FR3060215A1 - ELECTRICAL CONNECTION ELEMENT WITH INSULATING SHEATHING OF AN ELECTRIC WIRE - Google Patents

Abstract

The invention relates to an insulating sheath electrical connection element (1) formed from at least two separate parts (5, 6) made of materials of different electrical conductivities, these two parts delimiting between them a slot (11). ) of insertion of a sheathed electrical wire (2) having: - a proximal portion (12), situated on the side of its mouth, whose width is reduced towards the bottom (11C) of the slot (11) and whose at least one of the edges (12A, 12B) is made of a first material, - a distal portion (13), located on its bottom side, of which at least one of the edges (13A, 13B), called the connecting edge (13A) , is made of a second material having a better electrical conductivity than the first. According to the invention, the slot has, between the proximal and distal portions, an intermediate portion (14) delimited by two intermediate edges (14A) made of a material different from said second material and in that the connecting edge of the distal portion. the slot extends generally in the extension of one of the two intermediate edges of the intermediate portion of the slot.

Description

Holder (s): LEGRAND FRANCE Public limited company, LEGRAND SNC General partnership.

Extension request (s)

Agent (s): JACOBACCI CORALIS HARLE Simplified joint-stock company.

ELECTRICAL CONNECTION ELEMENT WITH INSULATING SHEATH PIERCING OF AN ELECTRIC WIRE.

FR 3 060 215 - A1 (57) The invention relates to an electrical connection element (1) with an insulating sheath bore, formed of at least two separate parts (5, 6) made of materials of different electrical conductivities, these two pieces delimiting between them a slot (11) for inserting a sheathed electric wire (2) having:

- A proximal part (12), located on the side of its mouth, whose width is reduced towards the bottom (11C) of the slot (11) and of which at least one of the edges (12A, 12B) is made of a first material ,

- A distal part (13), located on the side of its bottom, at least one of the edges (13A, 13B), called connection edge (13A), is made of a second material having better electrical conductivity than the first.

According to the invention, the slot has, between the proximal and distal parts, an intermediate part (14) delimited by two intermediate edges (14A) made of a material different from said second material and in that the connecting edge of the distal part of the slot extends generally in the extension of one of the two intermediate edges of the intermediate part of the slot.

Technical field to which the invention relates

The present invention relates generally to the field of electrical equipment which comprises so-called "insulating piercing" electrical connection elements making it possible to automatically connect (without tools) said equipment to the electrical supply wires coming from the network.

It relates more precisely to an electrical connection element with an insulating sheath bore, formed of at least two separate parts, made of materials of different electrical conductivities, these two parts delimiting between them an insertion slot for a sheathed electrical conductor presenting:

- a proximal part, located on the side of its mouth, whose width is reduced towards the bottom of the slot and at least one of the edges of which is made of a first material,

- A distal part, located on the side of its bottom, at least one of the edges of which, called the connection edge, is made of a second material having better electrical conductivity than the first.

The invention finds a particularly advantageous application in the production of electrical terminals for electrical outlets or electrical switching devices such as simple switches or two-way switches.

Technological background

Generally, provision is made to connect electrical equipment to a current source by three phase, neutral and earth electrical wires connected to three electrical terminals.

The fixing and connection of a sheathed electrical wire can be done using a screw terminal, which consists of a metal strip into which is screwed a screw. The screw is used to tighten the stripped end of the electrical wire to the metal strip in order to establish the electrical connection.

There are also insulation piercing terminals which include a metal body in which a slot is made, and a connection lever. These terminals are said to be "with insulation piercing" in the sense that the tilting of the lever makes it possible to force the wire to engage through the slot so that the edges of the slot cut through the insulating sheath of the electric wire and make the electrical connection with the wire.

In this particular context, it can be seen that the cutting of the insulator is sometimes random, due to the efforts to which the terminal is subjected to cut the insulating sheath, efforts which risk deforming it. In addition, as the electrical wires are connected and disconnected, the edges of the slots become dull so that they sometimes fail to cut the insulating sheath enough to establish the electrical connection.

Object of the invention

In order to remedy the aforementioned drawback of the state of the art, the present invention provides a new bi-material electrical connection element, comprising separate materials intended to ensure distinct functions and a particular geometry.

More particularly, according to the invention, a connection element is proposed as described in the introduction, in which the slot has, between the proximal and distal parts, an intermediate part delimited by two intermediate edges made of a material different from said second material and in which the connection edge of the distal part of the slot extends generally in the extension of one of the two intermediate edges of the intermediate part of the slot.

The electrical connection element according to the invention then comprises a proximal part, made of a rigid material, for effectively cutting the insulating sheath of an electric wire, and a distal part, made of a conductive material, to ensure a good connection. between the conductive core of the electric wire and the connection element. The intermediate part, made of a material different from that of the distal part, makes it possible to provide pickling of the conductive core of the electric wire after slicing its insulating sheath, and a calibration of this conductive core.

Indeed, one of the edges of the intermediate part of the slot being generally in the extension of the connection edge of the distal part, the conductive core of the electric wire is scratched by this edge of the intermediate part, and this part scratched by the conductive core is immediately brought into contact with the connection edge when the electric wire is inserted.

Thus, the cutting of the insulating sheath and the calibration of the conductive core are ensured by two separate parts of the connection element, different from the connection edge.

Thanks to this arrangement, the deterioration of the connection edge usually linked to the insertion and disinsertion of the electric wire into the connection element is limited.

The connection element according to the invention thus permanently allows the establishment of a good quality electrical connection between the electric wire and the second part of the connection element which is made of the material having the electrical conductivity. higher.

Other non-limiting and advantageous characteristics of the connection element according to the invention are as follows:

- The width of the intermediate part of the slot is strictly less than the diameter of the conductive core of the electric wire;

- the width of the intermediate part of the slot is constant;

- The width of the intermediate part of the slot is reduced in the direction of the distal part of the slot;

- one of the edges of the slot is made entirely of the first material, while the other edge is made, for the proximal and intermediate parts, in the first material, and for the distal part, in the second material;

- The proximal part and the intermediate part of the slot are formed in the first part, this intermediate part of the slot extending, in this first part, by a window which houses a portion of said second part;

- the two parts respectively have two flat portions applied one against the other;

- Said second part comprises a flat portion applied against the first part and a bent portion whose free end is housed in said window of the first part;

- the two parts are assembled together in a fixed manner;

- one of the two parts has an opening and the other part has a relief which crosses said opening of the first part;

- said first material comprises stainless steel or steel and said second material contains copper;

- At least one of the edges produced in said first material of the proximal part of the slot is a cutting edge.

The invention also relates to an electrical connection terminal comprising at least one electrical connection element as described above, in which the second part of this electrical connection element is electrically connected to a socket for receiving an electrical connection pin d '' electrical equipment.

The invention also relates to an electrical connection terminal comprising at least one electrical connection element as described above, in which the second part of this electrical connection element is electrically connected to a switch contact.

Finally, the invention relates to electrical equipment comprising an electrical connection element as described above, belonging to a connection terminal for its connection to an electrical network.

Advantageously, the second part of the electrical connection element is electrically connected to a socket for receiving an electrical connection pin of another electrical appliance or to a switch contact.

Detailed description of an exemplary embodiment

The description which follows with reference to the accompanying drawings, given by way of nonlimiting examples, will make it clear what the invention consists of and how it can be carried out.

In the accompanying drawings:

FIG. 1 is a schematic front perspective view of an electrical connection element according to the invention,

FIG. 2 is a schematic rear perspective view of the electrical connection element of FIG. 1,

- Figure 3 is a schematic rear view of the electrical connection element of Figure 1,

- Figure 4 is a schematic view from below of the electrical connection element of Figure 1,

FIG. 5 is a schematic view in straight profile of the connection element in FIG. 1,

FIG. 6 is a schematic front view of the electrical connection element of FIG. 1,

- Figure T is a schematic view in left profile of the electrical connection element of Figure 1,

FIG. 8 is a schematic view from above of the electrical connection element of FIG. 1,

FIG. 9 is a diagrammatic view of the electrical connection element of FIG. 1, with an electric wire approached from the mouth of the slot of this element,

FIG. 10 is a schematic view similar to that of FIG. 9, in which the electric wire is engaged in the proximal part of the slot,

FIG. 11 is a schematic view similar to that of FIG. 9, in which the electric wire is engaged in the intermediate part of the slot,

FIG. 12 is a schematic view similar to that of FIG. 9, in which the electric wire is engaged in the distal part of the slot,

FIG. 13 is a partial schematic perspective view of a connection terminal comprising two connection elements according to the invention,

FIG. 14 is a sectional view of the connection terminal of FIG. 13 along the plane P1,

- Figure 15 is a perspective view of the connection terminal of Figure 13 complete.

In general, the connection element 1 according to the invention is an electrical connection element "with insulation piercing" intended to make an electrical connection between an electrical apparatus and an electrical wire 2 comprising a conductive core 4 surrounded by an insulating sheath 3, such as that shown in FIGS. 9 to 12.

For this purpose, the connection element 1 comprises a slot 11 in which the electric wire 2 is inserted (Figures 9 to 12).

More specifically, the slot 11 extends along a longitudinal axis X and the electric wire 2 is inserted in an insertion direction parallel to this longitudinal axis X of the slot 11.

The electric wire 2 extends along a direction substantially perpendicular to the direction of insertion.

When inserting the electric wire 2 into the slot 11 of this electrical connection element 1, at least one edge of the slot 11 pierces the insulating sheath 3 of the electric wire 2 and comes into contact with the conductive core 4 of the wire electric 2 (Figures 11 and 12).

In order to effectively pierce the insulating sheath 3 of the electrical wire 2 to expose the conductive core 4 of this electrical wire 2, the corresponding edge of the slot 11 must have mechanical characteristics of sufficient rigidity.

In addition, the slot 11 has at least one connection edge made of a material having characteristics of electrical conductivity sufficient to allow electrical connection between the conductive core 4 of the electrical wire 2 and the connection element 1.

In particular, the slot 11 must allow easy insertion of the electric wire 2 while maintaining sufficient pressure on the conductive core 4 to ensure good electrical contact between the conductive core 4 of the wire and the corresponding connection edge of the slot 11, in order to have the lowest possible contact resistance and avoid overheating.

In Figures 1 to 12, there is shown the electrical connection element 1 according to the invention. In Figures 13 and 14, there is shown a connection terminal 100 comprising two of these electrical connection elements 1.

The connection element 1 belongs, for example, to electrical equipment such as an electrical outlet or any switch.

The connection element 1 makes it possible to connect the electrical wire 2 coming from the network to an electrical component of said apparatus for its supply.

As mentioned previously, this electrical connection element 1 comprises a slot 11 for introducing said insulated electrical wire 1. This slot 11 is delimited between two edges 11 A, 11B of the connection element arranged opposite (Figures 1,2 and 6).

In the embodiment shown in the figures, the electrical connection element 1 according to the invention comprises two separate parts 5, 6 assembled.

These two parts are made of two different materials, having different electrical conductivities.

A first part 5 is made of a first material having a lower electrical conductivity than the second material, and a second part 6 is made of this second material, which therefore has greater electrical conductivity than the first material.

Advantageously, said first material also has greater hardness than the second material. In practice, the first part 5 is for example made of a metal such as stainless steel or steel and the second part 6 is for example made of copper or a metal alloy containing copper.

The hardness of a metal defines its resistance to the penetration of a harder body. It is determined by means of standardized tests by measuring the depth, the diameter or another parameter of the impression made by a punch according to the test.

Each of the first and second parts 5, 6 is in the form of a plate. The two plates forming these first and second parts 5, 6 are applied against each other and are assembled together in a fixed manner.

In the example described here, the first part 5 has for this purpose a central opening in which protrudes a relief 6A of the second part 6 (Figures 2, 3, 5, 7, 8).

This relief 6A widens after having crossed the first part 5 so as to wedge the latter. This is for example obtained by stamping the second part 6 to create the relief and riveting of the latter on the first part 5 or by an operation of the snap-fastening type.

In general, the first and second parts 5, 6 are secured by a link preventing any relative movement of one relative to the other. It can for example be a fixing by embedding, clinching, grooving, welding, or riveting.

The first part 5 has a substantially square outline (Figure 3).

It comprises a main part 51 and a secondary part 52 which are flat (FIG. 2). The secondary part 52 is connected to the main part 51 by a bent part 53. This bent part 53 extends parallel to one of the sides of this first part 5 (FIG. 6). This bent part 53 and the secondary part 52 (FIGS. 4 and 8) are folded in the direction of the second part 6.

An opening 20 (Figures 2, 3 and 13) is formed in this first part 5. As explained in more detail later, this opening 20 partially defines the slot 11 for introducing the electric wire 2 as well as a window 21 (Figures 2, 3 and 13) in which a portion of the second part 6 projects.

This opening 20 extends astride the bent part 53, as well as the main part 51 and the secondary part 52 of the first part 5.

More specifically, the window 21 is constituted by the part of the opening 20 extending in the main part 51 of the first part 5.

The second part 6 has a flat main part 61 having a substantially rectangular outline (Figures 1, 6 and 9 to 12). When the first and second parts 5, 6 are assembled, the first three sides of this main part 61 of the second part 6 are flush with the three corresponding sides of the flat main part 51 of the first part 5.

From the fourth side of the planar main part 61 of the second part 6 extends a slightly curved tongue 62 (Figures 1, 4, 6, 8 and 9 to 14), constituting a bent portion of the second part 6. More specifically, this tongue 62 extends in the extension of the main part 61 of the second part, from the edge of this main part 61 and is bent towards the first part 5.

The first and second parts 5, 6 are arranged so that the free end of this tongue 62 extends in the window 21 open in the main part 51 of the first part 5.

The slot 11 for introducing the electric wire 2 (FIGS. 1 to 3, 6 and 9 to 15) is delimited between these two parts 5, 6. The slot 11 is closed, and extends from a mouth towards a bottom 11C, along the longitudinal axis X (Figure 6). This longitudinal axis X is parallel to two parallel edges of the plate forming said first part 5.

The bent portion 53 of the first part 5 further extends along this longitudinal axis X of the slot 11.

Thus, in practice, the slot 11 is formed in this bent part 53 of the first part 5 and opens on an edge of the plate constituting the part 5. This slot 11 has here in a remarkable manner a particular arrangement. More specifically, it includes:

- A proximal part 12, located on the side of its mouth, whose width is reduced towards the bottom of the slot 11 and of which at least one of the cutting edges 12A, 12B is made of said first material (Figures 2, 3, 6 and 9 to 12),

- a distal part 13, located on the side of its bottom 11 C, of which at least one of the edges 13A, called the connection edge, is made of the second material having better electrical conductivity than the first (FIGS. 2, 3, 6 and 9 to 12), and,

an intermediate part 14, situated between the proximal 12 and distal 13 parts, delimited by two calibration edges 14A, 14B produced from a material different from said second material,

- The connection edge 13A of the distal part 13 of the slot 11 generally extending in the extension of one of the two calibration edges 14A of the intermediate part 14 of the slot 11 (Figures 2, 3, 6 and 9 at 12).

The slot 11 for introducing the electrical wire 2 thus here comprises three proximal 12, intermediate 14 and distal 13 portions, which are successively crossed by the electrical wire 2 when the latter is inserted into the slot 11 of the connection element 1 in the direction of insertion parallel to the longitudinal axis X of the slot 11.

Here, the two edges 12A, 12B of the proximal part 12 of the slot 11 belong to the first part 5 of greater hardness.

The edge 12A of the proximal part of the slot 11 belongs to the main part 51 of the first part 5 while the edge 12B of the proximal part of the slot 11 belongs to the secondary part 52 of the first part 5.

Thus, this proximal part of the slot 11 has a rigidity making it possible to easily tear the insulating sheath 3 of the electrical wire 2. In addition, the greater hardness of the first material forming the edges 12A, 12B for cutting the proximal part 12 of the slot 11 ensures that this proximal part 12 does not deform during the insertion of the electric wire 2 and does not become dull during the insertion / disinsertion of the electric wire.

In order to facilitate the tearing of the insulating sheath of the electric wire, at least one of the edges 12A, 12B of this proximal part of the slot 11 is preferably a cutting edge. Here, the two edges 12A, 12B of this proximal part 12 are cutting edges.

To this end, in the connection element 1 shown in FIGS. 1 to 12, the edges 12A, 12B of the proximal part 12 of the slot 11 have a shape suitable for tearing the insulating sheath 4 of the electric wire 2 at the passage of this one in the slot. Here, in practice, the width of the proximal portion 12 of the slot 11 is reduced from the mouth towards the bottom 11C of the slot 11, so as to define, at the junction with the intermediate portion 14 of the slot 11, two sharp edges P arranged opposite which facilitate the tearing of the insulating sheath 3 (see FIG. 2).

In addition, the edges 12A, 12B of the proximal part 12 of the slot 11 belonging to two parts of the first part 5 which are inclined between them, these two edges 12A, 12B are also inclined relative to each other , as well as said sharp edges P. This arrangement facilitates the tearing of the insulating sheath 3 of the electric wire 2 as it passes through this part of the slot 11.

As a variant, the edges of this proximal part of the slot may include one or more cutouts facilitating the cutting of the insulating sheath.

In another variant, the thickness itself of the edges of this proximal part can be thin enough to tear off the insulating sheath.

The edges 12A, 12B for cutting the proximal part 12 of the slot 11 are thus adapted to pierce the insulating sheath 3 of the electric wire 2 when it is introduced into this slot 11.

The insulating sheath 3 of the electric wire 2 is torn and pushed back when inserted into the proximal part 12 of the slot 11 (see FIG. 10).

In the embodiment shown in the figures, the two edges 14A, 14B for calibrating the intermediate part 14 of the slot 11 extend parallel to each other, starting from said sharp edge P of the part proximal 12 of slot 11.

Each calibration edge 14A, 14B is here formed by the edge of a part of the first part 5. More precisely, here, these two calibration edges 14A, 14B are here formed respectively by the edge of the main part 51 and of the secondary part 52 of the first part 5.

The edge of each part of the first part 5 is delimited between two parallel faces 51 A, 51 B, 52A, 52B of the plate forming this part (Figures 1 and 2).

They extend here parallel to the longitudinal axis X of the slot 11, on either side of this axis (see Figure 6).

These two calibration edges 14A, 14B are spaced from each other by a calibrated distance so as to be slightly less than the diameter of the conductive core 4 of the electric wire 2.

This distance also corresponds here to the width of the bent part 53 of the first part 5.

In other words, the width of the intermediate part 14 of the slot 11, that is to say its transverse dimension relative to the longitudinal axis X of the slot 11, is strictly less than the diameter of the core conductor 4 of the electric wire 2.

In this way, when the electric wire 2 is inserted into this intermediate part 14 of the slot 11, the conductive core 4 of the electric wire 2 is started by the edges 14A, 14B for calibrating this intermediate part 14 of the slot 11 ( see figure 11).

The conductive core 4 is thus slightly etched on passing through the intermediate part 14 of the slot 11.

The edge 14A of the intermediate part 14 of the slot 11 belonging to the main part 51 of the first part 5 and the edge 14B of the intermediate part 14 of the slot 11 belonging to the secondary part 52 of the first part 5, these two edges 14A, 14B of the intermediate part 14 of the slot 11 are therefore inclined relative to each other. The stripping of the conductive core 4 of the electric wire 2 is thus facilitated.

After passing through the intermediate part 14, the electric wire 2 is inserted into the distal part 13 of the slot 11.

The distal part 13 of the slot 11 is delimited by two edges 13A, 13B, at least one of which, called the connection edge 13A, is made of the second material which has the greatest electrical conductivity.

According to the invention, this connection edge 13A extends in the extension of one of the calibration edges 14A of the intermediate part 14 of the slot 11.

More specifically, the connection edge 13A is formed by an edge of a slice of a part of the second part. Here, the connection edge 13A corresponds to the edge of the free end of the tongue 62 of the second part 6. It is here one of the edges of the edge of this tongue 62 (FIG. 14).

As a variant, the connection edge may consist of the edge of a part of the second part, for example of the tongue of the second part.

This connection edge 13A generally extends in line with the edge 14A of the intermediate part 14 in that it extends exclusively in the space between the planes which contain the two parallel faces 51 A, 51B delimiting the edge forming edge 14A of the intermediate part 14, this space including the planes themselves (FIG. 14).

The edge of the part of the first part 5 constituting the edge 14A of the intermediate part 14 and the edge of the part of the second part 6 whose edge constitutes the connection edge 13A can be slightly offset one with respect to the other, from the moment of said edge is well located in the space defined above.

When the connection edge consists of the edge of a part of the second part, the edge forming the connection edge extends entirely in the space defined above.

This connection edge 13A thus follows the edge 14A of the intermediate part 14 during the insertion of the electric wire 2.

Here, the tongue 62 being bent in the window 21 of the first part 5, the edge of the free end of the tongue 62 which forms the connection edge 13A extends in the extension of the edge of the main part 51 of the first part 5 constituting the edge 14A of the intermediate part 14. This edge extends here in the plane of this edge 14A of the intermediate part 14, that is to say in the plane of the edge of the first part 5 at the opening 20 which forms the intermediate part 14 of the slot 11.

In practice, the edge forming said connection edge 13A extends in the plane of the edge 14A of the intermediate part 14, to within a manufacturing tolerance.

The connection edge can alternatively be slightly offset from the plane of the edge of the first part 5 forming the edge 14A of the intermediate part 14, while remaining in the space defined above.

Thus, the area of the conductive core 4 started by the edge 14A of the intermediate part 14 of the slot 11 is found in contact with the connection edge 13A of the distal part 13 of the slot 11 when the electric wire 2 is pushed towards the bottom 11C of the slot 11.

This arrangement ensures optimal electrical contact between the conductive core 4 of the electric wire 2 and the connection edge 13A of the distal part 13 of the slot 11. The other edge 13B of the distal part 13 of the slot 11 here is formed in the continuity of the edges 12B and 14B of the proximal 12 and intermediate 14 parts of the slot 11.

They together form one of the edges 11B of the slot 11 which is entirely made of the first material. This edge 11B is straight and it consists of the edge of the secondary part 52 of the first part 5.

The other edge 11A of the slot 11 is made, in the proximal 12 and intermediate 14 parts, in the first material, and in the distal part 13, in the second material. It is delimited by the succession of the edge 12A of the proximal part 12, of the edge 14A of the intermediate part 14 and of the connection edge 13A of the distal part. In practice, this is the edge of the main part 51 of the first part 5 in the proximal and intermediate parts and the edge of the tongue 62 beyond the second part 6. This edge 11A of the slot 11 is generally straight and parallel to the edge 11B of the slot 11.

Alternatively, the edges of the intermediate part can be slightly inclined so that the width of the intermediate part of the slot is reduced in the direction of the distal part of the slot.

The slope of the edges of the intermediate part relative to the longitudinal axis of the slot is for example less than or equal to 5%.

FIG. 13 shows a partial view of a connection terminal 100 comprising two connection elements 1.

The second parts 6 of each of the two connection elements 1 of this terminal are integrated into a receiving cell 110 of an electrical connection pin (not shown) of electrical equipment.

This is a connection pin of circular section.

This receiving cell 110 is formed by the folding of two wings 111, 112 of a metal strip on either side of a flat bottom 113 of this cell 110, so as to form a cylindrical sleeve adapted to receive the spindle of connection.

The flat bottom 113 of the receiving cell 110 is extended laterally at two opposite ends by a portion folded at right angles so as to form the second parts 6 of each connection element 1.

The connection element 1 is thus electrically connected to the receiving cell 110 since it has just been formed therewith.

There is shown in Figures 1 to 12, the connection element 1 of this connection terminal 100, isolated therefrom. The connection element 1 shown in FIGS. 1 to 12 then comprises, along one of the sides of the main part 61 of the second part 6, a return 114 which corresponds to the elbow of the bottom 113 of the cell of reception 110 connecting the main part 61 of the second part 6 of each connection element 1 to the reception cell 110.

In practice, this return 114 comes from formation with the main part 61 of the second part 6 of the connection element 1 and the receiving cell 110.

As a variant, the geometry of the connection terminal can be different from that of the example shown in FIG. 13 and the return can be placed differently on the main part of the second part of the connection element.

In another variant, the connection element can be connected in a different way to the receiving cell. It may therefore not include this return.

According to another variant, the connection element can be connected to a switch contact.

According to another variant, it can be provided that the connection element comprises more than two separate parts, for example three separate parts.

These three separate pieces can be made in three different materials. One of the pieces has for example the edges of the proximal part of the slot, a second piece has the edges of the intermediate part of the slot and the third piece forms the connecting edge of the slot.

Finally, FIG. 15 shows the complete connection terminal 100, which includes the receiving socket 110 as well as the two connection elements 1 described above and a spring leaf 120 which encloses the wings 111, 112 of the receiving socket of so as to constantly push them towards each other to tighten the connection pin when the latter is introduced into the receiving socket thus defined.

Claims (15)

1. Electrical connection element (1) with insulating sheath piercing, formed of at least two distinct parts (5, 6) made of materials of different electrical conductivities, these two parts (5, 6) delimiting between them a slot (11) insertion of a sheathed electrical wire (2) having: - A proximal part (12), located on the side of its mouth, whose width is reduced towards the bottom (11C) of the slot (11) and of which at least one of the edges (12A, 12B) is made of a first material , - a distal part (13), located on the side of its bottom (11 C), at least one of the edges (13A, 13B), called connection edge (13A), is made of a second material having better electrical conductivity that the first, characterized in that the slot (11) has, between the proximal (12) and distal (13) parts, an intermediate part (14) delimited by two intermediate edges (14A) made of a material different from said second material and in that the connection edge (13A) of the distal part (13) of the slot (11) extends generally in the extension of one of the two intermediate edges (14A) of the intermediate part (14) of the slot (11). 2. electrical connection element (1) according to claim 1, wherein the width of the intermediate part (14) of the slot (11) is strictly less than the diameter of the conductive core (4) of the electric wire (2) . 3. electrical connection element (1) according to one of claims 1 and 2, wherein the width of the intermediate part (14) of the slot (11) is constant. 4. Electrical connection element according to one of claims 1 and 2, wherein the width of the intermediate part of the slot is reduced in the direction of the distal part of the slot. 5. Connection element (1) according to one of the preceding claims, in which one of the edges (11 B) of the slot (11) is entirely made of the first material, while the other edge (11 A) is produced, for the proximal (12) and intermediate (14) parts, in the first material, and for the distal part (13), in the second material. 6. Connection element (1) according to one of the preceding claims, in which the proximal part (12) and the intermediate part (14) of the slot (11) are formed in the first part (5), this intermediate part. (14) of the slot (11) extending, in this first part (5), by a window (21) which houses a portion of said second part (6). 7. Connection element (1) according to one of the preceding claims, in which the two parts (5, 6) respectively have two flat portions (51,61) applied against each other. 8. Connection element (1) according to claim 6, wherein said second part (6) comprises a flat portion (61) applied against the first part (5) and a bent portion (62) whose free end is housed in said window (21) of the first part (5). 9. Connection element (1) according to one of the preceding claims, in which the two parts (5,6) are fixedly assembled together. 10. Connection element (1) according to the preceding claim, in which one of the two parts (5) has an opening and the other part (6) has a relief (6A) which passes through said opening of the first part ( 5). 11. Connection element (1) according to one of the preceding claims, in which said first material comprises stainless steel or steel and said second material contains copper. 12. electrical connection terminal (100) comprising at least one electrical connection element (1) according to one of the preceding claims, in which the second part (6) of this electrical connection element (1) is electrically connected to a receiving cell (110) of an electrical connection pin of an electrical apparatus. 13. An electrical connection terminal comprising at least one electrical connection element according to one of claims 1 to 11, in which the second part of this electrical connection element is electrically connected to a switch contact. 14. Electrical equipment comprising an electrical connection element (1) according to one of claims 1 to 11 belonging to a connection terminal (100) for its connection to an electrical network. 15. Electrical equipment according to claim 14, wherein the second part (6) of the electrical connection element (1) is electrically connected to a receiving cell (110) of an electrical connection pin (100) of another electrical appliance or to a switch contact. 1/4 12B P P 2/4