AU601752B2 - Heli-hover amphibious surface effect vehicle - Google Patents

Description

4- S601 75

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0 00 1 1 Form 10 PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Tifte: int. CI: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: S' ated Art: This document contains the amendments made under Section 49 and is correct for prinling C 7 NLame of Applicant: TO BE COMPLETED BY APPLICANT ~r w

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I Address of Applicant: /C73 C.t6 -7J 'JS3 ^2LE^AS-- /i Actual Inventor: PR// Ok^6^ )J9^/,V67~A/ Address for Service: /O/37 -C'7o1J" /V f .Y rY. Complete Specification for the invention entitled: The following statement is a full description of this invention, including the best method of performing it known to me:- SNote: The description is to be typed in double spacing, pica type face, in an area not exceeding 250 mm in depth and 160 mm in width, on tough white paper of good quality and it is to be inserted inside this form.

14599/78- L Printed by C. J. THOMPSON, Commonwealth Government Printer, Canberra I ~r u- i Title: HELI-HOVER AMPHIBIOUS SURFACE EFFECT VEHICLE The invention relates to an air cushion vehicle propelled and stabilized by a fixably attached aerodynamic heli-rotor system incorporating variable pitch adjustable blades of aerodynamic configuration having a controlled collective and cyclic pitch component.

Air cushion body structure of vehicle is integrally equipped with one or more powered lift fans to supply pressurized air through the deck structures to under compartmental base cavities by a suitable ducting means integrally located within the confines of the air cushion fuselhge body structure. Vehicle is maintained in aerostatic suspension, clear of the surface by any of the known air cushion containing means common to air cushion vehicles such as cones, fingers, vents or segmented skirts.

Tail rotors or thrusters located on the aft end of the vehicle or craft control the torsional forces generated by the rotors as well as assisting with the maneuverability of the vehicle.

Aerodynamic heli-rotor assembly is supported well above the integral deck superstructure on a pylon structure so as to maintain the rotor in free open air c passage allowing' the rotor to perform the normal flight functions familiar to heli-rotor systems equipped with collective and cyclic pitch components of variable pitch adjustments to their rotor blades.

20 All operational stability and trust of the heli-hover vehicle occurs by the action of K the flying aerodynamic bladed rotor system within the unobstructed air body above and in proximity to the lower structure of the vehicle formed as an air ;cushion vehicle.

Said air cushion vehicle housing an integral air cushion containing means to support the craft in an aerostatic state when pressurized by an integral gas Ipressurizing means such as one or more powered fans to maintain the body of pressurized gas between the air cushion containing means and the ground or water surface in frictionless suspension.

The pylon supported flying heli-rotor system is positioned high above and clear of the air cushion vehicles deck superstructure to allow for the rotors location in an 0 unobstructed passage of an unwarned air supply during the crafts surface S- movements. The flying heli-rotor assemblies being fixably attached as integral .'iI- 2 part of the supporting air cushion structure body by an appropriate superstructure pylon transmits stability and thrust to the vehicle. Stability and thrust is solely the product of the heli-rotors aerodynamic function.

The invention overcomes the inherent problems of maneuverability and side drift associated with conventional hovercraft equipped with deck mounted thrusters.

Trim of craft is effectively improved by the lift moment of upward pull of horizontally rotating propulsion heli-rotor or rotors. Main rotor collective pitch together with cyclic pitch adjustments in conjunction with tail rotor control, allows for precise maneuverability of the craft in all directions at low or high speed providing effective braking and speed control due to main rotor revolutions being maintained and thrust controlled by pitch adjustments. Noise levels are drastically reduced by eliminating the conventional high speed air screw propulsion units. The craft has the ability to climb over obstacles which would otherwise stop a conventional hovercraft propelled by deck mounted airscrew Su.. thrusters.

Stability is vastly improved when compared with the conventional aerostatic hovercraft resulting from the pendulum support of the overhead rotor operating in true aerodynamic flight function also tends to eliminate reverse banking of the hull in turns. This flight function of the rotor also assists forward trim by keeping the bow up, thereby preventing bow plough-in and instability of craft. Skirt life is markedly improved by the action of these factors. On land the conventional ct I hovercraft runs away in an uncontrollable manner on down hill slopes whereas a. with the present invention precise control can be maintained under all l circumstances due to thrust control provided by 360 degree cyclic movement of CC,' thrust and lift vector from the heli-rotor. A referring to a structure shown in Australian Patent No 79167, 17 March 1975 by Herbert Leonard Dobb, Titled:j^ "Air Cushion Pontoon Freight Helicopter." From these specifications and claims it will be noted a severe stability problem exists, whereas the present heli-hover t invention overcomes the necessity for a twin divided pontoon structure to provide stability, by using a single main hull of wide beam and length proportions utilizing the conventional compartmental under cavity sections of conventional hovercraft with segmented skirts attached. The control and load carrying areas are integrally built into the main superstructure in conjunction with the rotor pylon support structure whereas in the known art the hull is composed of two separate Spontoons, each with their own fan and duct system for the lift air suspension, with 3 the load carried on a movable platform located between the two pontoons.

Loading centre of gravity is critical in this known invention whereas with the present invention the aerostatic support area extends well forward, aft and well out each side of loading area with the above mounted rotor assembly providing the necessary stability in addition to hull support area. The high above deck mounted horizontal or near horizontal rigid mounting of the rotor assembly in the present invention maintains the extending rotor blade tips well clear of water or land surface in a free flying state, whereas with the before described known invention the rotor blades are tilted forward to axially provide thrust for forward movements. This angle is described as up to 45 degree forward which bring the fast moving rotor tips close to the ground surface causing hazardous operation and the high risk of catastrophic damage occurring in the event of rotor striking an obstructions. The pendulum like support for the hull which the rotor provides in the present invention is lost when the rotor assembly as in the known invention 4o, is tilted forward at up to 45 degrees to operate an axial fan. An important factor with the control of hovercraft, is side drift, caused by cross winds to the heading direction. By maintaining the rotor in a near horizontal plane, as in the present invention, the ability to equalize this drift by adjustment of the cyclic pitch setting is most effective, whereas in the known type with the rotor blade tilted down towards the direction of travel of the vehicle as an axial fan, cyclic pitch adjustments would be ineffective. The presert- 'avention has a large hover base area compared to the rotor swept area. The proportion would vary from 1 to 1, up to 6 to 1, as compared to the known Dobb invention which has a proportion of a much larger rotor swept area than the area of the twin pontoons. This ratio is a necessary part of the helicopter flight characteristics which are a claimed feature of this known invention. The present invention is not intended to operate out of aerostatic suspension during motion and the craft is not intended to lift into tianslational flight at any time due to the dead weight of the vessel at any stage of ,loading being far above the designed vertical lift capacity of the rotor assembly.

Propulsion as a hovercraft supported by aerostatic suspension is solely governed by the degree of cyclic pitch influencing the rotor disc incidence and attitude 401 within a 360 degree rotation adjustment. The rotor shaft remains in a near um t 9 perpendicular fixed axis in relation to the hull at all times. With the vehicle being propelled by the rotor fixed in a near horizontal state the down washl has a flattening effect on the water surface adjacent to the craft assisting to moderate C .i 44 rough sea conditions, thereby overcoming plough-in and at the same time improving the aerostatic lift moment of hover hull by increasing the ambient air pressure over the lift air fan intakes and adjacent to the external skirt areas to contain leakage and so maintain a high pressure within the plenum chamber of the hover fuselage body. Rotor down wash lessens and disperses spray deflecting it well away from the vessel, thereby improving visability and maintaining a dry superstructure and deck surface.

The invention has been devised to provide a novel firm of amphibious craft capable of maneuvering over inhospitable terrain, water, snow, ice, bog or marsh land in an economical and efficient manner.

The device would have wide application of use, providing a completely new concept to the conventional hovercraft for transport needs, tourist, rescue, arctic exploration, agriculture, commercial and defence applications. The heli-hover 4 amphibian would have specific military application in the role of, Troop assault landing craft," and as "Hover Tanks" for use over snow, bog or marshy terrain, able to maneuver from ocean going transport to land mass.

fi The device can be produced in an economical manner and readily put into o 4.4 service. Further advantages will be apparent from the following description.

According to the invention the device consists of a main flat fuselage body of round, oval or oblong shape which forms the main hovercraft sections. Attached to the upper surface of this fuselage body are formed, the control, passenger, cargo superstructure, and rotor pylon to support the rotor assemblies. Antitorque and maneuvering means are fixably mounted on the aft end of the craft.

Deck area may be sealed or open with webbed or formed superstructure fixably supporting rotor assembly on a pylon structure standing well above and clear of deck area. Also incorporated within or adjacent to the main hover fuselage are the lift air fan or fans and drives which supply pressurised lift air to the lower air I cushion support cavity contained within the peripheral flexibly segmented skirts with compartmented under cavity sections equipped with the usual air-cushion containing means as part of the main hover fuselage. Built- in static buoyancy is incorporated within the main fuselage structure to support craft when at rest on water and not operating in hover mode. Craft can be produced in various configurations depending on application, using single, co-axial contra-rotating Li heli-rotors as single installation or multiple installations, arranged in tandem, dual i Zii or quad formation either as meshing or non-meshing assemblies. Various configurations and design of air cushion support systems and skirts can be incorporated on the underside of main fuselage to provide an. efficient hover air cushion base. The invention will now be shown in following drawings in which:- Fig.l; show the top view of a craft with single heli-rotor with tail rotor arrangement, Fig.2; shows Fig.1 in elevation. Fig.3; shows a perspective view of invention applied to a vehicle ferry or transport vehicle. Figs.4 and 5; show, respectively, a top view and a side view of a craft in accordance with the present invention, having duel heli-rotors with tail rotor arrangement; and Figs.6A,7A and 8A; diagramatically show top views while Fig.6B and C, 7B and C, and 8B and C show diagramatic side views of paired, contra-rotating heli-rotors in single configuration, tandem configuration and quad configuration, respectively.

Figures 1 and 2 show a preferred application of the invention as conceived applied to a vehicle or vessel to be used over land, water, swamp, snow, ice or in r, rough formed guideways as a passenger, cargo carrying transporter. The main hovercraft fuselage body 1 houses the usual air-cushion containing means such as single or multiple plenum-chambers with their outer peripheral and divisional k ,,,borders arranged in any of the known forms. 9. Above the roof of the suspension support compartment are the fan chambers with ducting leading to outlets located in the roof of the suspension compartments to so provide the pressurized lift air generated by the lift fan 4. Lift air passes into the distributer compartment and then via the ducting to spaced air outlets located in the ceiling of each plenum compartment or to the segmented cones or fingers used on the peripheral skirts 9. These skirts may be independently supplied with pressurized air from a separated fan system, depending on model and application. Main fuselage body 1 has built-in static buoyancy tanks or foam filled compartment to support the craft when not in hover mode while resting on water. Skids or other fixed or retractable structure act as support means on hard surfaces. The deck superstructure 2 supports the heli-rotor assembly 7 or can have independent pylon structure integral with air cushion body structure 1 depending on model and application. The lift fan assembly 4 providing suspension lift air can be located where shown aft or at any other suitable position on the deck superstructure depending on model and application. Craft can have a single hell-lift rotor assembly as shown at 7 or can have a multiple of assemblies arranged in tandem, dual or quad formation or single or multi-rotor configuration depending on model and application as shown in Figures 4, 5, 6A-6C, 7A-7C and 8A-8C. Rotor blades 8 have collective and cyclic pitch functions similar to the normal helicopter controls. The anti-torque means 5 is located aft and may be directly coupled to main rotor by mechanical or hydraulic means, rotor 6 may be variably pitched. Both the main rotor and the tail rotor variable pitch characteristics are controlled from the main control station. Rear anti-torque mode can be by rotor or pressurized air thruster. Figure 3 of the drawings shows an application of the concept of the invention to a vehicle ferry or cargo transporter. The embarking or disembarking ramps 10 can be set up as a retractable or hinged action to act as sea doors when the vessel is in operation.

To those skilled in the art to which the invention relates; many changes in construction, design and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and descriptions herein are purely illustrative and are not intended to be in any sense limiting or being restricted to a precise form.

14 May 1990. A.G. YARRINGTON i I I *r I *e 1- L It IC C

ICC

1.,1Id 7, ABSTRACT OF THE DISCLOSURE The invention relates to an air cushion vehicle propelled and stabilized by a fixably attached aerodynamic heli-rotor system as familiar to coventional helicopters. Propulsion and stability of the air cushion vehicle by one or more heli-rotor assemblies perform the true flight functions of collective and cyclic pitch of the rotor blades to provide precise propulsion and maneuverability. At least one integrated fan provides lift air through the deck superstructure to the air cushion containing means to cause aerostatic suspension of the hull in a frictionless state.

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Claims (6)

1. A air cushion vehicle propelled and stabilized by at least one fixably attached aerodynamic heli-rotor system incorporating variable pitch adjustable blades of aerodynamic configuration having a controlled collective and cyclic i.'ch component; said air cushion vehicle integrally equipped with at least one powered lift fan to supply pressurized air to the under compartmental base cavities of the air cushion containment means by a suitable ducting means integrally located within the confines of the air cushion body structure; a deck superstructure fixably attached to said air cushion body structure incorporating at least one pylon structure to support at least one heli-rotor assembly in an elevated position, well clear of deck superstructure to allow heli-rotor to perform true aerodynamic flight functions; said hell-rotor assembly being driven by a substantially vertical fixed shaft; anti-torque means provided on aft end of air cushion structure as a S.fixably attached component of deck superstructure; and a drive means operatively connected to said heli-rotor assembly and anti-torque means for propelling the craft.

2. A air cushion vehicle according to claim 1, including a contra rotating rotor positioned co-axially with said heli-rotor assembly.

3. A air cushion vehicle according to claim 1, including an additional heli-rotor assembly, wherein said rotor assemblies are positioned in a tandem configuration.

4. A air cushion vehicle according to claim 3, including additional heli-rotor assemblies wherein said rotor a ;mblies are positioned in a dual formation.

A air cushion vehicle according to claim 3, including additional heli-rotor assemblies wherein said rotor assemblies are positioned in a quad configuration.

6. A air cushion vehicle according to claim 1, wherein said anti-torque means comprises a tail rotor attached to an elevated tail structure on the aft end of the air cushion structure as a fixably attached component of the deck superstructure. A.G. YARRINGTON DATE: SIGNED: L 1 1 0C,