ROUND SLING

Description

[0001] The invention relates to a round sling for lifting loads. Round slings have an inner core that supports the load. The inner core, also called the liner, is formed from an endless coil of numerous parallel load-bearing threads and is provided by a protective sheath in the form of a textile tube that surrounds the inner core with radial freedom. The protective sheath of the round sling can be multi-layered, with the two layers being bonded together, as is known from DE 92 14 173 U1. This allows for improved visual inspection for damage to a layer.

[0002] In the past, to improve the elasticity of the protective hose, textile fabrics with fiber components or yarns with a high elongation capacity relative to their tensile strength were used, so-called stretch yarns, as disclosed in DE 10 2011 052 146 A1 or DE 92 09 857 U1.

[0003] Textile fabrics forming the protective sleeve are also known, in which the protective sleeve is a textile fabric woven from warp and weft threads, wherein the warp threads running in the longitudinal direction (L) or longitudinal extension of the protective sleeve consist of fibers or yarns with low elongation relative to their high tensile strength, and the weft threads have high elongation relative to their tensile strength. They consist, for example, of stretch fibers or stretch yarns, as disclosed in DE 10 2011 052 146 A1 and also in FR 2 959 223 A1.

[0004] When a round sling is used as a lifting sling, and a tensile force is applied—for example, to a load, a lifting device, or a lifting hook—the fabric expands transversely to its longitudinal direction (L). The resulting increase in the required amount of tubing material is provided by the stretching of the weft threads, which involves the warp threads becoming entangled or shifting within the previously dense fabric. With the high elasticity of a conventional single-layer elastic tubular fabric, beyond a certain stretch, the necessary entanglement of the warp threads to maintain a closed fabric surface is no longer guaranteed. Consequently, the warp threads can easily shift within the fabric structure, and the tubing becomes prone to developing holes.These tissue dilations or openings represent weak points, as foreign bodies or similar objects can penetrate the protective sheath through them. It is also possible that exposed threads can be dislodged from the tissue structure by external influences.

[0005] The object of the invention is to optimize the disadvantage of tissue expansion or tissue opening under load in a protective sleeve as described above.

[0006] The problems were solved by a round sling according to main claim 1, wherein the dependent claims include more advantageous further embodiments of the invention. Accordingly, the round sling according to the invention has the following features.

[0007] The round sling consists of a load-bearing inner layer, the inner layer being formed from an endless coil of multiple essentially parallel load-bearing threads, so-called yarn coils, and a protective cover surrounding the inner layer with radial freedom in the form of a textile protective tube. The protective tube is a textile fabric woven from warp and weft threads, the textile fabric consisting of a multi-layered fabric. The fabric layers each have warp threads running in the longitudinal direction (L), also called longitudinal extension, of the protective tube. These warp threads consist of fibers or yarns with low elongation relative to their high tensile strength. The weft threads, running essentially transversely to the longitudinal direction, in the transverse direction Q and thus also transversely to the warp threads, have high elongation relative to their tensile strength.wherein the fabric layers of the multilayered fabric are connected to one another by further weft threads running transversely to the longitudinal direction (in the transverse direction Q), so-called connecting threads, which exhibit a high elongation capacity relative to their tensile strength. Within the scope of the invention, the multilayered fabric can consist of two or more than two layers.

[0008] Advantageously, the additional weft threads act as connecting threads, linking the warp threads of the multi-layered fabric in such a way that they interlock with the warp threads, for example, with each warp thread, of the multi-layered fabric.

[0009] The elasticity of the other weft threads is equal to or less than the elasticity of the weft threads of the multilayered fabric.

[0010] When weft threads and further weft threads are mentioned in the plural, this can also refer, in the sense of the invention, to a single weft thread or a further weft thread from a spool of the device for manufacturing the protective hose, or to threads from several spools.

[0011] Whenever the terms elongation capacity or extensibility are used, they always refer to elastic elongation in the context of the invention. It therefore concerns elastic elongation.

[0012] The length of the weft threads and / or subsequent weft threads can be stretched by, for example, 180 percent or more in the elastic range, and in a preferred embodiment up to 250 percent, which is what is meant by high elongation. The high elongation of the weft threads and / or subsequent weft threads is thus 1.8 to 2.5 times greater in the elastic range.

[0013] It should be mentioned that, moreover, it is known to the skilled person that the elongation capacity of the protective sleeve is also influenced by the elongation capacity of the weft threads, and that the weft density, the type of binding, and the type of interlacing of the threads also have an influence on the elongation capacity.

[0014] The weft threads and / or the further weft threads can, within the scope of the invention, consist of an elastane fiber wrapped with polyester, a high-performance fiber spun with an elastic fiber, or another suitable material.

[0015] In a further embodiment, the protective sleeve has two layers of fabric which, in the case of an asymmetrical structure of the protective sleeve, have a different number of, but at least one additional weft thread per weave repeat. A combination of one or more connecting threads as additional weft threads is also within the scope of the invention in order to achieve different properties of the layers with regard to elongation behavior and compactness, and to tailor these to the respective required properties of the protective sleeve.

[0016] The solution according to the invention creates a more closed fabric structure, thus reducing fabric expansion or openings in the protective sleeve of the round sling under load. The formation of holes and the risk of foreign bodies penetrating the protective sleeve are therefore reduced.

[0017] The invention is further explained below with reference to two exemplary embodiments and the figures. This will reveal further advantages, features, and configurations of the invention.

[0018] They show: Fig. 1 a schematic representation of a fabric of a protective sleeve of a round loop in a relaxed state, wherein the further weft threads interlock with each warp thread of the two fabric layers. Fig. 1.1 a schematic representation of the fabric of a protective sleeve of a round loop in a tensioned state, wherein the further weft threads interlock with each warp thread of the two fabric layers. Fig. 2 a schematic representation of another fabric of a protective sleeve of a round loop in a relaxed state, wherein the further weft threads float over three warp threads of the two fabric layers before crossing with the layers. Fig. 2.1a schematic representation of another fabric of a protective sleeve of a round sling in a tensioned state, wherein the further weft threads float over three warp threads of the two fabric layers before crossing with the layers.

[0019] In both embodiments, the multi-layered fabric consists of only two layers of fabric.

[0020] The respective elastic weft threads 1 and 1' form in combination with the warp threads 3 / 1 until 3 / 4 a first layer of tissue 2. The elastic weft threads 1'' and 1‴ form with the warp threads 3 / 5 until 3 / 8 another layer of tissue 4. The warp threads 3 the first tissue layer 2 and the further tissue layer 4 run in the longitudinal direction L, that is, in the direction of the longitudinal axis of the loop. In the transverse direction Q, perpendicular to the longitudinal direction LThe weft threads run along the round loop. 1' to 1‴. The first and subsequent tissue layers are connected. 2, 4 through additional elastic weft threads 5, which also in a transverse direction Q get lost, Fig. 1 .

[0021] Under transverse stress, the first and subsequent tissue layers expand. 2, 4 according to Fig. 1.1 . The spaces that normally occur between the warp threads in a single-layer transversely elastic fabric 3 / 1 until 3 / 4 the first tissue layer 2 are now being worked with the warp threads 3 / 5 until 3 / 8 the further tissue layer 4 occupied and thus completely or at least partially filled. When the protective sleeve of the round sling is stretched transversely. Q The overlapping warp threads, due to the tension of the further weft threads 5, tend to arrange themselves side by side, Fig. 1.1 . The warp threads 3 / 1until 3 / 8 lie in the transverse direction after stretching the protective sleeve of the round sling Q therefore in the arrangement 3 / 5, 3 / 1, 3 / 6, 3 / 2, 3 / 7, 3 / 3, 3 / 8 and 3 / 4.

[0022] Fig. 2 shows a further embodiment of the round sling according to the invention, wherein in the Fig. 2 and 2.1 as in the Fig. 1 and 1.2 A schematic representation of a section of a protective sleeve of the round sling as part of a textile fabric is shown. A cross-sectional representation of the round sling itself, with its inner core consisting of a plurality of essentially parallel strands running lengthwise, is also shown. L The formation of continuous supporting threads as an endless coil, wherein the inner fabric with radial degree of freedom is surrounded and enclosed by the protective sleeve as a textile surface product, does not occur, as this is known to the skilled person from the prior art described above.

[0023] Fig. 2 and 2.1show, as an example, a different arrangement of the additional weft threads. 5 in the fabric of the protective sleeve of the round sling, the fabric being also multi-layered and consisting of the first and the subsequent fabric layer 2, 4 consists and, apart from the entry of the further weft threads, 5 same as the first embodiment according to the Fig. 1 and 1.1 . is trained.

[0024] In this embodiment, the elastic weft threads float. 5 over three warp threads 3, before they interlock with the tissue layers, which is in contrast to the arrangement in Fig. 1 , which provides for an interlacing with each warp thread, leads to a less strong binding and thus a greater elasticity of the fabric of the protective tube of the round loop in the transverse direction Q enables what is in Fig. 2.1 . is shown. The warp threads 3 / 1 until 3 / 8lie in the transverse direction after stretching the protective sleeve of the round sling Q in the same arrangement as in Fig. 1.1 . shown and explained in advance. Generally, a floating of the further weft threads is also possible. 5 over two or more warp threads 3 This occurs before they cross over the tissue layers.

[0025] The elongation behavior of the fabric of the protective sleeve of the round loop is also influenced by the frequency of the insertion of the additional weft threads. 5 affected, so that in addition to a double shot, the suspension of the insertion of further weft threads is also affected. 5 This is possible over several weft threads, so that the protective sleeve has the most homogeneous elongation behavior possible in the transverse direction. Q This can be achieved. This depends on the specific requirements placed on the round sling according to the invention.

[0026] According to the two exemplary embodiments, only a limited number of warp threads are available in a two-layer protective sleeve. Therefore, the advantageous effect according to the invention decreases with increasing elongation of the protective sleeve in the transverse direction. Q so that if the round sling is overloaded, a hole-forming widening of the multi-layered fabric of the protective hose is to be expected, which can additionally represent an indication of an overload, so that the expert must immediately stop handling the round sling in the event of such an indication. Reference symbol list:

[0027] 1. Weft threads 2. First layer of fabric 3. Warp threads 4. Second layer of fabric 5. Second weft threads Q: Cross direction L: Longitudinal direction

Claims

1. A round sling, consisting of an inner structure accommodating a load, wherein said inner structure is formed from an endless spool of a plurality of carrying yarns running substantially parallel to each other, and a protective sheath surrounding the inner structure with a radial degree of freedom, said protective sheath having the form of a textile protective sleeve, wherein the protective sleeve is a warp and weft (3), (1) woven textile sheet product, wherein the textile sheet product consists of a multilayer fabric the fabric layers of which each have the warp yarns (3) running in the longitudinal direction (L) or the longitudinal extension of the protective sleeve, characterized in that the warp yarns consist of fibers or threads with low elasticity relative to their high tensile strength and in that the weft yarns (1) running perpendicular to the longitudinal direction in the perpendicular direction (Q) have high elasticity relative to their tensile strength, wherein the fabric layers of the multilayer fabric are connected to each other by further weft yarns (5) running perpendicular to the longitudinal direction and having high elasticity relative to their tensile strength.

2. The round sling according to Claim 1, wherein the further weft yarns (5) connect the warp yarns (3) of the multilayer fabric as connecting yarns, which leads to interlacing with warp yarns (3) of the multilayer fabric.

3. The round sling according to Claim 1, wherein the further weft yarns (5) connect the warp yarns (3) of the multilayer fabric as connecting yarns, which leads to interlacing with each warp yarn (3) of the multilayer fabric.

4. The round sling according to any one of the preceding claims, wherein the protective sleeve has two fabric layers and the two fabric layers have different numbers of, but at least one, further weft yarn(s) (5) per weave repeat in an asymmetrical structure of the protective sleeve.

5. The round sling according to any one of the preceding claims, wherein the multilayer fabric consists of two or more than two layers.

6. The round sling according to any one of the preceding claims, wherein the protective sleeve has two fabric layers and the further weft yarns (5) float over two or more warp yarns (3) of the two fabric layers before interlacing with the fabric layers.

7. The round sling according to any one of the preceding claims, wherein the elasticity of the further weft yarns (5) is the same or lower than the elasticity of the weft yarns (1) of the multilayer fabric.

8. The round sling according to any one of the preceding claims, wherein the high elasticity of the weft yarns (1) and / or the further weft yarns (5) is 1.8 to 2.5 times greater in the elastic range.

9. The round sling according to any one of the preceding claims, wherein the weft yarns (1) and / or the further weft yarns (5) consist of an elastane fiber enwrapped in polyester or of a high-performance fiber spun together with an elastic fiber.

10. The round sling according to any one of the preceding claims, wherein the elastic behavior of the fabric of the protective sleeve of the round sling depends on the insertion frequency of the further weft yarns (5).