Model vehicle with spring energy storage

Abstract

Model vehicle (2), comprising - a chassis (4), - a spring energy storage device (90) attached to the chassis (4) comprising a spring (92), in which energy for propulsion of the model vehicle (2) can be stored by winding up the spring (92), - at least two driven wheels (8; 8a, 8b) rigidly mounted on a common first axis of rotation (6) and arranged laterally on two opposite sides (2a, 2b) of the model vehicle (2), wherein the first axis of rotation (6) is rotatably mounted on the chassis (4), - means for converting at least part of the energy stored in the spring energy storage device (90) into a rotational movement of the first rotational axis (6) and the driven wheels (8; 8a, 8b) in order to propel the model vehicle (2) on a surface when at least one of the driven wheels (8; 8a, 8b) is in contact with the surface and there is sufficient static friction between the at least one driven wheel (8; 8a, 8b) and the surface, and - at least one further wheel (12) rotatable about a second axis of rotation (10), wherein the second axis of rotation (10) is rotatably mounted on the chassis (4) at a distance from the first axis of rotation (6), characterized in that the model vehicle (2) has means (26) which are designed to selectively reduce static friction between a driven wheel (8a) arranged on a first side (2a) of the model vehicle (2) and the ground, while static friction between another driven wheel (8b) arranged on the other side (2b) of the model vehicle (2) and the ground remains largely unchanged.

Description

[0001] The present invention relates to a model vehicle comprising: - a chassis, - a spring energy storage device attached to the chassis with a spring in which energy for propulsion of the model vehicle can be stored by winding up the spring, - at least two driven wheels mounted on a common first axis of rotation and arranged laterally on the model vehicle, wherein the first axis of rotation is rotatably mounted on the chassis, - means for converting at least part of the energy stored in the spring energy storage device into a rotational movement of the first rotational axis and the driven wheels in order to propel the model vehicle on a surface when at least one of the driven wheels is in contact with the surface and there is sufficient static friction between the at least one driven wheel and the surface, and - at least one further wheel rotatable about a second axis of rotation, wherein the second axis of rotation is rotatably mounted on the chassis at a distance from the first axis of rotation.

[0002] Pull-back or wind-up model vehicles in various designs are known from the prior art. One example is described in US 2022 297 019 A1.

[0003] The acceleration and top speed of the model vehicle are influenced, among other things, by static friction between the running surfaces of the driven wheels and the ground. Static friction between two parts is a force that occurs when the surfaces of the two parts are in contact and "cling" to each other due to microstructures, roughness, and other factors. Normally, the static friction force should not be exceeded when accelerating the model vehicle, so that the wheels not only glide over the ground but also provide propulsion. The formula for calculating static friction is: FLift=μLift⋅N

[0004] Where F Haft the static friction force, µ Haft the coefficient of static friction (dimensionless number that reflects the friction properties of the surfaces) and N the normal force acting perpendicular to the surface.

[0005] It is important to note that static friction represents a maximum frictional force, and the driven wheels and the ground move relative to each other when the frictional force is overcome. If the applied force exceeds this maximum static frictional force, sliding friction occurs, and the parts move relative to each other, resulting in undesirable spinning of the driven wheels on the ground to achieve high acceleration values and top speeds. It is conceivable to manufacture and sell various model vehicles with differently designed treads (e.g., material, surface structure, etc.) for the driven and free-wheeling wheels. Alternatively, replacement wheels with differently designed treads can be offered and sold for retrofitting the model vehicle.Finally, it would also be conceivable to offer and sell differently designed treads for attachment to the wheels. The treads, wheels, or model vehicles can be designed for use on different types of surfaces, allowing the model vehicle to achieve a desired level of longitudinal and lateral acceleration.

[0006] Based on the described prior art, the present invention is based on the object of designing and developing a model vehicle of the type mentioned at the outset such that it can be enabled, in the simplest possible way and in particular without changing the treads or wheels, to travel not only on any desired first track but also on a very tight circular track (so-called donuts). The diameter of the desired donut is significantly smaller than a turning circle of the model vehicle with normally turned steerable wheels during normal cornering. In particular, the diameter of the donut is less than half the turning circle of the model vehicle during normal cornering. Preferably, the at least one further wheel rotatable about the second axis of rotation has a movement component transverse or oblique to a rolling direction of the at least one wheel about the at least one second axis of rotation during donut travel.

[0007] To achieve this object, a model vehicle having the features of claim 1 is proposed. In particular, starting from the model vehicle of the type mentioned at the outset, it is proposed that the model vehicle comprise means configured to selectively reduce static friction between a driven wheel arranged on a first side of the model vehicle and the ground, while static friction between another driven wheel arranged on the other side of the model vehicle and the ground remains largely unchanged.

[0008] According to the invention, use is made of the fact that when the model vehicle is driven via the driven wheels on both sides of the model vehicle, i.e. when the propulsion via the driven wheels on both sides of the model vehicle is largely uniform, the model vehicle travels on any desired first path. The type or course of the first path depends on a steering angle with which the at least one further wheel, which is freely rotatable about the second axis of rotation, is turned in the plane of the surface extension of the chassis. With a steering angle of 0°, i.e. at least one further wheel is not turned, or there is no steering function, the first path is designed as a straight line, so that the model vehicle travels straight ahead. With a steering angle of ≠0°, the first path is designed as a more or less large curve in any desired direction, i.e. the model vehicle travels on any desired curved path.The steering angle can be fixed in direction and magnitude before the model vehicle begins propulsion and remain constant during propulsion. In this case, the initial trajectory would be a circular trajectory. However, the steering angle can also be dynamically varied in direction and magnitude during propulsion, so that the initial trajectory can be an ellipse, a figure-8 curve, an S-curve, or any other variable curved trajectory.

[0009] With reduced static friction between the driven wheel and the ground on the first side of the model vehicle, propulsion of the model vehicle is achieved primarily on one side via the driven wheel located on the opposite second side of the model vehicle, so that the model vehicle negotiates a tight curve or a donut toward the first side of the model vehicle. In this sense, it is proposed that the static friction between the running surface of the driven wheel located on the second side and the ground be sufficiently large to ensure sufficient propulsion of the model vehicle on the ground, even with reduced static friction on the first side.

[0010] The model vehicle according to the invention can therefore be switched between driving on a first track (straight ahead or on any curved track), the course of which is determined by a steering angle of the wheels freely rotatable about the second axis of rotation, and driving on particularly tight curves, so-called donuts, where the freely rotatable wheels preferably have a movement component transversely or obliquely to their rolling direction about the second axis of rotation.

[0011] The driven wheels arranged on the side of the model vehicle can protrude laterally beyond the chassis or the model vehicle or its body, or can be arranged in wheel arches that are formed laterally in the chassis or in the body, so that they do not protrude laterally beyond the chassis or the model vehicle or its body.

[0012] The model vehicle can have the shape and design of a tricycle (e.g. Ape Car from Piaggio), a two- or multi-axle car or any other two- or multi-axle motor vehicle (e.g. truck, bus, tractor, construction vehicle, lunar rover, etc.).

[0013] The at least one wheel rotatable about the second axis of rotation is preferably a non-driven or freely rotating or free-running wheel. The second axis of rotation runs parallel to the first axis of rotation when the model vehicle is traveling straight ahead. Preferably, each non-driven wheel has its own second axis of rotation. The at least one second axis of rotation preferably extends in a plane that runs essentially parallel to a surface extension of the chassis. It is conceivable that the at least one second axis of rotation can be steered about a steering axis in this plane. The at least one steering axis preferably runs perpendicular to the surface extension of the chassis or slightly obliquely thereto.

[0014] If the static friction between the driven wheels arranged on both sides of the model vehicle or their running surfaces and the ground is the same and sufficiently large for propulsion, the model vehicle travels on a straight line or any curved path, depending on how the at least one second axis of rotation is aligned in the plane of the surface extension of the chassis, i.e. depending on the direction in which the wheels that are freely rotatable about the second axis of rotation are directed.

[0015] The axes of rotation can be rotatably mounted directly or indirectly on the chassis. For example, the spring energy storage device can be part of a drive block of the model vehicle, which is attached to the chassis and from which ends of the first axis of rotation protrude at the sides, to which the driven wheels are rigidly attached. Inside the drive block, a central section of the first axis of rotation between the protruding ends can be coupled to the spring of the spring energy storage device. This would mean that the first axis of rotation would be rotatably mounted on the chassis indirectly via the drive block. The one or more second axes of rotation can be rotatably mounted on the chassis indirectly via a steering linkage, for example. The wheels guided on the second axes of rotation can be steered by the steering linkage, so that the model vehicle can corner while simultaneously propelling itself along the ground. The steering angles orThe curves can be static (preset before the model vehicle is driven) or dynamic (changeable as the model vehicle moves along the ground). It would also be conceivable for one or more of the pivots to be indirectly mounted on the chassis via a spring rod. The spring rod allows the pivot or a part of the pivot to be vertically movable, thus providing suspension for the wheels mounted on it.

[0016] Preferably, the static friction between the running surface of the at least one non-driven or free-running wheel of the model vehicle and the ground should be significantly lower than the static friction between the driven wheel arranged on the second side, preferably so low that sliding friction occurs, so that the at least one free-running wheel can roll or slide over the ground not only in the direction of travel of the model vehicle, but also with a transverse component to the direction of travel. This facilitates or enables the model vehicle to drive on particularly tight curves (so-called donuts), which have a smaller diameter than the turning circle of the model vehicle.

[0017] Reducing the static friction between the driven wheel arranged on the first side and the ground can be achieved in various ways. For example, it would be conceivable to introduce a lubricant, such as a liquid, particularly oil or water, between the running surface of the driven wheel arranged on the first side and the ground to reduce static friction.

[0018] However, it is particularly preferred if the means for reducing static friction are designed to raise the driven wheel arranged on the first side of the model vehicle, preferably completely off the ground. Thus, the driven wheel arranged on the first side is pressed onto the ground with less force, if at all, so that static friction is reduced. The driven wheel arranged on the first side can be raised, for example, by laterally raising the first rotational axis on the first side of the model vehicle.

[0019] However, according to a preferred embodiment of the invention, it is proposed that the means for reducing the static friction comprise a spacer element that is laterally movable on an underside of the chassis between a retracted position and an extended position, wherein the spacer element is arranged closer to the driven wheel arranged on the first side of the model vehicle and further away from the other driven wheel arranged on the other side of the model vehicle and, in its retracted position on both sides of the model vehicle, enables contact of the driven wheels with the ground and sufficient static friction between the driven wheels and the ground and, in its extended position, comes into contact with the ground and lifts the chassis laterally,so that there is less static friction between the driven wheel arranged on the first side of the model vehicle and the ground, while the static friction between the driven wheel arranged on the other side of the model vehicle and the ground remains largely unchanged.

[0020] According to this embodiment, use is made of the fact that when the model vehicle is driven via the driven wheels arranged on both sides, with the spacer element retracted, the model vehicle travels on the first path (straight ahead or on any curved path). When the spacer element is extended and arranged near or on the first side of the model vehicle, the model vehicle is driven primarily via a second wheel arranged on the side of the model vehicle on the opposite second side of the model vehicle, so that the model vehicle can negotiate a tight curve or a so-called

[0021] Donut moves toward the first side of the model vehicle. In this sense, it is suggested that the static friction between the running surface of the second driven wheel and the ground be sufficiently large to ensure adequate propulsion on the ground, even with the spacer element extended.

[0022] The first wheel raised by the extended spacer element has lower static friction with the ground than the second wheel which is in normal contact with the ground, or may even be completely lifted off the ground. The lower static friction results at least in part from the lifting or lifting of the first wheel off the ground. This reduces the contact force with which the first wheel presses against the ground, preferably even to zero. If there is still slight contact between the first wheel and the ground when the spacer element is extended, the lower static friction can be supported by a different material or a different design of the tread of the first wheel compared to the tread of the second wheel.

[0023] It would be conceivable for the model vehicle to have a movable spacer element on each of the two opposite sides of the chassis, with the first spacer element positioned closer to a first of the driven wheels and further away from the second driven wheel, and the other spacer element positioned closer to the second driven wheel and further away from the first driven wheel. In their retracted positions, the two spacer elements on both sides of the model vehicle enable contact of the driven wheels with the ground and uniform propulsion of the vehicle on both sides.When (with the second spacer element retracted) the first spacer element in its extended position comes into contact with the ground, the chassis is lifted laterally on the first side on which the first driven wheel is arranged, so that there is less static friction between the first driven wheel and the ground, while the static friction between the second driven wheel and the ground remains largely unchanged, so that the model vehicle drives a tight curve towards the first side of the model vehicle.Conversely, when the second spacer element in its extended position comes into contact with the ground (with the first spacer element retracted), the chassis is lifted laterally on the second side, where the second driven wheel is located, resulting in lower static friction between the second driven wheel and the ground, while the static friction between the first driven wheel and the ground remains largely unchanged, allowing the model vehicle to make a tight turn toward the second side of the model vehicle. This allows the model vehicle to selectively perform donuts in two opposite directions.

[0024] According to an advantageous development of the invention, it is proposed that the spacer element is movable between the retracted position and the extended position by means of a first switch or button and can be fixed in this position. The switch or button is preferably accessible from the outside and is arranged on the model vehicle so that it can be operated manually by a user of the model vehicle, preferably without tools, e.g., with a finger of the user. The switch or button is preferably arranged on the underside of the model vehicle so that the external appearance of the model vehicle standing or moving on the ground is not impaired. However, an arrangement of the switch or button on the front, rear, or top of the vehicle would also be conceivable.

[0025] Particularly preferably, the switch or button is designed as a slide switch that can be moved between at least two discrete positions. In a first position, the spacer element is retracted, and the model vehicle does not perform donuts, but rather drives straight ahead or in a curve according to a steering angle of the free-running wheels, wherein the diameter of the circular path in this case depends on a steering angle of the free-running wheels. In a second position, the spacer element is extended, and the model vehicle performs donuts, wherein the diameter of the donuts is smaller than a minimum turning circle of the model vehicle. The minimum turning circle is achieved at the maximum steering angle of the free-running wheels.This particularly small diameter of the donuts is achieved by the fact that the one-sided drive of the model vehicle results in a lateral movement component of the free-running wheels on the ground via only one of the two laterally arranged driven wheels. The lateral movement component is preferably directed obliquely or transversely to the rolling direction of the free-running wheels around the second axis(es).

[0026] If the model vehicle has two spacers arranged on opposite sides, a separate switch or button can be provided for each spacer to extend or retract the corresponding spacer and hold it in this position.

[0027] According to a preferred embodiment, however, a common switch or button is provided which alternately extends or retracts both spacer elements and holds them in these positions. In this case, the switch or button is preferably designed as a slide switch which can be adjusted between at least three discrete positions. In a first position, both spacer elements are retracted and the model vehicle does not do donuts, but rather drives straight ahead or in a curve according to a steering angle of the free-running wheels, wherein the diameter of the circular path in this case depends on a steering angle of the free-running wheels. In a second position, a first spacer element is extended while the other spacer element is retracted, and the model vehicle drives donuts in a first direction, wherein the diameter of the donuts is smaller than a minimum turning circle of the model vehicle.In a third position, the second spacer element is extended while the other spacer element is retracted, and the model vehicle drives donuts in a second direction opposite to the first direction, whereby here too the diameter of the donuts is smaller than a minimum turning circle of the model vehicle.

[0028] According to an advantageous development of the present invention, it is proposed that the spacer element, at a distal end in its extended position, has a sliding element which is made of a material and / or shaped to slide over the surface with the lowest possible static friction. The sliding element preferably has an underside made of a hard material, such as a hard plastic or metal, so that it can slide particularly well over a smooth surface made of various materials. The surface can be, for example, a room floor or a surface of a piece of furniture, e.g. a table, a worktop or the like. It consists, for example, of a hard material, e.g. earthenware, tiles, granite, marble, wood, parquet, laminate, linoleum or similar. The underside of the sliding element is preferably smooth. It is particularly preferred if the sliding element is rounded or skid-shaped.The longitudinal extension of the runner preferably runs parallel to a direction in which the sliding element glides over the ground.

[0029] According to a preferred embodiment, the spacer element has, at a distal end in its extended position, a roller element which is mounted so as to be rotatable about a rolling axis and is designed to roll along the surface when the spacer element comes into contact with the surface. The rolling element facilitates the gliding of the distal end of the spacer element over the surface. The rolling axis preferably runs transversely to a direction in which the rolling element rolls over the surface. The rolling element or a rolling surface of the rolling element can be made of a hard material, e.g. a hard plastic or metal. However, the rolling surface can also be made of a softer material, e.g. a softer plastic, rubber or silicone. Thanks to the rolling element, the distal end of the spacer element can glide or roll not only over a hard surface, but also over a soft surface, e.g. carpets, rugs or similar.Furthermore, thanks to the rolling element, the distal end can also glide or roll over smaller unevenness in the surface, e.g. joints between earthenware, tiles or slabs, grooves between wooden floorboards.

[0030] According to another embodiment, the spacer element has a rotatably mounted ball element at a distal end in its extended position, which is designed to roll on the surface when the spacer element comes into contact with the surface. The ball element facilitates the gliding of the distal end of the spacer element over the surface. The ball element or a rolling surface of the ball element can be made of a hard material, e.g. a hard plastic or metal. However, the rolling surface can also be made of a softer material, e.g. a softer plastic, rubber or silicone. Thanks to the ball element, the distal end of the spacer element can glide or roll not only over a hard surface, but also over a soft surface, e.g. carpets, rugs or similar. Furthermore, thanks to the ball element, the distal end can also roll over minor unevenness in the surface, e.g.Joints between stoneware, tiles, or slabs, and grooves between wooden floorboards, slide or roll over. One advantage of the ball element is that it can rotate not only around a fixed axis, but in any direction.

[0031] According to an advantageous development of the present invention, it is proposed that the spring energy storage device can be wound up by means of a key or by pulling back the model vehicle, wherein when the model vehicle is pulled back, the driven wheels of the model vehicle are in contact with the ground, so that they execute a rotary movement together with the first axis of rotation to which they are non-rotatably attached. The rotary movement of the first axis of rotation when pulled back is directed opposite to the direction of rotation it executes when the model vehicle is propelled forward and consequently leads to a winding or tensioning of the spring of the spring energy storage device. As soon as the driven wheels are released with the spring wound up, the wheels rotate, driven by the energy stored in the spring. When the model vehicle is placed on the ground with its driven wheels, the vehicle moves forward.

[0032] Depending on the driving mode of the model vehicle, the forward travel can be straight ahead (the freely rotating wheels of the model vehicle are pointing straight ahead), along a curved path (the freely rotating wheels are turned by a statically predetermined steering angle or one that changes dynamically during forward travel) or driving a donut (the distal end of the spacer element rests on the ground and lifts one of the driven wheels on one side of the model vehicle).

[0033] To enable the model vehicle to also travel on a curved path, it is proposed that the at least one further wheel which can be rotated about the second axis of rotation can be steered about a steering axis, wherein the steering axis runs obliquely, transversely or skewed to the second axis of rotation. Traveling on a curved path is characterized in that a curve radius is largely determined by a steering angle of the steerable wheels. If the static friction between the tread of the steerable wheels and the ground is optimal (i.e. there is no sliding friction), the curve radius is predetermined by the steering angle of the steerable wheels. A steering direction or a steering angle of the at least one steerable wheel can be statically predetermined before the model vehicle actually moves forward, so that it remains constant during forward travel.Alternatively, it would also be conceivable for the steering direction and / or steering angle of at least one steerable wheel to change dynamically as the model vehicle moves forward. The dynamic change in the steering direction or angle can occur over time, depending on the distance traveled by the model vehicle during forward travel, or even randomly.

[0034] Advantageously, the model vehicle comprises means for converting at least a portion of the energy stored in the spring energy storage device into at least one type of steering movement of the at least one wheel freely rotatable about the second axis of rotation, said steering movement changing dynamically during the propulsion of the model vehicle. Therefore, no additional energy source, in particular no electrical energy source (e.g., battery or accumulator), is required to steer the at least one steerable wheel. Furthermore, a separate actuator (e.g., stepper motor or proportional magnet) for moving the steerable wheels about the steering axes can be dispensed with. The steering of the wheels is purely mechanical and is powered by the same spring energy storage device as the forward travel of the model vehicle. The mechanism for steering the wheels can comprise a linkage and / or a gear system.

[0035] The means for converting at least a portion of the energy stored in the spring energy accumulator into a steering movement, and thus the dynamic steering movement of the model vehicle during propulsion, can preferably be activated and / or deactivated by means of a second switch or button. By means of the second switch or button, the forward travel of the model vehicle can thus be switched between cornering and (depending on the position of the first switch or button) travel on the first path (straight ahead or any cornering) or a donut travel. Alternatively or additionally, the second switch can also be designed to set the type of cornering. In this sense, switching could be possible between a statically preset steering angle and a dynamically variable steering angle. Furthermore, it would be conceivable to switch between different types of dynamically variable steering angles.

[0036] It is particularly advantageous if the model vehicle is designed not only to travel on a specific type of curved track, but also to be able to travel on different types of curved tracks. The different types of curved tracks include, for example, - a circular orbit, - an elliptical curved path, - an S-curve track, - a curved track in the shape of a figure eight, or - a meandering curved track.

[0037] Naturally, sliding friction between the running surfaces of the driven and / or steerable wheels and the ground may lead to slight deviations from the specified curved path. This may result, for example, in the starting and end points of a circular path, an elliptical curved path, or a figure-8 path not being exactly the same, in the specified shape of the circular path not being precisely adhered to, and / or in the S-shaped curved path not being fully completed, resulting in an elongated S.

[0038] In this sense, it is proposed that the model vehicle comprise means for converting at least part of the energy stored in the spring energy accumulator into several different types of steering movements that change dynamically during the propulsion of the model vehicle, wherein one of the different types of steering movements can be activated by means of a third switch or button and / or at least one of the types of steering movements can be deactivated by means of the third switch or button. A certain type of steering movement during the forward travel of the model vehicle results in it traveling on a certain curved path. By actuating the third switch or button, the type of curved path on which the model vehicle is to travel can thus be selected.

[0039] It is conceivable that the model vehicle, in order to realize a specific type of steering movement or curved path, has specific means for converting at least a portion of the energy stored in the spring energy storage device into the corresponding steering movement. These means include, for example, rods, gears, or the like. In this case, by actuating the third switch or button, it is possible to switch between the various means for converting at least a portion of the energy stored in the spring energy storage device into the corresponding steering movement, and one of the means for driving on a specific curved path can be selected.

[0040] However, it would also be conceivable for the model vehicle to have switchable means for converting at least part of the energy stored in the spring energy storage device into various steering movements to realize a specific type of steering movement or curved path. These means include, for example, switchable linkages, switchable transmissions, or the like. In this case, the means can be switched by actuating the third switch or button and adjusted so that the model vehicle travels along a specific curved path corresponding to the setting.

[0041] The first, second and / or third switches or buttons can be designed as separate switches or buttons. According to a preferred embodiment, however, it is proposed that the first switch or button and the second switch or button and / or the first switch or button and the third switch or button and / or the second switch or button and the third switch or button are formed by the same switch or button. This common switch or button can be designed as a sliding switch that can be moved between at least three discrete positions. In a first position, the spacer element is retracted and the model vehicle does not do donuts, but rather drives straight ahead or on a curved path according to a steering angle of the free-running wheels. In a second position, the spacer element is extended and the model vehicle drives donuts in a first direction.In a third position of the switch, the type of curve can be changed or adjusted. The corresponding steering angle of the steerable wheels can be statically preset or change dynamically as the model vehicle moves. If the model vehicle has two spacers on opposite sides of the chassis, the slide switch can extend the other spacer in the third position instead of changing or adjusting the type of curve, and the model vehicle will perform donuts in a second direction opposite to the first direction.

[0042] If the model vehicle has two spacer elements on opposite sides of the chassis, the slide switch can have a fourth discrete switching position in which the model vehicle drives donuts in a second direction opposite to the first direction.

[0043] Further features and advantages of the present invention are explained in more detail below with reference to the figures. Each of the features shown may be essential to the invention on its own, even if this is not explicitly mentioned in the description. Likewise, the individual features described below and shown in the figures may be implemented in any combination with one another, even if this is not explicitly mentioned in the description and / or not explicitly shown in the figures. They show: Fig. 1 a model vehicle according to the invention according to a preferred embodiment in a perspective external view; Fig. 2 the model vehicle from Fig. 1 with the body removed in a top view; Fig. 3 the model vehicle from Fig. 1 with the body removed in a plan view from below; Fig. 4 the model vehicle from Fig. 1 with the body removed in a perspective view from above; and Fig. 5 a section of the model vehicle from Fig. 2.

[0044] Fig. Figure 1 shows a model vehicle according to the invention according to a preferred embodiment, which is designated in its entirety by the reference numeral 2. In the example shown, the model vehicle 2 is realized as a model car with four wheels on two axles, with one wheel arranged at each end of the axles. Alternatively, the model vehicle 2 can also have the shape and design of a tricycle (e.g., a Piaggio Ape Car), a car with more than two axles, or any other two- or multi-axle motor vehicle (e.g., a truck, bus, tractor, construction vehicle, lunar rover, etc.).

[0045] The model vehicle 2 comprises a chassis 4, which in the example shown is designed in several parts, in particular in two parts with the chassis parts 4a and 4b fastened to one another. While a drive arrangement is provided on the rear chassis part 4a, a steering arrangement is provided on the front chassis part 4b. The two-part design of the chassis 4 has the advantage that the existing chassis parts 4a, 4b can simply be replaced by other chassis parts with different drive and / or steering arrangements in order to obtain a different model vehicle with different drive and / or steering characteristics, without the rest of the model vehicle having to be redesigned. For example,It would be conceivable to replace the rear chassis part 4a with another one which - in deviation from the example shown - has a drive block 14 with a spring energy accumulator 90 that can be wound using a key and / or uses the entire energy stored in the spring energy accumulator 90 to propel the vehicle 2 and not also for steering steerable wheels of the vehicle 2. Furthermore, it would be conceivable, for example, to replace the front chassis part 4b with another one which - in deviation from the example shown - has fixedly aligned front wheels and not dynamically steerable wheels during propulsion of the vehicle 2.

[0046] A vehicle body 22 can be detachably attached to the chassis 4. The body 22 is preferably made of plastic and can be formed in one or more parts. Several parts of the body are preferably firmly attached to one another. The several parts of the body 22 can, for example, comprise a first part 22a with the body panels. The first part 22a is preferably made of a colored or painted plastic. Alternatively, the first part 22a can also be made of a preferably colored or painted metal, e.g., aluminum or steel, or a metal alloy. Furthermore, the several parts of the body 22 can, for example, comprise one or more second parts 22b with the window surfaces. The second part(s) 22b are preferably made of a transparent plastic or glass. Furthermore, the several parts of the body 22 can, for example, comprise one or more third parts 22c with the headlights and / or vehicle lights.It would also be conceivable for the multiple parts of the body 22 to comprise, for example, one or more fourth parts 22d with bumpers and / or a front and / or rear spoiler and / or exterior mirrors. The detachable attachment of the body 22 to the chassis 4 can be achieved, for example, by means of a locking or snap-in connection and / or at least one screw, or in any other manner.

[0047] Decorative parts may also be arranged inside the body 22, which in particular obscure the view into the interior of the vehicle 2 of technical components for the drive and / or steering of the vehicle 2. The decorative parts include, for example, a dashboard, interior trim, seats, a steering wheel, an engine cover, or the like. These are preferably made of a colored or painted plastic.

[0048] Furthermore, the model vehicle 2 comprises a spring energy storage device 90 with a spring 92, which is attached to the chassis 4, in particular to the rear chassis part 4a, and in which energy for propelling the model vehicle 2 can be stored by winding the spring 92. The spring energy storage device 90 can be part of a drive block 14 of the model vehicle 2 and can be arranged in particular inside a housing of the drive block 14. Furthermore, the model vehicle 2 comprises at least two driven wheels 8, which are attached to a common first rotational axis 6 and arranged laterally on the model vehicle 2, wherein the first rotational axis 6 is rotatably mounted directly or indirectly on the chassis 4, in particular on the rear chassis part 4a. Furthermore, the model vehicle 2 comprises at least one further wheel 12, two in the example shown, which can rotate about a second rotational axis 10.The second rotation axis 10 extends at a distance from the first rotation axis 6 and is rotatably mounted on the chassis 4, in particular on the front chassis part 4b. The rotatable wheels 12 can rotate relative to the second rotation axis 10, or they are non-rotatably attached to the second rotation axis 10 and rotate together with the rotation axis.

[0049] The wheels 12 rotatable about the second axis of rotation 10 are non-driven or freely rotating or free-running wheels. The second axis of rotation 10 runs parallel to the first axis of rotation 6 when the model vehicle 2 is traveling straight ahead. In the example shown, each non-driven wheel 12 has its own second axis of rotation 10. The second axes of rotation 10 extend in a plane that runs essentially parallel to a surface extension of the chassis 4. In the example, the second axes of rotation 10 are furthermore each steerable in this plane about a steering axis 16. The steering axis 16 are mounted on the chassis 4, in particular on the front chassis part 4b, and preferably extend perpendicular to the surface extension of the chassis 4 or slightly obliquely thereto. Alternatively, only one steerable second axis of rotation 10 could be provided, to which the freely rotatable wheels 12 are attached or relative to which the wheels 12 are freely rotatable.wherein this one steerable second axis of rotation 10 would then be rotatable about a single steering axis, preferably mounted centrally on the chassis 4.

[0050] The rotation axes 6, 10 can be rotatably mounted directly or indirectly on the chassis 4. For example, it is conceivable that if - as shown - the spring energy storage device 90 is part of the drive block 14 of the model vehicle 2, which is fastened to the chassis 4 and from which laterally protrude ends of the first rotation axis 6, to which the driven wheels 8 are rigidly or non-rotatably attached, the first rotation axis 6 is mounted indirectly on the chassis 4 via the drive block 14 or its housing. The one or more second rotation axes 10 can be rotatably mounted indirectly on the chassis 4, for example, via a steering linkage 18.

[0051] Part of the steering linkage 18 are bearing bushes 20, which are mounted on the chassis 4 so as to be rotatable about the steering axes 16 and in which one of the second axes of rotation 10 is rotatably mounted. The steering linkage 18 can steer the wheels 12 guided on the second axes of rotation 10, so that the model vehicle 2 can corner while simultaneously propelling itself along the ground. In the example shown, the steering angles of the rotatable wheels 12 or the corners can be changed dynamically during the propulsion of the model vehicle 2. Alternatively, it would also be conceivable for the steering angles of the rotatable wheels 12 or the corners to be statically preset during the propulsion of the model vehicle 2 before the propulsion of the model vehicle 2. In this case, the second axes of rotation 10 would be mounted indirectly on the chassis 4 via the bearing bushes 20.

[0052] It would also be conceivable for one or more of the rotation axes 6, 10 to be rotatably mounted indirectly on the chassis 4 via a spring linkage (not shown). The spring linkage allows the rotation axis 6; 10 mounted thereon, or a part of the rotation axis 6; 10 mounted thereon, to be spring-loaded and movable in the vertical direction in order to provide suspension for the wheels 8, 12 mounted or attached thereto.

[0053] In the example shown, the spring 92 of the spring energy storage device 90 can be wound up by pulling back the model vehicle 2. During the retraction of the model vehicle 2, the driven wheels 8 of the model vehicle 2 are in contact with a surface on which the model vehicle 2 can travel, so that they execute a rotational movement together with the first rotational axis 6, to which they are rotationally fixed. The rotational movement of the first rotational axis 6 during retraction is directed opposite to the direction of rotation it executes when the model vehicle 2 is propelled forward and consequently leads to a winding or tensioning of the spring 92 of the spring energy storage device 90. As soon as the driven wheels 8 are released with the spring 92 wound up, the wheels 8 rotate, driven by the energy stored in the spring 92. When the model vehicle 2 is placed on the surface with its driven wheels 8, the vehicle 2 moves forward.

[0054] Finally, the model vehicle 2 comprises means (not shown) for converting at least a portion of the energy stored in the spring energy storage device 90 into a rotational movement of the first rotational axis 6 and the driven wheels 8 attached thereto, in order to propel the model vehicle 2 along the ground when at least one of the driven wheels 8 is in contact with the ground and there is sufficient static friction between the at least one driven wheel 8 and the ground. The rotational axis 6 could also be referred to as a drive shaft. The means for converting are preferably also part of the drive block 14 and are arranged in particular inside the housing of the drive block 14. In a particularly simple case, the means merely comprise fastening means with which an inner end of a spring 92, designed as a spiral spring, of the spring energy storage device 90 is fastened in a rotationally fixed manner to the first rotational axis 6.An outer end of the coil spring 92 is then preferably attached directly or indirectly to the chassis 4, in particular to the housing of the drive block 14. In a more complex embodiment, these means for converting the energy stored in the spring energy storage device 90 into a rotational movement of the first rotational axis 6 can also comprise a linkage and / or any desired gearing.

[0055] It is proposed that the model vehicle 2 comprise means 26 configured to selectively reduce static friction between a driven wheel 8a arranged on a first side 2a of the model vehicle 2 and the ground, while static friction between another driven wheel 8b arranged on the other side 2b of the model vehicle 2 and the ground remains largely unchanged. This enables the model vehicle 2 according to the invention to travel, in the simplest possible manner, not only on any desired first path but also on a very tight circular path (so-called donuts), in particular without changing the treads of the wheels 8, 12 or the wheels 8, 12 themselves. The diameter of the desired donut is significantly smaller than the turning circle of the model vehicle 2 with the steerable wheels 12 normally turned during normal cornering.In particular, the diameter of the donut is less than half the turning circle of the model vehicle 2 during normal cornering. During a donut turn, the wheels 12 rotatable about the second axis of rotation 10 preferably have a movement component transverse or oblique to a rolling direction of the wheels 12 about the second axis of rotation 10.

[0056] If the static friction between the driven wheels 8 arranged on both sides 2a, 2b of the model vehicle 2 or their running surfaces and the ground is the same and sufficiently large for propulsion, the model vehicle 2 travels on a straight line or any curved path, depending on how the second axis of rotation 10 is aligned in the plane of the surface extension of the chassis 4, ie depending on the direction in which the wheels 12, which are freely rotatable about the second axis of rotation 10, are directed.

[0057] The invention takes advantage of the fact that when the model vehicle 2 is driven via the driven wheels 8 on both sides 2a, 2b of the model vehicle 2, i.e., with a largely uniform propulsion via the driven wheels 8 on both sides 2a, 2b of the model vehicle 2, the model vehicle 2 travels on any desired first path. The type or course of the first path depends on a steering angle with which the additional wheels 12, which are freely rotatable about the second axis of rotation 10, are turned in the plane of the surface extension of the chassis 4. With a steering angle of 0°, i.e., additional wheels 12 are not turned, or in the absence of a steering function, the first path is designed as a straight line, so that the model vehicle 2 travels straight ahead. With a steering angle of #0°, the first path is designed as a more or less large curve in any desired direction, i.e.,The model vehicle 2 travels along any curved path. The steering angle can be dynamically varied in direction and magnitude during propulsion using the steering linkage 18, as in the example shown (explained in more detail below), so that the first path can be an ellipse, a figure-8 curve, an S-curve, or any other variable curved path. However, the steering angle can also be fixed in direction and magnitude before propulsion of the model vehicle 2, for example, set manually, and remain constant during propulsion. In this case, the first path would be a circular path.

[0058] With reduced static friction between the driven wheel 8a and the ground on the first side 2a of the model vehicle 2, propulsion of the model vehicle 2 is realized primarily on one side via the driven wheel 8b arranged on the opposite second side 2b of the model vehicle 2, so that the model vehicle 2 drives a tight curve or a donut in the direction of the first side 2a of the model vehicle 2. In this sense, it is proposed that the static friction between the running surface of the driven wheel 8b arranged on the second side 2b and the ground is sufficiently large to ensure sufficient propulsion of the model vehicle 2 on the ground - even with reduced static friction on the first side 2a.

[0059] The model vehicle 2 can therefore be switched between driving on a first path (straight ahead or on any curved path), the course of which is determined by a steering angle of the wheels 12 freely rotatable about the second axis of rotation 10, and driving on particularly tight curves, so-called donuts, wherein the freely rotatable wheels 12 during a donut drive preferably have a movement component transversely or obliquely to their rolling direction about the second axis of rotation 10.

[0060] The driven wheels 8 arranged laterally on the model vehicle 2 can protrude laterally beyond the chassis 4 or the model vehicle 2 or its body 22, or can be arranged in wheel housings 24 which are formed laterally in the chassis 4 or in the body 22, so that the wheels 8 do not protrude laterally beyond the chassis 4 or the model vehicle 2 or its body 22.

[0061] The static friction between the running surface of the non-driven or free-running wheels 12 of the model vehicle 2 and the ground is preferably smaller than the static friction between the driven wheel 8b arranged on the second side 2b, preferably so small that sliding friction occurs, so that the free-running wheels 12 can roll or slide over the ground not only in the direction of travel of the model vehicle 2, but also with a transverse component to the direction of travel. This facilitates or enables the model vehicle 2 to drive on particularly tight curves (so-called donuts), which have a smaller diameter than the turning circle of the model vehicle 2 with the wheels 12 turned.

[0062] Reducing the static friction between the driven wheel 8a arranged on the first side 2a and the ground can be achieved in various ways. In the example shown, the driven wheel 8a arranged on the first side 2a of the model vehicle 2 is raised, preferably completely off the ground. This means that the driven wheel 8a arranged on the first side 2a is pressed onto the ground with less force, if at all, thereby reducing the static friction.

[0063] In the example shown, the means 26 for reducing static friction comprise a spring 28 arranged laterally on an underside 28 of the chassis 4 between a retracted position (not shown) and an extended position (cf. Fig. 1 and Fig. 3) Movable spacer element 30, wherein the spacer element 30 is arranged closer to the driven wheel 8a arranged on the first side 2a of the model vehicle 2 and further away from the other driven wheel 8b arranged on the other side 2b of the model vehicle 2. In its retracted position, the spacer element 30 allows contact of the driven wheels 8 with the ground on both sides 2a, 2b of the model vehicle 2 and sufficient static friction between the driven wheels 8 and the ground.In its extended position, the spacer element 30 comes into contact with the ground and lifts the chassis 4 laterally, so that there is less static friction between the driven wheel 8a arranged on the first side 2a of the model vehicle 2 and the ground, while the static friction remains largely unchanged between the driven wheel 8b arranged on the other side 2b of the model vehicle 2 and the ground.

[0064] According to this embodiment, the fact is exploited that when the model vehicle 2 is driven via the driven wheels 8 arranged on both sides 2a, 2b, with the spacer element 30 retracted, the model vehicle 2 travels on the first path (straight ahead or on any curved path). With an extended spacer element 30 arranged near or on the first side 2a of the model vehicle 2, the model vehicle 2 is driven primarily via the second wheel 8b arranged laterally on the opposite second side 2b of the model vehicle 2, so that the model vehicle 2 travels a tight curve or a so-called donut in the direction of the first side 2a of the model vehicle 2.In this sense, it is proposed that the static friction between the running surface of the second driven wheel 8b and the ground is sufficiently large to ensure sufficient propulsion on the ground, even when the spacer element 30 is extended.

[0065] The first driven wheel 8a, raised by the extended spacer element 30, has lower static friction with the ground than the second wheel 8b, which is in normal contact with the ground, or may even be completely lifted off the ground. The lower static friction results at least in part from the lifting or lifting of the first wheel 8a from the ground. This reduces the contact force with which the first wheel 8a presses against the ground, preferably even to zero. If there is still slight contact between the first wheel 8a and the ground when the spacer element 30 is extended, the lower static friction can be supported by a different material or a different design of the tread of the first wheel 8a compared to the tread of the second wheel 8b.

[0066] As an alternative to laterally lifting the chassis 4, the driven wheel 8a arranged on the first side 2a can also be lifted by laterally lifting the first rotation axis 6 on the first side 2a of the model vehicle 2.

[0067] In another embodiment (not shown), it would be conceivable for the model vehicle 2 to have a movable spacer element 30 on each of the two opposite sides 2a, 2b on the side of the underside 28 of the chassis 4. The first spacer element 30 would be arranged closer to a first of the driven wheels 8a and further away from the second driven wheel 8b, and the other spacer element 30 would be arranged closer to the second driven wheel 8b and further away from the first driven wheel 8a. In their retracted positions, the two spacer elements 30 on both sides 2a, 2b of the model vehicle 2 enable contact of the driven wheels 8 with the ground and uniform propulsion of the vehicle 2 on both sides.

[0068] When (with the second spacer element 30 retracted) the first spacer element 30 comes into contact with the ground in its extended position, the chassis 4 is lifted laterally on the first side on which the first driven wheel 8a is arranged, so that there is less static friction between the first driven wheel 8a and the ground, while the static friction between the second driven wheel 8b and the ground remains largely unchanged, so that the model vehicle 2 drives a tight curve (so-called donut) in the direction of the first side 2a of the model vehicle 2.In contrast, when the second spacer element 30 comes into contact with the ground in its extended position (with the first spacer element 30 retracted), the chassis 4 is lifted laterally on the second side 2b, on which the second driven wheel 8b is arranged, so that there is less static friction between the second driven wheel 8b and the ground, while the static friction between the first driven wheel 8a and the ground remains largely unchanged, so that the model vehicle 2 travels a tight curve (so-called donut) toward the second side 2b of the model vehicle 2. In this way, the model vehicle 2 can selectively travel donuts in two opposite directions.

[0069] In the example shown, the spacer element 30 can be controlled by means of a first switch 32 (cf. Fig. 3), which is designed, for example, as a rotary-slide switch, can be selectively switched between the retracted position and the extended position and fixed in this position. The switch 32 is accessible from the outside and is arranged on the model vehicle 2 so that it can be operated manually by a user of the model vehicle 2, preferably without tools, e.g., with a finger of the user. In the example shown, the switch 32 is arranged on the underside 28 of the chassis 4 so that the external appearance of the model vehicle 2 standing or moving on the ground is not impaired. However, it would also be conceivable for the switch 32 to be arranged on the front, rear, or top of the vehicle 2. The use of a button instead of the switch 32 would also be conceivable.

[0070] The switch 32 can be rotated or displaced by a few angular degrees in a plane parallel to the surface extension of the chassis 4 about a rotation axis 34 running perpendicular to the surface extension (cf. Fig. 2, Fig. 4 and Fig. 5). The switch 32 is attached to the underside of a disk or a corresponding disk section 36 or is formed integrally therewith. The disk section 36 is arranged on the top side of the chassis 4 or inside the vehicle 2. The disk section 36 is mounted on the chassis 4 so as to be rotatable about the rotation axis 34. It has an actuating element 38 which, by rotating the disk section 36, can switch the spacer element 30 between the extended and retracted positions. In the example shown, the actuating element 38 is formed on an outer peripheral surface 38 of the disk section 36. Likewise, the actuating element 38 could also be formed on the underside of the disk section 36.

[0071] The spacer element 30 is articulated to the chassis 4 via a lever 40. The lever 40 is movable about a rotation axis 42, which extends in a plane parallel to the surface extension of the chassis 4. A bearing part 44 is attached to the top of the chassis 4 or is formed integrally therewith. The rotation axis 42 extends through the bearing part 44. Opposite the bearing part 44, the lever 40 has an actuating pin 46, which is designed and arranged to engage with the actuating element 38 of the disc section 36. The actuating element 38 has an inclined sliding surface 48 facing the actuating pin 46, along which the actuating pin 46 can slide during the transition between the retracted position of the spacer element 30 and the extended position. Fig. 5, the actuating element 38 and the actuating pin 46 are shown in the retracted position of the spacer element 30. The spacer element 30 is arranged on the underside of the lever 40. The spacer element 30 and the actuating pin 46 are preferably arranged in the region of a distal end of the lever 40. It is conceivable that the lever 40 is held spring-loaded in a position that corresponds to the retracted position of the spacer element 30.

[0072] In the example shown, switch 32 is—as mentioned—constructed as a slide switch that can be moved between two discrete positions. In a first position (see Fig. 2 and Fig. 5) the spacer element 30 is retracted and the model vehicle 2 does not do donuts, but rather straight ahead or in a curve according to a steering angle of the free-running wheels 12, wherein the diameter of a circular path of the curve in this case depends on a steering angle of the free-running wheels 12. In a second position (not shown), the spacer element 30 is extended, and the model vehicle 2 does donuts, wherein the diameter of the donuts is smaller than a minimum turning circle of the model vehicle 2 during normal cornering. The minimum turning circle is reached at the maximum steering angle of the free-running wheels 12. This particularly small diameter of the donuts is achieved, for example, by the one-sided drive of the model vehicle 2 leading to a transverse movement component of the free-running wheels 12 on the ground only via one of the two laterally arranged driven wheels 8 (in the example via the second wheel 8b).The transverse movement component is preferably directed obliquely or transversely to a rolling direction of the free-running wheels 12 about the second axis(es) of rotation 10.

[0073] If the model vehicle 2 has two spacer elements 30 arranged on opposite sides 2a, 2b, a separate switch or button can be provided for each spacer element 30, which selectively extends or retracts the corresponding spacer element 30 and fixes it in this position. In this case, however, a common switch or button would preferably be provided, which alternately extends or retracts both spacer elements 30 and holds them in these positions. The switch or button would preferably be designed as a slide switch that is adjustable between at least three discrete positions. In a first position, both spacer elements 30 would be retracted and the model vehicle 2 would not drive in donuts, but rather, according to a steering angle of the free-running wheels 12, straight ahead or in a curve, wherein the diameter of the circular path of the curve would depend on a steering angle of the free-running wheels 12.In a second position, a first spacer element 30 is extended while the other spacer element 30 is retracted, and the model vehicle 2 drives donuts in a first direction, wherein the diameter of the donuts is smaller than a minimum turning circle of the model vehicle 2. In a third position, the second spacer element 30 is extended while the other spacer element 30 is retracted, and the model vehicle 2 drives donuts in a second direction opposite to the first direction, wherein here too the diameter of the donuts is smaller than a minimum turning circle of the model vehicle 2.

[0074] Because the wheels 12, which are freely rotatable about the second axes of rotation 10 and are steerable about the steering axis 16, the model vehicle 2 can also travel on a curved path. The steering axes 16 can run obliquely, transversely, or skewed to the second axes of rotation 10. Driving on a curved path is characterized in that a curve radius is largely determined by a steering angle of the steerable wheels 12 about the steering axes 16. If the static friction between the tread of the steerable wheels 12 and the ground is optimal (i.e. there is no sliding friction), the curve radius is predetermined by the steering angle of the steerable wheels 12. In the example shown, the steering direction and / or the steering angle of the steerable wheels 12 changes dynamically as the model vehicle travels forward. The dynamic change in the steering direction orThe steering angle can be time-dependent, dependent on the distance traveled by the model vehicle 2 during forward travel, or can also be random.

[0075] The model vehicle 2 has means for converting at least a portion of the energy stored in the spring energy storage device 90 into at least one type of dynamically changing steering movement of the wheels 12, which are freely rotatable about the second axes of rotation 10, during the propulsion of the model vehicle 2. In addition to the steering linkage 18, the means comprise a transmission 50 for transmitting a portion of the energy stored in the spring energy storage device 90 or a corresponding rotational movement to the steering linkage 18.

[0076] As in Fig. As can be seen in Figure 2, the gear 50 comprises a worm 52 which is attached to the rotational axis 6 driven by the spring energy storage device 90 or is formed integrally therewith and which meshes with a worm wheel 54 of the gear 50. The worm 52 and the worm wheel 54 form a worm gear. A smaller first gear 56 is attached to the worm wheel 54 or is formed integrally therewith, which in turn meshes with a larger second gear 58. A second gear 58 (cf. Fig. 4) A downward-facing gear ring 60 is attached to or formed integrally with the gear ring 58, which meshes with another gear 62. The gear ring 58 and the further gear 62 form an angular gear. The worm gear 54 with the first gear 56 and the second gear 58 with the gear ring 60 are each mounted on the chassis 4 so as to be rotatable about a rotational axis, with the rotational axes running parallel to each other and perpendicular to the driven rotational axis 6. The angular gear could also be designed as a bevel gear, in which case the gear ring 58 and the further gear 62 would be designed as bevel gears with helical teeth.

[0077] The transmission 50 further comprises a transmission shaft 64, which is fastened to the further gear 62 or is formed integrally therewith. At the end of the shaft 64 opposite the further gear 62, an output gear 66 is fastened or formed integrally with the shaft 64, which engages with a downward-facing ring gear of a drive gear 68. The output gear 66 and the drive gear 68 also form an angular gear. This could also be designed as a bevel gear, in which case the output gear 66 and the ring gear of the drive gear 68 would be designed as bevel gears with helical teeth. The drive gear 68 is mounted on the chassis 4 for rotation about an axis of rotation, which runs parallel to the axes of rotation of the worm gear 54 with the first gear 56 and the second gear 58 with the ring gear 60.The transmission shaft 64 with the further gear 62 and the output gear 66 is mounted on the chassis 4 so as to be rotatable about an axis of rotation that runs parallel to a surface extension of the chassis 4. Corresponding bearing blocks, which are attached to the chassis 4 or formed integrally therewith, are shown in . Fig. 2 is designated by reference numeral 70. The worm gear 54 with the first gear 56 and the second gear 58 with the gear ring 60 form a reduction gear, which converts a relatively fast rotation of the rotational axis 6 into a slower rotation of the shaft 64.

[0078] The steering linkage 18 translates a rotational movement of the driving wheel 68 into a corresponding steering movement of the freely rotatable wheels 12 about the steering axes 16.

[0079] For this purpose, the steering linkage 18 in the example shown comprises a driver element 74 which is rotatably mounted on the chassis 4 about a rotation axis 72 and which is, for example, T-shaped. A gap 76 is formed in the stem or shaft of the "T", in which gap a driver pin 78 formed on the driver wheel 68 is longitudinally guided. Rotation of the driver wheel 68 about its rotation axis thus leads to an oscillating rotational movement of the driver element 74 about its rotation axis 72. Driver recesses 80, for example holes, are formed at the distal ends of the crossbar of the "T", each of which is designed to rotatably receive an engagement pin 82. The engagement pins 82 are each fastened to a connecting lever 84 or are formed integrally therewith. The connecting levers 84 are each rigidly fastened to one of the bearing bushes 20 and are formed integrally therewith.The oscillating back and forth movement of the driver element 74 thus leads to an oscillating steering movement of the wheels 12 about the steering axes 16. Depending on the duration of the steering angle of the wheels 12, the model vehicle 2 thereby executes a curve on an S-shaped or figure-8-shaped path.

[0080] A spring element 86 can be assigned to the steering linkage 18, which keeps the steerable wheels 12 in their straight-ahead direction. Steering of the wheels 12 would then occur counter to the force of the spring element 86.

[0081] Of course, the means for converting energy stored in the spring energy storage device 90 into a dynamically changing steering movement could also be designed differently than described in the example. In particular, the transmission 50 and / or the steering linkage 18 could be designed differently. For example, it would be conceivable for the driver element 74, instead of being rotatable about the rotational axis 72, to be guided on the chassis 4 so that it can be longitudinally displaced in a direction transverse to a longitudinal extent of the model vehicle 2, so that the driver element 74 would execute an oscillating translational movement instead of the oscillating rotational movement. In this way, the model vehicle 2 could also travel on other types of curved paths than the model vehicle 2 described here.

[0082] Unlike the example shown, the means for converting energy stored in the spring energy storage device 90 into a steering movement, and thus the dynamic steering movement of the freely rotatable wheels 12 or variable cornering of the model vehicle 2 during propulsion, can be selectively activated and / or deactivated by means of a second switch or button. Using the second switch or button, the forward travel of the model vehicle 2 could thus be switched between dynamic cornering and—depending on the position of the first switch or button—travel on the first path (straight ahead or a preset cornering) or a donut-like travel. The second switch could also be configured to set the type of cornering. In this sense, switching could be made between a statically preset steering angle and a dynamically variable steering angle.

[0083] Furthermore, it would be conceivable to use the second or another switch or button to selectively switch between different types of dynamically variable steering angles. To implement different types of dynamically variable steering angles, several different transmissions 50 and steering linkages 18 can be provided, between which switching can be performed, or one type of transmission 50 and / or steering linkage 18 can be designed to be switchable.

[0084] The first switch 32, the second and / or the other switch or button can be configured as separate switches or buttons. However, the first switch 32 and the second switch or button and / or the first switch 32 and the other switch or button and / or the second switch or button and the third switch or button are preferably formed by the same switch or button. This common switch or button can be configured as a slide switch that can be switched between at least three discrete positions.

[0085] In the example described, the spacer element 30 can have a sliding element 88 at a distal end in its extended position. This is made of a material and / or shaped such that the distal end of the spacer element 30 slides over the ground with as little static friction as possible. An underside of the sliding element 88 facing the ground can be made of a hard material, such as a hard plastic or metal. The underside of the sliding element 88 is preferably smooth. The sliding element 88 can be rounded or skid-shaped. In the example shown, the sliding element 88 has the shape of a spherical segment.

[0086] Alternatively, the spacer element 30 has, at a distal end in its extended position, a roller element (not shown) mounted rotatably about a rolling axis, which is designed to roll on the ground when the spacer element 30 comes into contact with the ground. The rolling element can facilitate the sliding of the distal end of the spacer element 30 over the ground by rolling over the ground in a direction transverse to the rolling axis.

[0087] It would also be conceivable for the spacer element 30 to have a rotatably mounted ball element (not shown) at a distal end in its extended position, which is designed to roll on the ground when the spacer element 30 comes into contact with the ground. The ball element can facilitate the sliding of the distal end of the spacer element 30 over the ground by rolling over the ground in all directions. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2022 297 019 A1

[0002]

Claims

[1] Model vehicle (2), comprising - a chassis (4), - a spring energy storage device (90) attached to the chassis (4) comprising a spring (92), in which energy for propulsion of the model vehicle (2) can be stored by winding up the spring (92), - at least two driven wheels (8; 8a, 8b) rigidly mounted on a common first axis of rotation (6) and arranged laterally on two opposite sides (2a, 2b) of the model vehicle (2), wherein the first axis of rotation (6) is rotatably mounted on the chassis (4), - means for converting at least part of the energy stored in the spring energy storage device (90) into a rotational movement of the first rotational axis (6) and the driven wheels (8; 8a, 8b) in order to propel the model vehicle (2) on a surface when at least one of the driven wheels (8; 8a, 8b) is in contact with the surface and there is sufficient static friction between the at least one driven wheel (8; 8a, 8b) and the surface, and - at least one further wheel (12) rotatable about a second axis of rotation (10), wherein the second axis of rotation (10) is rotatably mounted on the chassis (4) at a distance from the first axis of rotation (6), characterized byin that the model vehicle (2) has means (26) which are designed to selectively reduce a static friction between a driven wheel (8a) arranged on a first side (2a) of the model vehicle (2) and the ground, while a static friction between another driven wheel (8b) arranged on the other side (2b) of the model vehicle (2) and the ground remains largely unchanged. [2] Model vehicle (2) according to claim 1, wherein the means (26) for reducing the static friction are designed to lift the driven wheel (8a) arranged on the first side (2a) of the model vehicle (2), preferably to lift it off the ground. [3] Model vehicle (2) according to claim 1 or 2, wherein the means (26) for reducing the static friction comprise a spacer element (30) which is selectively movable laterally on an underside (28) of the chassis (4) between a retracted position and an extended position, wherein the spacer element (30) is arranged closer to the driven wheel (8a) arranged on the first side (2a) of the model vehicle (2) and further away from the other driven wheel (8b) arranged on the other side (2b) of the model vehicle (2) and in its retracted position on both sides (2a, 2b) of the model vehicle (2) ensures contact of the driven wheels (8; 8a, 8b) with the ground and sufficient static friction between the driven wheels (8;8a, 8b) and the ground and which, in its extended position, comes into contact with the ground and lifts the chassis (4) laterally, so that there is reduced static friction between the driven wheel (8a) arranged on the first side (2a) of the model vehicle (2) and the ground (28), while the static friction remains largely unchanged between the driven wheel (8b) arranged on the other side (2b) of the model vehicle (2) and the ground. [4] Model vehicle (2) according to claim 3, wherein the spacer element (30) is selectively movable between the retracted position and the extended position by means of a first switch (32) or button and can be fixed in this position. [5] Model vehicle (2) according to claim 3 or 4, wherein the spacer element (30) has, at a distal end in its extended position, a sliding element (88) which is made of a material and / or is formed in a shape to slide over the ground with the lowest possible static friction when the spacer element (30) comes into contact with the ground. [6] Model vehicle (2) according to claim 3 or 4, wherein the spacer element (30) has, at a distal end in its extended position, a roller element which is mounted rotatably about a rolling axis and is designed to roll on the ground when the spacer element (30) comes into contact with the ground. [7] Model vehicle (2) according to claim 3 or 4, wherein the spacer element (30) has, at a distal end in its extended position, a rotatably mounted ball element which is designed to roll on the ground when the spacer element (30) comes into contact with the ground. [8] Model vehicle (2) according to one of the preceding claims, wherein the spring energy storage device (90) can be wound up by means of a key or by pulling back the model vehicle (2), wherein when the model vehicle (2) is pulled back, the driven wheels (8; 8a, 8b) of the model vehicle (2) are in contact with the ground so that they execute a rotational movement. [9] Model vehicle (2) according to one of the preceding claims, wherein the at least one further wheel (12) rotatable about the second axis of rotation (10) is steerable about a steering axis (16), wherein the steering axis (16) extends obliquely, transversely or skewed to the second axis of rotation (10). [10] Model vehicle (2) according to claim 9, wherein the model vehicle (2) comprises means (18, 50) for converting at least part of the energy stored in the spring energy storage device (90) into at least one type of steering movement that changes dynamically during the propulsion of the model vehicle (2). [11] Model vehicle (2) according to claim 10, wherein the means (18, 50) for converting at least part of the energy stored in the spring energy storage device (90) into a steering movement and thus into the dynamic steering movement of the model vehicle (2) during propulsion can be activated and / or deactivated by means of a second switch or button. [12] Model vehicle (2) according to claim 10 or 11, wherein the model vehicle (2) comprises means for converting at least part of the energy stored in the spring energy storage device (90) into several different types of steering movements that change dynamically during the propulsion of the model vehicle (2), wherein in each case one of the different types of steering movements can be activated by means of a third switch or button and / or at least one of the other types of steering movements can be deactivated by means of the third switch or button. [13] Model vehicle (2) according to claim 4 and at least one of claims 11 and 12, wherein the first switch (32) or button and the second switch or button and / or the first switch or button and the third switch or button are formed by the same switch or button. [14] Model vehicle (2) according to one of claims 9 to 13, wherein the at least one type of steering movement which changes dynamically during the propulsion of the model vehicle (2) comprises at least one steering movement so that the model vehicle (2) travels on at least one of the following curved paths during the propulsion: - a circular orbit, - an elliptical curved path, - an S-curve track, - a curved track in the shape of a figure eight, - a meandering curved track.

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