STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO SEQUENCE LISTING
Not applicable.
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to the vertical take-off field of aviation.
BRIEF SUMMARY OF THE INVENTION
There are many helicopters in existence today. However, helicopters rely on variable pitch rotor blades to maintain control and provide vertical lift, and the construction of helicopters with variable pitch rotors has resulted in limited operational ability when helicopters are used in forest areas, at high altitudes where the air is thin and when operating near steep mountains. Pitch varying mechanisms require frequent time consuming and expensive maintenance and a failure in the pitch varying mechanism on a helicopter often results in disaster due to instantaneous loss of control that cannot be overcome.
The present invention overcomes the need for varying the pitch of rotor blades while at the same time allowing vertical lift on take-off and directional control by providing a vertical take-off and land aircraft using a tiltable main rotor assembly high above the main body of the aircraft, which main rotor assembly comprises an assembly of blades and a rotor.
Vertical lift is obtained by the rotation of the main rotor assembly thereby forcing air in a downward direction by way of the angle of pitch of the blades. Rotation of the main rotor assembly is achieved using a power plant located between the main body of the aircraft and the main rotor assembly, which power plant is in the form of an engine assembly and is the main power plant forming part of the aircraft, and which main power plant is connected to the main body of the aircraft by a tilt enabling joint. The tilt enabling joint consists of numerous components, some of which provide the means to support the main body of the aircraft below the main power plant and allow the tilt enabling joint to have a tilting ability while other components provide the means to control and cause tilting motions in the tilt enabling joint during flight, thereby enabling controlled tilting to occur, such that the main power plant and the main rotor assembly can be tilted together as a unity relative to the main body of the aircraft in a controlled manner during flight, thereby providing a means for controlling the directional travel of the aircraft during flight and changing the aircraft's direction of travel.
During flight, rotational stability of the main body of the aircraft is maintained by means of an additional power plant in the form of an engine assembly attached to the aircraft which rotates a secondary rotor assembly, thereby pushing air primarily in a horizontal direction to counter the rotational force exerted on the main body of the aircraft by the rotation of the upper main rotor assembly, which said secondary rotor assembly comprises of an assembly of blades and a rotor.
As can be seen from the diagrams that follow, the present invention makes many of the components needed to construct a conventional helicopter obsolete, while providing an aircraft that can perform not only tasks normally performed by conventional helicopters but also other tasks that conventional helicopters cannot perform due to their configuration necessitated by variable pitch rotors.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which:
FIG. 1 is a view of the left side of one form of aircraft according to this invention.
FIG. 2A is a view of the left side of another form of aircraft according to this invention.
FIG. 2B is a view of the right side of the aircraft of FIG. 2A.
FIG. 3A is an enlarged view of a universal joint.
FIG. 3B is a rotated view of the universal joint of FIG. 3A.
FIG. 4 shows a version of the aircraft where the main power plant and main rotor assembly are at a significant distance from the main body.
FIG. 5 shows how variable pitch fins could be positioned on the aircraft.
FIG. 6 shows how one form of the aircraft could be used to evacuate people from the side of a building.
FIG. 7 shows how the main body of the aircraft of FIG. 4 could make contact with the side of steep mountain while the rotors are kept at a safe distance.
FIG. 8 shows that by keeping the main rotor at a large distance from the main body of the aircraft, the aircraft would be able to land among trees while the main rotor is kept above the trees.
FIG. 9 shows that as many as eight rotor blades can be assembled around a small rotor hub when blade pitch varying components are not required.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows one form of aircraft according to this invention.
Looking at the aircraft in FIG. 1 it can be seen that the aircraft comprises a main rotor assembly 1 at the top of the aircraft, which rotor assembly consists of an assembly of blades 2, 3 and a rotor 4. Rotation of the main rotor assembly is achieved by using a power plant 5, which is the main power plant on the aircraft and is below the blades 2 and 3. Vertical lift is obtained by the rotation of the main rotor assembly 1. Rotation of the main rotor assembly 1 forces air in a downward direction by way of the angle of pitch of the blades 2 and 3. The main power plant is connected to the main body 6 of the aircraft by a tilt enabling joint 7. The tilt enabling joint 7 allows tilting of the main power plant 5 relative to the main body 6 of the aircraft to occur in a controlled manner. A universal joint 8 is used to allow tilting to occur. The tilt enabling joint 7 is fitted with a combination of hydraulic actuators 9, 10 and springs 11, 12 and 13 that allow the tilting of the tilt enabling joint 7 to be controlled. As hydraulic pressure is applied to the front hydraulic actuator 10, it expands and in so doing tilts the upper section 14 of the tilt enabling joint 7 rearward, thereby compressing the rear spring 13. As hydraulic pressure to the front hydraulic actuator 10 is released, the rear spring 13 acts to tilt the upper section 14 of the tilt enabling joint 7 forward. When the main power plant 5 is tilted, the main rotor assembly 1 is tilted with it. Tilting of the main power plant 5 thus initiates changes in the direction of travel of the aircraft without the need to change the pitch angles of the blades 2 and 3. To counter the rotational force exerted on the main body 6 of the aircraft by the rotation of the main rotor assembly 1, FIG. 1 shows an additional power plant 15 attached to the upper section of the tilt enabling joint, which rotates a secondary rotor assembly 16. The secondary rotor assembly comprises blades 17 and 18, and a rotor 19. Rotation of the secondary rotor assembly pushes air in a primarily horizontal direction by way of the pitch of the blades 17 and 18. By forcing air to travel in a horizontal direction, the secondary rotor assembly acts to counter the rotational force exerted on the main body 6 of the aircraft by the rotation of the main rotor assembly 1. The main power plant comprises a single engine, and the additional power plant comprises a single engine.
The Springs 11, 12 and 13 shown in FIG. 1 can be replaced with gas pressurised struts, with the struts fitted in the locations where the springs are located in FIG. 1.
FIG. 2A shows a tilt enabling joint 1 consisting of hydraulic actuators 9, 10 and 10a being used to control the direction and angle of tilt, and a universal joint 8. As hydraulic pressure is applied to one hydraulic actuator 10 to extend it, hydraulic pressure on the hydraulic actuator 10a located directly on the opposite side of the universal joint 8 is released, allowing that hydraulic actuator 10a to contract, thereby causing controlled tilting of the upper section of the tilt enabling joint. The movement can be reversed by applying hydraulic pressure to hydraulic actuator 10a and releasing hydraulic pressure on hydraulic actuator 10. Hydraulic actuator 9 is used to control lateral tilting. With the main power plant 5 attached to the upper section 14 of the tilt enabling joint, when the upper section 14 of the tilt enabling joint is tilted so too is the main power plant 5 and with it the main rotor assembly 1. FIG. 2B shows the aircraft of FIG. 2A rotated horizontally 180 degrees to show the hydraulic actuator 10b on right side of the tilt enabling joint.
FIGS. 3A and 3B shows the universal joint 8 of the tilt enabling joint of FIG. 1. FIG. 3B is FIG. 3A rotated 90 degrees horizontally.
FIG. 4 shows a version of the aircraft where the main power plant and main rotor assembly are at a significant distance from the main body. The additional power plant is attached to the upper section of the tilt enabling joint 7, with the secondary rotor assembly attached to the additional power plant. This feature would allow both the main rotor assembly 1 and the secondary rotor assembly to stay high above the ground when the aircraft has landed in a forest. In another form of the aircraft, the additional power plant could be connected to the main power plant. The large distance is made possible and practical by eliminating the need for varying the pitch of rotor blades.
FIG. 5 shows the front of an aircraft similar to the one shown in of FIG. 4 and how variable pitch fins 20 and 21 could be positioned on the aircraft. The variable pitch fins could augment control of the aircraft, and could be used as airbrakes. They could also provide lift during high speed forward flight, such as wings on an airplane, since downwash from the main rotor assembly 2 would be directed to the rear of the aircraft, due to the tilting of the main rotor assembly in a forward direction and the distance of the main rotor assembly from the variable pitch fins. With the fins acting as air brakes while the main rotor is tilted forward, the main body of the aircraft could be made to rotate in a forward direction. At a rotation of 90 degrees, the aircraft could effectively be transformed into an airplane.
FIG. 6 shows how an aircraft according to this invention could be used as an evacuation vehicle for persons trapped in a building 22. An extension ladder 23 secured to the main body 6 of the aircraft is shown in extended form, with a basket 24 at the end of the extension ladder. FIG. 6 shows how a person 25 could be rescued from the building. The large distance between the main rotor and the main body of the aircraft makes the main body 6 of the aircraft act like a keel on a yacht, so that an extension ladder has a minimal effect on the ability to control the aircraft. The main body could be tilted slightly, while the main rotor assembly 1 could be maintained in a level position. While such a concept could have been used to save people from the twin towers in New York on Sep. 11, 2001, no existing helicopters were capable of rescuing people trapped in the twin towers and as a result many people jumped to their deaths. That is, people who could have jumped into a basket and be saved instead jumped to their deaths.
FIG. 7 shows how the aircraft of FIG. 4 could be used to quickly unload supplies on the side of a steep mountain 26, or quickly evacuate injured persons without having to use a winch. The relatively short distance between the main rotor and the main body of a conventional helicopter would prevent the main body of a conventional helicopter being able to make contact with such a steep mountain without a high risk of the rotor blades impacting with the mountain. As such, during military action in Afghanistan, helicopters operated by the US Army such as the Sykorsky H-60 (ie., Blackhawk) and the Boeing CH-47 restricted the US Army's ability, forcing landings on level ground, such as in valleys, and on at least one such occasion US troops were ambushed as a result when troops were landed into an enemy stronghold in a valley, not knowing prior to landing that the area was surrounded by opposing forces.
FIG. 8 shows how the aircraft of FIG. 6 could land between trees 27 and 28, while the main rotor assembly is kept above the tops of the trees. Cargo could be loaded and unloaded or injured persons evacuated without using a winch. The aircraft could land in an area such as a forest where the rotors of a conventional helicopter would impact with the trees. The aircraft would not require a cleared landing zone to land in a forest. In a war, the possible landing area would be less predictable by an enemy force, reducing the risk of an ambush around a cleared landing zone. If the aircraft was operated on a battle field and the aircraft was targeted by a heat seeking missile during flight, having the main power plant and the additional power plant located away from the main body of the aircraft would provide the occupants with a greater chance of survival than if the main power plant was attached directly to the main body of the aircraft if the missile caused a fire at the main power plant. The main power plant, the additional power plant, the main rotor assembly and the secondary rotor assembly are connected to the upper section of the tilt enabling joint. Neither the Sykorsky H-60, the Boeing CH-47, nor the much publicised Bell Boeing V22 Osprey is capable of landing among trees in a forest unless a cleared landing zone is created. Without the ability to land in a forest, such aircraft are unable to deliver cargo in a forest without dropping it and pick up cargo unless a cleared landing zone is created. Cleared landing zones are potential ambush sites during a war, as was demonstrated during the Vietnam war. The inability of the V22 Osprey to land in a forest without a cleared landing zone should be of concern considering that its main function is to be that of a transport aircraft and that over 10 billion $US has been spent on its development. Doubts about the V22 Osprey have existed for some time, and in an article in a magazine titled Aircraft & Aerospace, in the June 2001 edition, reference was made to the US General Accounting Office and its views. In an article titled “Tilting in the wind”, on pages 50 to 53, the article reads “The Bell Boeing V22 Osprey, under official development since 1986 and US Department of Defenses's sixth-largest weapons programme, came under fire from the Congressional accounting watchdog, the General Accounting Office . . . .” The article stated that $10 billion had already been spent on the program and that it was too expensive to cancel”. A transport aircraft almost 20 years in development and yet it cannot land in a forest. And while other patented vertical take-off and land aircraft such as the tandem powered aircraft with tilting tandem lifting mechanisms comprising rotors or a rotor and jet combination in tandem depicted in the Patent Cooperation Treaty application numbered PCT/AU2003/000816, and patented in Australia under patent number 781310 could land in a forest, the aircraft presented in this submission is able to operate with only one main lifting rotor.
The additional power plant and secondary rotor assembly could also be attached to the base of the tilt enabling joint or the main power plant.
FIG. 9 shows how eight rotor blades 29, 30, 31, 32, 33, 34, 35, and 36, can be assembled around a rotor hub 4 when space is not required for blade pitch varying components. This number of rotor blades would allow the rotor assembly 1 to be rotated at a lower rate of revolution than a rotor assembly with fewer blades, to achieve the same lifting ability, resulting in a relatively quieter aircraft. With yet a wider rotor hub, even more rotor blades could be accommodated. Having a high number of rotor blades would help the aircraft to operate in high altitude mountainous regions or hot regions, where the air is thin—existing helicopters struggle at high altitudes, and many helicopters have crashed when control has been lost due to thin air at high altitudes.
By being able to accommodate many more rotor blades than a conventional helicopter, the aircraft presented would be able to operate at higher altitudes than conventional helicopters. At low altitudes the high number of rotor blades would enable the main rotor assembly to maintain lift while the main rotor is rotated at a slow rate. By being able to rotate the main rotor assembly at a slow rate, the aircraft would be able to effectively become a stealth aircraft when compared to conventional helicopters without the need to spend absurd amounts of money on research and development as was the case with the now abandoned Commanche RAH-66. An amount of 6.9 billion in $US was spent before the futility of such a concept as the RAH-66 was realised, as documented in a magazine called Flight International, in March 2004, the 2-8 Mar. 2004 edition, the cover of which magazine read: “Commanche axed. Was 6.9 billion and 20 years simply wasted?”.
Patent Application
20070102569
