FR2642446A1 - METHOD FOR CONNECTING PULTRUDED JONCS TO ATTACHES FOR REALIZING CARRIERS OF CABLES - Google Patents

Abstract

According to the process, there is placed on the rod 3, for example made of carbon fibers, a fabric or braid 2 of mineral or synthetic material, for example of glass fibers, previously impregnated with thermosetting adhesive resin, over a well-determined length of the rod , then the assembly is inserted, under tension, into an attachment body 1 and heated to 60 degree (s) C-120 degree (s) C to harden the assembly. Application, in particular, to the production of supporting and / or reinforcing cables.

Description

The present invention relates to the field of cables and carrier elements

  of cables and more particularly relates to a method

  fastening or assembling extruded rods on end fasteners

tee or mechanical joint.

  It is first of all pointed out that pultrusion, a technique of extrusion in a die with simultaneous drawing of the material, makes it possible to obtain composite rods or cables made of different materials such as, for example, based on carbon fibers or fibers. synthetic

like aramid or whatever.

  The use of high mechanical strength and high modulus synthetic textile fibers, which replace steel in some applications, is becoming more common in the oceanographic, maritime, submarine, air and land domains.

  supporting elements of electromechanical cables and cables

  optical beams or else: cable-stayed guy wires of transmitting and receiving antennas, rigging elements for racing boats, pleasure boats (multihulls and monohulls). It can thus be matched with a considerable increase in power of the machine a decrease in weight

  important mainly at the top of the mast.

  Currently, in the nautismeces poring elements are

  either synthetic assembled and sheathed fibers or stainless steel

  monotoron dart or monofil or steel wire current.

  These cables or shrouds, because of their weight, their

  and their master-couple reduce the performance of

  these sought on the entire guying carried out. In the version

  single-wire stainless steel, no synthetic fiber cable or rope

  is not efficient enough to ensure replacement, because for a

  identical lengthening, the diameter is clearly greater than

  the penetration into the air by increasing windage and

  aerodynamic drag: main criterion of cable selection.

  Until now, the use of pultruded rushes

  carbon or synthetic fibers, of which we know the excellent per-

  has not been considered because, in particular, of the difficulty or immssibility of firmly linking these rods to end attaching elements or joining which are of small footprint and give rise to sets of great resistance to breaking. Attempts

of collage, by--. .

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  resins, polymerizable compositions or the like, ex-

  of the rods before and during the introduction into an element or body of attachment gave mediocre and disappointing results both

  adhesion of the glue than to the mechanical results

  obtained, particularly with regard to tensile strength.

  The invention provides a solution to this technical problem.

  and that its purpose is to achieve assemblies rods - fastening bodies of great mechanical performance and having the qualities of lightness, low alvonqement and aerodynamics that are usually sought

in the above applications.

  To achieve this goal, the invention proposes a method

  fixing pultruded rods, based on natural or synthetic fibers

  on end-attaching or joining bodies, according to which: a / is provided on the rod a fabric or braid, of mineral or synthetic material, pre-impregnated with a polymerizable adhesive composition , this in proximity and over a length at least equal to that of the fastening body; b / The assembly is inserted, under tension, into the attachment body; then: c / the braided part is heated and the body of attachment at temperature

between about 60 and 120.

  The pultrude rush, considered here as known per se,

  may be selected from existing materials such as synthetic fibers

  theories with high physical and mechanical performances, such as

  the Aramid fibers. According to a preferred embodiment, although not

  limiting, we will limit ourselves in the description which follows to the case of the rushes

  of carbon fibers obtained by pultrusion of series of wicks

  high-strength carbon laments in a synthetic resin matrix

impregnating tea.

  According to the invention, in the zone of proximity of the fastening body which will be used to fix the ring securely, it has

  on the latter a fabric or braid of natural or synthetic material

  tick. In practice, it has proved convenient to implement,

  in the case of the carbon rod, a fiberglass braid adapted to be threaded, like a sock, around the rod or cable to

  from one end of the latter. This braid is previously im-

  resinous resin or polymerizable synthetic composition suitable for

  constitute a means of gluing and selected from the known products,

  for example, compositions based on epoxy resins and amine.

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  According to a preferred embodiment of the invention, the length

  braid, arranged on the rim and close to the body of attachment,

  is a ,, less than three times the length of this home body.

  Other features of the invention will appear

  in the description which follows, relating to a non

  limiting and illustrated by the attached drawings which represent a schematic

tically: -

  - Figure 1: a sectional view of the assembly of the end fastener mounted according to the method of the invention; - Figure 2: a more detailed view, in half section, the end attachment body; - Figure 3: a sectional view of a complete assembly of a rod equipped with

  both ends of a fastener.

  As can be seen in Figures 1 and 3, a

  seems to be realized according to the invention essentially comprises: the pultruded ring 3, the braid 2,2 'over a determined length and the means

  end attachment or attachment body 1,1 '.

  According to a particularly advantageous example of

  the rod used, with a resistance of 4600 daN, consists of

  a set of 32 strands of 12000 high-resistant carbon filaments

  impregnated with a thermosetting resin composed of 100 parts

  parts (weight) of epoxy resin for 27.5 parts (weight) of amine as

  hardener. After setting to reed length, according to the pro application

  discarded, then abrasive passage thereof, it cleans with solvent (eg acetone) the part that will be intended for wrapping by the braid. The latter, for example glass fibers, is pre-impregnated with polymerizable resin - as for example that mentioned above based on epoxy / amine - then it is cut to a length at least equal to that of the fastener body. In practice this length of braid is important because it determines the final strength of the cable formed. Most often, it is of the order of three to four times the length of the body of attachment. So, in the aforementioned example of the

  carbon fiber, knowing that the thermosetting resin has a resistance

  With a tensile-shear ratio of 2.4 daN / mm 2, it is determined that 94 mm of bonding length represents a strength of 4610 daN which is then compatible with the carbon rod of 4600 daN. This length

  94 mm will then be that of the body or bodies.

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  The implementation of a braid, for example here in

  glass, is especially advantageous because of the inclination of the fibers relative to the axis of the rod. These fibers are arranged in a helix on the periphery of the ring, which highly favors self-tightening when pulling on the fastener body and makes it possible to increase the resistance.

  this of the assembly made according to the invention.

  According to an alternative embodiment, the braid may be covered, before polymerization of the impregnating resin, with a sheath of heat-shrinkable plastic material which, thanks to the

  shrinkage phenomenon, eliminates the surplus of the agent of im-

  prégnation as well as the possible imperfections of the collage.

  The braid thus cut and impregnated is then

  spun on the rod and then introduced the assembly under tension in the fastener body to the end of the braid. The fastening body is then brought flush with the end of the pultruded ring and then the length of braid which projects beyond the fastening body is cut. The assembly is finally maintained at a temperature generally of between 60 and 120 ° C.

  to ensure the polymerization and hardening of the resin of im-

prégnation and collage.

  The fastening body 1, which may be metal (like

  titanium) of metal alloy or synthetic polymer (such as

  mide), is advantageously in the form of a tube whose wall

  may be smooth or provided, on all or part of the length

  of circular grooves. According to one variant, these grooves may also be helical. According to the preferred embodiment illustrated in the detailed figure N 2, the fastener body is provided at the flat part 4 for clamping, a slight shoulder 5prolonged by a threaded element 6 which allows any connection with a device

  anchor or an end cap for the recovery of the effort.

  Thanks to the method of the invention, combinations of

  cables for high strength and extremely reliable carrying cables.

  For example, for comparison, when performing a conventional anchoring / bonding on a pultruded rod of carbon fiber, diameter 4 mm,

  a breaking load of the order of 1500 daN is obtained; while, se-

  In accordance with the teachings of the invention, loads of at least 2400 daN are achieved and the performance of the

system to fatigue.

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  The applications of the process are numerous and one can cite, for example: the realization of carrying cables and of

  towing, mast rigging for boats, structural reinforcement

  building, such as for surgical operating tables

  wedges ... etc. It is also possible to use the fastening system according to the invention

  on the carriers of electronic cables or fiber optic cables

  the electrical or optical part which can be connected in a

  waterproof to the body of attachment described above.

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Claims (6)

-REVENDICATIONS- -R E V E N D I C A T I 0 N S-   1. A method for fixing pultruded rods, based on natural or synthetic fibers, on end attachment bodies or junction, characterized in that a / we have on the rod a fabric or braid, in mineral or synthetic material, previously impregnated with a polymerizable adhesive composition, this in proximity and over a length at least equal to that of the fastener body; b / the assembly is inserted, under tension, into the attachment body; then: c / the braided part is heated and the body of attachment at temperature between about 60 and 120.   2. Method according to claim 1, characterized in that the pultruded ring is made of carbon fibers while the braid (or fabric) comprises either glass fibers or carbon fibers   or again synthetic polymers.   3. Method according to any one of claims i or 2,   characterized in that the fastening body is constituted by an element   hollow metal, such as titanium, metal alloy or synthetic polymer   than. 4. Method according to claim 3, characterized in that the hollow element is a tube dornt the inner wall is either   on all or part of its length of circumferential grooves helical or helical.   5. Method according to any one of claims 1 to 6,   characterized in that said braid is covered before insertion   in the fastening body and the polymerizate, a plastic sheath heat-shrinkable tick.   6. Set of pultruded rod connection (3) - dressing braid (2,2 ') fastening body (1,1') ends or junction, made   according to any one of claims 1 to 5 and used as cables   carriers whose fasteners can be connected to electromagnetic cables. optical or fiber optics.