EP0011031A1 - Connector for joining without stripping electrical conductor cables, and crimping tools for such a connector - Google Patents

Abstract

A connector providing the joining, without stripping, of electrical conductor cables, and tools for crimping such a connector onto cables. The tool comprising two shapes or jaws, either each made up of two inclined planes, or having corresponding undulations which engage during crimping, crimps the connector, comprising a tube (1), on the inside lateral surface of which is disposed a rasp (2) whose barbs (3) are identical, for holding onto the conductors (12 and 13) received in the tube (1), so that barbs (3) of the rasp (2) traverse the sheaths and penetrate into the cores of the conductors (12 and 13) in the central part (14) of the tube (1), where the barbs (3) are most closely spaced, whilst the barbs (3) penetrate into the sheaths at the ends (15 and 16) of the tube (1), where the barbs (3) are least closely spaced, the gradual penetration of the barbs (3) into the cables (12 and 17) being ensured by the shape of the jaws of the tool. <IMAGE>

Description

The present invention relates to a connector for ensuring a connection without stripping of electrically conductive cables, as well as crimping tools for such a connector.

Numerous embodiments of so-called "self-stripping" connectors are already known, which can be used manually, without any particular tool, to ensure the connection of at least two ends of electrically conductive cables.

In US Pat. No. 2,534,881, the ends of the conducting cables are introduced between the free ends of two branches joined by their other end to constitute an elastic clamp, made of conducting metal, and of generally conical shape, at least one of the branches of which carries , at its free end, a row of teeth or a cutting blade, arranged transversely on the longitudinal axis of the pliers. The bringing together of the branches causes the teeth or the blade to cross or cut the insulating sheath of the conductors, and bring the latter into contact with the core of the conductors. Then each clamp is introduced into a corresponding generally conical housing of an insulating cap, maintaining the connection, until a pin, a bead or a shoulder of each branch is placed in a groove or behind a shoulder of the cap to prevent the clamp from coming out of the cap. The ends of the conductors can be inserted side by side in a single clamp, or each in one of two clamps then placed back-to-back. back in a cap having two conical housings opening into each other by their top.

These connectors have the disadvantage that shearing of the conductors is possible because the teeth or the cutting blade penetrate in the same transverse plane of the conductors. In addition, the mechanical strength of the connection is poor, because an axial traction on the conductors can open the teeth, and vibrations can cause the clamp to come out of the cap. Indeed, the tightening of the clamps is maximum just before the arrival of the pins or the beads of the clamp in the grooves of the cap or just before the passage of the shoulders of the clamp behind the shoulders of the cap, then there is a slight shrinking branches. The teeth thus provide deeper holes in the conductors than those necessary in the connection position. Therefore, when the connector is subjected to strong vibrations, the teeth can easily sink into the deeper holes than necessary, and the clamp can come out of the cap.

In the connector versions with two clamps, good continuity of the electrical connection is not ensured, on the one hand between the conductor and the clamp, on the other hand, between the two clamps, because the teeth occupy a only axial position with respect to the cap, the conical walls of which ensure the application of the arms of the clamp and of the teeth on the cable, and that the clamps also occupy a single back-to-back position in the same cap. Strict geometrical conditions must therefore be respected so that the two peaks of the clamps touch each other simultaneously while each clamp is blocked in the cap by its pawns, beads or shoulders, and that the teeth are sufficiently driven into the conductors.

We can therefore connect only conductors whose diameters are equal or close, and any deformation of the insulating cap can remove the contact between the two clamps.

In US Patent 2,725,545, the ends of the conductors, each passing through the central passage of an elastic sleeve, of conical outer shape, and disposed in the conical housing of a half-olive, are introduced into blind bores practiced on the and on the other side of an insulating block, passing between two forks constituted by the ends folded towards the center of the connector of elastic conductive strips retained by their central part on the periphery of the insulating block. When the latter is introduced into the half-olives, the forks close on the conductors, from which they pass through the insulating sheath to ensure the electrical connection. This connector also has the drawback of a very small number of contact points between the core of the conductors and the connecting strips, these contact points being moreover located in the same transverse plane, hence a reduction in the resistance of the conductor and poor electrical continuity especially in the case where the conductors are the subject of successive connections. In addition, the structure of this connector is complex, since the latter consists of nine pieces of seven different types, and, on the other hand, the mechanical and electrical connection depends on the quality of the fixing of the two half-olives. one on the other, for example by screwing. In conclusion, connectors of this type are complex, delicate to manufacture, therefore expensive, and their possibilities of use are limited to the connection of conductors of fairly similar diameters.

By German patent 1,280,952 and French patents 1,441,209, 2,003,365 and 2,025,232, there are known self-stripping connectors, which are crimped on the ends of conductors by means of a tool, to achieve splices.

These connectors consist essentially of three elements of generally cylindrical shape with oval section, including an inner sleeve with a thin wall, made of a hard and elastic conductive material, in which are made, ie a succession of transverse lines, with respect to the axis. of the sleeve, of generally triangular teeth directed towards the inside of the sleeve, that is to say a network of parallel rows of pins, identical to each other, arranged in a staggered network, and having a main direction perpendicular to the surface of the sleeve , which is thus presented in the form of a rasp. This rasp is received on the inner lateral surface of an outer sleeve, with a thick wall, made of a conductive and deformable metallic material, one end of which is open and the other of which may be either also open or of ogival shape and closed, this external sleeve itself being received in an external insulating jacket, of a heat-shrinkable material, which is open at the end corresponding to the open end of the deformable external sleeve, to allow insertion by this single side ends to connect conductors, and the other end of which is narrowed and possibly closed.

Crimping is obtained by means of a tool, the pressure jaws or jaws of which consist of two planes inclined one on the other, pressing at their ends closer together against a stop, so that the crimped connector takes a shape with a conical longitudinal section, and has a progressive depression of the teeth or pins in the sheaths then in the conductors' cores by considering the conical section from the base to the top of the cone.

These connectors, of a relatively simplified structure, since comprising only three essential elements, have the drawback of being limited, in their possibilities of use, to the production of splices, by connecting ends arranged side by side. side of conductive cables, but they do not make it possible to make end-to-end conductor connections, or branches from at least one uncut cable. Finally, by German patent application No. 2,412,540 and French patent application No. 2,049,809, there are known self-stripping connectors provided with a deformable contact element, of cylindrical and tubular shape before connection, having, on its internal face, projections with sharp edges, produced in the mass of the conductive material constituting the contact element, and coming into contact with the core of at least one conductor, introduced into the contact element, after cutting the insulating sheath of the conductor, to ensure electrical continuity, when the contact element is crimped onto the conductor (s). In French patent application No. 2,049,809, the contact element consists of a part of a connection pin, retained by another part in an insulating connector body, to which only one conductor is connected, one end of which is introduced into the pin.

In German patent application No. 2.412.540, the contact element is a sleeve retained in a heat-shrinkable jacket which defines at one end of the sleeve, an opening for the introduction of the ends of the two conductors to be connected, up to 'when they come into abutment against a shutter retained or defined at the other end of the sleeve by the heat-shrinkable shirt.

These connectors, of simplified structure since comprising only two essential elements, however have the drawbacks that the projections with sharp edges consist of annular ribs or helical threads, so that they constitute cleavers capable of cutting strands of 'a conductive cable with a multi-core core or weakening a conductive cable with a single-core or solid core, and that the conductor (s) to be connected can only be introduced on one side of the connector. In conclusion, the use of such connectors is limited to making splices, and reduces the mechanical resistance and the electrical continuity of the connection.

By the present invention, it is proposed to remedy the various drawbacks presented by known connectors, by means of a connector of a very simple structure, comprising only a small number of components, each of these components being itself easy and inexpensive to manufacture, the crimping operation being carried out safely and easily using simple tools, to obtain good mechanical strength and good fatigue strength of the connection, as well as good continuity of the electrical connection, without damage to the conductors, in particular, for their core, whether it is multi-wire or single-wire, even if these conductors have very appreciably different diameters, the connector finally having to make it possible to make both splices, between conductive cables whose ends are presented side by side, as well as connections between conductors whose ends are placed end to end, and that branches between at least one uncut conductor passing through the connector right through and conductors one end of which is introduced into the connector.

To this end, the connector according to the invention, intended to ensure the connection without stripping of such electrical conductors, is of the type comprising a cylindrical retaining tube, on the internal lateral surface of which is retained an element in the form of a rasp, made of an electrically conductive material, and made up of parallel rows of pins, identical to each other, arranged in a staggered network, and having a main direction perpendicular to the internal surface of the tube, is characterized in that the tube cylindrical, open at both ends, is of circular internal and external section and of constant thickness, and in that the rasp has a base of also cylindrical shape, of circular section, open at its ends, so as to be able to receive by one and / or the other of its ends of the ends of electrically conductive cables to be connected together and / or at least one electrically conductive cable threaded into the connector which it passes right through. A good anchoring of the conductors in the connector is obtained if the pins have, at the end, two points separated by a groove.

To ensure the connection without stripping of the conductors, the connector according to the invention presented above is crimped onto at least one end inserted into the connector of a conductive cable and / or at least one conductive cable threaded into the connector that '' it crosses right through, the penetration of the pins of the rasp in the sheaths then in the cores of the conductors being doubly progressive and stepped from the ends of the connector towards its central part, symmetrical pins with respect to the longitudinal axis of the tube being the closest to each other and the most deep in the core of the conductors in the central part of the rasp and the tube, and the least close to each other and the least deep in the core and / or in the conductor sheath at both ends of the rasp.

Good retention of the conductive cables in the connector is thus obtained, and numerous points of contact of the conductive rasp with the conductive cores of the cables, which establishes the electrical connection between the latter. The mechanical retention of the cables in the connector will be improved if, in addition, the ends of the retaining tube are crimped onto the sheaths of the conductors.

This is particularly advantageous if the holding tube is made of a deformable non-conductive material, since the conductive rasp is thus pro tégée against any introduction by the ends of the connector of any metal part likely to cause a short-circuit.

To ensure the crimping of such a connector, a tool according to the invention, comprising two symmetrical shapes capable of being brought close to each other, is characterized in that each of the shapes comprises two inclined planes forming a dihedron whose the edge is parallel and is the nearest part of the edge of the dihedron formed by the two inclined planes that includes the other form, so that the crimping of the connector receiving the cables between deu _"- forms, ensures, in a progressive and staged fashion, the penetration of the pins in the sheaths and in the cores of the cables. In addition, if each dihedron is placed between two beads of border of the shapes of the tool, the ends of the tube are crimped holding on the sheaths.

To prevent a certain elastic return of the walls of the connector from possibly being able to develop, after the crimping operation of a connector according to the invention by means of the crimping tool presented above, the invention has for subject a second crimping tool, the relaxation of which, after deformation of the connector, is not followed by an opposite deformation of the connector, by elastic return, and of sufficient amplitude to alter, mechanically and electrically, the quality of connection.

The second crimping tool, comprising two jaws capable of being brought closer to one another, is characterized in that the jaws have corrugations in correspondence and cooperating during ser weaving, with a decreasing profile, the interval between the jaws in their central part being less than what it is at their ends.

The "wave" crimping thus obtained avoids the elastic return of the connector and, moreover, increases the mechanical resistance of the connection. The stepped or progressive depression of the pins in the sheath and the core of the conductors is obtained by the decreasing profile, preferably even gradually decreasing, of the undulations. At least one of the jaws can, moreover, have at least one flat surface between two undulations. Alternatively, the undulations of the two jaws are of complementary shape, and are only provided on the central part of the jaws, at least one end of which is planar, and constitutes with the planar end facing the other jaw, a diverging turned towards the sides of the tool.

• - la figure 1 représente, en partie en coupe axiale, un connecteur avant sertissage,
• - la figure 2 représente une vue de côté d'un outil de sertissage du connecteur selon la figure 1,
• - la figure 3 représente en partie en coupe axiale le connecteur selon la figure 1 après sertissage, au moyen de l'outil selon la figure 2, sur deux câbles de diamètres différents,
• - la figure 4 représente, en cours de sertissage et en coupe longitudinale, un outil dont les deux mors, entre lesquels est disposé un connecteur se-Ion la figure 1, ne présentent que des ondulations,
• - et la figure 5 représente, de manière analogue, les deux mors d'un autre outil, sur lesquels des parties planes sont associées à des ondulations. En référence à la figure 1, le connecteur comprend un tube de maintien 1, cylindrique, ouvert à ses deux extrémités, de section interne et externe circulaire, et d'épaisseur sensiblement constante. Un tel tube de maintien 13 est facile à fabriquer à partir d'un feuillard de matériau isolant ou conducteur découpé puis roulé ou d'un tube extrudé puis coupé à la longueur voulue. A l'intérieur du tube 1 est reçue une râpe 2, présentant des picots 3 de forme et de taille identiques, qui s'étendent selon une direction principale perpendiculaire à la surface interne du tube 1. La râpe 2, réalisée en un matériau électriquement conducteur, tel qu'un métal, par exemple à partir d'une tôle, percée au moyen d'une matrice de poinçons repoussant des petites portions de tôle pour constituer les picots, puis découpée et roulée, présente une base de forme également cylindrique, à section circulaire, ouverte à ses extrémités, qui recouvre toute la surface latérale interne du tube 1, à l'exception de deux petites couronnes 4 aux extrémités. De façon en soi connue, la râpe 2 comporte des rangs parallèles de picots 3 disposés selon un réseau en quinconce. Si le tube 1 est réalisé en un matériau isolant, les couronnes 4 assurent une protection de la râpe conductrice 2.

The present invention will be better understood using the specific examples of embodiment of a connector and crimping tools which will be described, without implied limitation, with reference to the appended figures in which:

• FIG. 1 represents, partly in axial section, a connector before crimping,
• FIG. 2 represents a side view of a crimping tool for the connector according to FIG. 1,
• FIG. 3 partially shows in axial section the connector according to FIG. 1 after crimping, by means of the tool according to FIG. 2, on two cables of different diameters,
• - Figure 4 shows, during crimping and in longitudinal section, a tool with two jaws, between which is disposed a connector Ion Figure 1, only show ripples,
• - And Figure 5 shows, analogously, the two jaws of another tool, on which flat parts are associated with corrugations. With reference to FIG. 1, the connector comprises a cylindrical holding tube 1, open at its two ends, of circular internal and external section, and of substantially constant thickness. Such a retaining tube 13 is easy to manufacture from a strip of insulating or conducting material cut then rolled or from an extruded tube then cut to the desired length. Inside the tube 1 is received a rasp 2, having pins 3 of identical shape and size, which extend in a main direction perpendicular to the internal surface of the tube 1. The rasp 2, made of a material electrically conductor, such as a metal, for example from a sheet, pierced by means of a matrix of punches pushing small portions of sheet to form the pins, then cut and rolled, has a base of also cylindrical shape, of circular section, open at its ends, which covers the entire internal lateral surface of the tube 1, with the exception of two small crowns 4 at the ends. In a manner known per se, the rasp 2 comprises parallel rows of pins 3 arranged in a staggered network. If the tube 1 is made of an insulating material, the rings 4 provide protection for the conductive rasp 2.

The crimping tool shown in Figure 2, which can be manual, and be in the form of pliers, or be mounted on a press with manual or automatic control, comprises two forms or symmetrical jaws 5 and 6 which can be brought together.

Each of the forms 5 and 6 comprises two inclined planes 7 and 8, forming a dihedron whose edge 9 is parallel to the edge 9 of the other dihedron, and constitutes the part of the dihedron closest to the other dihedron, each of the dihedrons being disposed between two beads 10 and 11 forming an edge of the shapes 5 and 6 on each side of the tool.

After having introduced, for example into one end of the holding tube 1, the end to be connected with a cable, the end of another cable being introduced into the other end of the tube 1, and after having arranged the tube 1, receiving the ends of the cables, between the two forms 5 and 6 of the tool, the connector can be crimped onto the cables, bringing forms 5 and 6 closer to one another. The connector thus obtained, as shown in Figure 3, ensures the retention, in the holding tube 1, of a small diameter cable 12, electrically connected to a large diameter cable 13, by the pins 3 of the rasp which, thanks to the inclined planes 7 and 8 guaranteeing a progressive penetration of the pins 3 in the sheaths and the cores of the cables 12 and 13 during crimping, pass through the two sheaths and are embedded in the cores of the conductors in the central part 14 of the tube 1, where the pins 3, symmetrical with respect to the axis of the tube 1, are closest to each other, which defines an electrical connection without stripping the cables, without damaging their core, because the numerous points of contact are distributed axially along the conductors, while at the ends 15 and 16 of the tube 1, where the pins 3 symmetrical with respect to the axis of the tube 1 are the least close to each other, the pins 3 of the end 15 penetrate into the sheath of the cable 13 of large diameter and improve its retention in the tube 1, the sheath of the small diameter cable being only slightly or not penetrated by the pins 3 of the end 16. In addition, thanks to the beads 10 and 11 of the shapes 5 and 6 of the tool, the parts 4 of the holding tube 1 are crimped onto the sheaths of the cables 12 and 13 and further improve the mechanical strength of the connection.

The penetration and incrustation of the p'cots 3 in the sheaths and the cores of the conductors 12 and 13 will be more or less facilitated, depending on the particular profile presented by the pins 3. According to a particularly interesting embodiment, the pins 3 have , at the end, two points 17 separated by a furrow. This profile gives good results of incrustation and penetration, without causing too marked cutting of the sheaths or shearing the conductive cores, due to the staggered arrangement of the pins 3.

The connector thus crimped has a shape such that an elastic return of its walls can possibly develop. To avoid this drawback, tools can be used according to FIGS. 4 and 5. With reference to FIG. 4, the tool comprises two jaws 17 and 18, capable of being brought towards and away from each other. Each of the jaws 17 and 18 has corrugations 19 and 20 respectively, which are in correspondence and cooperating during crimping to give the connector, initially of cylindrical external shape, a shape wavy or "in waves". The undulations 19 and 20 have a gradually decreasing profile, that is to say that the interval separating the jaws is minimal in their median plane and gradually increases towards their ends. In this way, the pins 3 of the rasp 2, received inside the holding tube 1, are brought to gradually penetrate the sheaths and the cores of the electrically conductive cables 12, of smaller diameter, and 13, larger diameter, introduced into the _' connector, for example each by one of the ends of the latter, during crimping.

In the central part of the tube 1, the pins 3 pass through the sheaths of the two conductive cables 12 and 13 and are embedded in their cores, since the pins 3 initially arranged symmetrically with respect to the axis of the tube 1 are the closest from each other, which defines an electrical connection without stripping the cables 12 and 13, while towards the ends of the tube 1, where the pins 3 are, in the section plane, the most distant from each other, the pins 3 penetrate only into the insulating sheaths of the conductive cables 12 and 13, which ensures the retention of the latter in the connector. The mechanical strength of the connection is improved by pinching the cables 12 and 13 due to the "wave" shape given to the connector by the corrugations 19 and 20 of the two jaws 17 and 18.

This effect is added to that which consists in preventing any elastic return of notable amplitude of the tube 1 and of the rasp 2 after deformation, when the jaws 17 and 18 have been released, which ensures good resistance to fatigue of the connection. mechanical and electrical plug provided by the connector.

The tool, shown in FIG. 5, comprises two jaws 21 and 22 having, in their central part, corrugations 23, 24 and 25, 26, of complementary shapes, separated on each jaw, by a flat surface 27 and 28. The ends 29 and 30 of the jaw 21 are planar and parallel to the axis of the tube 1 when the latter is not deformed, and constitute with the ends 31 and 32 opposite the other jaw 22 diverging facing the sides of the tool, the ends 31 and 32 of the jaw 22 being either either flat and inclined on the axis of the tube 21 before deformation, or wavy. However, it is also possible to provide that the planar ends 29 and 30 are one and / or the other inclined on the axis of the tube 1, just as the ends 29 and 32 can be planar and parallel to this axis. , while the ends 30 and 31 are flat and inclined on this axis.

This tool, used in the same way as that shown in Figure 4, provides the same advantages.

By their simple structure, the tools according to the invention will advantageously be used to crimp connectors according to the invention in all cases where it is wished to quickly proceed to the connection of conductive cables or to carry out branches or splices on these without having to strip them off.

It should be noted that at least two conductive cables are received in the connector before crimping, either that the two cables are introduced by the same end of the tube, or that each of the cables is alone to be introduced by one extremities. It is also possible to connect a given number of conductive cables, introduced by one end of the tube to another given number of conductive cables, introduced by the other end of the tube, or alternatively to make branches by connecting with one or more conductors not sectioned. , passing through the connector before crimping, the end of one or more other conductors, introduced into the tube by one or the other of its ends, by means of connectors according to the invention.

Claims (10)

1 / Connector intended to ensure the connection without stripping of electrically conductive cables (12,13) which may have different diameters, comprising a cylindrical retaining tube (1), on the internal lateral surface of which an element in the form of a material is retained of a rasp (2), made of an electrically conductive material, and consisting of parallel rows of pins (3) identical to each other, arranged in a staggered network, and having a main direction perpendicular to the internal surface of the tube ( 1) characterized in that the cylindrical tube (1), open at its two ends, is of circular internal and external section and of constant thickness, and in that the rasp (2) has a base of also cylindrical shape, with circular section, open at its ends, so as to be able to receive by one and / or by the other of its ends ends of electrically conductive cables (12, 13) to be connected together and / or to at least one cable driver electric threaded into the connector it crosses right through. 2 / connector according to claim 1, characterized in that the pins (3) have, at the end, two points (17) separated by a groove. 3 / Connector ensuring the connection without stripping of at least two electrically conductive cables (12,13), each consisting of a conductive core surrounded by an insulating protective sheath, characterized in that it is obtained by crimping a connector according to one of claims 1 and 2 on at least one end inserted into the connector of a conductive cable (12,13) and / or at least one conductive cable threaded into the connector which it passes right through, the penetration of the pins (3) of the rasp (2) in the sheaths then in the cores of the conductors (12 , 13) being doubly progressive and stepped from the ends (15,16) of the connector towards its central part (14), symmetrical pins (3) with respect to the longitudinal axis of the tube being the closest to each other and the deeper into the core of the conductors (12,13) in the central part (14) of the rasp (2) and the tube (1) and the less close to each other and the less sunk into the core and / or in the sheath of the conductors (12,13) at the two ends (15,16) of the rasp (2). 4 / connector according to claim 3, characterized in that the ends (4) of the holding tube (1) are crimped on the sheaths of the conductive cables (12,13). 5 / connector crimping tool according to one of claims 1 and 2, comprising two symmetrical shapes (5,6) capable of being brought close to each other, characterized in that each comprises two inclined planes (7 , 8) forming a dihedron whose edge (9) is parallel, and constitutes the part closest to the edge (9) of the dihedron constituted by the two inclined planes (7,8) that the other shape includes. 6 / Crimping tool according to claim 5, characterized in that each dihedral is arranged between two beads (10,11) of the edge of the forms (5,6). 7 / Connector crimping tool according to one of the preceding claims 1 to 2, comprising two jaws (17,18,21,22)., capable of being brought closer to each other, characterized in that the jaws have undulations (19,20, 23,24,25,26) in correspondence and cooperating during crimping, with a decreasing profile, the interval between the jaws (17,18,21,22) in their central part being less than it is at their ends. 8 / Tool according to claim 7, characterized in that the corrugations (23,24,25,26) are of complementary shape. 9 / Tool according to one of claims 7 and 8, characterized in that at least one of the jaws (21,22) has at least one flat surface (27, 28) between two corrugations (23,24 and 25, 26). 10 / Tool according to one of claims 7 to 9, characterized in that the corrugations (23,24, 25,26) are provided on the central part of the jaws (21,22), at least one end of which is planar ( 29, 30) and constitutes with the opposite end (31,32) on the other jaw, a diverging part facing the sides of the tool.

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