Patent Application
20190201729
The invention relates to a muscle trainer with two spring elements, and to a method for the production of the muscle trainer.
Various types of muscle trainers for building up muscles are known in the prior art. For example, hand trainers are used to strengthen the muscles of the hands. The user applies a force to the hand trainer and, by means of an elastic element, the hand trainer generates an opposing force. Conventional hand trainers use a metal spring as the elastic element. Such hand trainers have to be provided with suitable grips, which complicates their design and production. The grips are generally made from different materials, for example from a plastic. When such a hand trainer is actuated by the user, the grips are moved toward each other under the applied load and, when the load is removed, they spring back again to the starting position.
The utility model DE 20 2014 009 325 U1 discloses a hand trainer made of a relatively flexurally stiff surface element and of an elastic element, wherein the elastic element has a seat for the thumb, and the flexurally stiff surface element has further finger seats. The fingers other than the thumb are in this way brought into a fixed position relative to the thumb. The training device thus permits targeted training of the muscles of the thumb. Further parts of the hand muscles cannot be trained.
The laid-open specification DE 10 2012 108 655 A1 describes a fitness apparatus with elastic elements, wherein the elastic elements comprise polyurethane. Several elastic elements can be connected to one another in the fitness apparatus, resulting in a suitably stiffer elastic element. However, this connection requires a fixed union, which takes up quite a lot of space. Moreover, high levels of material stress occur at the connection when a load is applied.
It is an object of the invention to make available a muscle trainer that has a compact format and is easy to produce. It is a further object of the invention to ensure that the material stress occurring in a muscle trainer when actuated is kept as low as possible. The force needed for the actuation and the deformation that occurs should preferably be comparable to conventional muscle trainers.
A muscle trainer is proposed 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, characterized in that 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 shape of the two spring elements can, for example, be that of a substantially rectangular plate, wherein the rectangular plate has a long side and a shorter side. The end areas are arranged at the ends of the long side. The rectangular plate is curved, wherein the axis of curvature runs parallel to the short side and perpendicular to the long side. Setting aside the curvature of the spring element, the direction parallel to the short side is regarded as the transverse direction, the direction parallel to the long side is regarded as the longitudinal direction, and the direction perpendicular to the surface of the plate is regarded as the vertical direction. This shape of the spring elements can also be described as a perpendicular cylinder segment, wherein the base surface of the perpendicular cylinder segment is substantially crescent-shaped. The direction parallel to the connection of the two ends of the crescent shape is designated as the longitudinal direction, and the direction perpendicular to the base surface of the cylinder is designated as the transverse direction. The vertical direction is perpendicular both to the longitudinal direction and also to the transverse direction. The two end areas of a spring element are arranged at the ends of the crescent shape as described here.
The muscle trainer comprises two such elongate, curved spring elements, which are arranged relative to each other in the muscle trainer in such a way that their concave sides face each other. The two spring elements are connected to each other at their ends by joints. The muscle trainer is preferably composed of precisely two spring elements.
Each of the spring elements has a joint element at both of its end areas, wherein a respective first joint element of a spring element forms a joint together with a second joint element of the respective other spring element. The two joints thus formed connect the two spring elements in such a way that, when the muscle trainer is actuated with a force being applied parallel to the vertical direction, the connections between the two spring elements are advantageously subjected to no or only very slight bending loads and bending stresses. The greatest bending load is applied to the part of the spring element lying at the center between the two end areas. The term bending stress signifies the mechanical stress in the material. The spring element is preferably designed in such a way that the bending stress is maintained more or less constant along the length of the spring element. The term bending load signifies the bending moment, which decreases from the center of the spring element toward the edge.
When the muscle trainer is actuated, an opposing force is generated by the spring elements, and a person using the muscle trainer has to work against this opposing force. The magnitude of the opposing force is determined by the shape of the spring elements and by the material used and depends on the muscles that are to be exercised using the muscle trainer and/or on the training status of the user. The muscle trainer is preferably designed as a hand trainer.
The wall thickness of a spring element preferably varies in the longitudinal direction, i.e. along the length from one end to the other end, wherein the greatest wall thickness is preferably reached at the center. The greatest wall thickness preferably lies in the range of 2 to 8 mm and particularly preferably in the range of 3 to 6 mm. The smallest wall thickness preferably lies in the range of 0.5 to 5 mm and particularly preferably in the range of 1 to 3 mm. By virtue of the variation of the wall thickness, the spring element can be made strongest in those areas where the greatest bending loads occur. The first spring element and the second spring element preferably have the same wall thickness or the same profile of the wall thickness.
Alternatively or in addition, the width of the spring element, i.e. the length of the short side, can vary in the longitudinal direction. The spring element preferably has its greatest width at the end areas. Depending on the intended use, the greatest width preferably lies in the range of 20 mm to 150 mm. In the use as a hand trainer, the greatest width is preferably in the range of 20 mm to 50 mm and particularly preferably in the range of 25 mm to 35 mm. The smallest width preferably lies in the range of 5 mm to 100 mm. In the use as a hand trainer, the smallest width preferably lies in the range of 5 mm to 35 mm and particularly preferably in the range of 10 mm to 25 mm. If there is no variation of the width, then the width of the spring elements is preferably chosen in the range of 20 mm to 150 mm, or, in the use as a hand trainer, preferably in the range of 20 mm to 50 mm. The first spring element and the second spring element preferably have the same width or the same profile of the width.
The length of the spring elements, i.e. the extent in the longitudinal direction, preferably lies in the range of 150 mm to 350 mm, or, in the use as a hand trainer, particularly preferably in the range of 180 mm to 230 mm.
The muscle trainer is preferably actuated in such a way that force is applied in the area of the center of the surfaces of the spring elements. For this purpose, it is preferable for a force introduction area to be formed on each of the spring elements, such that the muscle trainer is easier for the user to use or grip. In the case where the muscle trainer is designed as a hand trainer, the force introduction areas are preferably designed as grips. The force introduction area is preferably formed at the center of the spring elements, viewed in the longitudinal direction of the spring elements.
The maximum spring force of the muscle trainer, providing an opposing force upon actuation, is set through the choice of the geometry of the spring elements and through the choice of the material of the spring elements and preferably lies in the range of 40 to 300 N and particularly preferably in the range of 50 to 120 N. The maximum spring force is reached when, under the application of force, the spring elements are deformed in such a way that the spring elements touch each other in the area of the center of the surfaces of the spring elements. In this state, the curvature of the spring elements is substantially canceled by the deformation. The maximum possible deformation upon actuation of the muscle trainer is defined by the greatest distance between the two spring elements and is predetermined by the curvature of the spring elements. The greatest distance between the two spring elements preferably lies in the range of 20 mm to 200 mm or, in the use as a hand trainer, particularly preferably in the range of 50 to 100 mm. The maximum spring force and the maximum spring deformation can also be limited (e.g. in order to achieve more comfortable operation in the use as a hand trainer) by spacers introduced between the force introduction areas of the two spring elements. In this case, the curvature of the spring elements is not completely canceled even when the maximum spring force is applied.
The two joint elements are preferably rounded, and the brackets each form a bearing in which the respectively enclosed second joint element is mounted rotatably. The first joint element of both spring elements is in each case designed as a bracket, wherein the bracket has a bend in the direction of the concave side of the spring element. In the area adjoining the spring element, the brackets have a small bend radius compared to the curvature of the spring element. The brackets preferably run out in an area that is not curved or that is only slightly curved. The area with the small bend radius forms a bearing for the other joint element. The small bend radius is preferably adapted to the rounded shape of the second joint element. The second joint element of a spring element is mounted rotatably in the first joint element or the bracket of the other spring element such that, when the muscle trainer is actuated, the joint elements of the spring elements can execute a rotational movement relative to those of the other spring element. This mutual mobility avoids or minimizes the flexural stress in the area of the joints when the muscle trainer is actuated. The second joint elements are preferably designed as rollers, of which the radius preferably corresponds to the small bend radius of the bracket.
The spring element preferably merges tangentially into the bracket. Alternatively, it is possible for the transition from the spring element to the bracket to be designed in such a way that the bracket curved in the direction of the concave side of the spring element is angled in the direction of the convex side of the spring element.
The first spring element and the second spring element preferably have an identical geometry. Two such identical spring elements in this case form the muscle trainer, wherein the first spring element and the second spring element are arranged relative to each other such that the concave sides of the spring elements face toward each other and, at the ends of the spring elements, a first joint element adjoins a second joint element of the respective other spring element. In this way, it is advantageous that no different parts have to be produced, and therefore the two spring elements are able to be produced using the same tool, for example an injection mold. The two spring elements are preferably produced as two separate parts. Two identical spring elements can be joined together by turning one of the two spring elements about the transverse axis in such a way that the brackets at least partially enclose the second joint elements.
Preferably, in each case a 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. A lateral movement is regarded here as a movement parallel to the transverse direction defined for the spring elements.
The form-fit connection is preferably provided by in each case at least one snap-in hook on the second joint element of the spring element, said snap-in hook engaging in each case in a corresponding opening or in corresponding recesses on the bracket or in the first end area of the joint element of the spring element. The snap-in hook extends from the second joint element substantially in a direction which lies in the plane enclosed by the longitudinal direction and the vertical direction, such that relative movements of the corresponding joint elements in directions parallel to the transverse direction are prevented.
The snap-in hook preferably points in the vertical direction since, by interaction with the opening in the first end area, it then not only prevents the relative movement in the transverse direction but also prevents a relative movement in the longitudinal direction.
The form-fit connection is additionally secured by the fact that a projection on the snap-in hook bears on the outer face of the other spring element. The snap-in hook is arranged and designed in such a way as to prevent, by means of the form-fit connection, both a movement of the first spring element relative to the second spring element in the transverse direction and also a movement in the longitudinal direction and in the vertical direction. Only a rotational movement about the transverse axis of the joint is possible. For this purpose, the snap-in hook is guided through the opening, and its projection engages over the outer face of the other spring element.
Viewed in the vertical direction, the second joint element preferably has an opening under the snap-in hook, such that the spring element has no undercuts in the vertical direction.
Alternatively or in addition, the wall thickness of the bracket, seen across the width of the spring element, can vary continuously, wherein the wall thickness is greatest, for example, at the center and decreases toward the side edges. The wall thickness or, in the case of a second joint element designed as a roller, the diameter of the second joint element of the spring element, seen across the width of the spring element, accordingly also has a variation, wherein the wall thickness or the diameter is at its smallest at the center and increases toward the side edges. The joint elements are here regarded as part of the spring element, such that the described variation of the wall thickness can take place at the joint elements and/or at the end areas of the spring elements.
The joints of the proposed muscle trainer securely connect the two spring elements, such that an unwanted separation of the spring elements does not take place. In preferred embodiments, relative movements of the paired joint elements are suppressed in all three spatial directions, wherein a rotational movement remains possible upon actuation of the muscle trainer. By means of this rotational movement, bending stresses upon actuation of the muscle trainer are advantageously substantially avoided in the end areas. The joints are advantageously compact and take up little room.
The muscle trainer is preferably composed of two pieces, wherein each piece comprises one of the spring elements. The first spring element and the second spring element are preferably both free of undercuts. This permits simple production of the spring elements by injection molding. Advantageously, the mold does not require movable slides, such that cost-effective production is permitted.
Printed details can preferably be provided on the muscle trainer by means of elevations or depressions.
The two spring elements are preferably produced from a thermoplastic.
The thermoplastic is preferably chosen from polyoxymethylene (POM), polybutylene terephthalate (PBT), polyamide (PA), acrylonitrile-butadiene-styrene (ABS) and polypropylene (PP).
To realize good sliding characteristics, in the case of which only low friction and no generation of noise arise during a movement of the joint elements relative to one another, in each case different materials should be used for the two spring elements, in a known manner. For example, one of the spring elements is manufactured from polyoxymethylene (POM) and the other spring element is manufactured from a thermoplastic material that differs therefrom. A disadvantage of this approach is however that the two spring elements possibly have different characteristics, in particular shrinkages.
As an alternative to this, it is possible for both spring elements to be manufactured from the same thermoplastic material, wherein a tribologically modified thermoplastic material is used. In particular, tribologically modified polyoxymethylene (POM) is suitable for this purpose. For an optimization of the tribological characteristics of the material, a silicon oil is normally added as an additive to the POM for this purpose. A suitable tribologically modified POM is available under the designation Ultraform N 2320 003 TR. In this design variant, it is preferable for both spring elements to be manufactured from the tribologically modified POM. This has the advantage that distortion or shrinkage during the manufacturing process affects both spring elements equally, such that the spring elements can be assembled to form the muscle trainer without problems and in an accurately fitting manner.
The plastic of the spring elements can be reinforced or non-reinforced, it being possible for a fiber-reinforced plastic to have a fiber content of up to 60% by weight. Suitable fibers are chosen, for example, from, glass fibers, aramid fibers, carbon fibers. The fibers can be present as short fibers, long fibers or “endless fibers”. The stiffness of the spring elements, and therefore the stiffness of the muscle trainer, can be deliberately influenced by way of the fiber content.
Moreover, the plastic can contain further additives according to requirements.
The force introduction areas of the spring elements preferably each comprise a force introduction element. The force introduction element preferably encloses the force introduction areas of a spring element.
The force introduction element, which is preferably designed a grip in the case of use as a hand trainer, can be made from a material other than the material of the spring elements. In order to achieve haptics that are acceptable for the user, a material is preferably used which is soft by comparison with the material of the spring elements. For example, the force introduction element is produced from a thermoplastic elastomer (TPE), for example a thermoplastic polyurethane (TPU). The force introduction element can be compact or foamed. For foamed force introduction elements, a polyurethane foam is preferably used.
The force introduction element preferably has a spacer on the concave side of the spring element, which spacer limits the bending of the muscle trainer.
A further aspect of the invention concerns providing a method for producing one of the described muscle trainers. To this end, a method is proposed 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 are directed toward 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 force to the spring elements,
d) snapping a second joint element into a first joint element, such that the first joint elements each at least partially enclose a second joint element of the respective other spring element,
e) terminating the force application, wherein the joint elements of the spring elements form joints.
In step a) of the method, the two spring elements are produced by injection molding. In particularly advantageous variants of the method, the two spring elements do not have any undercuts, such that the at least one injection mold used has no slides. The injection mold can therefore be produced particularly simply and cost-effectively.
Moreover, both spring elements are identical in terms of their geometry, such that they can be produced in the same cavity of the tool or in the same injection mold. The identical nature of the geometry of the two spring elements also ensures that they have the same warpage after the production process. By means of warpage occurring after the injection molding, in particular during cooling, the actual geometry of the spring element produced deviates from the desired geometry. Since the first spring element and the second spring element have an identical geometry, any warpage that occurs will influence both spring elements equally. It is therefore easily possible for the two spring elements to be arranged, according to step b) of the method, such that a first joint element and a second joint element adjoin each other at both ends of the spring elements. Spring elements that differ in geometry could warp to different extents, which would prevent the formation of the joints.
After the production of the two spring elements, the joints are not yet brought together. To insert a second joint element of the spring elements into the corresponding first joint element of the other spring element, the two spring elements, in step b), are accordingly arranged relative to each other. This can be done, for example, by turning one of the two spring elements about the transverse axis.
In step c) of the method, forces are exerted on the first spring element and on the second spring element. The forces are preferably exerted at the force introduction areas of the spring elements, wherein for example one of the spring elements can lie on a support and, by way of a ram, force is applied to the force introduction area of the other spring element. The two spring elements are thereby bent, and their curvature decreases, such that the second spring element can be inserted into the first spring element in accordance with step d). Thereafter, the application of force to the first spring element and to the second spring element is terminated (step e)). The one or more spring elements spring back to their respective starting position, whereupon a form-fit connection is established and the joints are formed. The muscle trainer is ready for use.
If the force introduction areas of the spring elements have force introduction elements, for example grips, made from a material other than that of the spring elements, then, in step a), after production of the spring elements, the latter are inserted into a further mold in order to produce the force introduction elements or, by pulling back slides, a corresponding mold for producing the force introduction elements is generated. The force introduction elements can then be injected onto the spring elements.
Alternatively, the force introduction elements can also be produced separately and then connected to the spring elements by a form-fit or force-fit engagement and/or by a cohesive fit.
A further aspect of the invention concerns the use of one of the described muscle trainers as hand trainer, arm trainer or leg trainer, with a use as hand trainer being preferred.
Various muscle trainers designed as hand trainers and each having identical geometric dimensions were produced. The thermoplastic used for the spring elements was varied in each case in order to produce hand trainers with different stiffness or different spring forces. Polyoxymethylene (POM) was used as the thermoplastic, the POM being non-reinforced in one example and being reinforced, in five other examples, with different contents of glass fibers.
The spring elements produced have a curved, elongate shape, wherein the width of the spring elements is 25 mm at the ends and 19 mm at the center of the spring elements. The length of the spring element without application of force, measured as direct connection line between the two ends, is 204 mm. The wall thickness of the material is 2.5 mm at the ends and 5 mm at the center. The curvature of the spring elements is such that, in the assembled state, the two spring elements are at a distance of 59 mm from each other at the center.
To calculate the opposing force of the spring elements during use in the muscle trainer, it was first necessary to determine the modulus of elasticity of the various plastics. To measure the modulus of elasticity of the plastic, specimens were produced and, in the tensile test as per ISO 527-2:1993, the force and the change in length were measured at a defined testing speed. The tensile tests were carried out on specimens made of polyoxymethylene (POM) with different glass fiber contents; the determined moduli of elasticity, which describe the stiffness of the specimen, are listed in Table 1. These were each determined at a testing speed of 1 mm/min.
The tensile tests show that, by addition of 5 to 25% by weight of glass fibers, the modulus of elasticity of the material can be increased from 2700 MPa for non-reinforced material to 8800 MPa for material reinforced with 25% by weight glass fiber content.
The calculation revealed that spring elements with a glass fiber content of 25% by weight were already too stiff for use as hand trainers. Therefore, spring elements for hand trainers were produced from non-reinforced material and from five materials with different glass fiber content. In each case, two identical spring elements were assembled to form a hand trainer, and the stiffness of the hand trainers produced was determined. For this purpose, a hand trainer was placed in a test apparatus in which a ram was used to exert force vertically on the force introduction area of one of the spring elements. The other spring element lay on a table, such that the hand trainer was increasingly pressed together by the exerted force. The deformation travel of the hand trainer and the exerted force were measured.
The measurement results for the five tested hand trainers are shown in
From the force-travel curves in
The stiffness of a hand trainer is defined as the gradient of the force/travel curve. On account of the slight non-linearity, the stiffness decreases slightly as the deformation travel increases.
The stiffness for the range of 15 mm to 20 mm deformation travel was evaluated in the range of the maximum measured deformation of 20 mm. The stiffness determined for the tested hand trainers is shown in Table 2.
Illustrative embodiments of the invention are shown in the figures and are explained in more detail in the following description.
In the figures:
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.
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.
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
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
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.
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
The joint of the muscle trainer 1 shown in
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.
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.
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.
The muscle trainer 1 of the first embodiment, described with reference to
In this view from above, in conjunction with the view from the front in
In the illustrative embodiment shown in
As has already been described with reference to
The second joint element 16 is designed as a roller 24 and is mounted rotatably in the bearing 20 formed by the bracket 18.
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.
In the unloaded state shown in
As has already been described with reference to
The spring element 11, 12 of the hand trainer shown in
In the embodiment shown in
The wall thickness of the spring element 11, 12 in
In contrast to the muscle trainer of the first embodiment shown in
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.
The deformation travel 48 and the associated force F are recorded during the measurement.
In the diagram in
From the force-travel curves in
1 muscle trainer
2 length
4 width
5 width at the center
6 wall thickness of the end areas
7 wall thickness at the center
8 force introduction area
11 first spring element
12 second spring element
13 first end area
14 second end area
15 first joint element
16 second joint element
18 bracket
20 bearing
22 axis
24 roller
26 snap-in hook
28 projection
30 opening
32 long opening
34 wide opening
36
36 grip
38 spacer
40 distance, unloaded
42 distance, loaded
44 ram
46 table
48 deformation travel
F force application
| Number | Date | Country | Kind |
|---|---|---|---|
| 16165512.1 | Apr 2016 | EP | regional |
| 16188354.1 | Sep 2016 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/058797 | 4/12/2017 | WO | 00 |
