Muscle trainer and method for the production thereof

Abstract

Described herein is a muscle trainer including a first and a second curved, elongate spring element, the two spring elements being arranged with their concave sides facing each other, having joint elements at their respective end areas and being connected to each other at their two end areas via joints formed from the joint elements. Also described herein is a method for producing such a muscle trainer.

Claims

1. A muscle trainer having a first curved, elongate spring element and a second curved, elongate spring element, wherein the two spring elements are arranged with their concave sides facing each other, each of the spring elements has joint elements at their respective end areas and the spring elements are connected to each other at their two end areas via joints formed from the joint elements in order to form the muscle trainer, wherein the muscle trainer is formed in one piece or consists of the first spring element and the second spring element, and wherein the joint elements of the first spring element are designed as brackets, the brackets being bent in the direction of the concave side of the first spring element and partially enclosing the joint elements of the second spring element, wherein the joint elements of the second spring element are rollers or have a rounded configuration, and a first joint element in form of a bracket in each case forms a bearing in which the respective second joint element of the second spring element is rotatably mounted.

2. The muscle trainer according to claim 1, wherein the joint elements of the first spring element are designed as snap-action elements, the joint elements of the second spring element are designed as latching elements, and the latching elements are received in the snap-action elements.

3. 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, wherein the form-fit connection prevents a lateral movement of the first spring element relative to the second spring element.

4. The muscle trainer according to claim 3, wherein the form-fit connection is provided by in each case at least one projection on the joint elements of the second spring element, said at least one projection engaging in each case in a corresponding opening or in corresponding recesses on the joint elements of the first spring element.

5. The muscle trainer according to claim 3, wherein the form-fit connection is provided by a change in the wall thickness of the spring elements across their width.

6. The muscle trainer according to claim 5, wherein the first spring element has, in the area of each of its joint elements, a rib which engages in a corresponding groove in the area of the joint elements of the second spring element.

7. The muscle trainer according to claim 5, wherein the wall thickness of the first spring element, seen across the width of the first spring element, is greatest at the center and decreases toward the side edges, and the wall thickness of the second spring element, seen across the width of the second spring element, is accordingly at its smallest at the center and increases toward the side edges.

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

9. The muscle trainer according to claim 1, wherein the two spring elements of the one-piece muscle trainer are connected to each other by resilient arcs arranged on each of the convex sides.

10. The muscle trainer according to claim 1, wherein the two spring elements are produced from a thermoplastic.

11. The muscle trainer according to claim 10, wherein the thermoplastic is chosen from polyoxymethylene (POM), polybutylene terephthalate (PBT), polyamide (PA), acrylonitrile-butadiene-styrene (ABS) and polypropylene (PP).

12. 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 at least one injection mold, b) bending the first spring element by applying force to the two end areas of the first spring element and/or curving the second spring element by applying force to the two end areas of the second spring element, c) inserting the second spring element into the first spring element, d) terminating the force application onto the first spring element and/or onto the second spring element, wherein the joint elements of the first spring element and of the second spring element form joints.

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

Description

(1) Illustrative embodiments of the invention are shown in the figures and are explained in more detail in the following description.

(2) In the figures:

(3) FIG. 1 shows a first embodiment of a muscle trainer in a view from the front,

(4) FIG. 1a shows the muscle trainer of the first embodiment configured as a hand trainer with gripping elements, in a view from the front,

(5) FIG. 2 shows the muscle trainer of the first embodiment in a view from below,

(6) FIG. 3 shows a further embodiment of the muscle trainer in a view from below,

(7) FIG. 4 shows a perspective view of a first embodiment of a first spring element,

(8) FIG. 5 shows a perspective view of a first embodiment of a second spring element,

(9) FIG. 6 shows a perspective view of a second embodiment of a first spring element,

(10) FIG. 7 shows a perspective view of a second embodiment of a second spring element,

(11) FIG. 8 shows a perspective view of a third embodiment of a first spring element,

(12) FIG. 8a shows the third embodiment of the first spring element in a view from the front,

(13) FIG. 9 shows a perspective view of a third embodiment of a second spring element,

(14) FIG. 10 shows a perspective view of a variant of the third embodiment of a second spring element,

(15) FIG. 11 shows a fourth embodiment of a first and second spring element,

(16) FIG. 12 shows a one-piece embodiment of a hand trainer in a view from the front,

(17) FIG. 13 shows the one-piece embodiment of a hand trainer in a view from above,

(18) FIG. 14 shows a test arrangement for determining the stiffness of the muscle trainer, and

(19) FIG. 15 shows a force-travel diagram for various illustrative embodiments of the hand trainer.

(20) 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.

(21) 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 10, namely a first spring element 11 and a second spring element 12.

(22) The two spring elements 10 are crescent-shaped in the view from the front, in each case a joint element 14 being arranged at the respective end areas 13. The two spring elements 10 are arranged relative to each other in the hand trainer 1 in such a way that their concave sides face each other.

(23) In the illustrative embodiment shown, the joint elements 14 of the first spring element 11 are designed as bent brackets 16, wherein the area of a bracket 16 directly adjoining the first spring element 11 is curved in the same direction as the spring element 11 but has a much smaller bend radius. The bracket 16 runs in an area which has no curvature.

(24) In the illustrative embodiment shown, the corresponding joint elements 14 of the second spring element 12 are designed as rollers 18, wherein the radius of a roller 18 corresponds substantially to the bend radius of a bracket 16. The rollers 18 are oriented with their axes parallel to the transverse direction and each adjoin an end of the second spring element 12. A bracket 16 forms a bearing in which a roller 18 is rotatably mounted. In further variants, instead of rollers 18 as joint elements 14 of the second spring element 12, it is possible, for example, for the end areas 13 of the second spring element 12 to be rounded, wherein the radius of the rounding preferably corresponds to the bend radius of the bracket 16.

(25) At the center, the spring elements 10 have force introduction areas 50. When the muscle trainer 1 is actuated, forces F act on the force introduction areas 50 perpendicularly with respect to the spring elements 10. In this way, the spring elements 10 bend elastically. No bending stresses or only very slight bending stresses occur at the end areas 13 of the spring elements 10, since the joint elements 14 permit a rotation. The greatest bending load occurs at the center of the spring elements 10 and decreases in the direction of the edge areas 13. Accordingly, it is preferable to vary the wall thickness of the spring elements 10 in accordance with the bending load, wherein the spring elements 10 have their greatest wall thickness 20 at the center, and the wall thickness decreases toward the end areas 13, such that the spring elements 10 have their smallest wall thickness 22 at the end areas 13. The longitudinal extent of the spring elements 10 is indicated by reference sign 28 in FIG. 1.

(26) FIG. 1a is a view from the front showing an embodiment of the muscle trainer 1 as a hand trainer, with force introduction elements 52 designed as gripping elements. The hand trainer shown in FIG. 1a corresponds to the muscle trainer 1 described with reference to FIG. 1, except that the spring elements 10 each have a force introduction element 52 in the form of a gripping element at the force introduction areas 50. The gripping elements are preferably made from a material other than that of the spring elements 10. In order to improve the haptics, a material is preferably chosen here which is soft by comparison with the material of the spring elements 10. For example, the gripping elements 52 can be made from an expanded polyurethane.

(27) The spring action of the muscle trainer 1 is set through the choice of the geometry of the spring elements 10 and through the choice of the material of the spring elements 10, in such a way that the maximum spring force lies in a range suitable for the use as a hand trainer. For this purpose, the maximum spring force is preferably set such that it lies in the range of 40 to 150 N. The maximum spring force lies particularly preferably in the range of 50 to 100 N.

(28) The muscle trainer 1 of the first embodiment, described with reference to FIG. 1, is shown in a view from below in FIG. 2.

(29) In this view from below, in conjunction with the view from the front in FIG. 1, it will be seen that the shape of the spring elements 10 can be described as a perpendicular cylinder segment, which has the crescent-shaped base surface visible in FIG. 1. It will likewise be seen in the view from below that the brackets 16 of the first spring element 11 at least partially enclose the second spring element 12 or the corresponding joint elements 14 thereof (not visible in FIG. 2; cf. FIG. 1).

(30) FIG. 3 shows a further embodiment of the hand trainer 1 in a view from below. As has been described with reference to FIG. 1, the muscle trainer 1 has two spring elements 10 which are connected to each other at their end areas 13 via joint elements 14. In addition to or as an alternative to a variation of the wall thickness, provision is made, in the embodiment in FIG. 3, to vary the width of the spring elements 10 along the longitudinal extent 28. Since the greatest bending load occurs at the center of the spring elements 10, the spring elements 10 preferably have the greatest width 26 at the center. The width decreases in the direction of the edge areas 13, such that the smallest width 24 of the spring elements 10 is present at the edge areas 13.

(31) FIG. 4 is a perspective view showing a detail of a first embodiment of a first spring element 11. As has already been described with reference to FIG. 1, the first spring element 11 has, at each of its end areas 13, a respective joint element 14 in the form of a bracket 16, only one end area 13 being visible in FIG. 4. The bracket 16 is arranged in such a way that the first spring element 11 transitions smoothly into the bracket 16. The bracket 16 is bent in the direction of the concave side of the first spring element 11. The bracket 16 has an area of strong curvature adjoining the first spring element 11 and running out, at its other end, in an area without curvature.

(32) It will be seen from the view in FIG. 4 that the width of the bracket 16 is smaller than the width of the first spring element 11. Recesses 32 are located on both sides of the bracket 16, wherein the bracket 16 is arranged in a centered position, seen across the width of the spring element 11.

(33) FIG. 5 is a perspective view showing a detail of a first embodiment of a second spring element 12. At its end area 13, the second spring element 12 has a joint element 14, which is designed as a roller 18. On the side opposite the spring element 12, the joint element 14 is adjoined by two projections 30. The orientation of the projections 30 is chosen in such a way that they are arranged in a direct continuation of the second spring element 12. A recess 32 is located between the two projections 30. The size, in particular the width, of the recess 32 is chosen such that the bracket 16 of the first spring element 11 shown in FIG. 4 can engage in the recess 32 between the two projections 30, and a form-fit connection is thereby established which prevents a relative movement between the first spring element 11 and the second spring element 12 in the transverse direction. Since the roller 18 is additionally mounted in the bracket 16, the form-fit connection also prevents a relative movement between the first spring element 11 and the second spring element 12 in a vertical direction.

(34) FIG. 6 is a perspective view showing a detail of a second embodiment of a first spring element 11. As has already been described with reference to FIGS. 1 and 4, the first spring element 11 has, at its end area 13 visible in FIG. 6, a joint element 14 in the form of a bracket 16 which is bent in the direction of the concave side of the first spring element 11. The bracket 16 has an area of strong curvature adjoining the first spring element 11 and running out at its other end in an area without curvature.

(35) In the illustrative embodiment shown in FIG. 6, the width of the bracket 16 corresponds to the width of the first spring element 11, and the bracket 16 is arranged in such a way that the first spring element 11 transitions smoothly into the bracket 16. In the area of greatest curvature of the bracket 16, the latter has an opening 34. The opening 34 is arranged centrally as seen across the width of the first spring element 11.

(36) FIG. 7 is a perspective view showing a detail of a second embodiment of a second spring element 12. In the embodiment shown, the second spring element 12 has, at each of its end areas 13, a joint element 14 which is designed as a rounding 36. The radius of curvature of the rounding 36 preferably corresponds here to half the wall thickness of the second spring element 12 at the respective end, such that a smooth transition is present between the second spring element 12 and the roundings 36.

(37) At each of its end areas 13, the second spring element 12 of the second embodiment has a projection 30, of which the width corresponds approximately to the width of the opening 34 of the second embodiment of the first spring element 11 shown in FIG. 6. In the assembled state of the muscle trainer 1, a form-fit connection is established between the projection 30 and the opening 34 and suppresses a relative movement between the first spring element 11 and the second spring element 12 in directions parallel to the transverse direction and parallel to the vertical direction. The rounding 36 is in this case mounted in a bearing formed by the bracket 16. The height of the opening 34 is preferably greater than the thickness of the projection 30, in order to permit a pivoting movement in the formed bearing when the muscle trainer is actuated.

(38) FIG. 8 is a perspective view showing a detail of a third embodiment of a first spring element, and FIG. 8a shows the first spring element 11 of the third embodiment in a view from the front.

(39) As has already been described with reference to FIGS. 1 and 4, the first spring element 11 has, at its end area 13 visible in FIG. 8, a joint element 14 in the form of a bracket 16 which is bent in the direction of the concave side of the first spring element 11. The bracket 16 has an area of strong curvature adjoining the first spring element 11 and running out at its other end in an area without curvature.

(40) A rib 38 is arranged on the surface of each of the brackets 16 facing toward the concave side of the first spring element 11. The rib 38 can be seen only in the view from the front in FIG. 8a. The rib 38 is preferably arranged centrally with respect to the width of the first spring element 11. The ribs 38 constitute an abrupt change of the wall thickness in the areas of the brackets 16 of the first spring element 11. The rib 38 preferably establishes a form-fit connection with a corresponding groove 40 of a joint element 14 of the second spring element 12. In addition to or as an alternative to the provision of the ribs 38, provision can be made that, with respect to the width of the bracket 16, the wall thickness, starting from the edge, continuously increases or decreases in the direction of the rib 38.

(41) FIG. 9 is a perspective view showing a detail of a third embodiment of a second spring element 12.

(42) The second spring element 12 shown in FIG. 9 has, at its end area 13, a joint element 14 which is designed in the form of two truncated cones 42. The two truncated cones 42 are arranged in such a way that the top surfaces of the truncated cones 42 face each other. The cone axes of the truncated cones 42 are oriented parallel to the transverse direction. Located between the two truncated cones 42 there is a free space in the form of a groove 40, which can establish a form-fit connection together with a rib 38 of the first spring element 11. The angle between the cone axis and the surface line of the truncated cones 42 is preferably chosen such that it corresponds to the variation of the wall thickness of the bracket 16 of the first spring element 11 and likewise establishes a form-fit connection.

(43) If the bracket 16 of the first spring element 11 has no further variation in wall thickness other than the rib 38, the joint element 14 is preferably designed as a roller 18 with a groove 40 at the center, wherein the roller 18 can also be regarded as two truncated cones 42 with an angle of 0 between the cone axis and the surface line.

(44) If the first spring element 11 of the third embodiment has only a continuous variation of the wall thickness, and no rib 38, the groove 40 between the two truncated cones 42 can be omitted. This is shown in FIG. 10.

(45) FIG. 11 shows a fourth embodiment of a first spring element 11 and of a second spring element 12 in a view from the front. FIG. 11 shows the two spring elements 10 in an assembled state of the muscle trainer 1.

(46) The two spring elements 10 have joint elements 14 at each of their end areas 13, wherein the joint elements 14 of the first spring element 11 are designed as snap-action elements 44 and the joint elements 14 of the second spring element 12 are designed as latching elements 46.

(47) The latching elements 46 and the snap-action elements 44 both represent functional elements which together produce a snap-fit connection between the first spring element 11 and the second spring element 12. The snap-action element 44 represents the functional element which, in the resulting form-fit connection, at least partially encloses the functional element designated as latching element 46.

(48) The snap-action elements 44 and the latching elements 46 are preferably designed as vertical cylinders, wherein the latching element 46 in the illustrative embodiment shown is in the form of a vertical circular cylinder. In the example shown in FIG. 11, the snap-action element is designed as a cylinder with a circular ring segment as base surface, wherein the cutout from the circular ring is greater than 180. Thus, the latching element 46 is enclosed by the snap-action element 44 in such a way that the snap-action element 44 has to be elastically deformed in order to release or produce the snap-fit connection.

(49) The form-fit connection limits a relative movement between the two spring elements 10 in such a way that accidental separation of the two spring elements 10 is suppressed or at least made difficult.

(50) The embodiments described with reference to FIGS. 4 to 5 and 8 to 10 can also be combined with the embodiment described with reference to FIG. 11.

(51) FIG. 12 shows a one-piece embodiment of a muscle trainer 1 designed as a hand trainer, in a view from the front.

(52) The muscle trainer 1 shown in FIG. 12 and designed as a hand trainer is designed in one piece and comprises two elongate curved spring elements 10, namely a first spring element 11 and a second spring element 12. The two spring elements 10 are crescent-shaped in the view from the front, wherein a respective joint element 14 is arranged on each of the end areas 13. The two spring elements 10 are arranged relative to each other in the muscle trainer 1 in such a way that their concave sides face each other.

(53) The muscle trainer 1 is shown in a state in which the joint elements 14 of the spring elements 10 are not yet brought together to form joints. In the illustrative embodiment shown, the joint elements 14 of the first spring element 11 are designed as bent brackets 16, wherein the area of a bracket 16 directly adjoining the first spring element 11 is curved in the same direction as the spring element 11 but has a much smaller bend radius. The bracket 16 runs out in an area that has no curvature.

(54) In the illustrative embodiment shown, the corresponding joint elements 14 of the second spring element 12 are designed as roundings 36, wherein the radius of the roundings corresponds substantially to half the wall thickness of the second spring element 12 in the edge area 13 thereof and likewise substantially corresponds to the bend radius of the bracket 16. The roundings 36 each adjoin the ends of the second spring element 12 and merge seamlessly into the second spring element 12. A bracket 16 here forms a bearing in which the rounding 36 can be mounted rotatably.

(55) In the one-piece muscle trainer 1, the two spring elements 10 are connected to each other via two resilient arcs 48. For this purpose, the spring elements 10 each have, at their end areas 13, connections to one of the resilient arcs 48. The resilient arcs 48 permit a relative movement between the two spring elements 10, such that the initially still separate joint elements 14 can be brought together to form the joints. For assembly, a force is applied for example to the end areas 13 of the first spring element 11, such that the first spring element 11 deforms and the curvature of the first spring element 11 is reduced. The second spring element 12 is then inserted into the first spring element 11, such that a joint element 14 of the first spring element 11 forms a joint with a joint element 14 of the second spring element 12 after the force has been removed from the first spring element 11. After assembly, the two spring elements 10 are connected to each other at their end areas 13 by a joint and a resilient arc 48.

(56) At the center, the spring elements 10 have force introduction areas 50. When the muscle trainer 1 designed as a hand trainer is actuated, forces F act on the force introduction areas 50 perpendicularly with respect to the spring elements 10. In this way, the spring elements 10 bend elastically. No bending stresses or only very slight bending stresses occur at the end areas 13 of the spring elements 10, since the joint elements 14 permit a rotation. The greatest bending load occurs at the center of the spring elements 10 and decreases in the direction of the edge areas 13. In the embodiment shown in FIG. 12, the wall thickness 20 of the spring elements 10 is constant along their entire length. In further embodiments, it is preferable to vary the wall thickness of the spring elements 10 in accordance with the bending load, wherein the spring elements 10 have their greatest wall thickness 20 at the center, and the wall thickness decreases toward the end areas 13.

(57) In FIG. 13, the one-piece embodiment of the muscle trainer 1 designed as a hand trainer is shown in a view from above. The muscle trainer 1 is not yet assembled. The second spring element 12 is completely concealed by the first spring element 11.

(58) In the embodiment shown in FIG. 13, the width of the two spring elements 10 does not vary along the length of the spring elements 10, with the result that the spring elements 10 have the constant width 26. It will likewise be seen from the view in FIG. 13 that the width of the resilient arcs 48 is much smaller than the width of the spring elements 10. The resilient arcs 48 are preferably arranged centrally, seen with respect to the width of the spring elements 10.

(59) FIG. 14 shows a schematic view of a test arrangement for determining the stiffness of a muscle trainer.

(60) To determine the stiffness, a force-travel measurement is carried out in which a deformation travel 64 is determined. For this purpose, the muscle trainer 1 to be tested is placed on a table 62, wherein one of the spring elements 12 bears with its force introduction area 50 on the table 62. A force F is exerted on the force introduction area 50 of the other spring element 11 via a ram 60. The distance between two spacers 54 thereby decreases from a first distance 66 to a second distance 68. The difference between the first distance 66 and the second distance 68 corresponds to the deformation travel 64. The maximum spring force and the maximum spring deformation can be limited by the spacers 54 introduced between the force introduction areas 50 of the two spring elements 11, 12. In this case, the curvature of the spring elements 11, 12 is not completely canceled even when the maximum spring force is applied.

(61) In the design variant of the hand trainer 1 shown in FIG. 14, the two spring elements 11, 12 are each identical.

(62) The deformation travel 64 and the associated force F are recorded during the measurement.

(63) FIG. 15 shows a force-travel diagram for various illustrative embodiments of the hand trainer.

(64) In the diagram in FIG. 15, 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.

(65) From the force-travel curves in FIG. 15, 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 constantly increases with an increasing fiber content in the hand trainers with spring elements made from the fiber-reinforced material.

LIST OF REFERENCE SIGNS

(66) 1 muscle trainer 10 spring element 11 first spring element 12 second spring element 13 end area 14 joint element 16 bracket 18 roller 20 wall thickness center 22 wall thickness end area 24 width end area 26 width center 28 length 30 projection 32 recess 34 opening 36 rounding 38 rib 40 groove 42 truncated cone 44 snap-action element 46 latching element 48 resilient arc 50 force introduction area 52 force introduction element 54 spacer 60 ram 62 table 64 deformation travel 66 distance, unloaded 68 distance, loaded F force application