AU2012283748B2

AU2012283748B2 - Improvements in cable stockings

Info

Publication number: AU2012283748B2
Application number: AU2012283748A
Authority: AU
Inventors: Peter COOCH; Dane HANSEN; Marc Hansen
Original assignee: LB WIRE ROPES Pty Ltd
Current assignee: LB WIRE ROPES Pty Ltd
Priority date: 2011-07-08
Filing date: 2012-07-09
Publication date: 2016-03-24
Anticipated expiration: 2032-07-09
Also published as: AU2012283748A1; WO2013006903A1

Abstract

A cable stocking (10) has a first end (201) and a second end (202) arranged such that when an axial tension is applied to the stocking, it results in elongation and contraction of the stocking. The stocking comprises a weave, braid, or plait of ropes made from non-metallic fibres, most preferably a high performance fibres such as aramid fibres or, for less hostile environments, polyester fibres. The free ends of the fibres are joined by stitching and/or gluing (16). Stitching and/or gluing the ropes together avoids the need for swaging, reduces the damage to the fibres that would be caused by swaging and allows a greater range of fibres to be successfully formed into cable stockings (10).

Description

1 "Improvements in cable stockings" Cross-Reference to Related Applications The present application claims priority from Australian provisional patent application No 2011902738, filed on 7 June 2011, entitled "Improvements in cable 5 stockings" the content of which is incorporated herein by reference. Field of the Invention This invention relates to an improved cable stocking. 10 Background of the Invention Cable stockings, also known as cable socks, hose restraints and whip checks (and generally referred to hereinafter by the term cable stocking) are devices for gripping, lifting or restraining a cable/hose or the like, to apply, or relieve, an axial load. Cable stockings are designed to securely grip cables without damaging the same. 15 They are made in a number of different configurations including single eye, double eye, offset eye, lace up or no-eye, and also with a number of different weave configurations including over-one under-one or over-one under-two. Due to the helical weave of the braid, a cable stocking shrinks radially when an axial load is applied to the ends of the stocking. Hence the stocking's grip on the 20 cable/hose increases as the axial load applied to the stocking increases. Hence it is a characteristic of a cable stocking that tension applied to the stocking results in elongation of the stocking and contraction onto a cable or the like around which the cable stocking is located. Cable stockings are used in many applications particularly in the electricity, 25 mining, construction and telecommunications industries, particularly for electrical and fibre optic installation, pulling, hauling, restraining and supporting cables and hoses. Cable stockings are most commonly made of galvanised or stainless steel wire rope. At at least one end of the cable stocking, and in some cases at both ends, there are free ends of the wire that need to be terminated/joined together to inter alia prevent 30 the stocking from unravelling. This is typically done by swaging. There are problems with wire stockings in that the wire ends project slightly from the swaging or splicing which is necessary to enable one to check if the ferrule is slipping. The same problem occurs with back-weaving in that the ends are exposed. The projecting wires can cause needle spike injuries. Needle spike injuries can also occur when wire rope 35 fatigues/wears in general use and the individual wires break and stick out. Other materials have been considered for cable stockings but in some environments the 2 materials which can be used are limited due to WHS and other requirements. For example Aluminium cannot be used in underground mining. For some applications it would be desirable to use fibres rather than metal wires however, problems arise in joining the fibres to form a stocking. Many fibres have to 5 be coated to provide resistance to UV, abrasion, or fire and these coatings in particular do not join well using traditional joining and terminating methods for cable stockings such as swaging. Swaging can also weaken some fibres. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that 10 any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application. Summary of the Invention 15 According to the present invention, there is provided a cable stocking or the like having a first end and a second end arranged such that when an axial tension is applied to the stocking, it results in elongation and contraction of the stocking wherein the stocking comprises a weave, braid, or plait of ropes made from non-metallic fibres and wherein free ends of the fibres are joined by stitching and/or gluing. 20 Stitching and/or gluing the ropes together avoids the need for swaging, reduces the damage to the fibres that would be caused by swaging and allows a greater range of fibres to be successfully formed into cable stockings. The ropes may be coated with a fire retardant or abrasion resistant coating. The ropes may be overlapped and joined to each other, to other ropes or to 25 webbing or the like. In one embodiment, the ropes may be located inside a length of tubing, typically formed from webbing, and stitched and/or glued to the tubing, and optionally to each other also. The ropes may be turned through 1800 to form loops or eyes. 30 The cable stockings may be provided as any one or more types including single eyes, double eyes, the eyes may or may not be offset, the stockings may be no-eyes or double ended. The eyes may be made of rope, cord, tubing or webbing, either flat round and with or without protective sleeving. 35 Various different fibres could be used and while the preferred fibres are synthetic polymers, such as aramids and polyethylene and minerals such as tenax, 3 natural fibres could also be used. For use in mining applications, the fibres need to be heat, chemical and abrasion resistant and strong. Fire resistance, chemical and abrasion resistance may be provided by an external coating on the rope. It is preferred, particularly for mining applications that the ropes are woven from 5 high performance fibres, which are generally characterised by remarkable unit tensile strength and resistance to heat, flame and chemical agents that normally degrade conventional fibres. High performance fibres are typically derived from rigid-rod polymers, gel spun fibres, modified carbon fibres, synthetic vitreous fibres, and poly(phenylene sulphide) fibres. 10 Where natural fibres are used these could include animal fibres such alpaca, angora, byssus, camel hair cashmere, catgut, chiengora, guanaco, llama, mohair, pashmina, qiviut, rabbit, silk sinew, spider silk, wool, vicuna, yak or plant fibres such as abaca, bamboo, coir, cotton, flax, hemp, jute, kapok, kenaf, pina, raffia palm, ramie, sisal or wood, or natural mineral fibres such as asbestos. 15 Where synthetic fibres are used these could include cellulose based fibres such as acetate, triacetate, art silk, lyocell rayon (tencel), modal rayon or rayon. Suitable mineral fibres may include glass, carbon (tenax), basalt and metallic fibres. Suitable polymer based fibres include acrylic, aramid (Twaron, Kevlar, Technora, Nomex), microfibers, modacrylic, nylon, olefin, polyester, polyethylene (Dyneema, spectra), 20 spandex, vinylon, vinyon, zylon. Whatever fibres are used these should have a minimum ultimate tensile strength (UTS) of at least 750Mpa. A larger UTS is preferred preferably greater than 1 OOOMPa, more preferably at least 1200MPa. In a preferred embodiment the fibres will have a UTS in the order of 1400MPa. 25 The fibres may be formed by braiding, plaiting, spinning, weaving or the like into a round rope or flat rope, cord or webbing or tubing. Brief Description of the Drawings Specific embodiments of the present invention will now be described, by way of 30 example only, and with reference to the accompanying sketched drawings in which: Figure 1 shows overlapping ropes from opposing directions joined with glue and/or stitching; Figure 2 shows overlapping ropes from similar direction joined with glue and/or stitching; 35 Figure 3a shows a plan view of ropes forming an eye joined with glue and/or stitching; 4 Figure 3b shows a side view of the eye of Figure 3a; Figure 4 shows a further eye formed by an alternative method; Figure 5a shows a side view of multiple ropes touching a single rope to form an overlapping section, joined with glue and/or stitching method; 5 Figure 5b shows an end view of the arrangement of Figure 5a; Figure 6a shows a side view of multiple ropes meeting a single rope turned back to form eye and create an overlapping section; Figure 6b shows an end view of the arrangement of Figure 6a; Figure 7 shows ropes from opposing directions overlapping flat webbing and 10 joined; Figure 8a shows a similar view to Figure 7 prior to a folding over of the webbing; Figure 8b shows the webbing and ropes of Figure 8a turned back to form an eye and joined; 15 Figure 9a shows ropes from opposing directions overlapping flat webbing and joined; Figure 9b shows the arrangement of Figure 9a in which the webbing is folded over lengthways and joined; Figure 10 shows ropes from opposing directions laid over a length of webbing to 20 form an overlapping section and joined; Figure 11 shows ropes from opposing directions laid inside a length of tubing to form an overlapping section and joined; Figure 12 shows ropes from opposing direction overlapping inside tubing and joined; 25 Figures 13A to 13E illustrated various examples of cable stockings/hose restraints; and Figure 14 shows various examples of cable stockings/hose restraints with eye termination at both ends (double end). 30 Detailed Description of Preferred Embodiments For the avoidance of doubt, as used herein, the term cable stocking should be taken to include cable stockings, cable socks, hose restraints, whip checks, stockings and socks. The object to be gripped by the cable stocking may include cables, hoses, ropes 35 of any similar elongate generally cylindrical object.

5 Referring to the drawings, Figure 13 to 14 show schematically various types of cable stockings. These can be woven from different numbers of ropes/cords of fibre replacing the wires previously used. The term rope as used herein may include ropes, cords, webbing, strands or similar. The weave, braid or plait patterns to form metallic 5 wires into cable stockings are well known and these same patterns can be used for the fibre ropes. The characteristic weave/plait of a cable stocking results in a sheath for a cable such that when an axial tension is applied to the stocking/sheath, it results in elongation of the stocking and contraction onto a cable or the like around which the stocking is located. 10 Cable stockings may be plaited/woven from differing numbers of ropes, typically ranging from three to thirty-six, with eight, ten, twelve and eighteen being most common. The maximum diameter of the cable stocking will vary depending on the size of the hose, cable or the like to which the stocking is to be fitted. The cable stockings/hose restraints can be terminated in different styles depending on the 15 application. Figure 13A shown a cable stocking 200 (type A) which is open at one end 201 and closed at the other end 202 and has a single eye termination 204. Only the eye end 202 of the cable stocking needs to be terminated as at the open end 201, the ropes are turned through 180" and do not need to be joined together, although as an alternative 20 means of termination may also be terminated as this end. The stocking may also be joined to another stocking at this end to make a stocking of longer length. Or a longer stocking may be cut down to make two or more shorter stockings. Figure 13B shows a cable stocking 205 (type B) which is open at both ends and has a simple open end 206 at one end and double off-set eyes 208, 210 at the other open 25 end. Figure 13C shows a flat lace up cable stocking 212 (type C) weave with double off-set eyes 214, 216. Lace up stockings are not tubular when placed over a cable but are flat and are wrapped around the cable and the longitudinal edges are laced together. Figure 13D shows a cable stocking 220 (type D) which is open at both ends 222, 30 224. Figure 13 E shows a cable stocking 226 (type R) which is open at both ends 228, 230 and has a single off-set eye 232. Figure 14 shows further three different examples of cable stockings/hose restraints 240, 250, 260 having eye terminations 262 at both ends. 35 As discussed in the introduction, at at least one end of the cable stocking, and in some cases at both ends, there are free ends of the rope that need to be 6 terminated/joined together to inter alia prevent the stocking from unravelling. Typically there will be from three to thirty-six or more free ends depending on how many separate ropes are used to plait the stocking. With cable stockings made from wire, this termination is done by swaging. However for ropes made of synthetic and 5 natural fibres, swaging is not reliable. Hence the ropes are joined to each other by stitching and/or gluing. Various options for stitching and/or gluing the rope ends together are shown in Figures I to 12. Figure 1 shows an array 10 of six ropes 12 from one direction and six 14 from 10 an opposite direction. They are overlapped at their ends to create an overlapped section 18 and joined with glue and/or stitching 16. Figure 2 shows an arrangement in which two arrays 22, 24 of six ropes from similar directions, intersecting at an angle of about 300 and overlapping at their ends in a triangular overlapped zone 25, joined with glue and/or stitching 26, 15 Figures 3a and 3b show six ropes 30 turned back on themselves to form an eye 32 and overlapping section 34, in which the overlapping section is joined with glue and/or stitching 36. Figure 4 shows six ropes 40 turned back to form an eye 41 and create an overlapping section 42 with ropes from opposing direction, joined with glue and/or 20 stitching 43. Figures 5a and 5b show multiple ropes 50 touching a single parallel rope of relatively larger diameter 52 to form an overlapping section 54 and joined with glue and/or stitching 55. Figures 6a and 6b show multiple ropes 60 touching a single rope 61 turned back 25 through 1800 to form an eye 62 and create an overlapping section 64 and joined with glue and/or stitching 65. Figure 7 shows six parallel ropes 70 from opposing directions overlapping a piece of flat webbing 72 in two separate areas 74, 76 and joined to the webbing with glue and/or stitching 78. 30 Figure 8a shows an array of parallel ropes 80 and 82 from opposing directions overlap a piece of flat webbing 84 and joined to the webbing with glue and/or stitching in two separate areas 86 and 88. Figure 8b shows the webbing 84 and ropes turned back to form eye, and joined with glue and/or stitching 89. Figure 9a shows an array of parallel ropes 100, 102 from opposing directions 35 overlapping a large sheet of flat webbing 104 and joined with glue and/or stitching 105 7 at two corners 106, 108 of the sheet. Figure 9b shows the webbing 104 folded over lengthways and joined with glue and/or stitching. Figure 10 shows two arrays of six parallel ropes 100, 102 from opposing directions laid over a length of webbing 104 to form overlapping section 106 where the 5 arrays overlap each other and the webbing joined with glue and/or stitching 108. Figure 11 shows two arrays of six parallel ropes 110, 112 from opposing directions laid inside a length of tubing 113 (typically formed from webbing) to form an overlapping section 114 and joined with glue and/or stitching 116 to each other and the tubing. 10 Figure 12 shows two arrays of six parallel ropes 120, 122 from opposing directions overlapping a length of tubing 124 and joined with glue and/or stitching to the tubing at two separate overlapping areas 126, 128 by stitching and/or gluing 129. The length of the cable stocking may vary depending on the application but for mining applications for hose restraints, lengths of 0.5m to 5m are common, and the 15 stockings commonly cover the entire length of the hose. As discussed above, various different fibres could be used and while the preferred fibres are synthetic polymers, such as aramids and polyethylene and minerals such as tenax, natural fibres could also be used. For use in mining applications, the fibres need to be heat, chemical and abrasion resistant and strong. Fire resistance, 20 chemical and abrasion resistance may be provided by an external coating on the rope. It is preferred, particularly for mining applications that the ropes are woven from high performance fibres, which are generally characterised by remarkable unit tensile strength and resistance to heat, flame and chemical agents that normally degrade conventional fibres. High performance fibres are typically derived from rigid-rod 25 polymers, gel spun fibres, modified carbon fibres, synthetic vitreous fibres, and poly(phenylene sulphide) fibres. Rigid rod polymers are typically liquid crystalline polymers classified as lyotropic, such as the aramid Kevlar, or thermotropic liquid crystalline polymers such as "Vectran". One well known lyotropic aramid fibre is poly(p-phenylene 30 terephthalamide) (PPT) marketed by DuPont as "Kevlar". Akzo also market a suitable aramid fibre under the name "Twaron". Another suitable fibre is marketed by Teijin Ltd as "Technora" which is a wholly aromatic copolyamide of PPT modified with a crankshaft -shaped comonomer. Heterocyclic rigid-rod polymers include PBZ, a family of p-phenylene 35 heterocyclic rigid-rod and extended chain polymers including poly(p-phenylene -2,6- 8 benzobisthiazole) (trans-PZBT) and poly(p-phenylene-2,6-benzobisoxazole) (cis PBO). Nomex fibre and Poly(2,2'-(m-phenylene )-5,5'-bisbenzimidazole) (PBI) are also known heterocyclic rigid-rod polymers, as are Industrial thermotropic LCPs such as 5 "Vectran" poly(6-hydroxy-2-napthoic acid-co-4-hydroxybenzoic acid) Gel spun fibres are high performance polyethylene fibres (HPPE) sold under the trade names of "Dyneema" and "Spectra 1000". Modified carbon fibres are fibres in which the precursor fibres are only partially carbonised to produce carbon fibres which are easier to weave or knit. 10 Man made vitreous fibres (MMVF) include a number of glass, specialty glass and refractory ceramic fibres. Glass fibres are made of glass forming compounds such as SiO 2 and P 2 0 5 mixed with other intermediate oxides such as A1 2 0 3 , TiO 2 and modifiers or fluxes such as MgO, BaO, K 2 0 and others. The three common glass compositions are referred to as E, S and AR glasses. E glass is most suitable for 15 making fibres for ropes. Sulphur (sulfar) fibres are known as Ryton fibres. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present 20 embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

1. A cable stocking having a first end and a second end arranged such that when an axial tension is applied to the stocking, it results in elongation and contraction of the stocking wherein the stocking comprises a weave, braid, or plait of ropes, the ropes 5 being made from non-metallic fibres and wherein free ends of the ropes are joined by stitching and/or gluing.

2. A cable stocking as claimed in claim 1 wherein the ropes are coated with a fire retardant or abrasion resistant or chemical resistant coating. 10

3. A cable stocking as claimed in claim 1 or claim 2 wherein the ropes are overlapped and joined to each other by stitching and/or gluing.

4. A cable stocking as claimed in claim 1 or claim 2 wherein the ropes are 15 overlapped and each rope is joined to itself by stitching and/or gluing.

5. A cable stocking as claimed in claim 1 or claim 2 wherein the ropes are overlapped and each rope is joined to another rope by stitching and/or gluing. 20

6. A cable stocking as claimed in any one of claims 1 to 5 wherein the ropes are overlapped and stitched and/or glued to a piece of material, such as webbing.

7. A cable stocking as claimed in claim 1 or claim 2 wherein, the ropes are located inside a length of tubing, and are stitched and/or glued to the tubing, and/or to each 25 other.

8. A cable stocking as claimed in any preceding claim wherein the ropes are turned through 180" to form loops or eyes at one or both ends of the cable stocking. 30

9. A cable stocking as claimed in any preceding claim wherein the ropes comprise high performance fibres as herein defined.

10. A cable stocking as claimed in any preceding claim wherein the ropes comprise 35 fibres selected from the group comprising rigid-rod polymers, gel spun fibres, modified carbon fibres, synthetic vitreous fibres, and poly(phenylene sulphide) fibres. 10

11. A cable stocking as claimed in claim 9 or 10 wherein the fibres have a minimum ultimate tensile strength (UTS) of at least 750Mpa.

12. A cable stocking as claimed in claim 9 or 10 wherein the fibres have a minimum 5 ultimate tensile strength (UTS) of at least 1000MPa.

13. A cable stocking as claimed in claim 9 or 10 wherein the fibres have a minimum ultimate tensile strength (UTS) of at least 1200MPa. 10

14. A cable stocking as claimed in any preceding claim wherein the ropes comprise fibres of lyotropic or thermotropic liquid crystal polymers or heterocyclic or heterocyclic rigid-rod polymers.

15. A cable stocking as claimed in any one of claims 1 to 14 wherein the ropes 15 comprise gel spun fibres.

16. A cable stocking as claimed in any one of claims 1 to 14 wherein the ropes comprise modified carbon fibres. 20

17. A cable stocking as claimed in any one of claims 1 to 14 wherein the ropes comprise man made vitreous fibres.

18. A cable stocking as claimed in any one of claims 1 to 14 wherein the ropes comprise sulfar fibres. 25

19. A cable stocking as claimed in any one of claims 1 to 8 wherein the ropes comprise polyester fibres.

20. A cable stocking as claimed in any one of claims 1 to 8 wherein the ropes 30 comprise aramid fibres.