Round sling

Abstract

The invention relates to a round sling consisting of a load-bearing inner fabric, wherein the inner fabric is formed from an endless coil of at least one carrying thread and a protective cover in the form of a textile protective tube surrounding the inner fabric with radial degree of freedom, wherein the at least one carrying thread is formed from a plurality of parallel plied single threads as roving, which forms a yarn bundle and the yarn bundle has at least one further thread that winds around the yarn bundle.

Description

[0001] The invention relates to a round sling for lifting loads. Round slings have an inner core that supports a load. The inner core, also called the liner, is formed from an endless coil of a multitude of parallel load-bearing threads and is provided with a protective sheath in the form of a textile tube that surrounds the inner core with radial freedom.

[0002] It is known from the prior art that the supporting threads of the inner layer of the round loop are twisted as an endless coil. The supporting threads are generally formed from a twisted roving, as described for example in DE 20 2019 103 172 U1.

[0003] The technically determined fineness of a twisted yarn used as load-bearing threads results in a high number of turns in the inner layer of the round sling. This is particularly true for round slings with high load-bearing capacities. Due to the high number of turns, the risk of an inhomogeneous winding increases, meaning the load-bearing threads no longer run parallel to each other. For example, during the manufacturing process of the round sling, such as when inserting it into the protective sheath, sagging, non-load-bearing threads of the inner layer can occur, leading to a reduction in the load-bearing capacity of the round sling.

[0004] Furthermore, when using high-performance fibers, such as HMPE, twisting the supporting threads is disadvantageous, even with fine yarns, because although high-performance fibers have high tensile strength, twisting such filaments during twisting is detrimental, as the resulting shear forces within the filaments can reduce their strength. Task

[0005] The invention aims to optimize the aforementioned disadvantages of the prior art and to provide a round sling that is improved compared to the prior art. It also aims to ensure that the number of windings of the inner layer of the round sling can be reduced, or at least that the risk of inhomogeneous windings of the inner layer during the production of a round sling is reduced, or that the tensile strength of high-performance fibers used as roving is maintained. Solution to the task

[0006] This problem is solved according to the invention by a round loop with the features of main claim 1, wherein the dependent claims include further embodiment variants of these solutions according to the invention.

[0007] A round sling consists in a known manner of an inner layer that bears a load, wherein the inner layer is formed from an endless coil of at least one supporting thread and the endless coil thus has a plurality of supporting threads running essentially parallel to each other and a protective cover in the form of a textile protective tube surrounding the inner layer with radial degree of freedom.

[0008] According to the invention, the at least one supporting thread is formed as a roving from a plurality of parallel, and thus parallel, individual threads, forming a yarn bundle. This yarn bundle includes at least one further thread as a so-called auxiliary thread, also called a wrapping thread, which wraps around the yarn bundle, i.e., surrounds the yarn bundle externally and thus fixes the yarn bundle in its parallel arrangement of the rovings. The yarn bundle, and thus the parallel set of threads formed by the individual threads, is limited in its radial extent so that it cannot become uncontrollably entangled with the adjacent windings, particularly during the production of round loops. This ensures that the tension of the individual threads is maintained even during the production of round loops.

[0009] The winding spacing is chosen in such a way that the previously described effect of limiting the radial expansion of the yarn bundle of at least one further thread, also called a winding thread, is ensured.

[0010] In a further embodiment, the yarn bundle is provided with at least two additional threads as auxiliary threads, which alternately wind around the yarn bundle. The two additional threads cross each other as winding threads.

[0011] Furthermore, it can be provided that the at least one additional thread is made of the same material as the roving. This improves the recyclability of the round loop. However, it is also within the scope of the invention that the at least one additional thread, as a wrapping thread, is made of a different material than the roving and is designed to be biodegradable. It can be provided that the at least one additional thread is biodegradable upon contamination with a medium, for example water, and dissolves.

[0012] In one variant of the invention, insofar as the at least one supporting thread does not consist of a high-performance fiber, the yarn bundle itself has a defined overall fineness that is higher than the overall fineness of a conventional twisted yarn bundle known to those skilled in the art.

[0013] It should be noted that without the solution according to the invention, coarse densities at the defined overall fineness described above cannot be achieved technologically with a twisted carrying thread. Therefore, the number of thread turns required to form a round loop can be reduced, in contrast to the use of twisted carrying threads. This also positively influences the uniformity of the winding of a plurality of essentially parallel carrying threads. If high-performance fibers are used as roving, the density can also be less coarse. Since, as already explained, the tensile strength of high-performance fibers decreases with twisting, the twisting can be omitted by using at least one additional thread as a wrapping thread, thus preventing the aforementioned disadvantage of reduced tensile strength, regardless of the density.

[0014] According to the invention, it is also possible for the thread length of the support threads, which are wound onto spools during the manufacturing process, to be greater than that of twisted support threads. This reduces interruptions in the production process of round sling manufacturing caused by changing spools holding support threads. The need to knot additional support threads to the support threads during the production of the inner layer of round slings is also reduced. A known support thread in the form of a coarse yarn has a length of approximately 750 m, meaning that additional support threads must be knotted after reaching this length. The solution according to the invention thus also optimizes the production process, as the aforementioned need to knot additional support threads is reduced. Production downtime for round slings due to knotting is therefore minimized.

[0015] Furthermore, the production process of the inner layer of the round sling is more controllable due to the decreasing number of windings and the fixing of the yarn bundle by means of the wrapping thread. This also ensures more effectively that the load-bearing threads lie parallel to each other when inserted into the protective sheath of the round sling during the production process.

[0016] The invention is further explained below with reference to an exemplary embodiment and the figures. This will reveal further advantages, features, and embodiments of the invention.

[0017] They show: Fig. 1. A schematic representation of a round sling in cross-section Fig. 2 a schematic representation of a section of a carrying thread of a round sling Fig. 3 Another schematic representation of a section of a carrying thread of a round sling

[0018] Fig. Figure 1 represents a strand section of a round sling 1. The round sling 1 consists, in a known manner, of an inner layer 2 that bears a load. The inner layer 2 is formed from an endless coil of a load-bearing thread 3. The endless coil, in the form of a plurality of essentially parallel sections of the load-bearing thread 3, has a protective sheath 4 in the form of a textile sleeve surrounding the inner layer 2 with radial freedom.

[0019] In the exemplary embodiment, the support thread 3 is, as in Fig. 1 and Fig. 2, as can be seen, is formed from a plurality of parallel plied single threads as roving, which form a yarn bundle 5. The yarn bundle 5 has a further thread 6 as an auxiliary thread, which winds around the yarn bundle 5 and thus fixes the yarn bundle 5 in its mutually parallel arrangement of the rovings.

[0020] In Fig. Figure 3 shows an embodiment of the round loop 1 according to the invention, namely a supporting thread 3 as a yarn bundle 5, wherein the yarn bundle 5 has two further threads 6, 6' as auxiliary threads that alternately wind around the yarn bundle 5. The two further threads 6, 6' cross over each other as winding threads. The crossing of the two further threads 6, 6' in Fig. 3 does not occur alternately, which is also within the scope of the invention, but rather another thread 6 always crosses the other thread 6' at a defined winding distance 7. Reference symbol list 1. Round sling 2. Inner layer 3. Carrying thread 4. Protective cover 5. Yarn bundle 6. further thread 7. Coil spacing QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2019 103 172 U1

[0002]

Claims

[1] Round sling (1) consisting of a load-bearing inner layer (2), wherein the inner layer is formed from an endless coil of at least one carrying thread (3) and a protective cover (4) surrounding the inner layer (2) with radial degree of freedom in the form of a textile protective tube, which is formed from at least one carrying thread (3) of a plurality of parallel plied single threads as roving, forming a yarn bundle (5), characterized by , that the yarn bundle (5) has at least one further thread (6) that winds around the yarn bundle (5). [2] Round loop (1) according to claim 1, wherein the yarn bundle (5) has at least two further threads (6), (6') which alternately wind the yarn bundle (5) towards each other. [3] Round loop (1) according to one of claims 1 or 2, wherein the at least one further thread (6) is made of the same material as the roving. [4] Round loop (1) according to one of claims 1 or 2, wherein the at least one further thread (6) is degradable upon contamination with a medium.

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