MUSCLE TRAINER AND METHOD FOR THE PRODUCTION THEREOF

Abstract

A muscle trainer comprising curved, elongate spring elements is disclosed. The spring elements are arranged with facing concave sides and include end areas formed at each of the ends of the spring elements. The muscle trainer includes a first joint element being formed at a first end area of each spring element and a second joint element being formed at a second end area of each spring element. The spring elements are connected at their two end areas via joints formed from the joint elements. The first joint elements are designed as brackets having a bend in the direction of the concave side of the respective spring element and in each case at least partially enclosing the second joint element of the respective other spring element. A method for producing the muscle trainer and its use as a hand trainer are disclosed.

Claims

1. A muscle trainer comprising a first curved, elongate spring element and a second curved, elongate spring element, the two spring elements being arranged with their concave sides facing each other, end areas being formed at each of the ends of the two spring elements, a first joint element being formed at a first end area of each spring element and a second joint element being formed at a second end area of each spring element, and the spring elements being connected to each other at their two end areas via joints formed from the joint elements, wherein the first joint elements are designed as brackets, the brackets having a bend in the direction of the concave side of the respective spring element and in each case at least partially enclosing the second joint element of the respective other spring element, the second joint elements, being designed as a roller or rounded, and the brackets each forming a bearing in which the respective enclosed second joint element is mounted rotatably.

2. The muscle trainer according to claim 1, wherein the muscle trainer consists of precisely two spring elements.

3. The muscle trainer according to claim 1, wherein the first spring element and the second spring element have an identical geometry.

4. The muscle trainer according to claim 1, wherein a respective joint element of the first spring element establishes a form-fit connection with a joint element of the second spring element, which form-fit connection prevents a lateral movement of the first spring element relative to the second spring element.

5. The muscle trainer according to claim 4, wherein the form-fit connection is formed by in each case a snap-in hook on the second joint element, which snap-in hook in each case engages in a corresponding opening in the first end area of the respective other spring element, the snap-in hook interacting with the opening to establish a further form-fit connection which prevents a movement, in the longitudinal direction, of the first spring element relative to the second spring element.

6. The muscle trainer according to claim 5, wherein the snap-in hook has a projection which, by interaction with the opening in the first end area, establishes a form-fit connection which prevents a vertical movement of the first spring element relative to the second spring element.

7. The muscle trainer according to claim 1, wherein the first spring element and the second spring element are both free of undercuts.

8. The muscle trainer according to claim 1, wherein the two spring elements are produced from a thermoplastic, said thermoplastic being chosen in particular from polyoxymethylene (POM), polybutylene terephthalate (PBT), polyamide (PA), acrylonitrile-butadiene-styrene (ABS) and polypropylene (PP).

9. The muscle trainer according to claim 8, wherein the thermoplastic is fiber-reinforced.

10. The muscle trainer according to claim 9, wherein an opposing force of the spring elements is adjustable through a choice of a fiber content in the thermoplastic, the fiber content being chosen in a range from 1% by weight to 50% by weight.

11. The muscle trainer according to claim 1, wherein the spring elements each comprise a grip on a force introduction area.

12. The muscle trainer according to claim 11, wherein the grip is produced from a thermoplastic polyurethane (TPU).

13. The muscle trainer according to claim 11, wherein the grip has, on the concave side of the spring element, a spacer for limiting the bending.

14. A method for producing a muscle trainer according to claim 1, comprising the steps of: a) producing the first spring element and the second spring element by injection molding using an injection mold, b) arranging the first spring element and the second spring element such that their concave sides face each other and such that, at the ends of the spring elements, a first joint element adjoins a second joint element of the respective other spring element, c) bending the ends of the first spring element and of the second spring element by applying a force to the spring elements, d) snapping a second joint element into a respective first joint element, such that the first joint elements each at least partially enclose a second joint element of the respective other spring element, and e) terminating the force application, wherein the joint elements of the spring elements form joints.

15. A method for training hand muscles comprising actuating a muscle trainer according to claim 1.

Description

[0060] In the figures:

[0061] FIG. 1 shows a first embodiment of a muscle trainer in a view from the front,

[0062] FIG. 2 shows a perspective view of an attached joint of the muscle trainer,

[0063] FIG. 3 shows the muscle trainer of the first embodiment in a view from above,

[0064] FIG. 4A shows an attached joint in the undeformed state of the muscle trainer in a view from the front,

[0065] FIG. 4B shows an attached joint in the deformed state of the muscle trainer in a view from the front,

[0066] FIG. 5 shows a front view of a spring element of an embodiment as a hand trainer with grips,

[0067] FIG. 6 shows the hand trainer with grips in a view from below,

[0068] FIG. 7 shows a test arrangement for determining the stiffness of the muscle trainer,

[0069] FIG. 8 shows a force-travel diagram for various illustrative embodiments of the hand trainer.

[0070] In the following description of the illustrative embodiments of the invention, identical or similar elements are designated by identical reference signs, and the description of said elements is not repeated in every instance. The figures are purely schematic depictions of the subject matter of the invention.

[0071] FIG. 1 shows a first embodiment of a muscle trainer 1 in a view from the front. The muscle trainer 1 comprises two elongate, curved spring elements 11,12, namely a first spring element 11 and a second spring element 12.

[0072] The two spring elements 11, 12 are crescent-shaped in the view from the front, a first joint element 15 being arranged at a first end area 13 and a second joint element 16 being arranged at a second end area 14. The two spring elements 11,12 are arranged relative to each other in the muscle trainer 1 in such a way that their concave sides face each other.

[0073] The direction parallel to a connection of the two end areas 13, 14 of the crescent shape is designated as the longitudinal direction. The direction extending perpendicularly with respect to the drawing plane in FIG. 1 is designated as the transverse direction. The vertical direction is perpendicular both to the longitudinal direction and also to the transverse direction.

[0074] In the illustrative embodiment shown, the first joint element 15 of the first spring elements 11, 12 is designed as a bent bracket 18, wherein the area of a bracket 18 directly adjoining the spring element 11, 12 is curved in the same direction as the respective spring element 11,12 but has a much smaller bend radius. In the embodiment shown in FIG. 1, the bracket does not tangentially adjoin the form of the spring element 11, 12 and is instead arranged at an angle.

[0075] In the illustrative embodiment shown, the second joint element 16 of the spring elements 11, 12 is designed as a roller 24, wherein the radius of a roller 24 corresponds substantially to the bend radius of a bracket 18. The rollers 24 are oriented with their axes parallel to the transverse direction and each adjoin an end of the spring elements 11, 12. A bracket 18 forms a bearing in which a roller 24 is rotatably mounted. In further variants, instead of rollers 24 as second joint elements 16, it is possible, for example, for the second end areas 14 of the spring elements 11, 12 to be rounded, wherein the radius of the rounding preferably corresponds to the bend radius of the bracket 18.

[0076] At the center, the spring elements 11, 12 have force introduction areas 8. When the muscle trainer 1 is actuated, forces act on the force introduction areas 8 perpendicularly with respect to the spring elements 11, 12. In this way, the spring elements 11, 12 bend elastically. No bending stresses or only very slight bending stresses occur at the end areas 13, 14 of the spring elements 11, 12, since the joint elements 15, 16 permit a rotation. The greatest bending load occurs at the center of the spring elements 11, 12 and decreases in the direction of the end areas 13, 14. Accordingly, it is preferable to vary the wall thickness of the spring elements 11, 12 in accordance with the bending load, wherein the spring elements 11, 12 have their greatest wall thickness 7 at the center, and the wall thickness decreases toward the end areas 13, 14, such that the spring elements 11, 12 have their smallest wall thickness 6 at the end areas 13, 14. The longitudinal extent of the spring elements 11, 12 is indicated by reference sign 2 in FIG. 1 and is related to the unloaded state.

[0077] FIG. 2 shows a perspective view of a joint of the muscle trainer 1.

[0078] The joint of the muscle trainer 1 shown in FIG. 2 is formed from the first joint element 15 of the first spring element 11 and from the second joint element 16 of the second spring element 12.

[0079] The first joint element 15 of the first spring element 11 is a bracket 18 which is curved in the same direction as the first spring element 11 but which has a substantially smaller bend radius. The curvature of the bracket 18 does not tangentially adjoin the curvature of the first spring element 11. An angle, which is less than 180, is enclosed between the part of the bracket 18 bordering the spring element 11 and the convex side of the first spring element 11.

[0080] The second joint element 16 of the second spring element 12 is rounded and, in the illustrative embodiment shown, designed as a roller 24, wherein the radius of the roller 24 corresponds substantially to the bend radius of a bracket 18. The axis 22 of the roller 24 is oriented parallel to the transverse direction. The bracket 18 forms a bearing 20, in which a roller 24 is mounted rotatably.

[0081] The second joint element 16 has, in addition to the roller 24, a snap-in hook 26, with a projection 28 arranged at the end of the snap-in hook 26. The snap-in hook 26 with the projection 28 extends through an opening 30 in the bracket 18. A width 34 of the opening 30 is chosen such that it corresponds to the width of the snap-in hook 26, with the result that a form-fit connection is established which prevents a movement between the two spring elements 11 and 12 in the transverse direction. The length 32 of the opening 30 is substantially greater than the corresponding dimension of the snap-in hook 26, such that a rotational movement of the second joint element 16 in the first joint element 15 is still possible. In the unloaded state, the snap-in hook 26 bears with the projection 28 on the edge of the opening 30 facing toward the center of the first spring element 11, wherein the snap-in hook 26, by means of form-fit connection, prevents a relative movement of the spring elements 11 and 12 in the longitudinal direction. In addition to the interaction of bracket 18 and roller 24, the projection 28 on the snap-in hook 26 prevents a relative movement of the two spring elements 11, 12 in the vertical direction. When the muscle trainer 1 is actuated by forces being applied to the force introduction areas 8 of the spring elements 11, 12, the snap-in hook 26 with the projection 28 moves to the opposite side of the opening 30, wherein a relative movement separating the joint elements 15, 16 is ruled out on account of the acting force.

[0082] The muscle trainer 1 of the first embodiment, described with reference to FIGS. 1 and 2, is shown in a view from above in FIG. 3.

[0083] In this view from above, in conjunction with the view from the front in FIG. 1, it will be seen that the shape of the spring elements 11, 12 can be described as a perpendicular cylinder segment, which has the crescent-shaped base surface visible in FIG. 1. The view from above likewise shows that the snap-in hook 26 with its projection 28 of the second joint element 16 of the second spring element 12 is pushed through the opening 30 in the bracket 18 of the first spring element 11. The bracket 18 of the second spring element 12 at least partially encloses the second joint element 16 of the first spring element 11 (not visible in FIG. 3; cf. FIG. 1),

[0084] In the illustrative embodiment shown in FIGS. 1 to 3, the width 5 of the spring elements 11, 12 is constant along the entire length 2 of the spring elements 11, 12.

[0085] FIG. 4A shows an attached joint in the unloaded or undeformed state of the muscle trainer 1 in a view from the front. In FIG. 4B, the attached joint is shown in the loaded or deformed state of the muscle trainer 1 in a view from the front. In order to better illustrate the function of the attached joint, the first spring element 11 is shown partially in section in FIGS. 4A and 4B.

[0086] As has already been described with reference to FIGS. 1 and 2, the first joint element 15 of the first spring element 11 is designed as a bracket 18, which is curved in the same direction as the first spring element 11. The bend radius of the bracket is smaller than the bend radius of the curvature of the spring elements 11, 12 and corresponds to the radius of the second joint element 16 designed as roller 24. The curvature of the bracket 18 does not tangentially adjoin the curvature of the first spring element 11. An angle, which is less than 180, is enclosed between the convex side of the bracket 18 and the convex side of the first spring element 11.

[0087] The second joint element 16 is designed as a roller 24 and is mounted rotatably in the bearing 20 formed by the bracket 18.

[0088] The second joint element 16 has, in addition to the roller 24, the snap-in hook 26, with a projection 28 arranged at the end of the snap-in hook 26. The snap-in hook 26 with the projection 28 extends through an opening 30 in the bracket 18.

[0089] In the unloaded state shown in FIG. 4A, the snap-in hook 26 bears with the projection 28 on the edge of the opening 30 facing toward the center of the first spring element 11, wherein the snap-in hook 26, by means of form-fit connection, prevents a relative movement of the spring elements 11 and 12 in the longitudinal direction and the projection 28 prevents a relative movement of the spring elements 11 and 12 in the vertical direction.

[0090] FIG. 4B shows the muscle trainer 1 in a loaded state brought about by actuation of the muscle trainer 1. When forces are applied to the force introduction areas 8 of the spring elements 11, 12, the snap-in hook 26 with the projection 28 moves to the opposite side of the opening 30. At maximum loading, when the curvature of the spring elements 11, 12 is canceled out, the snap-in hook 26 preferably bears on the outwardly facing edge of the opening 30.

[0091] FIG. 5 shows an embodiment of the spring elements 11, 12 for a muscle trainer 1 designed as a hand trainer. Since both spring elements 11, 12 are identical, only one of the spring elements 11, 12 is shown in order to provide a better view of the joint elements.

[0092] As has already been described with reference to FIG. 1, the spring elements 11, 12 have, at their first end area 13, a first joint element 15 designed as a bracket 18 and, at their second end area, a second joint element 16 designed as a roller 24. A snap-in hook 26 with a projection 28 is additionally arranged on the roller 24.

[0093] The spring element 11, 12 of the hand trainer shown in FIG. 5 has, at the force introduction area 8, a force introduction element in the form of a grip 36. The grip 36 encloses the spring element 11, 12 in the force introduction area 8 thereof. The grip 36 is preferably made from a material other than that of the spring elements 11, 12. In order to improve the haptics, a material is preferably chosen here which is soft by comparison with the material of the spring elements 11, 12. For example, the grip 36 can be made from a non-foamed or a foamed polyurethane.

[0094] In the embodiment shown in FIG. 5, the grip 36 is produced from a compact non-foamed thermoplastic polyurethane (TPU). Moreover, the spring element 11, 12 has a spacer 38 arranged on the concave side, which spacer 38, in this embodiment, is produced in one piece with the grip 36. The maximum possible bending of a hand trainer formed from two spring elements 11, 12 is limited by the spacer 38.

[0095] The wall thickness of the spring element 11, 12 in FIG. 5 varies along the length of the spring element 11, 12, wherein the spring element 11, 12 has its greatest wall thickness 7 at the center, and the wall thickness decreases toward the end areas 13, 14, such that the spring element 11, 12 has its smallest wall thickness 6 at the end areas 13, 14. The longitudinal extent of the spring element 11, 12 is indicated by reference sign 2 in FIG. 5 and is related to the unloaded state.

[0096] FIG. 6 shows a muscle trainer 1 which is composed of two of the spring elements 11, 12 shown in FIG. 5 and which is designed as a hand trainer. FIG. 6 shows the hand trainer in a view from below.

[0097] In contrast to the muscle trainer of the first embodiment shown in FIGS. 1 and 3, the width of the spring element 11, 12 is not constant and instead increases from the center to the end areas 13, 14. The spring elements 11, 12 thus have their smallest width 5 and the center and have their greatest width 30 at their end areas 13, 14. In conjunction with a variation of the wall thickness of the spring elements 11, 12, which is preferably greatest at the center as shown in FIG. 5, the stress in the spring elements 11, 12 is uniform along their entire length 2 in such an embodiment.

[0098] FIG. 7 shows a schematic view of a test arrangement for determining the stiffness of a muscle trainer.

[0099] To determine the stiffness, a force-travel measurement is carried out in which a deformation travel 48 is determined. For this purpose, the muscle trainer 1 to be tested is placed on a table 46, wherein one of the spring elements 12 bears with its force introduction area 8 on the table 46. A force F is exerted on the force introduction area 8 of the other spring element 11 via a ram 44. The distance between the two spacers 38 thereby decreases from a first distance 40 to a second distance 42. The difference between the first distance 40 and the second distance 42 corresponds to the deformation travel 48.

[0100] The deformation travel 48 and the associated force F are recorded during the measurement.

[0101] FIG. 8 shows a force-travel diagram for various illustrative embodiments of the hand trainer.

[0102] In the diagram in FIG. 8, the deformation travel is plotted in mm on the X axis and the force is plotted in N on the Y axis. The diagram shows measurements for six different examples of a hand trainer which each have identical dimensions and differ only in terms of the fiber content of the plastic used for the spring elements. The spring elements were produced from polyoxymethylene (POM) with fiber contents of 0% by weight, 5% by weight, 10% by weight, 12.5% by weight, 15% by weight and 20% by weight.

[0103] From the force-travel curves in FIG. 8, it will be seen that the hand trainers present a slightly non-linear behavior in the case of a short deformation travel, wherein the force needed for a defined deformation is increased with an increasing fiber content, in the hand trainers with spring elements made from the fiber-reinforced material. The hand trainer composed of the non-reinforced material has a more pronounced non-linear characteristic, such that the force required for a deformation up to approximately 3 mm deformation is initially approximately as high as in the case of the hand trainer with a fiber content of 10% by weight. At a deformation travel of 10 mm, the force required for the deformation of the hand trainer composed of non-reinforced material corresponds to that of the hand trainer with a fiber content of 5% by weight. Above 10 mm, all hand trainers composed of materials reinforced with fibers have a greater required force than the hand trainer composed of the non-reinforced material. At the maximum tested deformation travel of 20 mm, the non-reinforced plastic has the lowest force, and the force needed fro a deformation of 20 mm increases with an increasing fiber content in the plastic.

LIST OF REFERENCE SIGNS

[0104] 1 muscle trainer

[0105] 2 length

[0106] 4 width

[0107] 5 width at the center

[0108] 6 wall thickness of the end areas

[0109] 7 wall thickness at the center

[0110] 8 force introduction area

[0111] 11 first spring element

[0112] 12 second spring element

[0113] 13 first end area

[0114] 14 second end area

[0115] 15 first joint element

[0116] 16 second joint element

[0117] 18 bracket

[0118] 20 bearing

[0119] 22 axis

[0120] 24 roller

[0121] 26 snap-in hook

[0122] 28 projection

[0123] 30 opening

[0124] 32 long opening

[0125] 34 wide opening

[0126] 36 36 grip

[0127] 38 spacer

[0128] 40 distance, unloaded

[0129] 42 distance, loaded

[0130] 44 ram

[0131] 46 table

[0132] 48 deformation travel

[0133] F force application