Patent Publication Number: US-6712640-B2

Title: Connecting arrangement

Description:
FIELD OF THE INVENTION 
     The invention relates to a connecting arrangement for connecting individual electrical conductors of a multiwire lead to circuit-extending electrical conductors, the said connecting arrangement consisting of an insulating casing which is formed from parts that can be connected to one another, a central aperture being provided and contact elements, which are disposed inside the casing and have insulation-cutting terminals, being provided for contact-making purposes. 
     A connecting arrangement of this kind is used for severable, electrically conductive connection to other electrical consumers in an already existing industrial, electrical supply system. 
     BACKGROUND OF THE INVENTION 
     It is known practice to make electrical contact between electrical conductors by means of the insulation-cutting terminating technique. From DE 196 05 083 A1, a cable-connecting arrangement is known, in which an electrical connection from a subscriber&#39;s lead to a printed-circuit board takes place in a modular casing, this being achieved with the aid of an assembly consisting of a perforated disc, a casing and insulation-cutting terminating contacts and integrated into a modular casing. 
     A disadvantageous consequence in that instance is that, as a rule,.a number of electrical conductors are forced into the insulation-cutting terminals at the same time, it being necessary to overcome major forces for severing the insulation, which forces have to be applied by the user and transmitted to the insulation-cutting terminals via the material. 
     Another known electrical type of connection by means of the so-called “piercing technique”, in which metal points bore through the sheath into the electrically conductive conductor, is also ruled out, since connections of this kind either cannot be applied, or can be applied only under certain conditions, in the industrial environment. 
     SUMMARY OF THE INVENTION 
     The underlying object of the invention is therefore to construct a connecting technique of the initially mentioned type which is cost-effective and can be manipulated quickly, for industrial wiring technology, to the effect that it is possible to make electrical contact with a plurality of electrical conductors in a simple and force-saving working operation by means of insulation-cutting terminals, there being provided, at the same time, the possibility of connection to already existing multiwire leads without interrupting the latter. 
     This object is achieved through the fact that there are provided, in a first part of the casing, contact elements which are disposed in the form of a circle and at intervals and which have insulation-cutting terminals, the apertures of the said insulation-cutting terminals pointing towards the centre of the aperture; that a rotatable, cylindrical insert has a peg on which an eccentric is constructed; that the individual conductors are disposed in the form of a circle round the said insert in the axial direction and are pushed, together, into the aperture in the connecting arrangement; and that, when the peg is rotated, the eccentric exerts a radially acting force on the individual conductors, the latter being forced one after another into the apertures in the insulation-cutting terminals. 
     Whereas, in domestic wiring, work is predominantly carried out with flat-strip cables which are laid under plaster, in industrial wiring technology, use is preferably made of round cables with a number of individual wires, which are predominantly laid in cable ducts or cable shafts. Connection to the said individual wires is, as a rule, possible only at branching points which are provided for that purpose. 
     The advantages achieved by means of the invention consist, in particular, in the fact that it is even possible to carry out, independently of any branching point which has already been provided, electrical connections to an existing round cable which has already been laid and which consists of a number of individual electrical conductors, since the casing, according to the invention, of the connecting arrangement is produced from two parts which can be separated in such a way that an electrical lead which has not been severed can be encompassed and can be connected, in the interior of the casing, to a circuit-extending, branching electrical lead. 
     Also of advantage is the fact that an electrical connection is produced in a problem-free and force-saving manner through the use of an eccentric inside the connecting arrangement, the separated electrical conductors each being forced, one after another, into the cutting edges of insulation-cutting terminating contacts, so that, when severing the insulation, only the force for one electrical conductor at a time is required. 
     In one embodiment, the casing parts are preferably connected with the aid of a so-called “T-groove guide”, however other linear guides may also be employed. 
     In addition, provision is made for implementing the mechanical holding-together of the two casing parts in an advantageous manner, only by means of one further component, a semicircular curved element, which is placed inside the casing in such a way that, although the two casing parts are fixedly connected to one another mechanically, they can nevertheless be detached again. 
     At the same time, the said curved element advantageously serves to hold the contact elements, which have insulation-cutting terminals on one side and, on the other side, connecting ends onto which the electrical conductors leading in or away can be slipped, again by means of slip-on contacts. An advantageous disposition of the electrical conductors in the interior of the casing lies in their peripheral distribution over a semicircle in corresponding clearances in an insert which is cylindrical as a whole and which can be inserted in a central aperture in the casing. 
     The insert represented in the form of embodiment advantageously has an eccentric, onto either side of which a peg is moulded, there being pushed onto each peg rotatable circular ring elements in which the separated electrical conductors are placed in moulded-in clearances. When the insert is pushed into the central aperture, the electrical conductors in the clearances of the circular ring elements have corresponding clearances in a first part of the casing lying opposite them, so that the said electrical conductors pass into the said clearances as soon as the insert has been inserted, and directly adjoin the insulation-cutting terminals. If the eccentric is twisted by rotation of the peg by means of a simple tool, for example a screwdriver, the electrical conductors are progressively forced in an advantageous manner, individually and without the exertion of a great deal of force, into the insulation-cutting terminals which are disposed at intervals and side by side in the form of a ring. 
     In another advantageous form of embodiment, the components required are further reduced, so that an additional reduction in costs and assembly time can be achieved. In this instance, the abovementioned two casing parts have been combined to form a one-piece casing in the form of an axially slit hollow cylinder, which is covered by a circular element serving as a closure. The rotatable insert has been advantageously designed in one piece, so that the circular ring elements, as already described above, have been eliminated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An exemplified embodiment of the invention is represented in the drawings and will be explained in greater detail below. In the said drawings: 
     FIG. 1 shows an exploded perspective drawing of the connecting arrangement, 
     FIG. 2 shows a perspective view of a first casing part, 
     FIG. 3 shows a perspective view of a second casing part, 
     FIG. 4 shows a perspective view of a curved element, 
     FIG. 5 a  shows a perspective view of an insert, 
     FIG. 5 b  shows a perspective view of the insert with individual electrical conductors surrounding it, 
     FIG. 6 shows a plan view of the casing plane of the insulation-cutting terminals with a position of the eccentric in which there is no contact-making between the insulation-cutting terminals and the electrical conductors, 
     FIG. 7 shows a plan view of the casing plane of the insulation-cutting terminals with a position of the eccentric in which there is partial contact-making between the electrical conductors and the insulation-cutting terminals, 
     FIG. 8 shows a perspective axial section through an assembled connecting arrangement, 
     FIG. 9 shows a pulled-apart representation of a variant of the connecting arrangement, viewed from a circular ring element, and 
     FIG. 10 shows another view of the connecting arrangement, viewed from the slit hollow cylinder. 
    
    
     DETAIL DESCRIPTION OF THE INVENTION 
     In FIG. 1, the various components of a connecting arrangement, which can be inserted in one another, are represented in an exploded view. In this figure, it is possible to make out a casing  1  which is formed from two semicircular segments, parts  20 ,  30 , and is designed, as a whole, as a round body, and in the middle of which a central aperture  3  is provided. A cylindrical, rotatable insert  60  can be inserted in the said aperture. 
     Also provided is a semicircular curved element  40 , by means of which the two parts  20 ,  30  are held together mechanically. The said parts  20 ,  30  are not symmetrical but are divided outside their theoretical middle, so that the part  20  reaches slightly beyond the said middle line, whereas the part  30  is of slightly shorter design. At their dividing faces  21 ,  31 , which extend in the axial direction, the segment-like parts have guide elements  22 ,  32  which, in this example, are constructed as a T-groove guide. However, variants of a different kind of guide can also be conceived of. In addition, provision is made (but not shown here) for the guides to be of different construction in order to achieve confusion-proof coding. By means of the said guides, the parts are, first of all, held together against falling apart, however they are still displaceable in relation to one another. In order to avoid displacement, the semicircular curved element  40  is pushed into the central aperture  3 . Under these circumstances, the curved element interlocks the two parts  20 ,  30  and the casing now formed represents a mechanically stable body. 
     FIG. 2 shows the segment-like part  20 , with clearances  23  inside the offset  27  for the individual conductors  11  to be received, which clearances point towards the central aperture. For the purpose of contact-making between the connecting ends  7  (shown in FIG. 8) and a slip-on contact  100  (shown in FIG.  8 ), clearances  24  are moulded in on the inner side of the wall in the axial direction of the part  20 , which clearances combine with clearances  44  in the curved element to form a chamber into which the slip-on contacts with the additional electrical conductors  15  can be pushed. 
     The part  30 , which is represented in FIG. 3, likewise represents a partial circular segment, on each of whose dividing faces  31  there are provided two T-guides  32  which belong to the T-grooves in the part  20 . In that connection, the T-guides are provided, in one case, over the entire dividing face and, in the other, in a shortened form, in a manner corresponding to the shaping of the part  30 . An additional undercut  35  in a partial region of the wall of the part  30 , into which undercut the curved element  40  projects with its sectional faces  45 , diminishes the transmission of force onto the guiding means  22 ,  32 , if an attempt is made to push the joined-together parts  20 ,  30  apart sideways without removing the curved element  40  beforehand. 
     However the curved element  40 , which is shown in FIG. 4, has yet another function, in that the contact elements  5  are disposed and fixed, in the form of a circle, in the depressions  42 . When the curved element is put in, the contact elements are also inserted in the part  20 . In addition, there are moulded into the curved element, in the outer region, clearances  43  which form, in conjunction with the clearances  23  on the inner wall in the part  20 , chambers into which the connecting ends  7  of the contact elements project and into which slip-on contacts with electrical conductors  15  fixed thereto are also introduced and pushed onto the connecting ends  7 . That inner region of the curved element  40  which points into the central aperture  3  additionally has a clearance  43  which represents a prolongation of the clearances  23  moulded into the offset region  27  of the part  20 . The individual conductors  11  are guided, when the insulation-cutting terminals  6  make contact with them, into the said axially coinciding clearances. 
     The cylindrical insert  60 , which is to be inserted, with the circular ring elements  50  disposed thereon, in the central aperture in the casing, is represented in FIG.  5 . The insert consists of the two pegs  61 ,  62  and a moulded-on eccentric ring  63 , and also of two circular ring elements  50  which are identical in their form of embodiment and which are pushed onto the pegs on either side of the eccentric ring and in such a way as to be rotatable independently of the latter. The circular ring elements  50  have, moulded into them peripherally, semicircular clearances  53  which are provided for the purpose of receiving the individual conductors  11 , and also, moulded onto the said segments, noses  52  which engage in corresponding clearances  34  in the part  30  and thus prevent twisting of the circular ring elements after insertion in the central aperture in the casing. 
     After assembly, the peg  61  projects beyond the externally located circular ring element and contains, in this projecting part, two transverse bores  64  which are incorporated crosswise and into which a tool can be introduced in order to rotate the peg with the eccentric ring. Provision is also made for bringing the two circular ring elements into coincidence of their position relative to one another by a catching action, which can be easily overcome in the direction of rotation, between the peg and the circular ring elements. 
     The mode of functioning and operation of the insert  60  with the eccentric ring  63  is represented in FIGS. 6 and 7, namely in the form of a plan view in the region of the insulation-cutting terminals and of the eccentric ring. In the said FIGS., FIG. 6 reproduces the starting position in which the cylindrical insert  60  is fitted with the individual conductors  11 , which are laid in the clearances  53  in the circular ring elements  50 . 
     If the eccentric is rotated, as shown in FIG. 7, the individual conductors  11 , which are initially inserted in the peripheral clearances  53  in the circular ring elements  50 , are moved radially outwards in the direction of the part  20  having the correspondingly associated clearances  23  and also the insulation-cutting terminals  6  contained therein. In the process, the electrical conductors are successively forced between the cutting edges of the insulation-cutting terminals, the insulation being cut and contact-making taking place between the electrical contact and the insulation-cutting terminal. The eccentric is rotated by means of a simple tool, such as a screwdriver for example, which is slipped into the transverse bores which are moulded crosswise into the projecting part of the peg. 
     In the course of the assembly of the connecting arrangement, as has already taken place in FIG. 8, in order to achieve a branching connection to the electrical conductors  15  from or to a multiwire lead which has already been laid, the sheathing  12  is removed at a suitable point in the case of a round cable which, as a rule comprises a number of individual conductors, and the said individual conductors  11  are pulled apart. 
     The casing of the connecting arrangement is disassembled, through the fact that the insert  60  inserted in the central aperture  3 , and also the curved element  40 , are first of all removed and the two parts  20 ,  30  are displaced, counter to one another, in their guides  22 ,  32  until they are separated. The individual conductors  11  are then laid in the coinciding clearances  53  in the circular ring elements  50 , the eccentric  63  being twisted in such a way that its minimal distance from the electrical conductors lies in the region of the clearances  53 , so that the said electrical conductors can be put in without any difficulty in the appropriate manner. The parts  20 ,  30  are then placed round the individual conductors of the round cable and pushed together. 
     The curved element  40 , in which the contact elements are held, is then inserted in the central aperture  3  in order to lock the two parts, and finally the insert  60 , with the individual conductors disposed around it, is pushed into the central aperture in the casing in such a way that the noses  52  on the circular ring elements  50  engage in the clearances  34  in the part  30  and are thus fixed in the casing. Finally, the electrical conductors are forced into the insulation-cutting terminals by putting a tool into the transverse bores  64  in the peg  61  projecting out of the casing and by the twisting of the said peg in relation to the casing as a result of the action, which has been described earlier, of the co-rotating eccentric. In this example, the electrical conductors  15  which are to be branched out of the connecting arrangement will be pushed by means of cable shoes onto the connecting ends  7  of the contact elements  5 , which connecting ends are disposed in chambers. 
     FIGS. 9 and 10 show a variant of the above described connecting arrangement, in which there is shown a first part  20 ′ which is designed as a hollow cylinder and has, for the purpose of inserting the multiwire lead  10 , a longitudinal slit  29 ′, an aperture  3  in which the insert  60 ′ can be inserted, and also a circular ring element  50 ′ which is pushed axially into the part  20 ′ and locked therein. 
     The contact elements  5  are inserted in chambers  24  in a self-retaining manner and so as to point, with their insulation-cutting terminals  6 , towards the centre of the aperture. The circular ring element  50 ′ is provided with a middle bore  51 ′ for receiving the peg  61 ′, and also with clearances  53 ′ into which the individual conductors  11  of the multiwire lead  10  can be placed. The clearances are designed so as to be prolonged by moulded-on portions  54 ′ on both sides, which portions project beyond the outer radius of the circular ring. Projections  55 ′, which are bent over at right angles and can be inserted in corresponding clearances  28 ′ inside the chambers  24 ′ and which give rise to interlocking of the two parts  20 ′ and  50 ′, are provided at the ends of the moulded-on portions. For secure guidance of the individual conductors  11  above the eccentric pressure-applying face of the eccentric  63 ′, the moulded-on portions  54 ′ are designed so as to be prolonged to such an extent, on the side pointing towards the eccentric, that they terminate with the thickness of the disc of the eccentric. The through-aperture  3  through the hollow-cylinder part  20 ′ is formed by two bores  25 ′,  26 ′ which differ in diameter and which form the offset  27 ′. The diameter of the bores  25 ′,  26 ′ is coordinated with the outer diameter of the peg  62 ′ and also of the eccentric  63 ′, whereas the diameter of the peg  61 ′ is coordinated with the bore  51 ′ in the circular ring element  50 ′, so that the bores  25 ′,  26 ′ and  51 ′ simultaneously serve as pivot bearings for the insert  60 ′. The offset serves as a bearing face for the insulation-cutting terminals of the contact elements  5 , which terminals point towards the centre of the aperture. Provided underneath the insulation-cutting terminals are clearances  23 ′ for the individual conductors  11 , into which the latter are inserted when they are forced into the said insulation-cutting terminals  6  when the eccentric  63 ′ is rotated. Assembly takes place in a similar manner to that in the variant previously discussed, in that the sheathing  12  of the multiwire lead  10  is removed at a suitable point, the individual conductors  11  are pulled apart in a fanned-out manner, and the insert  60 ′, with the circular ring element  50 ′ pushed on, is placed in the centre thus produced, the individual conductors being placed in the clearances  53 ′ in the circular ring element. In the process, care must be taken to ensure that the eccentric is disposed with its smallest radial interval in the region of the clearances in the circular ring elements. Since the contact elements  5  are already disposed in the hollow-cylinder part  20 ′, the multiwire lead is inserted, at a region which is still sheathed, in the aperture  3  through the slit  29 ′, and then the combination of individual conductors which have been widened out over the eccentric and the circular ring element is pushed into the aperture in the part  20 ′ as far as the stop. In the process, a closing piece  56 ′ moulded onto the circular ring element closes the slit  29 ′ present in the part  20 ′. A catching action between the part  20 ′ and the circular ring element  50 ′ is provided for in a perceptible and audible manner. As a result of that part of the peg  61 ′ which projects out of the casing which has now been produced being rotated through the fact that a simple tool is placed in one of the transverse bores  64 ′ and rotated in one direction, the individual conductors  11  are forced radially outwards, one after another, into the insulation-cutting terminals  6  of the individual contact elements. An electrical connection between the individual conductors  11  and additional electrical conductors  15  takes place as a result of the pushing of the electrical conductors  15 , which have been provided with slip-on contacts, into the chambers  24 ′ in the hollow-cylinder part  20 ′ and onto those connecting ends  7  of the contact elements  5  which have been bent by 90°. (In that connection, see also FIG. 8.)