FR2497392A1 - ELECTRO-TRACTOR CABLE - Google Patents

Abstract

THE INVENTION CONCERNS AN ELECTRO-TRACTOR CABLE 5 INCLUDING TWO COAXIAL LAYERS 1, 3 OF STEEL STRANDS, MECHANICALLY CONNECTED TO A MECHANICAL ANCHORING TERMINAL 6. THESE BOTTOMS ARE FURTHER ELECTRICALLY INSULATED AND CONNECTED TO CONDUCTORS 15 OF AN ELECTRIC CABLE 7 EXTENDING CABLE 5 BEYOND TERMINAL 6. BABIES 1, 3 THUS ENSURE MECHANICAL RESISTANCE TO THE TENSILE STRENGTHS APPLIED TO THE CABLE 5 AND THE TRANSMISSION OF ELECTRIC CURRENTS CARRYING ENERGY OR INFORMATION FROM ONE END OF THE CABLE TO ANOTHER. APPLICATION TO THE BUILDING OF HIGH ENDURANCE AND SMALL DIAMETER ELECTRO-TRACTOR CABLES.

Description

The technical sector of the invention is that

electro-tractor cables.

  It is known that such cables have a dual function

  tion. On the one hand, they support a pulling force which is applied at both ends or when passing over pulleys or drums; on the other hand, they transmit electrical energy either to provide power to an apparatus located at one end, or to convey information in one direction or the other. For high performance cables and in

  the current state of the art, each of these two functions

  tions is fulfilled by a component of the cable of different type. Good tensile strength is ensured by an armor or sheet consisting of metal threads (steel, bronze) or natural fibers (hemp, shackle) or synthetic (glass, aramid). Good electrical conductivity is obtained with copper or aluminum wires or braids. Also used for the transmission of information, optical fibers (glass, silica) relayed at their ends by opto-electronic couplers. Metal braids also provide a shielding conductors vis-à-vis

  electromagnetic fields parasitic. Others

  Plastic insulators provide electrical insulation, dielectric properties, corrosion resistance and sealing required for different applications. Finally, the electro-tractors cables are equipped at their two ends with mechanical fasteners ("socks", ends) and electrical connectors, possibly associated with electrical connectors.

opto-electronic couplers.

  The known electrotractor cables present

disadvantages.

  During their use, the electro-tractive cables are subjected, in addition to the nominal tensile stress, to mechanical stresses that can be extremely severe: passage on pulleys or drums creating tensions and flexions alternated in several directions crushing

  on storage drums, pull-ups, vibra-

  traction or bending. The known electro-trapping cables have a very heterogeneous constitution and generally without perfect axial symmetry. If the metal components offer accuracies on the order of one hundredth of a millimeter in diameter, 2F plastic components are at best dimensioned to one tenth of a millimeter. As a result, the layers of yarn or fibers work in poor conditions and, consequently, poorly protect copper or aluminum conductors. The various metallic threads stretch, form loops and cut. Cut steel wires pierce sheaths

intended for sealing.

  Consequently, it is recognized that electro-tractive cables never have a great

endurance.

  However, it is not always possible to separate the two functions into two separate cables: an electrical cable and a traction cable. In many applications, the two cables must be very close to each other and, whether placed in the air or immersed, the risk of entanglement is excessive, especially in cases where the winds occur.

or the currents.

  On the other hand, in many cases, cables

  electro-tractors are used immersed either static-

  towing and they are thus subject to currents. Hydrodynamic resistance, which is the main cause of the tensile stress in these cables, is proportional to their diameter and it is found that it is often too high for

known cables.

  The invention aims to create an electro-tractor cable that does not have the disadvantages mexipenés and is distinguished by great endurance

  mechanical and low hydrodynamic resistance.

  The subject of the invention is therefore an electro-tractor cable designed to transmit mechanical tensile stresses and electric currents and comprising at least one sheet of wire (which can be wired in a "strand") / which gives it its mechanical strength vis-à-vis to said tensile forces and is mechanically connected at each end of the cable to a terminal end

  anchor. According to the invention, such a cable is characterized

  rised by the fact that each sheet of threads

  firm is electrically insulated, that its mechanical connection respects its electrical isolation and that it can

  to convey an electric current, being electrically connected

  at each end of the cable, to a driver

  electrical input or output of said electric current.

  Thus, in a cable according to the invention, it is the same constituent elements of the cable, namely the plies of metal son (for example steel) it contains, which fulfill the dual function of the cable: withstand the tensile force and transmit the electric current. Special copper or aluminum conductors therefore become useless for carrying the electric current that the cable must carry. The suppression of these conductors results in a cable of great endurance, because of its homogeneity,

  very compact and compact structure and low cost.

  The use of the cable according to the invention imposes a condition. Electro-tractor cables

  known generally include a large number of conductive

  copper wires insulated from each other to fulfill distinct functions,

  electrical, the other transmission of various signals.

  With only two layers of threads. or little more, it is necessary, to ensure these multiple functions, to use, at both ends of the cable, equipment

  electronic sequential logic or multiplexing.

  But these techniques are now well known.

  The electrical conductibility of steel, about ten times lower than that of copper, is not a disadvantage, because we have in the cable a section of steel much more than ten times greater than that which one would have with copper conductors. As already mentioned, it is important in the electro-tractor cable according to the invention that the mechanical fasteners required at its ends provide electrical separation between the various conductive layers of the cable, furthermore isolated by means of layers of insulating material along the entire length thereof. In the case of a cable comprising one or more plies whose mechanical connection is effected by jamming son or self-tightening of the ends of the metal strands / / between the internal surface of conical shape that offers the end terminal anchor and a central conical piece engaged

  by force, it is appropriate for the sheet or sheets to be

  In this connection, each sheet is electrically insulated and the ends of its strands or strands are inserted between a conductive piece in the form of a male cone and an insulating piece. female cone shape, the corresponding electrical connection conductor (which ensures the input or the output of the current) being connected

to said conductive part.

  In a particular embodiment, a

  cable according to the invention then comprises two cylindrical sheets

  coaxial driques of metal wires, insulated

  of each other, each of which is mechani-

  electrically at each end of the cable by a

  link assembly comprising from outside to inside

  the mechanical anchoring end, a first insulating conical bushing, the end of the outer sheet stripped and deployed in cone, a conductive conical bushing, a second insulating conical bushing, the end of the inner sheet also stripped and deployed at supper, and a conductive cone constituted by the aforementioned eentrale conical piece, the two corresponding electrical connection conductors being respectively connected to said conductive conical bush and to said piece

central conic.

  In a first variant of a mechanical and electrical connection assembly of the cable, it is not necessary to use conical self-tightening bushings, but the end of each sheet of wire of the cable is crimped or welded a ring which provides a connection between the wires of the web and to which the corresponding electrical connecting conductor is connected and, in view of the mechanical connection of the cable, the wires, which are open and formed in hooks, are trapped in a bonded insulating material

at the end anchor.

  In another variant embodiment, the arrangement

  The mechanical connection is distinct from the electrical connection arrangement. The ends of the wires of the cable are connected only electrically and, in view of its mechanical connection, the cable is surrounded over a great length by large helically preformed metal wires and attached in the end anchor by wedging between the surface internal conical shape provided by said tip and a central conical piece

engaged by force.

  Preferably, the conductor or conductors for electrical connection to the sheet or son of the target son are derived from an electric cable extending the electro-tractor cable and mechanically fixed to the terminal anchor end. In the case where the cable must transmit a very high information rate, for example for television images, conductive sheets of large diameter are not suitable. The characteristic impedance of the cable, which contains relatively little material

  dielectric, is low and the attenuation would be excessive.

  For such use, the cable is advantageously completed by one or more optical fibers contained within a sheath. The cable may then comprise axially an optical cable with one or more fibers that coaxially crosses the central conical part possibly used and extend in said cable

  by another optical cable, with interpolation

  of an optical coupler, either by

  with an optocoupler

  eledtraUque housed in the terminal end.

  The following description, with regard to the

  single plate of attached drawings as an example nor.

  limiting, will allow a good understanding of how the present invention can be put into practice, while

  indicating multiple possible variants.

  FIG. 1 represents a cross section of a cfble according to the invention in one embodiment

prefer.

  FIG. 2 represents in longitudinal section, on a scale twice as small, a mechanical end of this cable, also in accordance with the invention and in a

preferred embodiment.

  The cable 5 shown comprises, from the center to the periphery, an armor or inner ply 1 consisting for example of 7 strands of each 19 son galvanized steel, stainless steel or bronze, an insulation layer 2 of plastic such as polyethylene, polypropylene, PVC, polyurethane, polytetrafluoroethylene, etc., an armor or outer ply 3 consisting for example of 25 strands each of 19 metal wires, as above but less coarse, and an outer sheath 4 insulating and protective plastic, as above. In the case shown, the cross-sectional areas of the two plies are equal, so that the latter offer substantially the same tensile strength and the same electrical conductance. The two plies 1 and 3 are preferably assembled in helices in opposite directions, so that a tensile force applied to the cable 5 is not translated.

  not by a torsion torque ("anti-gyratory" cable).

  If the cable is to be immersed, the outer sheath 4 is preferably sealed to retain in this case its

insulation qualities.

  If it is to be submerged at sea, the cable 5 may be limited to the inner ply 1 and the insulating layer 2, the electrical return being made by seawater, usingconsolidated electrodes. In contrast, the inner ply 1 may be replaced at least partially by single conductors, coaxials, pairs or quads,

assembled in various ways.

  An interesting provision is to replace the central strand the inner web 1 by an optical cable lb. It may comprise one or more fibers separated optically, each forming a helix and freely sliding inside a sheath, to support without stress the elongations and flexions of the entire cable. A cable 5 thus formed, with optical fibers in the center, can withstand tensile stresses and stresses.

  important mechanical, anti-inflammatory, and trans-

  put electric power and low frequency information through its two layers of strands 1 and 3 and frequency-based and high-frequency information

  in both directions by its axial optical fibers.

  FIG. 2 shows the connection assembly placed at one end of the cable 5 to ensure the connection

  mechanical and electrical connection.

  The cable 5 is engaged in a terminal end 6 to which it is attached, as will be explained, in order to apply the tensile force of the cable to a structure or a vehicle. At the other end of the tip 6 comes an extension cable 7 electric or opto-electric, which allows to transmit the electrical energy or signals that emits or receives a device supported by the

structure or the vehicle.

  The tip 6, which provides the mechanical connection of the cable 5, is fixed to the structure or the vehicle by screwing, either directly or preferably in a manner articulated by means of two screws bearing in cells 8 located diametrically on the tip, or by

  via a cardan ring.

  In the example shown in Figure 2, the strands or the son of the plies 1 and 3, denuded over a certain length, are attached to the tip 6 by clamping between two ends in one arrangement. known; however, according to a particular feature of the invention, they are not all clamped to the same potential as the metal mass of the tip 6, but

  on the contrary each sheet remains isolated.

  The body of the endpiece 6 constitutes a female center in which is threaded a conical insulating bush 9 of hard plastic material such as oue "RILSAN", "NYLON" technique "HOSTAFORM", "DELP2IN" tc. The holding of this sleeve in the core can be improved by bonding or by striation of the surface of the crone, the outer ply 3 is clamped between this supper

  female thus isolated and a conical joint sleeve 10/11.

  The composite sleeve is constituted by a metal sleeve 10, preferably made of bronze, in which is threaded a sleeve of hard plastic material 11. The holding of the plastic sleeve in the metal sleeve is provided by the pressure due to depression; it is possibly improved by gluing or by streaking the

  inner surface of the metal sleeve 10.

  The inner ply 1 is clamped between the mixed sleeve 10/11 and a male 12 metal cone, preferably bronze. This cable may comprise an axial channel for passing either an optical cable lb or the central wire strand 1a of the cable. In the latter case, the cene 12 has one or two slots 13 to ensure

self-tightening of the central strand.

  The mounting operation of a mechanical connection endpiece 6 at each end of a cable 5 takes place from

  preferably as follows.

  The cable is stripped on the desired lengths

  of its outer and inner insulation sheaths 4 and 2.

  The tip 6, previously internally equipped with the insulating sleeve 9, is threaded onto the end of the cable. The assembly is held vertical as shown in Figure 2 and the tip 6 is simply based on the

outer sheath 4 of the cable.

  The various strands of the outer ply 3 are attached to appropriate special tools such as in

  applying a vertical tensile force between the tool

  lage and cable 5 each strand is subjected to the same voltage. The mixed sleeve 10/11 is then threaded between the outer ply 3 and the inner ply 1 and, with the aid of a tube, it is pressed with a mallet inside the outer ply 3 which it applies strongly. against the inner surface forming

female of the mouthpiece 6.

  Then, the cule mule 12 is depressed in the same manner inside the inner ply 1, its strands being held in tension by the special tool, allowing the axial strand 1 or the optical cable 1b to pass through. The mechanical strength of the assembly is tested by unhooking the strands of the special tool and applying the tensile force directly to the mechanical end piece 6, for example by two screws screwed into a

  structure and taking support in the holes 8.

  The electrical or opto-electrical connection of the electro-tractor cable 5 is carried out as follows. The various metal strands are cut flush with the tip 6 and their ends protruding from the various cones are covered with insulating sheaths 14, by

  example in heat-shrinkable material. Prolonged cable

  7 may be an existing cable comprising insulated conductors 15, insulating and protective sleeves 16 and 18 and possibly a tensile holding braid 17, or a cable of the same type manufactured especially during assembly, in particular using heat shrink tubing. In the case where the electrotractor cable 5 comprises a central optical cable lb, it can be continued in the extension cable 7 designed specifically for this purpose, as shown, or terminated by an opto-electronic coupler housed in the mechanical endpiece. 6 and connected to several electrical conductors of the 7o extender

  4 An insulating washer 20 and a metal washer

  tsolee on its shoulder 22 /, borehole-e holes nh-obre vouiu, are strung on the ends of the strands of the sheets 1 and 3 previously insulated and conductors 15 preelement

stripped at their ends.

  The conductors 15 are brazed in one of the holes arranged at the edge of the metal part 10 of the composite sleeve, the others in holes similarly arranged in the male cone 12, so that a low resistance electrical continuity is achieved.

  on the one hand between the inner layer 1 of the electronic cable

  tractor 5 and one or more conductors 15 of the extension cable 7, on the other hand between the outer ply 3 and

  one or more other drivers 15.

  The wiring being thus made, a connector 22 is screwed into the endpiece 6 to press the metal washer 21 by its central shoulder on the male cne 12 and ensure that the various cnes can not, under the effect of shocks or vibrations, move away from each other and release the cable strands. In order to pocket a drive in rotation of the washer 21 when the coupling 22 is screwed on, the latter is provided either with a central "screwdriver" pin anchored in a groove of the outer cone 12, or with a lateral lug sliding in a groove arranged in axial direction

in the tapping of the tip 6.

  The seal between the tip 6 and the fitting

  22 can be provided by an O-ring 23.

  If the extension cable 7 has a braid

  traction force 17, it can be connected solidly

  According to a known method, the braid wires are clamped between, on the one hand, a ring 24 and semicircular section surrounding the inner sheath 16 of the extension and, on the other hand, taper 22 and a pressure pin, the tightening being performed by means of a nut 26 screwed

on the fitting 22.

  The assembly of the mechanical and electrical connection assembly being thus completed, two adhesive orifices 28 may be injected with an adhesive material, such as Ariate, to form an insulating coating mass 27 inside the mouthpiece. 6 in order to improve the mechanical strength, ensure the sealing and the protection against corrosion

  and braking the two screw connections.

  At the ends of the electro-tractor cable 5 and the extension cable 7, molded sleeves 29 made of flexible plastic material, such as polyurethane, are advantageously made, according to a known method, to complete the sealing of the cables 5, 7 and mechanical end 6 and protect the cables against the effect of excessive flexic. While retaining the new principle of electric transmission by a metal traction ply, the invention can be implemented in a different way.

  from the one shown on the drawing.

  The various conical bushings and the c8ne mile can be removed; rings are crimped or welded on the various strands of the plies 1 and 3 so as, on the one hand, to make shunts between the strands of the same ply, on the other hand, to ensure electrical continuity with conductors 15 In addition, according to a known arrangement, the wires of each strand are expanded and formed into hooks to bear directly in the mass of adhesive 27. In another variant, the cable 5 is surrounded over a large length by coarse wires preformed helical and contiguous metal, which are attached in the mechanical end 6 by self-tightening between

two cnes such as 6 and 10.

  The extension cable 7 is provided at its other end with an electrical or opto-electronic connector possibly sealed, allowing the target to be connected to a device, a structure or a linked vehicle.

  mechanically at the mechanical end 6.

Claims (7)

  1.- Electro-tractor cable conIU to transmit   mechanical tensile forces and electrical currents   with at least one sheet of metal wires   it is known that its mechanical resistance to said tensile forces and is mechanically connected, at each end of the cable, to a terminal anchor end,   cable characterized by the fact that each sheet of wires -   that it encloses is electrically insulated, that its mechanical connection respects its electrical isolation and that it can convey an electric current, being connected   electrically, at each end of the cable, to a   electric input or output of said electric current.   2.- Electro-tractor cable according to the   cation 1, comprising one or more layers whose connection   its mechanics is effected by jamming the wire ends or the metal strands between the conical inner surface of the end anchor end and a central conical piece engaged by force, characterized in that y1nc4r i qua2 ..   that the sheet or sheets are disposed coaxially in the cable, each sheet is electrically insulated and sonyou that the ends of his / strands are inserted between a conductive part in the form of male cone and a piece   insulation in the form of a female cone, the connecting conductor   its corresponding electrical being connected to said conductive part. 3. - Cable according to claim 2, characterized in that it comprises two plies / coaxial son son electrically insulated from one another, chaclune is connected mechanically and electrically to enaque end of the cable by a set of linkage comprising, from the outside towards the inside, the mechanical anchoring end, a first insulating conical bushing, the end of the outer sheet stripped and deployed in cene, a conductive conical bush, a second insulating conical bushing, the end of the inner sheet also stripped and deployed in a cane, and a conductive cone is formed by the aforementioned central conical piece, the two corresponding electrical connection conductors being respectively connected to said conical bushing   conductive and to said central conical piece.   4. Cable according to claim 1, characterized in that at the end of each sheet of son is crimped or welded a ring which provides an electrical connection between the son of the sheet and to which is connected the electrical connection conductor corresponding and that, in view of the mechanical connection of the cable, the son, ------------ expanded and formed in hooks, are trapped in an insulating material attached to the tip anchor terminal.   5. Cable according to claim 1, characterized in that the ends of its son are connected only electrically and that, for the purpose of its mechanical connection, it is surrounded over a large length by large helically preformed wire son and attached in the end terminal anchoring by wedging between the conical inner surface that provides said endpiece   and a central conical piece engaged by force.   6. Cable according to any one of the claims   1 to 5, characterized by the fact that the   electrical connection are from an electrical cable extending the electro-tractor cable and mechanically at the end anchor.   7. Cable according to claim 6, characterized   in that it comprises axially a transmission cable   optical mission with one or more fibers which coaxially crosses the central conical part possibly used and extends in said electric cable either by another optical cable, with the interposition of an optical coupler, or by electrical conductors, with the interposition of a coupler opto-electronic housed in the terminal end.