Rope and method for producing a rope

Abstract

A method for producing a rope, wherein fiber bundles are applied with a liquefied matrix material upstream of and/or at a twisting point to form fiber strands, and are embedded into the liquefied matrix material during stranding, by which fiber strands a fiber core of the rope is formed and wires or wire strands are wound about the fiber core. The matrix material of the fiber strands is hardened after the stranding, and the fiber strands are subsequently stranded directly with one another without further application to form the fiber core. Preferably the fiber strands are heated, during or after the stranding thereof to form the fiber core, so that the matrix material softens at least individual of the fiber strands, preferably all the fiber strands, softens and connects with the matrix material of another of the fiber strands, and is subsequently hardened, forming an integral bond with one another.

Claims

1. A method for producing a rope, comprising the steps of: coating fiber bundles with a liquefied matrix material at least one of before and at a twisting point when forming fiber strands; stranding the fiber bundles to form the fiber strands and embedding the fiber bundles in the liquefied matrix material during stranding; solidifying the matrix material of the fiber strands after the stranding; subsequently stranding the fiber strands directly with one another without a further coating of matrix material to form a fiber core of the rope; and winding wires or wire strands around the fiber core, further including heating the fiber strands, during or after stranding thereof to form the fiber core, so that the matrix material softens at least individual of the fiber strands and binds to the matrix material of other respective fiber strands, and the fiber strands then solidify, forming an integral bond with one another.

2. The method according to claim 1, wherein all of the fiber strands are softened.

3. The method according to claim 1, including providing a sheath on the fiber core, the sheath being formed from the matrix material.

4. The method according to claim 3, wherein the wires or the wire strands are embedded in the matrix material of the sheath.

5. The method according to claim 1, wherein the fiber strands are parallel-stranded or layer-stranded to form the fiber core.

6. The method according to claim 1, wherein during layer stranding, the fiber strands are stranded in different lay directions in order to influence torque generated on loading of the rope so that the fiber core or the entire rope is rotation-resistant or rotation-free.

7. The method according to claim 1, including stranding the fiber strands in regular lay, in which fibers in the fiber strands and the fiber strands in the rope are wound in opposite directions, and in long lay, in which the fibers in the fiber strands and the fiber strands in the rope are wound in a common direction.

8. The method according to claim 1, wherein before stranding onto the fiber core, the wires or the wire strands are preformed into a helical or approximately helical shape, which the wires or wire strands assume in the finished rope.

9. The method according to claim 8, wherein only a single layer of the preformed wire strands is wound around the fiber core.

10. The method according to claim 8, wherein at least two layers of the wire strands are wound around the fiber core.

11. A rope, comprising a fiber core having fiber strands, wherein the fiber strands are formed from fiber bundles embedded in a matrix material, stranded with one another in the matrix material; and stranded onto the fiber core are wires or wire strands, wherein the fiber strands are directly stranded with one another in the fiber core without additional coating of matrix material, wherein the matrix material bonds the fiber strands of the fiber core to form an integral bond between the respective fiber strands and the fiber strands are fused to one another.

12. The rope according to claim 11, wherein a sheath is formed on the fiber core and the wires or wire strands are embedded in the sheath.

13. The rope according to claim 12, wherein the sheath is composed of the matrix material.

14. The rope according to claim 11, wherein the fiber strands of the fiber core are parallel-stranded or layer-stranded.

15. The rope according to claim 11, wherein the fiber strands are layer stranded in different lay directions in order to influence torque generated on loading of the rope so that the fiber core or the entire rope is rotation-resistant or rotation-free.

16. The rope according to claim 11, wherein the fiber strands are stranded in regular lay, in which fibers in the fiber strands and the fiber strands in the rope are wound in opposite directions, and in long lay, in which the fibers in the fiber strands and the fiber strands in the rope are wound in a common direction.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 schematically shows a device for carrying out the method according to the invention,

(2) FIG. 2 shows a detail of the device according to FIG. 1 in an isometric view,

(3) FIG. 3 schematically shows a further device for carrying out the method according to the invention, and

(4) FIGS. 4-9 show sections of various ropes according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(5) In order to carry out the method, wound bundles 2 of fibers, composed for example of aramid or polyethylene, are first stranded into a fiber strand 3 by means of the stranding device 9 shown in FIG. 1. For this purpose, the fiber bundles 2 are conveyed by means of a rotatable stranding basket 10 to a twisting point 4 at which they are wound into the fiber core strand 3. Spools, not shown here, onto which the fiber bundles 2 are wound, are arranged in a manner known per se on the stranding basket 10. In production of the fiber strand 3, the fiber bundles 2 are continuously unwound from the spools as the stranding basket 10 rotates. By means of rollers 16, the fiber strand 3 is pulled from the twisting point 4 and wound onto a drum 17 for further use.

(6) As shown in FIG. 1, and as can be seen more specifically in FIG. 2, the fiber bundles 2 are surrounded by a container 11 at the twisting point 4 to which a thermoplastic, such as polypropylene, can be fed via a heatable line 14 from an extruder 13. On its side facing the stranding basket 10, the container 11 is provided with a rotatable side wall 18 that has a plurality of openings 19 through which the fiber bundles 2 can be fed into the container 11. By means of a projection. 12, which is rigidly connected to the stranding basket 10, the rotatable side wall 18 is carried along by the stranding basket 10 when the stranding basket 10 rotates, A fiber bundle 2, which forms a strand core in the fiber strand 3, can also be fed through the projection 12 into the container 11.

(7) On a side of the container 11 opposite the side wall 18, a further opening is provided, through which the fiber strand 3 composed of the fiber bundles 2 can be discharged from the container 11. The opening has a diameter and a shape that are equivalent to the diameter or shape of the fiber strands 3 to be formed.

(8) In order to produce the fiber strand 3, the fiber bundles 2, in the respectively required number, arrangement, and size or in the required structure, are continuously wound with one another at the twisting point 4 with rotation of the stranding basket 10 and the movable side wall 18. In this process, the liquefied polypropylene is continuously fed into the container 11. This coats the fiber bundles 2 before and during stranding, so that the fiber bundles 2 in the fiber core strand 3 are embedded in the thermoplastic.

(9) After the fiber strand 3 is discharged from the opening of the container 11, it is cooled in a water bath 15 or simply in the air in order to cool and thus solidify the thermoplastic, and it is then wound onto the drum 17.

(10) Using a number of the fiber strands 3 produced in this manner, fiber cores 6 see FIG. 3) of any desired structure can be produced using the conventional stranding devices by parallel stranding or layer stranding of the fiber strands 3, for example according to the above-mentioned general formation law for spiral ropes or in the mentioned rope constructions such as Seale, Filler, Warrington, etc.

(11) FIG. 3 schematically shows a conventional stranding device 20 on which a heating device 22 is provided. By means of the heating device 22, the fiber strands 3 are heated before, at and/or after the twisting point 21 such that the thermoplastic in the fiber strands 3 becomes so soft that it melts together with other fiber strands 3 and forms a single-part fiber core 6 after cooling.

(12) In layer stranding, heating of the fiber strands 3 can be provided either in stranding of individual or all of the fiber strand layers 31, 32 or only in stranding of the last fiber strand layer 32 (cf. rope shown in section in FIG. 4).

(13) After this, wire strands 7 are stranded onto the fiber core 6, for example as shown in FIG. 3 by means of a tandem stranding machine, and a rope according to the invention 1 is formed. Preferably the wire strands 7 are stranded onto the fiber core 6 for as long as the thermoplastic 5 remains soft. The wire strands 7 are then pressed into the thermoplastic 5, are embedded therein, and a positive-locking connection is formed between a wire strand layer 71 lying directly on the fiber core 6 and the fiber core 6.

(14) Alternatively, the wire strands 7 can be stranded when the thermoplastic 5 of the fiber core 6 has already solidified. In this case, the wire strands 7 are only positioned on the fiber core 6.

(15) Optionally, the wire strands 7 can be preformed prior to stranding, preferably into a helical or approximately helical shape, which they assume in the rope 1 when it is completed.

(16) This makes it possible to produce the rope 1 with low internal stresses, and optionally even without any internal stresses.

(17) In the production of the fiber strands 3, a sufficiently large amount of thermoplastic 5 can be provided in the fiber strands 3 so that during heating of the stranded fiber core 6, a sheath 8 of the thermoplastic 5 forms on the fiber core 6 in which wire strands 7 can be embedded.

(18) Alternatively, an additional layer of thermoplastic 5 can be provided on the fiber core 6 in order to take up the wire strands 7.

(19) FIG. 4 shows a sectional view of a rope 1 produced by means of the method described above, which has a fiber core 6 of fiber strands 3 of the same diameter and the same structure. In layer stranding, the fiber core 6 is stranded in a 1+6+12 structure, wherein a first layer 31 of six fiber strands 3 is stranded in a clockwise (Z lay) direction and a second layer 32 of 12 fiber strands 3 is stranded in a counterclockwise (S lay) direction. As the fiber strands 3 are stranded in the Z lay direction, the layer 32 is stranded in regular lay and the layer 31 in long lay.

(20) As shown in FIG. 4, the fiber strands 3 are fully embedded in the thermoplastic 5. The layer of wire strands 7 lying on the fiber core 6 is embedded in a sheath 8, which has formed from the thermoplastic 5 and surrounds the fiber bundles 3 of the fiber core 6. The wire strands 7 are wound onto the fiber core 6 with a lay angle such that the torques generated by the fiber strands of the fiber core 6 and by the wire strands 7 cancel each other out on loading of the rope 1. The lay lengths of the fiber core 6 and the wire strands 7 can be adapted to each other such that rope 1 is rotation-resistant, for example with a rotational characteristic of one rotation of the rope <3.6/1000 d rope length on lifting of a load equivalent to 20% of F.sub.min, or is rotation-free.

(21) In the following, reference is made to FIGS. 5 through 9, in which parts that are identical or have the same action are designated with the same reference numbers as in FIGS. 1 through 4 and a letter is added to the relevant reference number respectively.

(22) A rope 1d shown in FIG. 8 differs from that according to FIG. 4 in that only a single layer of wire strands 7d is provided, the wire strands 7d of the single layer are wound onto the fiber core 6d with a lay angle such that the torques generated by the fiber strands 3d of the fiber core 6d and by the wire strands 7d on loading of the rope 1d cancel each other out, and as described above, the wire strands 7d are preformed into a helical shape. Because of this preforming, on the one hand, the wire strands 7d exert relatively little force on the fiber core 6d. On the other hand, the rope 1d is cut-proof, i.e. it does not unravel under its own internal stresses when it is cut. The rope 1d is also rotation-resistant and can have the rotational characteristic described above for the rope 1.

(23) A rope 1a shown in FIG. 5 differs from the rope 1 according to FIG. 4 in that a fiber core 6a is parallel-stranded and has a 1+6+(6+6) structure (Warrington). Fiber strands 3a, 3b of an outer layer 32a of fiber strands 3a have different diameters. In the case of rope 1a as well, the lay lengths of the fiber core 6a and the wire strands 7a are adapted to one another such that the rope 1a is rotation-resistant, for example with a rotational characteristic of one rotation of the rope <3.6/1000 d rope length on lifting of a load equivalent to 20% F.sub.min, or is rotation-free.

(24) In contrast to the rope 1a according to FIG. 5, in the case of the rope 1e shown in FIG. 9, only a single layer of wire strands 7e is provided, the wire strands 7e of the one layer are wound onto the fiber core 6e in a lay angle such that the torques generated by the fiber strands 3e, 3e of the fiber core 6e and by the wire strands 7e on loading of the rope 1e cancel each other out, so that the rope is rotation-resistant (and for example shows the rotational characteristic mentioned above for the rope 1a) or rotation-free, and the wire strands 7e, as described above, are preformed into a helical shape.

(25) FIG. 6 shows a further rope according to the invention 1b, the fiber strands of which are indicated in the drawing by hatching. It has a core rope 6b with a 1+6+12 structure. In order to influence a torque generated on loading of the rope 1b by the core rope 6b, the individual layers of the core rope 6b of fiber strands 60 are layer-stranded in opposite lay directions. A strand layer is arranged on the core strand 6b that has five strands 40 having a 1+5+(5+5)+10 structure, wherein only the outer layer of the strands 40 is composed of steel wires 42 and the inner 1+5+(5+5) structure is formed by fiber strands 41. The strands 40 are compacted as a whole, for example by hammering.

(26) An outer layer of outer strands 50 and 70 is wound around the strands 40. The outer strands 50 with fiber strands 51 and steel wires 52 have the same structure as the strands 40 and are also compacted, but have a smaller diameter. The outer strands 70 have a 1+6+(6+6)+12 structure. In the case of the outer strands 70 as well, a strand outer layer is formed by steel wires 72, and the strand interior, i.e. the 1+6+(6+6) structure, is composed of fiber strands 71. The outer strands 70 are also compacted.

(27) All of the fiber strands 60, 41, 51, 71 required for formation of the rope 1b are produced by means of the method described above and heated during stranding in order to form a one-piece fiber core. In production of the fiber strands 41, 51, 71, an amount of thermoplastic, such as PEEK, is provided such that during heating after stranding onto the respective fiber core, a sheath of the thermoplastic is formed in which the outer steel wires 42,52,72 are embedded. During their stranding into the rope 1b, the core strand 6b and the strands 40,50,70 are embedded in a matrix material 80 composed of thermoplastic. The matrix material 80 may be composed of the same plastic in which the fiber bundles of the fiber strands 60,41, 51, 71 are also embedded (such as PEEK) or composed of another plastic, such as polycarbonate, which adheres to the thermoplastic and optionally bonds chemically thereto.

(28) In the case of the robe 1b according to FIG. 6 as well, the fiber strands 60, the strands 40, and the outer strands 70 can be laid in such a manner that the rope 1b is rotation-resistant and for example has a rotational characteristic of one rotation of the rope <36/1000 d rope length on lifting of a load that is equivalent to 20% of F.sub.min.

(29) A rope 1c shown in FIG. 7 has a core rope 6c with a 1+6+(6+6)+12 structure. An outer layer of the core rope 6c is composed of steel wires 62c. The inner 1+6+6+(6+6) structure of the core rope 6c is formed by a fiber core, the fiber strands of which 60c produced by the method described above are parallel-stranded, and as described above, bonded to one another during stranding under heating.

(30) Strands 40c wound around the core rope 6c show a fiber core composed of a single fiber strand 41c and steel wires 42c stranded thereon (1+6 structure). An outer layer of the rope 1c is formed by steel wire strands 70c.

(31) In stranding of the rope 1c, the core strand 6c, the strands 40c and the outer strands 70c are embedded in a matrix material 80c of thermoplastic. The matrix material 80c is preferably composed of the same thermoplastic (for example polyamide) that was used for the production of the fiber strands 60c, 41c. The rope 1c has been compacted as a whole, for example by hammering.

(32) In the rope 1c, the steel wires 62c, fiber strands 60c, the strands 40c and the steel wire strands 70c can be laid in such a manner that the rope 1b is rotation-resistant, and for example with a rotational characteristic of one rotation of the rope <18/1000 d rope length on lifting of a load that is equivalent to 20% of F.sub.min.

(33) It is understood that the strands having wires of ropes 1a, 1b, 1c, 1d, 1e according to FIGS. 5 through 9 can also be preformed, as was discussed above for wire rope 1.