Abstract:
The invention relates to a fitness device ( 1 ) that can be used in a mobile or stationary manner, comprising: a frame ( 4 ) on which two front wheels ( 6 ) and one rear wheel ( 5 ) are disposed, a drive device on each side of the frame ( 4 ), each made up of an arm drive rod ( 2 ) joined to a leg drive rod ( 3 ) by a hinge, wherein the leg drive rod ( 3 ) transfers a torque via a ring gear ( 10 ) and a chain to the rear wheel ( 5 ), a steering device ( 7 ) for steering the fitness device ( 1 ) in mobile use by means of tilting the frame ( 4 ), and a tilting/steering damper formed by damping elements ( 9 ) and disposed between the front wheels ( 6 ) and the frame ( 4 ).

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to a mobile fitness device comprising a frame on which two front wheels and a rear wheel are disposed. Furthermore, the invention relates to a steering assembly of such a fitness device. 
       BRIEF DISCUSSION OF RELATED ART 
       [0002]    So-called crosstrainers or elliptical trainers are known from the prior art. Due to the simultaneous use of arms and legs, training devices of that type simulate an ergonomic walking movement similar to the sequence of movements of Nordic walking. A flywheel, which has a changing resistance because of a brake device, for example, is driven to rotate by the sequence of movements in stationary crosstrainers. Because stationary training devices must have a high degree of stability, they have a large own weight. Thus, transporting such crosstrainers is difficult. For that reason, crosstrainers are configured for training in enclosed spaces. 
         [0003]    Furthermore, a training device that can be operated with the arms and legs similar to a crosstrainer is apparent from DE 203 19 128 U1. Unlike stationary crosstrainers, the training device is configured as a vehicle. Steering generally takes place by means of movable, preferably rotatable or pivotable handles that drive the steering via a steering system, for example via Bowden cables. Steering systems are potentially subject to the risk that the two steering handles can be actuated in the respectively opposite direction, which neutralizes a steering movement.=&gt;see A1. Furthermore, mobile crosstrainers are known that can be steered by means of a tilting steering mechanism. These are disadvantageous in that a tilting movement is brought about very easily, which leads to an unstable driving behavior. 
       BRIEF SUMMARY 
       [0004]    The invention provides a mobile fitness device in which the mobile use or driving behavior is improved over the known mobile fitness devices. 
         [0005]    Individual features of the inventive embodiments described herein are not limited thereto but may be combined with other features to constitute other embodiments. 
         [0006]    The mobile fitness device according to the invention substantially comprises the following features:
       a frame on which two front wheels and a rear wheel are disposed,   one driving mechanism, respectively, on both sides of the frame, each comprising an arm drive rod hinged to a leg drive rod, wherein the leg drive rods transfer a torque to the rear wheel via a gear unit,   a steering assembly for steering the fitness device by tilting the frame,   a tilting/steering damping system formed by damping elements which is disposed between the front wheels and the frame.       
 
         [0011]    The error-free steering enabled by the steering assembly is particularly advantageous. A weight shift causes the frame to tilt, whereby the steering assembly is moved in such a way that a steering movement of at least the front wheels in the direction of the weight shift takes place. 
         [0012]    The training device has two driving mechanisms comprising two hinged arm drive rods and leg drive rods. The arm drive rods are configured in such a way that they can be grasped with the hands and a driving movement is generated by the movement of the arms and/or the upper body. The leg drive rods are configured in such a way that a user of the fitness device is able to stand on them and applies a force on the drive by moving the legs. Preferably, the leg drive rods comprise treads for the feet of the user, but pedals are also conceivable. The drive is subjected to a load and driven by a preferably smooth and ergonomic sequence of movements of the arms and legs. Furthermore, it has proved to be particularly gentle on the joints to carry out circular movements, as are demanded by the proposed fitness device. 
         [0013]    Preferably, the distance of the treads from one another is selected in such a way that a particularly ergonomic sequence of movements is ensured. For example, the clear distance of the treads is no greater than 30 centimeters. In a preferred embodiment, a distance of the treads and/or an angle of the longitudinal axes of the treads can be adjusted relative to one another. 
         [0014]    The driving mechanisms are disposed on a frame which, for example, comprises longitudinal tubes which in turn are connected to two front wheels and a rear wheel. The two front wheels are preferably interconnected by a front axle. In another preferred embodiment, wheel suspensions, which are preferably configured to be movable, are disposed on the front axle. It is provided in another embodiment that the front axle is hinged to the frame. The frame, which, for example in the case of straight driving, is vertical to the front axle, can be tilted out of the vertical plane in this manner. In the case of straight driving or in an unloaded rest position of the fitness device, the frame is located in a vertical plane. The vertical plane extends along the longitudinal axis of the frame. Furthermore, the force vector of gravitation is in the vertical plane. Preferably, a horizontal plane defined by the contact points of the wheels is disposed perpendicular to the vertical plane. Moreover, the front axle is preferably disposed in a horizontal plane. 
         [0015]    A steering movement of the front wheels is enforced by means of the steering assembly by tilting the frame. 
         [0016]    Similar fitness devices are apparent from WO 2008/132191 A1 by the same applicant, to which reference is made in their entirety within the context of this disclosure. 
         [0017]    One difference to the fitness device proposed in WO 2008/132191 A1 is that the present invention comprises a tilting and/or steering damping system formed by damping elements which is disposed between the front wheels and the frame. Pendulum movements, which are in particular triggered by a movement of the user&#39;s upper body, can be effectively dampened by means of the tilting damping system. This increases stability in particular during straight driving, and thus the safety of the fitness device during mobile use. In an advantageous embodiment, it is provided that an additional damping element is disposed in a joint suspension disposed between the frame and the front axle. It is possible to provide a damping element only on one front wheel; as a rule, however, both front wheels are dampened by one damping element respectively. 
         [0018]    In one embodiment, it is provided that one side of the damping elements is respectively disposed on one wheel suspension. In particular, one side of a damping element ends in the vicinity of a hub of the corresponding wheel. Preferably, one side of the damping element is disposed in the vicinity of the wheel axle. This means that a distance to the wheel axle or the imaginary extension thereof is no greater than 10 centimeters, preferably smaller than 5 centimeters. Also, in one embodiment the distance to the wheel hub is no greater than 10 centimeters, preferably smaller than 5 centimeters. In another variation, it is provided that a transfer element is disposed between the wheel suspension and the damping element. The transfer element is preferably a rod or other rigid component disposed between the wheel suspension and one side of the damping element. In a particularly preferred embodiment, a piston shock absorber is provided as a damping element, with the piston rod being disposed towards the wheel. Alternatively, the cylinder piston may also be disposed towards the wheel. 
         [0019]    Another embodiment provides that at least one damping parameter of the damping elements is adjustable, preferably controllable. For example, a compression stage and/or a rebound stage of the damper can be adjusted. Preferably, a damper hardness can be adjusted. It is further preferred that an adjustment of a damping parameter takes place via a bypass line. Furthermore, it is provided in one variation that a cross section of an oil duct is variable. Preferably, an adjustment takes place by means of at least one adjusting screw. In one embodiment, it is also provided that the damping elements are replaceable. The damping action can be designed to be linear or progressive. For example, a progression behavior of the damper can be adjusted. The adjustment of at least one damping parameter offers the advantage that an adaptation of the driving behavior or steering behavior can be adjusted to a body weight of a user. Moreover, the damping behavior can be adjusted to a surface that is to be driven over. For example, a different damping behavior is required for smooth road surfacings than for uneven dirt roads. 
         [0020]    Another variation provides that the damping elements comprise a tilting stop. For example, a tilting stop is determined by a maximum penetration depth or a maximum extension of the respective damping element. It is also provided that an additional device is provided within or outside of the piston cylinder which causes a stop. Preferably, the movement of the piston rod is limited by the tilting stop. In a preferred variation, the tilting stop is adjustable. Furthermore, one embodiment provides that the frame can be tilted by 5° to 20°, preferably by 10° to 15°, preferably 11° from the vertical plane extending along a longitudinal axis of the fitness device. 
         [0021]    In another embodiment, the fitness device comprises a returning mechanism for returning the frame into the vertical plane. In particular, the damping element comprises a suitable spring member that supports a return into an upright position, i.e. into straight-line running. In one development, it is provided that the returning element comprises a spring member. In one configuration, the spring member is a coil spring. In another configuration, the spring member is a leaf spring. Particularly preferably, it is provided that the spring member is an air spring. The air spring damper offers the advantage that it has both damping properties as well as spring properties. In particular, the air spring damper acts as a returning element. In another embodiment, it is provided that the returning mechanism comprises several or a combination of spring members, for example a coil spring and an air spring. Preferably, a, for example hydraulic, piston damper comprises a spring disposed in the piston cylinder as a returning element. In principle, the returning mechanism can be formed by various suitable devices; the above-mentioned examples are not supposed to limit the invention thereto. 
         [0022]    In a particularly advantageous embodiment, the tilting steering mechanism or the returning mechanism is configured in such a way that the tilt takes place about a pivot point which, if possible, is disposed above at least the horizontal section of the frame. In their lower position closest to the ground surface, the treads are also located below the pivot point. It is thus accomplished that the return of the frame into the vertical or upright position is supported by the mass below the pivot point. Due to the fact that the body weight acts via the treads below the pivot point, the driving behavior of the fitness device is steadier and more stable. The return into the upright position takes place in a smooth manner, which is advantageous especially in the case of fast driving or in tight turns. 
         [0023]    A particularly advantageous development comprises the integration of a gear shifting unit through which the transmission ratio of the drive can be adjusted. Similar to a bicycle, an adjustment to the terrain and/or the strength of the user as well as to the speed can be carried out. 
         [0024]    The frame of the fitness device comprises one or more preferably lockable folding mechanisms, for example for easy transport or storage of the fitness device. The folding mechanism preferably comprises a hinge, which for example is disposed in such a way that individual parts of the frame can be folded relative to one another in the plane of the frame. Several folding mechanisms or hinges can be provided in order to enable the fitness device to be folded together so as to save as much space as possible. 
         [0025]    In another advantageous embodiment, the fitness device comprises a permanent brake by means of which the driving resistance can be adjusted. Preferably, the intensity of the permanent brake is adjustable. During mobile operation of the fitness device, the permanent brake increases training efficiency. It is particularly preferred that the permanent brake is detachably disposed on the fitness device. 
         [0026]    Furthermore, one embodiment provides that at least the rear wheel can be lifted by means of a stand so that the fitness trainer can be used stationarily. The stand on which the fitness device can be placed for stationary operation in one embodiment can thus be made substantially smaller and configured to save more space than, for example, a stationary bike trainer which as a rule requires a flywheel. In one embodiment, the permanent brake is a hydrodynamic brake or an eddy current brake. 
         [0027]    Preferably, an adjustment of at least one damping parameter of the first and/or second damping element is possible. For example, an adjustment dependent on a selected gear, a speed and/or a body weight of a user is provided. Preferably, the adjustment of the damping parameter can take place automatically. For example, it is provided in one embodiment that a body weight of a user is determined by means of a weighing mechanism and an adjustment of the damping parameter takes place automatically. It is provided in another embodiment that the gear shifting unit is connected to the first and/or second damping element and the damping parameter of the first and/or second damping element is adapted automatically by actuating the gear shifting unit. 
         [0028]    In one embodiment, the damping element is a piston damper with a maximum length of 240 millimeters to 260 millimeters. In one embodiment, the piston damper has a stroke of 40 millimeters to 50 millimeters, preferably about 44 millimeters. Moreover, one variation provides that the damper exerts a force of 2000 newtons at a piston rod movement of 350 millimeters per second. Depending or the requirements and the application, however, other dimensions are possible. The movement path, the frequency and the force that the damper exerts result depending on the piston damper length and the stroke. 
         [0029]    The mobile fitness device can not only be used as a bicycle-related means of transport, but also in a stationary manner. A so-called stationary bike trainer comprising braked support rollers can be used for stationary use. Both in stationary use as well as if the training device is used as a means of transport, the musculature of the legs and the upper body musculature are utilized and trained. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    Other advantageous embodiments become apparent from the following drawings. However, the developments depicted therein are not to be construed to be limiting; rather, the features described therein can be combined with one another and with the above-described features to constitute further embodiments. Furthermore, it should be noted that reference numerals indicated in the description of the Figures do not limit the scope of protection of the present invention, but merely refer to the exemplary embodiments shown in the Figures. Identical parts or parts that have the same function have the same reference numerals below. In the Figures: 
           [0031]      FIG. 1  shows a fitness device; 
           [0032]      FIG. 2  shows a detailed view of a fitness device; 
           [0033]      FIG. 3  shows another detailed view of the fitness device; 
           [0034]      FIG. 4  shows a schematic diagram of a tilting steering mechanism of a fitness device; 
           [0035]      FIG. 5  shows a damping element; and 
           [0036]      FIG. 6  shows a detailed view of a steering assembly; 
       
    
    
     DETAILED DESCRIPTION 
       [0037]      FIG. 1  shows a fitness device  1  in the form of a mobile crosstrainer with arm drive rods  2  and leg drive rods  3  disposed on both sides of a frame  4 . Treads  3 . 1  that enable a user to stand firmly when using the fitness device  1  are disposed on the leg drive rods  3 . 
         [0038]    In the embodiment shown, the fitness device  1  has a rear wheel  5  and two front wheels  6 . The steering assembly  7  enforces a steering movement of the front wheels  6  suspended on the front axle  8 . The damping elements  9  disposed between the frame  4  and the front wheels  6  are can be clearly seen. In the embodiment shown, the damping elements  9  are configured as piston dampers. 
         [0039]    Further,  FIG. 1  shows that the leg drive rods  3  are connected to a ring gear  10 , in the exemplary embodiment shown via a crank, in such a way that a moment generated by applying force to the leg drive rods  3  can be applied to the ring gear  10 . A moment is transferred to the rear wheel via a chain or belt not shown herein. In one embodiment, the rear wheel hub  11  comprises a dynamo, which is not shown in more detail herein, preferably a hub dynamo. Moreover, it is provided in one embodiment that the rear wheel hub  11  comprises a permanent brake which can be additionally switched in as required. It is moreover preferred that the brake force of the permanent brake is adjustable. 
         [0040]      FIG. 2  shows a detailed view of the fitness device  1 , from which the arrangement of the treads  3 . 1  on the leg drive rod  3 , on the one hand, and the steering assembly  7 , on the one hand, can be seen in detail. In principle, the steering assembly  7  can be configured variably with regard to its form or design to match the requirements. 
         [0041]    Damping elements  9  that, with one side, are disposed on the frame  4  and, with the other side, on a wheel suspension  12 , on which the front wheels  6  are arranged in turn, are assigned to the steering assembly  7 . In one embodiment, the damping elements  9  are disposed as closely as possible to the respective hub  13  of the front wheels. The embodiment shown in  FIG. 2  comprises transfer elements  14  that keep a defined distance of one side of the damping elements  9  from the wheel hub  13  or the axis of rotation of the front wheels  6 —which is not shown in more detail for the sake of clarity. 
         [0042]      FIG. 3  shows another detailed view of the fitness device  1 . The hinged joint  15  between the arm drive rod  2  and the leg drive rod  3  can be seen clearly. Moreover, a folding mechanism  16 , which in particular is configured to be lockable, is apparent from  FIG. 3 . 
         [0043]    The steering assembly  7  is actuated by tilting the frame  4  in relation to the front axle  6 . For this purpose, a joint  17  is disposed between the front axle  6  and the frame  4 , which in one version comprises another rotary damping element not shown in more detail herein. Track rods  18  are also shown which act on the front wheel suspension  12  if the frame  4  is tilted. 
         [0044]    In order to illustrate the mode of operation of the tilting steering mechanism,  FIG. 4  shows a schematic drawing of the fitness device  1 . The left-hand illustration shows the fitness device  1  in a resting position or during straight driving, and the right-hand drawing shows the fitness device  1  when driving towards the right. 
         [0045]    During straight driving, the frame  4  is in a vertical plane  19  that protrudes orthogonally from the plane of the image. The maximum possible tilting angles are marked with the reference numeral  20 ; they are preferably between 5° and 20°, preferably between 10° and 15°, particularly preferably about 11° in both directions. 
         [0046]    It can be seen that the damping elements  9 . 1  and  9 . 2  are in a center stroke position during straight driving. If the frame is tilted by the tilting angle  20 , the damping element  9 . 1  is completely extended, i.e. a piston rod, which is not marked in more detail herein, has a maximum stroke. Furthermore, a piston rod of the damping element  9 . 2  has a minimum stroke. The limitation of the stroke of the damping elements  9 . 1  and  9 . 2  in one embodiment acts as a tilting stop which limits a tilt of the frame  4  from the vertical plane  19  to a maximum tilting angle  20 . 
         [0047]    In this illustration, the pivot point of the tilting steering mechanism is disposed at a very low position; preferably, however, it can be provided as high as possible relative to the ground surface. This improves the return to the upright position about the pivot point. In particular  FIGS. 1-3  illustrate that a horizontal section of the frame  4  is disposed below the pivot point, i.e. the joint  17  (relative to the vertical). 
         [0048]      FIG. 5  shows a damping element  9  in different stroke positions. The damping element comprises a piston  22  with a piston rod  23 , which in one embodiment—in this case outlined by way of example in the left-hand illustration—comprises a thread  23 . 1  for attachment. Furthermore, the damping element  9  comprises an oil chamber  24  in which a damping piston  25  disposed on the piston rod  23  can be moved. Furthermore, a coil spring  26 , which acts as a stop and returning element, is located in the oil chamber. An air chamber  28 , which is separated from the oil chamber  24  by a movable partition wall  29 , provides for a progressive behavior of the damping element. In the case of a rapid movement of the damping piston  25  in the direction of the air chamber  28 , the gas in the air chamber, and thus the oil, is thus strongly pressurized and pressed through the openings in the piston rod, which are not shown in more detail herein. This can be seen in the left-hand illustration of  FIG. 5 . If the damping piston  25  moves quickly in the direction of the coil spring, a negative pressure is generated in the air chamber  28 , which draws oil through the openings of the damping piston  25 . This can be seen in the right-hand illustration of  FIG. 5 . In the case of a slow movement of the damping piston  25 , hardly any pressure is exerted on the air chambers  28  so that the oil flows through the openings in the damping piston in a similar manner as in a hydraulic damper that is not configured to be progressive. 
         [0049]    The center illustration of  FIG. 5  shows the damper piston, preferably during straight driving of the fitness device. The illustrations on the left and the right show maximum steering movements. It is apparent in particular from the right illustration that the coil spring  26  is biased in the case of a steering movement. If a force on the piston rod  23  is reduced, the coil spring  26  causes a return steering action into straight driving. 
         [0050]      FIG. 6  shows a detailed view of a steering assembly  7 . The steering assembly  7  comprises a track rod  18 , which, if the frame  4  is tilted, acts on a lever element  29 , which in turn is disposed on a steering element  30 . The steering element  30  is rotatably disposed in an accommodating portion  31 , with the accommodating portion  31  being disposed on the front axle  6 . Furthermore, the steering element  30  comprises the wheel suspension  12  on which the front wheel  6  is rotatably suspended. The damping element  9  is disposed between the front wheel suspension  12  and the frame  4 .