Hybrid strand for technical ropes and manufacturing method thereof

Abstract

The present invention relates to a hybrid strand obtained by a hybridisation concept or system based on covering a primary strand having particular mechanical properties with a covering strand that has different, or at least partially different, mechanical properties from those of the primary strand, wherein said covering strand is arranged by overfeeding, wrapping it around the primary strand. The hybrid strand is intended for use in technical ropes, both for the construction of the core and, in particular, for the construction of the sheath, thus obtaining small-diameter technical ropes that can be approved according to the European standard applicable in each case.

Description

[0001] HYBRID ROPE FOR TECHNICAL ROPES AND MANUFACTURING METHOD

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The invention relates to a rope and the method for manufacturing said rope, where said rope is framed within the technical ropework for the vertical world, being conceived to be used, among others, in Personal Protective Equipment (PPE) for the prevention of falls from height.

[0004] In particular, the invention relates to the arrangement of the strands that make up both the core and the sheath that covers said core and that form said rope, where the strands have a hybrid construction from the braiding of primary strands or fibers of different mechanical properties, forming a hybrid braided strand that can be used, in the shaping of the rope, to form the sheath, the core, or both.

[0005] STATE OF THE ART

[0006] In the field of work at height, the use of ropes is commonplace to protect workers from accidental falls. Therefore, one can find rope lanyards, anchor lines for sliding fall arrest devices, anchor devices, and ropes used for rope access work, known as vertical work.

[0007] The ropes used in this type of work at height are made from fiber material and have a core and sheath construction, where the core is twisted, while the sheath is braided and covers and protects the core of the rope, this type of construction being called "Kernmantle".

[0008] “Kernmantle” type construction ropes have been designed to be used, among other things, in Personal Protective Equipment (PPE) for the prevention of falls from height including semi-static ropes (according to UNE-EN-1891 standards), dynamic ropes (according to UNE-EN 892) and auxiliary ropes (according to UNE-EN-564).

[0009] With regard to semi-static ropes, their primary use is for rope access work, where they are used as lanyards, anchor lines for sliding fall arrest devices, rope-based anchor devices, and ropes for accessing difficult terrain. Other common uses include situations similar to rope access work, but in the context of caving and canyoning.

[0010] Dynamic ropes, when used as part of a safety chain, are capable of arresting a person's free fall. Their maximum impact force is limited, and they are primarily used in mountaineering or climbing.

[0011] With regard to auxiliary ropes, these are intended to withstand forces, contributing to protection against falls from a height, but not to the absorption of energy produced by said fall.

[0012] Regarding dynamic and semi-static ropes, polyamide is one of the most commonly used materials for their manufacture. However, polyamide presents a limitation in the execution of rapid maneuvers, which are performed with high friction, producing defects such as localized crystallization due to the high temperatures generated in the access rope, as well as tears in the sheath due to rubbing and friction with natural elements.

[0013] Therefore, with the aim of improving the performance of these types of ropes under friction, the field of technology has evolved, presenting alternatives made from other materials accepted under the applicable standards. These proposals, besides increasing the cost of the product and making it economically inaccessible, present difficulties in the construction of semi-static ropes, leading the technology in two directions.

[0014] The first of these approaches has focused on the production of thicker ropes, which runs counter to market demands. Although the current market requires ropes with a smaller diameter, these ropes must be able to absorb enough energy to meet the requirements of European standards regarding rope dynamic properties—that is, energy absorption during a fall—for semi-static ropes (according to UNE-EN-1891), dynamic ropes (UNE-EN 892), and auxiliary ropes (UNE-EN-564). The low elongation coefficient of the alternative fibers permitted by the standards prevents this energy absorption, so the polyamide core will function independently of the sheath. Accepting this condition will require increasing the rope's diameter, as the core will need to be thicker to withstand the impact of a fall on its own.This first aspect generates ropes that, although thick, are compliant with European standards, consisting of a polyamide core that tolerates energy absorption in the event of falls and a sheath of alternative material permitted by the standard that provides friction resistance properties, thus both structures working separately.

[0015] The second trend has been towards the formation of thin ropes, that is, of low diameter, compared to the previous ones, but which do not comply with European regulations, offering zero guarantees to the user who, based on their own criteria, decides to try these new materials, or who comply with more lax regulations or regulations of other countries.

[0016] Therefore, the need becomes evident to develop and provide technical ropes whose construction allows for low diameters, while at the same time allowing these ropes to be certified or approved according to the applicable regulations, for example, UNE EN 1891 for semi-static ropes, UNE-EN 892 for dynamic ropes and UNE-EN-564 for auxiliary ropes.

[0017] DESCRIPTION

[0018] To address the identified needs, the present invention provides a hybridized rope, a rope using this hybridized rope, and a method for constructing a rope with hybridized ropes, as disclosed in the independent claims. Preferred embodiments are set forth in the dependent claims of each of these independent claims.

[0019] The invention being advocated is related to “kernmantle” type construction ropes, therefore, within the context of the invention, a sheath is defined as a set of braided ropes that protect the core, for example, against external abrasion and degradation due to ultraviolet radiation.

[0020] Likewise, within the context of the invention, a core is defined as a main resistant element of technical ropes made up of parallel elements gathered and twisted together in one or more replicas or forming braids.

[0021] On the other hand, within the context of the invention, a rope is defined as a plurality of twisted threads or fibers. Following this definition of rope, and as will be described later, a “hybrid rope,” within the context of the invention, is defined as a rope that is coated by overfeeding a second thread / fiber or second rope.

[0022] According to the foregoing, the present invention provides, firstly, a hybridized rope comprising a primary rope, this primary rope being twisted a number of turns per meter, wherein said primary rope is covered by overfeeding a covering rope arranged by wrapping around the primary rope in the same twist direction as the latter.

[0023] The concept of hybridization, which can be called a hybridization system for obtaining hybridized ropes, is based on the coating of the primary rope, which has particular mechanical properties, with a coating rope with different, or at least partially different, mechanical properties to those of the primary rope.

[0024] For example, the primary rope has the greatest elongation capacity or percentage, which largely depends on the type of material from which it is made, while the coating rope exhibits greater abrasion resistance than the primary rope. Therefore, the hybrid rope obtained through this hybridization system exhibits composite mechanical properties such as, for example, a high elongation capacity and, at the same time, high abrasion resistance.

[0025] Accordingly, the primary rope is preferably made of a first material and the covering rope is made of a second material, these materials preferably being different from each other, each exhibiting different mechanical properties. For example, the primary rope may be made of polyamide, while the covering rope is made of aramid.

[0026] Alternatively, the primary rope comprises a primary yarn twisted upon itself a number of turns per meter, the primary yarn being made from the first material.

[0027] Alternatively, the primary strand comprises a plurality of primary yarns arranged parallel to each other and twisted together a certain number of turns per meter, where each primary yarn within the plurality of base yarns is made from the first material. The first material may be selected from polyethylene, polypropylene, thermoplastic polyurethane, high-density polyethylene (HDPE), polyoxymethylene (POM or acetal), polyethylene terephthalate, polybutylene terephthalate (PBT), or acrylonitrile butadiene styrene (ABS).

[0028] Alternatively, the covering strand comprises a plurality of covering threads twisted together a number of turns per meter, where each covering thread within the plurality of covering threads is made from the second material.

[0029] Preferably, the covering strand comprises an untwisted covering yarn, wherein the covering yarn is made of the second material.

[0030] The second material can be selected from Aramid, Ultra High Molecular Weight Polyethylene (UHMWPE), Carbon Fiber, Glass Fiber, PBO (Polyphenylene Benzobisoxazole), Basalt Fiber, Polyparaphenylene Terephthalamide (PPTA), Vectran, Polyacrylonitrile Fiber (PAN).

[0031] According to the above, this hybridization system of the ropes allows obtaining technical construction ropes of the “Kernmantle” type that are capable of passing the mechanical and dynamic tests provided for in European regulations, to be approved according to the regulations applicable in each case, while maintaining a reduced diameter, for example, between 4 and 10mm.

[0032] In one embodiment, the invention provides a rope comprising an elongated core covered, or at least partially covered, by a sheath, where the sheath comprises a plurality of hybrid strands braided together. Therefore, in this embodiment, the rope sheath could be referred to as a hybrid sheath, since said sheath comprises a plurality of braided hybrid strands.

[0033] Alternatively, within the plurality of hybrid ropes that make up the sheath, at least in a first hybrid rope, the primary rope is twisted clockwise, and, while in at least a second hybrid rope, the primary rope is twisted counterclockwise.

[0034] Alternatively, the core is a rope comprising a plurality of base yarns twisted together a number of turns per meter, where each base yarn within the plurality of base yarns is made from a third material. In yet another alternative, the core comprises a plurality of ropes twisted together a number of turns.

[0035] The third material can be selected from Polyethylene, Polypropylene, Thermoplastic Polyurethane, High Density Polyethylene (HDPE), Polyoxymethylene (POM or Acetal), Polyethylene Terephthalate, Polybutylene Terephthalate (PBT), Acrylonitrile Butadiene Styrene (ABS).

[0036] In another alternative embodiment, a rope comprises an elongated core covered, or at least partially covered, by a sheath, wherein the core is comprised of a plurality of hybrid strands braided together, according to the teachings on rope hybridization described. Therefore, in this embodiment, the rope's core could be referred to as a hybrid core, since said core comprises a plurality of braided hybrid strands.

[0037] In this embodiment, the sheath covering the core can be an ordinary sheath, obtained under any known technique, or, alternatively, the sheath can also be a hybrid sheath as described above, so that all components of the rope, core and sheath, are of a hybrid type, according to the teachings of the invention.

[0038] With respect to this embodiment, the hybrid rope that forms the core comprises a base rope covered, according to the teachings of the invention, by a base covering rope, the base rope being made of a third material, and the covering rope of a fourth material.

[0039] In this sense, the first and third materials can be the same, while the second and fourth materials can also be the same. Alternatively, all materials can be different from each other, or combinations of materials for both the hybrid soul and the hybrid sheath, provided the hybridization concept as described is observed.

[0040] In another embodiment, the invention provides a method of manufacturing a rope comprising the steps of: providing an elongated core; and covering the core by braiding together a plurality of hybrid ropes, each hybrid rope being individually fed; wherein, in feeding, each hybrid rope is formed from forming a primary rope twisted a number of turns per meter; and overfeeding the primary rope with a covering rope, wrapping said covering rope around the base rope in the same twist direction as the latter.

[0041] In an alternative embodiment of the method, the step of forming a twisted primary rope comprises the step of: twisting a primary yarn around itself a number of turns per meter, or twisting a plurality of primary yarns together a number of turns per meter.

[0042] In another alternative embodiment of the method, the step of providing an elongated core comprises the steps of: forming a twisted base rope by twisting a base yarn around itself a number of turns per meter, or twisting a plurality of base yarns together a number of turns per meter, forming the core.

[0043] In another alternative embodiment of the method, the step of providing an elongated core comprises the additional step of: covering the twisted base rope with a base covering rope, wrapping said base covering rope around the base rope in the same twist direction as the latter, forming the core.

[0044] In another alternative embodiment, the stage of braiding together the plurality of hybrid ropes, in a first hybrid rope the base rope is twisted clockwise, and, in a second hybrid rope, the base rope is twisted counterclockwise.

[0045] BRIEF DESCRIPTION OF THE FIGURES

[0046] The above and other advantages and features will be more fully understood from the following detailed description of some embodiment examples with reference to the accompanying drawings, which are to be regarded as illustrative and not limiting, in which: Fig. 1 is a view of a hybrid rope, where the primary rope is twisted in one direction and is shown partially covered by the wrapping of the covering rope.

[0047] Fig. 2 is a view of a rope with a core covered with a hybrid sheath made by braiding hybrid ropes.

[0048] DETAILED DESCRIPTION OF AN IMPLEMENTATION EXAMPLE

[0049] The following detailed description presents numerous specific examples to provide a thorough understanding of the relevant teachings. However, it will be evident to those skilled in the subject that these teachings can be put into practice without such details.

[0050] As shown in Figure 1, the present invention provides a hybrid rope 4 intended for use in a technical rope 1, wherein said hybrid rope 4 can be arranged in the construction of the core 2 and / or the construction of the sheath 3 that constitute said rope 1.

[0051] In the illustrated example, the hybrid rope 4 is used to construct the sheath 3, thus obtaining a hybrid sheath 3 that covers the core 2. The hybrid sheath 3 therefore comprises a plurality of hybrid ropes 4, braided together and covering the core 2.

[0052] The hybrid rope 4 comprises a primary rope 40 twisted at a specified number of turns per meter, made of a first material. The primary rope 40 is covered by an overfed covering rope 41 wrapping around the primary rope 40, wherein the covering rope 41 is made of a second material.

[0053] Primary rope 40 is formed by a plurality of primary yarns arranged parallel to each other and twisted together a number of turns per meter, where the primary yarns are made from the first material.

[0054] The covering strand 41 comprises a parallel, i.e., untwisted covering thread, wherein the covering thread is made of the second material.

[0055] For this example embodiment, the materials to be hybridized will be polyamide for the primary rope 40 and aramid for the covering rope 41. The polyamide provides the mechanical properties of elasticity, necessary to absorb impacts or dynamic loads, such as a sudden elongation, while the aramid provides resistance to abrasion, produced, for example, by friction.

[0056] Now, in relation to rope 1, the core 2 is obtained by braiding a plurality of hybrid ropes 4 generating the hybrid sheath 3 that covers the core.

[0057] With respect to core 2, it comprises a base strand made from a plurality of yarns twisted a certain number of turns per meter, where the yarns, and therefore the base strand, are comprised of a third material. Alternatively, core 2 is made from a plurality of yarns twisted together. In this example, the third material is polyamide.

[0058] Therefore, rope 1 is provided with a hybrid braided sheath 3 that covers the twisted core 2, where both the core 2 and the sheath 3 work together. This hybrid sheath 3 provides dynamic impact resistance through the polyamide yarns, while heat and friction resistance are provided by the aramid yarn. Rope 1 with this construction has a reduced diameter, for example, between 4 and 10 mm, and at the same time is capable of passing the mechanical and dynamic tests specified in European standards.

Claims

CLAIMS 1. Rope (1) comprising: an elongated core (2); and a sheath (3) configured to cover the core (2), the sheath (3) comprising a plurality of hybrid ropes (4) twisted together covering the core (2), where each hybrid rope (4) comprises: a primary rope (40) twisted a number of turns per meter, and a covering rope (41) configured to cover the primary rope (40), where the covering rope (41) is arranged wrapped around the primary rope (40) in the same twisting direction as the latter.

2. Rope according to claim 1 wherein each primary strand (40) is formed by a primary yarn twisted upon itself a number of turns per meter, wherein the primary yarn is made from a first material.

3. Rope according to claim 1 wherein each primary strand (40) is formed from a plurality of primary strands arranged twisted together a number of turns per meter, wherein each primary strand within the plurality of primary strands is made from a first material.

4. Rope according to any of the preceding claims, wherein the covering end (41) is made from a second material.

5. Rope according to any of the preceding claims, wherein the core (2) comprises: a base rope twisted a number of turns per meter; and a base covering rope configured to cover the base rope, wherein the base covering rope is arranged wrapped around the base rope in the same twist direction as the latter.

6. Rope according to claim 5 wherein the base rope is formed by one or more ropes twisted upon themselves a certain number of turns per meter, wherein the base rope is made from a third material.

7. Method for manufacturing a rope (1) comprising the steps of: providing an elongated core (2); and covering the core (2) by braiding together a plurality of hybrid ropes (4), each hybrid rope (4) being individually fed; wherein, in the feeding, each hybrid rope (4) is formed from forming a primary rope (40) twisted a number of turns per meter; and covering the primary rope (40) with a covering rope (41), wrapping said covering rope (41) around the base rope (40) in the same twist direction as the latter.

8. Method according to claim 7, wherein the step of forming a twisted primary rope (40) comprises the step of twisting a primary yarn around itself a number of turns per meter, or twisting a plurality of primary yarns together a number of turns per meter.

9. Method according to any of claim 7 or 8, wherein the step of providing an elongated core (2) comprises the steps of: forming a twisted base rope by twisting a base yarn around itself a number of turns per meter, or twisting a plurality of base yarns together a number of turns per meter; and covering the twisted base rope with a base covering rope, wrapping said base covering rope around the base rope in the same twist direction as the latter, forming the core, wherein the base covering rope is formed from an untwisted covering yarn.

10. Hybrid rope (4) comprising: a primary rope (40) twisted a number of turns per meter; and a covering rope (41) disposed wrapped around the primary rope (40) in the same twist direction as the latter, wherein the primary rope (40) is made of a first material and the covering rope (41) is made of a second material.

11. Sheath (3) comprising a plurality of hybrid ropes (4) braided together, wherein, within the plurality of hybrid ropes (4), each hybrid rope (4) is a hybrid rope (4) according to claim 10.

12. Rope (1) comprising an elongated core (2) covered by a sheath (3) according to claim 11.

13. Rope (1) according to claim 12, wherein the core (2) comprises a hybrid rope (4) or a plurality of hybrid ropes (4), according to claim 10, braided together.

Images