EP1537630A2

EP1537630A2 - Electrical contact terminal comprising an elastic contact blade

Info

Publication number: EP1537630A2
Application number: EP03775496A
Authority: EP
Inventors: Claude Casses; Jean-François CLERC
Original assignee: FCI SA; Framatome Connectors International SAS
Current assignee: FCI SA
Priority date: 2002-08-27
Filing date: 2003-08-26
Publication date: 2005-06-08
Anticipated expiration: 2023-08-26
Also published as: AU2003283522A1; AU2003283522A8; CN100414786C; ES2276127T3; US7140927B2; JP2005537617A; WO2004021519A3; DE60309048T2; WO2004021519A2; EP1537630B1; ATE342589T1; FR2844104A1; CN1685574A; DE60309048D1; US20060121797A1

Abstract

The invention relates to an electrical contact terminal which is obtained by cutting and folding a small electrically-conductive metal plate (13), consisting of a rear part (5) which can be used to connect an electric wire (1) and a front part (3) comprising a first folded blade which forms a contact blade (11, 11') with a complementary contact blade, said contact blade (11, 11') comprising at least one formed part (12, 12') which is disposed in a fold area of the aforementioned contact blade.

Description

Electrical contact terminal provided with an elastic contact blade

Field of the invention

The invention relates to an electrical contact terminal provided with an elastic contact blade whose flexibility ensures better electrical contact with a complementary contact terminal. In particular, the invention relates to a female electrical contact terminal with an elastic contact blade, made in one piece from a cut and folded strip, and intended to receive a complementary male contact terminal. The invention finds applications in the field of electrical or electronic connectors and, in particular, in the field of connectors dedicated to the automotive industry. STATE OF THE ART In the field of connectors, it is sought to produce connectors that are less and less expensive. For this, we seek to design connectors requiring, on the one hand, the least possible material and, on the other hand, the simplest possible manufacturing. To meet these requirements, it is known to produce connectors, or contact terminals, female or male, in one piece from a single plate of electrically conductive sheet metal or metal, called strip, cut and folded to form the desired connector.

In particular, female electrical contact terminals of the cage type are produced. Such a contact terminal has a rear part in which is fixed, by crimping, an electric wire to be connected with another electric wire fixed in a complementary male contact terminal. This female contact terminal also includes a cage-shaped front part, intended to receive the male contact terminal. The female contact terminal may also include a transition part connecting the front part with the rear part. Such a female contact terminal is described in patent application EP-A-0 959 531. The cage of this contact terminal is made from a metal plate, or strip, from which a bottom is cut and formed. , two sides (or side walls) and a ceiling. The ceiling is made in two parts placed side by side. In each side, a tongue is cut and folded intended to form a contact blade by which the electrical contact is established between the female terminal and the complementary male terminal.

Very often, the tongue intended to form the contact blade is cut in the extension of the side of the cage and folded towards the inside of the cage. This is the case in particular in patent application EP-A-0 959 531.

In other female contact terminals, the contact blade can also come from a tongue cut out in the rear part of the cage and folded towards the front of said cage. Generally, each side of the cage also has an orifice through which the contact blade is placed. Whatever the way of making the contact blade (folding forwards or backwards of the cage), the orifice, generally of square shape, is intended to receive a locking pin of the terminal in a cell a connector housing receiving this terminal.

Thus, when the male complementary contact terminal is introduced into the female contact terminal, the contact tail of the male terminal is pinched between the two contact blades of the female contact terminal.

However, the contact blades of the known contact terminals are simply folded towards the inside of the cage. Also, when the contact tail of the male contact terminal is introduced between the two contact blades, it is important that the two contact blades remain in permanent contact with the contact tail. The contact blades must therefore be flexible or flexible. For this one can choose a thin strip which offers great flexibility to the contact blades. However, with a thin strip, there is a high risk of tearing or shearing of the contact blades at the bending zone. Indeed, in general, the female contact terminal is weakened in narrow places and in particular at the intersections of the cutting lines. In fact, because of the cuts, forming and folding of the strip, when the strip is thin, intersections of the cutting lines can shear and / or tear under the action of a lateral mechanical thrust exerted on a wall or parallel to this wall. The risk of cutting and shearing contact blades is further increased if, for any reason, the , _ _{Λ Λ}

WO 2004/021519

3 male and female contact terminals must be disassembled before being reassembled.

On the contrary, if a thick strip is chosen, then the contact blades do not have great flexibility. However, if the contact blades are not flexible, then, under the push of the contact tail being introduced between the contact blades, the latter separate from one another and the electrical contact with the tail. contact is poorly established.

It is thus understood that it is difficult to find a compromise in the thickness of the strip so that the whole of the female terminal is rigid enough not to be weakened at the intersection zones of the cutting lines and so that the blades of contacts are flexible enough to remain in permanent contact with the contact tail of the male contact terminal.

DESCRIPTION OF THE INVENTION The object of the invention is precisely to remedy the drawbacks of the electrical contact terminals described above. To this end, the invention provides an electrical contact terminal, in which the elastic contact blades are made more flexible by means of one or more stampings produced in the bending zone of said contact blades. In particular, the invention relates to female contact terminals, made in one piece in a strip, in which the contact blades are folded inwardly of said contact terminal. In this case, the contact terminal of the invention may also include reinforcing blades bearing against the contact blades to reinforce the latter in the area in contact with the contact tail of the complementary male terminal. More specifically, the invention relates to a female electrical contact terminal obtained by cutting and folding a single plate of electrically conductive metal comprising:

- a rear part allowing a connection with an electric wire, and - a front part comprising, on the one hand, a cage provided with a bottom, a ceiling and two sides and, on the other hand, at at least a first blade, forming a contact blade with a complementary contact terminal, produced in the extension of one of the flanks and folded towards the inside of the cage, characterized in that each flank has a second blade forming a reinforcing blade, folded towards a free end of the contact blade and resting on the free end of this contact blade.

Advantageously, the contact blade comprises at least one deep-drawn formed in a folding zone of said contact blade. Brief description of the drawings

FIG. 1 represents a general view of a female electrical contact terminal according to the invention, before the electrical wire is crimped.

FIG. 2 represents a detailed view of the interior of the cage of the female electrical contact terminal of FIG. 1. FIG. 3 represents a cut strip intended to be folded to form the cage of the contact terminal of FIG. 2 .

Figure 4 shows the strip cut from Figure 3 when folded to form the cage of the contact terminal.

FIG. 5 represents another example of cut strip, ready to be folded.

Detailed description of embodiment of the invention

FIG. 1 represents a top view of a female electrical contact terminal according to an embodiment of the invention. This contact terminal 2 is shown when it is ready to be crimped around an electrical conduction wire 1. In other words, in this figure 1, the female contact terminal 2 is shown when its front part 3 is cut and folded and that its rear part 5 and its transition part 4 are cut and awaiting the introduction and crimping of an electric wire 1.

The rear part 5 of the female contact terminal 2 has a bottom and two sides, of complementary shapes, forming crimping wings. These flanks are shown, in Figure 1, open, that is to say in the position in which they are after folding the strip forming the contact terminal but before crimping the electric wire. These sides are intended to be folded and tightened around the insulator 1a of the electric wire 1 to maintain it in a fixed position in the contact terminal.

The transition part 4 of the female contact terminal 2 also has a bottom and two sides, of complementary shapes. As for the rear part, the sides of the transition part are shown, in FIG. 1, open, that is to say in the position in which they are after folding the strip forming the contact terminal but before crimping electric wire. These sides are intended to be folded and tightened around the stripped area 1b of the electrical wire 1 so that an electrical contact is established between the stripped portion of the electrical wire 1 and the transition portion 4 of the contact terminal. . Thus, when the electric wire 1 has been introduced into the rear and transition parts 5 and 4 of the female contact terminal 2, these rear and transition parts are crimped around the electric wire 1, which makes it possible to electrically connect this wire 1 with another electric wire crimped in a male contact terminal, complementary to the female contact terminal of the invention. The female contact terminal of the invention has dimensions and an external shape identical to those of the female contact terminals of the prior art. It can thus be inserted into a conventional male contact terminal, commonly used in the field of connectors. The male contact terminal, complementary to the female contact terminal of the invention, will therefore not be described here.

The front part 3 of the contact terminal 2 forms a cage comprising a bottom 16 and a ceiling 6 formed of two parts 6a and 6b assembled together to form a substantially flat surface. In an exemplary embodiment, the two parts 6a and 6b fit into each other, thus stiffening the ceiling 6 of the cage. For example, as shown in FIG. 1, the part 6a of the ceiling comprises protruding parts forming tenons 7a and 7b and the other part of the ceiling can comprise notches forming mortises 7c, receiving the tenons of part 6a. The parts 6a and 6b can also be simply placed side by side, without interlocking from one part to the other.

The cage has two sides or side walls 8 and 8 ′, of which only the side 8 is visible in FIG. 1. Each side has a tongue, on the front part of the cage, this tongue being folded towards the inside of the cage to form a contact blade. The contact blades of this female terminal are not visible in this figure. They will be described in detail below, with reference to FIGS. 2 to 4.

The side 8 of the cage has an opening 9 and a second tongue intended to form a reinforcing blade 10. This side 8 and the side 8 ', identical to the side 8, will be described in more detail below. In Figure 2, there is shown, in profile, in a view from the rear of the contact terminal, the interior of the cage of the contact terminal of FIG. 1. For a better understanding of the invention, FIG. 2 represents the cage of the contact terminal of FIG. 1, in which the ceiling 6 has been removed. The fact that there is no ceiling on this cage does not constitute an embodiment of the invention; this is simply to allow a better understanding of the invention by the reader.

We can thus see in this figure 2, the contact blades 11 and 11 'produced by tongues cut in the extension of the sides 8 and 8' of the cage 2. These tongues 11 and 11 'are symmetrical to each other other. Also, only the contact blade 11 will now be described. This contact blade 11 is cut in the extension of the sidewall 8 and folded towards the inside of the cage at an angle of about 135 °, conventional for contact blades. As is conventionally the case, this contact blade is then folded at its free end so as to be substantially parallel to the flank 8.

The two contact blades 11 and 11 'together form a drain intended to facilitate the insertion of a contact tail of the male contact terminal inside the cage of the female contact terminal. The contact blade 11 is separated from the blade 11 'by a space, or air gap, the size of which is adapted to receive the contact tail of the complementary male contact terminal.

According to the invention, the tongue forming the contact blade 11 has stamped 12, located in the area where the tongue is folded inwardly of the cage. These stampings 12 are produced by stamping on the strip, after cutting thereof, but before folding the strip and, in particular, before folding the tongue forming the contact blade 11. The contact blade 1 1 'has stamped 12 ', symmetrical to those of the blade 11. These stampings give the contact blades a certain flexibility., Thus making the contact blades more elastic. In addition, these stampings have the advantage of enlarging the part of the tongue which is folded, which lengthens the contact blade inward and increases the contact area with the contact tail of the male terminal, without requiring a larger amount of strip. These stamps also have the advantage of reduce the stresses of the contact blades in their bending zone.

According to one embodiment of the invention, a single stamping can be produced in each contact blade. According to another embodiment, several stampings are produced in each contact blade. The number of stamps produced essentially depends on the thickness of the strip as well as the flexibility desired for the contact blades.

This figure 2 also shows two tabs forming reinforcing blades 10 and 10 '. These reinforcing blades 10 and 10 ′ are cut in the sides 8 and 8 ′ of the cage of the female contact terminal. Once cut, these second tabs 10 and 10 ′ are folded a first time towards the inside of the cage with an angle of the order of 45 °, then folded again so as to make them substantially parallel to the sides 8 and 8 . The free end of each of these tabs forming the reinforcing blades 10 and 10 'is then in abutment against the inner face of one of the contact blades 11 and 11', respectively. Each contact blade 11 and 11 'is thus reinforced, by pressing on its free end, with a reinforcing blade 10 and 10', which makes it possible to maintain the contact blades 11 and 11 'in position.

In this way, the contact blades 11 and 11 ′ are flexible enough to facilitate the introduction of the contact tail, but they are not likely to remain separated from one another after the introduction of the contact tail. In other words, the flexibility given to the contact blades 11 and 11 ′ by the stampings ensures easy introduction of the contact tail between said blades and the reinforcement blades 10 and 10 ′ ensure that they are held in position against this contact tail. The contact blades can thus remain in permanent contact with the contact tail of the male terminal.

According to one embodiment of the invention, the reinforcing blades 10 and 10 ′ are produced with parts of the strip which are usually cut in the sides 8 and 8 ′ to produce the orifices 9 and 9 ′. Blades _{(reinforcement} are thus produced with a part of the strip that is generally regarded as the waste. Thus, a reinforcement of the contact blades without requiring an additional quantity of the strip. In order to simplify the realization of these reinforcing strip, these can be the width of the openings 9 and 9 '. These openings 9 and 9' can, in this case, be rectangular in shape. In Figure 3, there is shown a cut strip 13, intended to be shaped to produce a female contact terminal according to the invention. On this strip, we have shown in thick lines the cutouts of the strip and in fine lines the areas of folding of the strip, that is to say the locations where the strip will be folded during its shaping. We therefore see in this figure 3, the cutouts 7a-7c intended to form the tenon / mortise assembly of the ceiling 6, the cutouts 10 and 10 'of the tongues intended to form the reinforcement blades, the cutouts 9 and 9' of the orifices and the tongues 11 and 11 'intended to form the contact blades. As can be seen in this FIG. 3, the contact blades 11 and 11 ′ are produced from tongues cut outside the part of the strip intended to form the cage of the contact terminal.

Also shown in this Figure 3, the locations e1 and e1 'of the first folds of the tongues 11 and 11' intended to form the contact blades as well as the locations e2 and e2 'of the second folds of these tongues 11 and 11'. Similarly, the locations e3 and e3 ′ of the first folds of the tongues 10 and 10 ′ intended to form the reinforcing blades have been shown and the locations e4 and e4 ′ of the second folds of these tongues 10 and 10 ′. According to the invention, the tongues 11 and 11 'are stamped, with one or more stampings, in the folding zones e1 and e1 \ These tongues are then folded a first time at the level of the zones e2 and e2' then a second time at the level of zones e1 and e1 ′, that is to say stamped zones. In a variant of the invention, the reinforcing blades may also include one or more stampings produced at the level of the folding zones e3 and e3 ', before folding the strip.

In Figure 4 there is shown, in profile, in a view from the front of the contact terminal, the strip of Figure 3 after folding. It can thus be seen, in this FIG. 4, the contact blades 11 and 11 'folded towards the inside of the cage of the female contact terminal. In the fold of these contact blades, we see a series of stampings 12 and 12 '. As shown in this figure, the stampings may have the form of grooves made in the width of the tongue forming the contact blade. These stampings can also have other forms which can depend on the flexibility sought for the contact blade.

This FIG. 4 also shows, through the orifice 9 ', the reinforcing blade 10' coming from the side 8 'of the cage and folded towards the inside of the cage so as to come into abutment against the contact blade 11' . According to one embodiment of the invention, the reinforcing blade 10 ′ may comprise one or two lateral fins 15 ′ cut out from the strip at the same time as the tongue forming the reinforcing blade. In Figure 4, only one fin has been shown for each reinforcing blade. These lateral fins 15 'and 15 are intended to come into abutment in windows 14' and 14 formed in the ceiling 6 of the cage. In the case where each reinforcing blade comprises two fins, these come into abutment, on the one hand, in a window made in the ceiling of the cage and, on the other hand, in a window made in the bottom 16 of the cage. These windows of sizes adapted to the fins have the role of receiving the fins and, thus, of maintaining the reinforcing blades against the contact blades with a predefined clearance, depending on the width of the window. This clearance corresponds to the clearance allowed for the contact blades, that is to say the movement allowed to the contact blades during the introduction of the contact tail of the male terminal. In other words, these sets of fins and windows make it possible to limit the travel of the contact blades when opening and to protect them against a stress exceeding their elastic capacity, during the introduction of a contact tail. They thus define an air gap between the contact blades.

According to one embodiment of the invention, the bottom 16 and the ceiling 6 each have a cantilevered front part, located opposite the U-shaped section comprising the folding zone of the contact blade.

In another embodiment, it is the contact blades 11 and 11 'which each have one or two lateral fins. This embodiment is shown in Figure 5, in the form of a cut sheet, ready to be folded. The example of strip of FIG. 5 comprises a part intended to form the bottom 16 of the cage and two parts 6a and 6b intended to form the ceiling 6 of the cage. In this example, the two parts 6a and 6b of the ceiling are folded and positioned side by side from one another to form the ceiling. In this embodiment, fins 15, 18 and 15 ', 18' are cut on either side of the free end 19, 19 'of the contact blades 11 and 11'. The fins 15 and 18 can thus come into abutment in windows 14 and 17 formed, respectively, in the ceiling 6 and in the bottom 16 of the cage. Similarly, the fins 15 'and 18' can come into abutment in windows 14 'and 17' formed, respectively, in the ceiling 6 and in the bottom 16 of the cage. The contact blades can also each comprise only one fin; in this case, the fins come into abutment either in the windows 14 and 14 'of the ceiling 6, or in the windows 17 and 17' of the bottom 16. As in the previous embodiment, these fins and these windows make it possible to limit the travel of the contact blades during opening and protect them against stress exceeding their elastic capacity, during the introduction of an additional contact terminal. They thus define a precise air gap between the contact blades. It will be noted that this embodiment in which the fins are produced on the contact blades is easier to implement than the previous embodiment because there is more material available around the contact blades than around the reinforcement blades. . In addition, this embodiment makes it possible to obtain better accuracy of the air gap, that is to say of the distance between the internal faces of the contact blades.

In the embodiments which have just been described, the contact blades are produced by tabs cut in the extension of the front part of the cage. However, the invention can also be implemented in female contact terminals whose contact blades are produced by tabs cut in the rear extension of the cage. The stampings are then made at the rear of the cage. In this case, the reinforcing blades which are produced by tabs cut in the extension of the front part of the cage are supported on the outer face of the contact blades. It is then the reinforcing blades which form the drain. These reinforcing blades have the advantage, in this case, of also comprising one or more stampings, making the drain more flexible.

In general, the production of stampings can be implemented in all contact terminals comprising a folded elastic contact blade, whether male or female terminals, of the cage type or not. .

Claims

1 - Electrical contact terminal obtained by cutting and folding an electrically conductive metal plate (13) comprising: - a rear part (5) allowing a connection with an electric wire (1), and

- a front part (3) comprising, on the one hand, a cage provided with a bottom (16), a ceiling (6) and two sides (8, 8 ') and, on the other hand, d '' at least a first blade, forming a contact blade (11, 11 ') with a complementary contact terminal, produced in the extension of one of the flanks and folded towards the inside of the cage, characterized in that each flank has a second blade (10, 10 ') forming a reinforcing blade, folded towards a free end of the contact blade and resting on the free end of this contact blade. 2 - Contact terminal according to claim 1, characterized in that the contact blade (11, 11 ') comprises at least one stamping (12, 12') produced in a bending zone of said contact blade.

3 - Contact terminal according to claim 2, characterized in that the stamping is carried out on the contact blade before folding of the metal plate.

4 - Contact terminal according to claim 2 or 3, characterized in that the stampings are made in the folded zone of the contact blade towards the inside of the cage.

5 - Contact terminal according to any one of claims 1 to 4, characterized in that it comprises at least one lateral fin (15) produced on at least one of the blades and received in at least one window (14, 17) formed in the ceiling and / or the bottom of the cage.

6 - Contact terminal according to claim 5, characterized in that the lateral fin (15) is formed on a contact blade (11). 7 - Contact terminal according to claim 5, characterized in that the lateral fin (15) is formed on a reinforcing blade (10).

8 - Contact terminal according to any one of claims 2 to 7, characterized in that the bottom and the ceiling have a front part cantilevered, opposite a U-shaped section comprising the folding zone of the blade of contact.