ARRANGEMENT FOR AVOIDING CLASHING BETWEEN AN ACTUATION ASSEMBLY AND AN UPPER COVER OF A FOLDING WING TIP

Abstract

An aircraft wing having a fixed wing and a wing tip device rotatable about a hinge at the tip of the fixed wing is disclosed. The wing further includes an actuation assembly for rotating the wing tip device about the hinge. The upper cover of the wing tip device includes an offset region extending inboard of the hinge axis, such that when the wing tip device is rotated to the ground configuration, the offset region extends into a space previously-occupied by the actuation assembly, but is outside the space occupied by the actuation assembly in the ground configuration.

Claims

1. An aircraft wing, the aircraft wing comprising a fixed wing and a wing tip device rotatable about a hinge axis of a hinge at the tip of the fixed wing between: (i) a flight configuration for use during flight and (ii) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that the span of the aircraft wing is reduced, wherein the wing further comprises an actuation assembly for rotating the wing tip device about the hinge, and wherein in the flight configuration the actuation assembly is in a first configuration occupying a first space, and in the ground configuration the actuation assembly is in a second configuration occupying a second space; wherein the upper cover of the wing tip device comprises an offset region extending inboard of the hinge axis, the offset region and the actuation assembly being arranged such that when the wing tip device is rotated to the ground configuration, the offset region extends into the first space, but is outside the second space.

2. A wing according to claim 1, wherein the actuation assembly comprises a rotary drive, the rotary drive being arranged to drive a moveable element in a curved path to move the wing tip device between the flight configuration and the ground configuration.

3. A wing according to claim 2, wherein the rotary drive comprises a pinion, and the moveable element comprises a curved rack for being driven along the curved path by rotation of the pinion.

4. A wing according to claim 2, wherein in the first configuration of the actuation assembly, the moveable element is within part of the first space, but in the second configuration of the actuation assembly the moveable element has been driven along the curved path to move it outside that part of the first space.

5. A wing according to claim 2, wherein the offset region of the upper cover is fixed relative to the moveable element of the actuation assembly.

6. A wing according to claim 1, wherein the hinge comprises two sets of interleaving lugs, each set of interleaving lugs comprising a plurality of lugs of the wing tip device interleaving a plurality of lugs on the fixed wing, the plurality of lugs on the wing tip device being rotatable about the hinge axis relative to the plurality of lugs on the fixed wing.

7. A wing according to claim 6, wherein the two sets of interleaving lugs are spaced apart along the hinge axis, and the offset region of the upper cover extends into the spacing between the two sets of lugs.

8. A wing according to claim 7, wherein the actuation assembly is located between the two sets of interleaving lugs.

9. A wing according to claim 8, wherein the offset region extends above the actuation assembly.

10. A folding wing tip arrangement for an aircraft wing, the arrangement comprising a fixed wing and a hinged wing tip device at the tip thereof, the wing tip device being configurable by a wing tip actuator between: (i) a flight configuration for use during flight and (ii) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that the span of the aircraft wing is reduced, wherein part of the upper cover of the wing tip device extends inboard of the hinge axis such that upon rotation from the flight configuration to the ground configuration, the part of the upper cover moves downwardly into a free-space within the volume of the wing, and wherein the wing tip actuator is configured such that movement of the actuator during actuation of the wing tip device from the flight configuration to the ground configuration exposes the free-space within the volume of the wing into which the upper cover extends.

Description

DESCRIPTION OF THE DRAWINGS

[0034] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

[0035] FIG. 1a shows a schematic view of an aircraft wing according to a first embodiment of the invention;

[0036] FIG. 1b shows a schematic view of an aircraft incorporating wings according to FIG. 1a;

[0037] FIG. 2a shows a close-up view of the hinge and the surrounding parts of the wing tip device and fixed wing of FIG. 1a, with some of the other surrounding structure removed for the sake of clarity;

[0038] FIG. 2b is a section view through A-A in FIG. 2a;

[0039] FIG. 2c is a close-up of the overlap region circled in FIG. 2b;

[0040] FIGS. 3a and 3b show the corresponding features of the wing in FIGS. 2a and 2b but with the wing tip partially moved from the flight configuration towards the ground configuration; and

[0041] FIGS. 4a and 4b show the corresponding features of the wing in FIGS. 2a and 2b but with the wing tip device in the ground configuration.

DETAILED DESCRIPTION

[0042] FIG. 1a shows a wing 10 comprising a wing tip device 12 and a fixed wing 14. The wing tip device 12 is configurable between: (i) a flight configuration for use during flight, as shown in FIG. 1b and (ii) a ground configuration for use during ground-based operations, as shown in FIG. 1a, in which ground configuration the wing tip device 12 is moved away from the flight configuration such that the span of the aircraft wing 10 is reduced.

[0043] The wing tip device 12 comprises an upper cover 26 connected to a wing tip root rib 28. The upper cover 26 forms the outer skin on the upper surface of the wing tip device 12.

[0044] The fixed wing 14 comprises an upper cover 30 connected to a tip rib 32. The upper cover 30 forms the outer skin on the upper surface of the fixed wing 14.

[0045] FIGS. 2a to 4b show part of the wing 10 in the first embodiment of the invention, and reference will now be made to these Figures.

[0046] FIGS. 2a, 3a and 4a show close-up views of the hinge and of the surrounding parts of the wing tip device 12 and fixed wing 14. The leading and trailing edge structures have been removed for the sake of clarity. It will be appreciated that these leading and trailing edge structures extend fore and aft of the parts of the wing shown in FIGS. 2a-4a.

[0047] Referring first to FIG. 2a, the wing 10 comprises the wing tip device 12 and the fixed wing 1. The wing tip device 12 is hinged to the fixed wing about a hinge 16 having a hinge axis 18. The hinge 16 comprises a series of interleaving lugs 20 on the root of the wing tip device 12 and the tip of the fixed wing. The lugs 20 have apertures 22 through which a hinge pin (not shown) extends (the hinge pin being coaxial with the hinge axis 18). The interleaving lugs 20 are provided in two sets, with a space between for accommodating an actuator mechanism (described in more detail below).

[0048] The interleaving lugs 20 also comprise a series of lower apertures 24 for receiving locking pins (not shown) to hold the wing tip in the flight configuration. The exact nature of the locking arrangement for holding the wing tip device in the flight configuration is not relevant to the present invention and is not described in detail herein.

[0049] The majority of the upper cover 26 of the wing tip device extends up to the edges of the hinge lugs 20. However, the upper cover 26 also comprises an offset region 34 protruding further inboard. As most clearly shown in FIG. 2b, this offset region extends inboard of the hinge axis 18.

[0050] In the flight configuration, the cover 26 of the wing tip device and the cover 30 of the fixed wing a substantially flush with each other and form a smooth aerodynamic surface. An edge 30a of the upper cover 30 on the fixed wing (illustrated by a long rectangular panel in FIG. 2a) overlaps the distal free end 34a of the offset region 34 of the wing tip upper cover 26 (shown circled in FIG. 2b and in close up in FIG. 2c).

[0051] As illustrated in FIG. 2c, the distal free end 34a of the offset region comprises a sealing support structure 35 extends along the overlap region and supporting a compression P-seal 35a that is compressed (in the flight configuration) by the overlapping end 30a of the fixed wing.

[0052] The wing 10 comprises an actuation assembly 11 comprising a geared rotary actuator GRA (not fully visible in the Figures) and a curved rack 40. The curved rack 40 comprises a series of teeth spaced along the curved surface, but these are not illustrated in the Figures. The GRA has an output shaft onto which a pinion gear 38 is mounted. The pinion gear 38 is coupled, via a secondary gear 39, to mesh with the teeth of the curved rack 40. The curved rack 40 includes a support structure 42 which is fixedly attached to a root of the wing tip device 12 via a pair of lugs 44 (only one of which is visible in FIG. 2b).

[0053] The GRA is arranged to drive the rack 40 in a curved path to move the wing tip device 12 between the flight configuration (FIG. 2a/2b) and the ground configuration (FIG. 4a/4b). That movement will now be described with reference to FIGS. 3a to 4b.

[0054] FIGS. 3a and 3b show the wing tip partially moved from the flight configuration towards the ground configuration. The GRA has rotated the pinion 38 such that the rack is rotated outboard, thereby moving the wing tip device 12 such that it rotates about the hinge axis 18.

[0055] The offset region 34 of the upper cover 26 of the wing tip device is fixed relative to the rack 40 of the actuation assembly. It therefore moves as part of the wing tip device.

[0056] Since the offset region extends inboard of the hinge axis 18, rotation of the wing tip device about that axis causes the offset region to move downwardly into the wing box of the wing 10. This might be expected to cause a clash with internal structure of the wing. However, in the first embodiment of the invention, the actuation assembly 11 also moves to a different configuration as the wing tip device is rotated. More specifically, the rack 40 rotates about the axis 18, freeing up space that the rack was previously occupying. In the first embodiment of the invention, the offset region 34 of the upper cover 26 moves into this freed up space thereby avoiding a clash.

[0057] FIGS. 4a and 4b show the wing tip device 12 in the ground configuration, and reference will now be made to these Figures. In the ground configuration, the rack 40 has rotated fully and the rack occupies a different space (i.e. volume in the wing) compared to the space it occupied when the wing tip device was in the flight configuration. The offset region 34 of the upper cover extends into the wing, but it extends into the space previously occupied by the rack (i.e. the space the rack occupied in the flight configuration), but is outside the space occupied by the rack in the ground configuration.

[0058] Such an arrangement is advantageous in that it enables the wing tip device 12 to move between the flight and ground configurations without needing to provide a separate moveable panel, or otherwise potentially complex mechanism. Embodiments of the present invention may therefore be relatively simple and low maintenance.

[0059] The embodiment in FIGS. 2a to 4b also provides advantages during return of the wing tip device 12 from the ground configuration to the flight configuration: The return movement of the wing tip device 12 to the flight configuration is effected by the reverse rotation of the pinion 38, and hence the reverse movement of the rack 40 along its curved path. By virtue of the overlap of the fixed wing cover 30 with the distal end 34a of the offset region 34, and effective compression seal may be maintained.

[0060] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein.

[0061] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.