EP3325710B1 - Rope made of textile fibre material - Google Patents

Description

The present invention relates to a rope made of textile fiber material for applications in which diagonal pull can occur.

It is known that ropes are twisted about their longitudinal axis in applications where diagonal pull occurs.

In the rope drives of cranes, but also in other applications, the arrangement of the rope sheaves often means that the ropes run up and down at a lateral deflection angle when running over the rope sheaves. The lateral rope deflection angle that occurs between the rope and the sheave is also called the diagonal pull angle.

In particular, it is known that non-rotation-free laid ropes tend to untwist under load due to their "helix" if they are not torsionally rigidly fastened on both sides.

However, ropes that are essentially rotation-free (e.g. designed in such a way that the torques of the individual rope elements, such as strands, cancel each other out under load) can also be twisted when diagonal pull occurs.

The expert understands torsion-prone ropes as all ropes whose torsion is < 360°/1000d when not torsionally rigid attachment under a load of S/d ² = 0 to S/d ² = 150 N/mm ² , where d is the diameter of the means rope (Feyrer 2000, wire ropes, Springer Verlag).

Depending on the rope construction, a twisting of the rope around its longitudinal axis leads to a redistribution of the load between the load-bearing elements (wires, fibers, strands, etc.). As a result of this load redistribution, individual elements are relieved and other elements are overloaded. The service life of the rope is reduced as a result of this load redistribution between the supporting elements.

This twisting of the rope can occur locally, for example in applications with diagonal pull, e.g. in the case of multiple reeving in pulley blocks or an oblique pull-off from the drum to the first deflection sheave and can therefore also affect rotation-free ropes.

In fact, rotation-resistant ropes in particular lose their service life, more than non-rotation-resistant ropes, since the load redistribution between the individual strand layers is more pronounced due to the different directions of lay of the strand layers ( Source: Weber, Tobias: Contribution to the investigation of the service life behavior of wire ropes under a combined stress of tension, bending and torsion. Dissertation University of Stuttgart, 2013, print-on-demand, full text: http://elib.uni-stuttgart.de/opus/volltexte/2013/8663 ).

Since diagonal pull cannot be avoided structurally in many applications, the highest possible torsional rigidity is desired to prevent local torsion (consequence on service life, see above).

the WO 2015/001476 describes a flexible cable for furling a sail. The core of the cable, which can consist of fiber material, is covered with rubber, which includes fiber strands running in different directions. The rubber is vulcanized, resulting in a strong bond between the core of the cable and the rubber layer.

From the EP 2 868 917 A1 a tension cable for a wind power generation system using an aircraft is known. Spirals are arranged around the core of the cable, which can optionally include signal strands or electrical strands.

the CA1234520 describes the manufacture of a cable in which parallel filaments are compacted and then completely wrapped with a tape so as to be protected against an externally applied polyurethane coating.

From the U.S. 7,399,018 a rope sling is known which, particularly in the area of the splice, is surrounded by a spirally cut open tube made of polyurethane.

Further prior art is from U.S. 2009/282801 A1 , the U.S. 2,737,075 A , the WO 2006/118465 A1 , the DE 200 21 529 U1 as well as the WO 98/50621 known.

The object of the present invention is to provide a rope made of textile fiber material which is better protected against twisting when diagonal pull occurs.

This object is solved by a rope according to claim 1 or claim 2. Preferred embodiments of the cable according to the invention result from the dependent claims.

BRIEF DESCRIPTION OF THE FIGURES

• figure 1 shows schematically a preferred embodiment of the winding of the core of the cable according to the invention.
• figure 2 shows schematically a two-layer winding of the core.
• figure 3 shows schematically the test method for determining whether the gap between two windings provided in a preferred embodiment is sufficiently large.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a rope made of textile fiber material for applications in which diagonal pull can occur, available, which is characterized in that the rope is a core/sheath rope, the core and the sheath of which consist essentially of textile fiber material Core is stranded or braided and the core and / or if the core is in the form of several strands, at least a part of the strands, preferably all strands of the core, is positively wound with a tension element / are. The term "rope made of textile fiber material" means that the main components of the rope, in particular its supporting elements, are made of textile fiber material, such as strands made of synthetic fibers. The rope according to the invention can also have components made of other materials, such as materials impregnating the rope or rope components, or also individual non-textile strands with a special function, e.g. for the transmission of electrical signals.

The core and the sheath of the rope essentially consist of textile fiber material, although additional materials such as individual non-textile strands are also possible here.

The core of the rope according to the invention is stranded, ie the strands forming the core of the rope are twisted together. Alternatively, the strands of the core can be braided.

The core of the cable according to the invention can be present as a single core, ie as a single strand of strands that are twisted or braided together. Alternatively, the core may be in the form of multiple strands. The strands can run parallel to one another or, in turn, be twisted or intertwined with one another. According to the invention, a tension element is wound around the core in a non-positive manner. This winding is therefore present between the core and the cladding.

This winding ensures that the rope twists as little as possible when it is used, especially if it is pulled diagonally.

"Tension element" and "force-locking winding" means elements and their attachment that prevent twisting of the rope as far as possible.

The twisting of the cable should only be prevented by winding the core with the tension element. Further impregnation of the rope is possible, but not necessary.

1. a) Es ist der gesamte Kern (also alle Stränge gemeinsam) umwunden
2. b) Es sind zumindest ein Teil der Stränge, bevorzugt sämtliche Stränge, einzeln umwunden
3. c) Eine Kombination von a) und b)

If the core consists of several strands, as shown above, the winding can be in the following ways:

1. a) The entire core (i.e. all strands together) is wound around
2. b) At least some of the strands, preferably all strands, are wound individually
3. c) A combination of a) and b)

According to the invention, the tension element is wound around the core of the rope or optionally the strands of the core with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tension element.

Because of this pretension, a particularly effective non-positive winding can be achieved to prevent the cable from twisting.

According to the invention, at least one winding with a gap to the next winding is present within a winding layer. It has been shown that spacing the individual turns is advantageous since the rope is more flexible.

The windings do not have to be spaced by gaps over the entire length of the rope. It is important that gaps are provided in that area of the rope which will be bent during use (e.g. over a drum or traction sheave).

In a preferred embodiment of the present invention, the pulling element is wound in at least two winding layers around the core of the cable or, if appropriate, the strands of the core. The wrapping layers can particularly preferably differ in terms of their wrapping direction.

In the case of two winding layers, one layer can thus be wound around the cable in the "S" direction and the second layer applied above it in the "Z" direction.

The gap between two windings should preferably be selected at least large enough that it does not close when the cable bends with a bending radius of five times the outer diameter of the cable on the side of the cable that shortens during the bend.

Mathematically, this can be expressed by the following formulas:
The starting point is the winding length W, which results from the width of the tension element plus the gap between two windings.

wobei die Abkürzungen folgende Bedeutungen haben:

• W_n = Windelänge des Zugelementes in der n-ten Lage der Umwindung in mm
• B_n = Breite des Zugelementes in der n-ten Lage der Umwindung in mm
• L_n = Lücke des Zugelementes zwischen zwei benachbarten Umwindungen in der n-ten Lage der Umwindung in Prozent.

The gap L is defined as a component of the winding length W or, in the case of several winding layers, as a component of the respective winding length Wn in the _nth layer of winding as follows: $$W_n=B_n*\left(1+L_n\right),$$

where the abbreviations have the following meanings:

• W _n = winding length of the tension element in the nth layer of winding in mm
• B _n = width of the tension element in the nth layer of the winding in mm
• L _n = gap of the tension element between two adjacent wraps in the nth layer of the wrap in percent.

wobei die Abkürzungen folgende Bedeutungen haben:

• L_n bedeutet die Lücke zwischen zwei Umwindungen der selben Umwindelage in %,
• D bedeutet den Durchmesser einer Vorrichtung, z.B. einer Scheibe, um welche das Seil gebogen wird, wobei D der zehnfache Wert des Außendurchmessers d_a des Seils ist,
• d_n bedeutet den jeweiligen Außendurchmesser des Kerns samt Umwindelagen bis zur n-ten Lage, die umwunden wird
• n: Anzahl der Lagen des Umwindematerials
• d_a bedeutet den Außendurchmesser des Seiles mit Mantel

According to the preferred implementation of the gap, the percentage value of the gap is then: $$L_n>\left\{\left[\frac{D+\frac{{\mathrm{i.e}}_n}{2}}{D}\right]-1\right\}*100=\left\{\left[\frac{10{\mathrm{i.e}}_a<figure-callout\; id="2"\; label="+\; i.e\; n"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">+</figure-callout>\frac{{\mathrm{i.e}}_n}{}\frac{{}_{}}{2}}{10{\mathrm{i.e}}_a}\right]-1\right\}*100,$$

where the abbreviations have the following meanings:

• L _n means the gap between two wraps of the same wrap layer in %,
• D denotes the diameter of a device, e.g. a pulley, around which the rope is bent, where D is ten times the outer diameter d _a of the rope,
• d _n means the respective outer diameter of the core including the winding layers up to the nth layer that is wound
• n: number of layers of wrapping material
• d _a means the outer diameter of the rope with sheath

All length specifications are to be entered in mm.

The winding length W or W _n does not have to be constant over the length of the rope. As mentioned above, it is particularly advantageous if gaps are provided in the area of the rope that is bent during use, which gaps then preferably satisfy the above formulas. No gaps or gaps that do not satisfy the above formulas can be provided at other points.

In a further preferred embodiment, at least 30%, preferably at least 50%, particularly preferably at least 80% of the surface of the core of the rope or possibly the strands of the core are covered by the winding or the windings with the tension element within a winding layer.

The tension element provided according to the invention is particularly preferably in the form of a band.

The width of the band B is preferably from 0.5 ^* d _n to 2 ^* d _n .

The width of the tape can be constant across the different wrap layers. Alternatively, tapes of different widths can be used. For example, a tape with a different width than that of the previous wrapping layer can be used for each wrapping layer.

• µ den Gleitreibungskoeffizient zwischen zwei Lagen des Zugelements und
• S die maximale Zugkraft des Seiles
• bedeuten.

The tension element provided according to the invention preferably has a tensile strength of F _min ≥μ ^* S, where

• µ is the coefficient of sliding friction between two layers of the tension element and
• S the maximum tensile force of the rope
• mean.

The material of the core of the rope according to the invention consists preferably of high-strength fibers. The fibers can be selected from the fiber types UHMWPE, Aramid, LCP, PBO, PET, PA, PP, PE and mixtures thereof.

Likewise, the material of the sheath of the rope according to the invention preferably consists of high-strength fibers, which can be selected from the fiber types UHMWPE, aramid, LCP, PBO, PET, PA, PP, PE and mixtures thereof.

The material of the tension element can be selected from the fiber types UHMWPE, Aramide, LCP, PBO, PET, PA, PP, PE and mixtures thereof. Band-shaped traction elements are preferably in woven form.

The diameter of the cable according to the invention is 6 mm and more, in particular up to 200 mm and more.

The rope according to the invention is preferably characterized in that it is twisted by less than 10°/100d when loaded between 0% and 40% of its actual breaking load (according to ISO 2307), where d is the diameter of the rope with sheath in mm.

Methods with the features according to claim 11 or 12 are used to produce the cable according to the invention.

According to the invention, the tension element is wound around the core of the cable or optionally the strands of the core with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tension element.

Also preferably, the core of the rope or possibly the strands of the core is kept under pretension during winding with the traction element, in particular at a pretension of 0.1% to 40% of the breaking load of the core or possibly the strands of the core.

The present invention also relates to the use of the rope according to the invention in applications where diagonal pull can occur, in particular as a carrying/hauling rope in cranes, e.g , e.g. drilling rigs, piling rigs and cable excavators.

DETAILED DESCRIPTION OF THE FIGURES

figure 1 shows a preferred embodiment of the rope according to the invention. Only the core 1 of the rope is shown schematically. The core 1 has a diameter d _o and consists of twisted or braided textile fiber material (not shown). In a manner known per se, the rope also has a sheath made of textile fiber material, which is not shown here. According to the invention, the core 1 is wound with a tension element 2, which is in the form of a strip in the preferred embodiment shown here. The winding 2 is in the finished rope between the core 1 and the sheath (not shown).

Gaps with a width L ₁ are provided between the turns. As a result, the windings have a winding length W ₁ which results from the width B ₁ of the tension element 2 and the gap L ₁ . The surface of the core 1 is 50% or more, in particular 80% or more, covered by the tension element.

Together with this winding layer, the diameter of the wound core 1 is d ₁ .

figure 2 1 shows an embodiment with two winding layers 2' and 2". The winding layers 2' and 2" are wound around the core 1 in different winding directions. Gaps are provided between the respective windings in both winding layers. A winding length W ₂ thus also results in the second wrapped layer from the width B ₂ of the tension element in this wrapped layer and the gap L ₂ in this wrapped layer. Furthermore, the diameter of the wound core 1 is d ₂ .

As mentioned above, the width B ₁ and B ₂ of the tension element can be different in the two wrapping layers, as can the length of the gaps L ₁ and L ₂ . In addition, the length of the gaps L ₁ and L ₂ must be constant over the length of the cable, but can vary or, in particular, no gaps can be provided at locations on the cable that are not bent during use.

figure 3 shows schematically the measurement method by which it can be determined whether the provided gaps L ₁ have the preferred minimum length according to the invention: the core 1 wound with the tension element 2 is bent over an element, eg a disc 3 . The diameter D of the disk 3 is 10 times the outer diameter of the rope with the sheath d _a (not shown). If the gaps L ₁ do not close when the cable is bent over the sheave 3 on the side that shortens during the bend, then they have the required minimum length and also meet the formulas given above.

Claims (15)

1. A rope made of a textile fibre material for applications in which a diagonal pull may occur, wherein the rope is a core/sheath rope, the core (1) of which and the sheath of which are composed essentially of a textile fibre material, wherein the bundles forming the core (1) are twisted or braided with each other, characterized in that the core (1) is enwound by a tensile element (2, 2', 2") in a force-fitting manner, wherein the tensile element (2, 2', 2") is wound around the core (1) of the rope with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tensile element (2, 2', 2"), wherein, within a winding layer (2', 2"), a winding is located with a gap (L₁, L₂) from the next winding.
2. A rope made of a textile fibre material for applications in which a diagonal pull may occur, wherein the rope is a core/sheath rope, the core (1) of which and the sheath of which are composed essentially of a textile fibre material, wherein the the core (1) of the rope comprises several strands, wherein a strand is composed of bundles which are twisted or braided with each other, characterized in that the core (1) is provided in the form of several strands, which run in parallel or are twisted or braided with each other, and at least a part of the strands, preferably all of the strands of the core, is/are enwound by a tensile element (2, 2', 2") in a force-fitting manner, wherein the tensile element (2, 2', 2") is wound around the core of the rope with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tensile element (2, 2', 2"), wherein, within a winding layer (2', 2"), a winding is located with a gap (L₁, L₂) from the next winding.
3. A rope according to claim 2, wherein the whole core (1) is enwound by a further tensile element (2, 2', 2") in a force-fitting manner, which is wound around the core (1) of the rope with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tensile element (2, 2', 2").
4. A rope according to any of the preceding claims, characterized in that the tensile element (2) is wound around the core of the rope or, respectively, optionally the strands of the core in at least two winding layers (2', 2").
5. A rope according to claim 4, characterized in that the winding layers (2', 2") differ in their directions of winding.
6. A rope according to any of the preceding claims, characterized in that the gap (L₁, L₂) between two windings is chosen to be at least large enough so that it will not close when the rope is bent at a bending radius of five times the diameter of the rope on the side of the rope which becomes shorter with bending.
7. A rope according to any of the preceding claims, characterized in that at least 30%, preferably at least 50%, particularly preferably at least 80% of the surface of the core (1) of the rope or, respectively, optionally the strands of the core of the winding or windings (2, 2', 2") is covered by the tensile element.
8. A rope according to any of the preceding claims, characterized in that the tensile element (2, 2', 2") is provided in the form of a band.
9. A rope according to any of the preceding claims, characterized in that the tensile element (2, 2', 2") has a tensile strength of F_min≥ µ^∗S, wherein
   µ denotes the coefficient of sliding friction between two layers of the tensile element, and S denotes the maximum tensile force of the rope.
10. A rope according to any of the preceding claims, characterized in that, under a load of between 0% and 40% of its actual breaking load, the rope is twisted by less than 10°/100d, wherein d denotes the diameter of the rope including the sheath.
11. A method for the manufacture of a rope according claim 1, optionally in combination with any one of claims 4 to 10, wherein the rope is a core/sheath rope, the core (1) of which and the sheath of which are composed essentially of a textile fibre material, wherein the bundles forming the core (1) are twisted or braided with each other, characterized in that the core (1) is enwound by a tensile element (2, 2', 2") in a force-fitting manner, wherein the tensile element (2, 2', 2") is wound around the core (1) of the rope with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tensile element (2, 2', 2"), wherein, within a winding layer (2', 2"), a winding is located with a gap (L₁, L₂) from the next winding.
12. A method for the manufacture of a rope according claim 2, optionally in combination with any one of claims 3 to 10, wherein the rope is a core/sheath rope, the core (1) of which and the sheath of which are composed essentially of a textile fibre material, wherein the the core (1) of the rope comprises several strands, wherein a strand is composed of bundles which are twisted or braided with each other, characterized in that the core (1) is provided in the form of several strands, which run in parallel or are twisted or braided with each other, and at least a part of the strands, preferably all of the strands, is/are enwound by a tensile element (2, 2', 2") in a force-fitting manner, wherein the tensile element (2, 2', 2") is wound around the core (1) of the rope with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tensile element (2, 2', 2"), wherein, within a winding layer (2', 2"), a winding is located with a gap (L₁, L₂) from the next winding.
13. A method according to claim 12, wherein the whole core (1) is enwound by a further tensile element (2, 2', 2") in a force-fitting manner, which is wound around the core (1) of the rope with a pretension of at least 1%, preferably at least 2%, particularly preferably at least 3% of the maximum tensile force of the tensile element (2, 2', 2")
14. A method according to any one of claims 11 to 13, characterized in that the core (1) of the rope or, respectively, optionally the strands of the core is/are kept at a pretension of 0.1% to 40% of the breaking load of the core or, respectively, optionally the strands of the core, during the enwinding with the tensile element (2, 2', 2").
15. The use of a rope according to any of claims 1 to 10 in applications in which a diagonal pull may occur, in particular as a suspension/hauling rope in cranes, for example, tower slewing cranes, mobile cranes, crawler cranes and offshore cranes, in hoisting winches, in particular for single-strand lifting of unguided loads and in construction equipment, for example, drilling equipment, ramming equipment and cable dredges.

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