CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application

Serial No. 62/490,438, filed April 26, 2017, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to an electrically powered tail-sitter VTOL aircraft for providing transportation to passengers and/or cargo.

BACKGROUND

|0003] A vertical take-off and landing (VTOL) aircraft is one that can take-off and land vertically, relative to the ground. The VTOL can also hover relative to the ground. Additionally, the VTOL aircraft can transition between the vertical movement, relative to the ground, and horizontal flight. A vertical and short take-off and landing (VSTOL) aircraft is similar to the VTOL aircraft, but is also configured to utilize a short forward ground roll and resultant velocity to transfer apportion of the lift required by the aircraft to a wing, prior to take-off, to allow the aircraft to take-off with a higher take-off weight than could be achieved with only a VTOL aircraft.

SUMMARY

|0004] One aspect of the disclosure includes an electrically powered VTOL tail-sitter aircraft configured to transition between vertical flight and horizontal flight. The aircraft includes a payload module, at least one electrical power source, and a flight module. The flight module is operatively attachable to the payload module and includes a wing, landing gear, and a plurality of electric thrust generators e.g., electric engines. The landing gear is configured to operatively support the aircraft when positioned on the ground. The electric thrust generators are operatively attached to the wing. The electric thrust generators are configured to operate to provide thrust to the aircraft in response to receiving electric power from the at least one electrical power source. The wing is configured to selectively pivot about the pivot axis, relative to the payload module, to vary a flight path of the aircraft from between a first position and a second position. Each of the plurality of electric thrust generators pivot with the wing about the pivot axis, relative to the payload. The aircraft is configured for vertical flight when the wing is in the first position and the plurality of electric thrust generators are operating when the wing is in the first position and the aircraft is configured for horizontal forward flight, relative to the ground, when the wing is in the second position and the plurality of electric thrust generators are operating.

[0005] In another aspect of the disclosure, the aircraft includes three separable modules, a flight module, a payload module, and a ground module. The payload module may a passenger compartment of a car, including A pillars, C pillars, and other reinforcing structures along with other strengthening components. The ground module may include wheels, a transmission, a suspension, a battery, and any other components configured to drive the payload module on the ground. The payload module is selectively attachable and detachable from the ground module.

[0006] The flight module includes a structure and a wing. A joint pivotally connects the wing to the structure to allow the wing to pivot relative to the structure about a pivot axis located on a hinging point. The joint is located inside the structure, where the wing may rotates to a plane behind the hinging point. The center of gravity is adjusted as to be located on the hinging axis, thus providing longitudinal stability. The center of lift is located ahead of the hinging axis giving it a slight pitch up moment which can be adjusted.

[0007] In yet another aspect of the disclosure, the tail-sitter configuration employed in the design is configured to bear the load of the wing on two stanchions of the landing gear. The landing gear is made modular with linear actuators that actuate to deploy the landing gear during landing.

[0008] In another aspect of the disclosure, another configuration that may be employed for increasing the wing area and increasing the aspect ratio of the wing structure is described. It involves using of the landing gear as a wing surface which may be opened using electric linear actuators once the flight takes off vertically. In this configuration, the payload module is disconnected from the landing gear of the flight module and gimballed from a horizontal pivoting rod just ahead of the hinging axis and in the same horizontal plane as the hinging axis.

[0009] In yet another aspect of the disclosure, the components, systems, and assemblies of the aircraft include propellers, electric motors, batteries, battery management systems, controllers, inverters, thermal management systems, range extender systems that could be employed for prototyping the aircraft to get maximum efficiency, endurance, and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic isometric view of an electrically powered tail-sitter aircraft having a payload module and a flight module including a wing, with the wing oriented in a first position that is configured for vertical flight;

[0011] Figure 2 is a schematic top view of the VTOL aircraft of Figure 1, with the wing oriented in the first position;

[0012] Figure 3 is a schematic front view of the VTOL aircraft of Figure 1, with the wing oriented in the first position;

[0013] Figure 4 is a schematic right side of the VTOL aircraft of Figure 1, with the wing oriented in the first position;

|0014] Figure 5 is a schematic illustrative view of modules and flight transition of the tail-sitter aircraft generally shown in Figure 1;

[0015] Figure 6 is a schematic exploded side view of the tail-sitter aircraft of Figure 1, illustrating the flight module, a payload module, and a ground module, all separable from one another;

[0016] Figure 7 is a schematic isometric view of yet another embodiment of the tail- sitter aircraft of Figure 1, with the wing oriented in a second position that is configured for horizontal, forward flight;

[0017] Figure 8 is a schematic isometric view of the aircraft of Figure 6, with the wing oriented in the first position;

[0018] Figure 9 is a schematic isometric view of another embodiment of the tail-sitter aircraft of Figure 1, with the wing oriented in the second position;

[0019] Figure 10 is a schematic top view of the tail-sitter aircraft of Figure 9 with the wing in the second position and landing gear in a deployed position;

|0020] Figure 11 is a schematic front view of the aircraft of Figure 9 with the wing in the second position and the landing gear in the deployed position;

[0021] Figure 12 is a schematic side view of the aircraft of Figure 9 with the wing in the second position and the landing gear in the deployed position;

[0022] Figure 13A is a schematic isometric view of the aircraft of Figure 9 with the wing in the second position and the landing gear in the deployed position;

|0023] Figure 13B is a schematic isometric view of the aircraft of Figure 9 with the wing pivoted to be between the first position and the second position and the landing gear partially retracted as the aircraft transitions between vertical flight and horizontal, forward flight;

[0024] Figure 13C is a schematic isometric view of the aircraft of Figure 9 with the wing in the second position and the landing gear fully retracted, such that the landing gear is a lateral extension of the wing;

[0025] Figure 14A is a side view of the aircraft of Figure 13A;

[0026] Figure 14B is a side view of the aircraft of Figure 13B; and

[0027] Figure 14C is a side view of the aircraft of Figure 13C.

DETAILED DESCRIPTION

[0028] Referring to the drawings, wherein like reference numerals are used to identify like or identical components in the various views, Figures 1-4 show an electrically powered e-VTOL tail-sitter aircraft at 10. As will be explained in more detail below, the electrically powered tail-sitter aircraft 10 (hereinafter "aircraft") is configured to transition between flight in a vertical direction 24 and flight in a horizontal direction 25 to provide transport for passengers and/or cargo between locations. When not in use, or when loading/unloading the passengers and/or cargo, the tail-sitter aircraft 10 includes landing gear 26 that supports the aircraft 10 when the aircraft 10 is positioned on the ground 23.

|0029] The aircraft 10 illustrated in Figures 1-4 may be capable of operating in a vertical take-off and landing (VTOL) mode 27, a horizontal flight mode 28, as well as sustaining flight during a transition between the VTOL mode 27 and the horizontal flight mode 28.

[0030] With continuing reference to Figures 1-4, the aircraft 10 includes a pay load module 18, at least one electrical power source 30, a controller 31, and a flight module 32. The flight module 32 is operatively attachable to the payload module 18. The flight module 32 may include a structure 33, a wing 12, the landing gear 26, and a plurality of electric thrust generators 34.

|0031] The structure 33 may include a pair of stanchions 19 and a pair of arms 20.

The pair of stanchions 19 extend from the wing 12 in spaced and parallel relationship to one another, with payload module 18 disposed therebetween. The pair of arms 20 extend toward one another, from a respective stanchion to attach to opposing sides of the payload module 18. The arms 20 may be removably connectable to the payload module 18 to allow the payload module 18 to be selectively disconnected from the structure 33 of the flight module 32. [0032] The landing gear 26 is configured to operatively support the aircraft 10 when the aircraft 10 is positioned on the ground 23. The landing gear 26 may be operatively attached to the structure 33. In the embodiment shown in Figures 1-4 and Figure 9, the landing gear 26 includes a pair of bases 35 and a plurality of wheels 22. A base is operatively attached to the structure 33, proximate an intersection of the respective stanchion and the respective arm. In the embodiment shown in Figures 1-4, the landing gear 26 is in a fixed position, meaning the landing gear 26 remains in a deployed position, regardless of whether the aircraft 10 is positioned on the ground 23 or in flight. The wheels 22 may be configured to provide the utility of taxiing the aircraft 10 and generally allow for movement of the aircraft 10 on the ground 23.

|0033] The electric thrust generators 34 are operatively attached to the wing 12. The electric thrust generators 34 are selectively operable to provide thrust to the aircraft 10 in response to receiving electric power from the electrical power source 30. The electrical power source 30 may be a battery storage system or a battery management system. The electric thrust generators 34 are typically attached to the wing 12 at or proximate a leading edge 36 of the wing 12. The embodiment shown in Figures 1-4 includes four electric thrust generators 34 disposed in spaced relationship to one another across the leading edge 36 of the wing 12.

[0034] With reference to Figure 4, a pivot mechanism 39 is schematically illustrated at 39. The pivot mechanism 39 pivotally connects the wing 12 to the stanchions 19 of structure 33 such that the wing 12 is selectively pivotable about a pivot axis 40, relative to the structure 33 and the payload module 18, to vary a flight path of the aircraft 10 from between a first position and a second position. This pivotal connection between the wing 12 and the stanchions 19 of the structure 33 is configured to support vertical loads, lifting loads, and additional loads due to component loading during flight of the aircraft 10. By virtue of their attachment to the wing 12, each of the electric thrust generators 34 pivot with the wing 12, about the pivot axis 40, relative to the structure 33 and the payload module 18. Pivoting the electric thrust generators 34 with the wing 12 about the pivot axis 40 provides thrust vectoring, i.e., directs the thrust in an intended direction.

[0035 j Referring to Figures 1 and 2, the wing 12 includes the leading edge 36 and a trailing edge 37, opposite the leading edge 36. Side edges 38 along the wing chord extend to connect the leading edge 36 and the trailing edge 37. A side wing tip 21 may extend from each of the side edges 38, proximate the trailing edge 37. The side wing tips 21 may be used as flaperons 21 that pivot relative to the respective side edge 38 to assist in thrust vectoring during operation of the aircraft 10 in the VTOL mode, i.e., when the wing 12 is in the second position. The flaperons 21 may pivot relative in opposition to one another to provide a turning force (i.e., acting as an aileron), or may pivot in tandem to act together to assist with the lift/drag force (i.e., acting as flaps). The flaperons 21 may be constructed so as to pivot as a whole from a point on a root attachment of the fiaperon 21 to the wing 12, where the point is chosen to provide a desired balance of forces on the wing 12. Alternatively, a portion of the fiaperon 21 may be fixed relative to the wing 12, with an aft portion 21a hinged so as to move relative to the fixed portion to induce aerodynamic forces.

[0036J The wing may also include other control surfaces, such as rudders 15 and ailerons/elevators 16 proximate the trailing edge 37. Likewise, the payload module 18 may include control surfaces. As such, a rudder 15 may be operatively attached to the payload module 18 to provide additional stability and allow additional control of the flight of the aircraft 10.

[0037] The aircraft 10 is configured for vertical flight when the wing 12 and the associated electric thrust generators 34 are in the second position, as illustrated in Figures 1-4 and as illustrated in Figure 9 (see element 100-4). When the electric thrust generators 34 are selectively operating and providing thrust, and the wing 12 is in the second position, the aircraft 10 flies vertically. Likewise, the aircraft 10 is configured for horizontal, forward flight when the wing 12 and the associated electric thrust generators 34 are in the first position, as illustrated in Figure 9 as elements 100-7, 100-8, and 100-9. When the electric thrust generators 34 are selectively operating and providing thrust, and the wing 12 is in the first position, the aircraft 10 flies horizontally in a forward direction, relative to the ground 23.

[0038] Each electric thrust generators may include an electric motor 13 and a propeller 17. The electric motors 13 are operatively attached to the wing 12 and in electrical communication with the electrical power source 30. The propellers 17 are rotatably attached to the respective electric motor 13. In response to receiving electrical power, i.e., an electrical signal, from the electrical power source 30, the propellers 17 are configured to selectively rotate about a prop axis 43 and generate thrust to lift the aircraft 10 vertically when the wing 12 is in the second position, i.e., in a VTOL mode, and propel the aircraft 10 forward in the horizontal direction 25 when the wing 12 is in the first position. Further, with reference to Figure 1, the outermost pair of electric thrust generators 34 may be configured to selectively rotated in a first direction that is opposite a second direction of rotation for the pair of innermost electric thrust generators 34. This counter rotation between the adjacent electric thrust generators 34 with aid in controlling stability of the aircraft 10 while the aircraft 10 is in the VTOL mode (i.e., when the wing 12 is in the second position) and when the aircraft 10 is in a transition mode (i.e., when the wing 12 is rotating between the first position and the second position).

[0039] The controller 31 may be in operative communication with the pivot mechanism 39 and each of the electric motors 13 to selectively change the orientation of the wing 12 about the pivot axis 40 and to control rotation of the propellers 17 of each of the electric thrust generators 34.

[0040] Referring again to Figure 4, the payload module 18 may be operatively attached to the structure 33 such that the payload module 18 is movable in a fore/aft direction 42 to vary a position of the center of gravity (CG) of the aircraft 10. Allowing for the movement of the CG in the fore/aft direction 42 can provide improved stability to the aircraft 10 and optimized aircraft 10 control during aircraft takeoff, flight, landing, and transitions between vertical flight 24 and horizontal flight 25 illustrated in Figure 5.

[0041] With reference to Figures 7-8, a second embodiment of the tail-sitter aircraft is shown at 100. The landing gear 126 is a folding tripod type structure 145 with integrated control surfaces 144 to provide stability for the aircraft 100. The integrated control surfaces 144 may act as tail wing stabilizers during take-off and landing. The tripod 145 is in a closed position 146, i.e., retracted, during flight and the tripod 145 reopens or otherwise extends into a landing position 147 during vertical landing of the aircraft 100. The aircraft 100 may also include a suspension mechanism 148 at the center along with shocks 149 at legs 150 for supporting the tripod 145 and providing the tripod 145 with a cushioning effect upon contact with the ground 23.

[0042] Referring to Figures 9-12, 13A-13C, and 14A-14C, a third embodiment of the tail-sitter aircraft is shown generally at 200. The aircraft 200 includes a folding wingtip 251 that can be used to provide increased wing area and an increased aspect ratio, thus providing improved aerodynamic mission efficiency in horizontal flight 25 and additionally serves as the landing gear 226 for the aircraft 200. The combination of increased wingspan and the integration of the landing gear 226 into the wingtips 251 functions to make more efficient use of aircraft 200 structure and weight. Thus, an increase in the overall mission efficiency/range is achieved by reducing the load on the battery management system 30 in horizontal flight 25. The extended wing region provided by the extendable wing tips 251 is illustrated in Figures 13C and 14C. The folding wing tips 251 are mounted to structure 233 on opposing sides of the wing 212 where the wing tips 251 are configured to pivot about a folding axis 252. The payload module 218 is fixed to the structure 233 and the wing 212 is pivotally attached to the structure 233. Additionally, the flight module 232 may include a tail 253 that includes a plurality of control surfaces 16 configured to provide additional dynamic stability during flight operations. Figures 13A-13C and 14A-14C illustrate the aircraft 200 in the three modes of flight from the vertical flight mode 27 shown in Figures 13 A, 14A, transition flight 29 shown in Figures 13B, 14B, where the wing 212 and the wing tips 251 start to approach being synced together to start generating lift together, then to the transition into horizontal flight mode 28 shown in Figures 13C, 14C where the wing 212 and the wing tips 251 are fully synced together.

[0043 j Figure 10 describes the 3 modules that make up the aircraft 200. Each module can be modified for different purposes and can be integrated with each other to obtain the goal of safe and point to point passenger mobility or cargo delivery etc.