FR2655814A1 - ELECTRICAL FENCES WITH METALLIC CONDUCTIVE ELEMENTS BASED ON A COPPER / CADMIUM BINARY ALLOY. - Google Patents

Abstract

Electric fence comprising electrically conductive elements based on a metal alloy, characterized in that said metal alloy is a binary copper / cadmium alloy coated at its periphery with a layer of nickel. Application: any application of electric fences, in particular within the framework of the rationalization of pastures.

Description

ELECTRICAL CLOPS WITH METALLIC CONDUCTIVE ELEMENTS

  BASE OF A COPPER / CADMIUM BINARY ALLOY.

  The invention relates to electric fences and more particularly to metallic conductive elements

  integrated in these electric fences.

  Electric fences are now widely used, especially in the context of

  pastures, in order to rationalize grasslands as much as possible

  Electric fences are also used for the protection of plantations and crops against wild animals. In fact, a protected perimeter can be defined precisely according to the choice of users.

  taking into account the specificities of each

  However, the delimitation of certain parcels requires large distances of electrification.

  account for such distances, the amount of electricity

  In fact, the electrical impulses delivered must be sufficient at every point of the fence, even the farthest from the fence.

  the energizer, in order to keep the animals

  Likewise, the effects inherent in the ambient humidity must sometimes be taken into account.

  Finally, sometimes plant elements

  fences cause grounding between

  of the drivers, effectively canceling the effect

  preventive researched by the use of these fences.

  In known manner, an electric fence first comprises an energizer, intended to deliver an electric current in the form of very short pulses and low amperage, but relatively high voltage, up to several thousand volts and the fence properly so-called, constituted of either

  simple conductive wire, either of one or more wires

  integrated in a support made of syn-

  non-conductive thetics, for example in the form of strands, braids or ribbons, or in the form of a mesh consisting of several metallic conductors knotted or welded together, more specifically intended for fleets with sheep, goats, pigs, etc., or even more

  simply a single conductive cable.

  Metal conductors without synthetic support or similar, were quickly abandoned because of their low visibility, which can lead to damage in protected areas as well as in penned animals. In fact, it is common practice to

  day to use fences incorporating a support, including

  synthetic material of bright color, or even fluorescent.

  Fundamental difficulties are manifested by the use of such electric fences First of all, it is common to observe breaks in the metal elements, due to frequent changes in grassland configuration, thus causing folding or rewinding of son , and in fact causing local mechanical stresses in one direction and then in the other, generally resulting in the break

  of the metallic conductor These cuts are not generally

  not detectable when these metallic elements are integrated in a synthetic

  lead to local alterations, or even an annul-

  total conduction of electrical conduction in certain

  points of the fence and therefore, its effectiveness.

  Then, when using such fences for large perimeters, the resistivity of the conductive materials used may lead to insufficient voltage pulses to deter the parked animals

  to lean against these fences, or even to cross them.

  To overcome the first difficulty mentioned above

  above, it has been proposed to use conductive metal wires made of stainless steel, given the good mechanical properties of this material, and in particular its elongation capacity. Thus, these metal wires can be assembled with synthetic wires by

  weaving, braiding, twisting, knitting, etc.,

  In contrast, stainless steel has a relatively high electrical resistivity, resulting in a linear resistance typically of a few kilo-ohms per kilometer (k Q / km) for a diameter of the order of 0, 20 millimeters, to the detriment of good conductivity

  In this way, the use of such conductors

  metal is not feasible for large and medium-sized fleets, except to use

  several energizers, which considerably increases

  the cost of such an electric fence.

  To overcome the difficulty inherent in

  electrical supply, it was then proposed to use wires

  metallic conductors made of copper or aluminum

  Although the problem of distance with respect to electrical conduction is solved, on the other hand, these two metals are known for their weak mechanical properties and the corrosion to which they are subjected, especially when they are under tension. they break rather quickly, leading to conduction stops where the fence is inefficient as well

incorporated.

  It was then proposed, to overcome simultaneously these two disadvantages, namely on the one hand the mechanical strength and on the other hand the electrical conductivity, for example in the document EP-A-0 256 841, to associate in the same fence electric, two types of drivers,

  respectively a driver with good mechanical properties

  and a conductor with good electrical conductivity.

  In this way, when the driver of good electrical properties breaks locally, and taking into account their insertion in a textile support in braided form, the relay of the electrical conduction is ensured by the son of good mechanical properties, which allows to ensure the continuity of the electricity supply to

  another metallic element that is a good conductor of electricity

  quoted However, it should be noted that this result is only possible with a braided support, otherwise

  there is no contact between the different metallic conductors

  and the relay can no longer be ensured. In addition, the conductor with lower electrical conductivity affects overall electrical conduction, tending to the same results as an electric fence incorporating a

  metal conductor type stainless steel.

  The invention overcomes these various disadvantages.

  It proposes an electric fence in which lead wires of a single type of metal alloy are inserted, said metal alloy being a binary copper / cadmium alloy coated on the periphery of a layer.

of nickel.

  Indeed, it has been shown, that the addition of a small proportion of cadmium to a mass of copper, the alloy thus produced being then stretched in the form of wire, allows to combine both a good conduction of electricity, very close to that of copper, and good mechanical strength far superior to that of copper. Moreover, the nickel-based coating makes it possible to significantly increase the resistance to

  corrosion and thus the longevity of the fences thus

  In addition, the elongation rate obtained with this alloy reduces the risk of rupture during repeated bending. Advantageously, in practice, the concentration in

  cadmium in the copper / cadmium binary alloy, is

  between 0.5 and 2% by weight, and advantageously

  In fact, if this concentration is less than 0.5%, the properties resulting from

  the addition of cadmium are practically not

  On the other hand, the addition of a quantity of

  cadmium greater than 2% by weight, does not lead to any improvement

  significantly and, on the other hand, has a significant additional cost in view of the price of the raw material,

know cadmium.

  The metallic conductive elements are inserted in a plaited, stranded, or in the form of braided or knitted or woven ribbon

  synthetic fibers non-conducting electricity.

  Electric fences may also be in the form of a net whose meshes are made

  from the thread described above,

  mesh sections being obtained, in known manner, by knotting or welding It goes without saying that the invention also relates to the son without support

synthetic, used alone.

  The way in which the invention can be realized and the benefits that flow from it will emerge better from

  the following example, which is given as an indication

  tif and not limiting in support of the appended figures.

  Figure 1 is a schematic view of a woven ribbon constituting an electric fence according to the invention. Figure 2 is a wire of a braided electric fence.

  FIG. 3 is a schematic view of an electrical wire

stranded box.

  In each of the figures represented, of structure

  otherwise known and not claimed, each of the

  metal elements (1) consists of a copper / cadmium binary alloy, in which the concentration by weight of cadmium is 1% This alloy is produced by casting

  in the form of an ingot, said ingots then being laminated

  born, then drawn to the desired diameter The wire obtained then undergoes a duration annealing operation

  determined, in order to give it characteristics of

  long and desired solidity.

  The yarn thus produced then undergoes periodic nickel plating.

  The nickel layer thus deposited reaches a thickness of the order of 2.8 μm. The resulting conductive elements (1) have a typical diameter of 0.2 mm and exhibit mechanical strength at room temperature. of 34 da N / mm 2 These metal wires have a typical elongation of 23%, that is to say the same as that of stainless steel. The linear electrical resistance has also been measured. It is equal for diameter wires. on the order of 0.20 mm to 0.615 Q / m,

  some four times less than that of stainless steel

corn.

  Although the example described relates to a wire of

  being close to 0.20 millimeters, it goes without saying that the invention

  intended to cover the yarns made in accordance with

  concentration of the various elements described, without

dimensions.

  Depending on the structure of the fence in which they are integrated, namely respectively a woven ribbon (Figure 1), a braid (Figure 2) or a strand (Figure 3), the metallic wire (1) is surrounded by a plus or smaller number of synthetic threads (2,3) and in this way, the mechanical strength of the assembly can be increased.

  intended to be particularly visible to animals

  evils that they are supposed to park or on the contrary make flee. Tests have been carried out to test the corrosion resistance of the conductive wires

  These tests are carried out according to the technical

  what is known as the "salt spray" described below

  known manner, a tinned copper exposed during a period

  a neighbor of one year to bad weather in a temperate country, of determined hygrometry, for example France, presents the same aspect as a wire of the same nature and with the same dimensional characteristics subjected to 148 hours

  salt spray and under operational conditions.

  These are as follows: temperature: 350 C sodium chloride concentration NaCl: 5% test duration: 148 hours This salt spray test was carried out for comparison on: A: a copper-plated wire nickel; B: a wire made of nickel-plated copper; C: a wire according to the invention (nickel-plated Cu-Cd); D: a wire made of stainless steel;

  E: a wire made of tinned copper.

  Corrosion ratings are graded according to grades of 0 (no trace of corrosion) to 5 (significant corrosion), and reported in the following table:

  IEPROUVETTE | DURATION OF NOTES QUOTATION

E | AND BL'ESSAI CORROSION

  At 48 h 3 red corrosion 2 to 3 mm / cm B 48 h ORA S. C 48 h ORA S. D 48 h ORA S. E 48 h 4 tarnishing + whitish traces ******* * *** ***** t ******** ***** * * ******************

At 148 hr 4 orange rust -

  very brittle yarn B 148 h ORA S. C 148 h 1 black dots D 148 h ORA S. E 148 h 5 generalized tarnish + whitish traces This result shows the very good stability of the metallic conductor made of nickel-copper / nickel-cadmium binary alloy. indeed, if it presents some slight traces of corrosion after 148 hours, which are otherwise imperceptible to the naked eye

  and only visible under a microscope and this in a

  on the other hand, it presents a much better

  electric power than stainless steel (D), and a

  better strength than tinned copper (B).

  Thus, the use of such conductive materials in electric fences allows, besides obtaining electric fences of sufficient mechanical strength but necessary for this type of application, and good

  electrical conduction at competitive prices, to increase

  prolong the life of batteries and other electri-

  which also represent an important investment

  both when buying such fences.

  Finally, the user of such fences is assured of having at all points an electric current whose impulses are adapted to move the animals away from them. AT,&

Claims (4)

  1 / Electric fence comprising elements con-   conductors of electricity based on a metal alloy, characterized in that said metal alloy is a binary copper / cadmium alloy coated on its periphery a layer of nickel.   2 / electrical fence according to claim 1, characterized in that the concentration of cadmium in the binary copper / cadmium alloy, is between 0.5 and 2% by weight, and preferably about 1% by weight. 3 / electric fence characterized in that it   consists of a single cable made according to the   riau described in claims 1 and 2.   4 / Electric fence according to one of the claims   1 and 2, characterized in that the conductive elements   (1) are inserted in a multi-layer   braided, stranded, or in the form of braided, woven or knitted ribbon, made of synthetic threads (2,3) no conductors of electricity.   Electric fence according to one of the claims   1 and 2, characterized in that it consists of a net whose meshes are made from the thread   conductor (1), the wires (1) of the meshes being solidari-   at the intersections of the stitches by knotting or by welding.