Variable geometry traction device

Abstract

The invention is a traction device for a vehicle, such as a wheel or a track, comprising one or more traction accessories that can change position to transition from a position enabling traction on the ground to a position ensuring traction in or on the surface of a fluid, or even to traction on a slippery surface. The main applications are land vehicles capable of traveling on roads as well as on uneven or muddy terrain and of navigating on or in water, such as a motor vehicle, a boat capable of operating on shallow waters, a submarine, or an aircraft capable of landing on a beach or on the water.

Description

Title of the invention: Variable geometry traction device technical field

[0001] The invention is a vehicle traction device that can adapt to the environment on which or in which it moves, by the use of auxiliary traction accessories such as wings, blades, vanes, anti-slip treads, removable studs and cleats, etc. Previous technique

[0002] CN107962922A of April 27, 2018, by CUI JIE et al., is known, describing a track equipped with a plurality of paddles arranged on the outer end faces of the tracks and which provide traction for an amphibious vehicle in water. These paddles are permanently perpendicular to the outer faces of the tracks, so that they are not well suited to the movement of the vehicle on hard ground and slow the vehicle in their upper part when they encounter water.

[0003] We know of CN108422821 (A) of August 21, 2018 by SUN SHILIANG which describes a similar device and presents the same drawback.

[0004] We know of CN110733305 (A) of January 31, 2020 by WANG XINGBO et al. which describes a blade comprising a plurality of flexible blades ensuring the traction of a vehicle in water, but which is also poorly adapted to the circulation of a vehicle on a hard ground.

[0005] We know of US 10259280 (B 1) of April 16, 2019 by ROE RICHARD DARIN [US] which describes a vehicle equipped with wheels allowing it to roll on a ground, which have on their lateral part paddles to ensure the traction of the vehicle on water, but the efficiency of the drive on water of this device is low.

[0006] CN114619813A of June 14, 2022, from GAO ​​SHENGYUN [CN] is known, describing a four-wheeled amphibious vehicle with paddles that can be periodically deployed and retracted, the switch between a land driving mode and an aquatic driving mode being achieved by rotating the angle of a cam. This vehicle cannot automatically switch to land driving mode upon encountering a solid obstacle, and the paddles cannot all be simultaneously retracted, which poses space constraints.

[0007] We know of WO2007079045A2 of July 12, 2007, from MUNSHAUR TODD [US] and VAN OSDELL STEVEN [US], which describes an amphibious vehicle equipped with floating amphibious traction wheels, the wheels having a number of foldable pockets arranged around the surface of the wheel and oriented in the direction of rotation of the wheel. This vehicle cannot operate in a fluid while reversing, whereas reverse propulsion is the most effective braking method for boats. Furthermore, these pockets gradually fill with all the debris encountered by the vehicle, particularly sand or dirt, and thus lose their effectiveness.

[0008] Numerous documents describing tire studs and spikes are known. All these elements are inherently rigid to penetrate ice, and when retracted, they are either recessed from the tread and not part of its outer surface, which is therefore discontinuous, or they constitute a hard spot on the tread that impairs road holding and quiet operation. Some deploy or retract under the effect of temperature, but other methods are proposed to achieve this deployment and retraction, such as that proposed by US9278584B2 of March 8, 2016, by BUSHNELL RAYMOND B [US] and LARSON BRADLEY KS [US], which describes a plurality of stud actuation chambers contained within a toroidal shell enclosing an air-filled chamber and having an external radial surface. Technical problem

[0009] The objective of the present invention is to enable a vehicle to switch from a configuration allowing energy-saving quality driving, as is permitted with smooth wheels or tracks rolling on a smooth and non-slip surface such as a road or dry path, to another configuration adapted for driving on mud, snow or ice, or even for aquatic traction or aerial traction.

[0010] The problem is complex because the tread must have several possible aspects and therefore include traction accessories which can deploy from their retracted position to their deployed position when necessary to ensure the traction of the vehicle by their pressure on a fluid or on a granular medium such as sand, snow, mud or loose soil, but also retract when they encounter an obstacle such as a fairly hard ground which would be likely to damage them.

[0011] They must not disrupt the operation of the tread by an irregularity in its elasticity.

[0012] They must also allow, on command of a person or a computer, to move from one position to another in a gradual or abrupt manner, to brake and to operate in reverse in all circumstances, and to extract themselves from the mud and to raise the vehicle above the surface of the water to limit its drag, while being compatible with the road holding of conventional tires.

[0013] Finally, advantageously, the device according to the invention should not have a larger footprint than a conventional wheel, and the use of the accessories should not increase the lateral dimensions of the device. Brief description of the drawings

[0014] The invention will be well understood, and other objects, advantages and features thereof will become more apparent from the reading of the description which follows, which is illustrated by figures 1 to 13.

[0015] [Fig. 1] is a perspective view of the components of a wheel according to the invention and of an assembled wheel. On the left, the traction accessories 21, 22, and 23 and following are visible, which are chevron-shaped blades, and whose position is determined by the secondary shaft 40, which is a ring offset relative to the primary shaft 10, thus driving all the blades downwards. On the right, only the blades 24, 25, and 26 are visible, the others remaining enclosed in their housings 210, 220, and 230.

[0016] [Fig.2] is a perspective and cross-sectional view of the wheel of [Fig.1], in which The blades are less far from the axis of rotation 10 of the wheel, which results in them all being set back from the tread, and not limiting the elasticity of the wheel allowing it to absorb the shocks of small obstacles.

[0017] [Fig.3] is also a perspective and cross-sectional view of the wheel of [Fig.1] and of [Fig.2], in which the secondary shaft 40 is offset downwards and forwards (left of the figure), which has the effect that the blades located at the front of the wheel give rise, during the rotation of the propulsion wheel, to a force directed more downwards than on the device shown in [Fig.1] where this force is directed backwards.

[0018] [Fig.4] is a perspective view of two IA wheels whose blades 21 22 and following They are flat and sliding. These traction accessories are vanes on the left and winter tire stud assemblies on the right. Elastic springs 31, 32, and following push them in the direction from their retracted to their deployed position. The wheel is rolling on hard ground, and the lower traction accessories are in the retracted position, while the upper traction accessories are in the deployed position. If this wheel were rolling on mud or fresh snow, the lower traction accessories would be in the deployed position.

[0019] [Fig. 5] is a perspective view of two wheels according to the invention, of which the Housings 210 and following of the traction accessories are attached only to the tread of wheel IA. Like the one shown in the previous figure, this one is particularly suitable for airless tires.

[0020] [Fig.6] is a perspective view of blades 21 22 and following similar to those shown in [Fig.1], each equipped with a bearing, respectively 211 221 and following allowing their position to be determined by cooperation with a concave cam visible in [Fig.7].

[0021] [Fig. 7] is a perspective view of the mechanism that determines the position of the blades according to their position in the rotation cycle of the wheel. Elastic return springs (not shown) push the blades towards their deployed positions, but this movement is limited by the concave cams 401 and / or 402. On the left, the concave cam 402 places them all at an equal distance from the primary shaft 10, while on the right, the concave cam has pivoted 180 degrees and released the blades such that it is the oblong-shaped cam 401 that allows the blades in the lower part of the wheel to be deployed while those in the upper part are not.

[0022] [Fig.8] is a perspective view of a vehicle equipped with paddle wheels according to figures 1, 2, 3 or 6. It is equipped with 4 wheels according to the invention and in addition at the front of an obstacle crossing aid device 70 according to patent application FR3048404A3 of Franck Guigan [FR] of September 8, 2017.

[0023] [Fig.9] is a perspective view of two mechanical sub-assemblies of this vehicle. The one on the left is in hard ground driving mode and all the blades are in the retracted position, while the one on the right is in water driving mode and the lower blades are in the deployed position.

[0024] [Fig. 10] is a perspective view of three IA wheels, the vanes of which 21, 22 and following are tire treads. These traction accessories are: - in the retracted position on the left - a position suitable for low-speed driving - which reduces the surface area of ​​the tread actually in contact with the ground when the traction device is traveling on a flat, hard surface, resulting in significant energy savings and reduced rolling noise; - in the middle position in the center - a position suitable for high-speed driving - which offers the advantages of good grip, good stability in corners, a short braking distance, and high driving comfort, but results in higher fuel consumption; - and in the deployed position on the right, which allows driving on snow or mud.

[0025] [Fig. 11] is a perspective view of four sets of traction accessories that deploy simultaneously. On the left, the wheel IA and the six traction accessories, which are chevron-shaped vanes 21 to 26, are visible through the transparent material. Their deployed position is determined by the position of the hub 400, which can be moved along the wheel's axis of rotation to determine the configuration of the accessories. The wheel 21 is connected to the hub 400 by an articulated arm 2100, and so on for the other 5 blades. The three assemblies on the right represent the blade positions for different positions of this hub, and it can be seen that the blades can be completely retracted, as illustrated by the assembly shown furthest to the right.

[0026] [Fig. 12] is a perspective view of an IA self-propelled wheel according to the invention. It is equipped with a chassis 300, which consists of a rod with a handlebar 301 and two controls 302 and 303. Optionally, a rowlock 304 attached to a vehicle can support the traction forces generated by the rotation of the wheel on the ground or in a fluid or granular medium.

[0027] [Fig. 13] is a perspective view of a track according to the invention. The paddles 21, 22 and following are in the deployed position at the bottom, providing traction on soft ground or on or in water, while those at the top are in the retracted position. The elastic return springs are not shown, but two belts 61 and 62 can be seen forcing the paddles located in the upper part of the track IB to move into the retracted position. Description of the invention

[0028] The invention is a traction device for a vehicle such as a wheel IA or a track IB comprising - a tread, comprising an outer face which is in direct contact with the road when said traction device rolls on a flat road, and an inner face which is separated from said outer surface by the thickness of said tread, which may or may in particular include a ground contact material and a framework commonly called the carcass which ensures its strength and resistance to load, said inner surface defining an inner volume of said traction device, - a plurality of so-called traction accessory elements 21, 22 and following, - and a so-called deployment / retraction mechanism allowing a traction accessory to deploy by sliding within all or part of the thickness of the tread, the sliding taking place along a fixed path in the tread, to move from a so-called retracted position to a so-called deployed position by moving in a direction from the inner face to the outer face, and vice versa, - a traction accessory being located in its retracted position within the volume of which said outer face of said tread is the geometric envelope, characterized in that a traction accessory: - forms, in its deployed position, an outward projection of said tread towards its outer surface, and contributes to the vehicle's traction by its pressure on a fluid or granular medium, - and includes an elastic retraction means 31 allowing its retraction when an obstacle opposes its deployment during the cycle, and that all of said traction accessories can be simultaneously in the retracted position. It being specified that above and below, "to deploy and to retract" means movements of a traction accessory going respectively in the direction from the retracted position to the deployed position and in the opposite direction. Detailed description of the invention

[0029] The principle of the present invention is to equip the tread of a wheel or track with a plurality of traction accessories that can be deployed at the command of a control means to automatically adapt to the medium on or in which the vehicle is moving. For example, a traction accessory is placed in a retracted position when the vehicle is on solid ground such as a road, and in a deployed position when the vehicle is moving either on soft ground such as mud or snow, or on slippery ground such as ice or black ice, or in or on the surface of a fluid. This also makes it possible to travel on irregular surfaces such as uneven ground or shallows and to navigate on rivers or streams considered unnavigable, or even in poorly known maritime areas.

[0030] In order to limit the bulk of the device according to the invention, a traction accessory is located in its retracted position inside the volume of which the outer face of the tread is the envelope, and is therefore not located next to the wheel or the track, and even less between two wheels or between two tracks.

[0031] An important point is that the deployment and retraction of a traction accessory must be achieved by sliding within all or part of said tread, as this is the condition for the sliding to follow a fixed trajectory within the tread, i.e., without changing the exit angle of the accessory with the outer surface of the tread. This sliding can be linear, curvilinear, or rotary, but advantageously, its direction cannot be changed during its deployment or retraction, because otherwise the tread would have to be thicknessless, or a part of the tread would have to be able to rotate around an axis parallel to the axis of rotation of the traction accessory during its deployment / retraction movement, which is too complicated.

[0032] In one embodiment, the traction accessory is a traction vane of the vehicle by its pressure on a fluid such as mud, water or air, but it can also be an extension of a tire or track allowing it to roll on the ground muddy or snowy, or in certain modes of implementation a crampon or a series of crampons to prevent slipping on black ice or ice.

[0033] It is particularly advantageous for the traction device to include an elastic return means 31 allowing the retraction of a traction accessory when an obstacle prevents its deployment during the cycle. This elastic return prevents damage to the traction accessory when it encounters an obstacle or excessively hard ground.

[0034] When the wheel or track of the invention includes a tire or other equivalent device enabling it to deform elastically when encountering an irregularity in the surface on which it rolls, the restoring force of the elastic restoring means 31 is advantageously less than that of the elastic deformation of the tire or track, so that the elastic restoring means 31 does not disturb the elasticity of the wheel or track.

[0035] An important improvement consists of equipping the traction device with a means for adjusting the elastic resistance of this elastic return, so that an operator or a computer can adjust it by means of a control. This makes it possible, for example, to have a smooth tire wheel to save energy when traveling on a dry paved road, but to deploy traction accessories when necessary.

[0036] The traction device can be equipped with traction accessories of several different kinds, such as traction vanes and crampons.

[0037] A traction accessory can also change its nature depending on the extent of its deployment. For example, a protrusion can be deployed with a small extension, while a larger extension causes cleats to protrude.

[0038] The present invention is particularly suited to wheels with airless tires. These tires most often consist of a central hub and a tread connected by multiple elastomer links that ensure the tire's elastic deformability. In this case, the traction accessories are advantageously positioned between these links when in the retracted position. It is also suitable for airless tracks made according to the same principle of elastomer links ensuring good track deformability, allowing for high-speed operation.

[0039] Without departing from the scope of the present invention, traction accessories can also be arranged in a retracted position not inside the wheel or track of a vehicle, but outside of that element. The essential point is that they can be deployed to move from a so-called retracted position to a so-called deployed position by moving in a direction from the so-called inner face to the so-called outer face, and vice versa. In An advantageous version is that they can be rotated to limit their size when retracted.

[0040] A traction device according to the invention may also be a second wheel or track attached or not to a wheel or track. This second wheel or track according to the invention may be removable, and for example only be installed when necessary, for example when the vehicle is stuck in mud.

[0041] An assembly comprising traction accessories according to the invention can also take the form of a track fixed to the periphery of a wheel, or several wheels, or an existing track.

[0042] The movement of the traction accessory can be arranged so that, when moving forward, it moves backward when transitioning from the deployed to the retracted position, and forward when moving backward. This facilitates its retraction if it encounters an obstacle while moving forward. This requires that the direction of the sliding motion be inclined relative to the vertical line passing through the same point on the tread (not shown).

[0043] The geometry of the traction device is advantageously designed such that the effect of a rotational moment applied to the device by a traction accessory, if it is less than a determined threshold, is not sufficient to make it move from its deployed position to its retracted position.

[0044] Those skilled in the art have many means at their disposal to prevent a traction accessory in the deployed position from moving into the retracted position under the effect of a tangential force applied to the tread, in both directions of rotation known as forward and reverse. - in the case of sliding, the trajectory is perpendicular to the force - in case of rotation, the tangential force does not give rise to a rotational moment applied to the traction accessory because the force exerted on the deployed part of the traction accessory is aligned with its center of rotation.

[0045] The rotation of the traction accessory caused by a force with a tangential component can also cause it to bump against an obstacle which prevents its retraction.

[0046] The designer can also determine the characteristics of an elastic return to be applied to the traction accessories so that a force applied to one of them is less in the direction of rotation said forward than a predetermined threshold, and in said direction of rotation said reverse than a predetermined threshold which may be different.

[0047] A traction accessory may pass through the tread as shown in the figures. To maintain the material continuity and sealing of the tread, or for other reasons, it may also be located inside the tread and deform its outer surface without passing through it, for example by bearing against its inner surface when it passes through the deployed position, or be embedded in This band, in its retracted position, does not cross over the band and moves away from it towards the outside of the traction device in its deployed position. These versions are not shown.

[0048] A traction accessory can have all sorts of possible shapes (not shown), for example, a flat surface parallel to the axis of rotation of the wheel or track, as the case may be, a set of surfaces forming a V, a portion of a sphere, or even a rod or a set of rods, depending on the intended use. In a version particularly suited to vehicles without a steerable wheel, the track or wheel must be able to slip laterally easily. In this case, it is advantageous for the furthest end of the traction accessory to be parallel to the axis of rotation of the wheel or track, as the case may be, which does not preclude the rest of the traction accessory in question from having a different shape.

[0049] The travel of a traction accessory can be greater than that which takes it from the retracted position to the deployed position, both towards the inside of the tread to reach a so-called extreme retraction position, and towards the outside to reach a so-called extreme deployment position.

[0050] The assembly consisting of a traction accessory and its deployment / retraction mechanism can, in one of its possible positions, extend beyond the thickness of the tread to be located partly in a volume whose periphery is the inner face of the tread.

[0051] The extreme retraction position may, for example, correspond to all said traction accessories being placed in a position in which they are not rotationally fixed with the traction device.

[0052] The extreme deployment position can for example cause the cleats of the traction accessory and / or the tread to come out, in addition to the extension of the blades allowing driving on muddy ground.

[0053] The deployment and retraction of traction accessories can be achieved in numerous different ways without departing from the scope of the present invention, by independent mechanical, pneumatic, or hydraulic means, or by magnets or electromechanical means, which may be independent. These means can be coordinated by a single means, but it is simpler to equip the device with a mechanical means for selecting a set of predetermined positions. In both cases, the means for determining a configuration of the traction accessories is hereinafter referred to as a synchronizer.

[0054] This synchronizer is advantageously a purely mechanical mechanism, excluding any use of hydraulic or pneumatic technologies, in order to benefit from the simplicity and reliability of such mechanisms, reduced maintenance and low cost, but this is not mandatory.

[0055] This synchronizer can mechanically connect, directly or indirectly, the vehicle with a plurality of traction accessories. Such synchronizers are shown in Figures 1, 2, 3, 6, 7, 11 and 13.

[0056] Different types of synchronizer are proposed which can produce cyclic movements of said traction accessories.

[0057] A synchronizer may, for example, include a secondary shaft 40 parallel to the axis of rotation of the traction device. This shaft may be offset from this axis of rotation and rotate with the traction device, as shown in Figures 1, 2, and 3. When the wheel is driven by means of a shaft connecting a motor to the wheel, it is difficult to position the synchronizer hub on the axis of rotation of the wheel if this hub does not have a central recess allowing the shaft connecting this motor to the wheel to pass through (or if the wheel hub does not have a central recess allowing the secondary shaft to pass through). In this embodiment, the synchronizer hub is bulkier and may also be more expensive to manufacture, particularly if it incorporates ball bearings. One solution may be to position it on the side of the wheel opposite the vehicle chassis.In a particularly advantageous embodiment, not shown, the motor of a wheel according to the invention is located within the wheel itself. In this case, the wheel no longer has a shaft to connect to the external drive hub, and the synchronizer hub can be located on the wheel's axis of rotation to determine the position of all traction accessories, while also being situated on the side of the wheel connecting it to the vehicle chassis. It is also possible to use a hubless wheel driven by its rim to achieve the same advantage.

[0058] The synchronizer may also include a cam cooperating with a follower or a pusher, for example one or more fixed cams 401 and 402 as shown in Figures 6 and 7. Those skilled in the art may use either concave or convex cores, or assemblies of both types, to modify the position of the traction accessories during the cycle.

[0059] The synchronizer may advantageously deform elastically and / or have flexible parts. This elasticity may also constitute the so-called elastic return mechanism 31 allowing the retraction of said traction accessories when an obstacle opposes their deployment during the cycle.

[0060] In a version advantageous in many cases, not shown, the synchronizer may comprise a cable consisting of a flexible sheath and an inner cable that slides inside the sheath and operates by tension or compression. This allows the transmission of mechanical motion over a certain distance, while adapting to non-straight paths thanks to its flexibility and In particular, it has the advantage, in the case of airless tires, of being compatible with the chosen shape of the connections between the hub and the tread.

[0061] In the case where the synchronizer consists of a mechanical assembly comprising a secondary shaft 40 connected directly or indirectly to traction accessories by rigid or flexible links, it may be necessary to provide a specific device to synchronize the rotation of the secondary shaft 40 with that of the primary shaft 10. Those skilled in the art have many known means to achieve this synchronization.

[0062] A gyroscope or any other known means can be used to determine the position of the device in space in order to determine the position of a traction accessory within the cycle. However, in a simplified version, the synchronizer can be mechanically linked to the vehicle, and the vehicle can be used as a reference point to determine the position of a traction accessory within the cycle. In this latter case, the vehicle therefore comprises the fixed part of the synchronizer, and optionally a means for modifying the configuration of the synchronizer and a means for controlling this modification, which can be operated by a person or by a computer. The person or computer in question can be located on the vehicle or outside of it, using, for example, remote control means, without departing from the scope of the present invention.

[0063] The designer can use many known means to easily maintain the airtightness of an inflated tire, or prevent foreign bodies from passing through the tread.

[0064] An elastic means may be provided so that, when a traction accessory has been placed in its fully retracted, retracted, extended, or fully extended position, it remains in equilibrium. In either of these two cases, the synchronizer or another mechanical means may be used to place a traction accessory in one of these equilibrium positions. An advantage of this solution is that it can maintain all traction accessories in a stable position throughout the rotation of the wheel or the entire cycle of a track, without friction between the traction accessory and the tread. In this case, it is recommended to equip the device with several means for changing the equilibrium position of a traction accessory.

[0065] Fixed magnets or electromagnets can, for example, be used to move or hold traction accessories in the retracted position in the upper part of the tread, and other magnets or electromagnets to move the traction accessories into the deployed position on command. These magnets or electromagnets can be located at unique positions along the cycle. Magnets can be moved to be active or inactive or reversed to have different effects reversed. A single electromagnet may be sufficient to move the traction accessories from the retracted position to the deployed position or vice versa.

[0066] Depending on the synchronizer configuration, the traction accessories may be, for example: - either all in retracted position, - or all in deployed position, - or those which are in one part of the cycle in deployed position, and those which are in another part of the cycle in retracted position.

[0067] Regardless of the type of synchronizer chosen, it is possible to move the traction accessories located at the bottom of the traction device to their deployed position and, conversely, to move those located at the top to their retracted or fully retracted position. This has the advantage of reducing the device's size and, above all, of not offering resistance to the forward movement of a vehicle equipped with a wheel or track according to the invention when it moves on or in water. This distinguishes the device according to the invention from older paddle wheels, the upper part of which could strike waves, thus hindering the boat's progress, and it allows the use of a fully submerged wheel. The device according to the invention thus makes it possible to propel a submarine, a land vehicle, or a boat that becomes a submarine.This also allows the use of wheels according to the invention with existing vehicles undergoing only slight modifications, by preventing the traction accessories from striking the wheel arch in the bodywork. This can be achieved by numerous means available to those skilled in the art, such as a stop fixed to the vehicle chassis preventing the traction accessories from deploying in the upper part of the tread. Such a stop is formed by belts 61 and 62 on the track of [Fig. 13].

[0068] The operation of the synchronizer makes it possible to determine in real time, according to the conditions encountered and the desired driving mode, which part of the cycle the traction accessories are in the deployed position and which part they are in the retracted position, which traction accessories are moved, and what the extent of the deployments considered is.

[0069] When the device according to the invention is a track, the synchronizer can elastically push the lower traction accessories towards their deployed position. Advantageously, it simultaneously and continuously pushes those at the top towards their retracted position. This can be a simple stop, a rail, a cable, or belts 61 and 62 as shown in [Fig. 13].

[0070] The synchronizer can also, as shown in [Fig. 3], position the traction accessories so that their motorized rotation gives rise, during rotation from the wheel to a force directed more downwards, which can be used to pull a vehicle out of the mud, to push a vehicle navigating on water upwards to reduce its drag, or even to make it take off and fly in the air.

[0071] Similarly, the synchronizer can also place the traction accessories in a different position, placing them in a deployed position in their rear part, so that they give rise to a force directed more downwards in the case where their rotation is driven by the movement of the fluid on which or in which they rotate, which can allow the vehicle to be raised above water or mud when towed or propelled by a sail or kite.

[0072] A traction accessory may include a portion of the tread. The traction accessories as a whole may also constitute all or almost all of the tread of the device when all the traction accessories are in the retracted position.

[0073] Traction accessories advantageously have an internal structure made of rigid but flexible materials, and are easily removable so that they can be replaced quickly.

[0074] To allow a large number of traction accessories to deploy simultaneously, the deployment of one of them can cause the deployment of another traction accessory, and its retraction can cause the retraction of yet another traction accessory. Those skilled in the art know many ways to achieve this result, whether the objective is to drive a nearby or distant traction accessory.

[0075] It is advantageous to be able to modify the nature of a traction accessory depending on the extent of its deployment. For example, the deployment of a tire tread pattern can, if more pronounced, cause the lugs of that tread pattern to protrude. More generally, the deployment of a traction accessory can thus cause, during part of this deployment movement, the deployment of another traction accessory of the same traction accessory.

[0076] Wide tires or tracks offer the advantages of good traction, good stability in corners, short braking distances, and ride comfort, but result in higher fuel consumption. It is therefore advantageous that the deployment of a traction accessory can increase or decrease the tread area, that is, the area actually in contact with the ground when the traction device is traveling on a flat, hard surface.

[0077] In one of its configurations, known as energy saving, the tread area may be less than half its value in another configuration, known as maximum efficiency.

[0078] Figure 10 shows a means of varying the outer face of the tread, illustrating three different configurations obtained by simply changing the distance of the traction accessories to the wheel's axis of rotation, which shows that the same tire can be used in many different applications.

[0079] This method of implementation can be combined with others, some of the traction accessories also being able to deploy further to become paddles, or include crampons that deploy from a certain deployment of the traction accessory that includes them.

[0080] In a simplified embodiment, a small deployment of the traction accessories simultaneously affects all traction accessories of the device, while a larger displacement affects only some of them. This is easily achieved with a convex cam configuration similar to that described in Figures 6 and 7.

[0081] The optimal configuration can be controlled by a user, but also in real time by a computer that takes into account the vehicle's speed and trajectory, its load, and the state of the medium on or in which it is moving. The traction device then advantageously includes sensors to evaluate these parameters.

[0082] In the so-called energy saving configuration, the tread surface may not have a positive or negative tread pattern (also called a groove) exceeding 0.5% of the total height of the traction device.

[0083] In this so-called energy-saving configuration, the tread advantageously comprises one or more continuous or discontinuous rings, each with a width less than 20% of the tread.

[0084] The possibility of deployment and / or retraction of a traction accessory can be limited by friction, for example by modifying the structure of the contact surfaces during sliding or rotating movement, when subjected to a significant torque resulting from resistance to the vehicle's forward motion. Ball or needle bearings, or equivalent devices, can also be used.

[0085] A synchronizer configuration can be provided in which the traction accessories are stored near the axis of rotation of the wheel hub 10 in the hyper-retracted position. In this case, they can remain stationary relative to the rest of the wheel throughout the wheel's rotation. This is one way of eliminating any friction caused by the passage of traction accessories during wheel rotation.

[0086] The synchronizer can advantageously be constructed of a material or have an architecture that allows it to undergo elastic deformation. This has the effect that, in the case where friction due to the passage of a traction accessory from one position If another exceeds a certain threshold, it can deform to cease producing the expected effect, and therefore refrain from causing deterioration of the traction accessory in question or of the synchronizer.

[0087] Without departing from the scope of the invention, a wheel may be fitted with one or more circular flanges allowing it to roll on the ground. The same applies to a track that may be fitted with an auxiliary track supporting part or most of the weight of the vehicle.

[0088] In a particular embodiment, the wheels or tracks constituting the traction device according to the invention may be less dense than water in order to contribute to the buoyancy of the vehicle when it travels on water. They may even provide its buoyancy on their own.

[0089] Wheels or wheel parts located between traction accessories, inflated at low pressure or made of very flexible materials, can ensure comfortable rolling and effective traction on uneven ground. This also applies to tracks or track links.

[0090] Figure 5 illustrates an implementation particularly suited to this case. The left wheel has controls for deploying / retracting the blades (51 for blade 21) while the right one does not, the blades being either each positioned according to the resistance of the ground or according to an autonomous deployment / retraction device.

[0091] The advantage provided by the fact that the housings 210 and following of the traction accessories are fixed only to the tread of the wheel IA is important, because in this case these housings can be rigid and allow deployment with low friction of the traction accessories.

[0092] A mechanical means (not shown) may be provided to automatically deploy certain traction accessories when the force exerted by the traction device on the vehicle chassis is less than a predetermined value. This allows, for example, the accessories to automatically deploy when the vehicle is floating on water, since the force exerted by the traction device on the vehicle chassis is then reduced.

[0093] In a particular version not shown, the traction accessories are not permanently linked to the wheel or track. A so-called selector device has the effect of - either in a first configuration of moving the traction accessories into a retracted position, and then they stack on top of each other, without being driven by the wheel or the track, - or, in a second configuration, to move them into a deployed position, in which they are driven by the wheel or track, moving away from the tangent plane at the periphery of the wheel or track, as applicable. An additional device allows the traction accessories that pass towards the top of the wheel or track to move into a retracted position.

[0094] Those skilled in the art know how to equip the traction device with means to prevent foreign bodies from slipping between the traction accessories and the fixed parts of the traction device. They can provide clearance between the faces of the traction accessories and the fixed parts that guide their extension / retraction, and incorporate elastic parts to prevent these foreign bodies from damaging the device or the traction accessories, or from blocking extension / retraction, while also driving these foreign bodies in a preferred direction to allow their expulsion either towards the periphery of the traction device or in the opposite direction. These means are numerous, known to those skilled in the art, and are not shown here.

[0095] The invention also includes a vehicle equipped with a traction device like those described above. Advantageously, such a vehicle comprises the part of the synchronizer that does not rotate with the traction device, and / or a means for adjusting the elastic resistance of the elastic return 31, and / or a means for modifying the configuration of the synchronizer, and / or a means for controlling these two adjustment or modification means.

[0096] A very simple version of the present invention is illustrated in [Fig.12]. It is a traction device according to the invention which comprises only one wheel or track and a means of connection between this wheel or track and a towed or pushed element, which may be a human being or any vehicle.

[0097] This device can be used as a replacement for conventional outboard motors. It is a self-contained wheel according to the invention, which can house its own motor and is advantageously watertight. The battery can also be integrated into the wheel or placed in the vehicle towed or pushed by this wheel. A simple oarlock placed at the bow of the boat is therefore sufficient to equip a vehicle with the device.

[0098] Such an autonomous wheel also allows a person to pull themselves along in water skiing or with any inflatable mattress or boat, but they can also, by determining the position in which the blades come out, swim either on the surface or even underwater.

[0099] The direction is determined by tilting the handlebar 301 to one side or the other. Controls 302 and 303 allow the wheel's rotation speed and the blade configuration to be controlled. For safety, as soon as the handles are released, the motor stops and the assembly floats.

[0100] Such a self-contained wheel can also be used as a personal ski lift to ascend snowy slopes. The wheel can then be narrower so that it can be easily packed into a backpack during the descent, and the handlebars can be replaced by a simple rope, optionally with a harness. It's also a way to pull a cart or a sled, and to get a car out of the mud.

[0101] The invention also relates to a land or water vehicle equipped with a single wheel or track according to the invention. In an improved version, it can be equipped with the stabilization means used by vehicles known as "gyrowheels," which include a self-balancing system based on the principle of the gyroscopic motor, sensors that continuously measure the wheel's tilt and speed, and a motherboard that processes the sensor information and controls the motor. The user then controls the vehicle by changing its tilt, leaning forward to move forward and accelerate, straightening up or leaning slightly backward to slow down or stop, and applying more or less pressure to footrests to steer the vehicle.

[0102] One or more single-wheeled vehicles according to the invention can also serve as tug(s) for a boat and be remotely controlled. These vehicles can be very lightweight if they are electric and do not include their power supply battery. A significant advantage is that they eliminate the need for a fixed engine on sailboats of all sizes, and can also be used as auxiliary engines for all types of watercraft.

[0103] In a particularly advantageous embodiment illustrated by [Fig. 8], the vehicle is equipped with an obstacle-crossing aid 70 connected directly or indirectly to the vehicle chassis by a mechanical linkage such that it lifts the vehicle when encountering an obstacle by moving from a retracted position, in which it is not in contact with the solid or liquid support on which the vehicle rests, to a deployed position in which it supports the vehicle with the obstacle in question. This obstacle may be solid, a wave, or an overpressure of the fluid on which the vehicle is traveling. All obstacle-crossing aids described in the applicant's patent application FR3048404A3 of September 8, 2017, may be used without departing from the scope of the present invention.

[0104] The invention also includes the means of generating electricity, consisting of a wheel or track according to the invention, propelled by the current of a fluid or gas. This makes it possible, for example, to recharge the batteries of a boat or submarine when it is stationary. For instance, boats and submarines could be built that never need to be recharged because they automatically stop and drop anchor as soon as their electrical charge is too low, and then resume their journey when their electrical charge is sufficient. Such boats could have other means of generating electricity (holomotive, wind, or solar, for example) and be able to come ashore. to discharge this electricity into the grid, without having to install cables between their electricity production location and the ground.

[0105] The invention can also be used to rotate the wheels of an aircraft before landing by utilizing the airflow generated by its speed, so that they spin fast enough before touching down, thus saving the rubber usually lost during landing. It should be noted that, unlike other methods considered in the prior art, this one is lightweight and does not increase the size of the landing gear. In particular, the blades can be very thin and positioned between the cords forming the tire carcass, which are especially important during braking.

[0106] The invention also includes the method of maneuvering a vehicle equipped with a traction device according to the invention, by a human operator or a computer, the maneuvering of the vehicle comprising a step of modifying the configuration of the synchronizer by a control means for modifying the configuration and / or a step of adjusting the elastic resistance of the elastic return 31 by the control means for adjusting this resistance. Applications

[0107] The present invention applies to all land vehicles, from bicycles to trucks and including passenger vehicles, to save energy and allow automatic adaptation to traffic conditions.

[0108] The most astonishing applications of the present invention are land vehicles that can travel on roads as well as on uneven or muddy ground and sail on water or in certain versions take off and land vertically and fly in all directions, as well as a large or small boat, a submarine navigating in the water or rolling on the bottom, or an aircraft, all these vehicles being able to land on a beach and cross shallows without damage.

[0109] These vehicles can be used for leisure or work, rescue, public works but also for military combat.

[0110] They can be piloted by humans, whether passengers or not, using remote control means, or by computers.

[0111] Another important benefit is to make many rivers navigable which are not currently so.

[0112] A particular application is the propulsion of persons on snow or on the surface of water, as well as in water, these persons being able or not to be equipped with an accessory such as skis or a surfboard.

[0113] All land, water or air vehicles are concerned, including high-speed vehicles where the main objective is to save energy and adapt the tread structure in real time according to the conditions encountered and driving style.

[0114] The main vehicles likely to benefit from the version of the invention in which some blades are deployed and others are not are as follows: - fishing boats on rivers, ponds, or marshes, - the tenders of pleasure boats, - leisure barges and canal boats, - military ground drones, certain tanks, artillery or missile launchers, and more generally military equipment that must be able to be transported autonomously from one point to another, - Public works or agricultural vehicles that must cross wet, muddy or snowy areas, - and remote-controlled vehicles for recreational use such as toys.

Claims

[Claim 1] Demands Vehicle traction device such as a wheel (IA) or a track (IB) comprising - a tread, comprising an outer face which is in direct contact with the road when said traction device travels on a flat road, and an inner face which is separated from said outer surface by the thickness of said tread, which may or may in particular include a ground contact material and a framework commonly called the carcass which ensures its strength and resistance to load, - a plurality of so-called traction accessory elements (21, 22 and following), - and a so-called deployment / retraction mechanism allowing a traction accessory to deploy by sliding within all or part of the thickness of the tread, the sliding taking place along a fixed path in the tread, to move from a so-called retracted position to a so-called deployed position by moving in a direction from the inner face to the outer face, and vice versa, - a traction accessory being located in its retracted position within the volume of which said outer face of said tread is the geometric envelope, characterized in that - a traction accessory, in its deployed position, forms an outward projection of said tread towards the outside of said external surface, and contributes to the vehicle's traction by its pressure on a fluid or granular medium, - and that all of said traction accessories can be simultaneously in the retracted position, It being specified that above and below, "to deploy and to retract" means movements of a traction accessory going respectively in the direction from the retracted position to the deployed position and in the opposite direction.

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