FR2882469A1 - Connection device for horizontal distribution comb, has contact screw comprising body presenting, opposite to head, annular portion whose free end forms cutting edge that surrounds outlet of cavity - Google Patents

Abstract

The device has a contact screw (13) comprising a body (20) which, at the opposite to a head (21), presents an annular portion (24) surrounding a cavity (25). The annular portion has a free end forming a cutting edge (26) surrounding an outlet of the cavity. Slots are arranged in the annular portion from the edge and distributed equi-angularly, so as to form a tooth between two consecutive slots. An independent claim is also included for an assembly comprising a connection device and a horizontal distribution comb on which the device is installed.

Description

FIELD OF THE INVENTION

  The invention relates to connection devices to a conductor covered with an insulating layer.

BACKGROUND

  Numerous devices of this type are already known, which comprise contact means adapted to engage the conductor after passing through the insulating layer from the outside.

  There are thus connectors for electrical power distribution cables having a jaw whose jaws have teeth that perforate the insulation of the electric cable when the jaw is tightened and come to engage on the core of the cable, another cable that can be connected to the jaw via a terminal provided on this connector.

  There are also various connection devices for a horizontal distribution comb comprising a sill covered with an insulating envelope, in particular screw connection devices piercing the insulating envelope or so-called self-stripping pliers.

  OBJECT OF THE INVENTION The object of the invention is to provide a connection device suitable for reliably and conveniently allowing an electrical connection on a horizontal distribution comb or on another element comprising a conductor having two opposing faces close to an edge. covered with insulation.

  The invention proposes for this purpose a connection device to a conductor covered with an insulating layer, having contact means adapted from the outside, to pass through said insulating layer and to engage on said conductor; characterized in that said contact means comprise a screw having an annular portion surrounding a cavity, with the free end of said annular portion which forms a cutting edge with a generally circular contour, surrounding the outlet of said cavity.

  The cutting edge of the contact screw is thus capable, when this screw is tightened, of cutting into the insulating layer a pellet which lodges in the cavity so that this ridge can then penetrate, without being impeded by the insulating layer, in the driver.

  The fact that the contact surface between the conductor and the screw has a circular contour allows this surface to have a relatively high value, ensuring good electrical conductivity, which reduces the risk of heating in a simple and effective manner.

  According to preferred features, for reasons of reliability and convenience: said annular portion has slots, formed from said cutting edge, so that a regular succession of teeth is formed; said cutting edge is located at the junction between the lateral surface of said cavity, which is generally oriented axially, and a chamfer formed at the end of an external lateral surface of said contact screw; said contact screw comprises a body and a head connected to each other by a frangible zone having a section with a reduced diameter, said annular portion being part of said body and being disposed opposite said head; said frangible zone is delimited laterally by the bottom of a V-shaped groove, the blanks of which belong respectively to said body and to said head; said head has a maneuvering footprint; said device comprises a rider made of conductive material having a body and two legs protruding from said body and delimiting with the latter a groove whose bottom belongs to said body and whose respective lateral surfaces belong to one and the other of said jambs, a first of said leg having a tapped through hole adapted to cooperate with said contact screw; the lateral surface of said groove belonging to the second of said legs has at least one protruding insulating displacement member; said lateral surface of said groove belonging to the second leg has at least one longitudinal rib having a V-shaped section converging towards a cutting edge; said lateral surface of said groove belonging to the second leg has at least one claw; said claw comprises a circular flat base from which a sharp member projects, said base being crimped into a recess of corresponding shape of said second leg; - The face of said base protruding said sharp member is flush with the inner surface of said second leg; said sharp member is a corner; said sharp member is a tip; the lateral surface of said groove belonging to the second of said legs has at least one protruding member for cutting insulation; said insulating cutting protruding member has a cutting ring surrounding a cavity, with the free end of the cutting ring forming a cutting edge with a generally circular contour, surrounding the outlet of said cavity; said cutting ring has slots, formed from said edge slice, so that is formed a regular succession of teeth; said cutting edge is at the junction between the lateral surface of said cavity, which is generally oriented axially, and a chamfer forming the outer lateral surface of said cutting ring; said cutting ring belongs to a screw disposed in a threaded hole formed in the second of said legs; - Said screw has opposite said cutting ring a flat face disposed flush with the outer lateral surface of the second of said legs; said jumper comprises two so-called threaded through holes adapted to cooperate with a said contact screw; said body of said jumper includes connection means for at least one electrical cable; - Said connecting means comprise for each cable a bore adapted to receive said cable, and a threaded hole opening into said bore adapted to cooperate with a set screw; said body has two said tapped holes opening into a said bore; said device comprises two covers of suitable insulating material, when they are assembled to each other on said jumper, to cover it; and / or - said two covers each have a different color.

  The invention also aims, in a second aspect, an assembly comprising a connection device as explained above and a horizontal distribution comb on which is installed said device, with said annular portion of said contact screw which passes through a insulating jacket surrounding a sill included in said comb and with said cutting edge which is in contact with said sill.

  Preferably, to allow easy identification of the pole to which the comb is carried, said device comprises two covers of suitable insulating material, when they are assembled to each other on said jumper, to cover it, said two caches each have a different color, said insulating envelope having on each side the same color as the corresponding cache.

BRIEF DESCRIPTION OF THE DRAWINGS

  The disclosure of the invention will now be continued by the detailed description of a preferred embodiment, given below by way of illustration and not limitation, with reference to the accompanying drawings. On these: - Figure 1 is a top view of an assembly comprising a row of modular electrical appliances, of which only the one on the left is illustrated to simplify the drawing, and two unipolar combs of horizontal distribution, the comb that is seen at the top being equipped with a connection device according to the invention while the comb that is seen at the bottom is in the process of equipping such a device; - Figure 2 is the sectional view marked II-II in Figure 1; - Figure 3 is an enlargement of the portion of Figure 2 at the level where the jumper of the connection device overlaps the comb on which this device is being mounted; FIG 4 is a perspective view of one of the contact screws that includes this connection device; FIG. 5 is an end view of this screw, taken from the side that is seen on the right in FIG. 4; - Figure 6 is the sectional view indicated by VI-VI in Figure 5; FIG. 7 is a perspective view of the jumper included in this connection device; - Figure 8 is a view similar to Figure 7, but for a variant of the jumper; FIG. 9 is a view similar to FIG. 3, but for the variant of the connection device comprising the jumper illustrated in FIG. 8; and - Figure 10 is a similar view for another variant of the rider; - Figures 11 and 12 are views similar to Figures 8 and 9 for yet another variant of the rider; and FIG. 13 is a perspective view of one of the screws provided with the jumper illustrated in FIGS. 11 and 12, the annular portion that is seen on the right of FIG. 13 serving this protruding member jumper. insulation cutting.

  DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

  The assembly 1 shown in Figure 1 comprises a row of electrical appliances, of which only the apparatus 2 is illustrated, and two unipolar combs of horizontal distribution 3 and 4.

  The apparatus of the row to which the apparatus 2 belongs are arranged side by side and have the same format, called modular, each apparatus having a generally parallelepiped shape with two main faces and side faces extending from one to the other. other main faces, in this case a rear face, a lower face, a front face and an upper face.

  In each apparatus, the rear face is provided with a notch for mounting on a horizontal rail (not shown) with a standard profile, generally 0, while the upper face has orifices such as orifices 5 and 6 of the appliance. 2, giving access to input connection terminals for either of the poles of an AC power source, namely the neutral pole and the phase pole.

  The power supply of the device 2 and that of the modular devices located on the same row is performed with the two combs 3 and 4, respectively carried to the neutral potential and the phase potential of the AC power source.

  The connecting device 7 equipping the comb 3 and the connection device 8 being mounted on the comb 4 are provided for connecting the combs 3 and 4 respectively to the poles of the alternating current source. .

Combs 3 and 4 are identical.

  As can be seen more particularly in FIG. 2, they each comprise a sill 9 in the form of a continuous strip and a plurality of teeth 10, here thirteen in number, protruding from the sill 9.

  The sill 9 and the teeth 10 are made of a single piece in a metal material good conductor of electricity.

  The sill 9 and the teeth 10 are here oriented in the same plane.

  The teeth 10 are regularly distributed, according to a pitch (spacing between two consecutive teeth) corresponding to the width of an apparatus such as 2, that is to say the normalized distance between its lateral faces known as the module, which is of the order of 18 mm.

  The combs 3 and 4 each comprise, in addition to the sill 9 and the teeth 10, a casing 11 of U-shaped insulating material which covers the sill 9 of its edge opposite the teeth 10 to the root of the teeth 10. The connection devices 7 and 8 are identical.

  We will now describe the connection device 8 being mounted on the comb 4.

  The device 8 comprises a jumper 12, two contact screws 13, two pressure screws 14 (illustrated in FIG. 2 alone) and two covers 16 and 17 made of insulating material.

  As can be seen more particularly in FIGS. 4 to 6, the contact screw 13 comprises a body 20 and a head 21 connected to one another by a frangible zone 22 having a reduced diameter section, the zone 22 being here delimited laterally by the bottom of a V-shaped groove 23 whose blanks respectively belong to the body 20 and to the head 21.

  As will be seen below, the diameter of the frangible zone 22 is determined so that there is a rupture of the zone 22 when it exerts a predetermined torque of intensity between the body 20 and the head 21.

  The body 20 has, opposite the head 21, an annular portion 24 surrounding a cavity 25. The free end of the annular portion 24 forms a cutting edge 26 with a generally circular contour, surrounding the outlet of the cavity 25.

  In the annular portion 24, from the edge 26 and to a certain depth, are formed slots 27, here six in number, distributed equi-angularly, so that are formed teeth each located between two consecutive slots 27 .

  The edge 26 is at the junction between the lateral surface of the cavity 25, which is relatively straight, that is to say generally parallel to the axis of the screw 13, and a chamfer 28 formed at the end of the lateral surface of the body 20, which lateral surface is threaded.

  The head 21 has an imprint 29 with a hexagonal contour, for the operation of the screw 13 by means of a wrench of the same contour, such as the bent key 30 illustrated in FIGS. 1 to 3.

  The rider 12 has a body 31 and two legs 32 and 33 protruding from the body: 31.

  Here, the jumper 12 is made of a single piece in a block of good electrically conductive metal material with a generally parallelepipedal shape having a generally U-shaped groove 34 whose bottom belongs to the body 31 and whose side surfaces belong respectively to jamb 32 and jamb 33.

  The lateral surface of the groove 34 belonging to the leg 32 has two longitudinal ribs 35 arranged parallel to one another, having a relatively acute V-section converging towards a cutting edge.

  The leg 33 has two threaded holes 36 arranged next to each other in the longitudinal direction, each hole 36 completely passing through the leg 33 and having a thread corresponding to the thread of the body 20 of the screw 13.

  In view of each hole 36, the ribs 35 have an interruption.

  The body 31 is traversed right through by a bore 37 oriented longitudinally.

  On the same side as the leg 33, the body 31 has two threaded holes 38 arranged side by side in the longitudinal direction, each hole 38 being oriented in the transverse direction and opening into the bore 37. The tapping of the holes 38 corresponds to the threading of the pressure screw 14.

  As seen more particularly in Figures 2 and 3, the legs 32 and 33 have a height, corresponding to the depth of the groove 34, slightly less than the height of the insulating casing 11 while the width of the groove 34 is greater than the width of the casing 11, so that the jumper 12 can overlap the casing 11 with the latter arranged in the groove 34, as shown in Figures 1 to 3.

  The covers 16 and 17 made of insulating material each have a side wall 40 (FIG. 2) whose inner surface has the same dimensions as the lateral surfaces of the jumper 12. Each of the covers 16 and 17 has a projection with respect to the external surface. the wall 40, two eyelets 41 arranged in the extension of an orifice of the wall 40. The orifices in the extension of which are the eyelets 41 are arranged relative to the inner surface of the wall 40 as are the holes 38 relative to the corresponding external lateral surface of the rider 12.

  The wall 40 of each of the covers 16 and 17 is connected, on one side, to a bottom wall 42 having the same width as the jamb 32 or the jamb 33, and, on the other side, to a roof wall. 43 whose width corresponds to half that of rider 12.

  At each transverse end, the cover 16 and the cover 17 have a wall 44 of the same profile as a half of a transverse end face of the rider 12.

  To allow their assembly to one another, the covers 16 and 17 have, in their roof wall 43, respectively two notches 45 and two corresponding hooking tabs 46 while the walls 44 respectively have a hooking notch 47 and a corresponding latching lug 48.

  When the covers 16 and 17 are assembled to each other on the jumper 12, they completely cover it, with the exception of the groove 34 and the bore 37 while the eyelets 41 and the corresponding holes of the wall 40 allow access to the threaded holes 38, and more precisely to the screws 14 engaged in these holes.

  In the connecting device 8, the cover 17 is provided to be disposed on the side of the screws 14 and the cover 16 on the other side, whereas in the connection device 7, it is the cover 16 which is arranged on the side screws 14 and the cover 17 on the other side.

  This allows, the covers 16 and 17 having a different color, to match the color of the caches that is visible by the user to the color chosen to identify the pole of the AC power source to which it is intended to connect the comb on which is mounted the connection device.

  Here, the comb 3 is provided to be connected to the neutral pole and the cover 16 is of the color chosen to identify this pole (here, the blue color) while the comb 4 is provided for the phase pole and the cover 17 is of the color chosen to identify this pole (here, the black color), so that in the connecting device 7 equipping the comb 3, it is the cover 16 which is on the side of the screws 14 while in the device of connection 8 is the cover 17 which is on the side of the screws 14.

  Note also that the envelope 11 of the combs 3 and 4 is blue on one side and black on the other side, and in order to identify the poles to which they are worn, the comb 3 is arranged so that it is the blue side of the envelope 11 which is visible and the comb 4 so that it is the black side that is visible.

  We will now explain how we proceed to the mounting of the connection device 8 on the rail 4, it being understood that the mounting of the connection device 7 on the rail 3 is identical, if not, as just explained, that the arrangement of the covers 16 and 17 is reversed.

  The jumper 12, provided for each hole 36 with a screw 13 and for each hole 38 of a screw 14, is arranged astride the insulating envelope 11 of the comb 4, with the leg 32 arranged on the rear side and the jamb 33 of the front side, the bottom of the groove 34 resting on the edge of the casing 11.

  A tool such as the bent key 30 is then used to tighten one and the other of the screws 13.

  When the cutting edge 26 of the body 20 of the screw 13 being maneuvered meets the insulating envelope 11, it cuts out in the latter a pellet 50 which is gradually housed in the cavity 25.

  When the pellet 50 is completely cut, that is to say when the casing 11 has been completely traversed from the outside by the annular portion 24, the ridge 26 meets the sill 9 and begins to enter the latter.

  At the same time that the annular portion 24 penetrates into the casing 11 on the side of the leg 33, the ribs 35 penetrate into this casing on the side of the leg 32, until their edge meets the sill 9.

  The predetermined pair mentioned above, beyond which the frangible zone 22 of the screw 13 breaks, is large enough for the rupture to occur only after the portion 24 and the ribs 35 have come to meet the sill 9 and that the ribs 35 and the portion 24 have penetrated at least partially into the sill 9, the torque remaining small enough that the break can easily occur with a simple bent key 30.

  It will be observed (FIG. 3) that the length of the body 20 of the screw 13 is such that at the moment when rupture of the frangible zone 22 occurs, this zone is located inside, or at least flush with the outlet. of the tapped hole 36, so that after rupture there is no portion of the screw 13 protruding from the rider 12.

  The breakability of the screw 13 allows the user to be sure that he has exerted on the latter a sufficient torque for a good quality electrical contact to be established between the jumper 12 and the sill 9 of the comb.

  The fact that the contact surface between the body 20 of the screw 13 and the sill 9 has a circular contour allows this surface to have a relatively high value, ensuring good electrical conductivity.

  The ribs 35, which are in contact with the sill 9, also participate in the conductivity between the rider 12 and the sill 9. The ribs 35 also provide, mechanically, a counter-support to the screw 13.

  Once the two screws 13 have been tightened until breaking of the breakable zone 22, the covers 16 and 17 can be put in place.

  Of course, the connection devices 7 and 8 are mounted on the combs 3 and 4 while the combs 3 and 4 are away from each other and from any other element that may interfere with the assembly, and not in the configuration illustrated in Figures 1 and 2, which shows only a simple convenience of the device 8 being mounted while the combs 3 and 4 are in place on the row of modular devices to be powered.

  The bore 37 of the jumper 12 makes it possible to receive the stripped end of a relatively strong section cable whose other end is connected to one of the poles of the electrical power source, the immobilization of the stripped end. the cable engaged in the bore 37 being made by tightening the pressure screw 14.

  Each connecting device 7 and 8 also allows the connection of a second cable of large section, engaged in the other end of the bore 37 and held in place by the second pressure screw 14, which allows the transplanting to the other combs serving another row of apparatus such as 2.

  We will now describe the 12 'variant of the jumper illustrated in Figures 8 and 9. We kept for the elements identical to those of the jumper 12 the same reference numbers.

  The jumper 12 'is identical to the jumper 12, except that the ribs 35 are replaced by two added claws 55 each arranged opposite a respective one of the threaded holes 36.

  Each claw 55 has a circular flat base 56 which protrudes an acute corner 57. The base 56 is crimped into a recess of corresponding shape of the jamb 32, so that the face of the base 56 which the corner 57 protrudes is flush of the inner surface of the jamb 32.

  The variant 12 "of the jumper illustrated in FIG. 10 will now be described. The same references have been used for the identical elements as for the jumper 12.

  The jumper 12 "is identical to the jumper 12 ', except that the claws 55 are replaced by claws 60 whose sharp member 62 protruding from the base 61 is not wedge-shaped, but shaped tapered tip.

  We will now describe the 12 "'variant of the jumper illustrated in Figures 11 and 12. We kept for the elements identical to those of the jumper 12 the same reference numbers.

  The jumper 12 "'is identical to the jumper 12, except that the ribs 35 are replaced by cutting rings 63 each disposed opposite a respective one of the threaded holes 36.

  Here, each cutting ring 63 belongs to a screw 64 shown alone in FIG.

  In general, the screw 64 is shaped in the same way as the body 20 of the screw 13, except that it does not have a chamfer connecting it to a frangible zone such as 22, but flat face in which is provided a maneuvering footprint 65.

  Each cutting ring 63 is formed by an annular portion of a screw 64, this annular portion surrounding a cavity 66, with the free end of the annular portion 63 which forms a cutting edge 67 with a generally circular contour, surrounding the outlet of the cavity 66.

  As in the annular portion 24 of the screw 13, in the annular portion 63 of the screw 64, from the edge 67 and to a certain depth, are formed slits 68, here four in number, distributed equi -angularly, so that are formed teeth each located between two consecutive slots 68.

  The edge 67 is at the junction between the lateral surface of the cavity 66, which is relatively straight, that is to say generally parallel to the axis of the screw 64, and a chamfer 69 formed at the end of the lateral surface of the screw 64, which lateral surface is threaded.

  As seen more particularly in FIG. 12, the screw 64 is installed in a tapped hole similar to a hole 36.

  For reasons of simplification of the manufacture of the body 31 of the jumper 12 ", each tapped hole for receiving a screw 64 is aligned with a hole 36.

  When the flat face of the screw 64 opposite the annular portion 63 is flush with the outer lateral surface of the leg 32, as shown in FIG. 12, the annular portion 63 protrudes from the inner lateral surface of the leg 32 and thus forms a cutting ring, that is to say a projecting member for cutting the insulating envelope of a horizontal distribution comb.

  The impression 65 is here an imprint for a flat-blade screwdriver, the setting up of the screws 64 in the body 31 to the position shown in FIG. 12 taking place prior to the mounting of the jumper 12 'on a comb such as combs 3 and 4. 30

  Thus, during mounting on a comb, at the same time that the annular portion 24 of the screw 13 penetrates into the casing 11 on the side of the leg 33, the cutting ring 63 enters this casing on the side of the jamb 32, until have cut into the envelope 11 a pellet 70 which is gradually housed in the cavity 66, and when the pellet 70 has been completely cut, that is to say when the envelope 11 has been completely crossed, the edge 67 comes to meet the sill 9 and enters the latter.

  The jumper 12 offers the advantage that the ribs 35 can be in one piece with the rest of the body 31, a blank of which is obtained by extrusion.

  The jumper 12 is suitable when the insulating layer such as the envelope 11 is relatively soft.

  Clawed jumpers 12 'and 12 "are well suited for relatively hard insulating layers.

  As for the rider 12 "'it is appropriate, thanks to the cutting rings 63, 15 to both soft insulating layers and relatively rigid insulating layers.

  In a variant not shown, the contact screw 13 is replaced by a screw also having an annular portion surrounding a cavity, with the free end of the annular portion which forms a cutting edge, but shaped differently, for example with different slots of the slots 27 or without such slots, and / or an actuating fingerprint directly in the body such that 20.

  In another variant not shown, the inner surface of the leg 32 is provided with a protruding insulating displacement member different from the ribs 35 and the claws 55 or 60, is provided with a protruding insulating cutting member different from the rings 63, or then has no protruding member (this surface is flat), the leg 32 simply resting on the insulating casing 11.

  In other variants not shown, the jumper 12 is replaced by a jumper also having a body and two legs defining a central groove, but is arranged differently than the jumpers 12, 12 ', 12 "and 12"' with for example only one contact screw such as 13 or more than two contact screws; a single pressure screw such as 14 or more than two setscrews; and / or with the connecting terminal portion for a relatively large section cable which is arranged differently, for example with the cable receiving bore which is oriented vertically rather than horizontally.

  In still other variants not shown, the connection device is not installed on the sill 9 covered with an envelope 11 of a horizontal distribution comb, but on another conductor covered with an insulating layer, for example a painted sheet metal of an electrical cabinet or other relatively rigid conductor having near two edges a slice opposite each covered with an insulating layer.

  Many other variants are possible depending on the circumstances, and it is recalled in this regard that the invention is not limited to the examples described and shown.

Claims (28)

  Device for connecting to a conductor (9) covered with an insulating layer (11), having suitable contact means, from the outside, to pass through said insulating layer (11) and to engage said conductor (9); characterized in that said contacting means comprise a screw (13) having an annular portion (24) surrounding a cavity (25), with the free end of said annular portion (24) forming a cutting edge (26) with a contour globally circular, surrounding the outlet of said cavity (25).   2. Device according to claim 1, characterized in that said annular portion (24) has slots (27) formed from said cutting edge (26), so that is formed a regular succession of teeth.   3. Device according to any one of claims 1 or 2, characterized in that said cutting edge (26) is at the junction between the lateral surface of said cavity (25), which is generally oriented axially, and a chamfer ( 28) formed at the end of an external lateral surface of said contact screw.   4. Device according to any one of claims 1 to 3, characterized in that said contact screw comprises a body (20) and a head (21) connected to one another by a frangible zone (22) having a reduced diameter section, said annular portion being part of said body (20) and being disposed opposite said head (21).   5. Device according to claim 4, characterized in that said frangible zone (22) is delimited laterally by the bottom of a groove (23) V profile whose blanks belong respectively to said body (20) and said head ( 21).   6. Device according to any one of claims 4 or 5, characterized in that said head (21) has a maneuvering footprint (29).   7. Device according to any one of claims 1 to 6, characterized in that it comprises a jumper (12; 12 '; 12 "; 12"') of conductive material having a body (31) and two legs (32). 33) protruding from said body (31) and delimiting therewith a groove (34) whose bottom belongs to said body (31) and whose respective lateral surfaces belong to both of said legs (32). , 33), a first (33) of said leg having a tapped through hole (36) adapted to cooperate with said contact screw (13).   8. Device according to claim 7, characterized in that the lateral surface of said groove (34) belonging to the second (32) of said legs has at least one projecting member (35; 55; 60) of insulation displacement.   9. Device according to claim 8, characterized in that said lateral surface of said groove (34) belonging to the second leg (32) has at least one longitudinal rib (35) having a V-shaped section converging towards a cutting edge.   10. Device according to claim 8, characterized in that said lateral surface of said groove (34) belonging to the second leg (32) has at least one claw (55; 60).   11. Device according to claim 10, characterized in that said claw (55; 60) comprises a circular flat base (56; 61) which protrudes a sharp member (57; 62), said base (56; 61) being crimped in a correspondingly shaped recess of said second leg (32).   12. Device according to claim 11, characterized in that the face of said base (56; 61) which protrudes said sharp member is flush with the inner surface of said second leg (32).   13. Device according to claim 12, characterized in that said sharp member is a wedge (57); 14. Device according to claim 12, characterized in that said sharp member is a tip (62).   15. Device according to claim 7, characterized in that the lateral surface of said groove (34) belonging to the second (32) of said legs has at least one projecting member (63) for cutting insulation.   16. Device according to claim 15, characterized in that said projecting member (63) for cutting insulation has a cutting ring (63) surrounding a cavity (66), with the free end of the cutting ring which forms a sharp edge (67) with a generally circular contour, surrounding the outlet of said cavity (66).   17. Device according to claim 16, characterized in that said cutting ring (63) has slots (68), formed from said cutting edge (67), so that is formed a regular succession of teeth.   18. Device according to any one of claims 16 or 17, characterized in that said cutting edge (67) is at the junction between the lateral surface of said cavity (66), which is generally oriented axially, and a chamfer ( 69) forming the outer lateral surface of said cutting ring (63).   19. Device according to any one of claims 15 to 18, characterized in that said cutting ring (63) belongs to a screw (64) disposed in a threaded hole in the second (32) of said legs.   20. Device according to claim 19, characterized in that said screw (64) has opposite said cutting ring (63) a flat face disposed flush with the outer side surface of the second (32) of said legs.   21. Device according to any one of claims 7 to 20, characterized in that said jumper comprises two said threaded through holes (36) adapted to cooperate with said contact screw (13).   22. Device according to claim 7, characterized in that said body (31) of said jumper (12; an electric cable.   23. Device according to claim 22, characterized in that said connecting means comprise for each cable a bore (37) adapted to receive said cable, and a threaded hole (38) opening into said bore (37) adapted to cooperate with a pressure screw (14).   24. Device according to claim 23, characterized in that said body (31) has two said tapped holes (38) opening into a said bore (37).   25. Device according to any one of claims 7 to 24, characterized in that it comprises two covers (16, 17) of suitable insulating material, when they are assembled to each other on said rider (12). 12 '; 12 "; 12w), to cover this one.   26. Device according to claim 25, characterized in that said two covers (16, 17) each have a different color.   27. An assembly comprising a connection device (7, 8) according to any one of claims 1 to 26 and a horizontal distribution comb (3, 4) on which said device is installed, with said annular portion (24) of said contact screw (13) which passes through an insulating envelope (11) surrounding a sill (9) that comprises said comb (3, 4) and with said cutting edge (26) which is in contact with said sill (9).   28. The assembly of claim 27, characterized in that said device (7, 8) comprises two covers (16, 17) of suitable insulating material, when they are assembled to one another on said jumper (12; 12 '; 12 "; 12w), to cover it, said two covers (16, 17) each have a different color, said insulating envelope having on each side the same color as the corresponding cover (16, 17).