GB2402914A - Deployment system for a moveable wing surface - Google Patents

Abstract

A deployment system for deploying a moveable wing surface (22) from a main wing section (8). The deployment system includes a plurality of swing arm assemblies (24,26) connecting the moveable wing surface (22) to the main wing section (8) and a drive means for deploying and retracting the moveable wing surface (22), wherein at least one of the swing arm assemblies (24,26) includes a swing arm (28) pivotably connected to the main wing (8) and a connector mechanism (34) for connecting the movable wing surface (22) to the swing arm (28). The connector mechanism (34) includes a first joint (36) having at least first and second rotational degrees of freedom and a second joint (40) having at least first and second rotational degrees of freedom and at least first and second translational degrees of freedom, said connector mechanism (34) being arranged to provide, in use, rotation of the moveable wing surface (22) about its longitudinal axis during deployment of the moveable wing surface (22), and allowing relative movement between the moveable wing surface (22) and the main wing section (8) due to thermal expansion and contraction of the movable wing surface (22).

Description

Deployment System For a Aloveable wing Surface Thepresent invention

relates to a deployment system for deploying a moveable wing surface such as a slat or flap, froth a main wing section.

Various mechanisms leave been proposed for deploying slats and flaps on aircraft wings, s including paired track systems, Kruger flap systems and swing aria systems The present invention relates to a swing any system, for example of the general type described in lntellationa] patent application No: PC f/NZ95/00096.

It has been shown to be bcneLcial in deployment systems o have an a' r ai, geinenl that achieves a contigrui-ation during takeoff wherein the slat is deployed and rotated r: dative t<, the main to living to a first exl:ent such that there is no gap between the deployed slat: en 1 fit leading edge of the main wing, and a configuration during landing wherein the slat is deployed and rotated À to a second, greater, extent such that a slot is fowled between the trailing edge of the slat and the leading edge of the wing (for example, see US Patent 4,399,970). Most wings taper from À À root to tip, and variable camber- devices should mimic this taper to give full benefits along the i 5 length of the wing. À

. In prior art swing ar m slat deployment systems such as that described in 1': i'1!/,95/00096, À À.: normally only one of the swing arms is driven, the undriven swing arm simply following the movement of the driven arm owing to its connection to that arm through he flat. 'his avoids mechanical stresses in the slats and the swing arms which might otherv ise occur, for example when the slat and the wing experience different degrees of therrral expansion during flight. However, the arrangement suffers from the disadvantage that the undriven arm is not closely controlled, which can result in a step being left between blue slat and the main wing section when the slat is in a stowed position.

However, if both swing arms are driven, the mechanism becomes susceptible to mechanical stress and could also under certain circumstances become jammed With con swing arm slightly in front of the line that passes through the pivot joints and the other saving arm slightly behind that line. (his risk may he heightened when. for example, the slat and the wing experience different amounts of thermal expansion, or when the mechanical components in the slat mechanism are worn or do not meet required manufacturing tolerances. Locking of the swing arms could prevent the slat from deploying fully or cause it to become stuck in a patially-deployed position with potentially dangerous results.

s A slat deployment system is described in GB 2362363 that addresses some of these issues.

(hat system includes a slat that is connected to a main wing by first and second am assemblies. Each aim assembly includes a swing am1 that is pivotally attached to the main wing and upper and lower connector assemblies connecting the slat to the swing akin. The first and seconded and assemblies are very similar: however, they dither in that the upper joint of the lo second aim assembly includes a lost motion mechanism. The slat is deployed fiom the main wing section by a drive system that drives both the first and second aim assemblies. The lost I motion mechanism included in the second aim assembly reduces the potential forjammirlg by compensating f'or thermal expansion and contraction of the slat without transmitting stresses!

to the main wing...DTD: as The deployment system described in GB 2362363 provides a way of Electing the desired slat À configurations for take off and landing described above and overcoming the problems associated with systems where only one of the aim assemblies is driven. In particular, it is the arrangement of the swing arms that defines the extent of deployment of the slat and the À. . interaction:'fthe upper and lower connector assemblies that causes the slat to rotate and hcoce I change its angle of attack. However, that system is considered to be overly complex and lack mechanical robustness.

In mcchailical systems used on aircraft simplicity is paramount. For example, with deployment systems having multiple aims with many bearings, rigging of the system is difficult, initial costs are high, maintenance is expensive, and the possibility of system failure increases. With 2s all deployment systems it is necessary to make sure that any linkage mechanism does not get into a kinematic arrangement where it becomes locked. Deployment systems also need to be rigid in all conditions to prevent flutter and rapid wear of joints, and they need to handle loads efficiently and relay then1 to the main wing structure.

Accordingly it is an object of the present invention to provide an alternative deployment system to those currently known that mitigates at least some of the above-mentioned problems.

According to a first aspect of the invention there is provided a deployment system for deploying a moveable wing surface fiom a main wing section, the deployment system including a plurality of swing akin assemblies connecting the moveable wing surface to the main wing section and a drive means for deploying and retracting the moveable wing surface, wherein at least one of the swing and assemblies includes a swing arm pivotably connected to the main wing and a connector mechanism for connecting the movable wing surface to the swing aim, the connector mechanism including a first joint having at least first and second rotational degrees of fi-eedom and a second joint having at least first and second rotational degrees off fi-eedom and at least first and second translational degrees of freedom, said connectormec]1anism beingaiTangedto provide, in use, rotation ofthemoveablewing surface about its longitudinal axis during deployment of the moveable wing surfaces and allowing relative movement between the moveable wing surface and the main wing due to thermal expansion and contraction of the movable wing surface. À:. Àe-

Rotation of the moveable wing surface about its longitudinal axis is controlled by the

A

interaction of the first and second joints as the moveable wing is deployed and retracted.

alp. Relative movement between the moveable wing surface and the swing akin due to thermal . expansion of the movable living surface is facilitated by the second translational degree of fi eedom. The invention provides a more simplified and mechanically more robust À À À. configuration than other prior aft systems, such as the system described in GB 2362363. À À À Àe

Preferably the second joint is arranged such that the first translational degree of fi-eedom is in a direction that is substantially perpendicular to a longitudinal axis of the swing akin and is in the plane of the swing arm.

Advantageously the second joint is an-anged to perform sliding movement r e]ative to the swing am1 in the direction of the first translational degree of freedom to move the moveable wing surface relative to the main wing.

Advantageously the second joint is arranged such that the second translational degree of fieedom is in a direction that is substantially parallel to the longitudinal axis of the moveable wing surface. Preferably the second joint is arranged to perform free sliding movement in the direction of the second translational degree of freedom that allows, in use, lost Motion between the movable wing surface and the main wing.

A deployment system according to any one of the preceding claims \vLerein the second joint is alTanged such that the first rotational degree of freedom is about an axis that is substantially perpendicular to the] ongitudina] axis of the swing am1 and is in the plane of the swing any.

s Advantageously the second joint is arranged SUC]1 that the second rotational degree of fi eedom is about an axis that is substantia]]y paia] ]el to the]ongitudina] axis Of the moveable wing surface.

Advantageously the first joint is arranged such that the first rotational degree of freedom is about an axis in a direction substantially pependicu] ar to the longitudinal axis of the swing o and and is in the plane of the swing aim, and the second rotational degree of fi-eedomr is about an axis substantia]]y parallel to the longitudinal axis of the moveah]e wing surface. À:-

Advantageously the second joint is a sliding sp]lel-ica] jOiilt. À.e

Preferably the deployment system includes a second swing and assembly pivotab]y connected to the main wing and a connector mechanism for connecting the movable wing surface to the À:. Is swing ann, the connector mec]lanisll1 including a first joint having at least first and second rotations.] degrees of fi-eedom and at least a first translational degree of fi eedom and a second À joint having at least first and second rotational degrees of freedom and at least first and second À À. trans]ationa] degrees of freedom. Preferably the first joint is ananged such that the first translational degree of fi eedom is in a direction that is substantia]]y para]le] to the lorigitudina] so axis of the moveable wing surface. The first joint is arranged to perform Tee sliding movement in the direction of the first translational degree of freedom that allows, in use, lost motion between the movable wing surface and the main wing section The moveab]e wing surface and the main wing are arranged SUC]1 that a part of the moveable wing surface remains substantia]]y in contact with a part of the mail1 wing section when the 2s moveab]e wing surface is positioned between a fully retracted position and a partially deployed position and a slot is created between the main \ving and the moveab]e wing surf-ace when the moveab]e living surface is positioned between the partially deployed position and a Ally deployed pOSitiOIl.

The moveable wing surface, aim assemblies and the main wing section arc arranged such that the size and shape of the slot is controlled. Preferably the moveable wing surface, awn assemblies and the main wing are arranged such that the slot is tapered. Typically the width of the slot is wider town ds the root of the Wing, with the slot tapering to a naToNver width towards the tip of the wing Preferably the distance between the noveab]e wing surface and the main wing is proportional to the chord of the wing. During nominal Light conditions the moveable wing surface is retracted and fonns the leading edge of the main wing. The deployment system allows the moveable wing surface to be deployed away from the main wing and to change its angle of attack such that the moveable wing surface can adopt an lo extended and rotated condition to alter the camber of the wing. This changes the lift / drag characteristics of the wing to make it more suitable for performing particular manoeuvres.

For example the moveable wing surface can be deployed from the main wing and alter its angle of attack without creating a gap between moveable wing and the main wing. This first condition is typically used during takeoff. The moveable wing surface can also be deployed À .e is in an extended and rotated condition with a gap between moveable wing and tile main wing.

:. .: This second condition is typically used during landing. The first and second conditions are À:. achieved by the arm assemblies controllably deploying and rotating the moveable wing e surface. À À- À.

À.: A main wing typically includes a plurality of moveable wing surfaces distributed along the leading edge of the main wing, for example a wing may include between two and six moveable wing surfaces, but preferably includes three. Typically the swing arms rotate through an angle of between 80 and 120 degrees to deploy the moveable wing surface from a retracted position to a Lilly deployed position.

Advantageously the dcp]oyment system includes a p]ura]ity of moveable wing surfaces 2: distributed along the main wing section, wherein each movable wing section is connected to a plurality of swing akin assemblies and the drive means includes a rnec]lanism linking at least one swing awn assembly associated with each moveable wing surface such that, in use, the drive means deploys the moveable wing surfaces substantially simultaneously. Preferably the drive means includes a hydraulic drive system that actuates the awls assen-b]ies substantially synchronous]y.

The deployillcnt system for deploying a moveab]c wing surface fi om a main Wing section may he aTanged to include a plurality of sNving akin assemblies connecting the moveable wing surface to the main wing section and a drive means for deploying and retracting the moveable wing surface, wherein at least one ofthc SNVing arm assemblies includes a swing aim pivotably connected to the main wing and a connector mechanism for connecting the movable wing surface to the sNving any, the connector mechanism including a. first joint comprising a universal joint and a first mounting that attaches the first joint to the moveable wing surface, a second joint having a first shaft arranged substantially parallel to the moveable wing surface, o second and third shafts that ar e axially aligned and mounted in bores in the swing aria and that are arranged to pivot and slide within their respective bores said second and third shafts are al-anged substantially perpendicular to the longitudinal axis of the swing any, a support À .. member attaching the first. shaft to the second and third shafts, and a second mounting that attaches the movable wing surface to the first shaft, wherein the second mounting, the support member and the first shaft. are an-anged for relative rotational and translational movement À Alp. between the second mounting and the first shaft, the translational movement allowing lost À À À motion between the moveab] e wing SCCtiOil and the main wing due to thermal expansion and contraction of the movable living surface, and the interaction between the first and second À À joints causes, in use, r oration of the moveable wing surface about its longitudinal axis during Àe À(! deployment of'the moveable wing surface.

In one embodiment the support member is fixcd]y attached to the first, second and third shafts and the second mounting is arranged for pivoting movement about and sliding movement along the first shaft. In another embodiment the support member is fixedly attached to the second and third shafts and the first shaft is arranged for pivoting movement and for sliding movement relative to the support member.

I'he deployment system for deploying a moveable wing surface fi-om a main wing section.

may alternatively be arranged to include a p]ura]ity of swing any assemblies connecting the moveable wing surface to the main wing section and a drive means for deploying and retracting tile moveable wing surface, wherein at least one of the swing aTln assemblies includes a swing am1 pivotably connected to the main wing and a connector mechanism for connecting thc movable wing surface to the swing ann, the connector mecllanisn including a first joint comprising a universal joint and a second joint comprising a sliding spherical joint, NvLerein the second joint alloNvs lost motion between the moveable wing section and the main wing due to thennal expansion and contraction of the movable wing surface, and the interaction between the first and second joints causes, in use, rotation of the moveable wing surface about its longitudinal axis during deployment of the moveable wing surface.

According to a second aspect of the invention there is provided an aircraft including a deployment system substantially as described above.

An embodiment oftheprcsent invention will now tee described, byway of example only, wit h 0 reference to the accompanying drawings in W]li cl1 like references indi cate eq uival ent 1-eat s ares, where) a: Figure 1 is a diagrammatic plan view of a wing with three slats at the leading edge separated by an engine pylon; Figure 2 is a sectional side view of a wing leading edge showing a swing aim asse Ably :. .Is in a. retracted position; Àe Figure 3 is a sectional side view showing a swing aim assembly in a semi-depJoyed À À . . a, position; À Figure 4 is a sectional side view showing a swing any assembly in a fully deplo>-.d position; Figure 5 is a Front view of a wing leading edge with a swing arm assembly in a r etracted position; Figure 6 is a Font view of a wing leading edge with a swing aim in a semi-deployed position; Figure 7 is a Front view of a wing leading edge with a swing am in a fully deployed 2s position; Figure 8 is a detail Vienna of a sliding joint; Figure 9 is a side view of a second swing am1 assembly; c Figure 10 is a plan view of three swing aims interconnected by actuation struts; and Figure 11 is a detail view of a second sliding joint.

Figure I shows part of an aircraft 2 having a fuselage 4 with a centre line 6. In the drawing, only the port wing is shown: this includes a main wing section 8 having a leading edge 10, a trailing Bilge 12, a wing tip 14 and a root 16. The wing is tapered, the chord decreasing fi om the root 16 to the tip 14. An engine 18 is attached to the underside of the main wing section i 8 by -means of a pylon 20.

A pluralityofs]ats 22 is attached to theleading edge ofthe wing. In the example shown in the drawing, there are three slats, an inner slat 22a, a middle slat 22b and an outer slat 22c. Each i slat '?2 is attacled to the leading edge I O of tile wing by means of first and second swirly and asse-ii,b]ies 24,26. Each slat has at least two swing aml assemblies, for example tile Antler slat 22a has one first Swing and assembly 24 and three second swing aim assemblies 26. Àe

The first swing amp assembly 24 is shown in more detail in Figures 2,3 and 4. The assembly 24 includes a swing am 28 that is attached at one end by means of a first pivot joint 3() to a ts structural member 32 within the leading edge envelope 10 of the main wing section 8. The À:. pivot axis oftlle firstpivot joint30 is inclined f'orwardsre]ativeto the vertical axis ofthellain wing section 8 so that as the slat 22 is dcpkyed, it is translated forwards and downwards relative to the leading edge of the wing 1 O. The swing am1 28 has a longitudinal axis that [ À À extends perpendicular to the pivot axis of the first pivot joint 30 and lies in the plane of th swing arm 28.

The swing, aria 28 is connected at its other end to the slat 22 by means of a connector mechanism 34. The connector mechanism 34 includes a first joint 36 and a second joint 40.

The first joint 36 is a universal joint that provides two rotational degrees of freedom and is mounted between a first pair of fingers 38, comprising upper and lower f ngers 38a,38b, that protrude Tom the sinning and 28. The first joint 36 allows rotation about a first axis that is substantially perpendicular to the longitudinal axis of the swing any 28 and lies iri the plane of tile staling any, and a second axis that is substantially perpendicular to the first axis and parallel to the longitudinal axis of the slat 22.

The connector mechanism 34 also includes a second joint 40, comprising a sliding universal joint that is arranged to allow first and second rotational degrees of fi-eedom about first and second axes of rotatiol1 respectively and first and second b-alls]atiollal degrees of fi-eedom along the first and second axes of rotatiol1. The first axis of rotation is substantially perpendicular to the longitudinal axis ofthe swing anal 28 and lies in the plane of'the swing any 28, and the second axis is substantially perpendicular to the first axis and parallel to the longitudinal axis of the slat 22. The first axes of rotation of the first and second joints are substantia]]y parallel to one another and likewise the second axes of rotation are also i substantially parallel to one another.

The first axes of rotation of the first joint 36 and the second joint 40 may a]terllatively be arranged substantially pai-allel to the axis of the pivot joint 30. i Figure 8 shows an enlarged view of the second joint 40 and its mounting arrangement. The second joint 40 is mounted on the swing elm 28 behveen a second pair of fingers 42, compri sing upper and lower fingers 42a,42h, located towards one end of the elm 28 below and substantially parallel to the first pair of fingers 38. The upper and lower fingers 42a,42b each have a through hole 44. The second pair of fingers 42 is shorter than the first pair of fingers >beet À À 3 8. The difference in length between the first and second pail s of fingers 3 8,42 means that the effective radius oft]1e swing al1n 28, that is the distance between the first pivot point 30 and the first pivot axes of the first and second joints rcspective]y, is greater for the first joint 36 À Àe than f'->r the second joint 40. Thi s difference in effective radi us of the swing and 28 for the fi rst [ À À.

and second joints 36,40 causes the slat 22 to rotate as it is deployed.

The slat 22 is attached to the second joint 40 via a mounting, 46 that includes two alms 48 each having a through hole 50. The second jOil1t 40 includes a first shaft 52 and a SUppOlt Inelnber 54 having upper and dower shafts 56a,56b attached thereto and a through hole 58. The first shaft 52 extends through the hole 58 in the support member 54, through the holes 50 in the slat mounting alms 48, and is fiend relative to the SUppOlt member 54. The arrangement a]]ows the SUppOlt mounting 46 to rotate about and fi-ee]y slide along the first shaft 52, thus pennitting the second rotational andtransiationa] degrees offi-eedom. The s]idingmovcn1entbetween the slat mounting 46 and the first shaft 52 allows for limited moNci1ent of the slat 22 relative to the swing elm 28 substantially in the axial direction of the slat 22, svl1icl1 serves as a lost motion mechanism between the slat 22 and SNVing aim 28. 'he lost inotion mecl1anisn compensates for thennal expansion and contraction of the slat 22 during flight, without transferring stresses to the main wing section 8. The lost motion mechanism also compensates for wear in the joints and for manufacturing tolerances in the components of the system. The mec]lanisn: prevents the slat 22 fiord jamming when, for example, the staling alms 24,26 are aligned.

A]ternativc]y, the slat mounting alms 48 can be fiecd to the first shaft 52 and the first shaft 52 can be arranged such that it can r otate and move trans]ationally relative to the support member 54 in hole 58. As the slat 22 undergoes thermal expansion the first shaft 52 can provide lost motion between the slat 22 and the swing and 28 by moving fi-ee]y trans]ational]y r e]ative tt' 0 i-he support member 54. This provides an a]temative arrangement for providing the second rotational and b^ans]ationa] degrees of fi-eedom.

The upper and lower shafts 56a,56b are fixed to the support membci- 54 and each extends through one ofthe holes 44 in the upper and dower fingers 42a,42b respectively. lThe upper and À . lower shafts 56a,56b are al-anged such that they can rotate relative to the upper and Mover !5 fingers 42a,42b and can slide through holes 44, permitting the first rotational and trans]ationa] À À degrees of freedom.

The second joint 4() described thus has four degrees of freedom. T ho sliding movement of the À, . . upper and] rower shafts 56a,56b the ough the upper and]owcr fingers 42a,42b a] 1ONVS fair]i mited À I, À movement ofthe slat 22 relative to the Swing and 28 in a direction substantia]]y perpendicular to the swing ann 28.

The interaction between the first and second joints 36,40 controls rotation of the slat 22 though an angle in the range 22 to 32 degrees and pi-efcrab]y approximately 27 degrees, and therefore determines its angle of attack. Since the second axes of rotation of the first and second joints 36,40 are offset, rotation ofthe slat 22 about the second axes causes translational movement of the suppoit member 54 along the first axis of rotation of the second joint 40.

The second swing aim assembly 26 is s]ight]y shorter thai1 the first swing am1 assembly 24 so that when the slat 22 is deployed, the separation betNvecn the slat 22 and the wing leading edge 10 is s]ight]y] argei at the inner end of the slat 22(toNvards the r cot ofthe main wing 16) than it is at the outer end of the slat 22 (towards the tip of the main wing 14). I his provides an idea] configuration, wherein the distance between the slat 22 and the wing 8 is propotiona] to tle chord ofthe wing at that point. When the swing aim assemblies 24,26 are deployed they typica]]y rotate through approximately the same angle which means the translation of'the first joints wild vary along the length of the wing. 'loo accor,lmodate this a1-angemcnt the second s swing aria assembly 26 includes a modified first joint 36a that includes a lost motion me-charism (see Figure 9). That is, the first joint 36a includes fast and second rotational degrees of fi-eedoill (as the first joint 36 in the first Swing am1 assembly 24) but also includes a first translational degree of freedom in a direction that is substantia]]y parallc] to the ]ongitudina] axis ofthe slat 22. The first joint 36a includes a shaft 36b, and is connected to the It) slat 22. via a mounting attached to the shaft 36b. The shaft 36h is arranged for Tee sliding movement in a direction su'bstantia]]y paral l el to the l ongitudinal axis elf the slat ?.2 and the '. fist motion mechanism operates sirnilar]y to the lost motion mechanism included in the second joint 4() Tile lost motion mechanism reduces the amount of stress transmitted to the main w'ng . : section 8 because of the relative positions of the first joints 36,36a when the first and second À as arm assemblies 24,26 are deployed. The lost motion mechanism also reduces the amount of stress transmitted to the main wing section due to themla] expansion and contraction of the me À, À moveab]e wing surface. :e

Tc; achieve tile idea] configuration of slat 22 dep]oymcnt for tapered wings handing a phralit)' À.... ors]ats 22a,22h,22c, the length ofthe swing aim assemblies 24,26 used decreases the t'rtlei À Ah array they are located from the root 16 of the wing, i.e. the longest swing aim assembly 24 used is located closest to the root 16 of the win:, and the shortest is located towards tile tip 14 of the wing.

In other aspects the second swing arm assembly 26 is similar to the first swing akin assembly 24.

?.5 The first swing arm assembly 24 also includes a drive mechanistic (not shown) for driving tile t'irst swing aria assembly 24 forrotation about the first pivot joint 32 fi-om a retracted position to a f'ul]y deployed position.

To deploy the slat 22, the drive mechanism for the first swing aim asseinbly 24 is actuated, ; causing the first Swills arm 28 to rotate through an angle of approximately 90 degrees from the retracted position shown in Figures ? and 5 in \]liC]1 it is approximately para]le] to the -] 2 leading edge of the living 10 to the deployed position shown in Figures 4 and 7 in which the am1 is approximatc]y perpendiculal- to the 1eadillg edge ofthe wing 10. The second swing elm assembly 26 is actuated at the same time as the first SWillg am1 assembly 24 by a system of linkages connecting the am1 assemblies 24,26 together (see the intercollnectiol1 system described below).

Opel ation of the first arm assembly 24 only will now be described for the purposes of clarity.

The pivot axis of the first pivot joints 30 of the first elm assembly 24 is inclined forwards so that as the slat 22 is deployed, it is b-ans]ated Collards and downwards relative to the leading edge of the wing 10. The slat 22 is further caused to rotate about its longitudinal axis by the 0 interaction of the first joint 36 and the second joint 40. When the slat 22 is in the retracted position the SUppOlt melmbel- 54 is located at its minimull1 height position towards the lower finger 42b. As the slat 22 is deployed the SUppOlt membcl- 54 moves towards the upper finger 42a reaching its maximum height position when the slat 22 is fully deployed. This riovemellt Àe e.

causes the slat 22 to rotate relative to the main living section 8 and therefore change its angle À.1.s of attack. The slat 22 can rotate Ol tiltabout its longitudinal axis between the approximate: positions shown in Figures 2 and 4. The second alien assembly 26 operates in a complemcntal-y Àe À À way to the first arm assembly 24 to achieve deployment of the slat 22. À:.

In order to ensure the system deploys symmetrically over both wings an interconnection: À A system is employed. The interconnection system connects the slats 22a,22b,22c SUCK that they À.:o all deploy substantially at the same time. One such system is illustrated in Figure 10. The interconnectiol1 system uses a strut 60 pivotally connected to the Swing elm assemblies 24,26 of a particular slat 22 (a first slat) to provide a connection between the first saving elm assembly 24 and the second swing am1 assembly 26. A second Stl ut 62 is used to connect the second and assembly 26 of the first slat to the first any assembly 24 of an adjacent slat. The lost motion mechanism in the first joint 36a ofthe second swing aim assembly 26 ensures that thermal differences between the slat 22 and the main wing 8 do not contribute to poor setting of tile slats 22 nor produce stress in the mechanism. By carefully positioning tile pivot joints on the swing and assemblies 24,26 it is possible to improve the mechanical advantage of the interconnection system, such that lower strut forces arc required to deploy and reb-act the system, thus ensuring minimal system weight. Such an advantageous set-up is shown in Figure 10 where the strut 60 stays at a maximum distance from the axis of rotation at a]] times, thus ensuring maximum available torque for minimal force.

Anotller interconnection system (not shown) connects the second Swing aim assembly 26 for a first slat to the first swing am assembly 24 of a second slat 22, for example the inner slat 22a to the middle slat 22b. No strut is used to connect the ann assemblies for a particular slat since connection between the any assemblies is provided by the slat structure itself.

The second joint 4() is not limited to the particular ai1-angemcnts described above but can adopt any suitable arrangement that provides the desired degrees of fi-eed'm. For example, in a second embodiment of the invention the second joints 40 in the first and second am 0 assemblies 24,26 are r eplaced by conventional sliding spherical joints I 4() that attach the slat to the swing alms (see Figure I 1). In other respects, the second cmbodiilleni- is similar to the first embodiment The sliding spherical joint 140 has first and second rotational degrees of freedom and first and second translational degrees of fi-eedom. It is mounted on the swing akin between a pair of is fingers 142, comprising upper and lower fingers 142a,]42b. The upper and lower fingers ] 42a, 142b each have a through hole 144. The sliding spherical joint 14() includes a bracket 146 having a T-shaped slot 148 that defines a bearing surface, and a bearing member 150. "-'he bracket 146 is attached to the slat. The bearing member 150 includes a part that is À À.

complementary to the T-shaped slot 148. 'Idle complementary paint is located within the slot 148 and can slide freely along it, and defines the second translational degree of fi-eedom. The free sliding movement of the bearing member] 50 in the slot]48 acts as a lost motioned mechanism allowing relative movement between the slat and the main wing section in a direction substantially parallel to the longitudinal axis of the slat to compensate for thennal expansion aIId contraction of the slat during flight, without transfer-ing stresses to the main Wi'lg, section 8.

The bearin,, member 150 houses a spherical member 152. The spherical member 152 has a through hole 154. A shaft 156 is located within the hole] 54 and is arranged to extend through holes 144 ill the fingers 142a, ] 42b. 'I'he spherical member 152 can move rotationally relatiN e to the bearing member 150 but 'lOt: translationally. The spherical member 152 ales the bearing, member 15() to rotate about the shaft 156 and to tilt relative to the shaft 156. 'l'hc -1 4 spherical member 152 can also slide along the shaft 156. The relative movement between the shaft]46 and the hearing member 150 permits the first and second rotational degrees of fi eedom and the first translational degree of fi eedom in the sliding spherical joint 140.

Similarly to the first embodiment of the invention, deployment of the slat is controlled by the interaction of the first joint 36, and the sliding spherical joint 140. I he arrangement of the second embodiment provides a light, stiff and relatively simple mechanical joint.

The swing akin system may be used for deploying slats or flaps and in the above description references to,lat dep]oyinent systems are intended to include flap deployment systems, and vice versa. À. Abbe Àe À. >-e À À:e À À À À. À. À Àe -1 5

Claims (1)

1. Claims 1 A deployment system for deploying a moveable wing surface from a

   mails wing section, the deployment system including a plurality of swing elm assemblies connecting the moveable wing surface to the main wing section and a drive means for deploying and retracting the movcab]e wing surface, wheTcin at least one of the sNving am1 assemblies includes a swing am1 pivotably connected to the main wing and a connector nechanisin for ConneCtiTlg the IllO\table WiTlg surface to the SNViTlg ann, the connector mechanists including a first joint having at least first and second rotational degrees of fi eedom and a second joint having at least first and second rotational degrees of fi eedon1 and at least first and second translational degrees of -freedoTn, said connector mechanism being arranged to provide, in use, rotatioTI of the moveablc wing surface about its longitudinal axis during deployment c f the no -veablc wing surface, and allowing r elative movement between the moveable wing surface and the maiT1 wing due to theTmal expansion and COntTactiOn of the movable wing surface.

   2 A deployment system according to claim 1, herein the second joint is arranged such a 5 that the first translational degree of freedom i s in a direction that is substanti ally perpendi culaT to a longitudinal axis of the swing arson and is in the plane of the sNving aim. Àe À

   3. A deployment system according to claim I or 2, wherein the second joint is an anged to perforce sliding movcT1leTlt relative to the swing aria in the direction ofthe first transla.io!1al À A degree offreedom to move the moveable wing surface relative to the main Wil1g. Àe À À

   À JO 4 A deployment system according to any one of the preceding claims, wherein the second joint is arranged such that the second translational degree of freedom is in a directio that is substantially parallel to the longitudinal axis of the moveable wing surface A deployment system according to claim 4, wherein the second joint is arranged to perform free sliding movement in the direction of the second translational degree of freedom that allows, iT1 use, lost notion between the movable wing surface and the main wing.

   6 A deployTlleTlt system according to any one of the preceding claims wherein the second joint is arranged such that the first rotational degree of fi-eedom is about an axis that is substantially perpendicular to the longitudinal axis oi the SNVil1g aT1n and is iT1 the plane ofthe swing allll.

   7. A dcp]oyment system according to any one of the preceding claims wheiein the second joint is arranged such that the second r otational degree of freedom is about an axis that is substantially parallel to the longitudinal axis of the movcable wing surface.

   S. A deployment system according to any one of the preceding claims wherein the first s joint is arranged such that the first rotational degree of freedom is about an axis in a direction substantia]]y perpendicular to the longitudinal axis of the swing am and is in the plane of the swing awl, and the second rotational degree of freedom is about an axis substantially parci]]e] to the longitudinal axis of the moveable wing surface.

   9. A deployment system according to any one of the preceding claims, ';, hcrein the 0 second joint is a sliding spherical joint.

   10. A deployment system according to any one of the preceding claims, including a second swing arm assembly pivotably connected to the main wing and a connector mec]lanisin for connecting the movable wing surface to the swing any, the connector mechanism including e a first joint having at least first and second rotational teepees of freedom and at least a first translational degree of freedom and a second joint having at least first and second rotational degrees of fi-eedom and at least first and second translational degrees of fi-eed'm. :e

   I] . A deployment system according to claim 10, wherein the first joint is arranged such À. that the first translational degree of freedom is in a direction that is substantially parallel to the longitudinal axis of the moveable wing surface.

   12. A deployment system according to claim 10 or] I, wherein the first joint is arranged to perform flee sliding movement in the direction ofthe first translation] degree of freedom that allows, in use, lost motion between the movable wing surface and the main wing section.

   13. A deployment system according to any one of the pi-eceding claims, wherein the 2s moveab]e wing surface and the main wing are an-anged such that a part of the moveable wing surface remains substantially in contact with a part of the main \N'i.lg section W]len the moveable wing surface is positioned behveen a fuller retracted position and a patial]y deployed position and a slot is created between the main wing and the moveable wing surface -] 7 when the moveable ending surface is positioned between the partially deployed position and a fully deployed position.

   ] 4. A deployment system according to claim 13, wherein the moveable wing surface, any assemblies and the main wing section are arranged such that the size and shape of'the slot is s controlled.

   15. A deployment system according to any one of the preceding claims, including a plurality of moveable ovine surfaces distributed along the main wing section, wherein each nlOVable wing section is connected to a plurality of swing any assemh]ies and the drive means includes a mechanism linking at least one swing am assembly associated with each moveable lo wing surface such that in use' the drive means deploys the moveable wing 4ur4,i.ces substantial!>, simultaneously.

   16. An aircraft including a dcploymeilt system according to any one of claims to any one ,. of the preceding claims. e...

   17. A deployment system substantially as described herein witl1 reference to arid as 0.. À

   s illustrated by the accompanying drawings. À: À À À À À À. À À À À.