PROTECTIVE NET COMPRISING HIGHLY RESILIENT LOOPS

Abstract

A protective net is formed of individual loops (12, 12, 12) of plastics material threaded into each other. The plastics material can have a modulus of elasticity of between approximately 5000 and approximately 20000 MPa. Each loop (12, 12, 12) of the protective net (10) can be formed by a thread (11) of plastics material wrapped repeatedly over itself. The protective net (10) can be used in an aquaculture installation for the purpose of anti-breach protection for a cage for breeding aquatic organisms.

Claims

1-13. (canceled)

14. Protective net formed of individual loops of plastics material threaded into each other, wherein each loop is formed by a thread of plastics material wrapped repeatedly over itself, wherein the ends of the thread of each loop are secured by welding.

15. Protective net according to claim 14, wherein the ends of the thread of each loop are secured by heat welding.

16. Protective net according to claim 14, wherein the plastics material has a modulus of elasticity of between approximately 5000 and approximately 20000 MPa.

17. Protective net according to claim 14, wherein the thread of plastics material of each loop is wrapped over itself between five and twenty times.

18. Protective net according to claim 14, wherein the thread has a diameter of between approximately 1.5 mm and approximately 3.0 mm.

19. Protective net according to claim 14, wherein each loop has a diameter of between approximately 100 mm and 500 mm, and preferably between 300 mm and 450 mm.

20. Protective net according to claim 14, wherein the inner loops of the net are interwoven with at least another three adjacent loops.

21. Protective net according to claim 20, wherein the inner loops of the net are interwoven with three or four adjacent loops.

22. Protective net according to claim 14, comprising homogeneous groups of loops having the same characteristics as each other, each homogeneous group of loops having different characteristics from the loops of another homogeneous group of loops, in terms of material, strength and/or diameter.

23. Aquaculture installation, comprising a cage for breeding aquatic organisms, further comprising a protective net according to claim 14 arranged around at least part of the cage for the purpose of anti-breach protection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further features and advantages can be found in the detailed description of a preferred embodiment, with reference to the attached drawings, given by way of non-restrictive example, in which:

[0018] FIG. 1 is a view of a portion of a protective net incorporating features of the present invention;

[0019] FIG. 2 is an enlarged view of an individual loop of the protective net in FIG. 1;

[0020] FIG. 3 is an enlarged view of a detail of the loop in FIG. 2; and

[0021] FIG. 4 is a schematic view of an aquaculture installation protected by the protective net in FIG. 1.

DETAILED DESCRIPTION

[0022] With reference now to FIG. 1, a protective net 10 is formed of individual loops 12 that can be threaded into each other. In the example in FIG. 1, each inner loop of the net 12 can be threaded into four adjacent loops 12. It is possible to produce a protective net 10 in which each inner loop is threaded through a different number of adjacent loops, for example three adjacent loops, so as to produce a net with a different geometry from that illustrated in FIG. 1. The edge loops 12 and the corner loops 12 of the protective net 10 can be threaded into a smaller number of other loops than the inner loops 12. One or more peripheral ropes or a bar (not illustrated) can be threaded into the edge loops 12 and into the corner loops 12.

[0023] Each loop 12 can be formed of a thread 14 of plastics material. The thread 14 of plastics material can be wrapped repeatedly over itself so as to form a certain number of turns, bends or twists. In some applications, the thread 14 of each loop 12, 12 12 can be wrapped over itself between five and twenty times. The number of thread turns for each loop can also be smaller or greater, depending on the characteristics of the thread 14 and therefore the desired strength to be imparted to each loop 12, 12, 12. The number of thread turns 14 can also be different for some loops or for some groups of loops.

[0024] The thread 14 can be a thread or monofilament of polyethylene terephthalate (PET), or some other plastics material. The thread 14 can be made of a plastics material having a modulus of elasticity of between approximately 5000 and approximately 20000 MPa. In some applications the thread 14 can have a minimum tensile strength of 230 MPa. The diameter of the thread 14 can be selected on the basis of the strength characteristics to be imparted to the protective net 10. In some applications, the thread 14 of plastics material can have a diameter of between approximately 1.5 mm and approximately 3.0 mm. In one non-restrictive example the thread 14 can have a nominal diameter of 3 mm.

[0025] The two ends 16 of the thread 14 of each loop 12, 12, 12 can be secured by clamps 18 or by fastening members having a similar function. In particular, the ends 16 of the thread 14 can be placed side by side over a sufficiently long length x for the application of at least two clamps 18, which can preferably be spaced apart from each other. The ends 16 of the thread 14 can also be fastened by other systems, including welding, for example heat welding.

[0026] The loops 12, 12, 12 can be generally circular in shape. The diameter of the loops 12, 12, 12 can be selected according to the usage needs of the protective net 10. Simply by way of example, in the case of anti-breach protective nets used to protect aquaculture installations, the loops 12, 12, 12 can have a diameter of between approximately 100 mm and 500 mm, and preferably between 300 mm and 450 mm. The production of a protective net comprising loops of a different diameter from the values shown is not, however, ruled out. In some applications a protective net can be produced having loops or groups of loops that have different dimensions from each other. The dimensions of the loops 12, 12, 12 can be determined so as to take account of the conditions of use of the protective net 10, and in particular the dimensions of the smallest body that might create an impact on the protective net and from which protection is to be provided.

[0027] To produce the protective net 10, loops 12, 12, 12 are formed by wrapping a plastics thread 14 repeatedly over itself a given number of times in order to form a loop of a given diameter. At each turn over itself, the plastics thread 14 can be threaded into a certain number, e.g. three or four, of adjacent loops 12, 12 or 12 already formed.

[0028] After the thread 14 of plastics material has been wrapped over itself by the given number of turns, its two ends 16 are fastened. The two ends 16 can, for example, be placed side by side and aligned relative to each other. The two ends 16 can be fastened to each other and/or to one or more of the turns of the thread 14 that form the loop 12, 12, 12. The two ends 16 can be fastened by means of one or more clamps 18 or other equivalent members. In addition or alternatively, the ends 16 of the thread 14 can be fastened by other systems, including welding, for example heat welding.

[0029] Preferably, the protective net can be produced and supplied in the form of panels of net, of predetermined dimensions, comprising a pre-set number of loops 12 both lengthways and widthways. The edge loops 12 and the corner loops 12 can be connected together by one or more peripheral ropes or bars (not illustrated). The panels of protective net 10 produced in this way can be used individually or can be assembled to produce protective structures of various kinds.

[0030] FIG. 4 schematically illustrates a non-restrictive example of the use of a protective net 10 in an aquaculture installation. The aquaculture installation comprises a cage 20 of a generally known type, for example produced having a close-mesh net made of plastics, nylon or the like, which can be used for breeding aquatic organisms such as fish, molluscs, crustaceans, etc. A protective net 10, having highly resilient loops, of the type described above is fastened a predetermined distance away from the cage 20. The protective net 10 is held in position by systems known in the aquaculture sector, for example by anchors (not illustrated). The protective net 10 can extend so as to cover the whole cage 20 or only the part of the cage 20 that is to be protected, for example, from possible attacks by predators, with an anti-breach function. In the case of impact on the protective net 10 by a predator, the protective net 10 is deformed locally, so as to absorb the energy of impact, warding off the predator. Once the impact has ended, the high resilience of the protective net 10 allows it to return to its non-deformed condition, sufficiently far away from the cage 20 for anti-breach protection. The protective net 10 maintains its characteristics over time owing to its high resilience and to the fact that it is made of a plastics material that is not subject to oxidation.

[0031] Another example of using the protective net 10 described above is for protection against the risk of avalanches and rockfalls. The protective net 10 is secured to the ground in a manner known in the sector, for example by anchors in the ground. Alternatively, the protective net 10 can be held in an erect position by stakes fixed in the ground. In uses of this type, the protective net 10 can easily be transported and installed, even in inaccessible locations, because it is lighter than known protective nets made of steel.

[0032] Of course, without prejudice to the principle of the invention, the embodiments and the implementation details can vary greatly from that which is described and illustrated, while remaining within the scope of the present invention.