EP2476801B1 - Combined rope made of artificial fibres and steel wire strands and combined strand of artificial fibres and steel wires - Google Patents

Description

The invention relates to a combined rope with a core rope with high-strength plastic fibers and an outer layer of steel wire strands, wherein the core rope is enclosed by a sheath which is provided in addition to an outer layer.

Furthermore, the invention relates to a combined stranded wire with a core strand of high strength plastic fibers and an outer layer of steel wires, wherein the core strand is enclosed by a sheath provided in addition to the outer layer.

A combined rope and a combined strand of the type mentioned go out of the US 6,563,054 B1 out. The plastic fibers of the core rope or the core strand extend parallel to one another in the longitudinal direction of the rope or the strand and are held together by a deformable sheath of thermoplastic material. The outer layer is formed of steel wire strands or steel wires.

Another combined rope and another combined strand are from the GB 1 557 391 A known. On a core rope formed from aramid fibers is directly on an outer layer of steel wire strands or steel wires on.

The US 2006/0137896 A1 describes an elevator belt assembly having a plurality of stretched strands and including a jacket over the stretched strands that holds the strands in the stretched condition.

From the EP 1 083 254 A2 For example, there is a cord for actuating window shutters whose braid is made of yarns under tension and provided with a polyurethane sheath which is hardened.

Another combined rope is from the US 4,887,422 known. The rope has a sheathing of a core rope which is extruded or wound up.

Further, by use, in particular for sporting purposes, ropes having a braid protecting the synthetic fibers are known.

The advantage of the high-strength plastic fibers is their low weight and volume compared to their strength both in the independent ropes and in the combined ropes and strands.

This advantage is particularly effective for long-length ropes for hanging use, such as mining ropes or deep-sea ropes. For in such an application, the weight of a pure wire rope already claimed itself a large part of its carrying capacity; the payload is limited accordingly.

Advantage of the combined rope over the pure plastic rope is its significantly lower sensitivity to mechanical interference. In addition, it can be seen on the visible wire breaks the Ablegereife a wire rope in good time.

While the breaking strength of high strength plastic fibers, eg aramid copolymer 3470 N / mm ² , aramid HM (high modulus) 2850 N / mm ² , aramid HS (high strenth) 3350 N / mm ² , aramid SMS (standard modulus) 2850 N / mm ² , HMPE 3400 N / mm ² and Liquid Crystal Polyester 2800 N / mm ² , which exceeds that of steel wire, eg 1770 N / mm ² , and thus can contribute decisively to the load bearing capacity of a combined rope, but the strains differ in this way high degree that under the known rope constructions hardly a rope structure can be found, in which the core rope made of plastic can take a significant share of the load bearing. The elastic moduli of the above fiber materials are 73, 120, 60, 60, 85 and 65 GPa, respectively, to average 200 GPa of steel wires. Above all, there is the fact that the actual load absorption of the plastic fibers begins with a delay, because the monofilament bundles first have to "settle" with each load, ie have to find a final spatial allocation to form a stable bundle cross section.

The invention has for its object zuschaffen a combined rope or a combined strand of the type mentioned, whose or the plastic fibers have an arrangement which deviates from a parallel orientation in the longitudinal direction of the rope or the strand, and in which the core rope or the core strand has a large effective load capacity.

According to the invention, this purpose concerning the combined cable or strand of the type mentioned above is achieved by providing the core strand as a single twisted monofilament bundle or a plurality of monofilament bundles and stretching the monofilament bundle under reduction in diameter and in that state is held by the sheath or are.

Like a corset, the sheath fixes the cross-section of the monofilament bundle assumed during said stretching.

Is that or sin the monofilament bundles stretched so far that the plastic fibers have found their final spatial allocation to form a stable bundle cross-section, the process of "setting" before and at the beginning of the load shots is at least largely eliminated, it is completed once and for all , The normal load absorption under elastic stretching of the plastic fibers according to Hooke's law can start immediately.

In the combined rope, the stretching behavior of the core rope is thus approximated to that of the steel wire layer.

An independent rope has the same carrying capacity, for example, reduced by 10% diameter, ie a greater load capacity based on the diameter.

As a variant and a particularly advantageous development of the invention, it is proposed to approximate the stretching behavior of the steel wire layer of a combined rope to that of the core rope made of synthetic fibers by subjecting the steel wire layer to the reversal version of the invention taken on the core rope: it is to be able to stretch under load and to do so permitting variable cross-section.
The concrete measure of invention in this version is that the cable has an intermediate layer of an elastic plastic, in which the wire strands are pressed with a distance from each other, such that the outer layer stretches under load and contracts radially.
The elastic compliance of the intermediate layer and the distance of the wire strands from each other make it possible to stretch the helices described by the strands by increasing their pitch, with their diameter and accordingly reduces the strand spacing.
Due to the elasticity of the plastic, the process is reversible when relieved, so the desired effect with each new load absorption available.

The advantages of the former version and the reverse version of the invention can each be used individually, but with great success, together.

Analogous to the combined rope, a combined strand can be created. At the point of the core wire of the strand is then just as the core rope of the strand ausgestaltetes, but correspondingly thinner rope. (The term "rope" includes strands of monofilament bundles, regardless of structure.)

As the sheath mentioned is particularly suitable a braid. In a Fleehtmaschlne the monofilament bundles can be easily stretched by being driven at the output of the machine, for example by a pair of rollers for their movement and are retained at the entrance of the machine, for example by means of a braked pair of rollers, and the braid can be performed with a bias. However, wrapping is also an option.
If necessary, the expansion can also be effected by reducing the cross-section.

The said intermediate layer is usually, as in the art propagated, be extruded, possibly on the said sheath. A standardization of the sheathing and the intermediate layer would be difficult in that both serve different purposes and must therefore have different properties. The sheathing should be as unyielding as possible, the intermediate layer should be soft. Foamed plastic is also considered for the intermediate layer.
Suitable materials for the sheath are, for example, polyester fibers, suitable materials for the intermediate layer are polyurethanes, polyesters, polyolefins and polyamides.

Finally, as a particularly advantageous application of a core rope according to the invention, a combined rope is mentioned for hanging use over a large height difference, in particular with a lower end held against rotation, in particular a hoist rope, deep-sea rope or cableway rope which is characterized by change in length over the rope length in that the load-specific torque of the wire rope decreases upward.

A wire of this structure is known from the DE 36 32 298 , Conveniently, in such a wire rope, the decrease of the load-specific torque is dimensioned such that it increases the weight of the Wire rope up in the effect on the torque substantially compensates. Preferably, in the case of such a wire rope having only one lilac layer, the lay length of the strand layer increases upward. Appropriately, in the case of such a plurality of strand layers having the same direction of impact wire rope, the lay length of at least the outer layer of strands, preferably also that of the interior or of the uppermost strand layer, increases towards the top. Furthermore, it can be provided that, in the case of such a wire strands having a plurality of strand layers of different directions of impact, the lay length of the outer strands layer stranded in the reverse direction as the inner or the next inner strands layer decreases upward and / or the lay length of the inner strands layer (n ) increases upward. Conveniently, in the case of such a plurality of strand layers of different directions having wire rope, the lay length of the wire layers in the strands of the outer, stranded in the reverse direction as the next strand strand stranded strand layer upwards and / or in the strands of the inner Lilzenlage (n) , wherein preferably the specific load absorption in Sell cross section at the upper end of the rope is approximately uniform. Further, in such a wire rope, the stroke length change may be made in steps.

With the above-mentioned stroke length changes caused by the rope weight twists within the rope structure can be avoided, in particular further twists of the strand layer in the lower region of the rope, which would seek to shorten the rope there and thus counteract the load of the core rope.

Fig. 1

ist ein Last-Dehnungs-Diagramm verschiedener Materialien,

Fig. 2

ist ein Last-Dehnungs-Diagramm einer normal verseilten und einer erfindungsgemäß auf einer elastischen, weichen Zwischenschicht verseilten Stahldrahtlage,

Fig. 3

ist ein Last-Dehnungs-Diagramm eines Kernseiles aus Kunststofffasern für ein kombiniertes Stahldraht-Kunststofffaser-Seil mit und ohne erfindungsgemäße Ummantelung,

Fig. 4

ist ein Last-Dehnungs-Diagramm des Kernseiles und der Drahtseillage eines kombinierten Seiles wie nach Fig. 5,

Fig. 5

zeigt einen Querschnitt eines kombinierten Seiles mit einem Kernseil aus Kunststofffasern und einer Außenlage aus Stahldrahtlitzen und

Fig. 6

zeigt einen Querschnitt eines Fig. 5 entsprechenden Seiles mit anderen Litzen.

In the following, the invention will be explained in more detail by way of examples.

Fig. 1

is a load-elongation diagram of different materials,

Fig. 2

FIG. 2 is a load-elongation diagram of a normally stranded and a steel wire layer stranded on an elastic, soft intermediate layer according to the invention, FIG.

Fig. 3

FIG. 3 is a load-elongation diagram of a core rope of plastic fibers for a combined steel wire-plastic fiber rope with and without sheath according to the invention, FIG.

Fig. 4

is a load-elongation diagram of the core rope and the wire rope layer of a combined rope as below Fig. 5 .

Fig. 5

shows a cross section of a combined rope with a core rope of plastic fibers and an outer layer of steel wire strands and

Fig. 6

shows a cross section of a Fig. 5 corresponding rope with other strands.

In Fig. 1 the relevant materials are each noted directly on the curves. The steel wire follows Hooke's Law only in the lower load range because it is made by drawing and therefore does not have the normal structure. The use is usually only about in the lower half of the curves.

In Fig. 2 you can find the curve of the steel wire in Fig. 1 in the normally stranded strand layer (upper curve) again. The lower curve shows the effect of embedding the strands according to the invention in a soft intermediate layer: up to about 0.6% elongation, the curve runs approximately horizontally. The elongation here is that the helixes of the coiled strands elongate, reducing the diameter of the helices, almost without load-bearing of the strands. The load pickup sets in afterwards.

How out Fig. 3 can be seen, the above-mentioned, pronounced up to 0.5% and then decreasing, but noticeably still up to about 1% elongation effecting act of setting (lower curve) largely by the sheath invention eliminate (upper curve). The upper curve increases in contrast to the lower from the beginning, although the final proportional slope according to the Hooke's law only about between 0.5 and 1% elongation occurs.

The application of both invention measures in a combined rope as after Fig. 5 is out Fig. 4 seen. Here are the lower curve of the Fig. 2 and the upper curve of the Fig. 3 close to each other.

In cross-section of the rope construction Fig. 5 the inventive measures can only be seen insofar as a sheath 2 of a core rope 1 and also an intermediate layer 3 are shown, in which an outer layer of steel wire strands 4 is pressed.
The core rope 1 is within the sheath 2 of a monofilament bundle or more monofilament bundles, which are only twisted so much that they have cohesion and can be handled. The sheath 2 consists of a braid of preferably polyester threads. It sits with a bias on the Monofilbündel or monofilament bundles, which holds them together after an elongation in the set state.
The intermediate layer 3 is extruded over the sheath 2 of the core rope 1 in a conventional manner. It consists of a soft-elastic plastic, such as polyethylene or polypropylene.

The steel wire strands 4 are stranded over and pressed eg in the still warm intermediate layer 3 such that they have each their own bed with some distance from each other.
The intermediate layer 3 is so elastic-soft and the steel wire strands 4 have such a distance from each other (slightly larger than in the drawing), that the position of the steel wire strands 4 under load initially somewhat lengthy and their diameter is reduced. The strain curves ( Fig. 4 ) of the strand layer and the core rope are thereby approximated to each other, ie the load bearing is distributed approximately corresponding to the cross sections of the strand layer and the core rope.

The rope according to Fig. 6 has the same basic structure as the one according to Fig. 5 with a core rope 1, a braided sheath 2, an extruded intermediate layer 3 and an outer algae of here designated 5 strands. The strands 5 have an analog to the rope structure again with a thinner, core 6 of high strength plastic fibers, a braided sheath 7, an extruded intermediate layer 8 made of a soft elastic plastic and an outer layer of steel wires 9. The rope has due to its larger Plastic cross-section the advantage of even lower weight, but it is also robust with the steel wires in the outer layer.
The intermediate layer 3 could also be omitted in this rope, since the outer strands 5 already have an increased elasticity in itself.

Claims (12)

1. Combined cable having a core cable (1) with high-strength synthetic fibres and an outer layer of steel wire strands (4; 5), wherein the core cable is enclosed by a sheathing (2) which is provided in addition to the outer layer, characterized in that the core cable (1) is in the form of a single twisted bundle of monofilaments or a plurality of twisted bundles of monofilaments, and the bundle or bundles of monofilaments is or are stretched, with a reduction in diameter, and held in this state by the sheathing (2).
2. Combined cable according to Claim 1, characterized in that the bundle or bundles of monofilaments is or are stretched such that the synthetic fibres have found their final spatial order, forming a stable bundle cross section, and a cross section of the bundle of monofilaments that is assumed in the stretched state is held by the sheathing (2).
3. Combined cable according to Claim 1 or 2, characterized in that the combined cable has an intermediate layer (3) of an elastic synthetic material into which the steel wire strands (4; 5) are pressed while spaced apart from one another, such that the outer layer extends under load, and contracts radially.
4. Combined strand having a core strand (6) with high-strength synthetic fibres and an outer layer of steel wires (9), wherein the core strand (6) is enclosed by a sheathing (7) which is provided in addition to the outer layer, characterized in that the core strand (6) is in the form of a single twisted bundle of monofilaments or a plurality of twisted bundles of monofilaments, and the bundle or bundles of monofilaments is or are stretched, with a reduction in diameter, and held in this state by the sheathing (2).
5. Combined strand according to Claim 4, characterized in that the bundle or bundles of monofilaments is or are stretched such that the synthetic fibres have found their final spatial order, forming a stable bundle cross section, and a cross section of the bundle of monofilaments that is assumed in the stretched state is held by the sheathing (7).
6. Combined strand according to Claim 4 or 5, characterized in that the combined strand has an intermediate layer (3) of elastic synthetic material into which the steel wires (9) are pressed while spaced apart from one another, such that the outer layer extends under load, and contracts radially.
7. Combined cable according to one of Claims 1 to 3, characterized in that an outer strand (5) of the combined cable is formed by a combined strand according to one of Claims 4 to 6.
8. Combined cable according to Claim 3 or combined strand according to Claim 6, characterized in that the intermediate layer (3; 8) is extruded on.
9. Combined cable according to Claim 3 or 7, when dependent on claim 3 or 8, or combined strand according to Claim 6 or 8, characterized in that the intermediate layer (3; 8) is formed from a foam plastic, a polyurethane, a polyester, a polyolefin or a polyamide.
10. Combined cable according to Claim 1, 2, 3, 7, 8 or 9 for suspended use over a difference in height, characterized by changing of the length of lay over the length of the cable, such that the load-specific torque of the wire cable decreases upward.
11. Combined cable according to Claim 10, characterized in that the combined cable is a cable car cable.
12. Use of the combined cable according to Claim 10 as a hoisting cage cable, deep-sea cable or cable car cable.

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