FR2777132A1 - DEVICE AND METHOD FOR ELECTRICAL CONNECTION BETWEEN A BAR AND A CONDUCTOR AND ELECTRICAL CONNECTION ASSEMBLY INCLUDING SUCH A DEVICE - Google Patents

Abstract

Device for electrical connection between a bar (1) of a bar system and an electrical conductor (11), said device comprising a bracket (4) connected to said bar and forming a jaw (5, 6), characterized in that 'it comprises a tip (21) provided with a housing (20) for receiving and connecting one end (11a) of said conductor (11), said tip carrying a knife (24) adapted to be received in said jaw ( 5, 6) and to be extracted therefrom. The device of the invention is simple, compact, avoids mechanical stress on the conductor and permanently ensures the electrical insulation of an operator, including during maneuvers.

Description

The invention relates to a connection device and method.

  between a bar of a bar system and an electrical conductor. The invention also relates to an electrical connection assembly between a busbar and an electrical cable. Such an electrical connection assembly can be used in a connection cabinet, for example in a current distribution cabinet between several dwellings located in a street or to connect together several networks for the interconnection of the transformers used for energy distribution to allow, for example,

  maintenance operations on one or more of these trans-

  trainers. By document FR-A-2 731 847, it is known to produce

  a protected connection system on a connection device

  bar type electrical device which comprises a bracket fixed on a bar and designed to receive a terminal of a fuse whose other terminal is received in a second bracket itself connected to a cable. Although having certain advantages when a fuse is to be used, this system is relatively complex and expensive when no fuse is required. In this case, it is imperative to have a removable conductive bar between the jaws of the stirrups, this bar having the function of allowing a circuit break, in particular for an intervention on the conductor, downstream of the connection system or for the decoupling of two networks. The use of two jaws and a knife involves the creation of two electrical contact zones

  removable with higher total electrical resistance

  as much as that of a mass room. There are, at these two contacts, risks of overheating or oxidation and the total size of the system thus produced is relatively large. In addition, the volume occupied by the known device leaves little space for the conductor in the cabinet or the box which contains it, so that the installation of the conductor in the second bracket is delicate and induces

  relatively high mechanical stresses on the conduc-

  tor. Finally, the conductive bar or the fuse of a system of the prior art can be lost on a site; it is then no longer possible to close the electrical circuit in

  good operating and safety conditions.

  It is to these drawbacks that the invention more particularly intends to remedy by proposing an economical, compact electrical connection device whose total resistance is

  lower than that of known devices.

  In this spirit, the invention relates to an electrical connection device between a bar of a bar system and an electrical conductor, this device comprising a stirrup connected to the bar and forming a jaw, characterized in that it comprises a nozzle. provided with a housing for receiving and connecting one end of the conductor, this end piece carrying a knife capable of being received in the jaw and in

be checked out.

  Thanks to the invention, it is no longer necessary to use a conductive bar because the endpiece, which is permanently secured to the end of the conductor and does not risk being lost, fulfills both the function of this bar and that of the bracket for connection to the conductor cable. In addition, the placement of the tip knife in the caliper jaw

  is performed using the natural flexibility of the conduc-

  tor, which can be extracted from the protective sheath of the cable to which it belongs over a long length, because the device of the invention is particularly compact. As a result, the residual stresses on the conductor are low, which

  which improves the service life of the connection thus produced.

  According to a first advantageous aspect of the invention, the knife is arranged on a face of the end piece opposite to a face of this end piece in which is formed an orifice for introducing one end of the conductor into the housing. This geometry makes it easier to insert the knife into the

  jaw or extraction, using flexibility or flexibi-

longitudinal conductor.

  According to another advantageous aspect of the invention, the jaw is made up of two elastic blades, the ends of which are provided with means of electrical insulation between the knife, simply supported on these means, and the blades. This aspect of the invention, which is not compulsory, provides a safety function, insofar as the knife is not electrically connected to the blades which constitute the jaw until it has been positively introduced into this jaw through the isolation means. According to another particularly advantageous aspect of the invention, the jaw and the endpiece are housed in an insulating envelope inside which the endpiece is able to move between a position engaged in the jaw and a position extracted from jaw. This insulating envelope provides a safety function insofar as the constituent parts of the jaw, which are permanently brought to a potential different from the ground, are always isolated from the outside, as is the end piece whose potential varies in

  depending on the position of the knife, especially when maneuvering

operating funds.

  In this case, provision may be made for the envelope to also cover means for fixing and connecting the stirrup to the bar, an orifice for access to these means being provided in this envelope. This aspect of the invention extends the function of

  security to all parties brought to the potential of the bar.

  Advantageously, the envelope includes an access opening to means for fixing the conductor in the end piece. This opening allows the tip to be manipulated during the

  connection of the end-piece and the end of the conductor.

  It is also possible to provide that the stirrup is extended by a tab forming a core for the envelope. This tab can be metallic, which gives it good rigidity.

  According to another advantageous aspect of the invention, the envelope

  loppe carries a controlled locking means of the tip in a position where the knife is extracted from the jaw. Thanks to

  this aspect of the invention, the closure of the electrical link

  that achieved through the jaw and the tip cannot be

  accidental, which provides an additional safety function

  mental. If site security so requires, provision can be made for the locking means to include a padlock or a gripping member standardized and approved by the operator.

energy distribution.

  According to another advantageous aspect of the invention, the end piece is provided with a gripping ring. This gripping ring facilitates the operation of the nozzle, in particular during its extraction from the jaw, in particular inside the envelope. The invention also relates to a connection method which can be implemented with the device of the invention and, more specifically, a method which consists in: - introducing one end of the conductor into a receiving housing provided in an immobilized end piece, removably, relative to a support member; - secure the support member with respect to the bar and - immobilize the end of the conductor in the housing. The invention finally relates to an electrical connection assembly between a busbar and an electrical cable in which each cable conductor is connected to the corresponding bar by means of a device as previously described. This assembly is more economical and more compact than those of the prior art, whereas it induces on the cable

  lower mechanical stresses.

  The invention will be better understood and other advantages thereof will appear more clearly in the light of the

  description which follows of an embodiment of a

  connection device in accordance with its principle, given solely by way of example and with reference to the appended drawings in which: FIG. 1 is a schematic representation of the principle in section of a connection device according to the invention in the open position ; Figure 2 is a view similar to Figure 1 while the device is in the closed position and - Figure 3 is an exploded perspective view of certain components of the device of Figures 1 and 2. In these figures, a bar 1 belonging to a bar system, for example of the type of FR-A-2 715 775, is provided with an orifice 1a for receiving a screw 2 for fixing an element to be brought to the electrical potential of the bar. This element comprises a metal tongue 3 on which is fixed a stirrup 4 comprising two elastic blades 5 and 6 which form a jaw. The free ends of blades 5 and 6 are

  covered by insulating plastic covers 7 and 8.

  One can nevertheless provide a device in which the blades and 6 are not capped with insulating covers. A conductive cable 10, intended to be connected to the various bars of a bar system, comprises several conductors 11, 12 and 13, including the conductor 11 which is provided

to be connected to the bar 1.

  The free end 11a of the conductor 11 is disposed in a receiving housing 20 formed in a ferrule 21 which also carries two screws 22 and 23 for contacting and immobilizing the end 11a in the housing 20. It is possible that the

  device includes a single contact screw or, conversely

re, more than two screws.

  20a denotes the orifice through which the end 11a of the conductor 11 is introduced into the housing 20. The orifice 20a

  is formed on a face 21a, called the rear face, of the end piece 21.

  On a face 21b, opposite to the face 21a and called the front face, the end piece 21 carries a knife 24 whose dimensions are such that it can be introduced between the blades 5 and 6 by exerting a thrust force P. directed towards the bar 1, so that it is immobilized between these blades and brought to the same potential as these.

  The tip 21 and the knife 24 are electrically conductive.

  teurs, so that, in the position shown in Figure 2, the end Ila of the conductor 11 is brought to the electrical potential of the jaws 5 and 6, that is to say to the potential of the bar 1. In this position , conductor 11 is therefore

  electrically connected to bar 1.

  Advantageously, the end piece 21 and the knife 24 are

  formed by a single piece, which improves the robustness

  braids and reduces the electrical resistance of these parts.

  When it is necessary to interrupt the electrical connection made between the bar 1 and the conductor 11, the knife 24 is extracted from the jaws 5 and 6 by means of a

  traction ring 25 in which it is possible to operate

  to slide a finger or a tool. A tensile force T exerted on the ring 25 makes it possible to bring the end piece 21 into the position of FIG. 1 in which the knife 24 is not

  in contact with the blades 5 and 6. Indeed, in this posi-

  tion, the covers 7 and 8 electrically isolate the knife 24 from the blades 5 and 6, even if the knife 24 is in simple support

against the jaw.

  Note that, due to the mounting of the end piece 21 at the end

  mity of the conductor 11, the knife 24 is "captive" in the sense that it remains at the end of the conductor in the open position or

device closed.

  According to an advantageous but not compulsory aspect of the invention, the ring 25 is retractable, in the sense that it can slide in grooves 26 formed on the lateral faces of the end piece 21, which allows it to be plated on the upper face of this nozzle when it is not to be used,

as shown in figure 2.

  In this position, the electrical connection between the bar 1 and the conductor 11 is therefore interrupted and it is possible for an operator to intervene on the circuit supplied with the

cable 10.

  The device of the invention is particularly compact, so that the length L over which the protective sheath of the cable 10 can be eliminated around the conductors 11 and the like is relatively long, for example of the order of at 50 cm, so that the movements of the knife 4 relative to the jaw formed of the blades 5 and 6 are possible thanks to the flexibility or longitudinal flexibility of the conductor 11. Thus, the stresses exerted on this conductor and the busbar are distributed over the length L, so they

are weak.

  An insulating envelope 30 is provided around the stirrup 4 and the end piece 21, this envelope being dimensioned to allow the release of the knife 24 relative to the blades 5 and 6. This envelope 30 isolates the elements brought to the potential of the bar 1 compared to the external environment, which avoids short circuits and provides a safety function

to the device of the invention.

  This cap includes a first opening 31 through which the conductor 11 passes. The opening 31 is of elongated shape so as to allow the displacement of the end piece 21

  between the positions of Figures 1 and 2.

  The envelope 31 also includes a second opening 32, formed in a face perpendicular to that which includes the opening 31, and which allows an operator to access the screws 22 and 23 for immobilizing the end 11a of the conductor 11 inside the housing 20. It is also possible to access the ring 25 through this opening 32 to exert the tensile force T. Near the opening 32, the casing 30 also includes a transparent part 33 forming a window which allows an operator to view the relative position of the knife 24

  and the jaw formed by blades 5 and 6.

  The envelope 30 further comprises an extension 34 which surrounds the screw 2, so that this screw, which is brought to the potential of the bar 1, is also electrically insulated from the outside. An orifice 35 is provided in

  extension 34, in line with screw 2, to allow intro-

  duction of an operating key for this screw, in particular

  for the installation of the device or its disassembly.

  The tongue 3 is surrounded by the bottom 36 of the envelope of which it constitutes, in fact, a frame. Thus, the tongue 3, which is metallic, gives good rigidity to the casing 30 and in particular to the bottom 36 against which the end piece 21 comes to rest in the position of FIG. 2. The fact that the tongue 3 is embedded in the bottom 36 of the casing 30 guarantees its electrical insulation from the outside and, in particular, from the neighboring bars of the bar device. A locking pin 37 is provided on one of the side walls of the casing 30, so as to maintain

  the nozzle 21 in its position in FIG. 1. Thus, the introduc-

  tion of the knife 24 in the jaw formed by the blades 5 and 6 is

  locked, unless pin 37 is removed voluntarily

  rement of the path of the nozzle 21. Closing the circuit requires a conscious operation of the pin 37, which

  avoids any risk of accidental closure. We can, in particular-

  ment, provide that the pin 37 is loaded elastically towards a locking position of the end piece 31, so that the end piece is blocked as soon as it has reached its position of the

figure 1.

  According to a variant not shown of the invention, the function of the pin 37 can be fulfilled by a tongue

  elastic formed on an inner face of the envelope 30.

  Other locking means can be envisaged.

  Given the structure of the device of the invention, the end 11a of the conductor 11 can be introduced into the housing 20 of the end piece 21 while the latter is in position in the jaw formed by the blades 5 and 6. L caliper 4 is then fixed on the bar 1 by means of the screw 2 while the screws 22 and 23 are not tightened, which allows the end 11a of the conductor to be positioned without constraint in the housing 20. The screws 22 and 23 are then tightened. Thus, there is no residual mechanical stress, on the conductor 11 or on the busbar, which would result from the installation of the device. An electrical connection assembly between the cable 10 and a busbar comprising several bars comprises a device as previously described for each conductor

11, 12 or 13.

Claims (10)

  1. Device for electrical connection between a bar (1) of a bar system and an electrical conductor, said device comprising a stirrup (4) connected to said bar and forming a jaw, characterized in that it comprises a nozzle ( 21) provided with a housing (20) for receiving and connecting an end (11a) of said conductor (11), said end piece carrying a knife (24) capable of being received in said   jaw (5, 6) and to be extracted therefrom.   2. Connection device according to claim 1, characterized in that said knife (24) is disposed on a face (21b) of said end piece opposite to a face (21a) of said end piece in which is formed an orifice (20a) for introduction from the end (11a) of said conductor (11) in said housing (20).   3. Connection device according to one of the claims   tions 1 or 2, characterized in that said jaw consists of two elastic blades (5, 6), the ends of which are provided with electrical insulation means (7, 8) between said knife (24) resting simply on said means and said blades.   4. Connection device according to one of the claims   1 to 3, characterized in that said jaw (5, 6) and said tip (21) are housed in an insulating envelope (30) inside which said tip is able to move between a position engaged in said jaw and a   position extracted from said jaw.   5. Connection device according to claim 4, characterized in that said covering cap (30) also means (2) for fixing and connecting said stirrup (4) on said bar (1), an orifice (35) of access to these means   being provided in said envelope.   6. Connection device according to one of the claims.   tions 4 or 5, characterized in that said envelope (30) comprises an opening (32) for access to means (22, 23) for   fixing said conductor (11) in said end piece (21).   7. Connection device according to one of the claims   tions 4 to 6, characterized in that said stirrup (4) extends   by a tab (3) forming a core for said envelope (30).   8. Connection device according to one of the claims   tions 4 to 7, characterized in that said envelope (30) carries a means (37) for controlled locking of said tip (21) in a position where said knife (24) is extracted from said jaw (5, 6).   9. Connection device according to one of the claims   previous operations, characterized in that said end piece (21) is   provided with a gripping ring (25).   10. Electrical connection assembly between a busbar and an electrical cable (10), characterized in that each conductor (11, 12, 13) of said cable is connected to a corresponding bar (1) by means of a device ( 2-37)   according to one of the preceding claims.