Improved skateboard-type land vehicle

Abstract

The invention relates to a vehicle comprising a platform (1), a steered front wheel (3) arranged entirely underneath the platform and free to pivot about a transverse axis (A3) relative to a support (4) that is rotatably mounted so as to rotate relative to a bearing (5) on the median longitudinal axis of the platform, and a rear wheel (6) that is rotatably mounted so as to rotate relative to the platform about a fixed transverse axis (A6) of this platform, a portion of the rear wheel being located above the upper face of the platform, and this rear wheel being aligned with the bearing of the front wheel. In addition, the diameter (d) of the front wheel is between 40 mm and 150 mm, the diameter (D) of the rear wheel is between 100 mm and 400 mm, and the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel is between 1.25 and 7. The skateboard according to the invention exhibits both satisfactory stability and high manoeuvrability during use on many types of surfaces. It allows the user to perform a variety of tricks, has a simple and reliable design while also being inexpensive to manufacture and maintain, and has a modular structure that allows it to adopt different configurations depending in particular on the user's level.

Description

[0001] LAND VEHICLE, OF THE WHEELBOARD TYPE

[0002] Technical field of the invention

[0003] The invention relates to the technical field of skateboards, or wheeled skateboards. These land vehicles are designed to transport a user, whether in urban or natural environments, for sporting or recreational activities. Such skateboards allow users to reproduce the gliding sensations they might experience while practicing on water or snow.

[0004] State of the art

[0005] The state of the art includes numerous wheeled skateboards or wheeled devices, among which we should first mention those featuring a platform, either flexible or rigid, combined with two small front and rear steering wheels. However, this solution generates instability on most surfaces and, moreover, discomfort on rough surfaces. Furthermore, the rear steering wheel, that is, the wheel that rotates relative to the platform around a vertical or oblique axis, does not allow for the desired dynamism in practice.

[0006] In particular, the skateboards described in WO 2009 / 156983, WO 2015 / 119304, and WO 2023 / 056340 allow for turning thanks to their two movable wheels, and also for performing U-turns on the spot. The forward movement of these boards is achieved through rotations of the user's pelvis. However, the desired dynamism is not achieved because the rear steering wheel does not maintain its course when lateral support is engaged during the aforementioned pelvic movements. This tends to accentuate turns, which consequently limits speed.

[0007] The prior art documents WO 2007 / 127554 (a flexible monocoque platform with two directional wheels) and WO 2022 / 072367 (convertible to two or three wheels) are of the same general type as those mentioned at the beginning of this section. As such, they share the same drawbacks as the boards conforming to the three documents in the preceding section. However, WO 2007 / 127554 and WO 2022 / 072367 teach the construction of a flexible platform, specifically by creating a central torsional axis for the board. This arrangement is intended to facilitate maintaining or even increasing speed through pelvic rotations by the user. However, this increases the board's instability and lack of dynamism, while also making it more mechanically complex. Furthermore, the small size of the two or three wheels quickly limits its performance on uneven surfaces.The five boards shown above do not allow for easy launch into a bowl or ramp by pushing off the back of the board to perform a trick called a "drop." This is because the user's rear foot is then positioned above the moving rear wheel.

[0008] The skateboards described in WO 2010 / 055372 and WO 2019 / 231 433 (skateboards with a single front steering wheel and two rear wheels mounted on a classic skateboard truck allowing for slight travel) present the same drawback on uneven surfaces due to their small-diameter wheels. Furthermore, the rear truck does not allow for significant lean angles because the wheels interfere with the underside of the board.

[0009] We should also mention US 7,172,205 and FR 2,881,059, which describe boards combining the main features and, consequently, the drawbacks of the first three boards mentioned above. These alternative solutions include additional wheels positioned laterally. This design limits the board's lean angle during use, thus reducing its overall maneuverability.

[0010] US 2013 / 049317, which discloses a board intended to simulate the feel of a longboard. To this end, the document instructs users to use a two-wheeled skateboard truck at the rear. The resulting board has a complex structure but is not very maneuverable. This limits its use to large spaces and prevents its use on features such as bowls, ramps, skateparks, or pumptracks.

[0011] In view of the above, the invention addresses various disadvantages of the prior art mentioned above.

[0012] The invention aims in particular to provide a wheeled board which offers both satisfactory stability and great maneuverability in use, on many types of surfaces.

[0013] It also aims to offer such a board, which allows its user to perform a variety of tricks, including drops, curves, carving, wheelies, and even U-turns on the spot. It also aims to offer such a board with a simple and reliable design, while being inexpensive to produce and maintain.

[0014] Its ultimate aim is to offer such a board which has a modular structure, allowing it to adopt different configurations depending in particular on the level of the user.

[0015] Objects of the invention

[0016] According to the invention, at least one of the above objectives is achieved by means of a wheeled board type vehicle (I) comprising a platform (1) defining a median longitudinal axis (A1), corresponding substantially to the direction of movement of the vehicle, said platform comprising an upper face (10), a lower face (11), a front edge (14), a rear edge (16) and lateral sides, a front steering wheel (3) disposed entirely below the lower face of the platform, in operation, this front wheel being free to pivot, about a transverse axis (A3), relative to a support (4), which support is mounted for rotation relative to a bearing (5) about an axis of rotation (A4) located substantially on the median longitudinal axis of the platform, in top view, a rear wheel (6) mounted for rotation relative to the platform about a fixed transverse axis (A6) of this platform,a portion of the rear wheel being situated above the upper face of the platform, this rear wheel extending substantially along the median longitudinal axis of the platform so as to be aligned with the bearing of the front wheel the diameter (d) of the front wheel being between 40mm and 150mm (millimeters), the diameter (D) of the rear wheel being between 100mm and 400mm, and the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel being between 1.25 and 7.

[0017] According to other characteristics, which can be implemented individually or in any technically compatible combinations: the diameter (d) of the front wheel is between 50 and 130 mm, the diameter (D) of the rear wheel is between 140 and 320 mm, the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel is between 1.8 and 5. the diameter (d) of the front wheel is between 60 and 80 mm, the diameter (D) of the rear wheel is between 165 mm and 250 mm, and the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel is between 2.5 and 3.5. the difference in altitudes (DH) between the upper face (10) and the fixed transverse axis (A6) is between +35mm and -55mm, preferably between +30mm and -50mm, even more preferably between +25mm and -45mm, the vehicle further includes means (7) for mounting the rear wheel on the platform (1),which are adapted to selectively provide several height differences (DH1 - DH3) between the upper face (10) of the platform and the fixed transverse axis (A6) of rotation of the rear wheel, the mounting means include at least one bracket and, in particular, two brackets (7) provided on either side of the rear wheel, in top view, each bracket (7) having a base (70) adapted to be selectively fixed to the upper or lower face of the platform, as well as a mounting flange (71) for a physical axis of rotation of the rear wheel, adapted to extend selectively upwards or downwards from the base, the mounting means are adapted to provide three relative configurations between the rear wheel and the platform, namely: a raised configuration of the rear wheel,in which the base is fixed to the upper face and the mounting flange extends upwards; a lowered configuration of the rear wheel, in which the base is fixed to the lower face and the mounting flange extends downwards; an intermediate configuration of the rear wheel, in which the mounting flange extends into the thickness of the platform; the rear wheel extends through a notch (2) formed in the platform, said notch being bordered by opposing front, rear and side walls respectively, reinforcing means being advantageously provided at the level of at least a part of said walls; the notch is hollowed out with a recess (26) allowing the reception of at least a part of the mounting means; in said intermediate configuration, the vehicle further comprises a set of shims (56, 57) of different heights,suitable for interposing between the front wheel pivot point (5) and the underside (11) of the platform, the distance (L12) or wheelbase between, on the one hand, the pivot point of the front wheel on the fixed pivot point and, on the other hand, the axis of rotation of the rear wheel is between 310 mm and 750 mm, preferably between 400 and 600 mm, the angle of inclination (a4), relative to the vertical, of the axis of rotation (A4) of the support (4) of the front wheel (3) relative to the fixed pivot point, is between 10° and 40°, preferably between 16° and 33°, the distance (L15) between the transverse axis and the rear edge is between 100 and 500 mm, preferably between 240 and 330 mm, the distance (L13) between the pivot point of the front wheel on the pivot point fixed and the front edge is between 15 and 250 mm, preferably between 50 and 110 mm, the total length (L1) of the board is between 500 and 1300 mm, preferably between 700 and 1000 mm,The total width (11) of the board is between 160 mm and 360 mm, preferably between 200 mm and 300 mm.

[0018] Description of the figures

[0019] The invention will be described below, with reference to the accompanying drawings, given solely by way of non-limiting examples, in which:

[0020] [Fig. 1] is a perspective view, illustrating a skateboard according to the invention, viewed from above.

[0021] [Fig. 2] is a view from below, illustrating this same skateboard.

[0022] [Fig. 3] is a side view, illustrating this skateboard and its characteristic dimensions.

[0023] [Fig. 4] is a perspective view, illustrating a support for the front wheel of the board in the previous figures.

[0024] [Fig. 5] is a side view, illustrating on a larger scale the articulation of this front wheel on the platform of the board.

[0025] [Fig. 6] is a perspective view, illustrating on a larger scale the mounting of the rear wheel on the platform of the board.

[0026] [Fig. 7] is a perspective view, illustrating from another angle the rear wheel assembly of figure 6.

[0027] [Fig. 8] is a schematic side view, illustrating a first functional configuration of the skateboard according to the invention.

[0028] [Fig. 9] is a schematic side view, analogous to figure 8, illustrating another functional configuration in which the platform height is different.

[0029] [Fig. 10] is a schematic side view, similar to Figures 8 and 9, illustrating yet another functional configuration in which the platform height is different. [Fig. 11] is a view along arrow XI in Figure 9, illustrating the interior of the platform as well as various mechanical components housed within it.

[0030] [Fig. 12] is a schematic view, illustrating different components of the braking system that can be fitted to the skateboard according to the invention.

[0031] Detailed description

[0032] The skateboard according to the invention, which is designated as a whole by the reference I, essentially comprises a platform 1, a single front wheel, a single rear wheel, and means enabling the mounting and articulation of these wheels on this platform.

[0033] Platform 1, generally rectangular when viewed from above, has a median longitudinal axis labeled A1. It comprises an upper surface 10 and a lower surface 11, referring to the board whose wheels rest on the ground. The intermediate region of the platform is denoted 12, the front region of the platform 13, which terminates in a front edge 14, and the rear region of the platform 15, which terminates in a rear edge 16. The respective ends of regions 12, 13, and 15 will be specified below. Finally, the opposite lateral sides of the platform are denoted 17 and 18.

[0034] The platform material can be of any suitable type, particularly suitable for the traditional manufacture of skateboards. Examples include wood, any plastic material obtained by molding or 3D printing, and composite fibers with a thickness between 0.5 mm and 50 mm, preferably between 10 mm and 18 mm. Preferably, layers of wood are used, glued together and then compressed using a press. As shown in Figure 3, the rear section is raised, while the front section has a slight concave shape. During manufacturing, to ensure these shapes are maintained, the wooden deck sheets can be held in place using spacers or a mold.

[0035] As can be seen in Figures 6 and 7, a notch 2 is cut into the platform 1, symmetrical about the median longitudinal axis A1. This notch, which allows the rear wheel to pass through as described below, creates a material shortage. Therefore, it is advantageous to reinforce the platform by using slightly more layers of wood than are typically used in skateboard construction. For example, eight or nine layers of wood can be used to make the platform 1. Furthermore, the peripheral walls of the notch 2, which allow the rear wheel 6 to pass through, can be reinforced by any appropriate means. These include the use of one or more carbon fiber plies, fiberglass integrated during manufacturing, or fiberglass positioned and fixed above and below in a ring shape around the notch, or aluminum strips.As will be explained below, the presence of a crescent-shaped guard around the rear wheel also helps to reinforce the walls of the notch.

[0036] It is also advantageous for the upper surface 10 to be treated appropriately to ensure good grip for the user's feet. Indeed, during use, intense lateral forces are exerted on the soles of the shoes. To this end, this upper surface can be coated with two different grits of sand embedded in a resin. A coarse grit will provide optimal grip for the user's feet, while a much finer grit will allow the user to grip the platform with their hands. Alternatively, a self-adhesive abrasive paper can be applied.

[0037] The front wheel 3, of a type known per se, comprises a body 30 equipped, for example, with two bearings. This body has a transverse recess for receiving a physical axle 32. Furthermore, it is surrounded by a bearing element 34, for example, made of a polyurethane-type plastic. The front wheel is pivotally mounted on a support 4, around a transverse geometric axis denoted A3 (see in particular Figure 4). This support, also of a type known per se, comprises a base 40 extended by forks 42 and 44, between which the wheel 3 is received. The physical axle 32 extends between the free ends of the forks, being held in place by conventional fasteners such as screws, washers, and nuts.

[0038] The support is rotatably mounted on a bearing 5, which is fixed to the lower surface 11 of the platform 1. This bearing includes a flange 50, inclined relative to this surface 11, which secures the support. This flange 50, forming an inclined base, is extended forward by an additional flange 52, called a connecting flange, which is also inclined. These flanges 50 and 52 terminate, at the front and rear ends of the support respectively, by tabs 54 and 55. These tabs allow the bearing 5 to be fixed to the surface 11 by any suitable means, in particular by screwing. Advantageously, as will be detailed below, shims 56 and 57 of different heights can also be interposed between the lower surface 11 and the tabs 54 and 55. These shims are preferably cylindrical to ensure proper positioning.

[0039] The base 40 of the support 4 is extended, opposite the forks, by a rod 46 that penetrates the mounting flange 50. In operation, the support is free to rotate, relative to the bearing 5, around a geometric axis denoted A4. This rotation is advantageously ensured by two ball bearings, indicated by the dashed arrow 47 in Figure 4, which prevents friction and limits any potential backlash. As shown in particular in Figure 3, this axis of rotation of the support is oblique when viewed from the side, that is to say, it forms a non-zero angle with the vertical. As a less preferred alternative, the angle of rotation A4 can be extended vertically. In a top view, the axis of rotation A4 is essentially coincident with the median longitudinal axis of the platform, so the front wheel 3 is referred to as the median wheel.

[0040] The rear wheel 6 comprises a hub 60, equipped, for example, with two bearings, which has a transverse recess for receiving a physical axle 61 (see, in particular, Figures 6, 7, and 11). This hub is surrounded by a rim 62, with spokes 63 in between. The rolling element 64 can be similar to that 34 of the front wheel, namely made of plastic. However, as an advantageous alternative, this rolling element can be inflatable. In this respect, all suitable variants can be provided, for example, an inner tube working with a tire, a tubular tire, or even a tubeless tire.

[0041] This rear wheel 6 is inserted into the notch 2 described above. The bearing 64, as well as the front 22, rear 23, and lateral 24, 25 walls of the notch, are shown in Figure 7, which depicts these elements from below. When viewed from above, as indicated by arrow VI in Figure 6, the wheel 6 extends approximately along the median longitudinal axis of the platform. Therefore, like the front wheel, this rear wheel is called a median wheel. In other words, the front and rear wheels are aligned along the aforementioned median longitudinal axis A1.

[0042] The mounting of the board 1 onto the rear wheel 6 is achieved by means of two identical brackets 7 arranged symmetrically on either side of the median axis A1, one of which is particularly visible in Figure 6. This bracket 7 comprises a base 70, horizontal in operation, extended by a perpendicular flange 71, which is therefore vertical in operation. In the embodiment shown in Figure 6, which is also schematically illustrated in Figure 8, the base 70 is fixed to the upper surface 10 of the platform.

[0043] To this end, the platform is pierced with through passages 19, visible in particular in Figure 7, which are arranged one behind the other near the side wall 24 of the notch. Screws 72 penetrate each passage, the head 73 of each screw pressing the base 70 against the upper surface 10. On the opposite side, the end 74 of each screw is held against the lower surface 11 by means of a washer 79 and a nut 75, respectively. As an alternative (not shown), a reinforcing plate, typically made of aluminum, can be inserted between each washer and the wall opposite the platform.

[0044] Referring to Figure 6, the aforementioned physical axis 61 extends through the flanges 71 of each bracket 7, being fixed to them by screws. The wheel 6 has a single degree of rotational freedom relative to the platform, about a transverse axis A6 which is substantially perpendicular to the longitudinal axis A1. Unlike the wheel 3, the rear wheel 6 is not a steering wheel, and is therefore called a "fixed wheel" in that its geometric axis of rotation A6 is fixed relative to the platform.

[0045] In accordance with a particularly advantageous aspect of the invention, the above means allow the rear wheel 6 to be mounted on the platform 1 in three different configurations. The advantages specific to this embodiment will be detailed later. The preceding text describes a positioning of the axle A6 above the upper surface 10 of the platform.

[0046] As a first variant, axis A6 can be provided to extend below the lower surface 11 of the platform. To this end, as schematically illustrated in Figure 10, each base 70 is fixed against this lower face. Furthermore, each flange 71 extends downwards, that is, opposite the lower surface 11.

[0047] As a further variant, the axis A6 can be provided to extend within the thickness of the platform, namely between the upper surface 10 and the lower surface 11. For this purpose, as schematically illustrated in Figure 9, each base is fixed against the lower face 11 in a manner analogous to that described with reference to Figure 10. However, unlike the variant in Figure 10, each flange 71 extends upwards in Figure 9, i.e., within the thickness of the platform. In this case, as shown in Figure 11, the side walls of the notch 2 are recessed to receive the flanges 71, as well as the opposite ends of the physical axis 61. In Figure 11, the recess 26 in the side wall 25 is referenced.

[0048] Advantageously, the skateboard according to the invention can be equipped with a braking system designated as a whole by reference numeral 8. This braking system can be, firstly, a disc brake with a caliper, or a regenerative electric brake in the case of a battery-powered model, or even a rim brake. This braking system, shown schematically in Figure 12, comprises, in the illustrated example, opposing brake shoes 80 and 81, known per se, for example, of the type known as "V-brakes" used on mountain bikes. These shoes, equipped with brake shoes 82 and 83 adapted to lock the rim of the rear wheel 6, can be operated by a cable 84 sliding in a sheath 88. This cable is actuated by a handle 86, advantageously held on the board by a clamp 85 of a type known per se.Finally, a plate 87 allows the cable to be fixed to a band not shown, itself secured for example above the user's knee.

[0049] According to the invention, the following combination of parameter values, denoted K1, significantly improves the behavior of the skateboard I, particularly in terms of stability and maneuverability. In this regard, with reference to Figure 3, this combination is as follows: diameter (d) of the front wheel 3 between 40 mm and 150 mm; diameter D of the rear wheel 6 between 100 mm and 400 mm; ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel between 1.25 and 7.

[0050] According to an advantageous feature of the invention, the following combination of parameter values, denoted K2, allows for a particularly significant improvement in the performance of the skateboard I. In this regard, this preferred combination is as follows: diameter (d) of the front wheel 3 between 50 and 130 mm; diameter D of the rear wheel 6 between 140 and 320 mm; ratio (D / d) between 1.8 and 5. According to a particularly advantageous feature of the invention, the following combination of parameter values, denoted K3, allows for a particularly significant improvement in the performance of the skateboard I. In this regard, this particularly preferred combination is as follows: diameter (d) of the front wheel 3 between 60 and 80 mm; diameter D of the rear wheel 6 between 165 and 250 mm; ratio (D / d) between 2.5 and 3.5.

[0051] The combinations of values ​​above, K1, particularly K2, and even more particularly K3, are accompanied by the following technical effects. The larger diameter fixed rear wheel, combined with the smaller diameter front steering wheel, provides both very satisfactory stability and excellent maneuverability on most types of surfaces. This combination also allows for significant responsiveness during acceleration, particularly due to the rigidity of the rear axle. The rider can also make changes of angle smoothly and stably thanks to the support of the front wheel.

[0052] Advantageously, the difference in height (DH) between the transverse axis A6 of rotation of the rear wheel and the upper face 10 of the platform is between +35 mm and -55 mm, more specifically between +30 mm and -50 mm, and even more specifically between 25 mm and -45 mm. When this difference is negative, it means that the axis A6 is located below the upper face 10.

[0053] In terms of overall performance, the skateboard according to the invention allows for steep cornering angles, even at low speeds, as well as near-zero turns. This is because the rear wheel, positioned close to the user's center of gravity, acts as a pivot. Under normal use, the rear wheel supports approximately 70% of the weight. However, by moving the user's center of gravity further back, the rear wheel supports almost the entire weight, which, thanks to its large diameter, allows riding even on uneven surfaces. Consequently, the smaller diameter front wheel does not hinder smooth rolling, while still enabling fluid and precise turns, thus ensuring longitudinal stability.Furthermore, the skateboard according to the invention allows users to perform not only wide, carving-type turns, but also figure-eights in a very small area, all while keeping the wheels firmly planted on the ground. The skateboard according to the invention provides the user with a particularly satisfying gliding sensation on a wide variety of surfaces. Thus, this skateboard can be used like a skateboard or a surfboard in a bowl, ramp, skate park, or pump track. This board is also advantageously suited for use on wide sidewalks, bike paths, and downhill slopes, as well as in confined spaces such as a garage or parking lot.It should be noted that, thanks to its architecture, it is possible to easily maintain the speed of this board and to go up slopes by performing the movements that surfers perform with ease by riding the waves.

[0054] The large diameter of the single, fixed rear wheel creates a gyroscopic effect. This effect is even more pronounced at higher speeds, ensuring excellent stability and directional control. Thanks to its large diameter, it's possible to ride on this single rear wheel, enabling spectacular maneuvers similar to a "foil" effect. This large rear wheel also generates minimal friction with the ground.

[0055] Furthermore, the single, large-diameter rear wheel allows for a particularly wide pitching angle, up to 35° to both the right and left. This enables the user to lean into tight turns without the rear wheel interfering with the platform's underside. It also prevents the user from falling if the rear wheel locks up. Such a feature is not available on most earlier skateboards or surfboards.

[0056] It should also be noted that the large diameter of this rear wheel allows the board equipped with it to travel on surfaces, such as dirt roads, that are impractical for a conventional vehicle. This advantage is particularly significant in the version using an inflatable rear wheel. In this case, it is possible either to reduce the pressure to dampen vibrations or to increase the pressure to improve performance.

[0057] Advantageously, the rear wheel 6 has a diameter of approximately 200 mm. A larger diameter, up to 350 mm, falls within the scope of the invention. Shorter users can then maintain a comfortable posture without having to spread their legs excessively. Conversely, smaller rear wheels with a diameter of up to 120 mm are also possible. In this case, the perimeter of the notch 2 must be reinforced proportionally to the wheel diameter, as the reduced material in the platform becomes increasingly significant.

[0058] The presence of the bearing, which articulates the front wheel, allows the platform to be tilted from right to left along its axis by the user's feet, while simultaneously shifting the support point and thus shifting the center of gravity of the front wheel by a few centimeters. This improves balance at low speeds and even when stationary. Preferably, the radius of the rear wheel is close to the difference in height between the lower surface of the platform and the ground. This difference in height corresponds to the diameter of the smaller wheel plus a portion of the height of the support and the bearing. In this way, the platform is essentially level with the ground, at least in the intermediate region 12. As an advantageous, but not limiting, example, a rear wheel 6 with a diameter of 200 mm works in this way with a front wheel whose diameter is between 60 and 80 millimeters.It should also be noted that such values ​​are found for both front and rear wheels, which are commonly available commercially.

[0059] Providing for the rear wheel to be mounted on the platform, according to different possible altitudes, confers specific technical advantages.

[0060] Generally, the higher the center of gravity of platform 1, the greater the sensation of instability, as well as the range of motion and travel. This allows the user to exercise their sense of balance, enabling the board according to the invention to reproduce the discipline known as "foil surfing." That being said, the configuration in Figure 10 is considered "expert" in that it allows the platform to be raised. In this case, the difference in altitude defined above, denoted DH1 in Figure 10, is negative. To keep the platform level with the ground, thick shims 57 are advantageously placed between the support 5 and the lower surface 11 of this platform.

[0061] Conversely, the lower the center of gravity, the greater the stability and responsiveness for launching, the sensation becoming similar to surfing or snowboarding in powder snow. The configuration shown in Figures 6 and 8 is therefore the most accessible, particularly in terms of user balance. In this case, the difference in altitude defined above, labeled DH2 in Figure 8, is positive. Consequently, there is no need to insert shims between level 5 and the platform.

[0062] Finally, the configuration in Figure 9 is considered "intermediate," in that the user can find a satisfactory compromise between ease of use, gliding sensations, and the overall aesthetics of the board according to the invention. In this case, the difference in heights defined above, denoted DH3 in Figure 9, is very slightly negative since the axis A6 is located immediately below the upper surface 10. In order to keep the platform level with the ground, thin wedges 56 are advantageously inserted between the platform 5 and the lower surface 11 of this platform.

[0063] It should be noted that, particularly advantageously, the same mechanical assembly methods allow for the creation of all three configurations described above. Therefore, depending on the user's progress, it is possible to create versions of the board that are appropriate for each level of skill development, without having to invest in expensive additional equipment. In fact, it will then only be a matter of changing the screw lengths, the shim sets, and the aluminum plywood.

[0064] Structurally, in the case of Figure 8, it is preferable to position the plywood on the opposite side, namely on the underside of the board. This allows the screws, along with the brackets, to sandwich the board, preventing the screws from being pulled out during prolonged use. Conversely, when the brackets are mounted on the underside of the board, the plywood is not necessary.

[0065] Advantageously, the length L12 of the intermediate region, or wheelbase, is between 310 and 750 mm, preferably between 400 and 600 mm. This length corresponds to the distance between, on the one hand, the pivot point P3 of the front wheel 3 on the bearing 4 and, on the other hand, the axis of rotation A6 of the rear wheel.

[0066] Furthermore, also advantageously: the distance between the transverse axis and the rear edge, which corresponds to the length L15 of the rear region 15, is between 100 and 500 mm, preferably between 240 and 330 mm; and / or the distance between the pivot point of the front wheel on the fixed bearing and the front edge, which corresponds to the length L13 of the front region 13, is between 15 and 250 mm, preferably between 50 and 110 mm; and / or the total length (L1) of the board is between 500 and 1300 mm, preferably between 700 and 1000 mm; and / or

[0067] - the total width (11) of the board is between 160mm and 360mm, preferably between 200mm and 300mm.

[0068] The short wheelbase provides noticeable responsiveness. In particular, the user can climb slopes without having to put their feet down, just before descending them.

[0069] Advantageously, the angle of inclination (a4) with respect to the vertical, around the fixed bearing 5, of the axis of rotation A4 of the support 4 of the front wheel, is between 10 and 40°, preferably between 16 and 33°.

[0070] When the lean angle is low, the board can veer off course without affecting its lateral tilt: while it may be more difficult for the rider to maintain their direction, it will be easier to make U-turns. Conversely, with a higher lean angle, the rider will need to press their feet on the right or left side of the board to steer the front wheel in order to turn, or pump to generate speed. A higher lean angle also results in greater responsiveness: for example, with a 30° lean angle, the turning radius is approximately 1.35 m with the rear wheel remaining aligned, meaning without slipping.

[0071] The skateboard according to the invention is very simple to manufacture and assemble, which helps to keep costs down. Essentially, few parts are needed to make this board, particularly parts that are readily available commercially. The board according to the invention is also mechanically reliable and easy to maintain.

[0072] The braking system, which is an advantageous option, allows the user to slow down and stop while remaining in a straight line. This braking capability is particularly useful when the user does not have sufficient width to make wide turns to slow down. According to an advantageous embodiment of the invention, with reference to Figure 3, a guard 90 can be provided, extending around the periphery of at least a portion of the rear wheel 6. This crescent-shaped guard 90 is designed to prevent contact between any foreign object and the upper part of the wheel, while also limiting accidental contact between the user and the rotating rear wheel. This guard provides an additional reinforcing function by improving the mechanical strength of the walls of the notch 2.

[0073] A central carrying handle, either a strap or a rigid one, can also be provided. This handle 92 is particularly advantageous because it can be fixed at one end to the platform, along its median axis, and at its opposite end to the protective element 90 mentioned above.

[0074] The invention is not limited to the examples described and shown.

[0075] First, a motorized version of the skateboard according to the invention can be planned. Preferably, an electric motor will be housed in the hub of the rear wheel.

[0076] A cutout, serving as a handle, can be incorporated into one side of the board, positioned near its center of gravity. This allows the board to be gripped manually while remaining horizontal. Furthermore, it allows the board to be secured with a padlock.

[0077] Advantageously, the platform's perimeter can be equipped with various protective elements, for example, made of a hard plastic material. These interchangeable protective elements prevent premature wear when the platform rubs against the ground.

[0078] As an additional option, two flanges can be fitted on either side of the rear wheel. Their function is to secure the user's fingers when they wish to grip the board, in case the rear wheel is still moving.

[0079] The skateboard according to the invention can also be equipped with a lighting device, for example, a lamp positioned towards the front, close to the ground. This allows the user to better perceive irregularities in the road. A suitable audible warning device of any type can also be provided.

[0080] The board according to the invention can be associated with a propulsion aid, which can also serve for balancing. In this case, it is, for example, a paddle-type bar similar to a paddle on a stand-up paddleboard.

[0081] An elastic cord, of the SANDOW type, with a length of approximately 3 to 5 m, can also be used. This allows energy to be created, with the help of an outside person, by rotating around them.

[0082] The front wheel can be equipped with a spring system, allowing the wheel to return to its axis when it lifts above the ground.

[0083] Finally, the wheeled board according to the invention can be equipped, at the upper surface of its front part, with a mast foot. This can receive rigging identical to that of a windsurfing board.

Claims

DEMANDS 1. Land vehicle, of the wheeled board type (I) comprising: - a platform (1) defining a median longitudinal axis (A1), corresponding substantially to the direction of movement of the vehicle, said platform comprising an upper face (10), a lower face (11), a front edge (14), a rear edge (16) and lateral sides, - a front steering wheel (3) disposed entirely below the underside of the platform, in use, this front wheel being free to pivot, around a transverse axis (A3), relative to a support (4), which support is mounted for rotation relative to a bearing (5) around an axis of rotation (A4) located substantially on the median longitudinal axis of the platform, in top view, - a rear wheel (6) mounted for rotation relative to the platform about a fixed transverse axis (A6) of this platform, a portion of the rear wheel being located above the upper face of the platform, this rear wheel extending substantially along the median longitudinal axis of the platform so as to be aligned with the front wheel bearing - the diameter (d) of the front wheel being between 40mm and 150mm (millimeters), - the diameter (D) of the rear wheel being between 100mm and 400mm, and - the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel being between 1.25 and 7.

2. Vehicle according to claim 1, the diameter (d) of the front wheel being between 50 and 130 mm, the diameter (D) of the rear wheel being between 140 and 320 mm, the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel being between 1.8 and 5.

3. Vehicle according to claim 2, the diameter (d) of the front wheel being between 60 and 80 mm, the diameter (D) of the rear wheel being between 165 mm and 250 mm, and the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel being between 2.5 and 3.

5.

4. Vehicle according to any one of the preceding claims, wherein the difference in altitudes (DH) between the upper face (10) and the fixed transverse axis (A6) is between +35mm and -55mm, preferably between +30mm and -50mm, even more preferably between +25mm and -45mm.

5. Vehicle according to any one of the preceding claims, further comprising means (7) for mounting the rear wheel on the platform (1), which are adapted to selectively confer several differences in altitudes (DH1 - DH3) between the upper face (10) of the platform and the fixed transverse axis (A6) of rotation of the rear wheel.

6. Vehicle according to the preceding claim, wherein the mounting means comprise at least one bracket and, in particular, two brackets (7) provided on either side of the rear wheel, in top view, each bracket (7) comprising a base (70) adapted to be selectively fixed on the upper or lower face of the platform, as well as a mounting flange (71) for a physical axis of rotation of the rear wheel, adapted to extend selectively upwards or downwards from the base.

7. Vehicle according to the preceding claim, in which the mounting means are adapted to provide three relative configurations between the rear wheel and the platform, namely - a raised rear wheel configuration, in which the base is fixed to the upper face and the mounting flange extends upwards - a lowered rear wheel configuration, in which the base is fixed to the underside and the mounting flange extends downwards - an intermediate rear wheel configuration, in which the mounting flange extends into the thickness of the platform.

8. Vehicle according to any one of the preceding claims, in which the rear wheel extends through a notch (2) formed in the platform, said notch being bordered by opposing front, rear and side walls respectively, reinforcement means being advantageously provided at the level of at least a part of said walls, 9. Vehicle according to the preceding claim, in which the notch is hollowed out with a recess (26) allowing the reception of at least a part of the mounting means, in said intermediate configuration.

10. Vehicle according to any one of claims 5 to 9, further comprising a set of shims (56,57) of different heights, suitable for being interposed between the bearing (5) of articulation of the front wheel and the lower face (11) of the platform.

11. Vehicle according to any one of claims 5 to 10, in which the distance (L12) or wheelbase between, on the one hand, the articulation point of the front wheel on the fixed bearing and, on the other hand, the axis of rotation of the rear wheel is between 310 mm and 750 mm, preferably between 400 and 600 millimeters.

12. Vehicle according to any one of claims 5 to 11, wherein the angle of inclination (a4), with respect to the vertical, of the axis of rotation (A4) of the support (4) of the front wheel (3) with respect to the fixed bearing, is between 10 and 40°, preferably between 16 and 33°.

13. Vehicle according to any one of claims 5 to 12, wherein the distance (L15) between the transverse axis and the rear edge is between 100 and 500 mm, preferably between 240 and 330 mm.

14. Vehicle according to any one of claims 5 to 13, wherein the distance (L13) between the articulation point of the front wheel on the fixed bearing and the front edge is between 15 and 250 mm, preferably between 50 and 110 mm.

15. Vehicle according to any one of claims 5 to 14, wherein the total length (L1) of the board is between 500 and 1300 mm, preferably between 700 and 1000 mm, while the total width (11) of the board is between 160 mm and 360 mm, preferably between 200 mm and 300 mm.

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