Drive unit for a training device and training device having same

Abstract

The invention relates to a drive unit (4) for driving a wheel (31) of a training device (3a; 3b) by means of a tread force of a user (P) of the training device, wherein the drive unit is designed such that it translates a path, described by a human foot, during walking or running into an elliptical path (55) for the foot, wherein the drive unit has a left-hand and a right-hand L-shaped or V-shaped drive arm (9, 10), a left-hand and a right-hand roller system, which each comprise at least one roller (12), wherein the roller systems are rotatably connected to the drive arms, wherein the rollers are received to be linearly movable back and forth in guide rails (2a) of the drive unit or of a frame (2) of the training device, a coupling (50) for transferring the tread force of the user to the wheel, and a left-hand and a right-hand foot pedal (17, 18) for inputting the tread force into the drive unit. The invention furthermore relates to a training device (3a, 3b) designed as an elliptical trainer and having a drive unit (4) according to the invention.

Description

[0001] Drive unit for a training device and training device with such a

[0002] Field of the invention

[0003] The invention relates to a drive unit for driving a wheel of a training device by means of a user's pedal force and to a training device having such a drive unit, according to the respective independent claim.

[0004] background

[0005] Training equipment for physical exercise is well known and available in countless variations depending on the part of the body to be trained. One category of training equipment is aimed at training the leg muscles, among other things. There are training devices that also train fitness, for example. Such training devices can be further subdivided; some are bicycle-like and, as stationary devices, only have a rear wheel that is propelled in place using leg muscle power, and some, as mobile devices, use two wheels. A subtype of the latter are so-called elliptical trainers, which are designed as mobile devices. These usually have a rear wheel, a front wheel, a frame, a steering unit and a drive unit. They differ from conventional, bicycle-like training equipment primarily in the changed path described by the pedals during a full rotation.While the pedals on conventional bicycle-like machines follow a circular path, elliptical trainers are characterized by a modified path, which is primarily achieved through a modified drive unit. It has been found that an elliptical path is easier on the joints, as the foot and leg movement is more fluid and allows for a smoother transition between the highest and lowest pedal positions.

[0006] The drive unit of an elliptical trainer with an elliptical track, as known from W02008063499, comprises two elongated pedal platforms as drive arms, which are connected to a crank unit at the rear and attached to guide rails provided in the frame of the elliptical trainer at the front by means of rollers. Due to the circular movement of the crank unit at the rear and a linear movement of the rollers at the front in the guide rails, an elliptical path of the pedals results during use. During use, the person stands on these pedal platforms and transfers leg power to the crank unit, which transfers this power to the rear wheel for propulsion.

[0007] A solution known from W02013120126 attempts to replicate the natural path of the foot when running or jogging. This path is not an ellipse but rather a kind of teardrop shape, with the drop curved upwards. This solution explicitly avoids the elliptical path. The teardrop-shaped path used here is the result of the special U-shaped design of the drive arms. The goal here, too, is to protect the joints, but the typical path of the foot when walking is replicated.

[0008] Some disadvantages of this solution are explained below using the example of a mobile elliptical trainer with an elliptical track. On this mobile elliptical trainer, the pedal platforms are generally relatively long and bulky because the connection to the crank drive is typically located either behind or above the rear wheel. This results in a high step-on height for the user with a relatively high center of gravity, which makes riding at slow speeds and starting / stopping difficult. The long pedal platforms also require long guide rails, which in turn leads to a long wheelbase. The long wheelbase also means that only small wheels with a 20-inch diameter are usually used, making it unsuitable for off-road use. Due to the long and tall design, it is not possible to design such an elliptical trainer for a sitting position in the traditional way.A machine of this design is therefore bulky and heavy, making it difficult to transport. Furthermore, the user's high stance on the elliptical trainer makes balancing more challenging.

[0009] Description of the invention

[0010] The object of the present invention is to provide a training device that is compact, versatile and gentle on the joints.

[0011] This object is achieved in a first aspect of the invention with a drive unit for driving a wheel of a training device by means of a pedal force of a user of the training device. The drive unit is designed such that it translates a path described by the human foot when walking or running into an elliptical path for the foot. The drive unit comprises the following:

[0012] - a left and a right L-shaped or V-shaped drive arm,

[0013] - a left and a right roller system, each comprising at least one roller, wherein the left roller system is rotatably connected to the left drive arm and the right roller system to the right drive arm, each in the region of a front extremity of the respective drive arm, wherein the at least one roller of each drive arm can be accommodated in a linearly displaceable manner back and forth in at least one guide rail of the drive unit or in at least one guide rail of a frame of the training device, - a coupling with a left and a right crank for transmitting the user's pedaling power to the bike, wherein the coupling is rigidly connected to the left and right cranks at a respective crank point, wherein the left crank is rotatably connected to the left drive arm and the right crank is rotatably connected to the right drive arm, each in the region of a rear extremity of the respective drive arm,

[0014] - a left and a right foot pedal for inputting the pedal force into the drive unit, whereby the left and the right foot pedal are rotatably attached to the left and right drive arms respectively.

[0015] The object is achieved in a second aspect of the invention with a training device. The training device comprises a frame with at least one chainstay and a frame segment, wherein a front end of the chainstay is fastened to a lower end of the frame segment, a rear wheel fastened to a rear end of the chainstay, a steering unit or holding unit fastened to an upper end of the frame segment, and a drive unit according to the first aspect of the invention.

[0016] The frame segment has at least one guide rail on the left and right sides, in each of which at least one guide roller of the left or right drive arm of the drive unit can be accommodated so as to be linearly displaceable back and forth parallel to a longitudinal axis of the down tube. The coupling of the drive unit is rotatably fastened to the frame between the frame segment and the rear wheel. The training device also comprises a power transmission element, by means of which pedaling force from a user of the training device can be transmitted to the rear wheel and causes it to rotate. In some embodiments, the power transmission element is preferably a chain or a belt.

[0017] The L-shaped or V-shaped design of the drive arms, combined with the pedals being arranged to the side rather than integrated into the drive arms, makes it possible to create a drive unit that allows for a compact design of the training device, thus improving its usability both in stationary and on-road applications. The shorter wheelbase makes the training device easy to transport and can be manufactured not only in a version that requires the user to stand, as in the case of an elliptical trainer with pedals integrated into the arm, but also in a seated version.

[0018] In embodiments, the left and right roller systems of the drive unit according to the invention each comprise a lowering arm. The lowering arm is rotatably attached to the at least one roller at an upper end and rigidly attached to the respective drive arm at the lower end in the region of a front extremity thereof, such that the front extremity of the respective drive arm is always lowered relative to the at least one roller. Advantageously, this lengthens the horizontal elliptical path of the pedal without having to change the length of the cranks. The elliptical path lengthened in this way generally results in a smoother pedaling motion for the user and thus contributes to protecting the joints. It is preferred if the attachment between each lowering arm and the respective drive arm is adjustable such that the distance between the front extremity of the drive arm and the at least one roller can be changed by the user.This longer horizontal stroke of the elliptical track allows for a more optimal power flow from the user to the machine. It also allows the user to adjust the height of the pedals from the floor depending on their body size and preferences.

[0019] Alternatively, a leg of the drive arm on the roller side (described below) can serve as the lowering arm itself. This means there is no separate lowering arm, simplifying the design. However, the attachment is analogous to that described above.

[0020] In some embodiments, the attachment between each crank and the respective drive arm is adjustable such that the distance between the rear extremity of the drive arm, i.e. the respective coupling point, and the respective crank point can be changed by the user. In addition to the extension of the horizontal elliptical path resulting from the above-mentioned lowering of the front extremity of the drive arm, a lengthening of the drive arm (greater distance between the rear extremity of the drive arm and the crank point) also contributes to a longer horizontal elliptical path for the pedals. In other words, changing the length of the drive arm has the following effects: Together with the lowering and shortening of the drive arm, the elliptical path lengthens and vice versa.When the drive arm is shortened (smaller distance between the rear extremity of the drive arm and the crank point), there is an advantage with a mobile training device, namely the possibility of using a front wheel with off-road equipment such as off-road tires and a corresponding suspension fork, since the shortening creates more distance between the drive arm and the front wheel.

[0021] It is preferred if the coupling is designed as a gear for a chain drive or as a pulley for a belt drive and can be mounted on a frame of the training device. The drive unit according to the invention can therefore be easily adapted to existing frames and rear wheels. It is preferred if the coupling can be mounted in front of the wheel of the training device to be driven. In embodiments, the left and right drive arms each comprise a clutch-side leg, to which the respective left or right crank is rotatably attached, and a roller-side leg, to which the respective left or right roller system is rotatably attached. This creates the above-mentioned L-shape or V-shape of the drive arm. It is preferred if the roller-side leg is longer than the clutch-side leg.This contributes to the compactness of the training device because the guide rail can be made shorter, thus shortening the overall length of the training device. For example, the coupling-side leg and the roller-side leg can be rigidly connected to one another or formed into a single piece. To create an L-shape or V-shape, the legs are angled to one another to suit the respective shape. This design has the advantage that the two legs can be manufactured independently of one another, and the drive arm can then be adapted to different frames for different training devices and user needs by varying the connection angle. Alternatively, the coupling-side leg and the roller-side leg can be curved and merge into one another to form a single piece. This has the advantage that the drive arm is more rigid and therefore more stable.In addition, this reduces the assembly effort and the number of connections such as welding points.

[0022] In some embodiments, the left and right drive arms each have a reinforcing leg which additionally rigidly connects the coupling-side leg to the roller-side leg. The reinforcing leg thus forms a triangle with the coupling-side leg and the roller-side leg and increases the stability of the drive arm. It can be straight or curved. It can be attached to the respective free extremity of the coupling-side leg and the roller-side leg, or it can be attached at any point along one or the other or both legs. It can also be manufactured in one piece with the two legs. Alternatively, no reinforcing leg is provided, which simplifies the design.

[0023] The pedals are preferably each pivotally attached to the coupling-side leg of the associated drive arm. This has the advantage that their position closer to the rear wheel also allows the use of a seat for the training device, as the pressure surface for the pedals is essentially below the body's center of gravity. This is particularly advantageous for mobile training devices as the seat also offers an opportunity to rest on longer distances. This is not possible, for example, with the elliptical trainer mentioned at the beginning with the pedals integrated in the drive arm because the pedal surfaces are arranged towards the front wheel, and accordingly this device does not have a seat. The fact that the pedals can be rotated on the drive arm also results in better ergonomics when pedaling. Finally, the design is more compact because the pedals are mounted comparatively close to the coupling point.Alternatively, the pedals are mounted at the meeting point of the roller-side leg with the clutch-side leg.

[0024] In some versions, the position of the pedals is adjustable horizontally and vertically, which offers the user an additional degree of freedom to adapt to his body mass and preferences:

[0025] - horizontally this is achieved by adjusting the attachment point of the pedals along the longitudinal axis of the respective clutch-side leg.

[0026] - vertically this is achieved in that the drive unit further comprises an additional connecting piece between the clutch-side leg and the associated pedal. By means of these connecting pieces, an adjustment of the distance between the pedal and the clutch-side leg can be effected by the user. To implement this function it is particularly preferred if the connecting piece is a bracket fastened to the clutch-side leg and running essentially parallel to this, with fastening means for the pedal. The bracket is preferably fastened to both ends of the clutch-side leg, although it can also be fastened at other points along the clutch-side leg. However, it could also be formed in one piece as part of the clutch-side reinforcing leg.Alternatively, a vertical connecting piece can be used, which can be attached to only one point on the coupling-side leg. Although this solution is simpler, it offers reduced stability compared to the bracket. Alternatively, no adjustment of the pedal attachment point is provided, which simplifies the design. It has been shown that the adjustment options described above on the extremities of the drive arm (roller-side leg and coupling-side leg) are sufficient to achieve a good adaptation to the user's body mass.

[0027] In some embodiments, the roller systems each have at least one guide roller and at least one counter roller, which are offset from one another in such a way that each roller can be accommodated in its own guide rail of the frame of the training device in a linearly displaceable manner back and forth. The guide roller on the drive arm takes up the main weight of the user and slides back and forth on the guide rail. The counter roller absorbs the counter forces and serves to stabilize the drive arm and prevents the drive arm from slipping off the guide rail. It is preferred if the guide roller and the counter roller of a roller system have different diameters, with the diameter of the guide roller being particularly preferably larger than the diameter of the counter roller, since the guide roller bears the main weight. This saves material and the guide rail can be made smaller.Particularly preferably, two guide rollers are provided, and the left and right roller systems each further comprise at least one reciprocally displaceable safety roller, which is arranged relative to a position of the guide roller(s) in such a way that it prevents the roller system from jumping out or being accidentally removed from the guide rail. Particularly preferably, the safety roller is provided on an opposite side of the guide rail relative to the guide roller.

[0028] The preferred embodiments of the training device according to the invention with a drive unit according to one or more of the features described above are explained in the context of the description of the figures.

[0029] Short description of the drawings

[0030] Further embodiments, advantages, and applications of the invention will become apparent from the dependent claims and the following description with reference to the figures. In these figures:

[0031] Fig. 1 the typical path of the human foot when walking,

[0032] Fig. 2 the typical path of the foot when cycling,

[0033] Fig. 3 shows the path of the foot in the present invention,

[0034] Fig. 4 is a side view of a mobile training device according to the invention in a first position of the pedals,

[0035] Fig. 5 is a side view of the mobile training device according to Fig. 4 in a second position of the pedals,

[0036] Fig. 6 is a side view of a stationary training device according to the invention,

[0037] Fig. 7 is a side view of a drive unit according to the invention,

[0038] Fig. 8-11, three embodiments of the drive arm of the drive unit from Fig. 7, and Fig. 12 a clutch with cranks of the drive unit according to Fig. 7,

[0039] Fig. 13 is a perspective view of a preferred embodiment of the drive unit according to the invention on a guide rail,

[0040] Fig. 14 is a side view of the embodiment of Fig. 13,

[0041] Fig. 15 is a cross-sectional view of a roller system of the drive unit of Fig. 13 on the guide rail, and

[0042] Fig. 16 a perspective view of the roller system from Fig. 15 without guide rail.

[0043] Ways to implement the invention

[0044] Positional terms such as left and right or up and down refer to the usual meaning in connection with a bicycle.

[0045] Terms related to the elliptical orbit refer to the mathematical definitions of an ellipse.

[0046] The term "path" refers to a path actually described by the pedal, e.g., the contour of an ellipse. On the other hand, the term "path" refers to the horizontal or vertical projection of the path or, more generally, to a linear path.

[0047] In the present context, a clutch is defined only as a drive-side part, e.g. as a rack / chainring of the drive unit, in order to distinguish between the drive unit assembly and the rest of the training device, which includes the counterpart (pinion / hub) arranged on the rear wheel.

[0048] In the context of the present invention, "displaceable" in relation to rollers means that these roll back and forth in the guide groove and in the process the bearing of the respective roller experiences a linear displacement. Fig. 1 shows a schematic representation of the typical path that a human foot describes when walking. Here, x denotes the walking direction and y the lifting height of the foot in relation to the heel. The leg position of the right leg of the person P is shown schematically and is intended to approximately illustrate the position, in particular in relation to a ground center line b between the feet. The movement or the path begins with a so-called initial swing IS, in which the leg is lifted for the step. This is followed by a middle swing MS in which the leg is moved forwards until the final swing TS. Immediately after this follows a so-called final swing TS.Heel strike HS after which the foot is on the ground for the duration of the movements already described for the other foot. This is followed by a so-called toe push-off TO while the other foot now has contact with the ground, followed by a so-called forward swing PS while the other foot is completely on the ground. During the forward swing the foot is lifted until it reaches the initial swing position, after which the process is repeated. The path drawn in Fig. 1 is referred to in the present context as an upwardly curved drop-like path and was already mentioned above in the context of a prior art document.

[0049] Fig. 2 schematically shows the typical path described by a human foot while riding a bicycle. This path is a simple circular path determined by the bicycle's gear, also called the chainring.

[0050] Fig. 3 shows an elliptical path that a human foot describes when using the training device according to the invention. The training device is also referred to below as an elliptical trainer. It is therefore characterized in that a pedal describes an elliptical path during one complete pedal rotation, in which in the case of the present invention (see Fig. 5) a front vertex of the ellipse is higher than a rear vertex of the ellipse (black dots in the figure). It is generally preferred and the dimensions of the elements of the drive arm and the guide rail are selected such that the main axis of the ellipse, which connects the two shown vertices, is longer than twice the length of the cranks and / or longer than a clutch-side leg of the drive arm. The main axis of the ellipse corresponds to a linear path that the drive arm covers on the guide rail during one complete pedal rotation.This allows for an ergonomic elliptical movement despite the smallest space.

[0051] From a comparison of Fig. 1 to 3 it can easily be deduced that the load on the feet or rather the ankle and leg joints is different due to the different paths. In the gait pattern from Fig. 1 it is generally known that this path is a natural path for the feet, however the load can vary greatly due to various misalignments of the feet, etc. and is therefore not always the most joint-friendly alternative when training. In the circular path from Fig. 2 the "fall height" between the highest point of the path and the lowest point of the path is very great and has a correspondingly high braking force during the transition between the highest position and the lowest position, which can lead to a high load on the knees. The elliptical path from Fig.3 creates a smoother transition between the top and bottom positions, resulting in a smaller force gradient, which is gentler on the joints. This aspect is particularly important during training.

[0052] Fig. 4 and Fig. 5 show a side view of a mobile training device, wherein Fig. 4 shows a first position of the pedals and Fig. 5 a second position of the pedals. The first position corresponds to the position in the frontmost position of the right pedal 18 and the second position corresponds to an intermediate position of the pedals. Furthermore, Fig. 4 shows a saddle 53 to illustrate this option by way of example. The saddle can also be provided for a stationary training device.

[0053] The training device 3a comprises a frame 1 with a frame segment 2 and two chainstays 2b to the left and right of a rear wheel 31 fastened to both chainstays. A front end of the chainstays 2b is fastened to a lower end of the frame segment 2. Depending on the design of the mobile training device 3a, the frame segment 2 can correspond, for example, to a down tube or a top tube of the frame, the designations corresponding to technical terms for a bicycle. In the present case, the chainstays are fastened to the lower end of the frame segment via a cross brace. Direct attachment is of course also possible if the frame is designed accordingly, e.g. in the form of a monocoque frame.

[0054] Furthermore, a steering unit or holding unit is provided which is fastened to an upper end of the frame segment 2 and which comprises a handlebar 40 and a handlebar 41 which are connected to a front wheel 30.

[0055] The training device further comprises a drive unit 4 (Fig. 7). The drive unit 4 comprises a coupling 50 to which a left and a right crank 20, 21 are fastened at a crank point Z (Fig. 7). A left and a right drive arm 9, 10 are each fastened to the cranks 20, 21 at a coupling point 16, 19. Each drive arm has on its front extremity a guide roller 12 and a counter roller 13 fastened via a lowering arm 8 in a lowering arm fastening point 11. Each roller is held in its own associated guide rail 2a and can be moved back and forth linearly along the longitudinal axis of the frame segment which runs diagonally upwards towards the front. Basically, for all embodiments of the invention, all existing rollers move back and forth in associated guide grooves, which is described using the example of the embodiment in Fig. 13-16.The drive arms each have a clutch-side leg 22 and a roller-side leg 23, which in this embodiment are one-piece and L-shaped. Pedals 17, 18 are provided on the left and right, each of which is attached to the associated drive arm at pedal attachment points 14 or 15. The elliptical path 55 described by the pedals is shown in Fig. 5 by the dashed ellipse. Details of the individual elements of the drive unit 4 for the specific embodiments shown in the figures are described in the context of Figs. 7-11.

[0056] The frame segment 2 therefore has two guide rails 2a on the left and right sides, in each of which a guide roller 12 and a counter roller 13 of the left or right drive arm 3b of the drive unit are accommodated so as to be linearly displaceable back and forth parallel to a longitudinal axis of the frame segment 2. However, only one guide rail could be provided for the guide roller per side of the frame segment, which is described in detail in connection with the embodiment of Figs. 13-16. In one variant of the invention, the at least one guide rail 2a is part of the drive unit 4. In this case, the frame segment 2 of the training device is designed such that the guide rail 2a can be fastened thereto, so that the frame segment 2 and the guide rail 2a form a fixed structural unit. Appropriate fastening means are provided for this purpose.Advantageously, the drive unit can thus be adapted to a conventional frame segment 2 with less effort. In another variant of the invention, the at least one guide rail 2a is part of the training device and not part of the drive unit 4. In this case, the guide rail could either be permanently mounted on the frame segment 2 or it could be formed in the frame itself, so that, for example, guide grooves for the rollers of the drive unit are formed in the frame segment itself. Advantageously, this eliminates any connecting devices and the construction of the frame 1 with the guide rails is more stable.

[0057] The clutch 50 of the drive unit 4, designed as a gear, is rotatably mounted on the frame 1 between the frame segment 2 and the rear wheel 31. To drive the rear wheel 31, it is connected to a pinion 51 and a hub of the rear wheel via a chain 52 as a power transmission element. Instead of a chain drive, a belt drive could also be provided. With this design, the pedaling force of the user of the training device is transferred to the rear wheel, causing it to rotate.

[0058] Fig. 6 shows a side view of a stationary training device 3b. This figure shows a further third position of the pedals, in which the right pedal 18 is in the rearmost position and which also applies to the mobile training device. In other words, the rollers 12, 13 describe a linear movement between the uppermost extremity of the guide rails (Fig. 4) and the lowermost extremity of the guide rails (Fig. 6). The stationary training device 3b differs from the mobile training device in that it does not have a front wheel. Instead, a support device for the floor is provided. Furthermore, no steering unit is provided, but merely a holding unit with a support rod and a holding rod (not shown) for supporting the user's hands. Finally, a holding device 6 is provided for the rear wheel, which supports it raised from the ground so that the rear wheel can rotate on the spot without contact with the ground.Fig. 7 shows a side view of a drive unit 4 with the elements already described. This figure clearly shows that the drive unit has numerous adjustment options. These are advantageously designed to offer the user the optimal setting for their specific preferences and body mass. The drive unit shown here represents the version without its own guide rails. In this case, the guide rails are part of the training device.

[0059] A first possibility is to adjust the coupling point 16, 19 to adapt the pedal length. Throughout the document, the holes in the drive arm have been marked 16 and the holes in the cranks 19, where 16 / 19 in the figures is intended to illustrate that one hole in each of the two elements contributes to the connection. A second possibility is to adjust the pedal height by selecting either pedal attachment points 15 on the coupling-side leg of the drive arm or pedal attachment points 14 on the reinforcement arm 5 (bracket). The pedal position can also be adjusted horizontally by selecting one of the various attachment points on the respective leg. Finally, the lowering height of the drive arm 8 can be adjusted by selecting one of the lowering arm attachment points 11.It should be noted that the lowering arm 8 is optional and, although it is included in the delivery, can be attached and removed at any time. The various stages of lowering the drive arm using the lowering arm 8 serve to adjust the height for different body sizes and also for adjustment on steep terrain for more ground clearance. In addition, the elliptical travel of the foot pedal is extended, which is shown in Fig. 12 using an example.

[0060] As already mentioned, the legs 22, 23 of the drive arms in the embodiments shown have an L-shape, which is illustrated by the 90° angle in Fig. 7. Other angles, in which the legs form a V-shape, are also possible.

[0061] Fig. 8-10 show, by way of example, three different embodiments of a right-hand drive arm of the drive unit 4 from Fig. 7. As mentioned, a guide roller 12 and a counter roller 13 can be used. The counter roller is offset inwards towards the frame segment, as can be seen from the figures. It can be offset inwards on the same axis as the guide roller or, as shown in the figures, offset inwards on its own axis. The frame segment accordingly has two guide rails on the left and right sides, with at least one guide roller of the left or right drive arm of the drive unit being able to be moved back and forth in a linear manner parallel to a longitudinal axis of the frame segment, and at least one counter roller of the left or right drive arm of the drive unit being able to be moved axially in relation to the guide roller in the other guide rail.of the right drive arm of the drive unit can be accommodated so as to be linearly displaceable back and forth parallel to a longitudinal axis of the frame segment. Figs. 8 and 10 show such a configuration, while Fig. 9 shows a further variant in which two guide rollers and a counter roller are provided. The two guide rollers 12 run in the same guide rail.

[0062] It is of course also possible to use just one or more guide rollers and no counter roller. In this case, to prevent the guide roller from slipping off the guide rail, the guide rail could, for example, be designed as a U-profile, so that the outer U-leg prevents this. However, a safety roller is preferably provided, which is described as an example in connection with the embodiment according to Fig. 13-16 and is intended to apply to all embodiments. The rollers are preferably made of polyoxymethylene (POM), rubber or polyurethane with or without a nylon core. Different Shore hardnesses can be used, depending on the weight of the user. Rubber hardnesses are known and will not be described further here.Polyoxymethylene is particularly preferred because it offers high mechanical strength and rigidity, but is easy to process, allowing the rollers to be milled to size. In contrast, PU rollers, nylon rollers, etc., require complex manufacturing processes.

[0063] Figs. 8-10 also show various exemplary embodiments of the reinforcing leg 7, which can be straight (Fig. 10) or curved (Figs. 8, 9). Furthermore, Figs. 8, 10 show drive arms with coupling-side leg 22 and roller-side leg 23 that form an L-shape, while in Fig. 9 they form a V-shape. Furthermore, in the embodiment of Fig. 8, a lowering arm 8 is provided, whereas in the embodiments of Figs. 9 and 10, no such arm is provided.

[0064] Fig. 11 shows another variant of the roller arrangement. This version features two counter rollers 13 and a guide roller 12 positioned centrally above the two counter rollers and vertically offset inward. The three rollers are attached to the lowering arm 8. This distributes the resulting torsional forces across two levels.

[0065] Of course, features of the embodiments shown in Fig. 8-11 can be combined within the scope of what is technically reasonable.

[0066] Fig. 12 shows a clutch with cranks 20, 21 of the drive unit according to Fig. 7. The cranks are attached to the chainring at crank point Z. The coupling of the cranks to the respective clutch-side drive arm can be varied at the coupling points 16, 19, the number of which can of course also be greater than shown. In the embodiment according to this figure, adjustment at the crank is also possible by providing several holes 19 in the crank, in contrast to the embodiment according to Fig. 7, in which only one hole is provided in the crank. For example, the distance between the coupling points 16, 19 and the crank point Z can be varied within a range between 20 cm and 25 cm. The closer the clutch-side leg is attached to the crank point Z, the "shorter" it becomes, i.e. the lever up to point Z becomes shorter.This means that the distance between the roller side arm and the front wheel is greater (in the mobile training device variant). Conversely, the clutch side arm becomes longer if it is attached further away from point Z. This means that the distance between the roller side arm and the front wheel is smaller (in the mobile training device variant). This can result in an extension of approx. 5-10%. If the length of the clutch side arm is, for example, 46 cm and the crank length is 25 cm, shortening the clutch side arm by 6 cm from 46 cm to 40 cm and lowering the front extremity of the roller side arm by 10 cm will lengthen the pedal travel on the elliptical track by 5-10%. This type of shortening is advantageous for taller users.

[0067] In the previous embodiments, the coupling-side leg 22 was longer than the roller-side leg 23. As mentioned at the beginning, however, it is preferred if the roller-side leg is longer than the coupling-side leg, which is realized in the following embodiment. This preferred length ratio could also be applied to the previous embodiments, and vice versa. To do so, only the preferred angle of 90° between the two legs would have to be changed.

[0068] Fig. 13 shows a perspective view of a preferred embodiment of the drive unit according to the invention on a guide rail, and Fig. 14 shows a side view of the embodiment from Fig. 13. The statements regarding the previous embodiments of the drive unit also apply to the embodiment described below, except for the features explicitly explained below.

[0069] In this embodiment, the left and right roller systems each have two guide rollers 12, which are both accommodated in a common first guide groove 12a of the guide rail so that they can move back and forth in a linear manner. The counter roller 13 is accommodated in a second guide groove 13a so that it can move back and forth in a linear manner. Furthermore, a safety roller 60 is provided for each roller system and can be accommodated in a third guide groove 60a of the guide rail so that it can move back and forth. It is arranged with respect to a position of the guide rollers in such a way that it prevents the roller system from jumping out or being accidentally removed from the guide rail. This is particularly advantageous in the mobile version of the training device with the drive unit in order to ensure that, for example, in the event of a pothole in the road, the roller system does not jump out of the guide rail.

[0070] Another difference, e.g. compared to Fig. 7, is that the drive arm is simplified here. For example, there is only a single pedal attachment point 15 and no reinforcement leg. It has been shown that the lowering arm attachment points 11 and the coupling points 16, 19 are entirely sufficient for adaptation to different users. With reference to Fig. 3, the adjustment of the lowering arm attachment point 11 changes the height of the ellipse, with the point 11 closest to the free end of the roller-side leg corresponding to the deepest lowering of the drive arm and the greatest height H of the ellipse. This adjustment option allows adaptation to the size of the user. The adjustment mainly changes the "thickness", i.e. the height H of the ellipse in relation to the y-axis. Lowering also results in a slight rotation of the ellipse forwards while the coupling point 16 / 19 remains unchanged.The lowering is particularly advantageous for taller users. The adjustment of the coupling point 16 / 19 results in an adaptation of the ellipse length L (Fig. 3) and thus of the stride length, whereby the attachment point which is closest to the crank point Z corresponds to the shortest stride length. It should be noted that for all embodiments of the drive unit according to the invention, only exactly one hole 19 / 16 can be provided in the crank 20 and / or the coupling-side leg 22. In particular, only a single coupling point 16 / 19 can be provided without any adjustment options. In this case, for example, cranks of different lengths can be provided depending on the body size or body size ratio of different users.

[0071] A further simplification is that in this embodiment no separate lowering arm is provided, but the roller-side leg 23 of the drive arm is at the same time the lowering arm and includes the lowering arm fastening points.

[0072] Fig. 15 shows a cross-sectional view of a roller system of the drive unit from Fig. 13 on the guide rail and Fig. 16 shows a perspective view of the roller system from Fig. 15 without the guide rail.

[0073] A preferred position of the above-described safety roller relative to the guide rollers is best visible in Fig. 15. It is provided on an opposite side of the guide rail relative to the guide roller. In this case, the guide rollers are arranged on the top side of the guide rail, and the safety roller is arranged on the bottom side of the guide rail. Other configurations are also conceivable.

[0074] All rollers are preferably carried by a common carrier body 61. Fig. 16 shows a preferred embodiment of the carrier body, which comprises a roller bearing 61c with a bolt 61a. The bolt is used to fasten the lowering arm or the roller-side leg of the drive arm at point 11, wherein, as described above, the lowering arm or the roller-side leg of the drive arm has a plurality of holes which can be freely selected by the user for fastening the roller system. It is preferred if the counter-roller 13 is mounted directly in the carrier body 61, which reduces the dimensions of the carrier body 61. In contrast, the guide rollers and the safety roller are each carried by an arm 61b of the roller bearing (double arm). In contrast to the arrangement according to Fig.11, which shows the guide roller 12 on the lowering arm and the counter rollers 13 on a cross-section attached to it, in this embodiment the support body is made of a single piece, preferably cast in one piece, which increases stability and durability. The roller bearing, which bears the entire load, is arranged in the support body.

[0075] As best seen in Fig. 15, the guide rollers 12 are preferably inclined relative to the horizontal towards the guide rail. Preferably, a roller axis xl of the guide roller forms a first angle α to the horizontal, as shown in the figure. This angle is preferably between 25° and 55° and most preferably it is 40°. In general, it can be said in this context that the roller sizes, the shape of the guide rail and the angle α are selected such that the most even distribution of forces on the guide rail is achieved. Simulations, for example, have shown that a vertical arrangement of the guide roller on the guide rail results in increased wear of the guide roller. Therefore, an angle α of 0° is preferably excluded. The angle range for α specified above has proven to be advantageous in this regard.The provision of two guide rollers also contributes to increased stability and reduced wear on each guide roller. However, only one counter roller and one safety roller are preferably provided, as these do not bear the main load of the user. However, multiple safety rollers and / or counter rollers could also be provided.

[0076] It is further preferred in this embodiment (as shown in Fig. 15) if the roller axis x2 of the safety roller forms a second angle a2 between 25° and 55° with the horizontal, with the second angle most preferably being 40°. In this document, the term "roller axis" is generally understood to mean the rotational axis of the roller.

[0077] For each carrier body, the respective second angle a2 of the securing roller is preferably equal in amount to the respective first angle al of the guide roller and, with respect to the orientation, it mirrors the angle al on the horizontal.

[0078] The guide rollers take on the main load, which is transferred to the roller bearing. If the force from pedaling was introduced directly under the guide rollers, there is no moment that needs to be supported and the ideal alignment would be vertical. The further outwards the force from pedaling is introduced, the greater the moment and the flatter the angle al of the guide rollers. The guide rollers still carry the complete vertical force from pedaling. However, there is also a horizontal force for moment support and this must be balanced out with the counter roller. This means: Pedal force further out -> angle of the guide rollers flatter (roller axis becomes steeper, angle al becomes larger). Pedal force further in -> angle of the guide rollers steeper (roller axis becomes flatter, angle al becomes smaller). In addition, the relative position of the counter roller to the guide roller also influences the angle.Put simply, if the distance between the rollers is greater, the horizontal force on the guide rollers becomes smaller and thus the angle steeper. This involves a compromise between the compactness of the roller system and the magnitude of the loads on the rollers. The counter roller can only absorb horizontal forces. Vertical forces would cause it to slip along the surface. Lateral forces are possible on the guide rollers and the safety roller.

[0079] The geometric arrangement and alignment of the guide rails in the frame, the positioning of the crank drive, and the flexible drive arms, which are designed to allow for flexible adjustment of the depth of the lowering, the length of the drive arm, and the pedal attachment, enable the installation of shorter guide rails, drive arms, and cranks. Nevertheless, an optimally long horizontal elliptical path of the foot pedal is achieved, thus enabling optimal power flow for the user.

[0080] The advantage of incorporating the drive unit into a mobile elliptical trainer is increased compactness, easy transport, individual adjustment to different body sizes, and the possibility of use both on and off-road. Furthermore, this concept can be used for both standing and seated exercise.

[0081] While preferred embodiments of the invention are described in this application, it should be clearly understood that the invention is not limited thereto and may be embodied in other ways within the scope of the following claims. Terms used in the description such as "preferred," "particularly," "advantageous," etc., refer only to optional and exemplary embodiments. List of reference symbols:

[0082] 1 = frame

[0083] 2 = frame segment

[0084] 2a = guide rail

[0085] 3a = mobile training device

[0086] 3b = stationary training device

[0087] 4 = drive unit

[0088] 5 = bracket

[0089] 6 = Holding device for the rear wheel

[0090] 7 = Reinforcing leg

[0091] 8 = lowering arm

[0092] 9 = left drive arm

[0093] 10 = right drive arm

[0094] 11 = Lowering arm attachment point

[0095] 12 = leadership role

[0096] 12a = first guide groove

[0097] 13 = Counter roller

[0098] 13a = second guide groove

[0099] 14 = Pedal attachment points on reinforcement leg

[0100] 15 = Pedal attachment point ( e ) on drive arm

[0101] 16 / 19= coupling points

[0102] 17 / 18 = left / right pedal

[0103] 20 / 21= Left / right crank

[0104] 22 = coupling-side leg of the drive arm

[0105] 23 = roller-side leg of the drive arm

[0106] 30 = front wheel

[0107] 31 = rear wheel

[0108] 40 = Steering rod / support rod

[0109] 41 = Handlebar / Grip bar

[0110] 50 = clutch

[0111] 51 = Translation

[0112] 52 = chain or toothed belt

[0113] 55 = Ellipse of the pedal track

[0114] 60 = Safety roll

[0115] 60a = third guide groove

[0116] 61 = carrier body

[0117] 61a = Bolt

[0118] 61b = arms of the support body

[0119] 61c = roller bearing

[0120] IS = initial swing

[0121] MS = middle swing TS = final swing

[0122] HS = heel strike

[0123] TO = toe push-off

[0124] PS = foreswing b = ground center line

[0125] P = Person / User

[0126] Z = crank point

[0127] 53 = saddle al = first angle a2 = second angle

[0128] L = ellipse length

[0129] H = ellipse height

Claims

Patent claims 1. Drive unit (4) for driving a wheel (31) of a training device (3a; 3b) by means of a pedal force of a user (P) of the training device, wherein the drive unit is designed such that it translates a path described by the human foot when walking or running into an elliptical path (55) for the foot, wherein the drive unit comprises the following: - a left and a right L-shaped or V-shaped drive arm (9, 10), - a left and a right roller system, each comprising at least one roller (12), wherein the left roller system is rotatably connected to the left drive arm and the right roller system is rotatably connected to the right drive arm in the region of a front extremity of the respective drive arm, wherein the at least one roller of each drive arm is linearly displaceable back and forth in at least one guide rail (2a) of the drive unit or in at least one guide rail of a frame (2) of the training device, - a clutch (50) with a left and a right crank (20, 21) for transmitting the pedaling force of the user to the wheel, wherein the clutch is rigidly connected to the left and the right crank at a respective crank point (Z), wherein the left crank is rotatably connected to the left drive arm and the right crank is rotatably connected to the right drive arm, each in the region of a rear extremity of the respective drive arm, - a left and a right foot pedal (17, 18) for inputting the pedaling force into the drive unit, wherein the left and right foot pedals are rotatably attached to the left and right drive arms, respectively.

2. Drive unit according to claim 1, wherein the left and right roller systems each comprise a lowering arm (8), wherein the lowering arm is rotatably fastened at an upper end to the at least one roller and is rigidly fastened to the respective drive arm at the lower end in the region of a front extremity thereof, or wherein the lowering arm is formed by a front extremity of the respective drive arm itself and is rotatably fastened at an upper end to the at least one roller, so that the front extremity of the respective drive arm is always lowered relative to the at least one roller.

3. Drive unit according to claim 2, wherein the attachment between each lowering arm and the respective drive arm is adjustable such that a distance between the front extremity of the drive arm and the at least one roller can be changed by the user.

4. Drive unit according to one of the preceding claims, wherein the fastening between each crank and the respective drive arm is adjustable such that a distance between the crank point (Z) and the respective coupling point (16; 19) can be changed by the user.

5. Drive unit according to one of the preceding claims, wherein the coupling is designed as a gear for a chain drive or as a pulley for a belt drive and is mountable on a frame of the training device, in particular in front of the wheel to be driven of the training device can be mounted.

6. Drive unit according to one of the preceding claims, wherein the left and right drive arms each comprise a coupling-side leg (22), to which the respective left or right crank is rotatably fastened, and comprise a roller-side leg (23) to which the respective left or right roller system is rotatably fastened, in particular wherein the roller-side leg is longer than the coupling-side leg, wherein either the coupling-side leg and the roller-side leg are rigidly connected to one another or are in one piece and are angled to one another, or the coupling-side leg and the roller-side leg are in one piece and merge into one another in a curved manner.

7. Drive unit according to claim 6, wherein the pedals are each rotatably attached to the coupling-side leg of the associated drive arm, in particular wherein a position of the pedals along the longitudinal axis of the respective coupling-side leg is adjustable by the user.

8. Drive unit according to one of the preceding claims, wherein the left and the right roller system each have at least one guide roller (12) and at least one counter roller (13), which are offset from one another in such a way that the guide roller (12) can be received in a first guide groove (12a) of the guide rail and the counter roller (13) can be received in a second guide groove (13a) in a linearly displaceable back and forth, in particular wherein the guide roller and the counter roller of the roller systems have different diameters, wherein in particular the diameter of the guide roller is larger than the diameter of the counter roller. 9 . Drive unit according to one of the preceding claims, wherein the left and right roller systems each have at least one in a third guide groove (60a) of the guide rail comprise a safety roller (60) which can be accommodated in a reciprocating manner and which is arranged with respect to a position of the guide roller in such a way that it prevents the roller system from jumping out or being accidentally removed from the guide rail, in particular wherein the safety roller is provided on an opposite side of the guide rail with respect to the guide roller.

10. Drive unit according to claim 8 and 9, wherein the guide roller is inclined relative to the horizontal towards the guide rail, wherein preferably a roller axis (xl) of the guide roller forms a first angle (al) between 25° and 55°, most preferably a first angle of 40°, with the horizontal, wherein a roller axis (x2) of the safety roller forms a second angle (a2) between 25° and 55°, most preferably a second angle of 40°, with the horizontal, in particular wherein the first angle and the second angle are equal in amount and are mirrored to one another with respect to the horizontal.

11. Training device (3a, 3b) comprising a frame (1) with at least one chain stay and a frame segment (2), wherein a front end of the chain stay (2a, 2b) is fastened to a lower end of the frame segment, a rear wheel (31) fastened to a rear end of the chain stay, a steering unit (40, 41) or holding unit fastened to an upper end of the frame segment, and a drive unit (4) according to one of the preceding claims, wherein the frame segment has at least one guide rail (2a) on the left and right sides, in each of which the at least one guide roller (12) of the left and right drive arms of the drive unit can be accommodated in a linearly displaceable manner back and forth parallel to a longitudinal axis of the frame segment, wherein the coupling (50) of the drive unit is rotatably fastened to the frame between the frame segment and the rear wheel, further comprising a force transmission element, in particular a chain (52) or a belt, by means of which a pedal force of a user of the training device can be transmitted to the rear wheel and causes it to rotate.

12. Training device according to claim 11, wherein the training device (3a) is mobile and further comprises a front wheel (30) which is steerable with the steering unit, or wherein the training device (3b) is stationary and comprises the holding unit for supporting the hands of the user, and further comprises a holding device (6) for the rear wheel so that it can rotate without contact with the ground.

13. Training device according to one of claims 11 or 12, wherein the length of the coupling-side leg is smaller than the length of the at least one guide rail.

14. Training device according to one of claims 11 to 13, wherein the coupling of the drive unit is arranged on the frame of the training device in front of the rear wheel of the training device to be driven and above the axis of rotation of the rear wheel.

15. Training device according to one of claims 11 to 14, wherein, in the case that the at least one guide rail is part of the drive unit, the frame segment is designed such that the guide rail can be attached to it so that the frame segment and the guide rail form a solid structural unit.

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