Wing Flap System for Flying Car

(19) TZZ¥___T

(11) EP 3 418 184 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication: (51) Int Cl.: 26.12.2018 Bulletin 2018/52 B64C 9/16 (2006.01) B60F 5/02 (2006.01)

(21) Application number: 17176991.2

(22) Date of filing: 20.06.2017

(84) Designated Contracting States: (72) Inventors: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB • MACANDREW, Kenneth Douglas Alexander GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO 841 06 Bratislava-Zahorska Bystrica (SK) PL PT RO RS SE SI SK SM TR • URIK, Tomas Designated Extension States: 908 41 Sastin-Straze (SK) BA ME • ROOMS, William Simon Designated Validation States: 841 02 Bratislava (SK) MA MD (74) Representative: Finnegan Europe LLP (71) Applicant: AeroMobil R&D, s. r. o. 1 London Bridge 82106 Bratislava-mestska cast Podunajske London SE1 9BG (GB) Biskupice (SK)

(54) WING FLAP SYSTEM FOR FLYING CAR

(57) A wing and flap system for an aircraft compris- mechanism for moving the flap between the first, second, ing: a wing (16); and a deployable flap (30) connected to and intermediate positions, comprising: a driven toothed the wing, the flap being moveable between a first position pinion (52) mounted in the wing; and first (36) and second in which a trailing edge portion of the wing substantially (38) struts, each substantially aligned with a plane includ- overlaps the flap and the angle of incidence of the flap ing a chord of the wing and extending between the pinion is substantially the same as the angle of incidence of the and the flap, each strut having a toothed rack (40, 42) wing, and a second position in which the trailing edge engaged with the toothed pinion such that operation of (33) of the flap is behind the trailing edge (34) of the wing the pinion moves each strut in a direction substantially and the angle of incidence of the flap is greater than that aligned with a plane including a chord of the wing, the of the wing, and an intermediate position between the first strut being connected to the flap relatively closer to first and second positions, in which the trailing edge of the leading edge thereof, and the second strut being con- the flap is behind the trailing edge of the wing and the nected to the flap relatively closer to the trailing edge angle of incidence of the flap is substantially the same thereof. The system can be used in a flying car having asthat ofthe wing; andfurther comprising a flapoperating foldable wings. EP 3 418 184 A1

Printed by Jouve, 75001 PARIS (FR) 1 EP 3 418 184 A1 2

Description pinion mounted in the wing; and first and second struts, each substantially aligned with a plane including a chord [0001] This invention relates to a flap system for use of the wing and extending between the pinion and the on an aircraft. In particular, it relates to such a system flap, each strut having a toothed rack engaged with the for use on a convertible vehicle that is configurable for 5 toothed pinion such that operation of the pinion moves both road and flight use, sometimes called a "flying car". each strut in a direction substantially aligned with a plane [0002] Flaps, such as deployable trailing edge flaps, including a chord of the wing, the first strut being con- are structures used to adjust the aerodynamic properties nected to the flap relatively closer to the leading edge of a wing, typically to change its lift characteristics. By thereof, and the second strut being connected to the flap extending trailing edge flaps, the wing can be adapted 10 relatively closer to the trailing edge thereof. to operate more effectively in low speed situations, such [0008] For example, the first position can have an an- as takeoff and landing, typically to decrease the stall gle ofattack that is in the range 0 - 10 degrees with respect speed of the wing. When the aircraft is properly airborne to the angle of attack of the wing and the second position and flying, the flaps can be retracted to increase the ef- can have an angle of attack that is greater than 10 de- ficiency of the wing and reduce drag. 15 grees with respect to the angle of attack of the wing, [0003] There are various types of trailing edge flap sys- optionally up to at least 35 degrees with respect to the tems. One type, known as a Fowler flap system, involves angle of attack of the wing. a two-stage movement of the flap as it is extended. In a [0009] The driven toothed pinion can be mounted for first stage, the flap extends mainly laterally from the trail- rotation about an axis substantially aligned with the span ing edge of the wing with little or no change of angle of 20 of the wing. attack with respect to the wing itself. The effect of this is [0010] Each rack can be a curved or arcuate rack such to extend the chord length (distance from the leading that operation of the pinion moves the connection to the edge of the wing to the trailing edge of the flap in the flap in both dimensions of the respective plane that in- direction of travel) of the whole wing and flap structure. cludes a chord of the wing. In this way the drive input In a second stage, the angle of attack of the flap with 25 from the pinion can be from a fixed position. The first and respect to the wing is increased, leading to an overall second struts can have different curved or arcuate racks. increase in the angle of attack of the wing and flap struc- In this way a single drive input can vary both the lateral ture. displacement of the flap from the wing and the angle of [0004] There have been a number of previous propos- attack of the flap. The rack on the first strut can have an als for flying car designs, i.e. vehicles that can be fully 30 equidistant distribution of teeth, and the rack on the sec- compliant with legal and practical requirements for both ond strut can have a non-equidistant distribution of teeth. road and flight use. Examples include the Terrafugia In this way the velocities of the connections of the struts Transition (WO 2007/114877) and the AeroMobil (WO to the flap can be made to vary. 2013/032409, WO 2016/057003, WO 2016/057004). [0011] Each strut can further comprise guide members [0005] The space available within the wings of these 35 that engage in guide tracks connected to the wing to con- vehicles for actuators and operating mechanisms is lim- strain the movement of the rack when the pinion is op- ited. In addition, it is usually necessary that operational erated. Each strut can have at least two guide members, controls between the body and the wing structure be ca- each guide member engaging in a respective guide track, pableof being disconnected for wing folding to take place. and each respective guide track defining a different path [0006] The invention aims to provide a wing and flap 40 of movement for its respective guide member. system that addresses at least some of these consider- [0012] The system can comprise at least two operating ations. mechanisms spaced along the span of the wing, the pin- [0007] A first aspect provides a wing and flap system ion of eachmechanism being defined on acommon shaft. for an aircraft, comprising: a wing; and a deployable flap Providing drive to the pinion of each operating mecha- connected to the wing, the flap being moveable between 45 nism can help avoid jamming due to distortion of com- a first position in which a trailing edge portion of the wing ponents. substantially overlaps the flap and the angle of incidence [0013] The pinion can be provided with a separable of the flap is substantially the same as the angle of inci- connection to be connectable to a motor located in a body dence of the wing, and a second position in which the of an aircraft to which the wing and flap system is con- trailing edge of the flap is behind the trailing edge of the 50 nected. wing and the angle of incidence of the flap is greater than [0014] Another aspect provides an aircraft comprising that of the wing, and an intermediate position between a convertible vehicle having a flight configuration and a the first and second positions, in which the trailing edge road use configuration, the aircraft comprising a body; of the flap is behind the trailing edge of the wing and the wheels for supporting, driving and steering the aircraft in angle of incidence of the flap is substantially the same 55 a road use configuration; and a pair of wings connected asthat ofthe wing; andfurther comprising a flapoperating to the body by a mounting structure, the wings being mov- mechanism for moving the flap between the first, second, able between an extended position in which the wings and intermediate positions, comprising: a driven toothed extend laterally from the body for a flight configuration,

2 3 EP 3 418 184 A1 4 and a folded position in which the wings extend along ture 10. The front wheels are both steerable and driven. the body from the mounting structure for a road use con- In addition, the front wheels 26 can be moved between figuration; wherein the wings comprise the wing and flap a retracted position (Figure 1) in which they are posi- system. tioned close to the body to reduce drag in flight, and an [0015] At least one motor can be located in the body 5 open position (Figure 2) in which they are positioned for that is controllable to move the flaps between the first, improved traction and control for road use. second, and intermediate positions when in the flight con- [0021] When the wings 16 are folded back to lie along figuration. the rear of the body 14, the trailing edge part of one wing [0016] The wing and flap system can be configured lies over the corresponding trailing edge part of the other such that movement from the extended position to the 10 wing. When folded in this way, the overall width of the folded position only takes place when the flaps are in the folded wings lies within the lateral extremities of the ve- first position. This can help avoid damage to the flaps hicle as defined, for example, by the wheels when ex- when the trailing edges of the wings are positioned close tended in the road use configuration. Furthermore, the to other structures when in the folded position. width of the folded arrangement is such that the wings fit [0017] Further variations can be made within the scope 15 between the upper parts of the tail vertical control sur- of the invention. faces 20, and the wing tips are adjacent the tail horizontal control surfaces 22. Figure 1 shows a front perspective view of a flying [0022] Figure 3 shows a schematic section through the car in a flight configuration; trailing edge region of the wing of the vehicle shown in Figure 2 shows a front perspective view of a flying 20 Figures 1 and 2 showing the relative positions of the wing car in a road use configuration; 16 and a trailing edge flap 30. Figure 3 shows a schematic view through the trailing [0023] The flap 30 is mounted on the underside of the edge regions of a wing of the flying car of Figures 1 trailing edge region of the wing 16. The flap 30 is move- and 2; able between a first position A and a second position C Figure 4 shows a partial view of an operating mech- 25 via a range of intermediate positions B. in the first position anism; A the flap 30 is substantially aligned with the wing 16, Figure 5 shows another view of an operating mech- the trailing edge 33 of the flap 30 lying under the trailing anism; edge 34 of the wing 16. In the intermediate positions B, Figures 6A - F show the relative positions of various the flap 30 is displaced rearwardly from the wing 16. The parts as aflap moves from afirst to a second position; 30 plane of the flap 30 is lowered with respect to that of the and wing 16, and the angle of attack of the flap is substantially Figure 7 shows a flap system with two operating similar to that of the wing. In the second position C, the mechanisms. flap 30 is further displaced behind and below the wing and has an angle of attack greater than that of the wing. [0018] Referring to Figures 1 and 2, an aircraft com- 35 [0024] Figure 4 shows a partial view of the operating prising a convertible vehicle (a flying car) is shown, in a mechanism used to move the flap 30 between positions flight configuration (Figure 1) and a road use configura- A, B, and C (parts are omitted for clarity). tion (Figure 2). The flying car comprises a body structure [0025] The operating mechanism comprises first and 10 providing a crew compartment 12 and housing a motor second struts 36, 38, extending between the wing 16 and (not shown) and propeller shaft (not shown) that extends 40 the flap 30. Each strut 36, 38 has a curved or arcuate from the motor to the rear 14 of the body structure 10, shape and is provided with a toothed rack 40, 42 on its where the propeller is mounted as is described below. concave surface. The distribution of teeth on the first rack Wings 16 for providing lift and control (via ailerons, not is substantially equidistant. The distribution of teeth on shown) are mounted at the top of the body 10 immediately the second rack is non-equidistant. First and second behind the crew compartment 12. The wings 16 are con- 45 guide members 44, 46 project from the side of the forward nected to a mounting structure (not shown) positioned part of the first strut 36 for engagement in guide tracks within the body 10 beneath a moveable cover 17. The (not shown) as is described below. Corresponding guide wings 16 can be moved between an extended position members are also provided on the second strut 38. for flight use (Figure 1), and a folded position for road [0026] The first strut 36 is connected near the leading use (Figure 2). In the folded position, the wings lie along 50 edge 32 of the flap 30 by means of a pivot connection the top of the body 10, the long axes of the wings lying 48. The second strut 38 is connected to the flap 30 by a substantially parallel to the long axis of the body 10. corresponding pivot connection 50 at a portion closer to [0019] A tail structure 18 is located at the rear of the the trailing edge 33 of the flap 30 than the first connection body 10, and includes vertical control surfaces 20 (fins 48. and rudders), and horizontal control surfaces 22 (tail55 [0027] A toothed pinion 52 is mounted in the wing 16 planes and elevators). Rear wheels 24 are provided at for rotation about an axis extending in the span direction the lower ends of the fins 20. of the wing. The pinion 52 engages the toothed racks 40, [0020] Front wheels 26 are mounted on the body struc- 42. Rotation of the pinion 52 acts on the toothed racks

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40, 42 and causes the struts 36, 38 to extend or retract At this point the struts 36, 38 are fully extended, the pinion together, moving the flap accordingly. being at the front end of each rack 40, 42. The main effect [0028] Figure 5 shows the operating mechanism from during this change of operation is to increase the angle the opposite side to that shown in Figure 4. of attack of the wing and flap combination. [0029] The second strut 38 has first and second guide 5 [0036] Reversing the drive of the pinion 52 reverses members 54, 56 corresponding to the first strut guide the sequence of movements and retracts the flap 30 into members 44, 46 shown in Figure 4. Each guide member the wing 16. 44, 46, 54, 56 engages in corresponding guide rails 58, [0037] Lines X and Y on Figure 3 show the trajectories 60, 62, 64 which define tracks constraining the range of of the first and second flap connections 48, 50 as the movement of each guide member 44, 46, 54, 56 to a10 struts 36, 38 extend.. In the initial phase of deployment respective predetermined path. The shape of each pair (Figures 6A - E), the trajectories are approximately linear of guide rails 58, 60, and 62, 64 is configured to provide and converge slightly, hence the lateral deployment with predetermined ranges of movement of the flap connec- only a small change in the angle of attack. In the final tions 48, 50 in both dimensions of a vertical plane con- phase of deployment (Figure 6 F), the trajectories diverge taining a chord of the wing as the struts 36, 38 extend or 15 relatively raising the first connection 48 and lowering the retract on operation of the pinion. The guide rails 58, 60, second connection 50, thus effecting the main change in 52, 54 are fixed to the wing structure (not shown). the angle of attack of the flap 30. [0030] Figures 6A-F show the relative positions of the [0038] Figure 7 shows the flap system with two oper- flap 30 and wing 16 as the operating mechanism moves ating mechanisms 80, 90. Each mechanism is substan- the flap 30 between the first position (Figure 6 A), inter- 20 tially as described in relation to Figures 4 - 6. Only the mediate positions (Figures 6B-E), and second position part of the flap 30 connected to each mechanism 80, 90 (Figure 6 F). is shown. [0031] Each of Figures 6A-F shows the relative posi- [0039] The pinion of each mechanism 80, 90, is mount- tions of the flap 30, first and second struts 36, 38, the ed on a common shaft 70 which is provided with a re- first and second flap connections 48, 50, and the posi- 25 leasable connection 72 by which the shaft 70 can be con- tions of the guide members 44, 46, 54, 56 in their respec- nected to a drive motor located in the aircraft body (not tive guide rails 58, 60, 62, 64. The wing 16 is shown in shown). By locating the connection 72 near the wing root, outline for reference. the drive can be connected or disconnected to allow wing [0032] Figure 6A shows the flap 30 in the first position folding. By providing an appropriate indexing system in (position A of Figure 3). The struts 36, 38 are in their most 30 the connection, the system can be configured such that retracted position with the pinion at the rear end of the the connection 72 can only be made or broken when the racks 40, 42. The guide members 44, 46, 54, 56 lie at flap is in the first position. This can help avoid damage the front ends of respective guide rails 58, 60, 62, 64. to the flap during wing folding. A universal joint or con- Driving the pinion 52 in an anti-clockwise direction caus- stant velocity joint can be provided in the shaft drive sys- es the struts to begin to extend and displace the flap 16. 35 tem to accommodate alignment issues when connecting [0033] Figure 6B shows the flap 30 in an early stage the systems. of deployment in an intermediate position (position B of [0040] By providing two substantially identical systems Figure 3). The shapes of the racks 40, 42, and of the and a common drive shaft, the possibility of jamming due guide rails 58, 60, 62, 64 mean that the flap 30 drops to distortion can be reduced. below the lower surface of the wing 16, and the trailing 40 [0041] Various changes can be made to the system edge 33 of the flap 30 extends behind the trailing edge disclosed above and in the claims. For example, where 34 of the wing 16. In this position, the angle of attack of two mechanisms are provided, one of the mechanisms the flap 30 is about 2 degrees greater than that of the can be passive, with no drive to the pinion, and the mech- wing 16. anism merely acts to control the movement of the flap [0034] Further operation of the mechanism continues 45 under the influence of the active mechanism. The exact to extend the struts 36, 38 and the flap moves laterally shapes of the guide rails, struts, and racks can be se- with a relatively small progressive increase in the angle lected to achieve the desired range of movements. Other of attack (Figure 6C: five degrees; Figure 6 D: eight de- changes are also possible. grees; Figure 6 E: 10 degrees) as the flap 30 moves through the range of intermediate positions. The main 50 effect during this stage of operation is to increase the Claims chord length of the wing and flap combination, with a relatively small change of angle of attack of the wing and 1. A wing and flap system for an aircraft, comprising: flap combination. [0035] In the final stage of movement, the racks 40, 55 a wing; and 42, and guide rails 58, 60, 62, 64 cause the first strut 36 a deployable flap connected to the wing, the flap to move more than the second strut 38, causing the angle being moveable between of attack to increase to about 35 degrees (Figure 6 F). a first position in which a trailing edge portion of

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the wing substantially overlaps the flap and the spective guide track defining a different path of angle of incidence of the flap is substantially the movement for its respective guide member. same as the angle of incidence of the wing, and a second position in which the trailing edge of 8. A system as claimed in any preceding claim, com- the flap is behind the trailing edge of the wing 5 prising at least two operating mechanisms spaced and the angle of incidence of the flap is greater along the span of the wing, the pinion of each mech- than that of the wing, and anism being defined on a common shaft. an intermediate position between the first and second positions, in which the trailing edge of 9. A system as claimed in any preceding claim, wherein the flap is behind the trailing edge of the wing 10 the pinion is provided with a separable connection and the angle of incidence of the flap is substan- to be connectable to a motor located in a body of an tially the same as that of the wing; aircraft to which the wing and flap system is connect- and further comprising a flap operating mecha- ed. nism for moving the flap between the first, second, and intermediate positions, comprising: 15 10. A system as claimed in any preceding claim, wherein the first position has an angle of attack that is in the a driven toothed pinion mounted in the wing; range 0 - 10 degrees with respect to the angle of and attack of the wing and the second position has an first and second struts, each substantially angle of attack that is greater than 10 degrees with aligned with a plane including a chord of the 20 respect to the angle of attack of the wing, optionally wing and extending between the pinion and up to at least 35 degrees with respect to the angle the flap, each strut having a toothed rack of attack of the wing. engaged with the toothed pinion such that operation of the pinion moves each strut in 11. An aircraft comprising a convertible vehicle having a direction substantially aligned with a plane 25 a flight configuration and a road use configuration, including a chord of the wing, the first strut the aircraft comprising a body; wheels for supporting, being connected to the flap relatively closer driving and steering the aircraft in a road use config- to the leading edge thereof, and the second uration; and a pair of wings connected to the body strut being connected to the flap relatively by a mounting structure, the wings being movable closer to the trailing edge thereof. 30 between an extended position in which the wings extend laterally from the body for a flight configura- 2. A system as claimed in claim 1, wherein the driven tion, and a folded position in which the wings extend toothed pinion is mounted for rotation about an axis along the body from the mounting structure for a road substantially aligned with the span of the wing. use configuration; wherein the wings comprise a 35 wing and flap system as claimed in any preceding 3. A system as claimed in claim 1 or 2, wherein each claim. rack is a curved or arcuate rack such that operation of the pinion moves the connection to the flap in both 12. An aircraft as claimed in claim 11, further comprising dimensions of the respective plane that includes a at least one motor located in the body that is control- chord of the wing. 40 lable to move the flaps between the first, second, and intermediate positions when in the flight config- 4. A system as claimed in claim 3, wherein the first and uration. second struts have different curved or arcuate racks. 13. An aircraft as claimed in claim 12, wherein the wing 5. A system as claimed in claim 4, wherein the rack on 45 and flap system is configured such that movement the first strut has an equidistant distribution of teeth, from the extended position to the folded position only and the rack on the second strut has a non-equidis- takes place when the flaps are in the first position. tant distribution of teeth.

6. A system as claimed in any preceding claim, wherein 50 each strut further comprises guide members that engage in guide tracks connected to the wing to con- strain the movement of the rack when the pinion is operated. 55 7. A system as claimed in claim 5, wherein each strut has at least two guide members, each guide member engaging in a respective guide track, and each re-

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REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• WO 2007114877 A [0004] • WO 2016057003 A [0004] • WO 2013032409 A [0004] • WO 2016057004 A [0004]