Self-righting two-wheeled vehicle

Abstract

A two-wheeled vehicle for children, in particular a balance bicycle for children, comprising: - a frame (1), - two wheel assemblies (3, 4) attached one behind the other centrally on the frame (1) along a ground-parallel longitudinal axis (2) of the two-wheeled vehicle - and a steering system (5) for steering the front wheel (3), - wherein at least the rear wheel (4), preferably both wheels (3, 4), has / have a bulge-like rounded tire contour (8) along which the point of contact (9) with the ground is located, the point of contact depending on the lateral inclination of the two wheeled vehicle about the longitudinal axis (2), - wherein the tire contour (8) has a central straight-line motion region (10) and also has, on both sides of said straight-line motion region (10), cornering regions (11) that curve outward toward the tire shoulders, allowing cornering maneuvers to be performed at a lateral tilt, - and wherein the tire contour (8) is designed such that, at a lateral inclination about the longitudinal axis (2) within certain tipping angle limits (14', 14''), the two-wheeled vehicle rights itself unaided while stationary, in particular in accordance with the principle used for a round-bottomed doll.

Description

[0001] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0002] Self-righting two-wheeler

[0003] The invention relates to a two-wheeled bicycle for children according to the preamble of the independent patent claims.

[0004] When children learn to ride a bicycle, maintaining balance is one of the biggest challenges. The younger the children, the harder it is for them to overcome the initial lack of stability of a stationary bicycle in order to transition into stable forward motion.

[0005] For this reason, tricycles or bicycles with wide, cylindrical wheels are very popular with younger children. Tricycles and similar vehicles are very stable even when stationary, which makes starting and getting on much easier for children. This stability also makes them easier for parents to handle, as a tricycle can simply be parked upright, whereas a conventional bicycle falls over if it isn't held.

[0006] A disadvantage of stable, three-wheeled or cylindrical vehicles is that the riding technique differs fundamentally from that required for a two-wheeler, such as a balance bike or bicycle. While on a balance bike or bicycle, one must lean inwards when turning, children on tricycles often develop the habit of steering solely by turning or even leaning outwards. This significantly complicates the later transition to a bicycle or balance bike.

[0007] This creates a conflict of objectives for children's bicycles between ease of use and learning the techniques for riding a regular balance bike or bicycle. Additionally, the bicycle should also be simple and robust in its construction.

[0008] The purpose of the invention is now to overcome the disadvantages of the prior art and, in particular, to resolve this conflict of objectives.

[0009] The problem is solved in particular by the features of independent patent claims.

[0010] The invention relates to a two-wheeled bicycle for children and in particular a children's balance bike, comprising:

[0011] - a frame,

[0012] - two wheels mounted centrally one behind the other on the frame, parallel to the ground and rotatable

[0013] - and a steering mechanism for steering the front wheel.

[0014] All components of the two-wheeler define a common center of gravity and a center of gravity axis running parallel to the longitudinal axis through the center of gravity.

[0015] It is advantageous if at least the rear wheel, preferably both wheels, have a convexly curved tire profile along which the point of contact with the ground lies, depending on the lateral tilt of the two-wheeler around its longitudinal axis. Woom GmbH, Muthgasse 109a, 1190 Vienna (AT)

[0016] Furthermore, it is advantageous if the tire contour has a central straight-line running area and, on both sides of the straight-line running area, curved areas running outwards towards the tire shoulders for laterally inclined cornering.

[0017] Preferably, the tire contour is designed such that the radius of curvature of the average curvature of the tire contour is larger than the average normal distance of the center of gravity axis from the tire contour.

[0018] Preferably, the tire contour is designed in such a way that the two-wheeler, in the event of a lateral tilt about the longitudinal axis within certain tilt angle limits, automatically rights itself when stationary, in particular according to the self-righting toy principle.

[0019] Preferably, the tire contour is designed such that a lateral tilting of the two-wheeler about the longitudinal axis from an upright central position and within lateral tilt angle limits causes a raising of the center of gravity and a righting moment, whereby gravity automatically rights the two-wheeler when stationary.

[0020] Preferably, the tipping angle limits, measured from the upright position of the two-wheeler about its longitudinal axis, within which the two-wheeler automatically rights itself when stationary, are more than 10°, preferably more than 15°, particularly preferably more than 20°, and especially between 20° and 30°. The tipping angle limits are preferably less than 45°.

[0021] If necessary, the two-wheeler is provided for to have at least one righting weight in its lower area to reduce the center of gravity height.

[0022] If necessary, the righting weight, in the event of a lateral tilt of the two-wheeler around its longitudinal axis within the tilt angle limits, together with the tire contour and the other components of the two-wheeler, generates a righting moment that automatically rights the two-wheeler when stationary. 65219 Woom GmbH, Muthgasse 109a, 1190 Vienna (AT)

[0023] Optionally, a righting weight is provided inside one of the wheels. Optionally, a righting weight is provided in each of the two wheels.

[0024] If necessary, a stationary axle is provided on the frame, on which one of the wheels is rotatably mounted, with a righting weight attached to this axle.

[0025] If necessary, a counterweight is arranged below the height of the axis.

[0026] If necessary, a righting weight is attached in or to the frame in the lower area, particularly in the lower third or lower quarter, of the bicycle.

[0027] If necessary, the erection weight is intended to have a density greater than 3 g / cm³. 3 , preferably greater than 6 g / cm² 3 exhibits.

[0028] If applicable, a seat or saddle is provided, and the two-wheeler is designed as a child's balance bike.

[0029] Preferably, the frame extends to below the height of the wheel hub(s) or axle(s) of one or both wheels. Preferably, a counterweight is provided in this area of ​​the frame and is particularly attached to or within the frame.

[0030] Where appropriate, it is intended that the frame and in particular other components of the two-wheeler, such as the handlebars or the seat, are formed or assembled from lightweight components such as aluminum hollow profiles, plastic hollow bodies, foamed plastic parts and / or fiber-reinforced plastic parts.

[0031] Where applicable, the curved sections are designed to enable stable banked cornering with a curve radius dependent on the angle of inclination around the longitudinal axis. Woom GmbH, Muthgasse 109a, 1190 Vienna (AT)

[0032] If necessary, it is provided that the lowest point of the wheel, which is also the contact area with the ground, lies in one of the curve areas when cornering at an angle.

[0033] If necessary, the straight-line running area is provided for as a central, flattened section of the tire contour, which forms a contact area for the stable upright positioning of the two-wheeler.

[0034] Optionally, it is provided that the width of the straight-ahead running area measured along the tire contour is less than 40%, preferably less than 30%, particularly preferably less than 25% but optionally more than 10% and preferably more than 20% of the total tire contour.

[0035] If necessary, the width of the straight-ahead running area measured along the tire contour is less than 6cm, preferably less than 5cm and particularly preferably less than 4cm, but possibly more than 2cm and preferably more than 3cm.

[0036] If necessary, the straight-ahead running area is provided with a transition area on both sides, which forms a smooth or rounded transition to the adjacent curve area.

[0037] The two-wheeler is preferably designed in such a way that it can be ridden using essentially the same technique as a balance bike or bicycle, while at the same time remaining stable in its upright position when stationary. This is achieved in particular through a special kinematic design of the tire contour, taking into account the center of gravity of the two-wheeler.

[0038] The basic design can correspond to that of a conventional two-wheeler. Preferably, it includes a frame, two wheels (a front wheel and a rear wheel), and a steering mechanism for the front wheel. The rear wheel is preferably non-steerable. The steering mechanism preferably forms part of the frame. Preferably, the two-wheeler comprises exactly two wheels. Woom GmbH, Muthgasse 109a, 1190 Vienna (AT)

[0039] Both wheels preferably feature a convexly curved tire profile. This curved tire profile allows the two-wheeler to be tilted laterally around a longitudinal axis for stable cornering. The tire profile is specifically designed such that the turning radius is, in the conventional manner, dependent on the tilt angle of the two-wheeler.

[0040] The tire contour is also designed in such a way that the two-wheeler, particularly according to the self-righting principle, rights itself automatically when stationary. If the stationary two-wheeler is tilted sideways around a longitudinal axis from an upright position, it will right itself automatically when released. This kinematic effect is achieved primarily by designing the tire contour in such a way that a lateral tilt of the two-wheeler around its longitudinal axis from an upright central position, within certain lateral tilt angle limits, causes the center of gravity to rise and generates a righting moment, which in turn allows gravity to automatically right the two-wheeler.

[0041] This effect can be achieved, in particular, by positioning the bicycle's center of gravity lower than the center of curvature of the tire's contour. When the bicycle is tilted laterally in one direction, the point of contact between the wheel and the ground moves along the tire's contour into the curved section of the wheel. During this movement, the bicycle's center of gravity also shifts laterally, but in the tilted state, it lies on the opposite side of a perpendicular line drawn from the point of contact. This generates a righting moment that returns the bicycle to its upright position.

[0042] Preferably, the curvature of the tire contour in the area of ​​the lowest point of the wheel, which is also the contact area with the ground, defines a local center of curvature in every tilting position of the two-wheeler about the longitudinal axis within lateral tilting angle limits, and optionally the tire contour is designed such that in every tilting position of the two-wheeler between the tilting angle limits, the local center of curvature lies higher than the center of gravity of the two-wheeler in this tilting position, whereby gravity does not affect the Woom GmbH, Muthgasse 109a, 1190 Vienna (AT)

[0043] A two-wheeler that rights itself automatically when stationary, especially according to the self-righting principle of a roly-poly toy.

[0044] It is advantageous if the center of gravity of the two-wheeler is as low as possible. The lower the center of gravity, the smaller, for example, the radius of curvature of the tire contour can be, the less mass the righting weight can be, and / or the easier it is to lean the two-wheeler into a curve.

[0045] Preferably, the center of gravity is located at the height of the wheel hubs or axles. However, it is not absolutely necessary for the center of gravity to be located below the axles of the wheels.

[0046] According to one possible embodiment, the two-wheeler has a wheelbase of approximately 350 to 500 mm.

[0047] According to this or another embodiment, the radius of curvature of the average curvature of the tire contour of the wheel is between 120 mm and 180 mm, preferably approximately 150 mm.

[0048] The required radius of curvature of the tire contour depends in particular on the position of the two-wheeler's center of gravity. According to one embodiment, the radius of curvature of the tire contour is approximately 150 mm and the center of gravity should be located at a height of approximately 90 mm.

[0049] The wheel can, for example, have a diameter of 150 to 200 mm, for example 175 mm.

[0050] To define the kinematic conditions, the radius of curvature of the average curvature of the tire contour can be related to the location of the center of gravity. 65219

[0051] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0052] The tire contour can be circular, at least in sections, or have a shape other than a circle. For example, the tire contour may have a segmented circular shape in its curves and be flattened in the straight-line section. The curves may also be parts of an ellipse or another curved shape.

[0053] In all embodiments, the straight-ahead running area can form a central, cylindrical-shaped section of the wheel.

[0054] Preferably, in all embodiments, the tire contour has a convex curved shape to enable stable, inclined cornering.

[0055] Since the radius of curvature of the tire contour does not have to be constant along its path, it can be approximated that the tire contour has an average radius of curvature. This is preferably the radius of curvature of the average curvature, and in particular a radius of curvature that deviates as little as possible from the tire contour, and which the tire contour consequently follows with certain deviations. For example, an arithmetic mean of the curvature of the tire contour can be used for the calculation. Deviations caused by the tire tread pattern should be disregarded.

[0056] To define the center of gravity, one can, for example, assume an axis that is parallel to the ground (i.e., parallel to the longitudinal axis) and that also passes through the center of gravity of the two-wheeler. The position of the center of gravity can then be defined by a perpendicular distance from this center of gravity axis to the tire contour.

[0057] The wheels have a tire contour that is essentially unchanged along the circumference or tread. For the sake of simplicity, the tire contour itself is assumed to be in the area where the wheel contacts the ground, i.e., at the lowest point of the wheel and preferably in a plane normal to a longitudinal axis. Woom GmbH, Muthgasse 109a, 1190 Vienna (AT)

[0058] To positively influence the position of the center of gravity, a righting weight is preferably provided. This righting weight is preferably positioned as low as possible.

[0059] For example, the righting weight can be located in or at the bottom of the frame.

[0060] Alternatively or additionally, a righting weight can be arranged on one or both wheels. For example, a weight can be attached to the axle of one of the wheels and extend downwards from this axle when the bicycle is upright. For example, the axle may be rigidly mounted, and the wheel may be rotatably attached to this rigid axle via a bearing in the wheel hub. The righting weight can then be rigidly arranged relative to the axle and preferably project downwards from the axle. A counterweight can be provided at the front wheel and / or the rear wheel.

[0061] The wheel may include an interior space, and the righting weight may be located within this space. Alternatively, the righting weight may be attached to the wheel itself, for example, to a fixed hubcap.

[0062] In all embodiments, it is preferably provided that the righting weight is rigidly connected to the frame or one of the axles. In particular, the righting weight is preferably not rotatably arranged in all embodiments.

[0063] According to a preferred embodiment, the frame extends below the axle or below the wheel hub. The righting weight can be located in this area of ​​the frame.

[0064] The function that allows the two-wheeler to automatically right itself from a tilted position when stationary is preferably limited to certain tilt angle limits. This makes it possible to lay the two-wheeler flat on its side without it automatically righting itself. Furthermore, this allows the center of gravity of the two-wheeler to be positioned somewhat higher or a righting weight with a smaller mass (Woom GmbH, Muthgasse 109a, 1190 Vienna, Austria) to be used, thus simplifying the design. The tilt angle limits within which the wheel automatically rights itself are preferably greater than 10°, preferably greater than 20°, and particularly in the range of approximately 25° to 30°. This refers to the lateral tilt angle of the two-wheeler about a longitudinal axis.

[0065] The frame of the bicycle can, for example, be made of aluminum tubes.

[0066] The seat can, for example, be formed from a hollow body made of a solid plastic such as EPP or PP.

[0067] The elements designed as forks to hold the wheels can be made of aluminum hollow profiles or of a lightweight construction made of plastic, such as glass fiber reinforced plastic, like glass fiber reinforced polypropylene.

[0068] The wheel can consist of a rigid base or rim and a soft, elastic tread. In this case, the tread also forms the tire contour. The tire contour can include a straight-line running zone and a cornering zone, with the cornering zones extending in a curved path from the centrally located straight-line running zone towards the tire shoulders.

[0069] The base body or rim can be designed as a hollow or lightweight structure and made, for example, of a rigid plastic such as polypropylene, PVC, or similar materials. The tread can be made, for example, of an elastic or soft material such as EVA.

[0070] In general, it can be advantageous to construct all components above the center of gravity, or all components except for the righting weight, from lightweight materials. 65219

[0071] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0072] Lightweight materials can include, for example, hollow profiles made of aluminum, lightweight structures made of fiber-reinforced plastic, or hollow plastic bodies.

[0073] The righting weight is preferably a body connected to another component, preferably the frame and / or a wheel or its axle. The righting weight is preferably made of a different material than the frame or the wheel. In all embodiments, the righting weight is preferably made of a material with a higher density than a lightweight material, for example, steel. In particular, the righting weight is a solid, solid, or composite steel part.

[0074] The tilt angle limits are preferably those limits within which the righting effect occurs. Preferably, the wheels and their tire contours are designed such that the two-wheeler does not automatically right itself when tilted laterally about its longitudinal axis outside the tilt angle limits. This allows the wheels and all components, with the exception of the handlebars, to be designed with a narrow profile, for example, to fulfill the function of a child's balance bike.

[0075] Preferably, the seat or saddle is positioned on the bicycle in such a way that it can function as a child's balance bike. To this end, the seat or saddle should be positioned high enough to allow the bicycle to function in a seated walking motion, as is typical for the use of a child's balance bike.

[0076] Preferably, all components of the two-wheeler are designed in such a way that it can fulfill the function of a child's balance bike. Freedom of movement when operating the two-wheeler is particularly important. The wheels, especially the rear wheel, should only be wide enough to allow the seated walking motion typical for operating a child's balance bike, and in particular, to ensure that the leg movement to the rear is not restricted. The rear wheel, or both wheels if applicable, has a width that is preferably less than 20 cm, and particularly preferably less than 15 cm. 65219

[0077] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0078] In all embodiments, the straight-ahead running area can be flattened and / or curved.

[0079] The invention will be further described using the figures.

[0080] Fig. 1 shows a schematic oblique view of a possible embodiment of a two-wheeler.

[0081] Fig. 2 shows a schematic representation of the kinematic conditions of a two-wheeler.

[0082] Fig. 3 shows a side view of an embodiment of a two-wheeler, in particular the embodiment from Figure 1.

[0083] Fig. 4 shows a schematic sectional view of a two-wheeler in the area of ​​one wheel.

[0084] Unless otherwise specified, the reference symbols in the figures correspond to the following components:

[0085] Frame 1, longitudinal axis 2, front wheel 3, rear wheel 4, steering 5, center of gravity 6, center of gravity axis 7, tire contour 8, contact point 9, straight-line running area 10, curve area 11, radius of curvature 12, normal distance 13, tipping angle limit 14, righting weight 15, interior (of the wheel) 16, axle 17, wheel hub 18, transition area 19.

[0086] Fig. 1 shows a schematic oblique view of a two-wheeled vehicle. The two-wheeled vehicle comprises a frame 1 and two wheels 3, 4 arranged along the longitudinal axis 2, in particular a front wheel 3 and a rear wheel 4. In all embodiments, the two-wheeled vehicle is preferably designed as a single-track vehicle. The two wheels 3, 4 are therefore arranged centrally one behind the other along the longitudinal axis 2 and are preferably rotatably mounted on the frame.

[0087] The front wheel 3 is steerable via a steering mechanism 5. The rear wheel 4 is preferably unsteered, meaning that the axle 17 of the rear wheel 4 is essentially rigidly connected to the frame 1. This is a conventional design for a balance bike or bicycle. 65219

[0088] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0089] All components of the two-wheeler together define a center of gravity 6. In addition, a center of gravity axis 7 is assumed, which runs through the center of gravity 6 on one side and parallel to the longitudinal axis 2 on the other.

[0090] At least one of the wheels 3, 4, or in the present embodiment both wheels 3, 4, has a convexly curved tire contour 8. When the two-wheeler is tilted laterally about a longitudinal axis 2, the contact point 9 moves outwards along this tire contour 8 towards the tire shoulder. In the upright position or when traveling straight ahead, the contact point 9 is thus located in a central straight-line running area 10, and when cornering or when the two-wheeler is tilted to the side, the contact point is located in one of the two curve areas 11. The curve areas 11 preferably extend on both sides of the straight-line running area 10 towards the tire shoulders.

[0091] A transition zone 19 is preferably provided for the transition from the straight-line running zone 10 to the curve section 11. The transition zone can be considered part of the straight-line running zone 10.

[0092] The tire contour 8 enables stable cornering, during which the two-wheeler is tilted about a longitudinal axis 2. The turning radius is preferably dependent on the tilt angle of the two-wheeler about the longitudinal axis 2.

[0093] In addition, the tire contour 8 is designed in all embodiments such that the two-wheeler, within certain tilting angle limits 14', 14", in particular according to the self-righting toy principle, automatically rights itself when stationary if, for example, it is tilted to the side by an external force.

[0094] This is achieved in particular by designing the tire contour 8 such that the radius of curvature 12 of the average curvature of the tire contour 8 is larger than the average normal distance 13 of the center of gravity axis 7 from the tire contour 8. 65219

[0095] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0096] In other words, the tire contour is designed in such a way that a lateral tilting of the two-wheeler about a longitudinal axis 2 from an upright central position and within lateral tilt angle limits 14', 14" causes a raising of the center of gravity 6 and a righting moment.

[0097] The two-wheeler preferably includes a steering rod 5, with which manual steering can be carried out.

[0098] In all embodiments, the two-wheeler can include a seat that projects from the frame 1, so that the two-wheeler, as in the present embodiment, is designed as a balance bike. Alternatively, it is also possible to equip the two-wheeler with pedals, thus forming a bicycle. Alternatively, the seat can be omitted, and a standing platform can be provided in the lower part of the frame 1 instead, in which case the two-wheeler is designed as a scooter or kick scooter. In a scooter embodiment, the steering mechanism 5 or the head tube of the two-wheeler can be longer to form a conventional scooter configuration.

[0099] In all embodiments, those components located above the center of gravity 6 are preferably designed as lightweight components. For example, the frame 1 can be formed or assembled from a hollow aluminum tube. Preferably, the seat can be formed from a hollow body made of plastic or light metal. In all embodiments, the wheels 3, 4 can also be made of lightweight materials. This has the advantage that the moment of inertia of the wheels 3, 4 during acceleration and braking is reduced, and the agility of the two-wheeler is improved.

[0100] In the present embodiment, the connection between the frame 1 and the respective wheel 3, 4 is designed as a one-sided swingarm or as a one-sided fork leg. According to an alternative embodiment, however, a conventional fork can be provided to support the axle 17.

[0101] Figure 2 describes in more detail the kinematic conditions for achieving the self-righting effect. In particular, two positions are shown. In a 65219

[0102] Woom GmbH, Muthgasse 109a, 1190 Vienna (AT) In the first position, the contact point 9 lies within the straight-ahead running area 10 of the tire contour 8. This is, for example, a position in which the two-wheeler is upright. The center of gravity 6 and the center of gravity axis 7 projected in this illustration are located centrally above the straight-ahead running area 10. In all embodiments, the straight-ahead running area 10 is preferably a centrally arranged, flattened area of ​​the tire contour 8, which is intended to enable a stable central position of the two-wheeler.

[0103] The tire contour 8 is convexly curved and consequently has a radius of curvature 12. This radius of curvature can be constant along the curve section 11. Alternatively, the radius of curvature 12 can vary along the tire contour 8 in the curve section 11. In the present embodiment, the radius of curvature 12 is constant in the curve section 11, or in both curve sections 11. Only in the straight-line section 10, which is designed as a flattened area, does the radius of curvature 12 vary.

[0104] The tire contour 8 is now designed such that the radius of curvature 12, in particular the average radius of curvature 12 along the tire contour 8, is larger than the normal distance 13 of the center of gravity axis 7 to the tire contour 8. Here, too, the average normal distance of the center of gravity axis 7 to the tire contour 8 can be assumed.

[0105] If the two-wheeler is now tilted to the side, the point of contact 9' with the ground is located in the curve area 11'. Tilting the two-wheeler naturally also moves the center of gravity 6 and the center of gravity axis 7.

[0106] In the inclined position, the center of gravity 6' and the center of gravity axis 7' lie at a specific distance from the vertical line above the point of contact 9'. Due to the special design of the tire contour, when the two-wheeler is tilted in one direction, the center of gravity 6' lies on the opposite side of a vertical line assumed to be above the point of contact 9'. This displacement of the center of gravity 6' from the point of contact 9' creates a righting moment, and the two-wheeler automatically rights itself according to the principle of a self-righting toy. The same process occurs analogously when the two-wheeler is tilted to the other side. 65219

[0107] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0108] When the two-wheeler is tilted about a longitudinal axis 2 from its central position, the center of gravity 6 or the center of gravity axis 7 is preferably also raised due to the special design of the tire contour 8. This also causes a restoring torque and the righting of the two-wheeler.

[0109] According to the present configuration, this effect can be used within two tipping angle limits 14', 14". If the two-wheeler is moved beyond a tipping angle limit 14", the center of gravity also moves beyond the vertical of the point of contact 9, and the two-wheeler can tip over.

[0110] Fig. 2 is not an exact scale kinematic representation, i.e., the angles and lengths may be distorted.

[0111] Fig. 3 shows a schematic side view of a possible embodiment of a two-wheeler, in particular the two-wheeler from Fig. 1. The components described in Fig. 1 are also found in Fig. 3 in an analogous manner. Fig. 3 additionally shows the arrangement of a righting weight 15. This righting weight 15 is arranged in the lower region of the two-wheeler, in any case below the center of gravity axis 7 or the center of gravity 6, and serves to lower the center of gravity compared to a design without a righting weight 15. The righting weight 15 can be arranged in the region of the front wheel 3, in the region of the rear wheel 4, and / or in the lower region of the frame 1. In the present embodiment, these three possibilities for the placement of the righting weights 15 are shown, whereby any combination of the placement of righting weights 15 is also possible.

[0112] Preferably, the erection weight 15 is rigidly or immovably connected to the frame 1 or its steering system.

[0113] If the righting weight 15 is provided in the area of ​​a wheel 3, 4, it is advantageous if the righting weight 15 extends below the axle 17 or below the wheel hub 18. In particular, the righting weight 15 can be arranged below the axle 17 or the wheel hub 18. (65219 Woom GmbH, Muthgasse 109a, 1190 Vienna (AT))

[0114] Wheels 3 and 4 are therefore suitable because they are the element of the two-wheeler that extends furthest downwards. For this reason, the righting weight 15 can extend particularly far downwards in the area of ​​wheels 3 and 4, thereby shifting the center of gravity 6 downwards particularly effectively.

[0115] In the present embodiment of Figure 3, and particularly in all embodiments, the frame 1 can extend into the area near the ground. Specifically, the frame can extend into an area that, when the two-wheeler is upright, lies below the wheel hubs or below the axles 17. This allows a righting weight 15 on the frame 1 to be used particularly effectively in a low-lying area to lower the center of gravity. However, to ensure sufficient ground clearance, the frame 1 generally cannot extend as far down to the ground as the wheels 3, 4.

[0116] In all embodiments, the frame 1 can be partially formed by the erection weight 15.

[0117] Preferably, a rigid axle 17 is provided. The wheel 3, 4 has a pivot bearing in the area of ​​its wheel hub 18, by means of which it is rotatably mounted on the axle 17. Preferably, the leveling weight 15 is rigidly connected or rigidly coupled to the axle 17 so that it can be held motionless in a lower area.

[0118] Fig. 4 shows a schematic sectional view of a wheel 3, 4 in which a righting weight 15 is attached to the axle 17. In particular, the wheel 3, 4 has an interior space 16. The righting weight 15 is arranged in this interior space. As a result, the righting weight 15 is not visible or accessible from the outside. The righting weight 15 can be attached to a fixed axle 17, as described above.

[0119] In all embodiments, the wheel 3, 4, as shown in Fig. 4, can comprise a rigid base body and a soft elastic tread. In this case, the tread also forms the tire contour 8. The tire contour can comprise a straight-line running area 10 and a cornering area 11, wherein the 65219

[0120] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0121] Curved sections 11 are curved from the centrally arranged straight-ahead section 10.

[0122] Extend towards the tire shoulders.

Claims

Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) Patent claims 1. Two-wheeled bicycle for children, in particular children's balance bike, including: - a frame (1 ), - two wheels (3, 4) attached centrally one behind the other along a longitudinal axis (2) parallel to the ground of the two-wheeler on the frame (1) - and a steering mechanism (5) for steering the front wheel (3), - wherein all components of the two-wheeler define a common center of gravity (6) and a center of gravity axis (7) running parallel to the longitudinal axis (2) through the center of gravity, - wherein at least the rear wheel (4), preferably both wheels (3, 4), have a convexly curved tire contour (8) along which, depending on the lateral inclination of the two-wheeler about the longitudinal axis (2), the point of contact (9) with the ground lies, - wherein the tire contour (8) has a central straight-running area (10) and on both sides of the straight-running area (10) curved outwards towards the tire shoulders curve areas (11) for a laterally inclined cornering maneuver, - and wherein the tire contour (8) is designed such that the radius of curvature (12) of the average curvature of the tire contour (8) is greater than the average normal distance (13) of the center of gravity axis (7) from the tire contour (8) and the two-wheeler, when tilted laterally about the longitudinal axis (2) within certain tilt angle limits (14', 14"), in particular according to the self-righting principle, automatically rights itself when stationary.

2. Two-wheeled bicycle for children, in particular children's balance bikes, including: - a frame (1 ), - two wheels (3, 4) attached centrally one behind the other along a longitudinal axis (2) parallel to the ground of the two-wheeler on the frame (1) - and a steering mechanism (5) for steering the front wheel (3), - where all components of the two-wheeler share a common center of gravity (6) Woom GmbH, Muthgasse 109a, 1190 Vienna (AT) and define a center of gravity axis (7) running parallel to the longitudinal axis (2), - wherein at least the rear wheel (4), preferably both wheels (3, 4), has a bulbous curved tire contour (8) which has a central straight-running area (10) and curve areas (11) on both sides of the straight-running area (10) curving outwards towards the tire shoulders for a laterally inclined cornering action about the longitudinal axis (2), - and wherein the tire contour (8) is designed such that a lateral tilting of the two-wheeler about the longitudinal axis (2) from an upright central position and within lateral tilt angle limits (14', 14") causes a raising of the center of gravity (6) and a righting moment, whereby gravity automatically rights the two-wheeler when stationary, in particular according to the self-righting toy principle.

3. Two-wheeler according to claim 1 or 2, characterized in that the tilt angle limits (14', 14") measured from the upright position of the two-wheeler about the longitudinal axis (2), within which the two-wheeler automatically rights itself when stationary, are more than 10°, preferably more than 15°, particularly preferably more than 20°, in particular between 20° and 30°.

4. Two-wheeler according to one of claims 1 to 3, characterized in that, - that the two-wheeler has at least one righting weight (15) in its lower section to reduce the center of gravity height, - and that the righting weight (15), when the two-wheeler tilts laterally about the longitudinal axis (2) within the tilt angle limits (14', 14"), together with the tire contour (8) and the remaining components of the two-wheeler, generates a righting moment that automatically rights the two-wheeler when stationary.

5. Two-wheeler according to claim 4, characterized in that a righting weight (15) is provided in the interior (16) of one of the wheels (3, 4), in particular that a righting weight is provided in each of the two wheels (3, 4). Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) 6. Two-wheeler according to claim 4 or 5, characterized in that a stationary axle (17) is provided on the frame (1 ) on which one of the wheels (3, 4) is rotatably mounted, and that a righting weight (15) is attached to this axle (17).

7. Two-wheeler according to one of claims 4 to 6, characterized in that a righting weight (15) is arranged below the height of the axle (17).

8. Two-wheeler according to one of claims 4 to 7, characterized in that a righting weight (15) is attached in the lower area, in particular in the lower third or lower quarter, of the two-wheeler, in or on the frame (1).

9. Two-wheeler according to one of claims 4 to 8, characterized in that the righting weight (15) has a density greater than 3 g / cm³ 3 , preferably greater than 6 g / cm³ 3 exhibits.

10. Two-wheeler according to one of claims 1 to 9, characterized in that a seat or saddle is provided, and that the two-wheeler is designed as a children's balance bike.

11. Two-wheeler according to one of claims 1 to 10, characterized in that the frame extends to below the height of the wheel hub(s) (18) or the axles (17) of one of the wheels or of both wheels (3, 4).

12. Two-wheeler according to one of claims 1 to 11, characterized in that the frame (1) and in particular also other components of the two-wheeler such as the handlebars or the seat are formed or composed of lightweight components such as aluminum hollow profiles, plastic hollow bodies and / or fiber-reinforced plastic parts.

13. Two-wheeler according to one of claims 1 to 12, characterized in that, - that the curve sections (11 ) are designed to enable stable inclined cornering with a curve radius dependent on the inclination angle about the longitudinal axis (2), 65219 Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) - and that the lowest point of the wheel (3,4), which is also the contact area with the ground, lies in one of the curve areas (11) during inclined cornering.

14. Two-wheeler according to one of claims 1 to 13, characterized in that the seat or saddle is positioned on the two-wheeler in such a way that the two-wheeler can fulfill the function of a child's balance bike and enables a seated walking movement, which is usual for the operation of a child's balance bike.

15. Two-wheeler according to one of claims 1 to 14, characterized in that all components of the two-wheeler are designed in such a way that it can fulfill the function of a child's balance bike and the wheels, in particular the rear wheel, are only so wide that the two-wheeler enables a seated walking motion, as is usual for the operation of a child's balance bike.

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