FR2535513A1 - Self-supporting cable comprising a bundle of insulated conductors or of tubes and in parallel a partially stripped carrier wire, and die for the jacketing of such a cable. - Google Patents

Abstract

The self-supporting cable is composed of a bundle 1 of insulated conductors and/or optical fibres and/or of fluid conductor tubes, of a carrier wire 2 parallel with the bundle, and of an extruded tubular jacket 3 which surrounds the bundle 1 and comprises spaced-apart projections 4 forming straps around the wire 2. This structure is obtained by extrusion with a die comprising two half-dies, the first die being conventional and assigned to the bundle 1 while the second die, assigned to the wire 2, comprises a valve with a tubular stem in which the wire 2 passes, and with a head which can move between a rear position where the extrusion end-fitting is blocked off and a forward position where the end-fitting is clear. An actuating-cylinder control, acting on the valve stem and synchronised to the haul-off of the jacketed cable, permits the spaced-apart extrusion of the projections 4.

Description

The invention relates to a self-supporting cable comparing nant, in addition to a bundle of insulated conductors and / or optical fibers and / or fluid conductive tubes 91n partially stripped parallel carrying cable. The invention is furthermore related to a die for sheathing of such a cable
Cables which are used to supply or control mobile devices over shorter or longer distances, such as hoists, conveyors, drag lifts, require only one rope capable of supporting the load of the cable and to prevent the lengthening under load from breaking the conductors of the cable, or being added to this for supporters It is undesirable that the 41st rope is placed in the sheath of the cable with the bundle of conductors because both the mechanical anchoring of the rope and its grounding for safety reasons require that the carrying rope be partially stripped. A conventional solution is to arrange a cable and its supporting rope in parallel and to have at suitable spacing of the yokes or ligatures to fix the rope on the cable.

 The transport of fluids in suspended tubes is very similar to the transport of electrical energy or information in suspended cables. In addition to the fact that the fluid transport tubes can be assigned a path parallel to the path of electrical conductors or optical fibers, in which case the association in a single bundle that is indicated, the suspension of a fluid conductive tube at the Using a grounded carrier cable may in itself be of interest, especially if the fluid is combustible and if the path of the tube includes areas where intense electric fields may prevail.

 The expression bundle does not of course exclude that the cable only comprises an electrical conductor, or an optical fiber or a fluid conducting tube.

Of course it would be preferable if the cable was made with the cable ties from fabrication.cationO
The invention also proposes a self-supporting cable comprising, in addition to a sheath enclosing a bundle of conductors.
t / or optical fibers and / or conductive tubes of f1uid., a supporting wire parallel to the bundle and therefore stripped, characterized in that said sheath enclosing the bundle has d space projections from ex hole ion with the sheath , in the form of screeds around the rope.

 It will easily be understood that the projections which form yokes to hold the carrying rope are carried out during the sheathing operation of the bundle of conductors, operation carried out by extrusion of a plastic material, in a pro Cts.us by continuous essence. It follows that the structure of the above finished cable can only be obtained by implementing a specialized extrusion die.

 The invention therefore also proposes an extrusion die, if not of the kind, comprising an injection chamber supplied with heated thermoplastic material, with an anterior channel for the passage of conductors to be sheathed, and a posterior extrusion nozzle from which a sheathed cable exits. , intended to sheath a self-supporting cable comprising in parallel a bundle of insulated conductors and / or optical fibers and / or tubes conducting fluids, and a partially stripped carrier cable, by extrusion of a tubular sheath around the bundles with spaced projections forming yokes for the carrying line, a line characterized in that it comprises two half-lines with parallel axes, the first affects the bundle and the second the line, equipped with circular end pieces joined by a slot extended along the plane of the axes of the half-lines, and in that the second half-die comprises a valve with a tubular rod forming an anterior channel and movable axially in the injection chamber between a position we posterior where it closes the end piece, and an anterior position where it releases this end piece.

 It will then be understood that, when the valve is in the posterior position, only the end piece of the first half-die delivers the thermoplastic material to form the sheath around the bundle of conductors. On the other hand, when the valve is in the anterior position, the two end pieces deliver thermoplastic material, one covering the bundle, the other the rope, the two extruded tubular forms being connected by an extruded blade by the slot which connects the : emw tips. The periodic operation of the valve plug $ in synchronism with the drawing of the extruded cable ensures the formation, at regular intervals, of the projections in the form of yokes around the rope.

 Preferably, the valve comprises a crown head with a diameter greater than that of the corresponding end piece, and the chamber of the second half-die comprises a posterior supply, and a discharge channel starting from the anterior region. Thus the valve, in the posterior position, rests on the anterior edge of the end piece, the peripheral edge of the head coming to limit the extension of the blade extruded through the slot between the end pieces. The passage into the anterior position of the valve is facilitated by the presence of the discharge channel, through which the thermoplastic material situated on the side of the anterior face of the head can be discharged.

Furthermore, the injection of thermoplastic material from the injection channel to the end piece takes place behind the valve in the anterior position.
The characteristics and advantages of the invention will become apparent from the description which follows by way of example, with reference to the accompanying drawings in which
FIG. 1A shows in perspective a section of self-supporting cable according to the invention
Figure 1B shows the same cable in cross section
2 shows an extrusion die for the cable of Figures 1, in the position where the carrying rope remains bare
Figure 3 partially shows the die of Figure 2, but in the position where the carrying rope is sheathed.

 According to the embodiment chosen and shown in FIGS. 1A and 1B, the self-supporting cable comprises, stretched parallel, a bundle 1 of insulated conductors stranded together, and a carrying cord 2. An extruded tubular sheath 3 surrounds the bundle 1 and has projections 11 extrusion channels, forming yokes for the carrying line 3, -zr by interaralles 5 where the carrying line 2 ap tus t to nr It will be noted that the projections 4 forming tubular yokes' root in the sheath 3 by blades 4a of extruded thermoplastic material.

The bundle of conductors 1 is obviously arbitrary, having regard to the number of conductors required for a particular application, and to their necessary cross section. The carrying rope 2 is formed of strands stranded; the number of strands, their cross section and the material of which these strands are made will be chosen by a person skilled in the art according to the forces which the cable has to bear, the accessory functions which the rope has to fulfill. It is clear that the constitutions of the bundle 1 and of the rope 2 are incidental from the aspect of the problem to be solved, or more exactly represent data of the problem which is the extrusion of the sheath 3 with projections 4 forming spaced yokes. In this aspect the optical fibers are strictly equivalent to electrical conductors. The same is true of conductive tubes of fluids, gases or liquids, except to take into account for the latter the weight of the liquid contained for the determination of the constitution of the rope carrier 2. In view of these equivalences between electrical conductors, optical fibers and conductive tubes in the arrangement of bundle 1, and the accessory nature of the constitution of this bundle with respect to the structure of the cable, it seemed unnecessary to give particular representations of beam sections 1 according to whether they incorporate electrical conductors, optical fibers and fluid-conducting tubes
In addition1 although the expression bundle evokes by itself a multiplicity of electrical, optical, or fluid conductors, it is manifest that here this expression cannot exclude that the bundle consists of a single electrical conductor, a single optical fiber or a single fluid conducting tub, having regard to the accessory nature of the composition of the bundle for the invention.

 The extrusion of the sheath 3, 4 is carried out using a die as shown in Figures 2 and 3, which will be mounted on the nose of a conventional extruder, not shown, capable of supplying the injection channel 12 in thermoplastic material heated so as to be foremost wisqueuse.

The die consists of a body 10, generally in the form of a cup, and a grid punch 11, which penetrates into the body 10 and in the form of a shutter. Conventionally, in the punch 11, a channel lla is practiced, which marries with a reduced clearance the section of the beam 1. In the body 10 of the die, in coaxial alignment with the channel lla, a tip 10a has been machined, of which the section determines the general section of the beam 1 with its sheath 3. The beam will be drawn from right to left according to the representation of FIGS. 2 and 3, according to the direction of the arrow 200 With respect to the direction of drawing of the beam 1, the channel lla will be said anterior channel, and the tip lOa posterior tip. The space between the posterior face of the punch il and the anterior face of the body 10, around the bundle 1, forms injection chamber 13 e All the part of the die adapted to the extrusion of the sheath 3 constitutes a first half-die, conventional0
However, for the execution of the projections forming yokes 4, a second half-die is used, with an axis parallel to the first, which comes through the aborting line 2, which will be pulled in the direction of arrow 20 at the same speed as the beam 1. This half-die comprises a rear end piece lOb machined in the body 10, joined to the end piece lOa by a slot 10th extended in the plane of the axes of half-threads to be complementary to the blades 4a (FIG. 1B in particular ).

 Furthermore, in the punch ll, a cylindrical passage 11b has been machined, coaxial with the end piece lob, which receives the rod 15a of a valve 15; the latter is axially pierced with an anterior channel 15b where the supporting line 2 passes with reduced clearance 2. The head of the valve 5, at the rear end flares out in a crown 15e, adjusted in an injection chamber 14 mena- gée in the rear face of the punch 11. Beyond the crown 15c, the valve 15 is extended by a ring 15d capable of engaging in the nozzle 10b of the second half die when the valve is in the posterior position as shown in Figure 2 .

Chamber 14 is connected in its rear part
"ion feed channel 12 between body 10 and punch llo A discharge caral 15 leaves from the front face of the chamber 14 towards the outside.

 The valve 15, operated by means of its rod 15a which projects from the front face of the punch 11, back and forth according to the double arrow 21, can pass from the rear position shown in FIG. 2, where it closes the end piece 10b, in an anterior position shown in FIG. 3, where the end piece 10b is released. It will be noted that the crown head 15s, of diameter greater than that of the end piece lOb, closes over almost its entire length the slot lOc (FIG. 2).

 When the valve 15 is in the posterior position (FIG. 2), the second half-die assigned to the carrying rope 2 is unused; when the valve is in the anterior position (FIG. 3), the second half-die is put into action, the extrusion starting when the ring 15d is extracted from the lob endpiece. As the flow rate of an extruder, without particular precautions, is substantially volumetric, the flow rate of material necessary for the formation of the projections 4 during the operation in the anterior position of FIG. 3, can be evacuated, in the posterior position of Figure 2, through the discharge channel 16, the supply channel 12 opening into the chamber 14 from the rear face thereof to beyond the space occupied by the head 15c in the rear position of the valve . Furthermore, the communication between the supply channel 12 and the load channel 16 is interrupted at the moment when the movement of the valve 15 er its anterior position releases the end piece 10b, so that the start of extrusion of the projections 4 is indeed form.

 It goes without saying that the valve stem is coupled to a laterally offset cylinder to degas the passage of the rope 2, and that this jack is driven back and forth by valves synchronized on the sheathed cable pulling mechanism, so that the yokes 4 are evenly spaced along the supporting rope 2.

 Of course, the invention is not limited to the examples described, but embraces all the variant embodiments.

Claims (3)

 1. self-supporting table comprising, in addition to a sheath (3) enclosing 11n bundle (1) of insulated conductors and / or optical fibers and / or tubes conducting fluids, a carrying rope (2) parallel to the bundle and partially stripped, characterized in that said sheath (3) enclosing the bundle (1) comprises spaced projections (4) coming from extrusion with the sheath (3), in the form of yokes around the rope (2).  2. Extrusion die of the kind comprising an injection chamber supplied with heated thermoplastic material, with an anterior channel for the passage of conductors to be sheathed, and a posterior extrusion nozzle from which a sheathed cable exits, intended to sheath a self-supporting cable comprising in parallel a bundle (1) of insulated conductors and / or optical fibers and / or tubes conducting fluids, and a partially stripped carrying cable (2), by extrusion of a tubular sheath (3) around the bundles with spaced projections (4) forming yokes for the carrying line (2), fife characterized in that it comprises two half-dies with parallel axes, the first assigned to the bundle (1) and the second to the rope (2), equipped with circular end pieces (10a, 10b) joined by a slot 10c) extended along the plane of the axes of the half-dies, and in that the second half-die comprises a valve (15) with tubular rod (15a) forming a channel anterior (15b) and axially movable in the injection (14) between a posterior position where it closes the end piece (10b), and an anterior position where it releases this end piece.  3. Die according to claim 2, characterized in that said valve comprises a head (15c) in a crown, with a diameter greater than that of the corresponding nozzle (lob), movable in the corresponding injection chamber (14), that -this comprising a posterior supply (12) and a discharge channel (16) starting from the anterior region of the cylinder.  i. Die according to claim 2 or claim 3, characterized in that it comprises a body (10) with a rear face where the nozzles and the window are formed (10a, 10b, 10c), and a grid punch ( 11) where the anterior channel (lla) of the first half-die are led, and a sliding passage (llb) for the valve stem (15a) o