FR3060873A1 - ELECTRICAL CONNECTING ELEMENT WITH CONTACT ELEMENT - Google Patents

Abstract

The invention relates to an electrical connection element (1) comprising a metal conductive body (100) made in a first material and housing a spring blade (200), said spring blade being adapted to press against an inner face of a wall ( 103) of the body the stripped core (4) of a conductive wire (2) inserted into said connection element. According to the invention, this inner face of the wall (103) of the body is provided with a contact element (115) made in a second material different from the first material, against which said leaf spring (200) is adapted to press said denuded core of the conductive wire when the latter is inserted into the connection element, said second material having a contact resistance with the stripped core of the electrical wire less than the contact resistance between the first material and this stripped core of the wire electric.

Description

Technical field to which the invention relates

The present invention relates to an electrical connection element comprising a metallic conductive body made of a first material and accommodating a spring blade, said spring blade being adapted to press against an internal face of a wall of the body of the bare core of a wire. conductor inserted in said connection element.

It also relates to a method used to manufacture such an electrical connection element.

Technological background

Such connection elements are known as described in the introduction, for example for electrical sockets.

The role of such a connection element is to transport the current between the electrical wires of the electrical network and the electrical plug belonging to an electrical appliance which is plugged into this connection element. The connection element includes for this purpose a part adapted to receive an electric wire coming from the wall and a receiving socket adapted to receive the pin of the electric plug to put them in electrical contact.

Such an electrical connection element must comply with certain standards.

For example, international standards require that the temperature rise of an electrical outlet due to its heating in operation remains below a heating threshold value set according to the nominal current of the electrical outlet.

One solution for reducing the heating of the connection element is to produce the body of the connection element in a material having as low an electrical resistance as possible, this body being entirely covered with a coating limiting the resistance of contact with the bare soul of the electric wire. In fact, heating of the connection element increases with the electrical resistance introduced by it into the electrical circuit.

The electrical resistance of the connection element is linked to various parameters, in particular the volume resistance of the material (linked to its conductivity) and the contact resistance between the stripped core of the electric wire and the connection element. The body is usually made of raw brass. It is also known to make it entirely in brass coated with materials such as tin, silver or gold. This makes it possible to have a contact resistance with the bare core of an electric wire less than the contact resistance between the raw brass and the bare core of the electric wire. However, the cost of such coated brass is high.

Object of the invention

In this context, the present invention provides a connection element in which heating during the electrical connection of a wire | electricity is reduced while limiting costs.

More particularly, according to the invention, an electrical connection element is proposed as described in the introduction, in which the internal face of the wall of the body is provided with a contact element made of a second material different from the first material, against which said leaf spring is adapted to press said bare core of the conductive wire when the latter is inserted into the connection element, said second material having a contact resistance with the bare core of the electric wire less than the contact resistance between the first material and this bare soul of the electric wire.

Thanks to the connection element according to the invention, it is possible to limit heating of the body of this connection element during the passage of electric current by reducing the contact resistance between the stripped core of the electric wire and the body, while by limiting the manufacturing costs of the connection element. This is achieved by means of a contact element made of a material having a contact resistance with the stripped core of the electric wire less than that of the material from which the rest of the connection element is made and disposed inside. the connection element. Other non-limiting and advantageous characteristics of the element of [connection according to the invention are as follows: j - said second material contains tin, silver or gold; - said first material contains copper; - At least two contact elements made of the second material are provided and said leaf spring is adapted to press the stripped core of the electric wire against at least one of two contact elements; - At least two contact elements made of the second material are provided and said leaf spring is adapted to press the stripped core of the electric wire against the two contact elements simultaneously; - Each contact element extends projecting towards the inside of the body, with respect to the internal face of said wall; - Each contact element belongs to a rivet fixed through said wall; - Each contact element belongs to a patch attached to said internal face of the wall; - Said body comprises at least two insertion lanes adapted to guide the insertion of the stripped core of the electric wire into the connection element, each of the insertion lanes being delimited at least partially by said internal face of the wall of the body, and at least one contact element being disposed in each insertion corridor. The invention also relates to electrical equipment comprising a connection element as described above, for the electrical connection of an electrical wire.

In particular, this electrical apparatus constitutes a socket for the electrical connection of said electrical wire and of a connection pin belonging to another electrical apparatus. The invention finally relates to a method of manufacturing an electrical connection element as described above, comprising a metallic conductive body made of a first material and housing a leaf spring, said leaf spring being adapted to press against an internal face of a wall of the body the bare core of a conductive wire inserted in said electrical connection element, this internal face of the wall of the body being provided with a contact element made of a second material having a contact resistance with the stripped core of the electric wire lower than the contact resistance between the first material and this stripped core of the electrical wire, according to which said body is made from the first material, then the element is fixed to the internal face of the wall of this body contact made in the second material.

According to this method, an orifice is drilled in said wall of the body and a rivet made of the second material is fixed thereto.

As a variant, a pellet made of the second material is welded to the internal face of said wall.

Detailed description of an exemplary embodiment

The description which follows with reference to the appended 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: - Figure 1 is a schematic rear perspective view of a first embodiment of the electrical connection element according to the invention, - Figure 2 is a schematic rear perspective view of the body of the 'electrical connection element of Figure 1, - Figure 3 is a schematic rear perspective view of the leaf spring of the electrical connection element of Figure 1, - Figure 4 is a rear view of the element of connection of Figure 1, - Figure 5 is a schematic front perspective view of the electrical connection element of Figure 1, - Figure 6 is a schematic front perspective view of the body of the electrical connection element of Figure 5, - Figure 7 is a schematic front perspective view of the leaf spring of the electrical connection element of Figure 5, - Figure 8 is a schematic top view of the connection element electric ion of Figure 1, - Figure 9 is a schematic top view of the body of the electrical connection element of Figure 8, - Figure 10 is a schematic top view of the leaf spring of the element electrical connection of Figure 8, - Figure 11 is a schematic profile view of the electrical connection element of Figure 1, - Figure 12 is a schematic profile view of the leaf spring of the connection element of Figure 11, - Figure 13 is a schematic exploded front perspective view of the electrical connection element of Figure 5, - Figure 14 is a schematic exploded rear perspective view of the electrical connection element of Figure 1, - Figure 15 is a schematic sectional view along the plane P1 of Figure 8, - Figure 16 is a schematic sectional view, similar to that of Figure 15, with the stripped core of an electric wire inserted in the element ent ent, - Figure 17 is a schematic rear perspective view of a second embodiment of the electrical connection element according to the invention, - Figure 18 is a schematic sectional view similar to that of Figure 16 for the second exemplary embodiment.

In the two embodiments shown, identical or corresponding elements will be referenced by the same signs.

In Figures 1 to 16, on the one hand, and 17 to 18, on the other hand, there is shown a two embodiments of the connection element 1 according to the invention. The connection element 1 according to the invention is intended to be integrated into electrical equipment, for example into an electrical outlet. The electrical equipment according to the invention comprises at least one connection element for the electrical connection of an electric wire.

In particular, this electrical apparatus constitutes a socket for the electrical connection of said electrical wire and of a connection pin belonging to another electrical apparatus.

It authorizes the transport of electric current between the electric wires of this equipment, for example the electric wires of the electric network connected to the socket, and a connection pin plugged in this electric equipment, belonging for example to an electrical plug. another electrical appliance.

This connection element 1 comprises for this purpose a conductive body 100 comprising a housing 110 adapted to accommodate at least one stripped core 4 of an electric wire 2 (FIGS. 16 and 18) and a cell 120 adapted to accommodate the connection pin of the electrical plug (not shown) for bringing the electrical wire into electrical contact with the connection pin. The connection element 1 further comprises a spring blade 200 adapted on the one hand to clamp the electric wire 2 introduced into the housing 110 against a base wall 103 of this housing 110, and on the other hand, to clamp the pin connection inserted into the connection socket 120 (Figures 1, 5, 8, 11, 13, 14, 15, 16, 17 and 18).

The electric wire 2 more precisely comprises a stripped core 4 enveloped in an insulating sheath 3 (Figures 16 and 18).

More specifically, here, the leaf spring 200 is adapted to press the stripped core 4 stripped of the conductive wire 2 inserted in the housing 110 against the base wall 103 (Figures 16 and 18) of this housing 110 and is adapted to press the at least one wall of the connection socket 120 against the connection pin, when the latter is introduced into said connection socket 120. The connection element 1 extends generally along a longitudinal axis X1 orthogonal to a direction of insertion I of the connection pin into the cell 120. The direction of insertion I corresponds to the longitudinal axis of the receiving cell 120 (FIGS. 1, 5, 8, 13, 14 and 17).

The body 100 of the connection element 1 is more particularly shown in FIGS. 1, 2, 4, 5, 6, 8, 9, 11, 13, 14 and 17.

The body 100 is made of a first material having a satisfactory first electrical conductivity for conducting the electric current between the connection pin and the electric wire 2.

It is for example a conductive metal, for example copper or an alloy containing copper.

The body 100 is here formed of a fire bent metallic bacon.

This body 100 here comprises two lateral wings 101, 102 which extend from the base wall 103, generally along the longitudinal axis X1.

The base wall 103 is substantially planar and extends perpendicular to the longitudinal axis X1 of the connection element 1 (FIGS. 8, 9 and 17).

Each side wing 101, 102 forms, successively from the base wall 103, a side wall 111, 112 main of the housing 110, an intermediate part 121, 122 curved towards the inside of the connection element 1 and a wall curved 123, 124 towards the outside of the connection element, which partially delimits the cell 120 (FIGS. 1, 2, 5, 6, 8, 9, 13, 14 and 17).

The side walls 111, 112 of the housing 110, defined by the two side wings 101, 102, are planar and extend at right angles from the base wall 103.

This base wall 103 then forms a third side wall of the housing 110 (FIGS. 1, 2, 4, 5, 8, 9 and 17).

The housing 110 of the connection element 1 then has a generally parallelepiped shape delimited by the two main side walls 111, 112, the base wall 103 and said intermediate parts 121, 122 of the side wings 101, 102 (FIGS. 1, 2 , 5, 6, 8, 9, 13, 14 and 17).

This housing 110 is thus practically closed on four faces by said side walls 111, 112, 103 and said intermediate parts 121, 122 of the side wings 101, 102.

It is completely open on two opposite sides.

The housing 110 thus constitutes a space for insertion of the electric wire into the connection element 100, which here extends in a direction E1 parallel to the direction of insertion I of the connection pin in the socket (FIGS. 2 , 6, 9 and 11).

The direction E1 of insertion of the electric wire is therefore here orthogonal to the longitudinal axis X1 of the connection element 1.

The housing 110 is open along this direction E1.

In addition, the base wall 103 of the housing 110 has a flat 105, forming two walls 106 which rise from the internal face of this base wall 103, parallel to the side walls 111, 112 of the housing 110 (FIGS. 5 , 6, 8 9 and 17), towards the interior of the housing 110.

These walls 106 extend longitudinally in the direction E1 of insertion of the electric wire into the housing, over a large part of the height of the housing 110 (Figures 1,2, 5, 6, 8, 9, 13, 14 and 17 ).

Thus, each wall 106 delimits with the side wall 111, 112 of the adjacent housing 110, an insertion corridor 107, 108 (FIG. 9) of the stripped core 4 of the electric wire 2, which guides the introduction of the core stripped 4 of the electric wire 2 in this housing 110.

Remarkably, the internal face of the base wall 103 of the body 100 is further provided with a contact element 115 (FIGS. 8, 9, 15, 16, 18) made of a second material having a contact resistance with the bare core of the electric wire less than the contact resistance between the first material and this bare core of the electric wire, against which said blade j spring 200 is adapted to press said bare core 4 of the conductive wire 2 when the latter is inserted in Connection item 1.

This second material is different from the first material.

It is a contact element having dimensions that are small compared to the dimensions of the base wall.

However, it can take different forms, It can in particular be | present in the form of a contact grain or a pellet, but other forms are also possible, for example a strip form.

One can also provide that the base wall 103 comprises a plurality of contact elements 115 against which the leaf spring 200 is adapted to press simultaneously or not the stripped core 4 of the electric wire 2. j

In the first embodiment shown in FIGS. 1 to 16, as shown more particularly in FIGS. 1, 2 and 4, the connection element 1 here more specifically comprises two contact elements 115.

The contact elements 115 are arranged on the internal face of the base wall 103 so that the leaf spring 200 presses the stripped core 4 of the electric wire 2 inserted into the housing 110 against at least one of the contact elements 115.

In practice, here, each contact element 115 is arranged in one of the insertion corridors 107, 108 delimited between the low walls 106 and the adjacent side walls 111, 112 (FIGS. 8 and 9), near the entrance. of the housing 110. The entry of the housing 110 corresponds to the open face of the housing 110 located closest to the second end portion 220 of the leaf spring 200, which will be described in more detail later.

As a variant, the contact element can be placed in the middle of the insertion corridor for the stripped core of the electric wire, or at any location ensuring electrical contact between the contact element and the stripped core of the electric wire.

Here, a contact element 115 is provided in each of the two insertion corridors 107, 108 of the housing 110, and the stripped core 4 of the electric wire 2 is therefore brought into contact with one of the two contact elements 115 which that is the insertion corridor 107, 108 into which it is introduced.

Alternatively, a plurality of contact elements can be provided in each insertion path of the housing.

Thus, in the second embodiment shown in FIGS. 17 and 18, two contact elements 115 are provided in each insertion passage 107, 108 of the housing 110. These contact elements are here placed near the entrance and from the outlet of the housing 110. With the exception of the number of contact elements arranged on the internal face of each insertion channel, the connection element according to the second embodiment of FIGS. 17 and 18 is entirely similar. to that of the first example of embodiment. The stripped core is then pressed against at least one of the two contact elements 115 of the insertion passage 107, 108 in which it is inserted.

The contact between the contact element and the stripped core of the electric wire is then ensured, regardless of the direction in which the stripped core is inserted into the insertion passage. When the bare core of the electric wire is inserted parallel to the direction E1 of insertion into the housing 110, the bare core 4 of the electric wire 2 is pressed simultaneously against the two contact elements 115, which contributes to reducing the resistance contact of the assembly.

It may happen that the electric wire is stressed in a direction orthogonal to the direction of insertion E1. The stripped core 4 of the electric wire can then be placed in the housing in a direction inclined relative to the direction of insertion E1.

In this situation, the presence of two contact elements 115 ensures that the stripped core 4 of the electric wire 2 is in contact with at least one of the two contact elements 115. For example, if the electric wire is drawn from the side of the receiving cell (to the left in FIG. 18), the stripped core 4 of the electric wire remains in contact with the contact element 115 disposed near the outlet of the housing 110. If the wire electric is pulled from the side opposite to the receiving cell (to the right in Figure 18), the stripped core 4 of the electric wire remains in contact with the contact element 115 disposed near the entrance of the housing 110 .

The contact between the contact element 115 and the stripped core of the electric wire is exerted here on a reduced area of the stripped core due to the small dimensions of the contact element (s).

Said second material preferably contains tin, silver, gold or another precious metal such as palladium, rhodium or platinum.

In practice it is, for example, copper or tinned brass, that is to say copper or raw brass coated with tin, a copper / tin alloy, tin, an alloy of metals comprising gold, silver or another precious metal such as palladium, rhodium or platinum or a metal such as brass coated with gold, silver or another precious metal such as palladium, rhodium or platinum.

Copper or brass can be coated with tin, gold, silver for example by a method of electroplating, compacting, co-laminating or co-rolling with brazing.

In general, the contact resistance existing between the second material and the stripped core of the electric wire can be measured by any method known to those skilled in the art.

This is to measure the potential drop between the stripped core of the electric wire 2 and the contact element 115 made of this second material, therefore on either side of the contact interface, for the application of a given setpoint current. The contact resistance is deduced from this measurement.

The contact resistance can in particular be measured for the application of a low current, for example of the order of 10 to 100 milliAmps, and / or for the application of the nominal current of the connection element 1, for example between 16 and 20 Amps.

We will preferably compare the contact resistance between the second material and the stripped core of the electric wire and the contact resistance between the first material and the stripped core of the electric wire measured for the same value of the intensity of the electric current.

The contact resistance can be measured under operating conditions of the connection element, that is to say in the chemical and mechanical environment of use and after a certain aging of the connection element. We will preferably compare the contact resistance between the second material and the stripped core of the electric wire and the contact resistance between the first material and the stripped core of the electric wire measured for similar operating conditions.

The contact resistance between the first material and the stripped core of the electric wire is for example measured in a contact element similar to that of the invention, but having no contact element.

This contact resistance depends in particular on the hardness characteristics, sensitivity to mechanical stresses and the resistance to chemical aggressions of the material.

For example, with a second relatively soft material such as tin, the oxides that can form on the surface of the contact element are cracked when the stripped core of the electric wire is pressed against this contact element, which reduces the contact resistance between the stripped core of the electric wire and the contact element.

More specifically, here, each contact element 115 belongs to a rivet 117 (see in particular Figures 13 to 16).

The base wall 103 is thus equipped with two rivets 117 produced in said second conductive material. These are 117 rivets made of pewter.

Each rivet 117 is riveted on the base wall 103, through an orifice 116 in this base wall 103 (FIG. 14). Each rivet 117 has two ends 115, 118 which extend in projection relative to said base wall 103 (FIGS. 15, 16 and 18). The internal end 115 of the rivet 117 then projects from the wall 103, towards the inside of the housing 110 (FIGS. 15, 16 and 18), and constitutes the contact element 115.

According to an alternative embodiment not shown here, the contact element belongs to a patch attached to said internal face of the base wall of the housing.

This patch is, for example, welded onto said internal face of the base wall at the point where the internal end 115 of the rivet 117 projects in the example of embodiment detailed here.

The two side walls 111, 112 of the housing 110 are extended by the two intermediate curved parts 121, 122 which approach each other, then by the two arched walls 123, 124 which delimit the cell 120 therebetween.

This cell 120 generally has the shape of a cylindrical sleeve whose longitudinal axis extends along the direction of insertion I (Figures 1, 2, 5, 6 and 17).

The intermediate parts 121, 122 of the side wings 101, 102 connect the edges of the main side walls 111, 112 to the arched walls 123, 124 of the cell 120.

Each intermediate part 121, 122 successively comprises, starting from the corresponding main side wall 111, 112, a fold 104 towards the inside of the connection element 1, a curved portion 121 A, 122A towards the outside, and a flat portion 121 B, 122B. The two flat portions 121 B, 122B extend parallel to one another, close to one another (Figures 2, 5 and 8).

The fold 104 here has a radius of curvature less than that of the arched portion 121 A, 122A (FIGS. 5, 6 and 9).

Each of the planar portions 121 B, 122B is extended by one of the arched walls 123, 124 partially forming the cell 120. Each arched wall 123, 124 is arched towards the inside of the connection element 1 and has the along the insertion direction I, one end 123A, 124A which is flared so as to facilitate the insertion of the connection pin into the socket 120 (FIGS. 1, 2, 6, 8, 9 and 17).

Note that here, the inlet of the housing 110 and the flared inlet of the cell 120 are arranged on either side of the connection element 1, imposing a direction of insertion of the electric wire and the pin opposite connection.

The leaf spring 200 has the shape shown in Figures 3, 7, 10 and 12 to 18. The leaf spring 200 of the first and second embodiments are identical.

The leaf spring 200 of the connection element 1 according to the invention is formed in one piece by a metal strip, a first end portion 210 of which has a longitudinal slot 210A separating two branches 211, 212 adapted to clamp the curved walls 123, 124 of the socket 120 against the connection pin (not shown) and a second end portion 220 of which is adapted to clamp the bare core of the conductive wire inserted in the housing 110 against the base wall 103 and the contact element 115.

The first end part 210 has a free end 201 and the second end part 220 has a free end 202.

The leaf spring 200 has, flat, a substantially rectangular outline, slightly tapered at its first free end 201, which extends along a longitudinal direction.

It has two bent portions 233, 234 around a first transverse axis T1 and a second transverse axis T2 parallel to T1. These two transverse axes T1, T2 are perpendicular to the longitudinal direction of the metal strip.

Seen in profile, the leaf spring 200 thus has an overall S shape (FIG. 12), with the first and second end portions 210, 220 which extend respectively from one of said bent portions 234, 233 towards the one of the free ends 201, 202 of the spring blade 200 and a central part 230 situated between the two bent portions 233, 234.

These three parts 210, 220, 230 of the leaf spring 200 are planar.

The longitudinal slot 210A here extends in the plane of the spring blade 200, along the first end portion 210, of one of the bent portions 234 and, partially, along the central portion 230 of the blade spring 200 (Figures 3 and 10).

It separates the first end part 210 of the spring leaf 200 into two front branches 211,212 (FIGS. 3 and 10).

Said two front branches 211, 212 of the first end portion 210 extend along a mean plane of the leaf spring 200 and are adapted to move elastically from one another parallel to this mean plane during the introduction of the connection pin into the connection element 1.

Furthermore, here, the second end portion 220 of the leaf spring 200 is also separated into two rear branches 221, 222 by another longitudinal slot 240 (FIG. 10). The free end of each of the two rear branches 221, 222 further comprises a notch adapted to match the outline of the stripped core 4 of the electric wire 2 introduced into the housing 110 of the body 100 of the connection element 1 (figures 8 and 10).

In practice, the spring leaf 200 is housed in the body 100 so that the second end portion 220 and the third central portion 230 of the spring leaf 200 are housed in the housing 110 of the body 100 (FIGS. 1, 5, 15, 16 and 18).

As shown in FIGS. 1, 5, 8, 15, 16 and 18, the central part 230 of the leaf spring 200 is applied against a part of the internal face of each arched portion 121 A, 122A of each intermediate part 121, 122 of each lateral wing 101, 102 of the body 100 of the connection element 1. It then extends substantially parallel to the direction of insertion I of the connection pin in the socket 120.

The leaf spring 200 has a width substantially equal, to within one clearance, to the width of the insertion space formed internally by the housing 110 of the body 100, with the exception of a central zone of the spring leaf 200 which has a greater width because two ears 231, 232 extend locally from the edge of the leaf spring 200 (Figure 3).

The leaf spring 200 in fact comprises means for holding in the housing 110, which cooperate in retaining with means complementary to the body 100 of the connection element 1.

More precisely, here the central part 230 of the spring leaf 200 comprises the two ears 231, 232 which extend in the plane of this central part 230 of the spring leaf 200, towards the outside of the spring leaf (FIGS. 3, 7 and 10).

Each of these ears 231, 232 is received in a window 109 of the body 100 of the connection element 1, located here at the level of the fold 104 connecting the arched portion 121 A, 122A of the intermediate part 121, 122 of each lateral wing 101, 102 to the corresponding side wall 111, 112 of the housing 110 (Figures 1, 5 and 11).

The leaf spring 200 is thus mounted by snap-fastening in the body 100 of the connection element 1.

The shape of the ears 231, 232 allows the spring blade 200 to be held in the housing 110 when the stripped core 4 of the electric wire 2 is inserted.

The second end portion 220 of the spring leaf 200 extends across the housing 110, and the free end 202 of the second end portion 220 of the spring leaf 200 bears against the internal face of the wall base 103 of the housing 110 (FIG. 7) when no conductive wire is inserted in the housing 110. Here, in addition, the free end 202 of the second end portion 220 of the leaf spring 200 rests against the contact element 115 at rest.

The leaf spring 200 can be slightly prestressed so that this second end portion 220 of the leaf spring 200 permanently exerts pressure against the internal face of the base wall 103 of the housing 110 and / or on the contact element 115.

More specifically, as shown in FIG. 8, the free end of each of the two rear branches 221, 222 of the second end part 220 of the leaf spring 200 is shaped so as to be housed in one of the two corridors insertion 107, 108 of the electric wire. The free end of each rear branch 221, 222 thus extends across one of the insertion corridors 107, 108, between one of the side walls 111, 112 of the housing 110 and the adjacent wall 106, and is in abutment against the base wall 103 and / or the contact element 115 (FIG. 15) when the stripped core 4 of the electric wire 2 is outside the housing 110 of the connection element 1.

As a variant, the leaf spring can be housed at rest in said housing. The free end of each rear branch is not necessarily in contact with the base wall and / or the contact element before the introduction of the stripped core of the electric wire.

The first end portion 210 of the leaf spring 200 emerges from the housing 110 and extends in the direction of the cell 120 (Figures 11 and 17).

This first end portion 210 of the spring leaf 200 then extends here substantially perpendicular to the direction of insertion I of the connection pin in the socket.

More specifically, here, the first end part 210 of the leaf spring 200 emerges near the flared end 123A, 124A of the arched part 123, 124 of the side wing 101, 102 (FIGS. 11 and 17).

In addition, as shown in FIGS. 1, 5 and 8, a part of the body 100 of the connection element 1 extends in the longitudinal slot 210A, between the front branches 211, 212 of the spring leaf 200. It s here acts of a part of the planar portion 121 B, 122B of the intermediate part 121, 122 of each lateral wing 101, 102 of the body 100 of the connection element 1.

Indeed, as shown in FIG. 10, the height of each lateral wing 101, 102 of the body 100, measured according to the direction of insertion I of the connection pin, is lower at the level of the arched portion 121 A, 122A of the intermediate part 121, 122 of this lateral wing 101, 102 only at the level of the flat portion 121 B, 122B of the intermediate part 121, 122.

This allows the first end portion 210 of the spring blade 200 to emerge above the edges of the arched portions 121 A, 122A of the intermediate portions 121, 122, so that the free ends of the front legs 211, 212 of the first end part 210 of the spring blade 200 surrounds the ends of the flat portions 121 B, 122B of the intermediate parts 121, 122 of the lateral wings 101, 102 (FIGS. 1 and 5).

The leaf spring 200 is thus adapted to cooperate with said wings of the body 100 so as to limit the spacing of the arched parts 123, 124 of the lateral wings 101, 102 delimiting the cell 120.

Here, in the standby position, when no pin is inserted in the receiving socket 120, the free ends of the front legs 211, 212 of the first end portion 210 of the leaf spring 200 are in contact with the flat portions 121 B, 122B of the intermediate parts 121, 122 of the lateral wings 101, 102, without exerting pressure on them.

Alternatively, in the standby position, the free ends of the front legs of the first end part of the leaf spring may be out of contact with the ends of the flat portions of the intermediate parts of the lateral wings.

Alternatively also, in this waiting position, the free ends of the front legs of the first end part of the leaf spring can pinch the ends of the flat portions of the intermediate parts of the side wings.

The material of the spring blade has satisfactory rigidity characteristics to play its role of tightening the electric wire and the connection pin. It need not be made of a conductive material, which makes it possible to limit the amount of conductive material used to manufacture the connection element according to the invention. The spring leaf is for example made of steel, in particular stainless steel.

In practice, thanks to the connection element 1 according to the invention, heating of the connection element 1 during the passage of the electric current from the electric wire to the connection element is limited.

When inserting the stripped core 4 of the electric wire 2 into the housing 110, the second end portion 220 of the leaf spring 200 is adapted to bend slightly around the first transverse axis T1 to allow the introduction of this bare soul in the corresponding housing 110.

Thus, when the stripped core 4 of an electric wire 2 is introduced into the housing 110, along one of the insertion corridors 107, 108, the second end part 220 flexes towards the central part 230 of the leaf spring 200 so as to free a passage for the bare core 4 of the electric wire in the corresponding insertion corridor (FIG. 16). When the stripped core 4 of the electric wire 2 extends in the insertion corridor, the second end 220 of the spring blade 200 tends to return to its unreflected rest position, thus pressing the stripped core 4 of the electric wire 2 against the internal face of the base wall 103 of the housing 110 and against the contact element 115.

Here, two electrical wires can be introduced into each connection element 1, in the two insertion lanes 107, 108 of the housing 110 described above.

Here, each electrical wire is inserted in a direction perpendicular to the longitudinal axis X1 of the connection element 1 and parallel to the insertion direction I of the connection pin.

Each rear branch 221, 222 is adapted to flex independently of the other rear branch, to allow the insertion of the stripped core 4 of the electric wire 2 in one of the insertion corridors 107, 108, independently of the insertion of an electric wire in the other insertion corridor. The stressed free end 202 of the rear branch 221, 222 then exerts pressure on the stripped core of the electric wire, so as to press it against the contact element 115 and the base wall 103 of the housing 110.

Thus, the stripped core 4 of the electric wire 2 is pressed against the contact element 115 made of the second material having a reduced contact resistance compared to the first material which constitutes the rest of the body of the electrical connection element 1 .

The presence of this contact element 115 interposed between the stripped core 4 of the electrical wire 2 and the part of the body 100 made of the first material makes it possible to reduce the overall contact resistance existing between the stripped core 4 of the electrical wire 2 and the connection element 1 and thus limit heating of the assembly during the passage of the current.

The experimental results obtained by the Applicant show that the overall resistance of the connection element according to the invention provided with tin rivets is similar to that of a connection element entirely made of tinned brass, without contact element.

In addition, the contact element 115 has a reduced size compared to the connection element 1 and requires a small amount of second material to be manufactured. Its installation in the connection element is simple. The connection element 1 according to the invention is therefore inexpensive.

The manufacturing cost of the connection element according to the invention is also limited, since the waste from cutting the material forming the body of the connection element (copper or brass for example) can be easily recycled and are therefore resold at a price close to the purchase price. On the contrary, if the body is made entirely of tinned brass for example, not only is this material more expensive to purchase, but it is also more difficult to recycle since the tin must be separated from the brass. Cutting waste is then sold at a price much lower than the purchase price. The connection element according to the invention is therefore economical to produce.

Furthermore, in the example described of the connection element, the functions of electrical conduction and tightening of the connection pin and the electric wire are decoupled.

The electrical conduction is ensured only by the body 100, while the leaf spring 200 ensures the tightening of the connection pin in the connection socket 120 and the electric wire in the housing 110.

In addition, the tightening of the connection pin and that of each electric wire is ensured independently.

In fact, during the insertion of the connection pin into the socket, the latter is engaged in the socket in the direction of insertion I, from the flared end of the socket 120 towards the inside of cell 120

In doing so, the connection pin tends to separate the arched parts 123, 124 from the side wings 101, 102 from one another.

However, such a spacing immediately generates the spacing of the flat portions 121 B, 122B of the intermediate parts 121, 122 of the lateral wings 10, 102. The spacing of the flat portions 121 B, 122B of the intermediate parts 121, 122 of the lateral wings 101 , 102 is itself strongly limited by the action of the spring blade 200 on these flat portions 121 B, 122B of the intermediate parts 121, 122 of the lateral wings 101, 102.

Indeed, this spacing tends to spread the front legs 211, 212 of the leaf spring 200 in the plane of the leaf spring 200. The leaf spring 200 is then biased in a transverse direction.

The leaf spring 200 has a low elasticity in this transverse direction, and allows only a slight separation of the planar portions 121 B, 122B of the intermediate parts 121, 122 of the lateral wings 101, 102.

Thus, during the insertion of the connection pin into the socket, the front branches 211, 212 of the leaf spring move away from each other, then tend to return to their initial positions.

The leaf spring 200 thus cooperates with said wings of the body 100; 300 so as to oppose the spacing of the arched parts 123, 124 4 of the lateral wings 101, 102 delimiting the cell 120.

In other words, the leaf spring 200; 400 cooperates with said wings of the body 100 in order to bring the arched parts 123, 124 towards the other of the lateral wings 101, 102 delimiting the cell 120.

The front branches 211, 212 of the spring blade 200 recall the flat portions 121 B, 122B of the intermediate parts 121, 122 of the lateral wings 101, 102 towards each other, and with them, the arched parts 123, 124 of the cell, so as to bring said arched parts 123, 124 together.

In doing so, the front branches 211, 212 of the leaf spring 200 ensure the tightening of the connection pin against the arched parts 123, 124 of the cell.

The electrical connection of the electrical wire and the connection pin is thus effectively secured. The connection element according to the invention as described above can be produced in different ways.

In practice, here, the body 100 is manufactured by folding a metal strip of the first conductive material, for example from raw brass.

The windows 109 are drilled in the lateral wings 101, 102 as well as the puncture 105 and the orifices 116 in the base wall 103. This is preferably carried out before the metal strip is folded.

One can then introduce a rivet 117 into each hole 116 and fix it, then finally fold the strip. This is in particular the case during an automated assembly of the connection element 1.

As a variant, in particular during manual assembly, it is possible first of all to perform a maximum of folding of the strip, that is to say those which will not interfere with manual crimping, then to install the rivets 117 and finally to finalize the folding of the strip.

The rivet 117 can be preformed or formed from a wire or a profile of the second material directly in the connection element.

As a variant, instead of drilling the orifices and installing the rivets, two pellets made of the second material are welded to the internal face of said base wall 103. This is preferably done before the metal strip is folded.

We have described here a connection element having a particular non-limiting form. The connection element may have any other suitable form known to those skilled in the art.

It can in particular be a connection element having a single insertion corridor delimited by the housing, into which a single electric wire can be introduced. In this single corridor, there is provided according to the invention one or more contact elements.

It can also be a connection element of different geometry, for example in which the insertion space of the electrical wire or wires in the housing extends in a direction perpendicular to the direction of insertion of the pin. in the socket. Similarly, the leaf spring can have a different shape.

It can also be a simpler connection element, comprising only a housing and a spring leaf, such as an automatic terminal, without a socket for receiving a connection pin. Finally, the number of connection elements and their shape can obviously vary.

Claims (13)

1. Electrical connection element (1) comprising a metallic conductive body (100) made of a first material and housing a leaf spring (200), said leaf spring (200) being adapted to press against an internal face of a wall ( 103) of the body (100) the stripped core (4) of a conductive wire (2) inserted in said connection element (1), characterized in that this internal face of the wall (103) of the body (100) is provided with a contact element (115) made of a second material different from the first material, against which said leaf spring (200) is adapted to press said stripped core (4) of the conductive wire (2) when the latter is inserted into the connection element (1), said second material having a contact resistance with the stripped core of the electric wire less than the contact resistance between the first material and this stripped core of the electric wire. 2. An electrical connection element (1) according to claim 1, wherein said second material contains tin, silver or gold. 3. Electrical connection element (1) according to one of claims 1 and 2, wherein said first material contains copper. 4. electrical connection element (1) according to one of the preceding claims, in which at least two contact elements made of the second material are provided and said leaf spring (200) is adapted to press the stripped core (4 ) electric wire (2) against at least one of the two contact elements. 5. electrical connection element (1) according to one of claims 1 to 4, wherein each contact element (115) projects inwardly from the body (100), relative to the internal face of said wall. 6. electrical connection element (1) according to one of claims 1 to 5, wherein each contact element (115) belongs to a rivet (117) fixed through said wall (103). 7. Electrical connection element according to one of claims 1 to 5, in which each contact element belongs to a patch attached to said internal face of the wall. 8. electrical connection element (1) according to one of claims 1 to 7, wherein said body (100) comprises at least two insertion channels (107, 108) adapted to guide the insertion of the stripped core (4) of the electric wire (2) in the connection element (1), each of the insertion passages (107, 108) being delimited at least partially by said internal face of the wall (103) of the body, and at at least one contact element (115) being arranged in each insertion channel (107, 108). 9. Electrical equipment comprising a connection element (1) according to one of the preceding claims, for the electrical connection of an electrical wire. 10. Electrical equipment comprising a connection element (1) according to the preceding claim, constituting a socket for the electrical connection of said electrical wire and a connection pin belonging to another electrical equipment. 11. A method of manufacturing an electrical connection element (1) according to one of claims 1 to 8, comprising a metal conductive body (100) made of a first material and housing a leaf spring (200), said leaf spring (200) being adapted to press against an internal face of a wall (103) of the body (100) the stripped core (4) of a conductive wire (2) inserted in said electrical connection element (1), this internal face of the wall (103) of the body (100) being provided with a contact element (115) made of a second material having a contact resistance with the stripped core of the electric wire less than the contact resistance between the first material and this stripped core of the electric wire, according to which said body (100) is cut from the first material, then the contact element (115) is fixed on the internal face of the wall (103) of this body (100) ) made of the second material. 12. The manufacturing method according to the preceding claim, according to which an orifice (116) is drilled in said wall (103) of the body (100) and a rivet (117) made of the second material is fixed thereto. 13. The manufacturing method according to claim 11, wherein a pellet made of the second material is welded to an internal face of said wall.