EP3391474B1 - Contact femelle avec lames latérales de maintien pour contact mâle et ensemble de connexion comportant de tels contacts femelle et mâle - Google Patents

Description

The invention relates to the field of electrical connectors and, in particular, electrical connectors for motor vehicles.

The connectors, and in particular, those mounted on internal combustion engines, can be subjected to strong vibrations (for example 60G at 1000Hz). It is therefore important that the male and female contacts of these connectors can maintain an electrical contact that is as low resistive as possible over time, that they are not the source of electric arcs or excessive heating and that they are not the seat of corrosion by friction ("fretting corrosion" according to the English terminology).

• une extrémité d'appariement munie d'une ouverture par laquelle une languette de contact mâle peut être introduite dans la cage, et
• une extrémité de fixation à partir de laquelle le contact se prolonge par une portion de fixation au niveau de laquelle un câble peut être fixé et relié électriquement, par soudure ou sertissage par exemple.

It has been proposed female electrical contacts, such as those described in the document US5681190 and in the document EP0896391A2 , comprising a cage and a sleeve. Such female electrical contacts are intended to be housed in cavities formed in a housing made of a dielectric material. The cage is made from stamped and folded sheet metal. It extends in a longitudinal direction between

• a mating end provided with an opening through which a male contact tab can be introduced into the cage, and
• a fixing end from which the contact is extended by a fixing portion at which a cable can be fixed and connected electrically, by soldering or crimping for example.

The cage has essentially a parallelepipedal shape open at each of the mating and fixing ends, to form a tube with four walls. It therefore comprises a lower wall, an upper wall and two side walls extending between the lower and upper walls. These lower, upper and side walls define an internal space suitable for receiving and housing the tongue of a male contact introduced through the opening of the matching end. The upper and lower walls each comprise at least one contact blade, elastic and extending, from the cage towards a free end, transversely with respect to the longitudinal direction.

Furthermore, the sleeve envelops, from the outside of the cage, at least partially the lower, upper and side walls.

It may be advantageous to be able to use this type of female contact with male contacts of various shapes and sizes, without having to design and manufacture a suitable and adjusted female contact for each male contact shape or size. For example, in the case of male contact with a tongue of flattened shape, the contact blades exert pressure on the main faces of the tongue (essentially parallel to the upper and lower walls of the cage), to establish between them a electric contact. However, the tongue can be caused under the effect of vibrations to move and oscillate between the contact blades, in a plane parallel to the lower and upper walls. Such movements can be the cause of a degradation in the quality of the electrical contact between the male and female contacts thus connected.

An object of the invention is to at least partially overcome this problem and to increase the persistence over time of a good quality of contact between the male and female contacts.

To this end, according to claim 1, a female electrical contact of the type of that described above is produced, with a sleeve, in which at least one of the side walls comprises at least one retaining blade. This retaining blade is elastic and cut in a side wall. It remains attached to the side wall in which it is cut at a junction. This junction is closer to the mating end than to the attachment end. The retaining blade extends from the junction to a free end located closer to the attachment end than to the mating end. The free end protrudes into the internal space. The contact comprises a sleeve enveloping, through the outside of the cage, at least partially the lower, upper and side walls. Each retaining blade has a pressure zone bearing on the sleeve when a male contact tab is housed in the cage.

Thanks to these arrangements, each lateral retaining blade cooperates elastically with an edge of the tongue of the male contact, in order to limit its movements in the female contact in which it is housed. For example, each retaining strip can cooperate with an edge (essentially perpendicular to the main faces) of the tab of the male contact, in order to limit, in the cage, its movements parallel to the lower and upper walls.

• le manchon et/ou la cage comporte deux rampes, chacune repliée vers l'intérieur et/ou l'extérieur de la cage ; par exemple, ces deux rampes sont repliées vers les parois latérales et l'espace interne de la cage, au niveau de l'extrémité d'appariement ce cette dernière ;
• les lames de contact correspondant aux parois supérieure et inférieure comportent, au niveau de leur extrémité libre, une arête entre deux surfaces formant un angle aigu avec un plan parallèle aux parois inférieure et supérieure ;
• les lames de contact correspondant aux parois supérieure et inférieure sont liées à la cage au niveau des parois latérales ;
• la cage est intégralement formée d'une seule pièce ;
• la paroi supérieure de la cage comporte une ligne de jonction entre deux bords d'un flan replié ; et
• la ligne de jonction est au moins partiellement recouverte d'une portion continue du manchon s'étendant au-dessus et parallèlement à la paroi supérieure de la cage et repliée de part et d'autre de celle-ci parallèlement aux parois latérales.

The female electrical contact according to the invention may also include one or other of the following characteristics considered in isolation or in combination with one or more others:

• the sleeve and / or the cage comprises two ramps, each folded towards the inside and / or the outside of the cage; for example, these two ramps are folded towards the side walls and the internal space of the cage, at the level of the matching end thereof;
• the contact blades corresponding to the upper and lower walls comprise, at their free end, an edge between two surfaces forming an acute angle with a plane parallel to the lower and upper walls;
• the contact blades corresponding to the upper and lower walls are linked to the cage at the level of the side walls;
• the cage is integrally formed in one piece;
• the upper wall of the cage has a junction line between two edges of a folded blank; and
• the junction line is at least partially covered with a continuous portion of the sleeve extending above and parallel to the upper wall of the cage and folded over on either side of the latter parallel to the side walls.

According to another aspect, the invention relates to a connection assembly. Such a connection assembly can for example comprise an electrical connector and a counter-connector comprising respectively a female electrical contact according to the invention, with two retaining blades, and a male electrical contact having a tab with one dimension, perpendicular to the direction. longitudinal and parallel to the lower and upper walls, less than the corresponding internal dimension of the cage, and greater than the distance between the free ends of the retaining blades (when they are not constrained, before insertion of the tongue into the cage ).

This connection assembly optionally comprises a tongue having the shape in cross section of a flattened parallelepiped, and the retaining blades each bear respectively on an edge of the tongue corresponding to the short side of this parallelepiped.

• la figure 1 représente schématiquement en perspective un ensemble ce connexion comprenant un contact mâle et un contact femelle ;
• la figure 2 représente schématiquement en perspective la cage du contact femelle de la figure 1 ;
• la figure 3 représente schématiquement en perspective, vue essentiellement de face, la cage de la figure 2 ;
• la figure 4 représente schématiquement en perspective et en coupe, vue essentiellement de dessus, la cage des figures 2 et 3 ;
• la figure 5 représente schématiquement en perspective et en coupe, vue essentiellement de dessus, la cage des figures 2 et 3, avec un manchon autour de la cage et une languette de contact mâle inséré dans la cage ;
• les figures 6A et 6B représentent chacune une languette de contact mâle ayant une forme différente de celle insérée dans la cage du contact femelle représenté sur la figure 5 ;
• les figures 7A et 7B représentent en coupe longitudinale une variante de la cage du contact femelle représenté sur les figures 1 à 5, avec une languette de contact mâle insérée dans la cage ; et
• les figures 8A et 8B représentent en coupe longitudinale une autre variante de la cage du contact femelle représenté sur les figures 1 à 5, avec une languette de contact mâle insérée dans la cage.

Other characteristics and advantages of the invention will become apparent on reading the detailed description which follows and on the appended drawings. On these drawings:

• the figure 1 schematically shows in perspective an assembly of this connection comprising a male contact and a female contact;
• the figure 2 schematically represents in perspective the cage of the female contact of the figure 1 ;
• the figure 3 schematically represents in perspective, seen mainly from the front, the cage of the figure 2 ;
• the figure 4 schematically represents in perspective and in section, seen mainly from above, the cage of figures 2 and 3 ;
• the figure 5 schematically represents in perspective and in section, seen mainly from above, the cage of figures 2 and 3 , with a sleeve around the cage and a male contact tab inserted into the cage;
• the figures 6A and 6B each represent a male contact tab having a different shape from that inserted in the cage of the female contact shown in figure 5 ;
• the figures 7A and 7B show in longitudinal section a variant of the cage of the female contact shown in the figures 1 to 5 , with a male contact tab inserted into the cage; and
• the figures 8A and 8B show in longitudinal section another variant of the cage of the female contact shown in the figures 1 to 5 , with a male contact tab inserted into the cage.

In this document the terms “front”, “rear”, “top”, “bottom”, etc. are purely conventional and refer, where appropriate, to the orientations as shown in the figures.

The connection assembly 100 shown in figure 1 comprises a female contact 1 and a male contact 2 (of which only the tongue 3 is shown in the figures). The female contact 1, alone or with other contacts, can be housed in a connector housing (not shown) of electrically insulating material. Likewise, the male contact 2, alone or with other contacts, can be housed in a housing of a counter-connector (not shown) made of electrically insulating material, adapted to mate with the connector comprising the female contact 1. .

The female 1 and male 2 contacts are coupled, or paired, electrically and mechanically by inserting the tab 3 into the cage 4 of the female contact 1, in an insertion direction essentially parallel to the longitudinal direction L of the male 2 and female 1 contacts. .

The female contact 1 also comprises a fixing portion 5 extending the cage 4, towards the rear of the latter, in the longitudinal direction L. The fixing portion 5 is suitable in this case to receive and crimp the end of a cable (not shown). The female contact 1 also includes a protective sleeve 6.

The cage 4 is obtained by stamping and bending a sheet of conductive material (copper or aluminum or an alloy of these metals for example). The sleeve 6 is also obtained by stamping and bending a sheet of conductive material (steel for example).

As shown on figure 2 , the cage 4 has essentially a parallelepipedal shape. It extends longitudinally parallel to the direction L between a matching end 7, towards the front, and a fixing end 8, towards the rear. The cage 4 forms (without taking into account the cutouts in the walls) a tube whose cross section is essentially rectangular. This tube therefore has essentially four walls: a lower wall 9, an upper wall 10 and two side walls 11. It is open at each of its longitudinal ends 7 and 8. On the side of the matching end 7, it has a opening through which the tongue 3 of a male contact 2 can be inserted. The lower 9, upper 10 and side walls 11 thus define an internal space suitable for receiving and accommodating the tongue 3.

For the embodiment described here, the cage 4 is formed in a single piece, by folding, parallel to the longitudinal direction L, a shape cut by stamping and by bringing the edges of the stamping blank, one towards l 'other, substantially at the level of a median junction line 12 of the upper wall 10 of the cage 4. The junction line 12 is partly covered with a continuous portion 24 of the sleeve 6 (see figure 1 ). extending above and parallel to the upper wall 10 of the cage 4. This continuous portion 24 is folded back on either side of the latter parallel to the side walls 11. It helps to prevent the edges of the cage 4 do not deviate.

The upper 12 and lower 9 walls each comprise two elastic contact blades 13 and extending, from the cage 4 towards a free end 14, transversely with respect to the longitudinal direction L. In the embodiment described here, the contact blades 13 corresponding to the upper 10 and lower 9 walls are linked to the cage at the level of the side walls 11. It can be seen that relatively wide cutouts are made around these contact blades 13. Thus, a certain elasticity is imparted to the cage 4 which makes it possible to damp part of the energy of the vibrations and limits any relative displacements between the tongue 3 and the contact blades 13. Thus, this elasticity ensures good resistance to vibrations, at the same time good performance electric.

As shown on figure 3 , the contact blades 13 comprise at their free end 14, an edge 15 between two surfaces forming an acute angle with a plane parallel to the lower 9 and upper walls 10. Each edge 15 is essentially tangent to a straight line parallel to the direction longitudinal L. Each edge 15 thus allows the contact blades 13 to bite into the material constituting the tongue 3, when it is inserted into the cage 4, which thus contributes to establishing the least resistive electrical contact possible between the blades contact 13 and the tongue 3. In addition, each edge 15 makes it possible to better anchor the tongue 3 between the contact blades 13 and to exert on the tongue 3 a frictional force tending to limit as much as possible the relative displacement of the tongue 3 with respect to the cage 4 in a plane parallel to the upper 10 and lower 9 walls.

The side walls 11 each comprise a retaining strip 16, resiliently cut from a side wall to which it remains attached at a junction 17. Each retaining strip 16 therefore extends from a junction 17 towards one end. free 18. Each retaining blade 16 is folded back towards the rear of the cage 4, that is to say towards the fixing end 5, in order to facilitate the insertion of the tongue 3 into the cage 4 from opening corresponding to the matching end 7. As can be seen on the figures 3 and 4 , when no tongue 3 is introduced into the cage 4, the retaining blades 16 extend generally transversely in the internal space of the cage 4, up to possibly almost meet in the center thereof. The length and shape of the retaining blades 16 make it possible to adapt to many shapes of tabs 3, whether these have parallel edges 19, as on the figure 6A or bevelled as on the figure 6B .

Each side wall 11 has a window 20 corresponding to the portion of the cage 4 cut to form a respective retaining blade 16.

Each retaining blade 16 has, in longitudinal section, parallel to the lower 9 and upper 10 walls, an “S” shape. As shown on figure 5 , a portion of this "S" shape is intended to come into contact with a longitudinal edge 19 of the tongue 3, when the latter is introduced into the cage4. Another portion of this "S" shape is intended to come into contact with the internal face of the sleeve 6. This last portion of the "S" shape forms a pressure zone bearing on the sleeve 6 when a male contact tab 3 2 is housed in cage 4. Thus, not only do retaining blades 16 guide and hold tab 3 in cage 4, but they limit, on the one hand, transverse movements (in a parallel plane to the upper 10 and lower walls 9) of the tab 3 relative to the cage 4 and, on the other hand, the movements of the cage 4 relative to the sleeve 6. In addition, the pressure of the retaining blades 16 on the internal face of the sleeve 6 increases the force exerted by the blades retainer 16 on tab 3, thus contributing to better retention of tab 3 in cage 4.

As can be seen on the figure 5 in particular, the sleeve 6 comprises two ramps 21. Each ramp 21 is folded towards the internal space of the cage 4 at its mating end 7. They guide the tongue 3 during its introduction into the cage 4. These ramps 21 make it possible to attach the sleeve 6 in the cage 4 and to block the movement of the cage 4 in the sleeve 6, in the longitudinal direction L. In addition, these ramps 21 can each form a support point also contributing to limit the transverse displacement (in a plane parallel to the upper 10 and lower 9 walls) of the tongue 3 with respect to the cage 4.

The sleeve 6 also comprises, on its internal face, ribs 22 interfering with the external surface of the side walls 11 of the cage 4, and also contributing to limit the transverse displacement (in a plane parallel to the upper walls 10 and lower 9) of the tab 3 in relation to the cage 4.

Thanks to the retaining blades 16, it is possible to reduce the transverse relative displacements of the tongue 3 in the cage 4 to 0.8 μm or less. For this specific example, the average tongue width is approximately 1.2mm, and the cage width is 1.8mm.

Variants of the previous embodiment are described below in relation to the figures 7A, 7B, 8A and 8B .

The variant of figures 7A and 7B , differs from the previous one essentially in that each retaining strip 16 is folded back, substantially to half its length, by bringing its free end 18 through the window so that the latter is in contact with the internal surface of the sleeve 6 and build on it. The curved portion (substantially in its middle) of each retaining blade 16 comes into contact with a longitudinal edge 19 of the tongue 3 when the latter is introduced into the cage 4. This shape may possibly contribute to giving more rigidity to the holding blades 16, compared to the previous embodiment.

The variant of figures 8A and 8B , differs from the previous ones essentially in that each retaining blade 16 bears on the internal surface of the sleeve 6 by its free end 18 instead of a curved portion. The free end 18 rests on the internal surface of the sleeve 6 at the level of an edge 23 biting into the material constituting the sleeve 6 and creating thus increased friction of the retaining blade 16 on the inner surface of the sleeve 6 when the tongue 3 tends to move transversely in a plane parallel to the upper 10 and lower 9 walls.

In general, the female contact according to the invention can, thanks to the elasticity of the side blade (s), make it possible to accommodate several shapes and sizes of tabs 3 while retaining, or even by improving the performance when the female 1 and male 2 contacts are subjected to vibrations.

Optionally, if the female contact is not surrounded by a sleeve, and the female contact consists of a single piece, what has just been described above in relation to the sleeve 6 can be transposed to the surfaces internal of a box in which the female contact 1 is housed.

Claims (9)

1. Female electrical contact (1) comprising a cage (4) extending in a longitudinal direction between

   - a mating end (7) provided with an opening through which a tongue (3) of a male contact (2) can be inserted into the cage (4),

   - a securing end (8) from which the female contact (1) extends in the form of a securing portion (5) to which a cable may be secured and electrically connected,

   the cage (4) comprises a bottom wall (9), a top wall (10) and two side walls (11) extending between the bottom wall (9) and top wall (10), said bottom wall (9), top wall (10) and side walls (11) delimiting an internal space suitable for receiving and housing the tongue (3) of the male contact (2) inserted through the opening, the top wall (10) and bottom wall (9) each comprising at least one contact blade (13), which is elastic and extends, from the cage (4) towards a free end (14), transversely with respect to the longitudinal direction (L),
   characterized in that at least one of the side walls (11) has at least one retaining blade (16) which is elastic and cut into a side wall (11) to which it remains attached at a junction (17) which is closer to the mating end (7) than to the securing end (8), and which extends from the junction (17) towards a free end (18) located closer to the securing end (8) than to the mating end (7), the free end (18) protruding into the internal space;
   and in that the female electrical contact comprises a sleeve (6) which surrounds the bottom wall (9), top wall (10) and side walls (11), at least partially, on the outside of the cage (4), each retaining blade (16) having a pressure zone bearing on the sleeve (6) when a tongue (3) of the male contact (2) is housed in the cage (4).
2. Contact according to Claim 1, wherein the sleeve (6) has two ramps (21), each bent towards the side walls (11) and the internal space of the cage (4), at the mating end (7) thereof.
3. Contact according to either of the preceding claims, wherein the contact blades (13) corresponding to the top wall (10) and bottom wall (9) have, at their free end (14), a ridge (15) between two surfaces forming an acute angle with a plane parallel to the bottom wall (9) and top wall (10).
4. Contact according to one of the preceding claims, wherein the contact blades (13) corresponding to the top wall (10) and bottom wall (9) are connected to the cage (4) at the side walls (11).
5. Contact according to one of the preceding claims, wherein the cage (4) is integrally formed in one piece.
6. Contact according to one of the preceding claims, wherein the top wall (10) of the cage (4) has a junction line (12) between two edges of a bent blank.
7. Contact according to Claim 6, wherein the junction line (12) is at least partially covered by a continuous portion (24) of the sleeve extending above and parallel to the top wall (10) of the cage (4) and bent, on either side thereof, parallel to the side walls (11).
8. Connection assembly having a female electrical contact (1) according to one of the preceding claims, having two retaining blades (16) and a male electrical contact (2) having a tongue (3) with a dimension, perpendicular to the longitudinal direction (L) and parallel to the bottom wall (9) and top wall (10), less than the corresponding internal dimension of the cage (4), and greater than the spacing between the free ends (18) of the retaining blades (16).
9. Connection assembly according to Claim 8, wherein the tongue (3) has a cross-sectional shape of a flattened parallelepiped, and the retaining blades (16) each bear respectively on a short side of this parallelepiped.

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