Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60F—VEHICLES FOR USE BOTH ON RAIL AND ON ROAD; AMPHIBIOUS OR LIKE VEHICLES; CONVERTIBLE VEHICLES
  • B60F3/00—Amphibious vehicles, i.e. vehicles capable of travelling both on land and on water; Land vehicles capable of travelling under water
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60F—VEHICLES FOR USE BOTH ON RAIL AND ON ROAD; AMPHIBIOUS OR LIKE VEHICLES; CONVERTIBLE VEHICLES
  • B60F2301/00—Retractable wheels
  • B60F2301/04—Retractable wheels pivotally

Definitions

• the present invention broadly consists in an amphibious catamaran comprising: two spaced apart hulls; a framework supporting the hulls;
• height adjustment means enabling, in use, one of the sub-frames to be
• wheels stably support the catamaran for travel on land, with the hulls clear of the land, and a position where its associated land wheels are raised upwardly above the bottoms of the hulls; drive means for land propulsion coacting with one or more of said land wheels; steering means for steering the craft on water and on land; and an input station for any person who is to operate the craft on water or on land, or for receiving remote signals to control the operation in use, or both purposes.
• hulls whether they be rigid or not, are securely fixed to a framework.
• the forces exerted by water on hulls can be appreciable and this invention eliminates the need for relative movement between the hulls.
• some other constructions attempting to provide an amphibious craft pivot the hulls about their framework (so that the land wheels can be rotationally fixed to the framework).
• one or more hydraulic pumps also form part of the land and water steering means which also includes rams or hydraulic motors and they also form part of the height control means via rams controlling the movement of the sub-frames.
• the hydraulic motors should be reliable in service as water ingress is impeded by internal oil pressure and they are mostly out of the water. There might also be a favourable automatic distribution of power to the motors exerting the greatest effort if they are hydraulically in series.
• the hulls are preferably wholly or partly non-rigid and preferably wholly or partly inflatable as that has a number of advantages.
• Non-rigid hulls partly absorb forces from the water thus reducing the structural strength needed for the framework and are less prone to being damaged or causing damage or injury.
• the turbo-charger of the diesel motor is preferably used to enable rapid inflation and deflation of the hulls.
• At least the front land wheels would preferably be steered. It is actually preferred to oppositely steer both front and rear land wheels to gain an improved turning circle. Also crab-steering is preferably provided.
• the front and rear sub-frames carry the land wheels at their extremities and are arranged to give leading and trailing arm suspension respectively.
• the extremities can preferably be swung through appreciable arcs, it being preferable to take them totally out of the water to maximise on-water performance.
• the hulls At their maximum lowering to elevate the hulls a maximum height, the hulls might preferably be totally out of the water while the land wheels might still be wholly or partially submerged. This yields improved traction for beaching the craft and a reduced turning circle as the wheelbase is reduced. An intermediate position would suit safer on-road travel.
• “land” when used in this specification includes seabed or any submerged land or any other reasonably solid surface such as a carrier ship loading ramp. Also the expression “land wheel” is intended to include both conventional
• Fig. 1 shows a side view of the craft with the hulls at maximum elevation above land
• Fig. 2 shows a side view of the craft in normal on-water travelling mode
• Fig. 3 shows a side view of the craft in normal on-land travel-at-speed mode In both Figs 2 and 3 and the remaining figures some of the finer detail of
• Fig. 1 is omitted for clarity.
• Fig. 4 shows an outward view to the left from a plane just central of the
• Fig. 5 shows the drive unit and depth control means in side view
• Fig. 6 shows a cross-section through a hull exploded from a
• Fig. 7 shows tail adjustment means
• Fig. 8 shows a plan view from above. Modes for carrying out the invention
• an amphibious catamaran has two long, non-rigid, substantially cylindrical, partly inflatable hulls 1 ,2 perhaps 6 to 7 metres long. These may be spaced apart in parallel a distance so that, at least when deflated, the total width of the craft is at or within the maximum width allowed for road travel without an oversize permit being required.
• the hulls are kept in their positions by means of a framework 3 of sufficient strength to resist the high forces exerted on the hulls under certain conditions found on the water.
• the framework might be a fabricated stainless steel, or aluminium, or moulded fibre-reinforced resin composite, open-topped box structure comprising (but not illustrated) a floor and sides and ends and cross members, some of which might be hollow to provide emergency buoyancy or fluid storage spaces. As it is normally above water level the floor can be self-draining.
• the hulls are preferably of a diameter of about 650mm although that would vary from one craft to another, depending on the layout and weight etc.
• the outer 25mm could be a closed-cell soft or flexible foam wrapping 4 (Fig. 6) around each inflatable tube 5.
• the wrapping would be encased in the usual protective fabric 6 which would substantially or wholly provide the outer surface of the hull.
• the idea of the foam is to provide additional protection against deflation of the interior tubes (there being say three in all in series) if the hull should become snagged by a fish hook or impaled on some projection, such as a sharp rock.
• Shapes such as longitudinal strakes of closed-cell foam (not shown) could also be attached to or incorporated under the fabric. The foam helps the inflatable hulls to maintain their shapes as otherwise there is a tendency for them to deform. A craft with these hulls might draw about 300mm of water.
• each hull has adhered to a fabric layer 6 a semi-rigid external boot 7 comprising a band of suitable plastics material which can impart a suitable shape to the bottom of the hull while also protecting the underlying fabric against abrasion if the hull touches land during beaching etc.
• That reinforcement serves to partially rigidise the lower-most portion of the hull, while yet allowing much of the impact of waves against the hull to be borne by the flexible portion of the hull above it. It functions as a strong-back. Furthermore, it can serve as a mounting for a keel 9, which might be necessary to improve directional performance and to stop chine-walk.
• the boot 7 generally has a cupped shape and it might be just, say, 150mm wide or it might encase the lower third of the hull, for instance. It can be extended to the forward part of the hull and a more appropriate shape in that area would be a "V" shape, possibly with a packer between the boot and the round hull.
• the boot is made of a semi-rigid material which retains its shape against permanent deformation, perhaps nylon or polyethylene, and must be able to be adhered or welded to the protective fabric 6.
• a modification is to have an inner "extension'"! 0 of the boot to form a semi-rigid strong-back internal of the fabric 6 but separated from an inflatable tube 5 by an innermost layer of foam 11 while being embedded in outer foam layers and overlaid by the fabric.
• This extension 10 further reduces the tendency for deformation of the hulls and provides an improved mounting frame for a keel.
• the extension would act in conjunction with the boot 7 its shape might be completely different.
• it might be provided as a narrow beam with its depth arranged to be vertical in use as shown in Fig. 6 and the depth might alter along the hull length.
• the boot or preferably any keel mounted on it, can be grounded by lowering to act as a brake for the craft upon transition from water to land, if the approach is made too fast.
• Each hull 1 ,2 is fastened to the framework 3 by means of a bolt-rope track coupling 12,12'; 13,13' on either side of the hull top centre-line.
• the inflation of the hull is preferably from the turbo-charger of a turbo-diesel motor 14. This provides a large quantity of low pressure air and also provides a means of quickly evacuating the air from the hulls. There would be suitable attachments (not shown) to the turbo-charger inlet and outlet and a suitable manifold (not shown) to the inflatable tubes.
• the three serially-mounted tubes which are inflatable within each hull may be removed through side access flaps (not shown) in the outer covering fabric 6 and slits in the underlying foam,for repair purposes when needed.
• the objective of the hull design is to provide a design which acts well as a displacement hull, is capable of planing efficiently, which is easy to service or repair, and which is relatively resistant to damage while providing a means of absorbing as much of the shock forces caused by water impact as possible.
• the boots 7 help with ride softness by retaining the hydrodynamic round shape of the hulls on impact with a wave, thus maintaining the speed of the craft.
• detachable rigid sealed containers (not shown) adapted to carry tools, equipment and supplies but also capable of functioning as additional flotation in a case where the craft is under a heavy load or when travelling through rough seas.
• inflatable tubes 5 might themselves contain emergency inflatable tubes (not shown), held up high out of harm's way when deflated, which can be filled with air from the turbo-charger, or emergency air reservoir, if ever needed.
• the bow or nose 15,16 of each hull can include a tapered closed-cell solid foam core, overlaid by said sheath of closed-cell flexible foam, which in turn is overlaid by the protective fabric.
• the nose is preferably able to be tilted up to a beaching position via a double-acting ram 17 as shown in Fig. 1.
• each stern or tail section 19,20 of each hull is able to be pushed down or pulled up, or both, with respect to the remainder of the hulls 1 ,2 by tail adjustment means preferably operating via a double-acting ram 18 (Fig 3 and Fig 7).
• Each tail 19,20 is also preferably able to be selectively deflated to enable the tail to be pulled up and contracted to facilitate raising or lowering of a rear land wheel such as 42 past the tail or stern as is shown in Fig. 7.
• the motor 14 is supported by the framework 3 as is a drive unit 21 for water propulsion.
• This may be a propeller or a jet drive.
• the preferred option is an hydraulically driven propeller 22 (Fig. 5) mounted on a depth control means 23 which includes a parallelogram linkage enabling the propeller to be lowered deep enough to function properly below the foul water created in the tunnel between the hulls, while enabling it to be raised high enough to avoid damage when the craft is on, or close to, land, maintaining trim all the while.
• a single or double-acting ram 27 controls propeller height.
• Conventional stern-legs are not strong enough nor do they have sufficient reach, nor maintain trim when raised. They could also foul the legs or arms 54,55 of the rear sub-frame 45 (yet to be described) if raised while at or close to a full-lock position as the distance between the rear legs is only about 900mm.
• the top 24 and/or bottom 25 arms of the parallelogram linkage are adjustable in length to alter the trim of the propeller.
• the top and/or bottom arms preferably incorporate double-acting pneumatic or hydraulic rams such as ram 26 to effect length adjustment.
• Rotation of the parallelogram linkage, or the propeller mounted on it, about a substantially vertical axis such as 29,29', in use, for steering the craft on water, is achieved by another hydraulic motor or a ram or rams (not shown).
• a conventional outboard motor can move only about 30°to either side of centre but the system for this craft preferably allows much more turning.
• the propeller is hydraulically driven via a, usually unsubmerged, reversible hydraulic motor 30 driving a substantially vertical partially submerged shaft (not shown) which drives the propeller via a submerged pair of bevel gears (not shown) in use, all submerged parts being suitably encased in casing 31 and perhaps water-cooled as well.
• the drive to it from its hydraulic driving motor 30 is via a bevel gear pair giving the appropriate step- down from the comparatively high-rotating hydraulic motor.
• the diesel motor 14 might rotate at 4200 rpm and the hydraulic pump or pumps (not shown) driven by it likewise.
• the propeller motor 30 might rotate at 3600 rpm in which case the step down might be 1 :1.25 for a 15 inch (375mm) diameter propeller.
• a propeller shroud 32 (shown schematically) is able to be lowered close to the top of the propeller, or raised away by shroud control means (not shown), to suit water conditions, to increase propeller thrust. It needs to be able to be totally removed from the water when underway to reduce drag. Subframes
• Three land wheels would be capable of supporting the craft on land but there are preferably four for better stability.
• These land wheels 40,41 ; 42,43 (Fig 8) are supported for rotation about their substantially horizontal axes on, and at, the extremities of sub-frames 44,45 which are able to be moved, preferably independently, via height adjustment means 46, 47 (shown in Fig. 1 only), with respect to the framework 3, from a position, where the land wheels 40-43 stably support the catamaran for travel on land with the hulls clear of the land, and a position where at least the land wheels associated with the front sub-frame, are raised upwardly beyond the bottoms of the hulls and, usefully, to other positions as well. Preferably all land wheels are so raised.
• While the land wheels may be located inboard of the hulls, extra stability may be gained if at least one pair of them, perhaps the rear pair 42,43, are more or less in line with the hulls 1 ,2 but to the rear of them. Balancing factors may mean that the rear sections of the hulls may need to be deflated to get them out of the way when such land wheels are to be moved past the tails 19,20 as has been described with reference to Fig. 7.
• the sub-frames 44,45 must be lowerable quite quickly, perhaps under computer control, so that beaching is achieved speedily and accurately and without needing to disengage the propeller, if that is the means of water propulsion, to minimise the chance of a following wave swamping the craft and also perhaps to maintain approach speed thus facilitating traverse over difficult land with limited tractionability.
• the angle of pivoting arc could in theory be as much as about 90° to give maximum elevation, but in practice a lesser angle will enable a more stable arrangement; for example the amount of movement about a pivot 48,49 could be about 55°.
• each sub-frame 44,45 may be about 1.6m and the land wheel, provided as a conventional wheel, might have a diameter of about 1m.
• the legs or arms 52,53; 54,55 (Fig. 8) of the sub-frames might conveniently be provided in part by hollow tubes and suitable tubes might be aluminium mast sections or preferably, for corrosion resistance, stainless steel. These could be designed to provide air reservoir tanks and also hydraulic fluid reservoir and cooling tanks. The ends of the tubes might in any case be sealed to increase overall flotation.
• the front and rear sub-frames 44,45 are suitably hinged or pivoted on the framework 3 for independent pivotal movement about substantially horizontal, substantially parallel, axes 48,49 which are substantially perpendicular to the straight-ahead line of travel of the craft in use, and the height adjustment means 46,47 may possibly include air rams (sometimes called bellows or pneumatic actuators or springs) adjacent the hinge axis and powered by an on-board compressor (not shown) driven by the motor 14. While pneumatic bellows provide a useful amount of flotation compared with other options, they have limited travel and are single-acting and for those and for other reasons double-acting hydraulic rams such as 50,51 are preferred.
• air rams sometimes called bellows or pneumatic actuators or springs
• Hydraulic raising and lowering is faster than pneumatics and it is important that the drag created by the lowering of the sub-frames and associated land wheels be minimised in order not to unduly slow the motion of the craft. Hydraulics allow fast raising and lowering and also allow a greater arc through which the sub-frames may be swung. The improvement over pneumatics might be of the order of 25°.
• the sub-frame legs or arms 52-55 might terminate in an axle or crossmember such as 56,57 (Fig 8) which supports at each end an hydraulic motor (not shown) driving an attached land wheel.
• Kingpin assemblies (not shown) allow for ram-actuated steering (not shown) of all the land wheels. When land speeds are low all may be steered, but when land speeds are to be higher then the preferable rear steering ram or rams (not shown) might be locked, with the land wheels in a straight-ahead position, to give increased stability of the craft, so at higher speeds on land steering is via the front land wheels alone.
• locking means (not shown) to mechanically, but releasably, lock the sub-frames in selected positions to reduce stresses on their operative hydraulic systems.
• the preferable suspension system uses hydraulic raising and lowering of the sub-frames 44,45 via double-acting hydraulic rams 50,51 with at least one sealed-gas spring (not shown) for example of the kind used on CITROEN [Trademark] cars.
• the hydraulic circuit (not shown) supplying the hydraulic rams preferably includes multiple, sealed-gas springs (not shown) at least some of which are selectable to enable choice of suspension firmness.
• the sub-frames 44,45 might act as prime means of access to, and egress from, the craft.
• the rear sub-frame 45 may be provided with a stepped cover (not shown) so that when the sub-frame is in the lowered position, whether on land or in the water, it can be used for access to the input station 59 or any deck of the craft.
• the rear sub-frame with suitably strong hydraulics, might be useful as a loading device to be lowered under some object to be loaded onto or off the craft to help lift it out of, or lower it into, the water. Otherwise with onboard hydraulics an on-board crane (not shown) could easily be provided for some applications where it would be useful.
• sub-frame is suitably constructed it might be transformable to, or useful as, extra temporary decking while not required for landing purposes.
• the two spaced apart rear land wheels 42,43 supported on the rear sub-frame 45 have a track which preferably substantially equals the maximum width of the craft across the hulls 1 ,2. This gives maximum stability while yet facilitating road travel.
• the sub-frame extremity terminates in the pair of land wheels on a short axle 56 such that the land wheels 40,41 lie in the space between the hulls 1 ,2 with room for turning when steered, with a central axle pivot axis (not shown) running longitudinally to create a vehicle suspension of three points similar to that used on many agricultural tractors.
• a central nose cone 60
• the hydraulic motors (not shown) for the land wheels might provide means of braking the craft as well as driving it.
• the land wheels When such a craft is being beached the land wheels would preferably be automatically lowered as the craft neared shore, utilizing a sensing device (not shown) adapted to cause lowering when the water floor-level was say 400mm below the hulls but there needs to be a nice balance between the land wheels making ground contact too early and having no traction, and making contact too late when the hulls might get grounded and damaged.
• the front sub-frame 44 might be lowered before the rear sub-frame 45 if necessary to facilitate landing.
• an aerofoil (not shown) on the sub-frame, perhaps forming a rear axle 57, the aerofoil being adapted to provide framework 3, and thus hull, lift when the rear sub-frame 45 is lowered into water while there is forward motion of the craft.
• rear rams (such as 18 in Fig 7) can be adapted to deflect the sterns or tails 19,20 of the hulls downwards which will provide framework lift by virtue of the craft's motion forward. Such a mechanism might conversely provide tail lift to reduce the planing surface and increase on-water speed. Variation side to side could enable a trim-tab like function to counter forces in reaction to propeller torque, uneven loading, wind forces or fast-turning forces.
• each hull at the tails 19,20 is selectively deflated when beaching or un-beaching the craft, and maybe for road travel at speed and curled by means of a multistage hydraulic ram (such as 18) in a radius tight enough for such a large land wheel to pass around it (as shown in Fig 7 to some extent). This could apply to both the bow and stern sections of the hulls depending on track width.
• An advantage of deflating the tail of each hull during beaching is that this raises the front of the craft and assists beaching.
• the height adjustment means 46,47 thus preferably enables each sub-frame 44,45 to be independently (if desired), positioned in at least 3 positions namely: A fully raised position (as shown in Fig. 1)
• the craft might be skid-steered.
• the front land wheel or land wheels might be mounted on a substantially vertical pivot for castor action while the rear land wheels would be able to be selectively braked and/or oppositely driven, independently.
• the rear land wheels could, as earlier defined, take the form of track assemblies (as might the front) to reduce land pressure. It is even envisaged that the land wheels could take the form of computer controlled feet for human-type walking on the land surface.
• An input station 59 is provided on the craft for any person who is to operate the craft on water or on land or both, and that person might be required to exercise judgement as far as lowering or raising of the land wheels was concerned during launching or retrieval of the craft if that function was not automated. It is, of course, possible that there may be no person on the craft at any time, in which case the input station would be occupied by a receiver (not shown) to receive remote control signals or there could be a combination of such.
• the input station may include a simple stand-up steering position or a fully enclosed cabin.
• the major ultimate power to effect movement on the craft comes from hydraulic motors or rams. These are preferably driven from a pair of series mounted hydraulic pumps (not shown) directly coupled to the output shaft of the turbo-diesel motor 14 which would be about 150 to 200HP (110-150kW).
• the diesel motor would also preferably operate a generator (not shown) to provide an electrical energy supply and also an air compressor (not shown) providing air at high pressure such as might be needed for operating power tools such as jacks or spreaders to free trapped people who might be held in the wreckage of a downed aircraft etc.
• a generator not shown
• an air compressor not shown
• a deck if provided on the framework 3, could enable a number of rescue pods (not shown) to be carried and quickly deployed to persons who might be in the water so that a number of people could be offered suitable support as quickly as possible.

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• 2001
  • 2001-12-07 CA CA002431224A patent/CA2431224A1/en not_active Abandoned
  • 2001-12-07 CN CNA01821844XA patent/CN1486253A/zh active Pending
  • 2001-12-07 EP EP01999485A patent/EP1355793A1/de not_active Withdrawn
  • 2001-12-07 WO PCT/NZ2001/000271 patent/WO2002045978A1/en not_active Application Discontinuation
  • 2001-12-07 AU AU2002216485A patent/AU2002216485A1/en not_active Abandoned
  • 2001-12-07 JP JP2002547739A patent/JP2004515396A/ja active Pending
  • 2001-12-07 US US10/433,929 patent/US20040065242A1/en not_active Abandoned

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