EP1771923B1 - Tool and method for crimping a contact onto a cable - Google Patents

Description

The invention relates to a tool crimping a contact on the end of an electric cable. It also relates to a method of crimping a contact on the end of an electric cable.

Most modern aircraft have a large number of electrical cables. These cables generally consist of a conductive copper core surrounded by an electrically insulating sheath. Conventionally, the ends of the copper cables are stripped and a connector contact is crimped on the conductive core of each of said ends, allowing the electrical connection of the cables. Given the number and length of cables needed to build an aircraft, the mass of these cables can reach several hundred kilograms on a modern civilian transport aircraft, the equivalent of several passengers. In order to improve the performance of aircraft, it is interesting to replace at least part of the copper cables with aluminum cables, lighter than copper cables. Similar to copper cables, an aluminum cable consists of an aluminum conductive core surrounded by an insulating sheath generally made of plastic.

In order to be able to electrically connect the aluminum cables, it is desirable to place a connector contact at each end of said cables. The use of contacts similar to those used for copper cables is unsatisfactory because these contacts are crimped only on the conductive core which can, therefore, be at least partially in contact with the ambient air. Aluminum is a metal that oxidizes much more rapidly than copper in contact with air. In addition, the aluminum oxide forms an electrically insulating layer which therefore risks to oppose the electrical continuity between the conductor core of the cable and said connector contact crimped on its end.

One known way to solve this problem is to use a contact having a first portion capable of being crimped on the conductive core and a second portion adapted to be crimped airtight on the insulating sheath. So, once the contact crimped on the end of the cable aluminum, the conductive core is no longer in contact with the ambient air, which avoids the aforementioned problems of oxidation. Licences FR2.686.459 , FR2.708.150 and FR2.710.788 relate to methods of connecting a cable to a contact and a crimping tool of such a contact suitable for aluminum cables. However, they require the use of contacts having a partially frustoconical outer surface and are therefore not suitable for contacts of cylindrical outer shape at least in the parts to be crimped.

Licences FR1.240.942 and US2.985.047 are relative to a tool allowing, in one embodiment, to crimp a contact both on the conductive core of the cable and on a non-stripped portion of its insulating sheath. This tool comprises articulated jaw blades forming two stages operated simultaneously, one ensuring crimping of the contact on the conductive core and the other ensuring crimping of the contact on the insulating sheath. However, the part of the contact crimped on the insulating sheath has a section whose perimeter comprises three flat faces arranged substantially in a triangle, interconnected by concave portions. The shape of this section is not suitable for connector contacts used in particular in aeronautics because the tools for insertion and extraction of said contacts in these connectors require that the section of the contacts crimped on the insulating sheath is substantially elliptical and preferably circular . In addition, the best airtightness of the crimping of the contact on the insulating sheath is still obtained with a section of the contacts crimped on the substantially elliptical and preferably circular insulating sheath. As for him, crimping said contact on the conductive core should preferably have a section with concave portions distributed over its perimeter in order to obtain good mechanical tensile strength characteristics and good electrical connection characteristics. It must be performed substantially simultaneously with the crimping of said contact on the insulating sheath in order firstly to obtain the best characteristics of airtightness and protection against oxidation and secondly to guarantee the repeatability. the distance between the crimping on the conductive core and the crimping on the insulating sheath.

The patent US3.713.322 is relative to a tool for crimping a contact in a substantially circular section. However, this tool does not allows only one crimping at a time and is therefore not suitable for crimping a connector contact on an aluminum cable.

Patent applications US2004 / 072378 and WO2004 / 021523 (considered to be the closest state of the art) describe a tool having two crimping stages and making it possible to crimp a contact both on the conductive core of the cable and on the insulating sheath of this cable, substantially simultaneously. However, particularly because of the juxtaposition of two crimping stages, such a tool requires significant effort on the clamping handles. These efforts are all the more important as the diameter of the cable is high. They are particularly troublesome when returning the tool to the rest position at the end of crimping. In addition, such forces can cause rapid wear of some parts of the tool.

• un premier étage pour sertir une première partie dudit contact sur l'âme conductrice du câble ;
• un second étage pour sertir une seconde partie dudit contact sur la gaine isolante du câble ; et
• des moyens pour actionner lesdits premier étage et second étage de façon sensiblement simultanée ;

dans lequel :

• lesdits premier étage et second étage comportent des éléments de sertissage aptes à être déplacés relativement au contact à sertir, lors du sertissage ;
• au moins un desdits premier étage et second étage comporte une came coopérant avec les éléments de sertissage de l'étage considéré pour les déplacer de façon à sertir le contact, lors du sertissage ;

cet outil étant en outre remarquable en ce qu'au moins un élément rotatif est disposé entre au moins un desdits éléments de sertissage et ladite came, cet élément rotatif pouvant occuper au moins deux positions par rapport à l'élément de sertissage considéré telles que lorsque cet élément rotatif est en contact à la fois avec cet élément de sertissage et avec ladite came, la distance entre d'une part ladite came et d'autre part une extrémité de cet élément de sertissage apte à toucher ledit contact pour le sertir est différente dans lesdites au moins deux positions.These problems are solved at least partially according to the invention by a crimping tool of a contact on the end of a cable, said cable end having a stripped portion where a conductive core of the cable is stripped and an isolated part. wherein said conductive core is covered by an insulating sheath, said contact comprising a hole coaxial with the longitudinal axis of said contact adapted to receive both said stripped portion and said insulated portion of the cable end, said crimping tool comprising:

• a first stage for crimping a first portion of said contact on the conductive core of the cable;
• a second stage for crimping a second portion of said contact on the insulating sheath of the cable; and
• means for actuating said first stage and second stage substantially simultaneously;

in which :

• said first stage and second stage comprise crimping elements able to be displaced relative to the crimp contact during crimping;
• at least one of said first stage and second stage comprises a cam cooperating with the crimping elements of the stage considered to move them so as to crimp the contact during crimping;

this tool being furthermore remarkable in that at least one rotary element is disposed between at least one of said crimping elements and said cam, this rotary element being able to occupy at least two positions with respect to the crimping element in question such as when this rotating element is in contact with both this crimping element and with said cam, the distance between on the one hand said cam and on the other hand an end of this crimping element able to touch said contact to crimp it is different in said at least two positions.

Preferably, this tool is designed so that during a displacement of the cam relative to the crimping elements, in a first direction corresponding to a crimping, said rotary element occupies a first position with respect to said crimping element, wherein said distance is maximum, and upon displacement of the cam relative to the crimping elements, in a second direction, inverse of the first direction, said rotary member occupies a second position with respect to said crimping member, wherein said distance is minimal.

Thus, since this distance is minimal when the tool returns to the rest position after crimping, the crimping element considered exerts on the crimped contact a lower effort than the force exerted during crimping, or even no effort. Consequently, the friction resulting from the cooperation between said crimping element and the cam is less when returning the tool to the rest position. This results in a first advantage in that the forces to be applied to the means for actuating the first and second stages are smaller. In addition, another advantage is linked to the fact that this reduction in friction also makes it possible to reduce the wear of the parts considered.

In a preferred embodiment, said second stage comprises means capable of crimping a substantially elliptical section.

In addition, the crimping elements of the first and / or second stages are jaws able to be moved radially to the crimp contact during crimping.

Still according to this preferred embodiment, said cam is rotatably mounted around a jaw support, said cam having a track which cooperates with ends of the jaws to move them radially. to the crimp contact, during crimping, these jaws being slidably mounted in grooves of the jaw support.

This tool thus serves to crimp the contact simultaneously on the conductive core of the cable and on the insulating sheath, the crimping on the insulating sheath having a substantially elliptical or circular section, which allows both a good airtightness and thus a protection against the oxidation of the crimping on the conductive core, as well as a compatibility with the tools of insetion and / or extraction of the contact in the connectors used in particular in aeronautics.

In this preferred embodiment, at least one rotary element is disposed between at least one jaw end and said track, this rotating element being able to occupy at least two positions with respect to the jaw end considered, such that when this rotary element is in contact both with this end of jaws and with said track, the distance between on the one hand said track and on the other hand another end of the jaw able to touch said contact to crimp is different in said at least two positions.

In addition, advantageously, the crimping tool is designed so that during a rotation of the cam around the jaw support in a first direction corresponding to a crimping, said rotary member occupies a first position relative to at said jaw end, wherein said distal is at a maximum, and upon rotation of the cam about the jaw support in a second direction, inverse of the first direction, said rotational member occupies a second position with respect to said end of jaws, wherein said distance is minimal. This makes it possible to reduce the friction forces on the track of the cam when the tool returns to the rest position after crimping.

In a first variant embodiment, said rotary element is a substantially spherical ball.

In a second variant embodiment, said rotary element is a substantially cylindrical roller.

In a particular embodiment of this second variant, said roller is mounted integral with an axis of rotation coaxial with said roller and whose ends can slide in slides secured to said jaw end.

Advantageously, said track of the cam comprises a notch at each position of said track facing each jaw which is associated with a rotary member when said cam is at the end of stroke relative to the jaw support, during crimping. These notches facilitate the passage of said rotary members from said first position to said second position at the end of crimping, in order to reduce friction on the track of the cam when the crimping tool returns to its rest position.

In one embodiment of the invention, said track has a shape adapted to allow centrifugal radial movement of the jaws at the end of crimping so as to release these jaws of said contact.

Preferably, the jaw supports are integral with a first handle and the cams are integral with a second handle, said first handle and second handle being common to the first stage and the second stage.

• les mors du premier groupe ont des extrémités aptes à toucher le contact à sertir dont la forme correspond sensiblement à un plan dont l'orientation est sensiblement tangente à ce contact lors du sertissage ;
• les mors du second groupe ont des extrémités aptes à toucher le contact à sertir dont la forme concave correspond sensiblement à un arc de cylindre plus petit qu'un demi-cylindre ;
• les deux mors du premier groupe sont disposés diamétralement opposés de part et d'autre d'un trou du support de mors apte à recevoir le contact à sertir ;
• les deux mors du second groupe sont disposés diamétralement opposés de part et d'autre dudit trou du support de mors apte à recevoir le contact à sertir ;
• les mors du second groupe sont orientés selon un angle sensiblement égal à 90 degrés par rapport aux mors du premier groupe.

More preferably, the second stage comprises two groups of two jaws such as:

• the jaws of the first group have ends capable of touching the crimp contact whose shape substantially corresponds to a plane whose orientation is substantially tangent to this contact during crimping;
• the jaws of the second group have ends capable of touching the crimp contact whose concave shape corresponds substantially to a cylinder arc smaller than a half-cylinder;
• the two jaws of the first group are arranged diametrically opposite on either side of a hole of the jaw support adapted to receive the crimp contact;
• the two jaws of the second group are arranged diametrically opposite on either side of said hole of the jaw support adapted to receive the crimp contact;
• the jaws of the second group are oriented at an angle substantially equal to 90 degrees relative to the jaws of the first group.

This embodiment of the second stage makes it possible to crimp the contact on the insulating sheath of the cable in a substantially oval or circular crimping section which makes it possible to respect the required characteristics. concerning the airtightness and the possibility of using the aforementioned tools for inserting and extracting the contacts in the connectors.

Advantageously, said first stage comprises means capable of producing a crimping whose section has concave parts on its perimeter. This makes it possible to obtain a crimping of the contact on the conductive core of the cable having satisfactory characteristics of mechanical tensile strength as well as of electrical connection between the conductive core of the cable and this contact.

• deux mors voisins sont décalés entre eux d'un angle sensiblement égal à 90 degrés ;
• deux mors autres que des mors voisins sont disposés diamétralement opposés de part et d'autre d'un trou du support de mors apte à recevoir le contact à sertir ;
• les extrémités desdits mors aptes à toucher le contact à sertir ont une forme convexe apte à imprimer des déformations concaves dans ce contact lors du sertissage.

In a particular embodiment, the first stage comprises four identical jaws such as:

• two adjacent jaws are offset from each other by an angle substantially equal to 90 degrees;
• two jaws other than neighboring jaws are arranged diametrically opposite on either side of a hole of the jaw support adapted to receive the crimp contact;
• the ends of said jaws able to touch the crimp contact have a convex shape able to print concave deformations in this contact during crimping.

This embodiment of the first stage therefore serves to crimp the contact on the conductive core of the cable by obtaining the required characteristics of electrical connection and mechanical tensile strength.

The invention is however not limited to first and second crimping stages comprising jaws moving radially to the crimp contact.

• on insère ledit contact à la fois dans un premier étage et dans un second étage d'un outil de sertissage tel que décrit ci-dessus disposés de façon à ce que :
  • le premier étage soit face à une première partie dudit contact entourant l'âme conductrice du câble ;
  • le second étage soit face à une seconde partie dudit contact entourant la gaine isolante du câble ;
• on actionne lesdits premier étage et second étage de façon sensiblement simultanée ;
• l'actionnement du second étage comporte deux étapes successives :
  • on actionne deux premiers mors du second étage, diamétralement opposés de part et d'autre du contact à sertir, dont les extrémités touchant ce contact lors du sertissage sont sensiblement planes, jusqu'à déformer ledit contact selon une section sensiblement ovale ;
  • on maintient lesdits premiers mors en position sur le contact et on actionne deux seconds mors du second étage, diamétralement opposés de part et d'autre du contact à sertir et orientés par rapport aux premiers mors d'un angle sensiblement égal à 90 degrés, dont les extrémités touchant ce contact lors du sertissage sont de forme concave correspondant sensiblement à un arc de cylindre plus petit qu'un demi-cylindre, jusqu'à déformer ledit contact selon une section sensiblement circulaire,

ledit procédé étant en outre remarquable en ce qu'en fin de sertissage on relâche au moins partiellement les mors d'au moins un étage, sous l'effet du déplacement d'au moins un élément rotatif coopérant avec une extrémité biseautée d'au moins un desdits mors, de façon à réduire les efforts nécessaires pour ramener l'outil de sertissage à son état de repos.The invention also relates to a method of crimping a contact on the end of a cable, said cable end having a stripped portion where a conductive core of the cable is stripped and an insulated portion where the conductive core is covered by a insulating sheath, said contact comprising a hole coaxial with the longitudinal axis of said contact adapted to receive both said stripped portion and said insulated portion of the cable end, wherein:

• said contact is inserted both in a first stage and in a second stage of a crimping tool as described above arranged so that:
  • the first stage faces a first portion of said contact surrounding the conductive core of the cable;
  • the second stage faces a second portion of said contact surrounding the insulating sheath of the cable;
• said first stage and second stage are actuated substantially simultaneously;
• the actuation of the second stage comprises two successive steps:
  • two first jaws of the second stage are actuated, diametrically opposed on either side of the crimp contact, whose ends touching this contact during crimping are substantially planar, until deforming said contact in a substantially oval section;
  • said first jaws are held in position on the contact and two second jaws of the second stage, diametrically opposed on either side of the crimp contact and oriented with respect to the first jaws, are operated at an angle substantially equal to 90 degrees, of which the ends touching this contact during crimping are of concave shape substantially corresponding to a smaller cylinder arc than a half-cylinder, until deforming said contact in a substantially circular section,

said method being furthermore remarkable in that at the end of crimping the jaws of at least one stage are released at least partially, under the effect of the displacement of at least one rotary element cooperating with a bevelled end of at least one of said jaws, so as to reduce the effort required to return the crimping tool to its rest state.

• La figure 1 est une vue d'ensemble éclatée, en plan, d'un outil de sertissage selon l'invention.
• La figure 2 est une vue de détail d'un support de mors d'un étage de sertissage.
• La figure 3 est une vue en coupe, selon la ligne A-A de la figure 1, d'un outil de sertissage selon l'invention. Pour plus de clarté, les mors des deux étages ne sont pas représentés.
• La figure 4 est une vue en coupe similaire à la figure 3, sur laquelle les mors des deux étages sont représentés.
• La figure 5 représente un étage de sertissage d'un outil selon l'invention, en position de repos.
• La figure 6 représente l'étage de sertissage correspondant à la figure 5, en position de sertissage.
• La figure 7 représente une variante de l'étage de sertissage correspondant aux figures 5 et 6, en position de sertissage.
• La figure 8 est relative à un étage de sertissage selon l'invention et représente, en vue de détail, un élément rotatif situé entre une extrémité d'un mors coulissant dans un support de mors dudit étage de sertissage et une piste d'une came.
• La figure 9a est similaire à la figure 8 et représente un mode préféré de réalisation dans lequel une encoche est prévue dans la piste de la came. La figure 9b représente plus en détail l'élément rotatif et l'extrémité du mors représentés figure 9a.
• Les figures 10a, 10b et 10c représentent un second étage selon l'invention respectivement en position de repos, en cours de sertissage et en fin de sertissage.
• Les figures 11 a et 11 b représentent un mode de réalisation d'un mors d'un premier étage selon l'invention. Sur la figure 11a, le mors est vu dans un plan perpendiculaire à l'axe de rotation du support de mors, comme sur la figure 2. La figure 11b est une vue en coupe selon la ligne B-B de la figure 11a.
• Les figures 12a et 12b représentent un autre mode de réalisation d'un mors d'un premier étage selon l'invention. Sur la figure 12a, le mors est vu dans un plan perpendiculaire à l'axe de rotation du support de mors, comme sur la figure 2. La figure 12b est une vue en coupe selon la ligne C-C de la figure 12a.

The invention will be better understood on reading the description which follows and on examining the appended figures. In these figures, identical references designate similar elements:

• The figure 1 is an exploded overall view, in plan, of a crimping tool according to the invention.
• The figure 2 is a detail view of a jaw support of a crimping stage.
• The figure 3 is a sectional view along line AA of the figure 1 , a crimping tool according to the invention. For clarity, the jaws of the two floors are not represented.
• The figure 4 is a sectional view similar to the figure 3 , on which the jaws of the two stages are represented.
• The figure 5 represents a crimping stage of a tool according to the invention, in the rest position.
• The figure 6 represents the crimping stage corresponding to the figure 5 , in crimping position.
• The figure 7 represents a variant of the crimping stage corresponding to the Figures 5 and 6 , in crimping position.
• The figure 8 relates to a crimping stage according to the invention and represents, in detail, a rotary element located between an end of a sliding jaw in a jaw support of said crimping stage and a track of a cam.
• The figure 9a is similar to the figure 8 and represents a preferred embodiment in which a notch is provided in the track of the cam. The figure 9b represents in more detail the rotary element and the end of the jaw represented figure 9a .
• The Figures 10a, 10b and 10c represent a second stage according to the invention respectively in the rest position, during crimping and at the end of crimping.
• The figures 11 a and 11b show an embodiment of a jaw of a first stage according to the invention. On the figure 11a , the jaw is seen in a plane perpendicular to the axis of rotation of the jaw support, as on the figure 2 . The figure 11b is a sectional view along line BB of the figure 11a .
• The Figures 12a and 12b represent another embodiment of a jaw of a first stage according to the invention. On the figure 12a , the jaw is seen in a plane perpendicular to the axis of rotation of the jaw support, as on the figure 2 . The figure 12b is a sectional view along the line CC of the figure 12a .

The figure 3 represents a crimping tool 1 according to the invention, comprising a first stage and a second stage. The first floor comprises a jaw support 10 of cylindrical shape. A ring-shaped cam 12 is rotatably mounted around said jaw support 10. The inner face of this ring forms a track 16. The jaw support 10 has grooves 14 radial to the axis of said cylindrical jaw support and each adapted to receive a jaw 18, as shown figure 4 . This jaw can slide in the groove 14 corresponding. In the same way, the second stage comprises a jaw support 20 of cylindrical shape. A ring-shaped cam 22 is rotatably mounted around said jaw support 20. The inner face of this ring forms a track 26. The jaw support 20 has grooves 24 radial to the axis of said cylindrical jaw support and each adapted to receive a jaw 28, as shown figure 4 . This jaw can slide in the groove 24 corresponding. The first stage and the second stage are mounted superimposed so that the axes of rotation of the two cams 12 and 22 coincide with each other and with the axes of the jaw supports 10 and 20 of cylindrical shape. The jaw supports 10 and 20 are mounted integral with a first handle 4. The cams 12 and 22 are preferably of cylindrical outer shape and are mounted integral with a second handle 2 of the crimping tool 1. These two handles 2 and 4 cooperate together to ensure the rotational guidance of the cams 12 and 22 around the jaw supports 10 and 20. A coaxial hole 6 of said axes of rotation is provided in the jaw supports 10 and 20 as well as in the handles 2 and 4 to allow insertion of the crimp contact between the jaws 18, 28 of the first and second stages.

On the Figures 3 and 4 the first stage and the second stage are shown with substantially identical dimensions. However, this representation must not be interpreted in a limiting manner, said first stage and second stage may each have different dimensions.

The crimping tool 1 is shown in flat exploded view on the figure 1 . The cam 12 of the first stage is shown integral with the second handle 2. For clarity of the figure, the cam 22 of the second stage is not shown. The jaw support 10 of the first stage is in turn shown integral with the first handle 4. For clarity of the figure, the jaw support 20 of the second stage, also secured to said first handle, is not shown. The jaw support 10 of the first stage is represented in more detail on the figure 2 . It comprises grooves 14 radial to its axis and therefore also radial to the axis of the crimp contact when it is inserted into the hole 6 of the crimping tool. In the preferred embodiment shown in said figure, said jaw support has four grooves 14; these are arranged two by two diametrically opposite with respect to the axis of the jaw support and two adjacent grooves are offset from each other by an angle substantially equal to 90 degrees. Each of said grooves receives a jaw 18 able to slide in this groove. For clarity of the figure, only one of said jaws is shown.

On the figure 5 , the jaw support 10 of the first stage, equipped with four jaws 18, is shown surrounded by the cam 12 in the rest position. The track 16 of this cam is shaped so as to cooperate with ends of the jaws 18 to allow a displacement of said jaws radially to the axis of rotation of the jaw support 10, towards this axis of rotation, when said cam rotates around of the jaw support, in the direction of arrow F, during crimping. As shown on the figure 6 at the end of crimping, the ends of the jaws 18, opposite said ends of said jaws co-operating with the track 16, are thus displaced in the hole 6 to crimp the contact.

As shown on the figure 8 , the ends of the jaws 18 cooperating with the track 16 are bevelled and a rotatable member 30 is disposed between each beveled end and the track 16. The rotary elements 30 are not shown on the Figures 5, 6 and 7 for the clarity of said figures. The beveled end of a jaw 18 is formed so that the distance between this jaw and said track is maximum at the rear of said jaw and minimum at the front, the notions of front and rear being considered relative to the direction of movement, indicated by the arrow F, of the cam 12 (and therefore of the track 16) relative to the jaw support 10 (and thus the jaw 18) during crimping. During a crimping, under the effect of the frictional forces of the rotating element 30 on the track 16, this rotary element is then placed in a first position shown in solid lines on the figure 8 and located at the front of the jaw 18. When returning to the rest position of the crimping tool after crimping, the cam 12 is moved in the opposite direction to the crimping direction indicated by the arrow F. Under the effect of forces of friction of the rotary member 30 on the track 16, this rotating element is then placed in a second position shown in dashed line on the figure 8 and located at the front of the jaw 18 during said return to the idle state; this second position is therefore located at the rear of the jaw 18 when considering a displacement of the cam 12 (and therefore the track 16) relative to the jaw support 10 (and thus the jaw 18) in the direction of the arrow F during crimping. In this way, the distance between the track 16 and the end of the jaw 18 able to touch the crimp contact is maximum during crimping and minimum when returning to the rest position. This is very advantageous because the forces due to the friction on the track 16 are considerably reduced when returning to the rest position with respect to what they would be if an end of the jaw 18 were directly in contact with this track or even if one end The beveled jaw of this jaw was in contact with the track 16 via a rotary member.

Said rotary element may in particular be a substantially spherical ball or preferably a substantially cylindrical roll. In the case of a roll, in a particular embodiment not shown, this roll may be mounted integral with an axis of rotation whose ends are slidable in slides provided at the end of the jaw in question, the orientation of said slides: substantially corresponding to the aforementioned beveled shape of the end of the jaw 18. This embodiment is very advantageous because it also makes it possible to reduce the friction forces even during crimping, since said roller can turn around its axis without rubbing against said end of the jaw.

In a preferred embodiment of the invention shown figure 9a , the track 16 has notches 32 at positions of said track facing each of the jaws 18 when the cam 12 is end of stroke relative to the jaw support 10, during crimping. Each of said slots 32 may for example correspond to a groove, substantially perpendicular to the plane of the figure 9a , practiced in said track 16; without departing from the scope of the invention, it may also correspond to a blind hole in the track 16. This is very advantageous because, at the end of crimping, the rotating element 30 is no longer in contact with the track 16 because of the presence of said notch. In this way, the rotary member 30 is more subject to frictional forces against this track 16 and it can easily move from said first position (corresponding to crimping) to said second position (corresponding to the return of the crimping tool in the rest position). The depth of this notch 32 in the track 16 is preferably determined taking into account the elastic deformation of the crimp contact: this depth is at least equal to the displacement of the jaw 18 under the effect of the elastic deformation of said contact, in the end crimping, when the jaw is no longer subjected to the forces applied by means of said rotary member 30. This ensures that the rotary member 30 is released from the friction forces on the track 16. More preferably, the depth of said notch 32 is smaller than the difference in distance d1, considered in projection on a line dr radial to the axis of the jaw support 10 and passing through the jaw 18, between the positions G1 and G2 occupied respectively by the center of gravity of the rotating element 30 on the one hand in said first position and secondly in said second position, represented on the figure 9b . In this way, it is guaranteed that the jaw 18 will not re-crimp the contact during the return of the crimping tool in the rest position. Another advantage of said notch 32 results from the fact that preferably the length it occupies on the track 16 is at most substantially equal to the width Lm of the jaw 18, said notch being, moreover, located at a position on the track 16 corresponding to the end of crimping. As a result, the track length 16 useful for the actual crimping is not significantly reduced due to the presence of said notch. Therefore, it is possible to conform said track 16 so as to distribute the crimping forces of the contact throughout the crimping movement, while benefiting from the aforementioned advantages of said notch 32 and said rotary member 30 as to the reduction of efforts friction, especially when returning the crimping tool 1 in the rest position.

In an embodiment shown on the figure 7 , said track 16 has portions 17 for centrifugal radial displacement of the jaws so as to release the jaws of the contact at the end of crimping. Such a portion 17 is provided at positions of said track facing each of the jaws when said cam is at the end of stroke relative to the jaw support, during crimping.

The various embodiments described above in the case of the first stage can, of course, apply to both the first floor and the second floor.

• dans un premier temps lesdits mors 28a du premier groupe sont déplacés de façon radiale vers le contact 34 pour le sertir, sans que les mors 28b du second groupe soient sensiblement déplacés, comme représenté sur la figure 10b. Cela a pour effet d'aplatir le contact 34 selon deux faces opposées correspondant aux extrémités planes des deux mors 28a de telle façon que la section dudit contact est sensiblement ovale ;
• dans un second temps, les mors 28b du second groupe sont déplacés de façon radiale vers le contact 34 pour le sertir, les mors 28a du premier groupe étant quant à eux maintenus sensiblement dans la position qu'ils occupaient dès la fin dudit premier temps, comme représenté sur la figure 10c. Cela a pour effet de donner audit contact 34 une forme d'abord sensiblement elliptique, puis de préférence sensiblement circulaire en fin de sertissage.

In a particular embodiment shown figure 10a the second stage has two groups of two jaws. The jaws 28a of the first group have ends capable of touching the crimp contact whose shape substantially corresponds to a plane whose orientation is substantially tangent to this contact during crimping. The jaws 28b of the second group have ends capable of touching the crimp contact whose concave shape corresponds substantially to a cylinder arc smaller than a half-cylinder. The two jaws 28a of the first group are arranged diametrically opposite on either side of the hole 6 of the jaw support 20 adapted to receive the crimp contact 34 and the two jaws 28b of the second group are arranged diametrically opposite side and side. other of said hole 6 of the jaw support 20 adapted to receive the crimp contact. In addition, the jaws 28b of the second group are oriented at an angle substantially equal to 90 degrees relative to the jaws 28a of the first group. The lengths of the jaws 28a of the first group on the one hand and the jaws 28b of the second group on the other hand, as well as the shape of the track 26 are advantageously provided so that, during crimping:

• at first said jaws 28a of the first group are moved radially towards the contact 34 to crimp, without the jaws 28b of the second group are substantially displaced, as shown in the figure 10b . This has the effect of flattening the contact 34 in two opposite faces corresponding to the planar ends of the two jaws 28a so that the section of said contact is substantially oval;
• in a second step, the jaws 28b of the second group are moved radially towards the contact 34 to crimp it, the jaws 28a of the first group being maintained in substantially the position they occupied at the end of said first time, as represented on the figure 10c . This has the effect of giving said contact 34 a substantially elliptical shape initially, then preferably substantially circular at the end of crimping.

• du type du mors 18a représenté figures 11 a et 11 b, qui comporte une extrémité 31 de forme convexe, apte à toucher le contact à sertir 34, dont une arête est apte à toucher ledit contact à sertir selon un seul segment 33 de ladite arête pour y former une partie concave; ou
• du type du mors 18b représenté figures 12a et 12b, qui comporte une extrémité 36 de forme convexe, apte à toucher le contact à y sertir 34, dont une arête est apte à toucher ledit contact à sertir selon deux segments disjoints 35a et 35b de ladite arête pour y former deux parties concaves, par exemple selon la norme MIL-C-22520.

The first stage, for its part, preferably comprises four identical jaws able to perform a crimping of the contact whose section comprises concave parts on its perimeter. Each of said jaws can in particular be:

• of the type of jaw 18a shown figures 11 a and 11b, which has an end 31 of convex shape, adapted to touch the crimp contact 34, one edge is adapted to touch said crimp contact in a single segment 33 of said edge to form a concave portion; or
• of the type of jaw 18b shown Figures 12a and 12b , which has an end 36 of convex shape, able to touch the crimp contact 34, one edge is adapted to touch said crimp contact two disjoint segments 35a and 35b of said edge to form two concave parts, for example according to MIL-C-22520.

Preferably, the four jaws of the first stage are arranged so that two neighboring jaws are offset from each other by an angle substantially equal to 90 degrees and that two jaws other than neighboring jaws are diametrically opposed from each other. else of the hole 6 of the jaw support 10 adapted to receive the crimp contact.

The crimping tool 1 according to the invention makes it possible to simultaneously actuate the first stage and the second stage by means of the first handle 4 and the second handle 2. In this way, it enables the crimping to be performed substantially simultaneously. contact 34 on the electrical core of the cable by means of the first stage and the crimping of this contact on an insulating sheath of the cable by means of the second stage. Since in the aforementioned preferred embodiments the first stage makes it possible to perform a crimping such that the section of the contact 34 has concave parts on its perimeter and the second stage makes it possible to perform a crimping such that the section in contact is substantially while reducing the efforts during the return of the crimping tool in the rest position, the crimping tool 1 according to the invention therefore advantageously solve the problems of the prior art.

Claims (21)

1. Crimping tool (1) to crimp a contact (34) onto the end of a wire, said wire end comprising a stripped part where a conductor core of the wire is exposed, and an insulated part where this conductor core is covered by an insulating jacket, said contact comprising a hole coaxial to the longitudinal axis of said contact able to receive both the stripped part and the insulated part of the wire end, said crimping tool comprising:

   - a first tier to crimp a first part of said contact onto the conductor core of the wire;

   - a second tier to crimp a second part of said contact onto the insulating jacket of the wire; and

   - means (2,4) for actuating said first and second tiers in substantially simultaneous manner;

   wherein:

   - said first and second tiers comprise crimping components (18,18a,18b,28,28a,28b) able to be moved in relation to the contact to be crimped, during crimping;

   - at least one of said first and second tiers comprises a cam (12,22) cooperating with the crimping components (18,18a,18b,28,28a,28b) of the tier under consideration and causing these components to move so that they crimp the contact, during crimping;

   characterized in that at least one rotating element (30) is arranged between at least one of said crimping components (18,18a,18b,28,28a,28b) and said cam (12,22), this rotating element possibly taking up at least two positions with respect to the crimping component under consideration so that when this rotating element is in contact both with this crimping component and with said cam, the distance between said cam and one end of this crimping component able to touch said contact for its crimping, is different in said at least two positions.
2. Crimping tool as in claim 1, characterized in that it is designed so that during movement of the cam (12,22) relative to the crimping components, in a first direction corresponding to crimping, said rotating element (30) takes up a first position with respect to said crimping component, in which said distance is maximal, and during movement of the cam relative to the crimping components in a second direction opposite to the first, said rotating element takes up a second position with respect to said crimping component, in which said distance is minimal.
3. Crimping tool as in either of claims 1 or 2, wherein said second tier comprises means (20,22,24,26,28a,28b) able to achieve crimping of substantially elliptical section.
4. Crimping tool as in any of the preceding claims, characterized in that the crimping components are jaws (18,18a,18b,28,28a,28b) able to be moved radial fashion to the contact to be crimped, during crimping.
5. Crimping tool as in claim 4, characterized in that said cam (12,22) is rotatably mounted about a jaw support (10,20), said cam (12,22) comprising a track (16,26) cooperating with ends of the jaws (18,18a,18b,28,28a,28b) to cause them to move radially towards the contact to be crimped, during crimping, these jaws being slidingly mounted in grooves (14,24) of the jaw support (10,20).
6. Crimping tool as in claim 5, characterized in that said at least one rotating element (30) is arranged between one jaw end and said track (16,26), this rotating element possibly taking up at least two positions with respect to the jaw end under consideration, such that when this rotating element is in contact both with this jaw end and with said track the distance, between said track and another end of this jaw able to touch said contact for its crimping, is different in said at least two positions.
7. Crimping tool as in claim 6, characterized in that the ends of jaws (18,18a,18b, 28,28a,28b) cooperating with the track (16,26) are bevelled, the rotating elements (30) being arranged between these bevelled ends and the track (16,26).
8. Crimping tool as in claim 7, characterized in that the bevelled end of a jaw is made so that the distance between this jaw and the track (16,26) of cam (12,22) is maximal at the rear of said jaw and minimal at the front thereof, the notions of front and rear being considered with respect to the direction of movement of said cam (12,22) in relation to the jaw support (10,20) during crimping.
9. Crimping tool as in any of the preceding claims, characterized in that said rotating element (30) is a substantially spherical bead.
10. Crimping tool as in any of claims 1 to 8, characterized in that said rotating element (30) is a substantially cylindrical roller.
11. Crimping tool as in claim 10, characterized in that said roller is secured to a hinge pin coaxial to this roller and whose ends are able to slide within rails secured to said jaw end.
12. Crimping tool as in any of claims 6 to 11, characterized in that said cam track (16,26) comprises a notch (32) at each position of said track facing each jaw with which a rotating element (30) is associated when said cam (12,22) has reached its travel limit relative to the jaw support (10,20), during crimping.
13. Crimping tool as in claim 12, characterized in that the depth of said notch (32) in the track (16) is:

    - at least equal to the displacement of the jaw corresponding to this notch under the effect of the elastic deformation of the contact to be crimped, at the end of crimping, when this jaw is no longer subject to the forces applied by means of said rotating element (30); and

    - less than the difference in distance (d1), considered when projecting onto a straight line (dr) radial to the axis of the jaw support (10) and passing through the jaw, between the positions (G1,G2) taken up by the centre of gravity of the rotating element (30) in said first position and in said second position respectively.
14. Crimping tool as in either of claims 12 or 13, characterized in that the length (Le) occupied by said notch (32) on the track (16) is no more than substantially equal to the width (Lm) of the jaw corresponding to this notch.
15. Crimping tool as in any of claims 5 to 14, characterized in that said track (16,26) has a shape able to allow a centrifugal radial movement of the jaws at the end of crimping so as to release these jaws from said contact.
16. Crimping tool as in any of claims 5 to 15, characterized in that the jaw supports (10,20) are secured to a first handle (4) and in that the cams (12,22) are secured to a second handle (2), said first and second handles being common to the first tier and second tier.
17. Crimping tool as in any of claims 3 to 16, characterized in that the second tier comprises two groups of two jaws such that:

    - the jaws (28a) of the first group have ends able to touch the contact to be crimped (34), their shape substantially corresponding to a plane whose orientation is substantially tangent to this contact during crimping;

    - the jaws (28b) of the second group have ends able to touch the contact to be crimped (34), their concave shape substantially corresponding to an arc of a cylinder smaller than a semi-cylinder;

    - the two jaws (28a) of the first group are arranged diametrically opposite either side of a hole (6) in the jaw support (20) able to receive the contact to be crimped (34);

    - the two jaws (28b) of the second group are arranged diametrically opposite either side of said hole (6) in the jaw support (20) able to receive the contact to be crimped (34);

    - the jaws (28b) of the second group are oriented at an angle of substantially 90 degrees with respect to the jaws (28a) of the first group.
18. Crimping tool as in any of claims 5 to 17, characterized in that said first tier comprises means (10,12,14,16,18a,18b) able to achieve crimping whose section has concave parts on its perimeter.
19. Crimping tool as in claim 18, characterized in that the first tier comprises four identical jaws (18a,18b) such that:

    - two adjacent jaws are offset from each other by an angle of substantially 90 degrees;

    - two jaws other than adjacent jaws are arranged diametrically opposite either side of a hole (6) in the jaw support (10) able to receive the contact to be crimped (34);

    - the ends of said jaws able to touch the contact to be crimped have a convex shape able to indent concave deformations in this contact during crimping.
20. Crimping tool as in any of the preceding claims, characterized in that said second tier comprises means able to achieve crimping of substantially circular section.
21. Method for crimping a contact (34) onto the end of a wire, said wire end comprising a stripped part where a conductor core of the wire is exposed and an insulated part where this conductor core is covered with an insulating jacket, said contact comprising a hole coaxial to the longitudinal axis of said contact, able to receive both said stripped part and said insulated part of the wire end, in which:

    - said contact (34) is inserted both in a first tier and in a second tier of a crimping tool (1) according to any of the preceding claims, which are arranged so that:

    • the first tier faces a first part of said contact surrounding the conductor core of the wire;

    • the second tier faces a second part of said contact surrounding the insulating jacket of the wire;

    - said first and second tiers are actuated in substantially simultaneous manner,

    - the actuation of the second tier comprises two successive steps:

    • two first jaws (28a) of the second tier are actuated, which lie diametrically opposite either side of the contact to be crimped, their ends touching this contact during crimping being substantially planar, these jaws being actuated until said contact is deformed along a substantially oval section,

    • said first jaws (28a) are held in position on the contact, and two second jaws (28b) of the second tier are actuated lying diametrically opposite either side of the contact to be crimped and oriented with respect to the first jaws (28a) at an angle substantially equal to 90 degrees, whose ends touching this contact during crimping are of concave shape substantially corresponding to an arc of a cylinder smaller than a semi-cylinder, said second jaws being actuated until said contact is deformed along a substantially circular section,

    characterized in that at the end of crimping, the jaws (18,18a,18b,28,28a,28b) of at least one tier are at least partly released under the effect of the movement of at least one rotating element (30) cooperating with a bevelled end of at least one of said jaws, so as to reduce the forces required to bring the crimping tool back to rest position.

Images