EP0037758B1 - Electrical equipment with automatic connection, especially connector for electrical conductors - Google Patents

Description

The present invention relates generally to electrical equipment with automatic connection, that is to say electrical equipment whose connection terminals do not require the implementation of any screw. their connection to an electrical conductor is by simply plugging it, previously stripped for this purpose at its end, and it is more particularly, but not exclusively, those of these electrical devices which have no other function than ensure the connection of two or more electrical conductors, for example for the establishment of branches, and therefore constitute only simple connectors.

Such connectors have been known for a long time, in particular by English patent No. 466 821.

In general, they comprise, in a housing made of insulating material having at least one inlet passage or plug-in orifice suitable for the introduction of the conductive core of an electrical conductor, a metal part, called here for convenience, and a spring strip, which extends obliquely to the axis of said inlet passage, and which, when the conductive core of an electrical conductor is actually engaged in such an inlet passage , is suitable for applying the latter against said guide.

In practice, as regards the connection of at least two electrical conductors, at least two inlet passages are provided.

In the British patent No. 466821 mentioned above, these inlet passages are arranged on two opposite faces of the housing.

However, it is known to arrange them on the same face thereof, in particular by the English patent No. 1,272,584 and by the French patent No. 2,224,890.

To remove the box of insulating material from the effects of the spring strip used, and prevent this box from having to withstand the tightening reaction due to this spring strip, it has been proposed to constitute the guide and the strip spring in the form of a self-supporting unit, said guide being alone to absorb the effects of said spring strip, without reaction on the housing.

Such an arrangement is found in particular already in the English patent No. 466 821 mentioned above, in which some of the proposed embodiments include a guide in the form of a frame confining the associated spring strip.

It has also already been proposed to produce guides in the form of an open U, or in the form of simple bent plates.

But then the problem arises of the junction to be provided between the guide and the spring strip for constitution by the assembly of a self-supporting unit.

Most often, and this is the case in particular in French patent No. 2224890 mentioned above, the spring strip is attached by riveting to the guide, that is to say that the rivet used for this purpose constitutes an independent part, or that it is formed by a leg coming in one piece with the guide. by appropriate cutting and folding, like stapling.

In both cases, such a rivet does not fail to make a significant projection on the guide, which inevitably implies a significant increase, at least local, in the overall dimensions, perpendicular to the plugging direction.

In addition, in the case where this rivet is formed by a tab coming from the guide, its resistance over time, and therefore the elastic clamping capacities of the spring strip to which it provides support, are dependent on the specific characteristics of the material. constituting such a guide, and in particular its creep characteristics.

However, in this case, such a guide first having the function of ensuring good electrical conduction, it is usually made of copper, possibly tinned, which, as is known, is inevitably liable to flow in the time.

It is therefore not uncommon in these conditions, that the mechanical junction of the spring strip with the guide takes play over time, to the detriment of the clamping capacity of this spring strip, and therefore to the detriment of the characteristics. of the connection it must provide.

In the English patent GB-A-1 447 935, the spring strip is engaged in a slide formed between the running part of one of the wings of the guide and the legs which are punctured therefrom.

But the guide is a relatively thick piece, which is difficult and delicate to shape with precision.

If its shaping is not exact, the holding of the spring leaf is not properly ensured.

In any event, the establishment of this spring strip involving engagement in a slide, it can be difficult to ensure.

The present invention generally relates to an electrical apparatus with automatic connection, and in particular a connector for electrical conductors, free of such drawbacks, and also having other advantages.

This electrical equipment is of the type comprising, in an insulating material housing having at least one inlet passage suitable for the introduction of the conductive core of an electrical conductor, a metal U-shaped piece, known as a guide, and a strip of spring, which extends obliquely to the axis of said inlet passage, between the wings of said guide, and which, when that the conductive core of an electrical conductor is engaged in such an inlet passage, is suitable for applying said conductive core against one of said wings of said guide, and is characterized in that, by a fold, said strip of spring is fitted onto the other wing of the guide so that it bears both on the internal face of said wing and on the external face of the latter.

Thus, the mechanical subjugation of the elastic strip to the guide for constituting a self-supporting unit is in no way dependent on the specific qualities of the material constituting this guide, which is advantageously a guarantee of permanence of the electrical characteristics of the together in time.

Preferably, between the wings of the guide, the fold of the spring strip forms a spring loop, so that, on the internal side of the guide, the spring strip bears by an elbow on the concerned wing of the latter. , while, on the external side of said guide, it bears on this wing by a flat part.

Such a spring loop has a double advantage.

First of all, when, an electrical conductor being plugged in by its conductive core between the spring strip and the guide, a tearing pull is exerted from the outside on this electrical conductor, it contributes to ensuring a bracing of the spring strip between the two wings of the guide effectively and energetically opposing the disengagement of said electrical conductor.

In addition, by its own elasticity, it contributes to an adaptation of the elastic characteristics of the spring strip to the dimensional characteristics of the conductive core to be retained, its torsional elasticity advantageously combining for this purpose with the elasticity of bending of the spring leaf.

Furthermore, thanks to the interlocking of the spring strip on the guide by a simple folding of this spring strip, according to the invention, the mechanical securing thus obtained of this spring strip to this guide does not translate, to the outside of said guide, only by a slight projection, so that the overall dimensions of the assembly perpendicular to the direction of insertion is advantageously reduced.

In practice, this projection is reduced to the thickness of the spring strip, even when, in order to prevent it from escaping from the guide by a progressive path, there is provided a projection on the latter with which, for its retention, said spring strip is engaged by a recess.

Finally, the fitting according to the invention of the spring strip on the guide for the subjection to this of this spring strip constitutes only a relatively simple and economical mounting operation to be carried out, in particular compared to the operations riveting or stapling usually covered so far for such securing.

Furthermore, for cooperation with the conductive core of an electrical conductor, a tongue is preferably cut out at the free end of the spring strip, said tongue being folded back in the direction of the wing of the guide against which must be applied. such a conductive soul.

This results in a double advantage.

First of all, this tongue, which constitutes the active part of the spring strip, that is to say the part of this strip which ensures the effective retention of the conductive core of the conductor concerned by applying it against the guide, forms, with this guide, an angle more acute than that of the current part of the spring strip and, therefore, it is capable of better anchoring in said conductive core.

In addition, the active edge of this tongue is, during assembly, protected from any contact with the guide, because, with respect to the latter, it is set back relative to the current part of the strip spring, so that it is only the latter which bears on said guide.

The active edge of the tongue of the spring strip is thus spared from any matting, and, which is favorable to the retaining function which it must assume, it retains all its integrity and all its cutting edge.

In addition, there is, longitudinally, a shift between the active edge of the tongue of the spring strip and the remaining part of the corresponding edge of this spring strip, so that if, in the absence of conductor, the latter, which then relates to the guide, comes to injure the latter, such an injury has no effect on the quality of the electrical contact then obtained between the conductive core of a conductor and the guide, the contact pressure between this conductive core and this guide taking place, under the stress of the tongue of the spring strip, at a location different from that at which such a wound may possibly be found.

In practice, in the case of a connector, and in a manner known per se, several spring strips are provided side by side, and these various spring strips belong to the same part, being cut by slots therein. .

However, preferably, the slots thus separating two by two these spring lamellae have disjoint edges.

In other words, these are not slots obtained by simple shearing, but slots obtained by cutting with the press.

This results in real freedom of movement of the spring lamellae with respect to each other, both in one direction and in the other, which is not the case when the slots separating two by two these lamellae spring are obtained by a simple shear, such slots then having, in the thickness of the lamellae, an irregular cut, that is to say, not planar, not allowing in practice a free movement of these lamellae by compared to others only in a sense.

Thanks to the slots with separate edges thus preferably implemented, the spring lamellae are completely independent from each other, so that the clamping pressure developed by any of them on the conductive core of a conductor is in no way conditioned by the state, clamping or freedom, of others.

In practice, and in a manner known per se, in the case of a connector, for which the housing has on the same face at least two inlet passages, each suitable for the introduction of the conductive core of an electrical conductor , the middle part of the guide has an opening to the right of each of these inlet passages, for passage of such a conductive core.

However, according to the apparatus described, said middle part of the guide extends beyond the spring lamellae relative to the inlet passages, the concavity of this guide being directed towards them.

It follows that each conductor, and therefore its conductive core, are advantageously guided on either side of the electrical contact zone due to the corresponding spring strip, namely, by the inlet passage of the housing, d 'a first side of this contact area, and through the opening of the guide, on the other side of it.

There is thus optimal stability of the electrical contact zone, which, being an electrical contact being made under relatively low pressure, is favorable for obtaining a good connection, any possible displacement of this zone. contact contact advantageously avoided.

Finally, in the case of a connector, and in a manner known per se, the housing is preferably formed of a hollow body in a thermowell, and of a closure wall attached to said body.

However, according to the apparatus described, the inlet passages of said housing are preferably formed in said closure wall thereof.

This advantageously results in the hollow body of the housing being relatively simple to mold, its molding not requiring the use of any drawer.

• la figure 1 est une vue en perspective d'un appareillage électrique à connexion automatique suivant l'invention ;
• la figure 2 est, à échelle supérieure, une vue longitudinale en coupe de cet appareillage, suivant la ligne 11-11 de la figure 1 ;
• la figure 3 est une vue en perspective du seul guide que comporte cet appareillage, représenté isolément ;
• la figure 4 est une vue en coupe longitudinale de ce guide, suivant la ligne IV-IV de la figure 3 ;
• la figure 5 en est une vue en élévation, suivant la flèche V de la figure 4 ;
• la figure 6 en est, à échelle supérieure, une vue partielle en coupe transversale, suivant la ligne VI-VI de la figure 4 ;
• la figure 7 est une vue en perspective de la seule pièce rassemblant les diverses lamelles de ressort que comporte l'appareillage électrique concerné, vue isolément ;
• la figure 8 est une vue en plan de cette pièce, suivant la flèche Vili de la figure 7 ;
• la figure 9 est une vue analogue à celle de la figure 2, lorsqu'au moins un conducteur électrique est enfiché dans l'appareillage électrique concerné.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which:

• Figure 1 is a perspective view of an electrical apparatus with automatic connection according to the invention;
• Figure 2 is, on a larger scale, a longitudinal sectional view of this apparatus, along line 11-11 of Figure 1;
• Figure 3 is a perspective view of the single guide that includes this equipment, shown in isolation;
• Figure 4 is a longitudinal sectional view of this guide, along the line IV-IV of Figure 3;
• Figure 5 is an elevational view, along arrow V of Figure 4;
• Figure 6 is a larger scale, a partial view in cross section along the line VI-VI of Figure 4;
• Figure 7 is a perspective view of the single piece of the various spring strips that includes the electrical equipment concerned, seen in isolation;
• Figure 8 is a plan view of this part, along the arrow Vili of Figure 7;
• Figure 9 is a view similar to that of Figure 2, when at least one electrical conductor is plugged into the electrical equipment concerned.

These figures illustrate the application of the invention to the constitution of a connector with automatic connection 10, suitable for ensuring the junction between them of two or more electrical conductors 11 after stripping the end of the conductive core 12 from those -this.

In general, such a connector 10 comprises a case of insulating material 13 having, side by side, on the same face, at least two inlet passages 14 each suitable for the introduction of the conductive core 12 of an electrical conductor 11.

In the embodiment shown, there are three of these inlet passages 14, but it goes without saying that such a number is in no way limiting on the present invention.

In practice, the housing 13 is formed of a hollow body 15, in a flattened glove finger, and of a transverse closing wall 16, attached to said body 15, at the outlet of the latter.

On its opposite main faces, the hollow body 15 has outward depressions 18 adapted to facilitate gripping, FIGS. 1 and 2.

At its end opposite to the closure wall 16, the housing 13 also has an opening 19 suitable, in the usual manner, for tension checks.

In the embodiment shown, the closure wall 16 comprises transversely a shoulder 20 by which it bears against a complementary shoulder 21 of the housing 13, and it is secured to this housing by welding, bonding, snap-fastening or the like.

In the case of welding or bonding, this can for example occur in the plane of the shoulders 20, 21, or perpendicular to them.

Each inlet passage 14 is formed of two successive sections, namely, a first section of greater diameter 22, suitable for full-diameter penetration of a conductor 11, and a second section of smaller diameter 23, suitable only for penetration of the conductive core 12 of such a conductor 11.

In the housing 13 thus formed is arranged a metal U-shaped piece 25, said guide.

This guide 25 is for example made of tinned copper.

It has two wings 26, 27, which extend parallel to the main walls of the hollow body 15, between two internal shoulders 28, 29 thereof, and a middle part 30, which extends transversely, in contact with the wall background 31 of the hollow body 15, at the end of this hollow body opposite the closure wall 16.

The concavity of the guide 25 is therefore directed towards the inlet passages 14.

In line with each entry passage 14, the middle part 30 of the guide 25 has an opening 33.

There are therefore three openings 33 in the guide 25 in the embodiment shown, and, in line with these openings 33, the bottom wall 31 of the hollow body 15 is affected by a recess 34.

In the axis of each inlet passage 14 of the housing 13, the wing 26 of the guide 25 has, on its internal face, a groove 35.

In the embodiment shown, and as is better visible in Figure 6, such a groove 35 has transversely a trapezoidal section.

On the outer face of the wing 27 of the guide 25 protrudes, along each of the longitudinal edges of this wing, in the vicinity of its transverse edge, a lug 37.

In the embodiment shown, such a lug 37, which is integral with the guide 25, is formed by a tongue, which is cut in the wing 27 concerned of this guide and protrudes on this wing away from the edge transverse free thereof, and whose end is provided with a spoiler 39, by striking for example.

In the embodiment shown, the wing 27 of the guide 25 thus formed is substantially longer than the wing 26 of the latter, but it is obviously not necessarily so.

For each inlet passage 14 of the housing 13, there is provided therein a spring strip 40 which extends obliquely relative to the axis of said inlet passage, between the wings 26 and 27 of the guide 25, and which, when the conductive core 12 of an electrical conductor 11 is engaged in such an inlet passage 14, is suitable for applying said conductive core 12 against said wing 26 of the guide 25, as will appear below.

In the embodiment shown, there are therefore three spring blades 40.

In practice, and in a manner known per se, they belong jointly to the same part 41, by being cut by slots 42 therein.

The slots 42 thus separating the spring leaves 40 in pairs are with disjointed edges; in other words, the edges or lips of such a slot 42 are at a distance from each other.

According to the invention, each spring strip 40 is simply fitted by a fold 43 on the wing 27 of the guide 25.

In the exemplary embodiment shown, such a fold 43 is obviously common to all of the spring lamellae 40, belonging to the part 41 from which these are derived.

Preferably, and as shown, this fold 43 forms, between the wings 26, 27 of the guide 25, a spring loop 44.

Thus, on the internal face of the wing 27 of the guide 25, the fold 43 common to the spring strips 40 is supported on this wing 27 by an elbow 45.

By cons, on the outer face of this wing 27, such a fold 43 is supported by a flat part 47, which in practice forms the end.

In the embodiment shown, this flat part 47 has two recesses by which said fold 43 is engaged with the lugs 37 provided for this purpose projecting from the wing 27 concerned of the guide 25 on which it is engaged.

It should be emphasized that, thanks to such mounting by simple interlocking, the transverse size of the connector 10 according to the invention is essentially conditioned by the spacing between the wings 26, 27 of the guide 25 which it contains, the projection on the wing 27 of this guide due to the subjection to the latter of the spring lamellae 40 being reduced in practice to the mere thickness of these.

For cooperation with the conductive core 12 of an electrical conductor 11, a tongue 50 is, according to the invention, cut out; for example by stamping, at the free end of each spring strip 40, FIGS. 1 and 8.

Such a tongue 50 is folded in the direction of the wing 26 of the guide 25.

Its angle of incidence 11 relative to this wing 26 is therefore greater than that 12 of the current part of the spring strip 40 from which it is detached; figure 2.

This angle of incidence 11 is for example of the order of 30 to 35 ° for the rest position of such a spring strip 40.

As it should be emphasized, the active edge of such a tongue 50, which itself constitutes the active part of the spring strip 40 from which it is detached, is offset longitudinally relative to the corresponding edge of the running part of this spring strip 40, and is therefore set back relative to the latter; therefore, only the edge of the current part of the spring strip 40 bears against the wing 26 of the guide 25 for the rest configuration shown in FIG. 2.

When, after stripping the end of its conductive core 12, an electrical conductor 11 is plugged into the connector 10 according to the invention, through one of the inlet passages 14 of the housing 13 thereof, said conductive core 12 resiliently drives the spring strip 40 associated with this inlet passage 14, FIG. 9.

Such a spring strip 40 then presses the conductive core 12 against the wing 26 of the guide 25, the corresponding elasticity being due both to its own flexural elasticity and to the torsional elasticity of the loop 44 of the fold 43 which extends it.

Under the corresponding elastic force, the tongue 50 of the spring strip 40 is anchored in the conductive core 12, and therefore opposes any release thereof by simple traction.

Indeed, if, for the purposes of such a clearance, a traction is exerted on the conductor 11, the spring leaf 4Q arches between, on the one hand, the tongue 50, which, by means of the conductive core 12 of the conductor 11, bears on the wing 26 of the guide 25, and, on the other hand, the elbow 45 of the fold 43 which extends it, which takes support on the other wing 27 of this guide 25; it therefore finally bows between said wings 26, 27 of the guide 25.

In practice, the removal of the electrical conductor 11, which remains possible, can only be done by the combination of alternating rotation of the connector 10 associated with traction of the electrical conductor 11; such a withdrawal cannot therefore be fortuitous.

As already mentioned above, it should be noted that, given the location of the guide 25 in the housing 13, the middle part 30 of this guide 25 extends beyond the spring strip 40 relative to the corresponding inlet passage 14, so that the conductive core 12 of the conductor 11 concerned is suitably guided on either side of the contact zone provided by this spring strip, namely, by the inlet passage 14 on a first side of this contact zone, and through the corresponding opening 33 of the guide 25, on the other side of the latter.

It should also be emphasized that the conductive core 12 of the conductor 11 is also suitably positioned by its engagement in the corresponding groove 35 of the wing 26 of the guide 25 in contact with which it is located.

From an electrical conductor 11 thus plugged into the connector 10 to the other, the electrical connection is essentially made by the guide 25, the spring lamellae 40 however participating in this electrical connection when, as is usual, the part 41 to which they belong is a metal part.

In practice, it is a part formed from a spring steel blank suitably cut and folded.

Finally, as is easy to understand, although the fitting according to the invention of this part 41 on the wing 27 of the guide 25 is sufficient to ensure the subjection of the latter to this guide, in particular during the mounting of the assembly, the pins 37 provided projecting from this guide 25 making it possible to avoid that, under the stresses due to repeated withdrawals of electrical conductors 11 as described above, such a part 41 does not come inadvertently, by progressive path, more or less partially escape the guide 25.

Of course, the present invention is not limited to the embodiment described and shown, in particular as regards the number of electrical conductors 11 capable of being inserted in the connector more particularly described.

In addition, the field of application of the invention is not limited to that of such connectors, but extends to that of any electrical apparatus comprising a terminal suitable for the connection of an electrical conductor.

It goes without saying that, in this case, each spring strip is to be taken into consideration in isolation, for the production of an individual connection terminal, without direct connection with the spring strip of the other connection terminals of the same type as can further present such electrical equipment.

Claims (8)

1. An electrical apparatus of automatic connection type, in particular a connector for electric leads, of the kind comprising, in a casing (13) of insulating material having at least one entry passage (14) for introducing the conducting core (12) of an electric lead (11), a U-shaped metal member (25), referred to herein as the guide, and a spring plate member (40) which extends at an inclined angle with respect to the axis of said entry passage (14) between the limbs (26, 27) of the guide (25) and which, when the conducting core (12) of an electric lead (11) is engaged in such an entry passage (14), is arranged to apply said conducting core (12) against one of said limbs (26) of said guide (25), characterised in that, by means of a bent-over portion (43), said spring plate member (40) is engaged on to the other limb (27) of the guide (25), such that it bears both against the inward face of said limb (27) and against the outward face thereof.

2. An electrical apparatus according to claim 1, characterised in that, between the limbs (26, 27) of the guide (25), the bent-over portion (43) of the spring plate member (40) forms a spring loop (44).

3. An electrical apparatus according to claim 2, characterised in that, on the inward face of the limb (27) of the guide (25), the bent-over portion (43) of the spring plate member (40) bears against said limb (27) by way of an elbow bend (45) and it bears against the outward face of said limb (27) by way of a flat portion (47).

4. An electrical apparatus according to any one of claims 1 to 3, characterised in that, to cooperate. with the conducting core (12) of an electric lead (11), a tongue portion (50) is cut out at the free end of the spring plate member (40), said tongue portion (50) being bent in the direction of the limb (26) of the guide (25) against which such conducting core (12) is to be applied.

5. An electrical apparatus according to claim 4, characterised in that the active edge of the tongue portion (50) of the spring plate member (40) is set back with respect to the body portion thereof.

6. An electrical apparatus according to any one of claims 1 to 4 wherein, on the outside of the guide (25), the bent-over portion (43) bf the spring plate member (40) comprises at least one opening (48) by means of which it is engaged with a projection (37) which is fixed with respect to the limb (27) of the guide (25), on to which limb it is engaged, characterised in that said projection (37) is formed by a tongue portion which is cut out from the limb (27) concerned of the guide (25) and projects above said limb (27), in moving away from the free edge thereof.

7. An electrical apparatus according to any one of claims 1 to 6, and wherein the central portion (30) of the guide (25) comprises an aperture (33) in line with an entry passage (14) of the casing (13), characterised in that said central portion (30) of said guide (25) extends beyond the spring plate member (40) with respect to said entry passage (14), the concavity of the guide (25) being towards said entry passage (14).

8. An electrical apparatus according to any one of claims 1 to 7, and wherein, being a connector, the casing (13) is provided in side-by-side relationship with a plurality of entry passages (14) and is formed by a hollow body (15) in the form of a finger of a glove and a closure wall (16) which is fitted to said body (15), characterised in that the entry passages (14) of said casing (13) are formed in said wall (16) closing same.

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