IL103441A - Amphibious land vehicle - Google Patents

Description

^nt!D* >D>£H3N DI >ίθ AMPHIBIOUS LAND VEHICLE Amphibious Off-Road Vehicle as a Utility and Working Apparatus The invention relates to an amphibious off-road vehicle as a utility and working apparatus, comprising a carriage on which at least four wheels are suspended through wheel suspensions with pairs of the wheels opposing each other, wherein the wheels of at least one of the wheel pairs are power-driven wheels .

On the one hand, working projects in humid biotopes, swampy vegetation areas, bank reeds, nature reserved straw and salt meadows, and other natural ground require the surfaces to be hurt as slightly as possible, on the other hand such projects also necessitate frictional soil engagement to provide traction for the attached cultivating and accessory units.

On bare sediments, in pond facilities for breeding fish, emptied water storage reservoirs, settling fields, washing basins, damp areas containing noxious matters and remanent pollution, clearing sinks and mud pits, on aqueous excavated material and the like, the upper surface dries in an unreliable manner - often only after long drying periods and weather-dependent waiting times -, as these soil materials lack any inner structure and are over-saturated with moisture; where the bottom of such grounds is deep enough, walking or driving on such surfaces entails the latent risk of getting stuck or stalled and subsequently submerged in the mud.

In the art of vehicles, the term amphibious vehicle applies to apparatus mobile both in water and on land. From US patent no. 3,941,074, for example, it is known to provide a floatable bus by arranging the wheel suspensions on the exterior of the wheels, the wheels being pivotable from their vertical position to a horizontal position in which they serve as buoyancy aids for the bus body depending below the horizontal wheels and contribute to its self-buoyancy. This bus is thus capable of driving off the road into a lake in which as soon as the bus body floats, the wheels are pivoted to the horizontal position and their sides facing each other in the vertical position then face downwards in the horizontal position; the wheels, along with planks arranged thereabove, form a kind of rail for the bus .

From DE-AN A 18533 XI/65a2, it is known for a mud-flat vehicle to design the vehicle body floatable, incline the bowl-shaped wheels at a positive camber, form the underside of the wheels as flattened hemispheres, and render the level of the wheels adjustable, thereby allowing the wheels to compensate for uneven lateral ground in order to avoid skidding when travelling on ooze grounds which as such bear but yield laterally in their upper layers .

However, such amphibious vehicles are not at the same time suitable for conglomerates of water and soil such as bog, mud, ooze, coarse clay and other ground mires. On the contrary, as long as in the usual amphibious vehicles the buoyancy arises from immobile components - sealed tanks, watertight coaches, casings for working devices, accessory floats, boat parts, hulls -, the risk of getting stuck in soft terrain carrying no water layer, or only a thin one, while having deep ground sediments in the lower layers, is by far greater than with normal driving equipment. For if the overcharged ground material no longer bears and yields, the driving members dig in until a larger overall bearing area and better pressure distribution are obtained. The underside of the apparatus then seats on the ground and thus gets fractionally stuck. In this belly-grounded position, the apparatus is finally immobilized in self-dug wheel hollows or track ditches, without achieving any further self-propulsion. If the ground yield exceeds a certain limit, the sinking process begins after some waiting period.

Beside the principles of conventional vehicle technology using wheeled or tracked carriages, there exist other solutions of carriage implementation for driving and working on grounds whose load-capacity is below normal. DE-PS 973 586, for example, discloses - in accordance with the preamble of claim 1 - a vehicle for driving on ooze and mud grounds, in which the wheels of an apparatus and working platform are formed as inclined hollow truncated cone members drivable through vertical drive shafts and rotatable by means of rotatable pressure rollers without changing the angle of inclination with respect to the ground, in order to enable the vehicle to be steered in a defined manner. Along the cone envelopes, the hollow cones are provided with rib-like grippers. It is not demanded for that the vehicle be made floatable or diminished in size for the transport.

Under all conventional preparations and specializations, the known vehicles driving on ground have not succeeded in extending their working range reliably on extremely weak soft grounds having liquid lower ground layers , in carrying out cultivating measures on the vegetation existent there while preserving natural species and saving the surfaces, and in getting along on undried soft-material surfaces without getting deeply immersed and without driving members digging therein.

Starting from the prior art according to the preamble of claim 1, the invention solves the problem of providing an amphibious off-road vehicle as a utility and working apparatus of light construction, which vehicle can drive on grounds of varying consistency, e.g. on roads or mud grounds, without substantially destroying the vegetation on soft grounds, which vehicle is further capable of floating, can easily achieve the transition from hard to soft grounds and can be quickly loaded and transported without having to rebuild the carriage.

According to the invention, this is achieved by the features that a) the wheels are drivably pivotable about an axis extending parallel to the travelling direction of the carriage, the wheels being pivotable from a substantially vertical position to a substantially horizontal. position, b) the driven wheels are also drivable in all positions between the vertical position and the horizontal position, c) the wheel suspensions are arranged on the exterior of the wheels such that the interior sides of the wheels facing each other in the vertical position face downwards in the horizontal position, d) the wheels are formed as buoyancy bodies and their interior sides are domed substantially lenticularly such that in the horizontal position the wheels constitute the only buoyancy bodies bearing the entire weight of the vehicle already at a small depth of immersion.

Therefore, according to the invention, when driving on soft and muddy grounds , a rotating-gliding motion is selected for the lenticularly hollow wheels in an almost horizontal position thereof, at least the interior sides of the wheels being continually closed and arranged at a distance below the carriage of the apparatus when in the horizontal position.

These disk-like wheel members having an edgeless convex transition towards their outer periphery can generate a lateral component with respect to the travelling ground when they, for driving on soft ground, are tilted by only a few angular degrees from the completely horizontal position. The bearing angle with respect to the ground may be altered both during the rotating-gliding motion and at standstill. The inclination range of the wheels is wide enough to enable a camber of the wheels to be possibly positive or preferably negative in their initial vertical position. Hence, the vehicle can also travel on ground like a normal wheeled vehicle. In addition, the vehicle of the invention assumes a minimal breadth when its wheels are set at least approximately vertically as compared to the wheels being completely spread out, such minimal breadth rendering the apparatus suitable not only for driving in streets and on roads but also for loading and transporting it without having to dismantle it.

Apart from its disk-shaped hollow wheels, the amphibious working and utility apparatus of the invention does not comprise any other buoyancy means such as sealed tanks, hulls or the like. The interior sides of the wheels face downwards in the horizontal position and are arranged in this position at a distance below the carriage.

The amphibious working and utility apparatus of the invention may be designed and modified in various versions depending on the circumstances and requirements of the application; it may be manned and controlled by the driver, unmanned under remote control, automobile and self-propelled, automobile and having a long-distance power supply, propelled by external force, or operated in mixed variants thereof .

The totally closed interior sides of the wheels are formed crowned without any edges at least in the area of their periphery, whereas they may be left open at the wheel centers, possibly in a more or less concave or different manner.

Preferably, the interior sides of the wheels are formed continually lenticularly.

Although the interior sides of the wheels may be profiled with lugs or ribs, traction profiles may impair the utilization of other advantages such as the cleaning process afforded by mechanical stripping during rotation and the damage-free rotating-gliding movement of the wheels on vulnerable vegetations. Therefore, the interior sides of the wheels are preferably formed as continually smooth surfaces .

Further, although the interior sides of the wheels may be formed by rigid walls, they are preferably formed as envelopes which are flexibly bulgeable by internal pressure. By this feature, the interior side of the wheel maintains ground contact in all positions, or at all angles, through a glider envelope forming in the horizontal wheel position a cushion downwards and radially; thanks to its lenticular underside, the glider envelope can be raised from the entirely horizontal position to the vertical rolling position without tilting at any wheel edge, and can be loaded and operated in all intermediate inclined positions without any particular locking of the angular positions. Preferably, the wheels include several concentric annular chambers which are inflatable in order to bulge the envelopes. Through variable pressurization of the annular chambers, the flattening of the envelopes as a whole, or their shape, peripheral position, or characteristic may be adjusted and varied even during driving and can thus be adapted to different ground qualities and different wheel positions. The flat-cushion envelope itself preferably consists of friction resistant material avoiding wet gliding adhesion, which material can be reinforced without perforations while ensuring a stable diameter and preserving the flexing softness of the envelope. Besides, the envelope may be designed as an-exchangeable wear part and mounted in an easily detachable manner for this purpose.

If the envelopes are exchangeable, it is possible not only to replace the gliding surfaces of the wheels after wear, but also to substitute particular profiled envelopes for the unprofiled glider envelopes when driving on grounds and materials which have neither adhesive nor vulnerable surfaces while requiring great traction.

The amphibious utility and working apparatus of the invention may also be designed steerable, for example by providing an articulated carriage having joints between the wheel pairs.

However, since in this case the cramping of the wheels has to be taken into account for the axial length of the vehicle, it is preferred to achieve the steering of the vehicle by different rotational speeds of the wheels on both sides of the vehicle. Hence, the drive of the driven wheels is preferably reversible and the rotational speed can be controlled separately for each side of the vehicle, thus further allowing the vehicle to be driven forwards and backwards .

Further, in order to obtain optimal propulsion characteristics, preferably all wheels of the vehicle according to the invention are driven wheels . Further it is preferred to design the pivoting drive mechanism of the wheel suspensions to be separately adjustable for each side of the vehicle instead of being only adjustable for both sides of the vehicle in common; in a further embodiment of the invention, each of the wheel suspensions may be drivably pivotable and controlled along with the other ones or individually.

For the amphibious off-road vehicle of the invention, four, six or eight of the flat-cushion disk wheels described above are assembled to a carriage, wherein wheels in pairs oppose each other. Accordingly, the flat position of the wheels already provides a wide ground contact of the carriage comprising large individual bearing areas which additionally exhibit a softly pressing, yielding nature. Edge shearing is avoided due to the bulged elastic peripheral transitions .

The carriage properties of the apparatus, which are thus favourable already from a static, ground-mechanic point of view, are supplemented - in a particularly preferred embodiment of the invention - by the advantageous effects of an additional dynamic buoyancy aid implemented by a respective fan arranged at the transverse middle of the carriage between two adjacent wheel pairs, each fan being directed downwards between the wheel pairs . The fans aire preferably constituted by ducted fans or impellers, and their blowing performance is preferably controllable.

If a fan is embodied by an impeller, the compressed air generated by the fan and directed downwards may be adapted to varying needs by varying the rotational speed or by adjusting the blades of the rotor and stator. In a plan view, a respective fan is disposed centrally above the rhomboid free space between mutually adjacent wheel pairs. Hence, the dynamic stream of compressed air is not blown onto the wheels lying flat, but will act below these. Further favourable shields and air guides can be provided, as well as a cover or partial hood for the gliding disk wheels, without however intending to create a hovercraft.

The completely flat position of the gliding disk wheels on the ground is only necessary when the specific ground pressure values have to be as low as possible, and when by displacement buoyancy the wheels have to be prevented from getting submersed below the surface of over-wet slippery grounds. As a propulsion aid in this driving state as well as in the floating state, an additional propeller may be provided, for example. Where this extreme position is not absolutely necessary, a mixed driving mode can be established between the completely rotating-gliding travel and an incipient half-rolling travel; the driving mode position can thus be adapted to improved ground conditions . To this end, the flat-cushion disk wheels are set to a somewhat more inclined angular position.

When the disk wheels are raised together to greater angles of inclination, the stream of air departing from the middle of the apparatus flows into the flat wedgelike free space or into the contact region between the interior sides of the wheels and the ground; there, this sweeping inrush of air acts to avoid a separating vacuum while cooling the frictional surfaces of the wheels when driving on relatively dry ground, and tends as a whole to lift the load. While in this process - when the wheels begin to back out and rise from the ground - the direct-contact, pressure-distributing surfaces of the interior sides of the wheels diminish, they are in return replaced by the subsequent increase in aerostatic bearing area.

Accordingly, if the blowing performance of the fan is further increased, the wheels may be also set to a steeper position without having to fear an immediate immersion and sinking of the apparatus . Thus , the driving mode can be adapted not only to the softness of the ground, but also to the frictional properties of the ground surface. The provision of air pressure into the inner space and aerodynamic air supply under the wheels serves the further purpose of providing a lifting aid in the fully spread position of the carriage.

The invention will be described on the basis of an advantageous embodiment illustrated in the drawings . In the drawings , Fig. 1 is a perspective view of an amphibious utility and working apparatus according to the invention, the wheels being fully spread out, however without any superstructures which can be mounted on the carriage, Fig. 2 is a perspective view of the apparatus of Fig. 1, the wheels being raised to the rolling position, and Fig. 3 is a perspective view, in a diagonal section, of an embodiment of the wheels of the apparatus shown in Figs . 1 and 2.

The amphibious off-road utility and working apparatus shown is manufactured as a light construction and comprises six wheels 2 arranged in pairs of wheels opposing each other. The wheel suspensions 3 engage the. wheels 2 on-the exterior sides thereof and are pivotable upwards and downwards about a pivot axis 5 which is arranged along the longitudinal sides of the carriage 1 and is displaced by a distance from the centers of the wheels towards the carriage 1; the wheel suspensions 3 are pivotable individually or together under control of pivot cylinders 11. By this arrangement, the position of the wheels 2 can be varied from an initial position shown in Fig. 2, where the wheels 2 are at an angle of 45° with respect to the ground at a negative camber, to a position shown in Fig. 1, where the interior sides 4 of the wheels 2 face downwards while lying horizontally, and back again to the initial position.

In the exemplary embodiment, all six wheels 2 are implemented as driven wheels . Drive is provided separately for each side of the vehicle by motors 9, cooled by fans 10, through gears 14 pivoting together with the wheels 2, and through toothed belts (not shown) such that the wheels can be driven in each of their positions .

In the transverse middle of the carriage, two fans 13 are arranged embodied by impellers having adjustable guide vanes and rotating blades and a vertical axis; each fan 13 is disposed between mutually adjacent pairs of wheels such that streams of compressed air can be generated and directed downwards to the ground between the wheel pairs; the wheels 2 and the ground cooperate to make the compressed air stream onto the inclined interior sides 4 of the wheels 2. The interior sides 4 of the wheels 2 are constituted by surfaces which are smooth up to the wheel centers and extend in the form of discus-like disk surfaces having a circumferential rim which is rounded towards the wheel periphery without any edge transition.

As can be seen from Fig. 3, the wheels 2 are formed hollow, and on the interior sides 4, they comprise wear resistant glider envelopes 6 wrapped around the wheel peripheries towards the exterior of the wheels ; each glider envelope 6 is clamped - in an easily replaceable manner - between an exterior wheel disk 15 engaged by the wheel suspension 3, and the wheel body. The wheel body is formed by an intermediate wall 16 whose side facing the interior wheel side 4 supports two separately inflatable annular chambers 7, 8 taking the form of concentric tubes . The outer annular chamber 7 limits the circumferential part of the envelope 6 towards the exterior of the wheel, whereas the inner annular chamber 8 forms the adjoining part of the envelope 6.

Depending on the embodiments, the advantages achievable by the invention reside in particular in that * a more favourable driving motion providing flat rotation becomes applicable for travelling on extremely soft ground, instead of the vertical rolling movement (such as with wheels rolling on their outer periphery, or with chain tracks); * this is achieved by gliding-rotating, flat-cushion disk wheels 2 assembled in pairs to form a group of four, six or eight wheels, of which not only short peripheral parts bear - as in other wheel carriages, for example - but which use almost their entire circular area for transmitting pressure to the ground ; * floatability of the apparatus arises directly from the actively moved wheels 2, and this floatability is attained by the wheels without any deep immersion displacement; thus, when driving in mud, the carriage immediately develops its broadly bearing buoyancy effect on the surface (or needs to get immersed only a few centimeters for obtaining this effect); hence, both different bearing principles - ground contact, on the one hand, and displacement buoyancy without considerable depth of immersion, on the other hand - can change into each other or act in common; * in addition to these effects preventing immersion by the disk-like flat shape of the wheels 2, a third component can be added in the form of blown air utilizing even the hollow spaces - open towards the ground - of the centered frame structure of carriage 1 whose top side may be closed; * this aerostatic auxiliary action of area increase reduces the bearing pressure when the rotational speed of the impeller is considerably raised and its blades are adjusted; an additional aerodynamic air-sweeping effect arises rushing below the wheels 2 formed as disk wheels and resulting in a wedging action; the air stream cools the disk-like wheels 2 when driving on dry ground, avoids an incipient separating vacuum when driving on pastily soft damp ground, and further acts to lift the weight by rushing under the wheel disk when the latter is inclined at a small angle; in this process, the angular position of the wheels 2 can be controlled such that the wheels 2 still produce sufficient propulsion at their outer , rims although their rotating surfaces are swept by air; moreover, the internal pressure may be lowered in the inflatable annular chambers 7, 8 of the disk envelope 6 - in particular in the supporting annular chamber 8 disposed closer to the center of rotation - in order to establish a concave hollow of the cushion-disk envelope 6 which acts to retain the sweeping air in the hollow or to delay its outflow therefrom; * the flat-cushion wheels 2 can be raised from their flat position while being operable in each inclined intermediate position almost up to the vertical position so that the apparatus need not exclusively remain in its spread-out travelling configuration; rather, the utility and working apparatus of the invention can be easily brought to its road-running mode by automatically adjusting the angular position of the wheels 2 to their steepest inclined position, thus also enabling the apparatus to drive by itself to remote terrains difficult to reach, on hard roads, over narrow bridges , dike summits , through bottlenecks , entries etc . ; at the same time, the apparatus can be quickly loaded for transport without problems and transferred while meeting the normal widths prescribed for road vehicles; and all this can be accomplished by a single operator; * starting from the arbitrarily variable angular position of the wheels 2, for instance one wheel row may be raised and run in a wheel-like manner, while the wheels 2 on the other longitudinal side of the vehicle may be operated in a flat position, which can be crucial for applications requiring asymmetric travel along ditches, for working on embankments or ground basin edges; as the vehicle can travel with its wheels positioned differently on both sides and since the wheels 2 can be inclined individually, also T-mouths of water ditches or front-end crossovers can be managed by pivoting pairs of the wheels 2 downwards or upwards (for entry on steep rims in arrayed cassette basins, on bank rims bordered with concrete or covered with foils and the like); * due to the described angular inclination of the wheels 2, the travelling mode of the vehicle can be adapted to the ground softness but additionally also to the respective current coefficient of surface friction; the flat gliding rotation of the propulsion members is advantageous for damp soft surfaces and can be steepened by a small angular inclination such as to already establish an incipient addition of the rolling travel component which immediately acts to significantly reduce the friction under dryer driving circumstances; this effect may be additionally enhanced by increasing the pressure in the inner annular wheel chamber 8 arranged closer to the wheel center; due to its resultant increased bulging, the cushion envelope 6 can rotate much easier even when kept in its flat position, and also facilitates the inrush of air far below the disk surfaces of the wheels 2 under dryer, and thus usually harder, driving circumstances and ground conditions, without having to further incline the prophylactically flat safety and float position of the wheels 2; in total, a balance and variation of the driving conditions is possible by controlling and readjusting - in addition to the propulsion forces - the bearing angle of the wheel disks, the internal pressure and configuration of the envelopes, thus the frictional characteristics, the flattening of the cushion, the blowing of compressed air below the vehicle, and the air sweeping effects; * the annular chambers 7, 8 of the wheels 2 bear pressure and also support oblique forces and may produce changes in the bulging form of the interior sides of the wheels such that the desired flattening of the envelope 6 and its partial impression resistance can be controlled; these changes in internal pressure may be performed at standstill as well as during travelling; these softness variation of the envelope may be separately adjusted and controlled in inner or peripheral parts, respectively, in order to fill more fully the circumferential rim of the wheel 2, for example for a rolling travel of longer duration, for overcoming edges or when the apparatus is loaded for transport; * the glider envelopes 6 are relatively easy to replace, which process does not even require a jack for the necessary lifting of the individual wheels 2; * under the circumstances of wet soil, the continuous separation of the disk wheel surfaces from the soil is more favourable in the flat rotating mode than in the vertical surface separation mode arising from wide wheels or chain tracks ; * when the working and utility apparatus is supported by pressure means, the overpressure applied between the bearing disk-cushion surface and the ground facilitates the separation process at the moment of incipient breaking up of the contact; * after the supporting phase, the soft envelope rims re-expand their bulges and change their form and, thus, automatically clean themselves partially during rotation, while adherent soil is stripped off by the transverse gliding motion of the supporting surfaces; * the dynamic sweeping air stream blows away the adherent fluid soil components in a peeling manner.

Claims (12)

Claims

1. An amphibious off-road vehicle as a utility and working apparatus, comprising a carriage (1) on which at least four wheels (2) are suspended through wheel suspensions (3) with pairs of the wheels opposing each other, wherein the wheels (2) of at least one of the wheel pairs are power-driven wheels, characterised in that a) the wheels (2) are driyably pivotable about an axis (5) extending parallel to the travelling direction of the carriage (1), the wheels (2) being pivotable from a substantially vertical position to a substantially horizontal position, b) the driven wheels (2) are also drivable in all positions between the vertical position and the horizontal position, c) the wheel suspensions (3) are arranged on the exterior of the wheels (2) such that the interior sides (4) of the wheels (2) facing each other in the vertical position face downwards in the horizontal position, d) the wheels (2) are formed as buoyancy bodies and their, interior sides (4) are domed substantially lenticularly such, that in the horizontal position the wheels (2) constitute the only buoyancy bodies bearing the entire weight of the vehicle already at a small depth of immersion.

2. The vehicle according to claim 1, characterised in that the wheels (2) in their substantially vertical position are inclined at a negative camber.

3. The vehicle according to claim 1 or 2, characterised in that the interior sides (4) of the wheels (2) are formed as smooth faces .

4. The vehicle according to any of claims 1 to 3, characterised in that the interior sides (4) of the wheels (2) are formed by flexible bulgeable envelopes (6), and several concentric inflatable annular chambers (7, 8) are arranged within the wheels (2) for bulging the envelopes (6).

5. The vehicle according to claim 4, characterised in that the envelopes (6) are mounted in an easily detachable manner.

6. The vehicle according to any of claims 1 to 5 , characterised in that "the"drive ¾f"the'driveh^heei's-^is reversible, and the rotational speed is separately controllable for each side of the vehicle.

7. The vehicle according to any of claims 1 to 6 , characterised in that all wheels (2) are driven wheels.

8. The vehicle according to any of claims 1 to 7 , characterised in that the pivot angle of the pivot drive (11) for the wheel suspensions (3) is separately adjustable for each side of the vehicle .

9. The vehicle according to any of claims 1 to 8, characterised in that each of the wheel suspensions (3) is drivably pivotable under individual control.

10. The vehicle according to any of claims 1 to 9, characterised in that three wheel pairs are provided.

11. The vehicle according to any of claims 1 to 10, characterised in that a respective fan (13) is arranged at the transverse middle of the carriage (1) between two adjacent wheel pairs, each fan (13) being directed downwards between the wheel pairs .

12. The vehicle according to claim 11, characterised in that the blowing performance of the fan (13) is controllable.