Self-righting bicycle having at least one wheel assembly

Abstract

A bicycle for children, in particular a balance bicycle for children, comprising: - a frame (1), - two wheel assemblies (3, 4) attached centrally to the frame (1) one behind the other, - and a steering system (5) for steering the front wheel assembly (3), - wherein at least the rear wheel assembly (4) has a bulge-like rounded tire contour (8), - 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 the radius of curvature (12) of the average curvature of the tire contour (8) is greater than the average normal distance (13) from the center of gravity axis (7) of the bicycle to the tire contour (8) and the bicycle rights itself unaided while stationary, in particular in accordance with the principle used for a round-bottomed doll.

Description

[0001] 65220 / GP / -

[0002] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0003] Self-righting bicycle with at least one wheel arrangement

[0004] The invention relates to a bicycle for children according to the preamble of the independent patent claims.

[0005] 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.

[0006] 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.

[0007] A disadvantage of stable vehicles like tricycles or those with cylindrical wheels is that the riding technique differs fundamentally from that required for a bicycle, such as a balance bike or a regular bicycle. While on a balance bike or bicycle you have to lean inwards when turning, children on tricycles often get used to turning solely by steering or even leaning outwards. This makes the later transition to a bicycle or balance bike considerably more difficult.

[0008] 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 robustly constructed.

[0009] The purpose of the invention is now to overcome the disadvantages of the prior art and, in particular, to resolve this conflict of objectives.

[0010] The problem is solved in particular by the features of independent patent claims.

[0011] The invention relates to a bicycle for children and in particular a children's balance bike, comprising:

[0012] - a frame,

[0013] - two wheel assemblies mounted centrally one behind the other on the frame along a longitudinal axis parallel to the ground, allowing them to rotate

[0014] - and a steering system for steering the front wheel assembly.

[0015] All components of the bicycle define a common center of gravity and a center of gravity axis running parallel to the longitudinal axis through the center of gravity.

[0016] It is advantageous if at least the rear wheel arrangement, preferably both wheel arrangements, have a convexly curved tire contour along which, depending on the lateral inclination of the bicycle about the longitudinal axis, the point of contact with the ground lies.

[0017] Furthermore, it is advantageous if the tire contour has a central straight-line running area and, on both sides of this area, curves outwards towards the tire shoulders to facilitate side-leaning cornering. 65220 / GP / -

[0018] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0019] 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.

[0020] Preferably, the tire contour is designed in such a way that the bicycle, when tilted laterally around the longitudinal axis within certain tilt angle limits, in particular according to the self-righting toy principle, automatically rights itself when stationary.

[0021] Preferably, the tire contour is designed such that a lateral tilting of the bicycle 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 bicycle when stationary.

[0022] Preferably, the tilt angle limits, measured from the upright position of the bicycle about its longitudinal axis, within which the bicycle 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 tilt angle limits are preferably less than 45°.

[0023] If necessary, the bicycle is provided with at least one righting weight in its lower section to reduce the center of gravity height.

[0024] Optionally, it is provided that at least one of the wheel arrangements, preferably both wheel arrangements, is divided along a normal plane of the axle and comprises two lateral wheel shells arranged side by side, which together form the tire contour.

[0025] If necessary, a gap is left between the wheel shells.

[0026] If necessary, the gap width is less than 5 cm, preferably less than 3 cm. 65220 / GP / -

[0027] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0028] If necessary, the retaining element of the frame or steering system, on which the wheel assembly is held or supported, is provided for to protrude into the gap and be connected to the axle there.

[0029] If necessary, the lifting weight is arranged in the gap.

[0030] If necessary, the lifting weight is rigidly attached to the holding element.

[0031] If necessary, it is provided that, in the event of a lateral tilt of the bicycle around the longitudinal axis within the tilt angle limits, the righting weight, together with the tire contour and the remaining components of the bicycle, generates a righting moment that automatically rights the bicycle when stationary.

[0032] Optionally, a righting weight is provided inside one of the wheel housings. Optionally, a righting weight is provided in each of the two wheel assemblies.

[0033] 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.

[0034] If necessary, a counterweight is arranged below the height of the axis.

[0035] If necessary, a righting weight is attached to the frame in the lower area, particularly in the lower third or lower quarter, of the bicycle.

[0036] 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.

[0037] If applicable, a seat or saddle is provided, and the bicycle is designed as a child's balance bike.

[0038] Preferably, the frame extends to below the height of the wheel hub(s) or axles of one or both wheel assemblies. 65220 / GP / -

[0039] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0040] Preferably, an erection weight is provided in this area of ​​the frame and is particularly attached in or to the frame.

[0041] Where appropriate, the frame and in particular other components of the bicycle, such as the handlebars or the seat, are designed or assembled from lightweight components such as aluminum hollow profiles, plastic hollow bodies, foamed plastic parts and / or fiber-reinforced plastic parts.

[0042] If necessary, the curve sections are designed to enable stable inclined cornering with a curve radius that depends on the angle of inclination around the longitudinal axis.

[0043] If necessary, it is provided that the lowest point of the wheel arrangement, which is also the contact area with the ground, lies in one of the curve areas when cornering at an angle.

[0044] If necessary, the straight-line running area is provided for as a central, flattened or clear section of the tire contour, forming a contact area for stable upright positioning of the bicycle.

[0045] 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.

[0046] 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.

[0047] If necessary, the straight-line section may have a transition area on each side, forming a smooth or rounded transition to the adjacent curved section. 65220 / GP / -

[0048] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0049] The bicycle is preferably designed in such a way that it can be ridden using essentially the same technique as a conventional walking or cycling 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 bicycle's center of gravity.

[0050] The basic design can correspond to that of a conventional bicycle. Preferably, it includes a frame, two wheel assemblies (a front wheel assembly and a rear wheel assembly), and a steering mechanism for the front wheel assembly. The rear wheel assembly is preferably unsteered. The steering mechanism preferably forms part of the frame. Preferably, the bicycle comprises exactly two wheel assemblies.

[0051] Both wheel configurations preferably feature a convexly curved tire profile. This curved tire profile allows the bicycle 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 bicycle's tilt angle.

[0052] At the same time, the tire contour is also designed in such a way that the bicycle, especially according to the self-righting toy principle, automatically rights itself when stationary.

[0053] If the stationary bicycle is tilted sideways around a longitudinal axis from an upright position, it will automatically right itself when released.

[0054] This kinematic effect is achieved in particular by designing the tire contour in such a way that a lateral tilt of the bicycle 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, thereby allowing gravity to automatically right the bicycle. 65220 / GP / -

[0055] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0056] 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, the point of contact between the wheel and the ground moves along the tire's contour into the curved section of the wheel assembly. 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.

[0057] Preferably, the curvature of the tire contour in the area of ​​the lowest point of the wheel assembly, which is also the contact area with the ground, defines a local center of curvature in every tilting position of the bicycle about the longitudinal axis within lateral tilting angle limits, and optionally the tire contour is designed such that in every tilting position of the bicycle between the tilting angle limits, the local center of curvature is higher than the center of gravity of the bicycle in this tilting position, whereby gravity automatically rights the bicycle when stationary, in particular according to the self-righting principle.

[0058] It is advantageous if the bicycle's center of gravity is as low as possible. The lower the bicycle's 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 bicycle into a turn.

[0059] 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 wheel assembly.

[0060] According to one possible embodiment, the bicycle has a wheelbase of approximately 350 to 500 mm. 65220 / GP / -

[0061] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0062] According to this or another embodiment, the radius of curvature of the average curvature of the tire contour of the wheel assembly is between 120 mm and 180 mm, preferably approximately 150 mm.

[0063] The required radius of curvature of the tire contour depends in particular on the position of the bicycle'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.

[0064] The wheel can, for example, have a diameter of 150 to 200 mm, for example 175 mm.

[0065] 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.

[0066] 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.

[0067] In all embodiments, the straight-ahead running area can form a central, cylindrical or slit-shaped section of the wheel arrangement.

[0068] Preferably, in all embodiments, the tire contour has a convex curved shape to enable stable, inclined cornering.

[0069] 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 to which the tire contour consequently approximates 65220 / GP / -

[0070] Woom GmbH, Muthgasse 109a, 1190 Vienna (AT) certain deviations may occur. For example, an arithmetic mean of the curvature of the tire contour can be used for the calculation. Deviations caused by a tire profile or a gap in the wheel arrangement should be disregarded.

[0071] 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 bicycle. The position of the center of gravity can then be defined by a perpendicular distance from this axis to the tire contour.

[0072] The wheel arrangements 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.

[0073] 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.

[0074] For example, the righting weight can be located in or at the bottom of the frame.

[0075] Alternatively or additionally, a righting weight can be arranged on one or both wheel assemblies. For example, a weight can be attached to the axle of one of the wheel assemblies and extend downwards from this axle when the bicycle is upright. For example, the axle is rigidly arranged, and the wheel assembly can be rotatably mounted to this rigid axle via a bearing of 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 on the front wheel assembly and / or on the rear wheel assembly. 65220 / GP / -

[0076] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0077] The wheel assembly may include a gap or interior space, and the righting weight may be located within this gap or interior space. Alternatively, the righting weight may be attached to the wheel assembly, for example, to a fixed hubcap.

[0078] 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.

[0079] 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.

[0080] The function of automatically righting the bicycle from a tilted position when stationary is preferably limited to certain tilt angle limits. This makes it possible to lay the bicycle flat on its side without it automatically righting itself. Furthermore, this allows the bicycle's center of gravity to be positioned somewhat higher or a less massive righting weight to be used, thus simplifying the design. The tilt angle limits within which the bicycle 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 bicycle about a longitudinal axis.

[0081] The frame of the bicycle can, for example, be made of aluminum tubes.

[0082] The seat can, for example, be formed from a hollow body made of a solid plastic such as EPP or PP.

[0083] The retaining elements for mounting the wheel assemblies can be part of the frame and / or made of aluminum hollow profiles or also of a lightweight construction made of 65220 / GP / -

[0084] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0085] It may be formed from plastic, such as glass fiber reinforced plastic, such as glass fiber reinforced polypropylene.

[0086] The wheel assembly can comprise a rigid base body or rim and soft, elastic treads. In this case, the treads also form 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 line from the centrally located straight-line running zone towards the tire shoulders.

[0087] The base body or rims can be designed as hollow or lightweight structures and made, for example, from a rigid plastic such as polypropylene, PVC, or similar materials. The tread can be made, for example, from an elastic or soft material such as EVA.

[0088] In principle, it can be advantageous to make all components above the center of gravity, or all components except for a righting weight, from lightweight materials.

[0089] Lightweight materials can include, for example, hollow profiles made of aluminum, lightweight structures made of fiber-reinforced plastic, or hollow plastic bodies.

[0090] The righting weight is preferably a body connected to another component, preferably the frame and / or a wheel assembly or its axle. The righting weight is preferably made of a different material than the frame or the wheel assembly. 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.

[0091] 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, when tilted laterally about its longitudinal axis, does not automatically right itself outside the tilt angle limits. This allows the wheels 65220 / GP / -

[0092] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) and all components except the handlebars should be narrow, for example to fulfill the function of a child's balance bike.

[0093] 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.

[0094] 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.

[0095] The invention will be further described using the figures.

[0096] Fig. 1 shows a schematic oblique view of a possible embodiment of a bicycle.

[0097] Fig. 2 shows a schematic representation of the kinematic relationships of a bicycle.

[0098] Fig. 3 shows a schematic side view of an embodiment of a bicycle, in particular the embodiment from Figure 1.

[0099] Fig. 4 shows a schematic sectional view of a bicycle in the area of ​​a wheel assembly.

[0100] Unless otherwise specified, the reference symbols in the figures correspond to the following components:

[0101] Frame 1, longitudinal axis 2, front wheel arrangement 3, rear wheel arrangement 4, steering 5, center of gravity 6, center of gravity axis 7, tire contour 8, contact point 9, straight-line running area 10, cornering area 11, radius of curvature 12, normal distance 13, 65220 / GP / -

[0102] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0103] Tilt angle limit 14, righting weight 15, gap 16, axle 17, wheel hub 18, transition area 19, retaining element 20.

[0104] Fig. 1 shows a schematic oblique view of a bicycle. The bicycle comprises a frame 1 and two wheel assemblies 3, 4 arranged along the longitudinal axis 2, in particular a front wheel assembly 3 and a rear wheel assembly 4. In all embodiments, the bicycle is preferably designed as a substantially single-track bicycle. The two wheel assemblies 3, 4 are therefore arranged centrally one behind the other along the longitudinal axis 2 and are preferably rotatably mounted on the frame.

[0105] The front wheel assembly 3 is steerable via a steering mechanism 5. The rear wheel assembly 4 is preferably unsteered, meaning that the axle 17 of the rear wheel assembly 4 is essentially rigidly arranged relative to the frame 1.

[0106] In this embodiment, the wheel assemblies 3, 4 are divided, each comprising two wheel shells 3', 3", 4', 4". The wheel assemblies 3, 4 are each divided along a normal plane of the axle 17, with the division preferably running centrally.

[0107] A gap 16 is preferably kept free between the wheel cups 3', 3", 4',4".

[0108] The frame 1 comprises two retaining elements 20, which are designed to hold the wheel assemblies 3, 4. In conventional bicycles, this retaining element 20 is the fork or the seat stay and chain stay. In the present embodiment, however, this retaining element 20 is arranged centrally and projects through the respective gap 16 into the wheel assemblies 3, 4.

[0109] This is particularly evident in Figures 3 and 4.

[0110] The wheel housings 3', 3", 4', 4" can each be rotatably connected to one another or arranged to rotate freely relative to each other. If the two wheel housings 3', 3", 4', 4" are rotatably connected to one another, then both wheel housings 3', 3", 4', 4" of a 65220 / GP / - always rotate.

[0111] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0112] The wheel arrangement 3, 4 travels at the same speed, even if the point of contact 9 is located in the curve area 11 during cornering, and thus only one of the wheel shells 3', 3", 4', 4" touches the ground. Alternatively, the two wheel shells 3', 3", 4', 4" can also be rotated essentially freely relative to each other, so that the two wheel shells can each have a different speed.

[0113] The gap 16 preferably forms at least part of the straight-running area 10.

[0114] The configuration in which a retaining element 20 projects into a central gap 16 can be provided for one of the wheel arrangements 3, 4 or for both wheel arrangements 3, 4.

[0115] All components of the bicycle 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.

[0116] At least one of the wheel assemblies 3, 4, or in the present embodiment both wheel assemblies 3, 4, has a convexly curved tire contour 8. When the bicycle 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 bicycle 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 shoulder.

[0117] 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.

[0118] The tire contour 8 enables stable cornering, during which the bicycle is tilted about a longitudinal axis 2. The turning radius is preferably dependent on the tilt angle of the bicycle about the longitudinal axis 2. 65220 / GP / -

[0119] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0120] In addition, the tire contour 8 is designed in all embodiments such that the bicycle, 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.

[0121] 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.

[0122] In other words, the tire contour is designed in such a way that a lateral tilting of the bicycle 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.

[0123] The bicycle preferably includes a steering rod of the steering system 5, with which manual steering can be carried out.

[0124] In all embodiments, the bicycle can include a seat that projects from the frame 1, so that the bicycle, as in the present embodiment, is designed as a balance bike. Alternatively, it is also possible to equip the bicycle 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 bicycle is designed as a scooter or kick scooter. In a scooter embodiment, the steering 5 or the head tube of the bicycle can be longer to form a conventional scooter configuration.

[0125] 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 65220 / GP / -

[0126] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0127] Wheel arrangements 3,4 reduce the impact during starting and braking, thus improving the agility of the bicycle.

[0128] Figure 2 describes in more detail the kinematic conditions for achieving the self-righting effect. Two positions are shown in particular. In a first position, the point of contact 9 lies within the straight-line running area 10 of the tire contour 8. This is, for example, a position in which the bicycle is upright. The center of gravity 6 and the center of gravity axis 7 projected in this illustration are located centrally above the straight-line running area 10. In all embodiments, the straight-line running area 10 is preferably a centrally located, flattened section of the tire contour 8, which is intended to enable a stable central position of the bicycle.

[0129] 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.

[0130] 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.

[0131] If the bicycle is now tilted to the side, the point of contact 9' with the ground is located in the curve area 11'. Tilting the bicycle naturally also moves the center of gravity 6 and the center of gravity axis 7. 65220 / GP / -

[0132] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0133] 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 bicycle 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 bicycle automatically rights itself according to the principle of a self-righting toy. The same process occurs analogously when the bicycle is tilted to the other side.

[0134] When the bicycle is tilted about a longitudinal axis 2 from its neutral position, the center of gravity 6 or the center of gravity axis 7 is also preferably raised due to the special design of the tire contour 8. This also causes a restoring moment and the bicycle to right itself.

[0135] According to the present configuration, this effect can be used within two tilt angle limits 14', 14". If the bicycle is moved beyond a tilt angle limit 14", the center of gravity also moves beyond the vertical of the point of contact 9, and the bicycle can tip over.

[0136] Fig. 2 is not an exact scale kinematic representation, i.e., the angles and lengths may be distorted.

[0137] Fig. 3 shows a schematic side view of a possible embodiment of a bicycle, in particular the bicycle 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 area of ​​the bicycle, 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 area of ​​the front wheel assembly 3, in the area of ​​the rear wheel assembly 4, and / or in the lower area of ​​the frame 1. In the present embodiment, these three possibilities for the placement of the righting weights 15 are shown in Figure 65220 / GP / -

[0138] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) is shown, whereby any combination of the placement of erection weights 15 is also possible.

[0139] The frame 1 or its steering 5 comprises at least one retaining element 20 on which a wheel arrangement 3, 4 or its axle 17 is attached or mounted.

[0140] In the present embodiment, the two retaining elements 20 project into the front wheel assembly 3 and into the rear wheel assembly 4. In particular, as also shown in Fig. 1, a gap 16 is provided for each wheel assembly 3, 4.

[0141] Preferably, the erection weight 15 is rigidly or immovably connected to the frame 1 or its steering and in particular to the retaining element 20.

[0142] If the righting weight 15 is located in the area of ​​a wheel assembly 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 located below the axle 17 or the wheel hub 18. Arranging the righting weight 15 in the area of ​​the wheel assemblies 3, 4 is advantageous because the wheel assembly 3, 4 is the element of the bicycle that extends furthest downwards. For this reason, the righting weight 15 can extend particularly far downwards in the area of ​​the wheel assemblies 3, 4 and thus shift the center of gravity 6 downwards particularly effectively.

[0143] 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 bicycle 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 wheel assemblies 3 and 4. 65220 / GP / -

[0144] Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT)

[0145] In all embodiments, the frame 1 can be partially formed by the erection weight 15.

[0146] Fig. 4 shows a schematic sectional view in the area of ​​the front wheel arrangement 3. In principle, this design can also be provided for, or only for, the rear wheel arrangement 4.

[0147] The frame 1, or rather its steering mechanism 5, includes a retaining element 20. The retaining element is designed to hold the axle 17. The axle 17 can either be rigidly attached to the retaining element 20, and the wheel assembly 3 has a mounted wheel hub 18 that runs on this axle 17, so that the

[0148] The wheel assembly 3 can rotate. In the present configuration, however, the axle 17 is rotatably mounted on the retaining element 20. The wheel hub 18 and the axle 17 can therefore be considered as a single element. The retaining element 20 is preferably rigidly connected to the frame or its steering 5.

[0149] The wheel assembly 3 includes a gap 16. The retaining element 20 projects into this gap 16. The gap 16 is preferably arranged centrally and runs along a normal plane of the axle 17.

[0150] The two wheel shells 3', 3" can be coupled or rotatably connected to each other. Alternatively, the two wheel shells 3', 3" can be arranged to rotate relative to each other, so that, for example, one of the wheel shells 3', 3" can remain stationary while the other wheel shell rotates.

[0151] The two wheel cups 3', 3" together form the tire contour 8, as can also be seen, for example, in Figures 1 and 2. The tire contour 8 comprises a straight-running area 10 and curved areas 11 arranged on both sides of this straight-running area 10.

[0152] In the configuration according to Fig. 4, the righting weight 15 can be provided in an interior space of the wheel assembly 3. In particular, the righting weight 15 can be attached to the retaining element 20. The righting weight 15 is preferably located below 65220 / GP / -

[0153] Woom GmbH, Muthgasse 109a, 1190 Vienna (AT) of the axis 17 attached to the retaining element 20. This allows the righting weight 15 to be positioned at a low point and thus efficiently lower the center of gravity.

[0154] Optionally, the retaining element 20 is a continuous part that, when the bicycle is upright, extends from an upper area through the gap 16 to the lower area of ​​the wheel assembly 3. The righting weight 15 can then be provided in the lower area, and this righting weight 15 can be part of the retaining element 20 or a separate part connected to the retaining element.

[0155] The wheel arrangement 3, in particular its wheel shells 3', 3", preferably comprises a soft running surface.

[0156] The design of the wheel arrangement 3 can be used, for example, in the embodiments of Figures 1, 2 and 3 for the front wheel arrangement 3 and / or for the rear wheel arrangement 4.

[0157] The wheel cups 3', 3", 4', 4" are preferably rounded or flattened at their end edges in the area of ​​the gap 16. These end edges form two annular contact areas when the bicycle is upright. The edges or the gap form the straight-line running area 10. If necessary, the edges also form the transition areas 19 and thus the continuous or rounded transitions to the adjacent curve areas 11.

Claims

65220 / GP / - Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) Patent claims 1. Bicycle for children, especially children's balance bike, including: - a frame (1 ), - two wheel assemblies (3, 4) attached centrally one behind the other along a longitudinal axis (2) of the bicycle parallel to the ground on the frame (1) - and a steering mechanism (5) for steering the front wheel assembly (3), - wherein all components of the bicycle 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 arrangement (4), preferably both wheel arrangements (3, 4), have a convexly curved tire contour (8) along which, depending on the lateral inclination of the bicycle 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 bicycle, 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. Bicycle for children, especially children's balance bike, including: - a frame (1 ), - two wheel assemblies (3, 4) attached centrally one behind the other along a longitudinal axis (2) of the bicycle parallel to the ground on the frame (1) - and a steering mechanism (5) for steering the front wheel assembly (3), - wherein all components of the bicycle have a common center of gravity (6) and a center of gravity axis (7) running parallel to the longitudinal axis (2) 65220 / GP / - Woom GmbH, Muthgasse 109a, 1190 Vienna (AT) define, - wherein at least the rear wheel arrangement (4), preferably both wheel arrangements (3, 4), have a convexly 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 bicycle 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 bicycle when stationary, in particular according to the self-righting toy principle.

3. Bicycle according to claim 1 or 2, characterized in that the tilt angle limits (14', 14") measured from the upright position of the bicycle about the longitudinal axis (2), within which the bicycle 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. Bicycle according to one of claims 1 to 3, characterized in that, - that the bicycle 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 bicycle is tilted 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 bicycle, generates a righting moment which automatically rights the bicycle when stationary.

5. Bicycle according to claim 4, characterized in that an axle (17) is provided on which one of the wheel arrangements (3, 4) is rotatably mounted.

6. Bicycle according to one of claims 4 or 5, characterized in that a righting weight (15) is arranged below the height of the axle (17). 65220 / GP / - Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) 7. Bicycle according to one of claims 4 to 6, characterized in that, - that at least one of the wheel arrangements (3, 4), preferably both wheel arrangements (3, 4), is divided along a normal plane of the axle (17) and comprises two lateral wheel shells (3', 3", 4', 4") arranged side by side, which together form the tire contour (8).

8. Bicycle according to claim 7, characterized in that, - that a gap (16) is kept free between the wheel shells (3', 3", 4', 4"), - wherein the gap width is preferably less than 5cm, particularly preferably less than 3cm.

9. Bicycle according to claim 8, characterized in that the retaining element (20) of the frame (1 ) or of the steering (5), on which the wheel arrangement (3, 4) is held or mounted, projects into the gap (16) and is connected there, in particular, to the axle (17).

10. Bicycle according to one of claims 4 to 9, characterized in that the righting weight (15) is arranged in the gap (16).

11. Bicycle according to one of claims 9 or 10, characterized in that the righting weight (15) is rigidly arranged on the retaining element (20).

12. Bicycle according to one of claims 4 to 11, characterized in that a righting weight (15) is attached in the lower area, in particular in the lower third or lower quarter, of the bicycle, in or on the frame (1).

13. Bicycle according to one of claims 4 to 12, characterized in that the righting weight (15) has a density greater than 3 g / cm³ 3 , preferably greater than 6 g / cm² 3 exhibits.

14. Bicycle according to one of claims 1 to 13, characterized in that a seat or saddle is provided, and that the bicycle is designed as a child's balance bike. 65220 / GP / - Woom GmbH, Muthgasse 109a, 1 190 Vienna (AT) 15. Bicycle according to one of claims 1 to 14, characterized in that the frame extends to below the height of the wheel hub(s) (18) or the axles (17) of one or both wheels (3, 4).

16. Bicycle according to one of claims 1 to 15, characterized in that the frame (1 ) and in particular also other components of the bicycle 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.

17. Bicycle according to one of claims 1 to 16, 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), - 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.

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