EP1166394A1

EP1166394A1 - Self-stripping connecting device for two electric cables

Info

Publication number: EP1166394A1
Application number: EP01907711A
Authority: EP
Inventors: Ariel Ruiz; Arsène Schmidt
Original assignee: ABB Entrelec SAS; Entrelec SAS
Current assignee: ABB France SAS
Priority date: 2000-02-07
Filing date: 2001-02-06
Publication date: 2002-01-02
Also published as: FR2804797A1; US20020155759A1; FR2804797B1; WO2001057957A1; US6604956B2

Abstract

The invention concerns a device with a conductive core (10a) and an insulating sheath (10b) comprising a stripping and retaining slot (18). It comprises: a second stripping and retaining slot (18) substantially parallel to the first and offset relative to the direction of the slots; a push-member (8) designed to receive two electric cables (10) and configured such that each cable should be located transversely opposite a stripping and retaining slot (18), and means (4) for producing a relative displacement between the push-member (8) and the stripping slots (18).

Description

Self-stripping connection device for two electric cables

The present invention relates to a self-stripping connection device for two electric cables.

A self-stripping connection device makes it possible to connect an electric cable to a conductive part without it being necessary beforehand to strip one end of the electric cable. The self-stripping connection device performs local stripping of the cable, for example by cutting the insulating sheath which is located around the conductive core, before making electrical contact between the conductive core thus locally stripped and the conductive part.

The documents EP-0 247 360 or even FR-2 723 474 disclose self-stripping connection devices. A self-stripping connection device comprising two stripping slots is revealed by the document FR-2 675 953. Here, the two holding and stripping slots are aligned and are intended for the connection of the same electric wire.

Known self-stripping connection devices make it possible to connect an electric cable with a predetermined diameter or whose predetermined diameter is within a fairly limited predetermined diameter range. In addition, when the known self-stripping connection devices make it possible to connect two electric cables, these must both be of the same diameter.

The present invention therefore aims to provide a self-stripping connection device for connecting two cables of different diameters.

To this end, the device which it offers is a self-stripping connection device for at least two electric cables having a conductive core and an insulating sheath, the device comprising a stripping and retaining slot. EP-0 247 360 discloses, for example, such a device.

According to the invention, this device comprises: - at least one other so-called second stripping and retaining slot (1 8), substantially parallel to the first and offset with respect to the direction of the slots,

- a pusher intended to receive at least two electric cables and shaped so that each cable can be transversely facing a stripping and retaining slot, - connecting means between the slots and the pusher allowing relative movement of the slots and of the pusher and guiding this movement, and

- Means for ensuring the relative movement between the pusher and the stripping slots. Thus, two stripping and retaining slots make it possible to connect each of an electric cable. The connection of one cable is therefore not influenced by the connection of the other cable. The connection of two cables of different diameters can be considered.

In a first embodiment of a connection device according to the invention, the two stripping and retaining slots are made on a blade folded in a U having two parallel branches of different lengths, each slot opening at the free end of each branch. The two stripping and retaining slots are then produced on the same conductive part. In this embodiment, the pusher comprises for example two profiled parts extending in the plane containing the two slots, transversely with respect to the slots and openings are advantageously provided for the passage of each slot and of the corresponding edges in the profiled parts . In this case, the width of each opening is for example such that it allows the part carrying the corresponding slot to be guided and ensures that the edges of the slot are tightened in abutment on the metallic core of a connected cable. The material used for the blade can therefore be chosen essentially for its qualities of good conductor without taking much account of its elastic mechanical qualities necessary to ensure good support of the edges of the slot on the bare conductive metallic core and thereby good contact. electric.

Provision can be made for the slots to be movable relative to the pusher, but it is of course also possible to have a movable pusher and fixed slots. Another more complicated solution to implement would be to have both movable slots and a pusher.

When the slots are movable, a screw is for example provided to ensure the displacement of the slots, this screw being engaged in a metal part connecting the two slots and immobile in translation relative to an insulating housing.

The relative movement between the slots and the pusher is for example a translation or else a pivoting movement.

In the case where the relative movement between the slots and the pusher is a pivoting movement, provision may be made for the slots to be carried by parallel curved blades, for the pusher to be pivotally mounted and to have two housings which are substantially transverse to the slots, openings being provided for the passage of the blades carrying the slots.

A screwdriver blade can be provided to ensure the pivoting movement of the pusher. A housing intended to receive the end of such a blade is then advantageously provided in the pusher.

The present invention also relates to a terminal block in which is placed a connection device as described above.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing, representing by way of nonlimiting examples two embodiments of a self-stripping connection device according to the invention. 'invention.

FIG. 1 is a perspective view showing the principle of a first embodiment, before connection of two electric cables,

FIG. 2 is a view corresponding to FIG. 1, the cables being connected,

FIG. 3 is a sectional view along the section line III-III of the device of FIG. 1, the latter being arranged in an insulating housing,

Figure 4 is a sectional view along the section line IV-IV of Figure 3, Figure 5 is a view corresponding to the view of Figure 4, the cables shown in Figure 4 being connected, and

Figure 6 is a longitudinal sectional view of a second embodiment of a connection device according to the invention.

Figures 1 and 2 are perspective views showing a connection principle according to the invention while Figures 3 to 5 show the device of Figures 1 and 2 in place in an insulating housing 2. In Figures 1 and 2, we can see a screw 4, a metal blade 6 folded into a U, a pusher 8 and two cables 10, each cable having a conductive core 10a and an insulating sheath 10b.

The metal blade 6 has a base 1 2 to which are attached two parallel branches 14 and 1 6. It will be considered in the following description that the base 12 of the blade 6 is located in a horizontal plane while the branches 14 and 1 6 extend in a vertical plane.

Each branch 14, 1 6 has a stripping and retaining slot 1 8 which is here rectilinear and parallel to the longitudinal axis of the corresponding branch 14, 1 6. Each slot 1 8 therefore extends vertically. The blade 6 is for example obtained from a flat flank by stamping resulting in cutting, then folding with possibly localized thinning. Each stripping and retaining slot 1 8 has at one end, the end corresponding to the free end of the branch 14, 1 6 corresponding, a stripping mouth 20. The latter is obtained by symmetrical oblique cutting of the edges of the slot 1 8. This oblique cut makes it possible to obtain a flared mouth, the edges of which form an edge making it possible to start the sheath 10b of an electric cable 10 pushed into the mouth 20.

The blade 6 is for example made of copper or else of a copper alloy with a high proportion of copper. Thus, when a cable 10 has been engaged in the slot 1 8 and its sheath 10b has been started at the mouth 20, the conductive core 10a of this cable is in electrical contact with the edges of the slot 1 8. The material constituting the blade then allows excellent conduction of the current passing through the electric cable.

The branches 14 and 1 6 have a different length. In the drawing, branch 14 is the shortest. The two slots 1 8 are substantially identical. These two slots are therefore offset in height and spaced from each other by a distance of the order of a few millimeters, or even a few tens of millimeters. In FIG. 1, an orthogonal coordinate system X, Y, Z has been represented, the Z axis defining the vertical and the X and Y axes a horizontal plane. It is assumed that the cables 10 extend parallel to the direction Y. The stripping and retainer 1 8 are then offset relative to each other on the one hand along the Y axis and on the other hand along the Z axis. Thus, the stripping slots are arranged in stairs or steps.

The base 12 of the blade 6 has a thread intended to cooperate with the threaded part 22 of the screw 4.

The pusher 8 has two profiled parts 24 and 26, the profiled part 24 being arranged above the profiled part 26.

The two profiled parts 24, 26 extend substantially along the axis Y. They are open profiled parts, the open side of the profile being oriented upwards, that is to say towards the blade 6.

The upper profiled part 24 is arranged, relative to the blade 6, so that it is crossed by the branch 1 6 but not by the branch 14. An opening 28 is provided to allow passage to the branch 1 6. Similarly, there is at the level of the section 24 an opening 30 provided to allow the passage of the branch 14 and an opening 32 produced in the section 26 and intended to receive the branch 1 6.

The profiled parts 24 and 26 are thus in the form of a gutter extending horizontally, transversely to the branches 14 and 1 6 and serve as a housing for cables 10 to be connected. The two profiled parts 24, 26 are for example made of steel. They can be linked to each other or be independent. In fact, it is planned to move the blade 6 relative to the pusher 8. This movement is done in the direction Z, that is to say the direction given by the slots 1 8. If the blade 6 moves, the profiled parts 24 and 26 are for example independent of one another while if the pusher 8 moves towards the blade 6, it is preferable to have two profiled parts integral with one another.

To make a connection of two cables 10, a cable 10 to be connected is introduced into each housing formed by the profiled parts 24 and 26. The cable 10 placed in the upper profiled part 24 is pushed in the direction of the axis Y until it comes into abutment against the branch 1 6. The cable placed in the lower housing of the profiled part 26 is associated with a stop not shown in the drawing. This stop is for example made in the insulating housing 2.

To move the blade 6 and bring the slots 18 down to the cables 10, the screw 4 is acted on. Each cable then comes into contact with a mouth 20 which cuts the insulating sheath 10b of the corresponding cable. By continuing to act on the screw 4, each cable 10 is stripped and its conductive core 10a is introduced between the parallel edges of the slot 18. An electrical contact is then made between the conductive core 10a and the blade 6. To guarantee good electrical contact between the edges of the slot of the branch 14 and of the upper cable 10 and the edges of the slot of the branch 1 6 and of the lower electrical cable, the openings 30 and 32 respectively intended to receive these branches 14 and 1 6 respectively are dimensioned so that the edges of the slots 1 8 are each time tightened towards the conductive core 10a of the corresponding cable in the case of large conductors. In the case of small conductors, the elasticity of the branches 14 and 1 6 is sufficient to ensure contact. Thus, the branches reinforced by the openings accept a wider connection range. In Figures 3 to 5, we can see the device of Figures 1 to 2 in place in the insulating housing 2. Figure 3 shows how the insulating housing holds the screw 4 and the blade 6 in position.

The screw 4 has a head 36 at the periphery of which is an annular rib 38. The latter is placed in a groove 40 of size and shape adapted to receive it. Thus, when a screwdriver acts on the screw head 36 to drive the screw 4 in rotation, it is not moved in translation so as to cause the translation of the blade 6. A core of synthetic material 42 is provided between the branches 14 and 1 6 so as to ensure perfect guidance of these branches during their translational movement. Any buckling phenomenon can thus be avoided during the stripping of a cable and its electrical connection. The core 42 can also serve as a support for the end of the screw 4 opposite its head 36.

In Figures 4 and 5, the blade 6 is shown in the high position and in the low position. Stops 44 are provided in the housing to allow indexing of the high position and the low position of the blade 6.

To extract a conductor 10 connected in a device as described above, the screw 4 is unscrewed. Thus, the blade 6 rises, carrying with it the conducting cables 10. The upper cable 10 comes into abutment on the insulation of the housing 2 (FIG. 3) and the lower cable 10 on the profiled part 24. By continuing the unscrewing, the blade 6 continues its ascent and the stripping of the cables 10 is carried out.

Figure 6 shows an alternative embodiment of a connection device according to the invention. In this figure, the parts having a function similar to that of parts of FIGS. 1 to 5 use the same references as these parts but are increased by the number 100.

We find in this embodiment a pusher 108, two cables 1 10, two branches 1 14 and 1 1 6 in each of which is made a slot not shown and terminated by a stripped mouth 1 20.

The branches 1 14 and 1 16 are the folded and curved ends of a conductive metal strip. These branches 1 14 and 1 1 6 have a radius of curvature and extend parallel to one another. The center of curvature of these two branches 1 14 and 1 1 6 is substantially the same. These branches are offset on the one hand radially and on the other hand angularly. The blades 1 14 and 1 1 6 are held in place in a housing 102 by virtue of a core 142 integral with this housing 102.

The pusher 108 is pivotally mounted around a point corresponding substantially to the center of curvature of the branches 1 14 and 126. Guide grooves, not shown, are produced in the interior walls of the housing 102 to allow good guiding of the pusher 108.

This pusher has three housings extending substantially radially relative to the pivot center. Two housings are provided for the cables 110 and a third housing 146 is intended to receive the end of a screwdriver blade 148. The pusher 108 also has openings 1 50 intended for the passage of the blades 1 14 and 1 1 6. In the position shown in Figure 6, before connecting the two cables 1 10, the mouths 120 of the blades 1 14 and 1 1 6 are at the entrance of the openings 1 50. These openings 1 50 are substantially perpendicular to the housing intended to receive the cables 1 10. They have a curved shape having for center of curvature substantially the same center of curvature as that of the branches 1 14 and 1 1 6.

To make the connection of two cables 1 10, these are introduced into the housings provided for this purpose in the pusher 108. A first cable 1 10 abuts against the branch 1 1 6 while the housing for the other cable 1 10 is blind. The end of the screwdriver blade 148 is then introduced into the housing 146. An opening 1 52 made in the housing 102 allows the insertion into their respective housing of the cables 1 10 and the screwdriver blade 148. By then pivoting the pusher 108 using the screwdriver blade 148 towards the branches 1 14 and 1 1 6, the cables 1 10 are then stripped and held in the stripping and retaining slots of these blades. This makes the connection of the two cables 1 1 0.

To ensure good electrical contact between the branches 1 14 and 1 1 6 and the conductive core of the cables 1 1 0, provision may be made for the width of the openings 1 50 to be such that in the connected position the edges of the stripping slots and retainers are tightened on the conductive core of the cable 1 10. We can then use for the material of the branches 1 14 and 1 1 6 a material which is very good conductor without having excellent mechanical properties from the point of view elasticity.

In this embodiment, compared to that shown in Figures 1 to 5, there is a movable pusher and stationary stripping and retaining slots. In addition, the relative movement between the pusher and the slots is not a translational movement but a rotational movement. Here, the two stripping and retaining slots are not produced on the same blade but on two separate blades which are in electrical contact with each other.

The embodiments described above and shown in the drawing show connection devices which allow an excellent connection of two cables, even if these are of different diameters.

In fact, since the two cables are connected to separate stripping and retaining slots, the cable of larger diameter does not prevent the connection of a cable of smaller diameter. The two stripping and retaining slots of the same connection device according to the invention can both be provided for the cable connection whose diameter lies within the same predetermined range. However, one can provide a stripping and retaining slot intended to receive cables of large diameters and a stripping and retaining slot intended for cables of smaller diameters. In all cases, the connection of one electric cable has no influence on the connection of the other electric cable. It goes without saying that the invention is not limited to the embodiments described above by way of nonlimiting examples; on the contrary, it embraces all of the variant embodiments thereof within the scope of the claims below. Thus, the embodiments described show either a fixed pusher with slots moving in translation or fixed slots with a mobile pusher moving in rotation. It is of course possible to have a mobile pusher moving in translation or mobile blades moving in rotation. Other means for carrying out the displacement of the pusher or of the slots can be envisaged. One can for example imagine a blade or a pusher projecting from the housing and intended to be moved by direct action of a finger of an operator.

Likewise, in the examples described above, the arrangements according to the invention allow the connection of two cables. However, according to the invention, a connection device could allow the connection of three or more cables.

To this end, the connection device comprises as many stripping slots as there are cables to be connected, the stripping slots preferably being all aligned along the same plane and offset in two directions. Thus, the slots are arranged in stairs or steps. In addition, the device comprises as many receiving housings as there are cables to be connected. Each housing is then adapted to ensure the engagement of the cable which it receives in the corresponding stripping slot. It should be noted that, like the stripping slots, the housings are also arranged in stairs or steps.

Claims

1. Self-stripping connection device for at least two electric cables (10; 1 10) having a conductive core (10a) and an insulating sheath (10b), the device comprising a stripping and retaining slot (18), characterized in that that it includes:

- at least one other so-called second stripping and retaining slot (18), substantially parallel to the first and offset with respect to the direction of the slots,

- a pusher (8; 108) intended to receive at least two electric cables (10; 1 10) and shaped so that each cable can be transversely facing a stripping and retaining slot (18), - means (2, 102) of connection between the slots (1 8) and the pusher (8, 108) authorizing a relative movement of the slots and of the pusher and ensuring guidance of this movement, and

- Means (4; 108, 146) for ensuring the relative movement between the pusher (8; 108) and the stripping slots (1 8).

2. Connection device according to claim 1, characterized in that the two stripping and retaining slots (1 8) are formed on a blade (6) folded in a U having two branches (14, 1 6) parallel with different lengths , each slot (18) opening at the free end of each branch.

3. Connection device according to one of claims 1 or

2, characterized in that the pusher (8) has two profiled parts (24; 26) extending in the plane containing the two slots (18), transversely with respect to the slots and in that openings (30,32) are provided for the passage of each slot and the corresponding edges in the profiled parts.

4. Connection device according to claim 3, characterized in that the width of each opening (30,32) is such that it allows the guide of the part carrying the corresponding slot and ensures a tightening of the edges of the bearing slot on the metallic core (10a) of a connected cable.

5. Connection device according to one of claims 1 to 4, characterized in that the slots (1 8) are movable relative to the pusher (8).

6. Connection device according to claim 5, characterized in that a screw (4) is provided to move the slots (18), this screw being engaged in a metal part (1 2) connecting the two slots and stationary in translation relative to an insulating housing (2).

7. Connection device according to claim 1, characterized in that the relative movement between the slots and the pusher (108) is a pivoting movement.

8. Connection device according to claim 7, characterized in that the slots are carried by curved blades (1 14; 1 1 6) parallel, in that the pusher (108) is pivotally mounted and has two substantially transverse housings by relative to the slots, openings (1 50) being provided for the passage of the blades (1 14; 1 1 6) carrying the slots.

9. Connection device according to one of claims 7 or 8, characterized in that a housing (146) intended to receive the end of a screwdriver blade (148) is provided in the pusher (108).

10. Terminal block according to claim 9, characterized in that it comprises at least one connection device according to one of claims 1 to 9.