Apparatus for making contact with an electrical conductor, and connection or connecting device with an apparatus of this kind

Abstract

An apparatus (1) for making contact with an electrical conductor (10, 20), in particular a cable conductor of a power supply cable, has a connecting body (4) that delimits a receiving space (6) into which the conductor (10, 20) with which contact is to be made can be inserted by way of its end. The apparatus (1) has a contact medium (30) with which electrical contact can be made with the end of the conductor (10, 20) under the action of a contact force. The contact medium (30) has a large number of electrically conductive contact bodies (32) introduced into the receiving space (6) and bearing against one another. At least some of the contact bodies can be brought into electrical contact-making contact with the ends of the conductors (10, 20).

Claims

1. An apparatus for making contact with an electrical cable conductor, the apparatus comprising: a connecting body having a receiving space therein for receiving the cable conductor with the cable being inserted by a first end of the cable conductor into said receiving space; a contact medium capable of making electrical contact with the front end of the cable conductor under a contact force, said contact medium having a plurality of electrically conductive contact bodies introduced into said receiving space and bearing against one another, at least some of said contact bodies being able to be brought into electrical contact-making contact with the front end of the cable conductor; a force storage constantly maintaining the contact force on said contact medium against the front end of the cable connector.

2. An apparatus according to claim 1 wherein the contact force of one said contact bodies is transmitted to at least one of adjacent ones of said contact bodies, the cable conductor or said connecting body.

3. An apparatus according to claim 1 wherein said contact bodies have shapes capable of transmitting contact forces in an essentially direction-independent manner to at least one of adjacent ones of said contact bodies, the cable conductor or said connecting body.

4. An apparatus according to claim 1 wherein at least part of each of the said contact bodies comprises an at least partially curved surface.

5. An apparatus according to claim 4 wherein each said outer surface is at least partially spherical surface.

6. An apparatus according to claim 1 wherein said contact bodies are ball-shaped.

7. An apparatus according to claim 1 wherein said contact bodies have electrically conductive surface coatings having lower contact resistances relative to materials of said contact bodies.

8. An apparatus according to claim 1 wherein said contact medium comprises a pasty mass, said contact bodies being embedded in said pasty mass.

9. An apparatus according to claim 1 wherein a force application element contacts and applies said contact force on said contact medium.

10. An apparatus according to claim 9 wherein a force indicator provides a signal indicating that said force application element has applied an adequate contact force on said contact medium.

11. An apparatus according to claim 1 wherein a fixation device fixes an axial position of the cable conductor in the connecting body.

12. An apparatus according to claim 1 wherein said force storage is resilient.

13. An apparatus for making contact with an electrical cable conductor, the apparatus comprising: a connecting body having a receiving space therein for receiving the cable conductor with the cable being inserted by a first end of the cable conductor into said receiving space; a contact medium capable of making electrical contact with the front end of the cable conductor under a contact force, said contact medium having a plurality of electrically conductive contact bodies introduced into said receiving space and bearing against one another, at least some of said contact bodies being able to be brought into electrical contact-making contact with the front end of the cable conductor; a force application element contacting and applying said contact force on said contact medium; and a force indicator providing a signal indicating that said force application element has applied an adequate contact force on said contact medium.

14. An apparatus according to claim 13 wherein the contact force of one said contact bodies is transmitted to at least one of adjacent ones of said contact bodies, the cable conductor or said connecting body.

15. An apparatus according to claim 13 wherein said contact bodies have shapes capable of transmitting contact forces in an essentially direction-independent manner to at least one of adjacent ones of said contact bodies, the cable conductor or said connecting body.

16. An apparatus according to claim 13 wherein said contact bodies are ball-shaped.

17. An apparatus according to claim 13 wherein said contact bodies have electrically conductive surface coatings having lower contact resistances relative to materials of said contact bodies.

18. An apparatus according to claim 13 wherein said contact medium comprises a pasty mass, said contact bodies being embedded in said pasty mass.

19. A connection, comprising: an electrical cable conductor having a front end and having multiple wires; a connecting body having a receiving space therein receiving said cable conductor with the cable being inserted by said first end of said cable conductor into said receiving space; a contact medium capable of making electrical contact with said front end of said cable conductor under a contact force, said contact medium having a plurality of electrically conductive contact bodies introduced into said receiving space and bearing against one another, at least some of said contact bodies being in electrical contact with said front end of said cable conductor; and an expansion element inserted in said front end of said cable conductor.

20. A connection according to claim 19 wherein said expansion element is inserted centrally into said front end of said cable conductor.

21. A connection according to claim 19 wherein at least part of each of the said contact bodies comprises an at least partially curved surface.

22. A connection according to claim 21 wherein said curved outer surface has a radius of curvature less than 50 percent of said front end of said cable conductor.

23. A connection according to claim 21 wherein said curved outer surface has a radius of curvature less than 40 percent of said front end of said cable conductor.

24. A connection according to claim 21 wherein said curved outer surface has a radius of curvature less than 25 percent of said front end of said cable conductor.

25. A connection according to claim 19 wherein an annular element is mounted in said connecting body against adjacent said front end of said cable conductor, said annular element having an external diameter essentially equal to a clear width of said receiving space and an internal diameter essentially equal to an external diameter of said cable conductor adjacent said front end.

26. An apparatus for making contact with an electrical cable conductor, the apparatus comprising: a connecting body having a receiving space therein for receiving the cable conductor with the cable being inserted by a first end of the cable conductor into said receiving space and having holes therein extending between an outside surface of said connecting body and said receiving space; a contact medium capable of making electrical contact with the front end of the cable conductor under a contact force, said contact medium having a plurality of electrically conductive ball-shaped contact bodies introduced into said receiving space through said holes in said connecting body, said contact medium completely filling said receiving space, said contact bodies bearing against one another, at least some of said contact bodies being able to be brought into electrical contact-making contact with the front end of the cable conductor; and threaded pins threadedly engaged in said holes in said connecting body, closing said holes and applying forces on said contact medium to produce the contact force.

27. An apparatus according to claim 26 wherein a resilient force storage is in contact with and maintains the contact force of said contact medium against the front end of the cable conductor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Referring to the drawings that form a part of this disclosure:

(2) FIG. 1 is a side view in section of an apparatus according to a first exemplary embodiment of the invention;

(3) FIG. 2 is a side view in section of the apparatus of the first exemplary embodiment rotated 90 about the longitudinal axis of the apparatus;

(4) FIG. 3 is a side view in section of an apparatus according to a second exemplary embodiment of the invention;

(5) FIG. 4 is a side view in section of an apparatus according to a third exemplary embodiment of the invention;

(6) FIG. 5 is a side view in section of an apparatus according to a fourth exemplary embodiment of the invention;

(7) FIG. 6 is a side view in section of an apparatus according to a fifth exemplary embodiment of the invention;

(8) FIG. 7 is a side view in section of an apparatus according to a sixth exemplary embodiment of the invention; and

(9) FIG. 8 is a side view in section of an apparatus according to a seventh exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(10) FIG. 1 shows a longitudinal section through a first exemplary embodiment of an apparatus 1 according to the invention for making contact with a multi-wire electrical conductor 10. In this case the apparatus connects a first multi-wire electrical conductor 10 to a second multi-wire electrical conductor 20. The cable conductors 10, 20 are parts of a first power supply cable 12 and a second power supply cable 22, respectively. The two conductors 10, 20 lie in the region of the apparatus 1 coaxial to the longitudinal axis 2 of the apparatus 1. FIG. 2 also shows a longitudinal section through the apparatus 1, in which the apparatus 1 is rotated 90 about the longitudinal axis 2.

(11) The first exemplary embodiment serves to connect conductors 10, 20 having the same cross section and uses as an external contact system the tubular connecting body 4 which, like a normal press connector, is slid onto the prepared ends of the conductors 10, 20 at the left and right and is pressed in, for example, with hydraulic tools. In a similar way to the case of a conventional press connector, with appropriate conductivity the connecting body 4 can also be used for the power transmission of the bare conductor wires of the two conductors 10, 20, which conductor wires are contacted on the surface. Because possible insulating layers were not removed from the individual wires and only the two outer layers are, from experience, involved in the transport of current in the case of multilayer cables, this contact alone does not establish an adequate electrical contact. The pressing then ensures in particular that the two ends of the conductors 10, 20 are fixed on the connecting body 4 and are then connected to one another in a mechanically stable manner.

(12) Because the front ends 14, 24 of the conductors 10, 20 are also radially clamped and can only move slightly or not at all in the longitudinal direction, a receiving space 6 is delimited axially by the two conductors 10, 20 and radially by the connecting body 4. Contact bodies 32 are introduced into that receiving space and are embedded in a pasty mass 34. Together the contact bodies and pasty mass form the contact medium 30 of the apparatus 1, which contact medium is only partially depicted for reasons of clarity.

(13) The contact bodies 32 are formed by balls made from copper, have a uniform size and are covered with a 3 m to 5 m thick layer of tin. The diameter of the balls is more than 10% and less than 100% of the extension of the narrow side of a wire of the conductor 10, 20, in particular more than 15% and less than 90% and preferably more than 20% and less than 85%. The pasty mass 34 can comprise a silicone gel or another paste with suitable viscosity.

(14) After the introduction of an adequate quantity of the contact medium 30, for example via the two first threaded openings 16 abutting the receiving space 6 and arranged one behind the other along the longitudinal axis 2, a threaded pin or a tear-off screw acting as a force application element 18 is screwed into these threaded openings 16 and the receiving space 6 is then closed, and the contact medium 30 is placed under pressure with further screwing in of the screws.

(15) The apparatus also has two force storages 28, which each have a set of disk springs 38 and are inserted into the connecting body 4 radially at sides axially opposite one another. The force storages 28 are screwed into corresponding second threaded holes 26 and then stuck therein. The two force application elements 18 are screwed into the connecting body 4 and tightened until force indicators in the form of signal elements 36 on the force storages 28 indicate that the contact medium 30 is adequately tensioned. The force storages 28 are dimensioned such that they maintain the minimum necessary holding force even if, due to thermal load changes and constant relaxation losses, the volume between the two conductors 10, 20 were to expand, or the ends of the two conductors 10, 20 were to nevertheless move a little.

(16) FIG. 3 shows a longitudinal section through a second exemplary embodiment of the invention with an apparatus 101, in which a one-part tube is pushed as a connecting body 104 over the ends of the two different or cross-sectionally identical conductors 110, 120. The two conductors 110, 120 are then fixed by the axially outermost holding screws 142 to the connecting body 104, which screws form part of a fixing device of the apparatus 301. The central part 144 with the force storage means 128 or spring sets 138 is already installed in the connecting body 104 and fixed there axially and radially at the center. With such design, a portion of the current load can flow over the holding screws 142 and the connecting body 104. However, this flow is not absolutely necessary and permits more compact designs of the apparatus 101. An advantage of this exemplary embodiment is that all connections can be tightened with customary tools for attachment devices. No special tools are required.

(17) The preferably ball-shaped contact bodies 132 are introduced via the still open holes 116 for the force application elements 118, until the receiving space 106 between the conductors 110, 120 is completely filled. The contact force is applied by the force application elements 118, which are formed, for example, by threaded pins and which are finally screwed into the holes 116 and tightened, until no screw protrusion can be seen.

(18) The centering screw 146 in the center of the connecting body 104 fixes the pre-tensioned force storages 128 with its sets of disk springs 138. By torque-controlled tightening of the total of four force application elements 118 of the dimension M12, the contact bodies 132 are placed under pressure and the force storage 128 is pre-tensioned.

(19) The connecting body 104 can be formed by a tube or by connectable half shells. The half shells can be placed around the conductors 110, 120 and clamped by a suitable device relative to one another and to the conductors 110, 120.

(20) An annular element 148 is mounted on each of the two conductors 110, 120 at their front ends. The external diameter of each annular element 148 is adapted to the receiving space 106 of the connecting body 104, and in particular essentially corresponds to the clear width of the receiving space 106 of the connecting body 104. The internal diameter of each annular element 148 is adapted to the external diameter of the conductor 110, 120 with which contact is to be made, in particular essentially corresponds to the external diameter of the conductor 110, 120 with which contact is to be made. The conductors 110, 120 are then centered in the connecting body 104. Their circumferential contour is ensured and is preferably circular. The annular elements 148 extend over the front end of the respective conductor 110, 120, while forming an annular bar 152 directed radially inwards, forming a stop when the annular element 148 is slid onto the conductor 110, 120.

(21) An expansion element 150 is inserted centrally into the front end of each of the two conductors 110, 120. Each expansion element has several sections, at least a portion of which are frusto-conical and can be detached from one another in a preferably tool-free manner. The contour of the depicted longitudinal section through the expansion element 150 is also conical, so that the associated conductor 110, 120 is expanded all the more and is pressed into contact with the inside of the annular element 148 the further the expansion element 150 is introduced into the conductor 110, 120.

(22) FIG. 4 shows a longitudinal section through a third exemplary embodiment of the invention with an apparatus 201. The installation of apparatus 201 is simplified in that a second part 204b, in particular a second half, of the two-part or multiple-part tubular connecting body 204 can be taken off a first part 204a and mounted on the first part 204a again and fixed there, for example, with a ring, once the connecting body 204 is in the right position relative to the conductors 210, 220. Also possible is for both sides of the connecting body 204 to be formed in such a way.

(23) For the installation, one side of the connecting body 204 is pushed onto the end of the first conductor 210 and fixed there by the holding screws 242. In the axial direction, two or more rows of holding screws 242, which are preferably equidistantly spaced apart in the circumferential direction, can be provided. The holding screws 242 of adjacent rows can be offset relative to one another in the circumferential direction, so that several and preferably all individual wires of the conductors 210, 220 are clamped. The end of the second conductor 220 can then be inserted into the open half shell on the other side of the connecting body 204 and, in particular, must not be pushed in in the longitudinal direction. This arrangement is advantageous because an axial movement of such cable conductors is only possible by application of significant forces due to their large dimensions.

(24) FIG. 5 shows a longitudinal section through a fourth exemplary embodiment of the invention, with an apparatus 301, in which a first part 304a of the connecting body is mounted on an end of each conductor 310, 320. The two first parts 304a are then connected with a connecting element 340. The contact bodies 332 are introduced and compressed and placed under pressure by screwing in of the force application elements 318. The ensuing pre-tensioning on the force storage means 328 can be measured from outside the apparatus 301 by the axial position of pin-shaped signal elements 354. Signal elements 354 are arranged in the force storage 328 and extend radially outwards and penetrate radial holes in the connecting element 340. When the conical sections of the force storage move, for example, axially to the center of the apparatus 301, the signal element 354 is carried along. At the axial position of the signal element 354. From outside the apparatus 301 the extent the force storage 328 is pre-tensioned can be measured.

(25) In one modified embodiment, the radial hole in the connecting element 340 for the passage of the signal element 354 can be only insignificantly larger than the dimension of the signal element 354. No axial relative movement of the signal element 354 relative to the connecting element 340 is then possible. Instead, the receiving opening for the signal element 354 provided in the force storage 328 has an angular face so that, in the case of an axial relative movement of the force storage 328 relative to the connecting element 340, the signal element 354 slides along the angular face and is then moved radially in the radial hole. The pre-tensioning of the force storage means 328 can then be measured from outside the apparatus 301 by the radial position of the signal element 354. For example, the signal element 354 is only visible or is flush with the connecting element 340 when the force storage 328 is adequately pre-tensioned and the contact force is thus adequate. The signal element 354 can be able to be moved axially and/or radially under a spring force load to eliminate the influence of the weight force, for example.

(26) FIG. 6 shows a longitudinal section through a similarly three-part fifth exemplary embodiment of the invention with an apparatus 401. The two first parts 404a of the connecting body are also each mounted on an end of a conductor 410, 420. These two first parts 404a are then connected with a multi-part connecting element 440, for example by two half shells that can be screwed to one another. A holding body of the force storage 428 surrounding the spring elements can project into the two first parts 404a of the connecting body axially by its two axial end sections opposite one another.

(27) In particular, each axial end section can have an external thread to be able to be screwed into the two first parts 404a, and can form an axial stop for the ends of the two conductors 410, 420 by an end inside taper section.

(28) One advantage of the described three-part exemplary embodiments is that both conductor ends can be mounted in advance individually and independently of one another. The pushing on of the two ends of the apparatus 301,401 assigned to the conductors 310, 410, 320, 420 is then very easily achievable. In particular, the associated cables do not have to be moved for this purpose. When the central connecting element 340, 440 is screwed on, the conductors 310, 410, 320, 420 are centered and the front sides are firmly clamped.

(29) The two ends then mounted in advance are moved into a coaxial position and electrically and mechanically connected with the half shells. The half shells can have more than two segments. The form fitting for the mechanical and electrical connection can take place by a thread or circumferential grooves. The form-fitting connection of the individual parts of the connection improves the mechanical strength. The minimizing of remaining cavities increases the mass percentage and improves the low-loss power transmission.

(30) FIG. 7 shows a longitudinal section through a sixth exemplary embodiment of the invention with an apparatus 501, which can be used for a plug-in system with lamellar contacts. In the case of such a pluggable connection part, generally no significant demands are made with respect to the axial tensile loading capacity of the conductor connection. The conductor front surface is prepared and the connecting or connection body 504 is pushed on. The connecting body 504 has a circumferential groove on the outside, into which a contact lamella 556 is inserted.

(31) The connecting body 504 is filled with the contact medium 530 and pushed onto the end of the conductor 510 and mechanically fixed on the conductor end by the holding screws 542. A conical surface 558 on the connecting body 504 realizes the centering and the sealing of the edge of the front surface of the conductor 510. The contact force is then pre-tensioned by the force storage 528, which can be screwed into the connecting body 504 on the front side opposite the conductor 510.

(32) FIG. 8 shows a longitudinal section through a seventh exemplary embodiment of the invention with an apparatus 601, which can be used, for example, for screw connection bolts on cable terminations and can be constructed according to the same design principle as the previously described apparatuses. The end section for receiving the connection fitting of an open wire or the screw connection to a busbar system can be designed, depending on the application, for example as massive round bolts, as a flat rectangular connecting lug with holes, oras depicted with dashed lines in FIG. 8as a cable shoe 660. At the cable conductor end, a screwed embodiment with holding screws 642 is depicted by way of an example, with compressed embodiments or other embodiments of the connection types also being possible.

(33) The force storage 628 can be screwed into a hole in the connecting body 604. The hole creates an acute angle with the longitudinal axis of the apparatus 601 of preferably more than 15 and less than 80, in particular more than 20 and less than 65, and preferably more than 30 and less than 45.

(34) While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the claims.