Endless winding cable with improved end fitting, system with such a cable, and method for producing a cable
Patent Information
- Application Number
- NL2039961
- Authority / Receiving Office
- NL · NL
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2025-03-12
- Publication Date
- 2026-09-21
- Estimated Expiration
- 2045-03-11
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Title: Endless winding cable with improved end fitting, system with such a cable, and method for producing a cable The invention relates to an endless winding cable according to the preamble of claim 1, as well as a system with such a cable, and a method for producing a cable. An endless winding cable of this type can be used in different types of industry, including but not limited to offshore, mining and heavy lifting and construction. In offshore, a cable of this type can be used as a mooring line for ships and structures like floating oil exploration or production facilities, or for a floating wind turbine. In particular, a cable of this type can be used as a so-called tendon or tether to anchor a (semi-submersible) floating object under tension to a bottom of a sea or ocean to form a tension leg platform (TLP) as a base for a wind turbine or other facility. In mining and heavy lifting such a cable may be used as a pendant for a crane. In construction such a cable may be used as a tension member in a bridge or suspension cable of a roof. The concept of endless winding cable, or rope, is explained on the page Rope of the English version of Wikipedia as follows: Endless winding rope is made by winding single strands of high- performance yarns around two end terminations until the desired break strength or stiffness has been reached. This type of rope (often specified as cable to make the difference between a braided or twined construction) has the advantage of having no construction stretch as is the case with above constructions. The two end terminations, also referred to as thimbles, are not only used as extreme ends during the winding process to form loops of yarn around them, but also remain in the cable as part of an end fitting at each end. Winding around thimbles which remain in the cable enables a very precise control over the length of each loop so as to avoid that some loops are shorter than others and thus would receive a higher load than longer loops when the cable is subject to a load. An endless winding cable is known from WO-2023 / 177286 (WO'286). This document discloses a cable which is produced by winding a main yarn around two thimbles which form two end fittings in the final cable. WO286 further discloses a cable with one thimble at one end and two thimbles at the other end of the cable. The two thimbles in one end fitting form a female end fitting, so that a connection with a further flexible cable can be established by putting a male end fitting with one thimble between the thimbles of the female end fitting, and inserting a connecting pin through the openings of the male and female end fittings. A disadvantage of the known cable is that a connecting pin with a large diameter is required for connecting the male and female end fittings, in particular in case of a cable with a relative high break load. This pin is relatively heavy compared to the weight of the cable, and it also requires the thimbles of both end fittings to be large as the openings in the thimbles need to receive the large diameter connecting pin. The invention aims to solve at least one of these problems, or at least to provide an alternative. In particular, the invention aims to provide a cable which enables a lighter connection to another cable or an other object. This aim is achieved by an endless winding cable according to claim 1, an endless winding cable according to claim 12, a system according to claim 15, and a method according to claim 16. Preferred embodiments are defined in the dependent claims. An endless winding cable comprises a first end fitting and a second end fitting, at least one yarn, and bundling means. The first end fitting comprises a first winding body with a first support surface and the second end fitting comprises a second winding body with a second support surface. The first winding body and the second winding body are provided at opposite ends of the cable. A length of the cable is defined by a distance from the first winding body to the second winding body along the cable. The at least one yarn extends from the first winding body to the second winding body, turns around the second winding body, extends from the second winding body to the first winding body, and turns around the first winding body, such that the yarn forms multiple turns around the first winding body and the second winding body. The first support surface holds a first stack of a plurality of layers of turns of the yarn, and the second support surface holds a second stack of a plurality of layers of turns of the yarn. The bundling means are arranged around the multiple turns of the yarn along a part of the cable extending between the first end fitting and the second end fitting such, that the multiple turns of the yarn form a compact bundle along said part of the cable. The first winding body has a first core with a first end portion and a second end portion. The first winding body is integrated such with the first core, that the first winding body and the first core contribute to a joint bending stiffness. The first end portion and the second end portion each protrude relative to the first support surface in opposite directions and are designed to connect the cable with the first end fitting to an other object. The joint bending stiffness of the first winding body with the integrated first core enables the first winding body to be smaller than a thimble of a prior art cable designed to withstand the same load. The dimensions of the prior art thimble are determined by the size of the connecting pin. This size is a result of the required bending stiffness to withstand a bending moment, which results from forces exerted on the ends of the connecting pin, which forces are counteracted by the thimble of the male end fitting on the middle of the connecting pin. The inventive integration of the first winding body with the first core results in the first winding body contributing to the bending stiffness of the core, so that they jointly absorb the bending moment. Therefore, the size of the first winding body is not determined by the minimum size of the opening in the thimble for receiving a large connecting pin, but merely by the resistance against bending of the first winding body itself. This results in a smaller first winding body. Also the first and second end portions of first core are smaller than the end portions of the prior art connecting pin. This enables smaller thimbles of the female end fitting that is to be connected to the male end fitting according to the invention too. In a test, a weight reduction of approximately 30% to 50% of the weight of the total connection has been achieved. In an embodiment, the first winding body and the first core are one piece of material. This ensures a seamless integration of the first winding body and the first core, and thus an optimized joint bending stiffness. In particular, the first winding body and the first core have been machined from one block of material. In particular, the machining comprises milling. Machining results in a precise shape of the first winding body. In an embodiment, the first core of the first winding body is a first pin comprising a middle section, the first end portion and the second end portion. The middle section of the first pin extends between the first end portion and the second end portion and has an outer circumferential shape. The first winding body comprises a through opening with an inner circumferential shape which corresponds such to the outer circumferential shape of the first pin, that the middle section of the first pin is embedded in the through opening of the first winding body. Embedding results in the engagement of the inner circumferential shape of the through opening with the pin over a length of the middle section. This ensures that the first winding body and the first core contribute to the joint bending stiffness. Making the first winding body and the first core separately results in a cheaper production process. In particular, the first winding body is a thimble. Such a thimble is a standard component for cables and thus relatively easy and cost effective to produce. In particular, the first pin is connected to the first winding body by means of interference fit, or location fit. These types of fit ensure a maximum contact between the first winding body and the first core and thus an optimum joint bending stiffness. In particular, the interference fit comprises shrink-fitting. Shrink-fitting reduces the amount of force which is required to insert the first pin in the through opening of the first winding body. In an embodiment, the inner circumferential shape of the through opening of the first winding body and the outer circumferential shape of the first pin are tapered. The tapered shape enables an easy insertion of the pin into the through opening at one hand, and a tight fit on the other hand, by applying an impulse on an end of the tapered pin after the insertion. In an embodiment, the outer circumferential shape of the first pin comprises screw thread and the inner circumferential shape of the through opening of the first winding body comprises matching screw thread. This enables the first winding body and the first core to be assembled by screwing, while the screw thread provides a helical contact line along the length of the middle section of the first pin which enables the joint bending stiffness. In an embodiment, the yarn comprises high modulus synthetic or natural fibres with Young's modulus of at least 55 GPa as determined by ASTM D7269. This results in a strong and relatively lightweight cable. In an embodiment, the yarn comprises load bearing fibres, which are chosen from a list consisting of aramid fibres, polyarylate fibre, Polybenzobisoxazole fibres, para-copolyamide yarns, and basalt fibres. In an embodiment, the second winding body has a second core with a third end portion and a fourth end portion, the second winding body is integrated such with the second core, that the second winding body and the second core contribute to a joint bending stiffness, and the third end portion and the fourth end portion of the second core each protrude relative to the second support surface in opposite directions and are designed to connect the cable with the second end fitting to an other object. As a result, the cable has two male end fittings, and is connectable at both ends to other cables or constructions with a female fitting. In particular, the second winding body and the second core are configured as above defined in relation to any of the embodiments of the first winding body and first core. In particular, the first and optional second core extend along an axis which runs substantially parallel to the relevant support surface, and / or substantially transverse to a plane defined by the turns of the yarn. The invention further relates to an endless winding cable comprising a first end fitting and a second end fitting, at least one yarn, and bundling means. The first end fitting comprises a first Winding body with a first support surface and the second end fitting comprises a second winding body with a second support surface. The first winding body and the second winding body are provided at opposite ends of the cable. A length of the cable is defined by a distance from the first Winding body to the second winding body along the cable. The at least one yarn extends from the first winding body to the second winding body, turns around the second winding body, extends from the second winding body to the first winding body, and turns around the first winding body, such that the yarn forms multiple turns around the first winding body and the second winding body. The first support surface holds a first stack of a plurality of layers of turns of the yarn, and the second support surface holds a second stack of a plurality of layers of turns of the yarn. The bundling means are arranged around the multiple turns of the yarn along a part of the cable extending between the first winding body and the second winding body such, that the multiple turns of the yarn form a compact bundle along said part of the cable. The second end fitting comprises a third winding body, and the at least one yarn also forms multiple turns around the first winding body and the third winding body. The third winding body holds a stack of a plurality of layers of turns of the yarn. The second end fitting comprises a yarn junction. The multiple turns of the yarn around the first winding body and the second winding body extend from the yarn junction to the second winding body, such as to form a flexible first leg, and the multiple turns of the yarn around the first winding body and the third winding body extend from the yarn junction to the third winding body, such as to form a flexible second leg. The flexible first leg and flexible second leg provide a movability of the second winding body and the third winding body away and towards each other, such that the second winding body and third winding body are connectable to respectively the first end portion and the second end portion of the first end fitting of another cable, as defined by any of the above described embodiments. Such a cable with a female end fitting with two flexible legs is specifically adapted to be connected to the other cable, which has a male end fitting comprising a winding body with an integrated core and a first end portion and a second end portion. As the core with the end portions is not removable during normal use of the cable, the flexible legs of the female end fitting enable the second winding body and the third winding body to be positioned beyond the end faces of the first end portion and the second portion and then to be connected to these end portions. The position of the yarn junction in relation to the second and third winding bodies depends on the dimensions of the winding body of the male end fitting of the other cable and on the flexibility of the first and second legs. Less flexible legs and / or a larger distance between the end faces of the first end portion and the second portion require longer legs and thus a position of the yarn junction further away from the second and third winding bodies. In general, the length of the flexible legs is less than 50%, in particular less than 25%, of the length of the cable away from the second and third winding bodies. In absolute terms, the length of the flexible legs is less then 5 meters, in particular less than 3 meters, and more than 0.25 meter, in particular more than 0.5 meter. In particular, the second winding body and the third winding body each have a connecting hole with an inner circumferential shape which corresponds to an outer circumferential shape of the first end portion, respectively the second end portion, of the core of the winding body of the other cable. While the shapes correspond, there is some play between the outer and inner circumferential shapes, so as to allow a pin and hole connection. In an embodiment, an endless winding cable comprises a first end fitting with an integrated core, as defined by any of the above described embodiments, and a second end fitting with a second and third winding body, a yarn junction, and flexible legs, as defined by any of the above described embodiments. This results in a cable with both an inventive male end fitting and an inventive female end fitting, which make them suitable for a system with a plurality of the same or similar cables. The invention further relates to such a system comprising at least a first endless winding cable and a second endless winding cable, as defined by any of the above described embodiments. The invention further relates to a method for producing an endless winding cable, comprising the following steps: providing a first winding body with a first support surface, providing a second winding body with a second support surface at a distance from the first winding body, which distance corresponds to a design length of the cable, providing at least one yarn and bundling means, winding the yarn from the first winding body to the second winding body, turning the yarn around the second winding body, winding from the second winding body to the first winding body, and turning around the first winding body, repeating the previous step such that the yarn forms multiple turns around the first winding body and the second winding body, the first support surface holds a first stack of a plurality of layers of turns of the yarn, the second support surface holds a second stack of a plurality of layers of turns of the yarn, until the number of turns of the yarn corresponds to a design thickness of the cable, and arranging the bundling means around the multiple turns of the yarn along a part of the cable extending between the first end fitting and the second end fitting such, that the multiple turns of the yarn form a compact bundle along said part of the cable. The first winding body has a first core with a first end portion and a second end portion. The first winding body is integrated such with the first core, that the first winding body and the first core contribute to a joint bending stiffness. The first end portion and the second end portion each protrude relative to the first support surface in opposite directions and are designed to connect the cable with the first end fitting to an other object. Producing according to this method results in a cable according to the invention. In particular, the first and second winding body, and an optional third winding body, are defined by any of the above described embodiments of the cable. Within the context of this document, a turn of a yarn may be either a semi-continuous loop, or a continuous loop. The term semi-continuous loop refers to the fact that the yarn has a finite length with distinct ends, while in a continuous loop a yarn has no ends. 50 in a semi-continuous loop, the at least one yarn is wound around the first and second winding body a plurality of times, forming a plurality of loops around these winding bodies , which is not completely continuous as the ends of the yarn are not connected to each other. The term integrated is to be interpreted by its common dictionary meaning: 'to make or be made into a whole'. Therefore, the claimed definition that the first winding body is integrated with the first core covers embodiments wherein the first winding body and the first core are made in one piece, and embodiments wherein the first winding body and the first core are separate parts which have been joined into a whole. The invention, its effects, and advantages will be explained in more detail on the basis of the schematic drawing, in which: Fig. 1 shows a cable according to the invention; Fig. 2 shows a perspective view of a device for making a cable according to the invention; Fig. 3 shows a top view of the cable of fig. 1; Fig. 4 shows section IV-IV from fig. 3; Fig. 5 end fittings of two separate cables according to the invention in a coupled state; Fig. 6 the end fittings of the cables of fig. 5, in a de-coupled state; Fig. 7 shows a side view VII-VII of the cables of fig. 5; Fig. 8 shows a perspective view of two separate cables according to the invention in a de- coupled state; Fig. 9 shows a perspective view of the cables of fig. 8 in a coupled state; Fig. 10 shows a sectional view of the end fittings of fig. 5; Fig. 11 shows a second embodiment of an end fitting according to the invention; Fig. 12 shows a third embodiment of an end fitting according to the invention; Fig. 13 shows a fourth embodiment of an end fitting according to the invention; Fig. 14 shows a fifth embodiment of an end fitting according to the invention. And Fig. 15 compares the moments of force of a connection between two cables with an end fitting according to the invention with the moments of force according to the prior art. The figures show an endless winding cable according to the invention, also referred to as cable within this specification, which is denoted in its entirety by reference number 1. Referring to figs 1-3, the cable 1 has a first end fitting 2, a second end fitting 4, and a plurality of yarns 6. The first end fitting 2 is also referred to as male end fitting and the second end fitting 4 is also referred to as female end fitting. The male and female end fittings are provided at opposite ends of the cable 1. Referring to fig. 10, the first end fitting 2 comprises a first winding body 10 with a first support surface 12 and a first core 14, in this embodiment a solid core. The first core 14 has a first end portion 16 and a second end portion 18, which protrude from the first winding body 10, relative to the first support surface 12, in opposite directions, and are designed to connect the cable 1 with the first end fitting 2 to an other object, such as another cable 1| with a female end fitting 4. The first winding body 10 is integrated such with the first core 14, that the first winding body 10 contributes to a bending stiffness of the first core 14. As a result, the total dimensions of the winding body 10 with the core 14 are smaller, than that of a thimble with a connecting pin of the prior art where the pin through the thimbles bears the bending moments by itself. In this embodiment, the first winding body 10 and the first core 14 have been machined from one block of material, in this case mainly by milling, resulting in one continuous piece of material without a seam between the first winding body 10 and the first core 14. The second end fitting 4 comprises a second and a third winding body, in this embodiment a second thimble 20 with a second support surface 22 and a third thimble 30 with a third support surface 32. The second thimble 20 and the third thimble 30 each have a connecting hole 24, 34 with an inner circumferential shape, in this case a cylindrical inner shape, which corresponds to an outer circumferential shape of the first end portion 16, respectively the second end portion 18, of the core 14 of the other cable 1. The first winding body 10, the core 14, and the thimbles 20, 30 of this embodiment are made of stainless steel. The cable 1 has a length L, measured from a centre of the first end fitting 2 to a centre of the second end fitting 4. The cable 1 is shown interrupted in figs. 1 and 3, to indicate that in reality the length L of the cable is longer than what is displayed, such as twenty meters, thirty meters, fifty meters, or more. The plurality of yarns 6 are in this embodiment ten yarns 6 which all extend from the first winding body 10 to the second thimble 20 or the third thimble 22, turn around the second or third thimble, extend from this second or third thimble to the first winding body 10, and turn around the first winding body 10. In this manner each of the plurality of yarns 6 forms a semi-continuous loop around the first winding body 10 and second thimble 20, or around the first winding body 10 and the third thimble 30. This loop is repeated a plurality of times, in this embodiment 950 times. So each of the yarns 6 makes 950 turns, resulting in a total of 9500 turns of yarns 6. A first layer of turns of the yarns 6 is supported directly on the first support surface 12, second support surface 22, and third support surface 32. Subsequent layers of the turns of the yarns 6 are supported indirectly by the first support surface 12, second support surface 22, and third support surface 32, via intermediate layers of the turns of the yarns 6. The layers of turns of the yarns 6 around the first winding body 10 form a first stack 13 of the plurality of layers of turns of the yarns 6 on the first support surface 12, the layers of turns of the yarns 6 around the second thimble 20 form a second stack 23 of the plurality of layers of turns of the yarns 6 on the second support surface 22, and the layers of turns of the yarns 6 around the third thimble 30 form a third stack 33 of the plurality of layers of turns of the yarns 6 on the third support surface 32. All ten yarns 6 of this embodiment form one loop, or alternatively a plurality of loops, around the first winding body 10 and second thimble 20, then one loop, or alternatively a plurality of loops, around the first winding body 10 and third thimble 20, followed again by a loop around the first winding body 10 and second thimble 20, etc. In an alternative embodiment, five yarns 6 form loops around the first winding body 10 and second thimble 20, and the other five yarns form loops around the first winding body 10 and third thimble 30. All turns of the yarn 6 extend parallel to each other over a major part of the length L of the cable 1. The turns extending to the second thimble 20 and the third thimble 30 diverge from a yarn junction 40, forming a flexible first leg 42 and a flexible second leg 44, respectively. The length of the flexible first leg 42 and the flexible second leg 44 of this embodiment is 1 meter. The yarn junction 40 forms the beginning of the second end fitting 4. A tape 50 circles helically around yarns 6 of the cable 1 from the first end fitting 2 to the second end fitting 4, and bundles all turns of the yarns 6 extending between the first end fitting 2 and the yarn junction 40 in one compact bundle 52 in a middle section 54 of the cable 1, as shown in figs. 2 and 3. As such, the tape 50 acts as bundling means around the main, parallel running, part of the yarn turns. In this embodiment, the tape 50 also separately bundles the turns of the yarns 6 of the first leg 42 and of the second leg 44 extending to both thimbles 20, 30 at the second end fitting 4. The flexible first leg 42 and the flexible second leg 44 have such a length and flexibility, that they provide a movability of the second thimble 20 and the third thimble 30 away and towards each other. This enables the second end fitting of a cable 1| to be connected to the first end fitting 2 of another cable 1, by first moving the second thimble 20 and the third thimble 30 away from each other, as shown in figs. 6 and 8, such that their mutual distance is greater than a length Lc of the core 14 of the first winding body 10 of the cable 1, as measured from an end face of the first end portion 16 to an end face of the second end portion 18. Secondly, the connecting hole 24 of the second thimble 20 is slid over the first end portion 16 and the connecting hole 34 of the third thimble 30 is slid over the second end portion 18 of the first end fitting 2 of the other cable 1. Thirdly, a securing pin 56 is inserted through a corresponding pin hole 58 in the first end portion 16 and the second end portion 18 of the first end fitting 2 to prevent the second thimble 20 and the third thimble 30 sliding from the first end portion 16 and the second end portion 18 when the cable 1 is slack. This connected state of the two cables 1 and 1' is shown in figs. 5, 9, and 10 The yarns 6 consist of fibres, in this embodiment aramid fibres with a density of 3220 dTex. These yarns are sold under the name Twaron® by Teijin Aramid. Aramid fibres have a Youngs modulus of at least 55 GPa as determined by ASTM D7269. A cable cover (not shown in the figures) is provided around the tape 50 and first end fitting 2 and the second end fitting 4 to protect the yarns and components of the first end fitting 2 and the second end fitting 4 against external influences and impacts. A device 90 which is suitable for a method for producing a cable according to the invention is shown in figure 4. The device 90 is designed to produce an endless winding cable, such as cable 1 as described above, or a cable according to one of the following embodiments, by winding at least one yarn, in this embodiment ten yarns simultaneously, around two or three winding bodies that are provided at opposite ends of the cable. The device 90 comprises an elongated guide 92, a carriage 93, a yarn feeder 94, a first winding body holder 95, and a second winding body holder 96. The first and second winding body holder 95, 96 are designed for each holding one winding body with protruding end portions. The second winding body holder 96 is also designed to hold two thimbles on top of each other such, that the yarns are wound around both thimbles in the second winding body holder 96 either simultaneously, or alternating. In this embodiment the elongated guide 92 comprises two elongated I-profiles 97. The elongated guide 92 is suspended from a ceiling of a production facility via supports (not shown) at an interval of approximately 2 meters. Further details of the device 90 are disclosed in WO-2017 / 099589, wherein it is referred to as device 100, which disclosure is incorporated herein by reference. A second embodiment of a cable 101 is shown in fig. 11. The same and similar elements as described in relation to cable 1 are denoted with the same reference number, increased with 100. Below the main differences with the first embodiment are described, while for the other elements reference is made to the description of the first embodiment. The cable 101 comprises a first end fitting 102, a second end fitting 104, and a plurality of yarns 106. The first end fitting 102 comprises a first winding body 110 with a first support surface 112 and a first core 114, in this embodiment a solid pin. The solid pin 114 has a first end portion 116 and a second end portion 118, which protrude from the first winding body 110, relative to the first support surface 112, in opposite directions. The first end portion 116 and the second end portion 118 are designed to connect the cable 101 with the first end fitting 102 to an other object, such as another cable 101' with a female end fitting 104. The female end fitting 104 is comparable to the female end fitting 4 of the first embodiment. The female end fitting 104 thus comprises flexible legs made of the plurality of yarns 106, as well as a second thimble 120 with a second support surface 122 and a third thimble 130 with a third support surface 132. The cable 101 is made by endless winding the plurality of yarns 106 around the first winding body 110 of the first end fitting 102 and the second thimble 120 and third thimble 130 of the second end fitting 104, as described above in more detail. In this embodiment, the first winding body 110 and the solid pin 114 have been assembled from two separate elements by means of interference fit, in particular by shrink fitting. The first winding body 110 is provided with a cylindrical through opening 160, e.g. by means of drilling. The shape of the first winding body 110 corresponds to that of a thimble of a cable according to the prior art. The outer circumference of the solid pin 114 is slightly larger than the inner circumference of the through opening 160. The first winding 110 is heated such, that the inner circumference of the through opening 160 becomes larger, the solid pin 114 is inserted, and the first winding body shrinks by cooling. This results in the solid pin 114 being embedded in the through opening 160 and the first winding body 110 is integrated such with the solid pin 114, that the first winding body 110 contributes to a bending stiffness of the solid pin 114. As a result, the total dimensions of the winding body 110 with the pin 114 are smaller, than that of a thimble with a connecting pin of the prior art which is designed for the same load, where the pin through the thimbles bears the bending moments by itself. The female end fitting 104 is connectable to a male end fitting 102, in a manner comparable to the first embodiment. The flexible legs leg of the end fitting 104 thus enable the second thimble 120 and the third thimble 130 to move away and towards each other for the second end fitting 104 of a cable 101' to be connected to the first end fitting 102 of another cable 101, as described in more detail with reference to the first embodiment. A securing pin 156 is inserted through corresponding pin holes in the first end portion 116 and the second end portion 118 of the first end fitting 102. A third embodiment of a cable 201 is shown in fig. 12. The same and similar elements as described in relation to cable 1 are denoted with the same reference number, increased by 200. Below the main differences with the first embodiment are described, while for the other elements reference is made to the description of the first embodiment. The cable 201 comprises a first end fitting 202, a second end fitting 204, and a plurality of yarns 206. The first end fitting 202 comprises a first winding body 210 with a first support surface 212 and a first core 214, in this embodiment a solid pin. The solid pin 214 has a first end portion 216 and a second end portion 218, which protrude from the first winding body 210, relative to the first support surface 212, in opposite directions. The first end portion 216 and the second end portion 218 are designed to connect the cable 201 with the first end fitting 202 to an other object, such as another cable 201' with a female end fitting 204. The female end fitting 204 is comparable to the female end fitting 4 of the first embodiment. The female end fitting 204 thus comprises flexible legs made of the plurality of yarns 206, as well as a second thimble 220 with a second support surface 222 and a third thimble 230 with a third support surface 232. The cable 201 is made by endless winding the plurality of yarns 206 around the first winding body 210 of the first end fitting 202 and the second thimble 220 and third thimble 230 of the second end fitting 204, as described above in more detail. In this embodiment, the first winding body 210 and the solid pin 214 have been assembled from two separate elements. The first winding body 210 is provided with a tapered through opening 260, e.g. by means of milling. The shape of the first winding body 210 corresponds to that of a thimble of a cable according to the prior art, except for the tapered shape of the through opening 260. The outer circumference of a middle section of the solid pin 214 corresponds to the inner circumference of the through opening 260 and is thus tapered as well. The solid pin 214 is connected to the first winding body 210 by inserting it into the through opening 260, followed by an impulse on the solid pin 214, e.g. by hitting it with a hammer. This results in the solid pin 214 being embedded in the through opening 260 and the first winding body 210 being integrated such with the solid pin 214, that the first winding body 210 contributes to a bending stiffness of the solid pin 214. As a result, the total dimensions of the winding body 210 with the pin 214 are smaller, than that of a thimble with a connecting pin of the prior art which is designed for the same load, where the pin through the thimbles bears the bending moments by itself. The second end fitting 204 is a female end fitting, comparable to the female end fitting 4 of the first embodiment. The flexible legs leg of the end fitting 204 thus enable the second thimble 220 and the third thimble 230 to move away and towards each other for the second end fitting 204 of a cable 201| to be connected to the first end fitting 202 of another cable 201, as described in more detail with reference to the first embodiment. A securing pin 256 is inserted through corresponding pin holes in the first end portion 216 and the second end portion 218 of the first end fitting 202. A fourth embodiment of a cable 301 is shown in fig. 13. The same and similar elements as described in relation to cable 1 are denoted with the same reference number, increased by 300. Below the main differences with the first embodiment are described, while for the other elements reference is made to the description of the first embodiment. The cable 301 comprises a first end fitting 302, a second end fitting 304, and a plurality of yarns 306. The first end fitting 302 comprises a first winding body 310 with a first support surface 312 and a first core 314, in this embodiment a solid pin. The solid pin 314 has a first end portion 316 and a second end portion 318, which protrude from the first winding body 310, relative to the first support surface 312, in opposite directions. The first end portion 316 and the second end portion 318 are designed to connect the cable 301 with the first end fitting 302 to an other object, such as another cable 301' with a female end fitting 304. The female end fitting 304 is comparable to the female end fitting 4 of the first embodiment. The female end fitting 304 thus comprises flexible legs made of the plurality of yarns 306, as well as a second thimble 320 with a second support surface 322 and a third thimble 330 with a third support surface 332. The cable 301 is made by endless winding the plurality of yarns 306 around the first winding body 310 of the first end fitting 302 and the second thimble 320 and third thimble 330 of the second end fitting 304, as described above in more detail. In this embodiment, the first winding body 310 and the solid pin 314 have been assembled from two separate elements. The first winding body 310 is provided with a cylindrical through opening 360, e.g. by means of drilling. The cylindrical through opening is provided with screw thread. The shape of the first winding body 310 corresponds to that of a thimble of a cable according to the prior art, except for the threads in the through opening 360. A middle section of the solid pin 314 is provided with matching screw thread. The outer circumference of the middle section of the solid pin 314 corresponds to the inner circumference of the through opening 360. The solid pin 314 is connected to the first winding body 310 by screwing it into the through opening 360. While there is some play in the screw thread connection, there is contact in the radial direction between the solid pin 314 and the first winding body 310 over the full length of the middle section of the solid pin 314. This results in the solid pin 314 being embedded in the through opening 360 and the first winding body 310 being integrated such with the solid pin 314, that the first winding body 310 contributes to a bending stiffness of the solid pin 314. As a result, the total dimensions of the winding body 310 with the pin 314 are smaller, than that of a thimble with a connecting pin of the prior art which is designed for the same load, where the pin through the thimbles bears the bending moments by itself. The second end fitting 304 is a female end fitting, comparable to the female end fitting 4 of the first embodiment. The flexible legs leg of the end fitting 304 thus enable the second thimble 320 and the third thimble 330 to move away and towards each other for the second end fitting 304 of a cable 301| to be connected to the first end fitting 302 of another cable 301, as described in more detail with reference to the first embodiment. A securing pin 356 is inserted through corresponding pin holes in the first end portion 316 and the second end portion 318 of the first end fitting 302. A fifth embodiment of a cable 401 is shown in fig. 14. The same and similar elements as described in relation to cable 1 are denoted with the same reference number, increased by 400. Below the main differences with the first embodiment are described, while for the other elements reference is made to the description of the first embodiment. The cable 401 comprises a first end fitting 402, a second end fitting 404, and a plurality of yarns 406. The first end fitting 402 comprises a first winding body 410 with a first support surface 412 and a first core 414, in this embodiment a solid pin. The solid pin 414 has a first end portion 416 and a second end portion 418, which protrude from the first winding body 410, relative to the first support surface 412, in opposite directions. The first end portion 416 and the second end portion 418 are designed to connect the cable 401 with the first end fitting 402 to an other object, such as another cable 401' with a female end fitting 404. The female end fitting 404 is comparable to the female end fitting 4 of the first embodiment. The female end fitting 404 thus comprises flexible legs made of the plurality of yarns 406, as well as a second thimble 420 with a second support surface 422 and a third thimble 430 with a third support surface 432. The cable 401 is made by endless winding the plurality of yarns 406 around the first winding body 410 of the first end fitting 402 and the second thimble 420 and third thimble 430 of the second end fitting 404, as described above in more detail. In this embodiment, the first winding body 410 and the solid pin 414 have been assembled from two separate elements. The first winding body 410 is provided with a cylindrical through opening 460, e.g. by means of drilling. The shape of the first winding body 410 corresponds to that of a thimble of a cable according to the prior art. The outer circumference of a middle section of the solid pin 414 corresponds to the inner circumference of the through opening 460. The solid pin 414 is connected to the first winding body 410 by welding it in the through opening 460. While the figure shows two annular welds 462at a plane where the first end portion 416 and the second end portion 418 extend form the first winding body 410, a cylindrical weld along a greater part of, or the whole, middle section of the solid pin 414 is preferred, e.g. by means of friction welding. There is contact in the radial direction between the solid pin 414 and the first winding body 410 over substantially the full length of the middle section of the solid pin 414. This results in the solid pin 414 being embedded in the through opening 460 and the first winding body 410 being integrated such with the solid pin 414, that the first winding body 410 contributes to a bending stiffness of the solid pin 414. As a result, the total dimensions of the winding body 410 with the pin 414 are smaller, than that of a thimble with a connecting pin of the prior art which is designed for the same load, where the pin through the thimbles bears the bending moments by itself. The second end fitting 404 is a female end fitting, comparable to the female end fitting 4 of the first embodiment. The flexible legs leg of the end fitting 404 thus enable the second thimble 420 and the third thimble 430 to move away and towards each other for the second end fitting 404 of a cable 401' to be connected to the first end fitting 402 of another cable 401, as described in more detail with reference to the first embodiment. A securing pin 456 is inserted through corresponding pin holes in the first end portion 416 and the second end portion 418 of the first end fitting 402. Two or more cables of the above described embodiments form a system according to the invention. In an embodiment of the system, the cables are according to one and the same embodiment. In another embodiment of a system, some of the cables are according to different embodiments than other cables in the system. In an even further embodiment of a system, the system comprises cables with two male end fittings and cables with two female end fittings. This enables a chain of cables with alternatingly a cable with two male end fittings and a cable with two female end fittings. Several variants are possible within the scope of the attached claims. The features of the above described preferred embodiment(s) may be replaced by any other feature within the scope of the attached claims, such as the features described in other embodiments, and in the following paragraphs. An endless winding cable according to the invention may be made of more or less than ten yarns, such as one yarn, two yarns, or at least five yarns. Preferably, a cable is made of a plurality of yarns. In particular a cable is made of at least twelve yarns, or of twenty-four yarns. The total number of yarn turns, i.e. yarn turns per layer and number of layers, depends on the required strength of the cable, and the strength of one individual yarn, as well as the required safety margin. The number of layers depends on the required number of yarn turns, and the available width in the relevant winding body resulting in a maximum number of yarn turns in the width direction. In particular, each yarn makes at least a thousand turns, more in particular more than five thousand turns. The winding body and the core contribute to a joint bending stiffness and thus jointly define a bending stiffness of the winding body including the core. In an embodiment, a combination of the ways of embedding a pin in a through opening of a winding body is made, in particular a cylindrical pin is connected by means of interference fit, in particular shrink fit, and screw thread, of interference fit and welding, or of screw thread and welding, or a tapered pin is welded to a winding body after inserting it into a tapered through opening. In an embodiment, a cable comprises an end fitting with integrated pin at each end of the cable. In another embodiment, a cable comprises an end fitting with integrated pin at one end of the cable, and an end fitting with a winding body without an integrated pin at the other end of the cable, such as a thimble. In an embodiment, a first core of a first end fitting comprises a first and a second pin. The first pin comprises a first end portion and the second pin comprises the second end portion. Preferably, the first and second pin abut each other within the through opening of the relevant winding body. In an embodiment, the core of the relevant winding body is solid. In an alternative embodiment, the core of the relevant winding body comprises cavities. While the shape of the winding bodies, pins, end portions of the pins, and thimbles, as well as the associated through openings and connecting holes of most of the above described embodiments is cylindrical, further embodiments comprise different shapes, such as, but not excluding, polygonal shapes and oval shapes. The shape of the first, second, and optional third and further support surfaces is curved, as seen in a cross section perpendicular to a centre axis of the winding body, so as to provide a smooth entry of the yarn turns to the support surface, as well as a gradual change in the pressure force exerted by the support surface on the yarn turns. In particular, the support surface is part cylindrical. The shape of the first, second, and optional third and further support surfaces is an isosceles trapezium, as seen in a cross section a plane defined by a length direction of the cable and the centre axis of the winding body. Patent NL-2033719 by the same applicant discloses different support surfaces, which are incorporated herein by reference. In an embodiment, a yarn used for the invention consists of plastic fibres, in particular thermoplastic fibres, such as polyamide fibres, particularly nylon fibres, polyester fibres, polypropylene fibres, polyethylene fibres, HMPE fibres, LCAP fibres, or PBO fibres. In an embodiment, the cable comprises other types of yarns, e.g., yarns made of carbon fibres, a metal, or a natural fibre, such as basalt fibres. Yarns of fibres may consist for 100% of the relevant fibre type, but could also comprise a small portion of an auxiliary material, e.g., a coating on the fibres to protect the fibres against wear and / or environmental influences. As such auxiliary material is only a small portion in weight, and does not contribute to the strength of the cable, the phrase yarn consisting of fibres is considered to include embodiments with such auxiliary materials within the context of this document. In particular, a yarn consists of any of the following fibre types: PBO (Polybenzobisoxazole; sold under the name Zylon by TOYOBO CO., LTD), polyarylate fibres (sold under the name Vectran by Kuraray Co., Ltd), para-aramid yarns sold under the name Twaron (registered trademark of Teijin Aramid B.V.) and under the name Kevlar (registered trademark of E.|. du Pont de Nemours and Company) with a density of 1610 dtex, 4830 dtex, 6440 dtex, 16100 dtex, or 17000 dtex, as well as higher, lower, and intermediate densities and with or without a coating, para-copolyamide yarns, sold under the name Technora (registered trademark of Teijin Aramid B.V.), as well as yarns made of fibres with similar properties. Examples of para-armid yarns are Twaron 1000 with a Young's modulus of 65 GPa and Twaron 3200 with a Youngs modulus of 138 GPa. In particular, a yarn made of basalt fibres is suitable for an endless winding cable according to the invention. An example is a 24.000 dtex basalt yarn. In an embodiment, the winding body is made of a plastic material instead of a metal, or of a different metal than stainless steel, including but not limited to different steel alloys, aluminium alloys, magnesium alloys, and titanium. In an embodiment, the bundling means comprises a tube which is heat shrunken to the multiple turns of the yarn. It is noted that British spelling is applied in the above specification for terms such as fibre, mould, and centre. These terms can be replaced for the relevant US type of spelling, fiber, mold', and center' without changing the content of this specification.
Claims
1. Endless winding cable (1), comprising a first end fitting (2) and a second end fitting (4), at least one yarn (6), and bundling agents (50), where the first end fitting (2) comprises a first winding body (10) with a first support surface (12) and the second end fitting (4) includes a second winding body (20) with a second support surface (22), the first winding body (10) and the second winding body (20) opposite where the ends of the cable (1) are located, a length (L) of the cable is defined by a distance from the first winding body (10) to the second winding body (20) along the cable, the at least one thread (6) extends from the first winding body (10) to the second winding body (20), wraps around the second winding body (20), extends from the second winding body (20) to the first winding body (10) and rotates around the first winding body (10), such that the yarn (6) forms multiple windings around the first winding body (10) and the second winding body (20), the first support surface (12) a first stack (13) of a number of layers of windings of the yarn (6) holds, the second support surface (22) a second stack (23) of a number of layers of windings likes the yarn (6), the bundling agents (50) around the multiple windings of the yarn (6) are applied along a part (54) of the cable that extends between the first end fitting (2) and the second end fitting (4), such that the multiple windings of the yarn (6) form a compact bundle (52) along the said part of the cable, with the characteristic that the first winding body (10) has a first core (14) with a first end section (16) and a second part of the final section (18), the first winding body (10) is integrated with the first core (14) in such a way that the first The wrapping body (10) and the first core (14) contribute to a combined bending stiffness, and the first end section (16) and the second end section (18) each in opposite directions protrude from the first support surface (12) and be designed to connect the cable (1) with the first to connect end fitting (2) to another object (1').
2. Endless coiled cable (1) according to claim 1, where the first coiled body (10) and the first core (14) consist of a single piece of material.
3. Endless coiled cable (1) according to claim 2, where the first coiled body (10) and the first core (14) machined from a single block of material.
4. Endless coiled cable (101) according to claim 1, where the first core of the first winding body (110) a first pin (114) is, comprising a middle section, the first end section (116) and the second end section (118), where the middle section of the first pen (114) extends between the first end section (116) and the second end section (118) and a has an outer perimeter shape, and the first winding body (110) includes a through opening (160) with an inner outline shape that corresponds to the outer outline shape of the first pin (114), that the middle section of the first pin (114) is embedded in the through opening (160) of the first winding body (10).
5. Endless coiled cable (101) according to claim 4, where the first pin (114) is connected to the first winding body (110) by means of a press fit or a location fit.
6. Endless coiled cable (101) according to conclusion 5, where the crimp fit is a crimp connection includes.
7. Endless coiled cable (201) according to one or more of claims 4-6, where the inner perimeter shape of the feed-through opening (260) of the first winding body (210) and the the outer outline of the first pin (214) should be conical.
8. Endless coiled cable (301) according to one or more of claims 4-7, where the outer outline shape of the first pin (314) includes thread and the inner outline shape of the the feed-through opening (360) of the first winding body (310) includes corresponding threading.
9. Endless winding cable (1) according to one or more of the preceding claims, where the yarn (6) synthetic or natural fibers with a high modulus comprising with an elastic modulus of ten at least 55 GPa as determined by ASTM D7269.
10. Endless winding cable (1) according to one or more of the preceding claims, where the yarn (6) includes load-bearing fibers, which are selected from a list consisting of aramid fibers, polyarylate fibers, polybenzobisoxazole fibers, para-copolyamide yarns and basalt fibers.
11. Endless coiled cable (1) according to one or more of the preceding claims, where the second winding body has a second core with a third end section and a fourth end section, the second winding body is integrated with the second core in such a way that the second winding body and the second core contribute to a combined bending stiffness, and the third end section and the fourth end section of the second core each protruding in opposite directions relative to the second support surface and designed to connect the cable (1) with the second end fitting (4) to another to connect object (1').
12. Endless winding cable (1') comprising a first end fitting (2) and a second end fitting (4), at least one yarn (6), and bundling agents (50), where the first end fitting (2) comprises a first winding body (10) with a first support surface (12) and the second end fitting (4) includes a second winding body (20) with a second support surface (22), the first winding body (10) and the second winding body (20) opposite where the ends of the cable (1|) are located, a length (L) of the cable is determined by a distance of from the first winding body (10) to the second winding body (20) along the cable, the at least one thread (6) extends from the first winding body (10) to the second winding body (20), wraps around the second winding body (20), extends from the second winding body (20) to the first winding body (10) and rotates around the first winding body (10), such that the yarn (6) forms multiple windings around the first winding body (10) and the second winding body (20), the first support surface (12) a first stack (13) of a number of layers of windings of the yarn (6) holds, the second support surface (22) a second stack (23) of a number of layers of windings likes the yarn (6), the bundling agents (50) are arranged around the multiple windings of the yarn (6) in such a way along a section (54) of the cable that extends between the first winding body and the second winding body (20), so that the multiple windings of the yarn (6) form a compact bundle (52) along the said part of the cable (1), with the characteristic that the second end fitting (4) includes a third winding body (30), where the yarn (6) also multiple forms windings around the first winding body (10) and the third winding body (30), where the third winding body (30) holds a stack (33) of multiple layers of windings of the yarn (6), the second end fitting (4) includes a thread branch (40), the multiple windings of the yarn (6) around the first winding body (10) and the second winding body (20) extend from the yarn branch to the second winding body (20), such that that a flexible first leg (42) is formed, the multiple windings of the yarn (6) around the first winding body (10) and the third winding body (30) extend from the yarn branch (40) to the third winding body (30), such that that a flexible second leg (44) is formed, and the flexible first leg (42) and the flexible second leg (44) ensure that the second winding body (20) and the third winding body (30) can move from and to each other, such that that the second winding body (20) and the third winding body (30) can be connected to respectively the first end section (16) and the second end section (18) of the first end fitting (2) of a other cable (1), as defined in one or more of the preceding claims.
13. Endless coiled cable (1') according to claim 12, where the second coiled body (20) and the third winding body (30) each have a connecting hole (24, 34) with an inner circumference shape that corresponds to an outer outline shape of the first end section (16), respectively the second end section (18), of the core of the other cable (1).
14. Endless coiled cable (1) according to one or more of claims 1-10, where the second end fitting (4) includes a third winding body (30) and a yarn branch (40), as characterized by one or more of the conclusions 12-13.
15. System consisting of at least one first endless winding cable (1) and one second endless winding cable (1') includes, where the first endless winding cable (1) is defined by one or more of the claims 1-11, or 14, and the second endless winding cable (1') is defined by one or more of conclusions 12-14.
16. Method for producing an endless winding cable (1), comprising the following steps: providing a first winding body (10) with a first support surface (12), providing a second winding body (20) with a second support surface (22) at a distance of the first winding body (10), which distance corresponds to a design length of the cable, providing at least one yarn (6) and bundling materials (50), winding the yarn (6) from the first winding body (10) to the second winding body (20), wrapping the yarn (6) around the second winding body (20), wrapping the second winding body (20) to the first winding body (10), and turn around the first winding body (10), repeat the previous step so that the yarn (6) forms multiple windings around the first wrapping body (10) and the second wrapping body (20), the first support surface (12) a first stack (13) of a number of layers of windings of the yarn (6) holds, the second support surface (22) a second stack (23) of a number of layers of windings of the yarn (6) holds, until the number of windings of the yarn (6) corresponds to a design thickness of the cable, and place the bundling agents (50) around the multiple windings of the yarn (6) along a part of the cable that extends between the first end fitting (2) and the second end fitting (4), that the multiple windings of the yarn (Do) not form a compact bundle along the said part of the cable, with the characteristic that the first winding body (10) has a first core with a first end section (16) and a second end section (18), the first winding body (10) is integrated with the first core in such a way that the first winding body (10) and the first core contribute to a combined bending stiffness, and the first end section (16) and the second end section (18) each in opposite directions protrude from the first support surface (12) and be designed to connect the cable with the first to connect end fitting (2) to another object.