate each in a half-housing of each half-shell 11, 12.

The main interest of figure 5 is to show the relative positioning axial of the cage 1 and of the contact plate 2. In addition, the cutting plane, on the left side of the figure, go into tooth 5 which we see the exact positioning on the one hand with respect to the end portion 7, and on the other hand on the stop 14.

Figure 6 shows the elements of the previous figures 2 to 5, but in perspective. It highlights the cooperation of tooth 4 with the stop 13. It also specifies the configuration of the cage 1 / plate assembly. contact 2: cage 1 is housed in volume 10, while the portions ends 6 and 7 of the contact plate 2 are nestled outside said volume, and therefore do not hinder the travel of the cage 1 when it moves in rectilinear translation.

FIG. 7 represents a possible variant of the contact plate 2 '. The end portion 7 'is strictly identical to the portion 7 of the part described above, with two lateral fins 8 ', 9' and a tooth 5 'anchor.

On the other hand, the second end portion 6 ′ is positioned so that that it forms a U with the first. It has a 20 'notch allowing the addition of an additional tooth 21 'on a fin 22', in more than tooth 4 'identical to tooth 4 of contact pad 2 previously described.

The stops of the half-shells must of course be adapted in Consequently, as well as the recesses arranged on the periphery of the housings 10. Thus, the addition of a tooth 21 'requires for example the addition of a stop (elements not shown).

The invention and its variant, as described, are not limitative of the invention, and should only be considered as examples of application.

Claims (6)

1. Casing of an electrical device of modular type formed of two assembled half shells 11, 12, comprising at least one terminal for connection to a conductor disposed in a housing 10 provided for that purpose in said casing, said connecting terminal comprising a cage 1 housing a contact plate 2 co-operating with a screw 3 with a view to fixing said conductor by tightening or releasing it by loosening, characterised in that said contact plate 2 comprises means of anchorage 4, 5 to the two half shells 11, 12 so that the torque exerted on the screw 3 during the tightening is transmitted to said half shells 11, 12 such that they come closer together at their junction surfaces.
2. Casing of an electrical device of modular type according to claim 1, characterised in that the means of anchorage of the contact plate 2, 2' comprise teeth 4, 5 projecting towards stops 13, 14 formed in said half shells 11, 12, designed to dig into said stops 13, 14 as the tightening torque is applied to the screw 3.
3. Casing of an electrical device of modular type according to claim 2, characterised in that said teeth 4, 5 are situated on edges of said contact plate 2 oriented in the opposite direction to the head of said screw 3, the point of each tooth 4, 5 digging in along an axis parallel to that of the screw 3 in the axial tightening direction of the latter.
4. Casing of an electrical device of modular type according to claim 3, characterised in that each contact plate 2 comprises at least one tooth 4, 5 co-operating with one surface of a stop 13, 14 acting substantially perpendicular to the axis of the screw 3 situated on each of the half shells 11, 12 forming the casing.
5. Casing of an electrical device of modular type according to claim 4, characterised in that the contact plate 2 comprises a flat central body provided with two end portions 6,7 perpendicular to said body, one of which is provided with lateral lugs 8, 9 projecting on each side of said central body, one of the teeth 4 being situated on the end edge of the perpendicular portion 6 without the lug, offset towards the side, the other tooth 5 being situated on the parallel edge of the lug offset towards the side, the other tooth 5 being situated on the parallel edge of the lug 7 situated on the other side in relation to the longitudinal axis of the plate 2, the two teeth 4, 5 pointing in the same direction.
6. Casing of an electrical device of modular type according to claim 4, characterised in that the contact plate 2' has a U shape in which the end of the limbs comprises lateral lugs 8', 9', 22' the parallel edges of which, oriented towards the base of the U, each comprise a tooth 7', 21', said teeth 7', 21' being situated on either side of the longitudinal axis of said base of the U, one tooth 4' additionally being located on the lug 22' facing the tooth 21'.

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