JP2017179689A - Method for manufacturing closed-loop cable by splicing, corresponding cable and usage thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a closed-loop cable having long lifetime, capable of reducing vibrations generated when knots of carrying-hauling cables move over rollers of a transportation installation.SOLUTION: The present invention provides a manufacturing method for a closed-loop cable. The method includes the steps of providing a cable 1 including a core 2 and metal strands 3 helically wound around the core 2, connecting two ends of the cable 1 in splice areas via splice knots formed by ends of each metal strand 3, inserting the metal strand ends inside the cable after locally removing the core and subsequently overmolding each splice area using a polymer. The invention also concerns a method for manufacturing a closed-loop cable where the ends of the strands 3 are dressed by overmolding them using a polymer, prior to inserting them inside the cable. The invention concerns a method for manufacturing a closed-loop cable where prior to the step of overmolding, spacers are inserted between each strand such that an existing play between the metal strands at each splicing area is uniformly distributed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of making a closed-loop cable by means of twisting, and the resulting closed-loop, more particularly, but not limited to, cable transport equipment in which a hauling or haul-pull cable is used. Relates to a closed loop intended to be incorporated into

  In order to make such a closed loop cable, it is necessary to make a splice that functions to connect both ends. Such twisting closes the cable on both sides of the mating region by repositioning half of the strands from each cable end, and thus articulates, and then creates a knot between each pair of aligned strands; Each of the knotted strands then involves insertion at the location of the corresponding twisted region of the core previously removed locally of the cable.

  In the context of the present invention, a twisted region is understood to mean a region comprising a twisted knot and two cable parts immediately adjacent to this knot. Along the region, two knotted strands are inserted into the space of the cable core.

Thus, according to the state of the art, twists inevitably involve locally irregular geometric parts, and in particular:
Constructing the cable, near the knot made between the aligned strands adopted in the pair style,
Near the distribution of the portion of play between the outer strands on one side of the aforementioned knots (along the region, the knotting strands are inserted into the core in place);
Or, various levels of vibration occur at the end of each such insertion area.

  In fact, in the twist region moving on each roller of the equipment, a movement that can reach a width of a few millimeters occurs. Thus, as will be appreciated, depending on the speed of the cable, each roller in the installation is affected by a series of sporadic movements or periodic vibrations (this The frequency can be either moved by tens of hertz or even hundreds of hertz depending on the case.

  Such vibrations are inherent in the pulling or carrying-pull cable twisting according to the state of the art, but destroy the environment (eg the generation of noise near residential areas) and It may be such that it accelerates the wear or fatigue of some components, in particular the cable itself, or the component of the device in which the cable loop is used.

  This situation is particularly seen in cable transportation facilities that are frequently operated at very high utilization rates, either for humans or for materials, and have a useful life of typically several decades.

  Accordingly, the object of the present invention is to provide a highly geometrically twisted twist to significantly reduce or even completely eliminate vibrations occurring in this region and to extend the life of the cable. Providing a twisting method for obtaining a closed loop cable having such a disadvantage is to improve such disadvantages.

  For this purpose, the subject of the present invention is a method of making a closed-loop cable, the cable comprising a core and a metal strand spirally wound around the core, wherein the cable Both ends of the strand are connected to a twisted region where a twisted knot is formed by each end of the strand, and then the core is removed locally before inserting the end into the cable, Then, it is the method of overmolding each twist area | region using a polymer.

The method according to the present invention further comprises the following features employed alone or in combination:
Overmolding is performed partially so that the top of the strand is not coated with polymer;
Evenly distribute the existing play portion between the strands of each twisted area before overmolding;
The play portion is distributed by inserting spacers shaped for this purpose between each strand;
The spacer has an outer surface that holds the polymer in place after overmolding;
The end of the strand that is inserted into a fixed position of the core on one side of the twisted knot is shortened so that there is a gap between the end and the core after the end is inserted into the cable. The voids are filled with a polymer;
Overmolding is performed using a two-component thermosetting polymer Overmolding is performed using a mold having a cylindrical inner volume;
Before inserting into the cable, the ends of the strands are dressed by overmolding with a polymer;
The cable includes a unitary core with a central core and fins uniformly distributed between the portions into which the strands are inserted, and overmolding of the twisted region reconstructs the fins in the twisted region Fulfill function,
Can be incorporated.

  Another subject of the present invention is a method of making a closed loop cable, the cable comprising a core and a metal strand spirally wound around the core, wherein both ends of the cable are connected to each other. , Each strand end is connected to a twisted region where a twisted knot is formed, and then the core is locally removed, then the end is inserted into the cable, and the end of the strand is This is a method of dressing by overmolding with a polymer before inserting into the cable.

  Another object of the present invention is a closed loop cable obtained according to the present invention.

  Another subject of the invention consists of the use of a closed loop cable according to the invention as a pure pulling cable or a transport-pull cable.

  The present invention has been presented by way of example only and will be better understood using the following description and referring to the accompanying drawings.

It is a perspective view of the cable cut | disconnected before twisting. FIG. 3 is a perspective view of a play distribution spacer that can be used in the method according to the present invention. It is a schematic diagram of the cross section of the cable in which the distribution spacer equivalent to FIG. 2 was inserted.

  The method of making a closed loop cable according to the invention can be advantageously used for twisting a pulling cable with a unitary core carrying several outer strands made of steel wire, where The number of such strands is in most cases 6 and is made according to the patent application PCT / FR12 / 000152 in the name of the applicant and is described below by way of example and not limitation with respect to this application document.

  In the context of the present invention, a closed loop refers to an infinite loop obtained by twisting one end of a cable to the other end of the cable, where the ends are mated face to face. The term does not specifically include cables having end loops such as slings.

  Thus, in essence, twisting pre-loads the knots between each pair of aligned strands by replacing half of one strand with the other (and vice versa) in each case where the number of strands is even. After fabrication, the ends of the strands are “paired” at both ends of the cable by inserting them into the cable within the area from which the core has been previously removed. If the number of strands is odd, at one end of the cable that is connected, one replaces a greater number of strands than the other, where the two numbers of strands replaced at each end are half the number of strands in the cable. Corresponds to two consecutive integers containing equal values. Due to the fabrication of the knot between the pair of aligned strands and, to a lesser extent, the insertion of the knotting strand into the interior of the cable, a local increase of more or less various diameters occurs, which is 10% of the nominal cable diameter. Up to this level, and the current state of the art requires that this value not be exceeded.

  The total twisting operation generally requires about 10 workers.

  In detail, the production of a closed-loop cable by twisting starts in a traditional manner with the production of two regions of the cable that need to be joined by a bond at each end. This coupling is generally accompanied by the help of metal wires, each placed in the middle of the estimated length of the twisted region in order to precisely place the region for “pairing” of the two cable ends. Done. One skilled in the art will know how to determine this length, particularly based on the cable diameter. In a lift installation, the total length of the twist is 1200 times the nominal cable diameter. Thus, for a 54 mm diameter cable this is approximately 65 m long.

  Once coupled, the two cable ends are mated to one or more cable windings and then soft jaws (if any) to avoid movement (if any) of the two cable ends during twisting soft jaw) on the mating region; remove the two knots and unwrap every other strand from each cable end and replace it with an aligned strand from the other cable end, Run to the position selected by the splicer for each knot position (for both cable ends), then straight into the core in place along the length intended to be inserted into the end of each strand To.

  Each aligned strand is then knotted into an aligned strand from the other cable end to form as many twisted knots as there are aligned strand pairs. In such a distribution of nodules formed over the entire length, each nodule is generally several meters away from the adjacent nodule, so it is important to follow a pre-selected exact position.

  Then, on one side of each twisted knot, each strand end is inserted into the cable where it is replaced with a core that has been intentionally pre-removed along the corresponding cable portion.

  In order for the outer strands to have good support, the strands inserted in place in the core must generally be coated with a dressing consisting of a bonded adhesive fabric.

  Reference is now made to cable 1 made according to application PCT / FR12 / 000152 and shown in FIG. It will be appreciated that this includes a unitary core 2 with six fins 4 extending between which six strands 3 are inserted. The strand 3 can conventionally be composed of an assembly of wires of various diameters spirally wound around a central wire. This is preferably a metal, more particularly preferably steel. A strand may further be included in the center of the cable core. This strand may conventionally be composed of an assembly of wires of various diameters spirally wound around a central wire. This is preferably a metal, more particularly preferably steel. Finally, the core of the cable may also include fibers that are longitudinally inserted into the core, metallic or otherwise.

  The cable 1 is substantially at the end for the purpose of minimizing vibrations and noise generated by the cable passing over the guide rollers and generally over the take-up members of the equipment in which the cable is used. Has a cylindrical outer surface.

  Due to the use of the core 2 and the fins 4, the center-to-center spacing between adjacent strands 3 is therefore the case for this type of cable in the case of pulling or carrying-pull cables in a conventional configuration according to the state of the art. I know it will be bigger.

  As a result, in an equivalent metal section, the diameter of the normal part of the cable 1 has been found to be slightly larger than that of a conventional configuration of pulling or carrying-pull cables, which causes the loop to be tensioned. When placed underneath, the twist at the finished knot between the paired-type aligned strands is contrary to what is possible when twisting a conventional configuration of pulling or carrying-pull cables. It is possible to obtain a diameter close to or even equal to that of the cable under tension outside the region.

  In order to further improve the geometrical regularity of the twist, one aspect of the present invention is to provide an overmolding step for each twist region where a polymer, such as a two-component thermoset polymer, such as a suitable grade of polyurethane, is used. Consists of adding. Another aspect of the invention, which will be described in more detail, consists of adding an overmolding step around each strand to be inserted opposite the knots created in a paired manner between aligned strands. Each aspect of the present invention may be implemented separately or in combination, and in particular, the overmolding of each inserted strand is advantageously carried out during the transport or transport-pull cable twisting according to the state of the art. Can be used.

  Due to the overmolding of each twist region, the most cylindrical surface possible is thus reconstructed over the entire length of each twist region, thereby improving the geometric regularity of the cable and thus improving its performance. obtain.

  By overmolding the twisted region, as many fins 4 in this region can be reconstructed as possible to obtain a substantially cylindrical surface characteristic of this type of product, so at each point in the twisted region, It can be ensured that the surface geometry of this region is comparable or very close to that of the normal part of the cable.

  In a preferred embodiment, the twisted region is partially overmolded so that the upper part of the strand is not covered by the polymer, thereby avoiding this increase in diameter.

  In a preferred embodiment, in each twisted region where each of the paired alignment strands is inserted into place in the pre-removed core, once the corresponding knot has been made, it is adjacent before proceeding to overmolding of the twisted region. The play portion is evenly distributed between the strands.

  This uniform distribution can be shown, for example, in FIG. 2 showing a distribution spacer or part of the play portion (also in FIG. 3 which can show this insertion between two strands 3). Can be conveniently obtained along each of the aforementioned regions by inserting as many double throat spacers 5 at even intervals as close to each other as necessary. For example, spacers can be inserted every 10 to 25 cm.

The spacer 5 has the following functional parts:
Lower double chamfer for easier insertion between adjacent strands to provide space, and throats on both sides of the central portion, where each of these throats is two adjacent Are intended to be received by one of the strands, thereby providing a space so as to obtain a corresponding spacer sandwich between the two strands described above,
Can be provided.

  In a preferred embodiment, the spacer 5 can further comprise two inclined ends whose side view has a trapezoidal shape, in which case this small dimension is located on the aforementioned double chamfered side. As a result, each spacer constitutes a joint for holding the overmolded portion of the twisted region according to the present invention.

  The spacer is a sufficiently hard and durable material over time, such as a metal or polymer that is not as hard as the steel of the wire that makes up the cable (to increase compressive strength and / or wear resistance, or otherwise Composed of or not including fillers intended to impart lubricating properties.

  Further, at the state of the art, each strand that is inserted is possible in a state where it is in contact with the remaining core portion of the cable length adjacent to the insertion region in the longitudinal direction when inserted into a predetermined position of the previously removed core. In order to enter as accurately as possible, it is cut to the required length before it is fully inserted.

  However, it is very difficult to cut exactly to the desired length with every care to cut the length of the inserted strand precisely, as a result of which the cut is slightly too long May become clogged during deployment, or if the cut is too short, there will be insufficient support of the outer strand over a length that can reach up to several millimeters, resulting in local reduction in cable diameter, or Furthermore, the contact between adjacent outer strands can be more or less intense, which can lead to the early appearance of many broken wires in this region.

  In a preferred embodiment, the inserted strand is optionally cut to a length slightly shorter (eg, a few millimeters) than the space available for insertion of the previously removed core into place.

  Thus, the small volume thus created at the end of the inserted strand is readily available for complete filling upon injection of the polymer for the corresponding twisted region overmolding and is therefore in place in the core. The function is to provide optimum support of the outer strand near the end of the inserted strand.

  In another preferred embodiment, the step of dressing the ends of the strands comprises placing a particular dressing on each side of the knot that is created between the paired alignment strands around each inserted strand, It can be improved even more than the state of the art.

  This particular dressing is obtained by overmolding a qualified material around each strand. For this purpose, a two-component thermosetting polymer, such as a suitable grade of polyurethane (this pre-curing fluidity is easily filled into a mold that is fixed around the entire length of the dressed strand. Can be used in particular.

  In addition, the material used for overmolding should have the hardness and final mechanical strength to support the pressure over time by the strands loaded on the overmolded dressing once the twist is made. Good.

  Whether with a mold for the twisted region or with a mold for dressing overmolding, the mold used can have one or more parts. Thus, they are made, for example, in the form of opposing trays provided with side end flanges intended to firmly connect them so that the molds are formed within a single cylindrical interior volume. Preferably defining a cylindrical interior volume.

  The polymeric material used for such overmolding can be, for example, a two-component thermosetting polymer (such as a suitable grade of polyurethane).

  Alternatively, a hole that allows the injection of the liquid phase polymer may be made in the upper part of the mold.

  In addition, the mold may be equipped with a heating system intended to accelerate the curing and solidification of the two-component thermosetting polymer that can be used for the various types of overmolding described above. The heating system may be an integral part of such a mold, or alternatively may consist of a heating system disposed around the mold itself.

  Molds intended to overmold the strands that are inserted into place in the core preferably center the overmolded strands to ensure that the overmolding is concentric around it. For spikes or studs.

  For molds intended for overmolding in the twist region, ensure the tightness of the overmolding polymer when pouring, but allow the overmolding material to flow slightly out of the cable. A flexible material intended to come into contact with each of the strands (eg, a polymer of suitable hardness) can be provided.

  The closed-loop cable according to the invention is more specifically intended to be incorporated as a pure tension cable, or transported in a facility (such as a gondola lift or ropeway) for transporting people by cable. -A pulling cable.

  Besides such applications, the closed loop cable according to the present invention can be used in many other applications, such as urban traffic systems, and is therefore not limited to the aforementioned uses.

  Although the method according to the invention has been preferentially described using a cable according to the application PCT / FR12 / 000152, it can of course also be applied to the twisting of other pulling or conveying-tensioning cable types and thus formed. Needless to say, this is also adapted to improve the service life of the cable and part of the inevitable geometric irregularities of the twist. Therefore, this is also included in the present invention.

  Finally, the method according to the invention, in all respects, meets the harmonized standard EN 12927-3 (Safety requirements for cableways installation designated to carry persons, Cables. Part 3: Splicing of ul h Note that it is useful for making twists.

Claims (13)

  A closed loop cable manufacturing method, wherein the cable includes a core and a metal strand spirally wound around the core, and both ends of the cable are twisted by ends of the strands. And then locally removing the core and then inserting the ends into the cable, followed by overmolding each twisted region with a polymer. A method characterized by:   The method according to claim 1, wherein the overmolding is partially performed so that the upper part of the strand is not covered with the polymer.   3. A method according to claim 1 or 2, characterized in that the existing play portions between the strands of each twist region are evenly distributed before the overmolding.   4. A method according to claim 3, characterized in that the play portions are distributed by inserting spacers shaped for this purpose between each strand.   5. The method of claim 4, wherein after overmolding, the spacer has an outer surface that holds the polymer in place.   The end of the strand inserted at a fixed position of the core on one side of the twisted knot is shortened so that there is a gap between the end and the core when the end is inserted into the cable, and is later overmolded. The method according to claim 1, wherein the void is filled with a polymer.   The method according to claim 1, wherein the overmolding is performed using a two-component thermosetting polymer.   The method according to claim 1, wherein the overmolding is performed using a mold having a cylindrical inner volume.   9. A method according to any one of the preceding claims, characterized in that the end of the strand is dressed by overmolding with a polymer before being inserted into the cable.   The cable includes a unitary core with a central core and fins uniformly distributed between the portions into which the strands are inserted, and overmolding of the twisted region reconstructs the fins in the twisted region 10. A method according to any one of the preceding claims, characterized in that it performs the function of:   A closed loop cable manufacturing method, wherein the cable includes a core and a metal strand spirally wound around the core, and both ends of the cable are twisted by ends of the strands. The strand is inserted into the cable after the core is locally removed and then the end is inserted into the cable. A method comprising dressing by overmolding with a polymer before.   A closed loop cable obtainable by the method according to claim 1.   Use of a cable according to claim 12 as a pure tension cable or a transport-pull cable.

Images