Land vehicle, of the skateboard type

Abstract

This vehicle includes a platform (1), a front steering wheel (3) disposed entirely below the platform, free to pivot about a transverse axis (A3), relative to a support (4) mounted for rotation about a bearing (5) along the median longitudinal axis of the platform, and a rear wheel (6) mounted for rotation about the platform around 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 being aligned with the bearing of the front wheel. Furthermore, the diameter (d) of the front wheel is between 40mm and 150mm, the diameter (D) of the rear wheel between 100mm and 400mm, and the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel between 1.25 and 7. The skateboard according to the invention exhibits both satisfactory stability and great maneuverability in use, on many types of surfaces.It allows its user to perform a variety of figures, it is simple and reliable in design, while being inexpensive to produce and maintain, and it has a modular structure, allowing it to adopt different configurations depending in particular on the user's level. Figure for the abbreviation: [Fig. 1].

Description

Title of the invention: Land vehicle, of the wheeled board type Technical field of the invention

[0001] The invention relates to the technical field of skateboards, or wheeled skateboards. These land vehicles are designed to transport a user, whether in an urban or natural environment, for sporting or recreational activities. Such skateboards allow users to reproduce the gliding sensations they might experience while practicing on water or snow. State of the art

[0002] The prior art includes numerous wheeled boards or casters, among which we will first mention those comprising a platform, either flexible or rigid, combined with two small front and rear steering wheels. This solution, however, generates both instability on most surfaces and, moreover, discomfort on degraded surfaces. Furthermore, the rear steering wheel, that is to say, the wheel that rotates relative to the platform around a vertical or oblique axis, does not allow for the desired dynamism in practice.

[0003] In particular, the skateboards described in WO 2009 / 156983, WO 2015 / 119304 and WO2023 / 056340 allow the user to turn thanks to their two movable wheels, and also to make 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 the lateral supports are engaged during the aforementioned pelvic movements. This tends to accentuate the turns, which consequently limits the acceleration.

[0004] Prior art documents WO 2007 / 127554 (flexible monocoque 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 paragraph. As such, they share the same drawbacks as boards conforming to the three documents in the preceding paragraph. 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.

[0005] Two or three wheels, being small, are also quickly limited on uneven surfaces. The five planks above do not allow for easy launching into a bowl or ramp, or even into a ramp by pushing off the rear. of the board by performing the maneuver called "drop". Indeed, the user's rear foot is then positioned above the moving rear wheel.

[0006] 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 slight travel) present, due to their small diameter wheels, the same drawback on uneven surfaces. Furthermore, the rear truck does not allow for significant lean angles, due to the wheels interfering with the underside of the board.

[0007] US patents 7,172,205 and FR 2,881,059 should also be cited, as they describe boards incorporating the main characteristics and, consequently, the drawbacks of the first three boards mentioned above. These alternative solutions include additional wheels positioned laterally. This solution limits the angle of attack during use, thus reducing the overall maneuverability of the board.

[0008] Finally, we will cite US 2023 / 00493317, which discloses a board supposedly designed to simulate the feel of a "longboard." To this end, this document instructs users to use a two-wheeled skateboard truck at the rear. The resulting board has a complex structure, yet is not very maneuverable. This restricts its use to large spaces and prevents its use in features such as a bowl, a ramp, a skatepark, or a pumptrack.

[0009] In view of the foregoing, the invention addresses various disadvantages of the prior art mentioned above.

[0010] 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.

[0011] It also aims to offer such a board, which allows its user to perform various figures, including "drop" type, curves, "carving", "wheeling" or even half turns on the spot.

[0012] It also aims to offer such a board, which is of simple and reliable design, while being inexpensive to produce and then to maintain.

[0013] It aims finally to propose such a board which has a modular structure, allowing it to adopt different configurations depending in particular on the level of the user.

[0014] Objects of the invention

[0015] According to the invention, at least one of the above objectives is achieved by means of a wheeled board type vehicle (I) comprising

[0016] a platform (1) defining a median longitudinal axis (Al), corresponding substantially to the direction of travel of the vehicle, said platform comprising an upper face (10), a lower face (11), a front edge (14), a rear edge (16) and side edges,

[0017] 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 to rotate relative to a bearing (5) around an axis of rotation (A4) located substantially on the median longitudinal axis of the platform, in top view,

[0018] 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

[0019] the diameter (d) of the front wheel being between 40mm and 150mm (millimeters),

[0020] the diameter (D) of the rear wheel being between 100mm and 400mm, and

[0021] the ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel being between 1.25 and 7.

[0022] According to other features, 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 165mm 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 altitude (DH) between the upper face (10) and the fixed transverse axis (A6) is between +35mm and -55mm, preferably between +30mm and -50mm, and 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 differences in height (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) suitable for being 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, capable of selectively extending 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 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 the rear wheel extends through a notch (2) formed in the platform, said notch being bordered by opposing front, rear and lateral walls respectively, with reinforcement means 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 part of the mounting means, in said intermediate configuration, the vehicle further includes a set of shims (56, 57) of different heights, suitable for being interposed between the front wheel articulation bearing (5) and the underside (11) of the platform, 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, 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 bearing, 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 fixed bearing and the front edge is between 15 and 250 mm, preferably between 50 and 110 mm. The total length (Ll) 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. Description of the figures

[0023] The invention will be described below, with reference to the accompanying drawings, given solely by way of non-limiting examples, in which:

[0024] [Fig-1] is a perspective view, illustrating a skateboard according to the invention, viewed from above.

[0025] [Fig.2] is a view from below, illustrating this same skateboard.

[0026] [Fig.3] is a side view, illustrating this skateboard and its dimensions features.

[0027] [Fig.4] is a perspective view, illustrating a support for the front wheel of the plate of the preceding figures.

[0028] [Fig. 5] is a side view, illustrating on a larger scale the articulation of this wheel forward on the platform of the board.

[0029] [Fig.6] is a perspective view, illustrating on a larger scale the assembly of the rear wheel on the board platform.

[0030] [Fig.7] is a perspective view, illustrating from another angle the assembly of the rear wheel of the [Fig.6].

[0031] [Fig.8] is a schematic side view, illustrating a first configuration functional of the skateboard according to the invention.

[0032] [Fig.9] is a schematic side view, analogous to [Fig.8], illustrating another functional configuration in which the platform altitude is different.

[0033] [Fig. 10] is a schematic side view, analogous to figures 8 and 9, illustrating yet another functional configuration in which the platform height is yet different.

[0034] [Fig. 11] is a view along arrow XI in [Fig.9], illustrating the interior of the platform as well as various mechanical elements housed in this platform.

[0035] [Fig. 12] is a schematic view, illustrating different components of the braking system that can be fitted to the skateboard according to the invention. Detailed description

[0036] The skateboard according to the invention, which is designated as a whole by reference I, essentially comprises a platform 1, a single front wheel, a single rear wheel, and means for mounting and articulating these wheels on this platform.

[0037] The platform 1, generally rectangular when viewed from above, has a median longitudinal axis denoted AL. It comprises an upper surface 10 and a lower surface 11, with reference 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. shape which is terminated by a rear edge 16. The respective ends of regions 12, 13 and 15 will be specified below. Finally, 17 and 18 are the opposite lateral sides of the platform.

[0038] The platform material can be of any suitable type, particularly suitable for the conventional manufacture of skateboards. Examples include wood, any plastic material obtained by molding or 3D printing, and composite fibers. Preferably, layers of wood can be glued and then compressed using a press. As shown in particular in [Fig. 3], the rear region is raised while the front region has a slight concavity. During manufacturing, to ensure these shapes are present, the wooden deck plates can be held in place by means of blocks or a mold.

[0039] As can be seen in particular in Figures 6 and 7, a notch 2 is formed in the platform 1, symmetrical with respect to the median longitudinal axis AL. This notch, allowing the passage of the rear wheel as described below, creates a material shortage. Consequently, it is advantageous to reinforce the platform by using a slightly greater number of wood layers than that used in the usual construction of skateboards. For example, eight or nine wood layers can be used to make the platform 1.

[0040] Furthermore, the peripheral walls of the notch 2, which allows passage of the rear wheel 6, can be reinforced by any suitable means. These include, in particular, 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 this notch, or even 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.

[0041] 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. For this purpose, this upper surface can be coated with two different grains of sand embedded in a resin. A coarse grain will provide optimal grip for the user's feet. Furthermore, a much finer grain will allow the user to grip the platform with their hands. Alternatively, a self-adhesive abrasive paper can be applied.

[0042] 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 rolling element 34, for example, made of a polyurethane-type plastic material. The front wheel is pivotally mounted on a support 4, around a transverse geometric axis denoted A3 (see in particular [Fig.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 axis 32 extends between the free ends of the forks, being held by means of conventional screw, washer and nut systems.

[0043] The support is rotatably mounted on a bearing 5, which is integral with 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, 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, 57 of different heights can also be interposed between the lower surface 11 and the tabs 54, 55. These shims are preferably cylindrical to ensure proper positioning.

[0044] 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 [Fig. 4], which avoids friction and limits any potential backlash. As shown in particular in [Fig. 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.

[0045] 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 interposed between them. 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 cooperating with a tire, a tubular tire, or even a tubeless tire.

[0046] This rear wheel 6 is inserted into the notch 2 described above. The rolling element 64, as well as the front 22, rear 23 and lateral 24, 25 walls of the notch, are shown in [Fig. 7], which represents these different elements seen from below. When viewed from above, according to arrow VI shown in the [Fig. 6], wheel 6 extends substantially along the median longitudinal axis of the platform. Consequently, like the front wheel, this rear wheel is called the median wheel. Put another way, the front and rear wheels are aligned along the aforementioned median longitudinal axis A1.

[0047] 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 Al, one of which is particularly visible in [Fig. 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 of [Fig. 6], which is also schematically illustrated in [Fig. 8], the base 70 is fixed to the upper surface 10 of the platform.

[0048] To this end, the platform is pierced with through passages 19, visible in particular in [Fig. 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 relative to 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.

[0049] With reference to [Fig. 6], the aforementioned physical axis 61 extends through the flanges 71 of each bracket 7, being fixed to them by screws. There is a single degree of rotational freedom of the wheel 6 relative to the platform, about a so-called transverse axis A6 which is substantially perpendicular to the longitudinal axis A1. Unlike the wheel 3, the rear wheel 6 is not of the steering type, and is therefore called a "fixed wheel" in the sense that its geometric axis of rotation A6 is fixed relative to the platform.

[0050] 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.

[0051] As a first variant, the axis A6 may be provided to extend below the lower surface 11 of the platform. To this end, as schematically illustrated in [Fig. 10], each base 70 is fixed against this lower face. Furthermore, each flange 71 extends downwards, namely opposite the lower surface 11.

[0052] As a further variant, axis A6 may be provided to extend through the thickness of the platform, namely between the upper surface 10 and the lower surface 11. For this purpose, as schematically illustrated in [Fig. 9], each The base is fixed against the lower face 11 in a manner analogous to that described with reference to [Fig. 10]. However, unlike the variant in [Fig. 10], each flange 71 extends upwards in [Fig. 9], that is, into the thickness of the platform. In this case, as shown in [Fig. 11], the side walls of the notch 2 are recessed to receive the flanges 71, as are the opposite ends of the physical axis 61. In [Fig. 11], the recess 26 in the side wall 25 is referenced.

[0053] 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, schematically illustrated in [Fig. 12], comprises firstly opposing brake shoes 80 and 81, known per se, for example, of the type known as "V-brakes" fitted to a mountain bike. These shoes, provided with pads 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 attached to a band (not shown), itself secured, for example, above the user's knee.

[0054] According to the invention, the following combination of parameter values, denoted Kl, significantly improves the behavior of the skateboard I, particularly in terms of stability and maneuverability. In this regard, with reference in particular to [Fig. 3], this combination is as follows: • diameter (d) of the front wheel 3 between 40mm and 150mm (millimeters) • Rear wheel diameter D 6 between 100mm and 400mm • ratio (D / d) between the diameter of the rear wheel and the diameter of the front wheel between 1.25 and 7.

[0055] According to an advantageous feature of the invention, the following combination of parameter values, denoted K2, makes it possible to significantly improve the behavior of the skateboard I. In this regard, this preferred combination is as follows: • diameter (d) of the front wheel 3 between 50 and 130mm • Rear wheel diameter D 6 between 140 and 320mm • ratio (D / d) between 1.8 and 5.

[0056] According to a particularly advantageous feature of the invention, the following combination of parameter values, denoted K3, makes it possible to significantly improve the behavior 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 • Rear wheel diameter D 6 between 165 and 250 mm • ratio (D / d) between 2.5 and 3.5.

[0057] The above value combinations, Kl, more 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 steering front wheel, provides both very satisfactory stability and excellent maneuverability in use on most types of surfaces. This combination also allows for significant responsiveness during acceleration, particularly due to the rigidity of the rear axle. The user can also make changes of angle smoothly and stably thanks to the support of the front wheel.

[0058] 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 particularly between +30 mm and -50 mm, and even more particularly between 25 mm and -45 mm. When this difference is negative, it means that the axis A6 is located below the upper face 10.

[0059] In terms of general behavior, 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 virtually all of the 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 allowing for fluid and precise turns, thus ensuring longitudinal stability.Furthermore, the skateboard according to the invention allows not only large "carving" type curves, but also "figure-eight" type figures in a very small area, while keeping the wheels pressed against the ground.

[0060] The skateboard according to the invention allows the user to experience a particularly satisfying gliding sensation on a variety of surfaces. Thus, this skateboard can be used like a skateboard or a surfboard in a bowl, on a ramp, in a skate park, or even on a pump track. This board is also advantageously suited for use on wide sidewalks, bike paths, and downhill, as well as in confined spaces such as a garage or parking space. It should be noted that, thanks to its design, it is easy to maintain the board's speed and to climb slopes by performing the same movements that surfers effortlessly execute while riding waves.

[0061] The large diameter of the single, fixed rear wheel provides a gyroscopic effect. This phenomenon is all the more pronounced at higher speeds, ensuring high stability and good directional control. Thanks to its large diameter, it is possible to ride on this single rear wheel, enabling spectacular maneuvers similar to a "foil" effect. This large rear wheel also generates little friction with the ground.

[0062] 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 underside of the platform. It also prevents the user from falling if the rear wheel locks up. This feature is not available in most prior art skateboards or surfboards.

[0063] It should also be noted that the large diameter of this rear wheel allows the board equipped with it to move on surfaces, such as dirt roads, which are impractical for a conventional vehicle. This advantage is particularly significant in the embodiment using an inflatable rear wheel. Indeed, in this case, it is possible either to reduce the pressure to further dampen vibrations, or to increase the pressure to improve performance.

[0064] 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 position without having to spread their legs excessively. Conversely, smaller rear wheels with a diameter of up to 120 mm can also be used. 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.

[0065] The presence of the bearing, which articulates the front wheel, allows the pivot point of the latter to be moved, thus improving balance at low speeds, or even when stopped. 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 small wheel, plus a portion of the height of the support and the bearing. In this way, the platform is substantially 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 cooperates in this respect with a front wheel whose diameter is between 60 and 80 mm. millimeters. It should also be noted that such values ​​are found for both front and rear wheels, which are commonly available commercially.

[0066] Providing for the rear wheel to be mounted on the platform, according to different possible altitudes, confers specific technical advantages.

[0067] Generally, the higher the center of gravity of the platform 1 is raised, the greater the sensation of instability, as well as the distances and ranges of motion. This allows the user to exercise their sense of balance, which enables the board according to the invention to reproduce the discipline known as "foil surfing." That being said, the configuration of [Fig. 10] is described as "expert" in that it allows the platform to be raised. In this case, the difference in altitude defined above, denoted DH1 on [Fig. 10], is negative. In order to keep the platform level with the ground, thick wedges 57 are advantageously placed between the support 5 and the lower surface 11 of this platform.

[0068] Conversely, the lower the center of gravity, the greater the stability and responsiveness for launching, the sensation then being 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 balance for the user. In this case, the difference in altitude defined above, denoted DH2 in [Fig. 8], is positive. There is therefore no need to insert wedges between level 5 and the platform.

[0069] Finally, the configuration of [Fig. 9] is described as "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 on [Fig. 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.

[0070] It should be noted that, particularly advantageously, the same mechanical assembly means allow for the creation of the three configurations described above. Consequently, depending on the user's progress, it is possible to create versions of the board that are appropriate for each level of this progression, without having to invest in expensive additional equipment. Indeed, it will then only be a matter of changing the screw lengths, the sets of shims, and the aluminum plywood.

[0071] Structurally, in the case of [Fig. 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 at the level of the underside of the board, plywood is not required.

[0072] 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 articulation 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.

[0073] 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 (Ll) of the board is between 500 and 1300 mm, preferably between 700 and 1000 mm; and / or - the total width (11) of the board is between 160mm and 360mm, preferably between 200mm and 300mm.

[0074] The short wheelbase provides appreciable responsiveness. In particular, the user is able to climb slopes without having to put their foot down, just before descending them.

[0075] 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°.

[0076] When the angle of inclination is low, the board can deviate without affecting its lateral tilt: although it is more difficult for the user to maintain their course, it will be easier to make U-turns. Conversely, with a higher angle, the user will have 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 high angle is accompanied by greater responsiveness: for example, with an inclination of 30°, the turning radius is approximately 1.35 m with the rear wheel kept aligned, i.e., without skidding.

[0077] The skateboard according to the invention is very simple to manufacture and assemble, which helps to limit costs. In essence, few parts are needed to manufacture this board, in particular parts readily available commercially. The board according to the invention is also mechanically reliable, while being easy to maintain.

[0078] 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.

[0079] According to an advantageous embodiment of the invention, with reference to [Fig. 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 body 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.

[0080] A central carrying handle, either a strap or a rigid handle, can also be provided. This handle 92 is particularly advantageous and can be fixed at one end to the platform, along its median axis, and at its opposite end to the protection 90 above.

[0081] The invention is not limited to the examples described and shown.

[0082] First, we can plan to produce a motorized version of the skateboard according to the invention. Preferably, an electric motor will be housed in the hub of the rear wheel.

[0083] A cutout, serving as a handle, may be provided on one side of the board, positioned near its center of gravity. This allows the board to be grasped manually while holding it horizontally. Furthermore, it allows the board to be secured with a padlock.

[0084] Advantageously, the periphery of the platform 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.

[0085] As a further variant, two flanges can be provided on either side of the rear wheel. Their function is then to secure the user's fingers when the user wishes to grasp the board, in case the rear wheel is still moving.

[0086] 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 type of audible warning device can also be provided.

[0087] 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.

[0088] An elastic cord, of the SANDOW type, with a length of approximately 3 to 5 m, can also be provided. This makes it possible to create energy, with the help of an external person, by rotating around the latter.

[0089] The front wheel can be equipped with a spring system, allowing this wheel to return to its axis when it lifts above the ground.

[0090] Finally, the wheeled board according to the invention can be equipped, at the level of the upper surface of its front part, with a mast foot. The latter can receive a rigging, identical to that of a windsurfing board.

Claims

Demands

1. A land vehicle, of the wheeled platform type (I) comprising: a platform (1) defining a median longitudinal axis (A1), corresponding substantially to the direction of travel 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 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. A 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 heights (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) capable of being 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, capable of selectively extending upwards or downwards from the base.

7. Vehicle according to the preceding claim, wherein the mounting means are adapted to confer three relative configurations between the rear wheel and the platform, namely - a raised configuration of the rear wheel, in which the base is fixed on the upper face and the mounting flange extends upwards - a lowered configuration of the rear wheel, in which the base is fixed on 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.

8. Vehicle according to any one of the preceding claims, wherein 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, the notch being advantageously hollowed out with a recess (26) allowing the reception of at least a part of the mounting means, in said intermediate configuration.

9. A vehicle according to any one of claims 5 to 8, further comprising a set of shims (56, 57) of different heights, suitable for being interposed between the front wheel articulation bearing (5) and the lower face (11) of the platform.

10. A vehicle according to any one of claims 5 to 9, wherein 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 mm; and / or 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°; and / or the distance (L15) between the transverse axis and the rear edge is between 100 and 500 mm, preferably between 240 and 330 mm; and / or 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; and / or the total length (L1) of the board is between 500 and 1300 mm, preferably between 700 and 1000 mm;and / or 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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