Rope made of textile fiber material, comprising a twine of excess length

Abstract

The invention relates to a rope made of textile fiber material, comprising a rope core and a sheath surrounding the rope core, wherein the sheath, an intermediate sheath located between the sheath and the rope core and/or a reinforcement located between the sheath and the rope core comprise(s) a twine of excess length, the twine of excess length being formed in that it comprises at least a first yarn and a second yarn which are twisted together, the first yarn having a greater length than the second yarn, measured in an untwisted state of a unit length of the twine. In a further aspect, the invention relates to a method of manufacturing a twine of excess length for the above-mentioned rope.

Claims

1. A rope made of textile fiber material, comprising: a rope core; and a sheath surrounding the rope core; wherein the rope comprises a twine of excess length, the twine of excess length being formed so that it comprises at least a first yarn and a second yarn which are twisted together, the first yarn having a greater length than the second yarn, measured in an untwisted state of a unit length of the twine of excess length, wherein the twine of excess length is present in at least one of: the sheath, an optional intermediate sheath located between the sheath and the rope core, an optional reinforcement located between the sheath and the rope core.

2. A rope according to claim 1, wherein the first yarn comprises high-strength fibers.

3. A rope according to claim 1, wherein the first yarn comprises p-aramid fibers, m-aramid fibers, LCP fibers, UHMWPE fibers or PBO fibers.

4. A rope according to claim 1, wherein the second yarn comprises non-high-strength fibers.

5. A rope according to claim 1, wherein the second yarn comprises PA fibers, PES fibers or PP fibers.

6. A rope according to claim 1, wherein the first yarn is at least 5% longer than the second yarn, measured in the untwisted state of the unit length of the twine.

7. A rope according to claim 1, wherein the first yarn is at least 12% longer than the second yarn, measured in the untwisted state of the unit length of the twine.

8. A rope according to claim 1, wherein the weight proportion of the first yarn in the twine of excess length is 30% to 90%.

9. A rope according to claim 1, wherein the weight proportion of the twine of excess length in the sheath, in the intermediate sheath and/or in the reinforcement, in each case, accounts for 50% to 100% of the sheath, the intermediate sheath or the reinforcement, respectively.

10. A rope according to claim 1, wherein the rope core is constructed from one or several twisted or braided cores.

11. A rope according to claim 1, wherein the rope core comprises non-high-strength fibers.

12. A rope according to claim 1, wherein the rope core comprises PA fibers, PES fibers or PP fibers.

13. A rope according to claim 11, wherein the rope is configured as a climbing rope according to the EN892 standard.

14. A rope according to claim 1, wherein the rope core comprises high-strength fibers.

15. A rope according to claim 1, wherein the rope core comprises aramid fibers, UHMWPE fibers or PBO fibers.

16. A rope according to claim 1, wherein the diameter of the rope is 5 mm to 60 mm.

17. A rope according to claim 1, wherein the diameter of the rope is 5 mm to 13 mm.

18. A method of using a rope according to claim 11, comprising a user placing and using the rope as a climbing rope.

19. A method of manufacturing a rope according to claim 1, comprising the steps of: a) manufacturing a twine of excess length by: providing the first yarn and the second yarn; twisting the first yarn with the second yarn; wherein the first yarn and the second yarn are twisted together with essentially the same tension and the same length and the twine is subjected to a shrinking process after twisting; or wherein the first yarn and the second yarn are twisted together with different tensions and the twine is relaxed after twisting. b) manufacturing the rope by: introducing a rope core into a braiding machine and forming a sheath around the rope core, wherein the sheath, an intermediate sheath located between the sheath and the rope core and/or a reinforcement located between the sheath and the rope core comprises the twine of excess length.

20. A method according to claim 19, wherein the shrinking process is performed in an autoclave.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Advantageous and non-limiting embodiments of the invention are explained in further detail below with reference to the drawings.

[0056] FIG. 1 shows the cross-section of the rope according to the invention.

[0057] FIG. 2 shows a twine of excess length incorporated in the rope of FIG. 1.

[0058] FIG. 3 shows the twine of FIG. 2 in the untwisted state.

[0059] FIG. 4 shows a test setup for determining the cut resistance.

DETAILED DESCRIPTION OF THE DRAWINGS

[0060] FIG. 1 shows the cross-section of a rope 1. The rope 1 comprises a rope core 2 and a sheath 3 surrounding the rope core 2. The rope 1 is made of a textile fiber material, i.e., both the rope core 2 and the sheath 3 are made of a textile fiber material. The rope 1 is preferably designed so as to be free of metal, apart from optional connecting elements or clamps that are attached to the ends of the rope 1 or at another point on the rope 1, or functional, electrically conductive wires that are guided within the rope 1 and serve, for example, as conductors, data lines or sensors.

[0061] Optionally, the rope 1 may have an intermediate sheath 4 provided between the rope core 2 and the sheath 3. Depending on the embodiment, this intermediate sheath 4 may also be made of textile fiber material and designed so as to be free of metal. As an alternative or in addition to the intermediate sheath 4, a textile, preferably metal-free, reinforcement (not illustrated) may also be used, which herein is understood to be a non-covering intermediate sheath.

[0062] As can be seen in FIG. 1, the rope core 2 comprises twelve cores 5. In general, however, the rope core may also have only one core 5 or more than one core 5. The cores 5 are, for example, twisted or braided, but might also be produced in another way.

[0063] The rope 1 described herein can be used for various intended purposes, for example as a mountaineering rope, as a rope for connecting means, for loops or as a winch rope. If it is used as a mountaineering rope, the rope 1 is employed, for example, by a climber as a fall protection or is also used as a static accessory cord for makeshift rescue techniques. If it is used as a rope for connecting means, a tree maintenance professional, for example, can employ the rope 1 as a connecting means/lanyard, with the rope 1 looped around the tree 1 and hooked into a harness of the tree maintenance professional so that the tree maintenance professional is able to support themselves in any vertical position on the tree. If intended to be used as a rope for loops, the rope 1 is employed as an auxiliary rope for climbing. If intended to be used as a winch rope, said rope is wound onto a winch and, in contrast to the aforementioned uses, is therefore employed in a mechanical operation and not for protecting people from falling.

[0064] In all above-mentioned applications, the rope 1 can have a diameter ranging from 5 mm to 60 mm, preferably from 5 mm to 13 mm.

[0065] Especially when the rope 1 is used to prevent falls, the rope core 2 should have advantageous dynamic properties. In such embodiments, the rope core comprises non-high-strength fibers, preferably polyamide (PA) fibers. In other applications, the non-high-strength fibers may also be polyester (PES) fibers or polypropylene (PP) fibers.

[0066] In other embodiments, for example when the rope 1 is employed as a winch rope, the rope core 2 can, however, also comprise high-strength fibers. For the purposes of the present invention, “high-strength” is understood to mean fibers with a tensile strength of at least 14 cN/dtex, preferably a tensile strength greater than 24 cN/dtex, particularly preferably greater than 30 cN/dtex. For example, UHMWPE fibers (including Dyneema®), aramid fibers, LCP fibers (including Vectran) or PBO fibers are known as high-strength fiber types with appropriate tensile strengths.

[0067] Depending on the embodiment, the rope core 2 or the cores 5 may also comprise a mixture of high-strength fibers and non-high-strength fibers.

[0068] In order to increase the cut resistance of the rope 1, said sheath 3, the intermediate sheath 4 and/or the reinforcement comprise(s) the twine 6 of excess length Δ, which will be explained below with reference to FIGS. 2 and 3. The sheath 3, the intermediate sheath 4 and/or the reinforcement can be manufactured completely or partially from several twines 6 of excess length Δ. The sheath 3 and the intermediate sheath 4 are usually braids so that several twines 6 of excess length Δ can be braided together, optionally with other twines being added. Usually, however, the weight proportion of the twine 6 of excess length Δ in the sheath 3, in the intermediate sheath 4 and/or in the reinforcement, in each case, accounts for 50% to 100%.

[0069] In FIG. 2, the twine 6 of excess length Δ is illustrated, which can be produced in an indefinite length and wound onto at least one bobbin prior to the production of the sheath 3, the intermediate sheath 4 or the reinforcement. In addition, an arbitrarily chosen unit length E of the twine 6 of excess length Δ is depicted in FIG. 2. The numeric quantity of the unit length E can be chosen as desired, for example 1 m. However, the invention is completely independent of the actually chosen length, as will be explained below, and serves only for determining the excess length Δ of the yarn 7 in the twine 6 of excess length Δ.

[0070] As is known to a person skilled in the art, twines are produced by twisting several yarns. The twine 6 of excess length Δ as described herein comprises a first yarn 7 and a second yarn 8 which are twisted together. The twisted state of the twine 6 of excess length Δ is illustrated in FIG. 2.

[0071] FIG. 3 shows the section of the unit length E of the twine 6 of excess length Δ in an untwisted state. It can be seen that the first yarn 7 has a greater length than the second yarn 8. In a practical example, E=1 m was chosen for the unit length. However, as can already be seen in FIG. 2, the first yarn 7 is twisted with the second yarn 8 so that, in parts, small loops of the first yarn 7 form around the second yarn 8.

[0072] As can be seen in FIG. 3, the actual length of the first yarn 7 in the untwisted state is greater than the length of the second yarn 8 or the unit length E, respectively. In the above example, in which the unit length E=1 m was chosen, a length L1=1.15 m resulted for the first yarn 7 and a length L2=1 m resulted for the second yarn 8 in the untwisted state of the twine 6 of excess length Δ. In this example, the first yarn 7 is thus 15% longer than the second yarn 8 in the untwisted state of the twine 6 of excess length Δ, the percentage P being calculated by way of P=100*(L1−L2)/L2.

[0073] It is evident from the above example that the choice of the unit length E is arbitrary and is used only for determining the relative length of the first yarn 6 in relation to the second yarn. If the unit length E=2 m was chosen, the length L1 of the first yarn 7 in the untwisted state of the twine 6 of excess length Δ would be 2.3 m and the length L2 of the second yarn 8 would be 2 m so that the first yarn 7 would again be 15% longer than the second yarn 8.

[0074] In general, the first yarn 7 is at least 5%, preferably at least 8%, particularly preferably at least 12%, longer than the second yarn 8, measured in the untwisted state of the unit length E of the twine 6. As described above, the percentage P is, in each case, indicated with respect to the length L2 of the second yarn 8, i.e., P=100*(L1−L2)/L2. As a result of those length ratios, it is achieved that the first yarn 7 is not yet extended even when the second yarn 8 is stretched. An upper limit to the length by which the first yarn 7 is longer than the second yarn 8 can be, for example, 30%, this upper limit usually only being limited by the manufacturing method.

[0075] At this point, it should be noted that the measurement of the length of the first yarn 7 and the second yarn 8 in the untwisted state of the unit length E can occur either in the tension-free state or under a certain pretension, e.g., 0.5+/−0.1 cN/tex. The pretensioning of the yarns may be necessary in order to achieve a correct, comparable measuring result. Standards for measuring the length of yarns are known from the prior art, such as, e.g., DIN 53830-3, which, among other things, specifies a pretension of 0.5+/−0.1 cN/tex for measuring the length of yarns, and may also be used for determining the lengths of the yarns of the rope 1 described herein.

[0076] Usually, the first yarn 7 comprises high-strength fibers and the second yarn 8 comprises non-high-strength fibers, with the definition of high-strength being given, as above, with regard to the rope core 2. For example, the high-strength fibers of the first yarn 7 may be p-aramid fibers (para-aramid fibers), m-aramid fibers (meta-aramid fibers), LCP fibers, UHMWPE fibers or PBO fibers. Fibers sold under the names Kevlar, Twaron and Technora are particularly suitable. For the non-high-strength fibers of the second yarn 8, PA fibers, PES fibers or PP fibers may be chosen, for example.

[0077] Depending on the embodiment, yarns 7, 8 of different materials can thus be chosen for the twine 6 of excess length Δ. In other embodiments, however, yarns made from the same materials may also be chosen, although there may be restrictions due to the manufacturing methods as described below.

[0078] Usually, the ratio of the first yarn 7 to the second yarn 8 is chosen such that the weight proportion of the first yarn 7 of excess length Δ accounts for 30% to 90%, preferably 40% to 75%, in the twine.

[0079] However, the structure of the twine 6 is not restricted to the twisting of only two yarns, but more than two yarns might also be twisted together. In the untwisted state of the twine 6 of excess length Δ, all the yarns might then have different lengths. Also, in other embodiment variants, only one yarn could be longer than the other yarns of the same length, or only one yarn could be shorter than the other yarns of the same length. Again, for example, two yarns of the same length could be longer than two other yarns of the same length. It is apparent that there are no limits to the structure of the twine 6 of excess length Δ as long as at least one yarn has a greater length than another yarn, measured in an untwisted state of a unit length E of the twine 6. In those embodiments, it is particularly preferred if the longest yarn is at least 5%, preferably at least 8%, particularly preferably at least 12%, longer than the shortest yarn, measured in the untwisted state of the unit length E of the twine 6.

[0080] The twine 6 of excess length Δ can be produced in a wide variety of ways and is not limited to a specific manufacturing method. In particular, however, manufacturing methods performed by means of a shrinking process or under different tensions are appropriate and are described below.

[0081] In the manufacturing method using a shrinking process, the first yarn 7 and the second yarn 8 are provided first. In this case, the two yarns 7, 8 are usually provided without tension or with equal tensions. Thereupon, the yarns 7, 8 are plied together, resulting in a twine without excess length Δ. In a further process step, the twine without excess length Δ is exposed to a predetermined temperature in an autoclave after an appropriate preparation, e.g., knitting, so that the first yarn 7 and the second yarn 8 shrink. In this embodiment, the yarns 7, 8, in particular their materials, were chosen such that they shrink to different degrees under the predetermined conditions, resulting in the twine 6 of excess length Δ.

[0082] In the manufacturing method using different tensions, the first yarn 7 and the second yarn 8 are plied together with different tensions, and the twine 6, i.e., its yarns 7, 8, is relaxed after plying. The choice of the tensions for achieving a desired amount of excess length Δ of the first yarn 7 compared to the second yarn 8 can be determined by a person skilled in the art on the basis of the modulus of elasticity of the two yarns 7, 8. It is apparent that, for example, a twine in which PA 940 dtex is plied with aramid 1660 dtex always requires a different pretension for obtaining the twine 6 of excess length Δ than a twine in which PA1400 dtex is plied with aramid 1660 dtex.

[0083] In order to empirically test whether the above-illustrated rope 1 with the twine 6 of excess length Δ processed therein has a higher cut resistance than a comparable rope without a twine 6 of excess length Δ, the measurement described below was performed. It goes without saying, however, that other measuring methods may also be used for determining the cut resistance.

[0084] Initially, a height-adjustable test carrier was provided on which a granite block 9 having a length of 80 cm and comprising a naturally broken edge 10 (a pavement edge made of granite) was attached. Starting from a fixed anchor point located thereabove, a test mass (a steel cylinder of 80 kg) was lowered over the edge 10 with the rope to be tested. Due to the position of the anchor point, a deflection of the rope occurs at the edge 10 at a deflection angle α, as can be seen in FIG. 4. The edge 10 is located at a distance of 4 m from the anchor point (the stand). Immediately after the edge 10, the test mass is freely suspended. By installing a load cell, the forces occurring at the anchor point were recorded.

[0085] The test procedure is as follows:

[0086] A load cell is installed at the anchor point and the test rope is attached to it.

[0087] In each case, the mass is suspended from the test rope in a shock-free manner just below the stone edge and is then lowered by 2 m.

[0088] The rope is moved horizontally by means of pulleys attached to the side (This could correspond to a situation in which the lowered climber swings sideways to the next stand located underneath). The test rope is thus pulled along the sharp edge 10 in both directions until it breaks. The edge length that was swept over until the break occurred is measured and referred to as the breaking length.

[0089] In order to achieve a lateral movement as uniform as possible, the force of the lateral pull is introduced directly below the edge 10. Stop bolts at the respective end of the edge 10 prevent the rope from moving beyond the edge 10. At the end of the tests, the sharpness of the edge 10 is verified by a rope model that has already been tested. In this case, the edge 10 remained unchanged.

[0090] The first test rope was a state-of-the-art rope, designed according to EN892 with a diameter of 9.8 mm. This was a core-sheath rope with a polyamide sheath. The deflection angle was 45°. A breaking length of approx. 200 cm was achieved.

[0091] The second test rope was a rope according to the invention with aramid in the intermediate sheath in the construction according to the invention, designed according to EN892 with a diameter of 9.8 mm. A breaking length of approx. 340 cm was achieved. In this way, the breaking length was increased by 70% in comparison to the state-of-the-art rope.