Expander with degressive voltage behavior

Abstract

Expander (100) for training the muscles, featuring - an elastic element (110) that can be expanded for training against its restoring force, characterized in that the elastic element (110) consists of a composite of at least two different elastic materials (120, 130), wherein - a first elastic material (120) is present as a closed line pattern with an offset or unoffset fourfold or with a sixfold unit cell (E), wherein the closed line pattern is present as boundary lines (121) of the tiles (122) of a tiling, and wherein - another elastic material (130) fills the surfaces of the tiles (121).

Description

[0001] The invention relates to an expander for training the muscles, comprising an elastic element which can be expanded against its restoring force for training purposes, and to a method for producing such an expander.

[0002] Expanders are well-known as training devices for strengthening muscles. Typical designs include handles connected by elastic rubber bands, which can be pulled apart through appropriate exercises. Expanders also consist of an elongated latex band. The latex band is available as an open band or as a closed band ring. A typical exercise with a latex ring involves wrapping the latex band around the body and stretching the limbs against the restoring force of the latex band.

[0003] The disadvantage of existing expanders is that the restoring force is linear within the elastic range of longitudinal extension. During a leg or arm extension movement, the arm or leg opens by extending the joint. With the arm closed, the required force exerted by the corresponding extensor muscle is comparatively high, since the angle of attack for the muscle is very unfavorable for an extension movement due to the position of the joint.

[0004] A further disadvantage of the linear restoring force factor in the working range is that it is less suitable for training fast muscle movements. For training fast extension movements, such as those common for a boxer or generally common in martial arts and Olympic disciplines such as javelin throwing, it would be desirable for the restoring force to remain relatively constant along the muscle movement as early and as long as possible. A typical exercise is to place an expansion band around the hips, with the arms positioned inside the expansion band. The trainee then performs sudden extension movements of the arms. Near the hips, the restoring force is initially linear, which is desirable.However, for rapid muscle contraction training to be successful, it would be desirable if the extending arm, during a boxing movement, could extend close to the extended arm against a constant force, or at least against a force that no longer increases as much.

[0005] Generating a constant restoring force with an isotropic elastic material appears impossible. This would contradict the well-known Hooke's law. Elastic materials generally exhibit a range of elasticity with a roughly constant elastic modulus, in which the force exerted by a linear extension is proportional to the linear extension itself. At the end of the elastic range, the elastic modulus increases, meaning the increase in restoring force increases with increasing linear extension. Training for fast and powerful muscle movements, in which as much force as possible is transformed into movement speed, thus enabling higher final speeds, is therefore inefficient.

[0006] The German translation DE 692 27 199 T2 of European patent EP 0 627 986 B1 discloses a woven, elastic net consisting of two basic components. The warp threads and weft threads are made of different materials, so that the net exhibits a different elasticity in the direction of the warp threads than in the direction of the warp threads. A net of this type is suitable for packaging bundles of small items of various types. The less elastic direction holds the items together, while the more elastic direction gently holds the items together.

[0007] The German patent application DE 10 2004 056 220 A1 discloses an elastic towel which, in addition to its function as a towel, can also be used as a fitness exercise device.

[0008] Finally, US patent US 4,273,328 A discloses a back brace that a user can wear to support a straight posture. This brace features both non-elastic loops that can be tightened around the shoulders, as well as an elastic band that connects the two loops and is stretched across the upper back when worn. The elasticity pulls the user's shoulders back, thereby maintaining a straight back posture.

[0009] The object of the invention is to provide an expander which shows a degressive voltage behavior.

[0010] The object of the invention is achieved by an expander having the features of claim 1. Further advantageous embodiments are specified in the subclaims to claim 1. Methods for producing the expander are specified in claims 7 to 10.

[0011] According to the invention, the expander is constructed from an elastic material, wherein the elastic material is a composite material. The composite material is anisotropic. The anisotropy, i.e. the property of exhibiting different material properties in different spatial directions, changes with longitudinal expansion. This change in anisotropy is achieved by the geometric structure of a latticework of the composite material changing with longitudinal expansion, thereby changing the orientation of the elastic structural elements relative to the longitudinal expansion. Such a structure is constructed similarly to a latticework and takes the form of a so-called tiling. A tiling is a closed surface made up of a limited set of different geometric individual parts, where the individual parts within a set are identical.In the simplest case, there is only a single set of geometric figures, namely identical squares within the set. It is also possible to construct a tiling with matching squares and triangles. For small numbers of sets, namely n = 1, 2, 3, or 4, tilings that lead to a closed surface exist in only a small number and multiplicity. The multiplicity is the number of sides of the geometry of the unit cell. Thus, there are square, i.e., four-fold unit cells, and there are hexagonal, i.e., six-fold unit cells of the tiling. Five-fold tilings are also known, but these are not regular. Furthermore, there are regular and staggered tilings in the four-fold tiling. The tiling consists of geometrically identical or congruent tiles within a set.

[0012] The expander's elastic composite material consists of at least two different elastomers. The first elastomer is constructed as a closed line pattern, with the lines representing the boundaries of the tiles in a tiling. The pattern is closed, meaning there are no free ends to any line; instead, each line ends in a point from which more than one further line branches off.

[0013] It has proven advantageous to ensure that the area ratio of the at least two elastic materials in the composite is approximately equal, with a relative deviation of one material from a uniform distribution of less than 10%. This leads to particularly pronounced effects in the change in elastic properties during longitudinal strain.

[0014] To enhance the effect of the change in the elastic modulus during longitudinal expansion, the additional elastic material can contain elastomer granules and / or gas bubbles with a diameter between 1 mm and 5 mm and an areal concentration of less than 20%. The additional elastomer is therefore not a foam, but rather an isotropic elastomer with defects that collapse during longitudinal expansion, as is the case with gas bubbles, or that resist transverse contraction, as is the case with the granules. It is important that distinct phase boundaries form between the elastic regions in the additional elastomer.

[0015] To produce such a composite material, it has proven advantageous to stamp a first elastomer into a closed line pattern as the boundary lines of the tiles in a tiling arrangement. This first elastomer is then embedded in another elastomer, such as latex or silicone.

[0016] To enhance the anisotropic effect, the punched portion of the first elastomer can be stretched during embedding, i.e., kept under tension. The change in length during stretching should be in the range of 5% to 20%, preferably between 8% and 11%, to prevent the formation of ripples or waves in the elastomer caused by the different restoring forces of the individual elements of the composite material.

[0017] The invention is explained in more detail with reference to the following figures. They show: Fig. 1 a sketch of an expander in the form of an elastic band and the use of the expander during training, Fig. 2 a sketch of an expander in the form of a closed loop and an application of the expander during training, Fig. 3 a stress-strain diagram of an expander made of an isotropic elastic material from the PRIOR ART, Fig. 4 a stress-strain diagram of an expander according to the invention, Fig. 5 a first structure of an elastic element with a six-fold unit cell, Fig. 6 a second structure of an elastic element with a six-fold unit cell, Fig. 7.1 a third structure of an elastic element with fourfold unit cell, Fig. 7.2 the second structure from Fig. 7.1 in stretched form, Fig. 8 a section of the composite material of the elastic element with embedded elastomer granulate, Fig. 9 a section of the composite material of the elastic element with embedded gas bubbles, Fig. 10 a section of the composite material of the elastic element with embedded elastomer granules and with embedded gas bubbles.

[0018] In Fig. Figure 1 shows a sketch of an expander 100 in the form of an elastic band 200 and the use of this expander 100 during training. For training, a band made of an elastic element is placed around the upper body or knotted into a ring, and a boxing motion is performed within the resulting elastic ring. This exercise is repeated many times to strengthen the muscles used. The exercise shown here is just one of many possible exercises.

[0019] In Fig. Figure 2 shows a sketch of an expander 100 in the form of a closed ring 300 and the use of the expander 100 during training. For training, the closed ring 300 is placed around the upper body, and a boxing motion is performed into the elastic ring 300. This exercise is repeated many times to strengthen the muscles used. The exercise shown here is just one of many possible exercises.

[0020] In Fig. Figure 3 shows a stress-strain diagram of an expander made of an isotropic elastic material from the PRIOR ART. An expander with an isotropic elastic material shown here is typically used in the range of an initial strain d1 with a constant elastic modulus ε1. In the final range of the elastic strain, a further strain d2 follows with an increased elastic modulus ε2, which is associated with a higher restoring force per further strain. The elastic modulus is no longer constant in the final range, but generally increases non-linearly. The exact course of the elastic modulus ε in the final range of the elastic range of an elastomer is highly material-specific and differs between rubber-elastic materials (entropy-elastic) and non-rubber-elastic materials.

[0021] In Fig. Figure 4 shows a stress-strain diagram of an expander according to the invention. The special feature of the expander according to the invention is that the elastic modulus ε decreases in the end region. Although the restoring force F increases with increasing strain x, the increase in the restoring force F is degressive. This type of stress-strain diagram of an expander is particularly interesting for training powerful, fast movements, such as pushing or striking movements. The further increase in the restoring force F decreases in the end region of the expander. Depending on the geometry of the composite structure, the degression is more or less non-linear. There are also composite structures in which the elastic composite structure suddenly collapses, resulting in a real kink or multiple kink(s) in the stress-strain diagram, forming regions with elastic moduli ε1, ε2, and ε3. In the diagram in Fig. 4 shows how the structure of the composite material in the elastic element 110 collapses in a marked working area extending over a kink of the elastic modulus ε1 and ε2.

[0022] Fig. 5 shows a first structure of an elastic element 110 with a six-fold unit cell E. The elastic element 110 consists of three different materials. A first elastic material is a punched section of a first elastic material 120 to form a closed line pattern with a six-fold unit cell E, wherein the closed line pattern is present as boundary lines 122 of the tiles 121 of a tiling. In this example, the tiling consists of geometrically identical tiles 121 made of another elastic material, wherein the area ratio of the at least two elastic materials in the composite is approximately equal, with a relative deviation of one material of less than 10% from a uniform distribution.A third material is formed by pieces of a third elastic material present in the tiles 121 in the form of a coarse elastomer granulate 140, the granules of which have a diameter between 1 mm and 5 mm and an areal concentration in the tiles of less than 20%.

[0023] Fig. 6 shows a second structure of an elastic element with a six-fold unit cell. The elastic element 110 consists of three different materials. A first elastic material is a punched section of a first elastic material 120 to form a closed line pattern with a six-fold unit cell E, wherein the closed line pattern is present as boundary lines 122 of the tiles 121 of a tiling. In this example, the tiling consists of geometrically identical tiles 121 made of another elastic material, wherein the area ratio of the at least two elastic materials in the composite is approximately equal, with a relative deviation of one material of less than 10% from a uniform distribution.A third material is formed by pieces of a third elastic material present in the tiles 121 in the form of a coarse elastomer granulate 140, the granules of which have a diameter between 1 mm and 5 mm and an areal concentration in the tiles of less than 20%.

[0024] In Fig. Figure 7.1 shows a third structure of an elastic element with a four-fold unit cell. The elastic element 110 consists of three different materials. A first elastic material is a punched section of a first elastic material 120 into a closed line pattern with a four-fold and rectangular unit cell E, with the closed line pattern being present as boundary lines 122 of the tiles 121 of a tiling.

[0025] In this example, the tiling consists of geometrically identical tiles 121 made of another elastic material, wherein the area ratio of the at least two elastic materials in the composite is approximately equal, with a relative deviation of one material from a uniform distribution of less than 10%. A third material is formed by pieces of a third elastic material present in the tiles 121 in the form of a coarse elastomer granulate 140, whose granules have a diameter between 1 mm and 5 mm and an area concentration in the tiles of less than 20%.

[0026] In Fig. 7.2 is the second structure from Fig. 7.1 in stretched form. Depending on the stretching direction, the Fig. 7.1 clearly visible zigzag or triangular line during expansion. Before the triangular line stretches, the restoring force is dominated by the entire composite of materials in elastic element 110. If the structure collapses, the restoring force is dominated almost exclusively by the linearized triangular lines. Due to their narrow width, these have less to resist an external force. Consequently, the elastic modulus decreases in a degressive manner with further stretching. The restoring force naturally increases with increasing elongation, but to a lesser extent.

[0027] In Fig. Figure 8 shows a section of the composite material of the elastic element 110 with embedded elastomer granulate 140. In this illustration, the elastomer tiles, tiles 121, are made of the structure in Fig. 6 shown.

[0028] In Fig. Figure 9 shows a section of the composite material of the elastic element with embedded gas bubbles 150. In this illustration, the elastomer tiles, tiles 121, are also cut out of the structure in Fig. 6 shown.

[0029] In Fig. 10 finally shows a section of the composite material of the elastic element 110 from Fig. 6 with embedded elastomer granules 140 and also with embedded gas bubbles 150. LIST OF REFERENCE SYMBOLS 100 expanders 110 elastic element 120 elastic material 121 Tile 122 boundary line 130 elastic material 140 elastomer granules 150 gas bubble 160 punching 200 elastic band 300 closed ring ε- elastic modulus d stretching E unit cell F Force x length

Claims

[1] Expander (100) for training the muscles, comprising - an elastic element (110) which can be expanded against its restoring force for training purposes, characterized by that the elastic element (110) consists of a composite of at least two different elastic materials (120, 130), wherein - a first elastic material (120) is present as a closed line pattern with a displaced or undisplaced four-fold or with a six-fold unit cell (E), wherein the closed line pattern is present as boundary lines (121) of the tiles (122) of a tiling, and wherein - another elastic material (130) fills the surfaces of the tiles (121). [2] Expander according to claim 1, characterized by that the tiling consists of geometrically identical or congruent tiles (122). [3] Expander according to one of claims 1 or 2, characterized bythat the area ratio of the at least two elastic materials (120, 130) in the composite is approximately equal with a relative deviation of one material of less than 10% from a uniform distribution. [4] Expander according to one of claims 1 to 3, characterized by that in the further elastic material (130) there are elastomer granules (140) and / or gas bubbles (150) which have a diameter between 1 mm and 5 mm and have an area concentration of less than 20%. [5] Expander according to one of claims 1 to 4, characterized by that it is present as an elastic band (200) [6] Expander according to one of claims 1 to 5, characterized by that it is present as a closed ring (300). [7] A method for producing an expander according to any one of claims 1 to 6, characterized by - punching a closed line pattern as boundary lines of the tiles of a tiling from a strip of a first elastic material (120), - embedding the previously obtained punch (160) in liquid latex or elastomer starting material, - Curing of the liquid latex or elastomer starting material. [8] Method according to claim 7, characterized by - stretching the punch (160) during the curing of the liquid latex or the elastomer starting material by a linear expansion of between 5% and 20%, preferably between 8% and 11%. [9] Method according to one of claims 7 or 8, characterized by - Embedding elastomer granules (140) in the latex or elastomer, wherein the elastomer granules (140) have a grain size of 1 mm to 5 mm and the surface concentration of the elastomer granules (140) in the latex or silicone is less than 20%. [10] Method according to one of claims 7 to 9, characterized by - foaming the liquid latex or elastomer starting material with gas bubbles (150) having a size between 1 mm and 5 mm, wherein the surface concentration of the gas bubbles in the latex or elastomer is less than 20%.

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