Abstract:
A slat support and deployment apparatus comprising a master slat support and deployment assembly and a slave slat support and deployment assembly is disclosed. The master and the slave slat support and deployment assembly each include an arm having a free end attachable to the same slat at spaced locations along its length for deployment and retraction of said slat in a direction generally parallel to a wing in response to simultaneous movement of said arms. The master and the slave slat support assemblies each include a coupling for attaching said free end of each arm to a slat and the coupling that couples the free end of the arm of each slat support and deployment assembly to a slat is configured to allow movement of that slat relative to said free end of said arm of each slat support and deployment assembly during deployment and retraction of said slat.

Description:
[0001]    The present invention relates to a slat support and deployment coupling for coupling a slat support and deployment assembly to a slat on the leading edge of an aircraft wing. 
       BACKGROUND 
       [0002]    Aircraft need to produce varying levels of lift for take-off, landing and cruise. A combination of wing leading and trailing edge devices are used to control the wing coefficient of lift. The leading edge device is known as a slat. On larger aircraft there may be several slats spaced along the wing edge. During normal flight the slats are retracted against the leading edge of the wing. However, during take-off and landing they are deployed forwardly of the wing so as to vary the airflow across and under the wing surfaces. The slats usually follow an arcuate or curved path between their stowed and deployed positions. By varying the extent to which the slat is deployed along said path, the lift provided by the wing can be controlled. 
         [0003]    An assembly is required to support and guide movement of a slat between stowed and deployed positions. 
         [0004]    A slat support and deployment assembly has already been described in the Applicant&#39;s own earlier application No. EP2433863, the entire content of which is incorporated herein by reference. 
         [0005]    The aforementioned application refers to a support assembly for deployment and retraction of an aero surface from an aircraft that includes a guide track, a primary support arm having one end coupled to a carriage mounted on the track such that the primary support arm is rotatable relative to the carriage about multiple axes, and a control arm having one end coupled to the primary support arm and a second end pivotably attachable to a fixed support forming part of the structure of the aircraft. The assembly is configured such that, when the carriage is driven along the guide track, the control arm causes the primary support arm to pivot about said multiple axes to deploy and/or retract an aero surface pivotally attached to an opposite end of the primary support member along an arcuate path. 
         [0006]    A more detailed description of the structure and function of the slat deployment assembly will now be described with reference to  FIGS. 1 and 2 , which have been taken from our earlier application identified above. 
         [0007]    Referring primarily to  FIG. 1 , the assembly  1  comprises a carriage  2  having a body  3  mounted on an elongate track  4 . The track  4  is rigidly attached to the wing structure of an aircraft so that it remains stationary relative to a rib  5  forming part of the wing structure. The track  4  has a flange  6  that may be placed against part of the wing structure. Holes (not shown) may extend through the flange  6  to allow bolts or other conventional fasteners to be inserted therethrough to facilitate attachment of the track  4  to the wing structure. The track  4  also has a carriage mounting portion  7  attached to the flange  6  via a thinner, necked region  8 . 
         [0008]    A rotatable threaded drive shaft  9  extends along the track  4  within a recess  10  in the track  4  and threadingly engages within a drive coupling portion  11  of the carriage  2  that extends into the recess  10  such that, when the threaded shaft  9  rotates, in response to rotation of a drive motor (not shown) drivingly coupled to the shaft  9 , the carriage  3  slides along the elongate track  4 , its direction depending on the direction of rotation of the shaft  9 . 
         [0009]    The carriage  3  is supported on the track  4  by a pair of upper and lower bearings (not shown) each inserted into a recess in the carriage  3 . 
         [0010]    The carriage  3  has spaced parallel wall portions  12  extending from the body  3  between which is mounted an axle  13  having a generally square-shaped cross-section. The axle  13  is mounted to the carriage  3  for rotation about its longitudinal axis ‘H’ relative to the carriage  3 . 
         [0011]    A primary support arm  14  has a pair of upper and a pair of lower arm portions or legs  14   a ,  14   b . Each of the upper arm portions  14   a  and each of the lower arm portions  14   b  extend from a cylindrical mounting boss  15   a ,  15   b  located at one end of the upper and lower arm portions  14   a ,  14   b . The axle  13  locates in the space between these mounting bosses  15   a ,  15   b  at the end of each arm portion  14   a ,  14   b  and the primary support arm  14  is coupled to the axle  13  by a pin (not shown) that extends through the axle  13  and a hole  16  in each mounting boss  15   a ,  15   b , thereby pivotally connecting the primary support arm  14  to the axle  13  for rotation about an axis ‘I’, which is at 90 degrees to axis ‘H’. The pivotal connection of the axle  13  to the carriage  3  for rotation about axis ‘H’ and the pivotal connection of the primary support arm  14  to the axle  13  for rotation about axis ‘I’ together form a universal joint to enable free movement of the primary support arm  14  relative to the carriage  3  as the carriage  3  slides along the guide track  4 . 
         [0012]    The primary support arm  14  has a cylindrical boss  17  with an aperture  18  at its opposite end to receive a pin (not shown) so as to pivotally couple the primary support arm  14  to a slat about axis J-J, as will become apparent from a description of the preferred embodiments of the present invention. 
         [0013]    A secondary support or control arm  18  is coupled to the primary support arm  14  between opposite ends of the primary support arm  14  via a cylindrical barrel rotating in an annulus with a slot with the arm pivoting about the pin to form a universal joint assembly  19 . The primary support arm portions  14   a ,  14   b  each have an intermediate mounting boss  20   a ,  20   b  positioned between each of the upper arm portions  14   a  and each of the lower arm portions  14   b  midway along the length of the primary support arm  14 . Each of the mounting bosses  14   a ,  14   b  are parallel to and spaced from each other. A shaft  21  is connected to and extends between the intermediate mounting bosses  20   a ,  20   b  and has a central part-spherical region that forms a male bearing seat or surface. One end of the secondary control arm  18  that connects to the primary support arm  14  has a collar  22  that defines an inner or female part spherical bearing surface that locates around, and mates with, the part spherical bearing surface formed on the shaft  21 , so that the control arm  18  can rotate relative to the primary support arm  14  in all directions. 
         [0014]    The control arm  18  of the invention comprises support arm portions  23  which diverge at an angle away from the collar  22  and, from each other. Each support arm portion  23  terminates in an annular member  24  that is received within an opening  25  in the rib  5 . A pin (not shown) is associated with each annular member  24  and locates in the rib  5  so that it passes through each annular member  24  to facilitate pivotal connection of each annular member  24  to the rib  5  for rotation of the secondary control member  18  about an axis K. 
         [0015]    Axes I and J at opposite ends of the primary support member  14  are parallel to each other and remain so during deployment and retraction of the slat. However, it will be noted that axis K extending through the annular members  24  is at an angle relative to axes I and J i.e. it is displaced through a compound angle in both directions so that it is rotated about the longitudinal axis H of the axle  13  as well as being displaced through an angle such that it not perpendicular to the longitudinal axis H. This arrangement produces an arcuate path to the free end of the primary support arm  14  when the carriage  3  slides laterally along the track  4  and the primary support arm  14  rotates about axes H and I. 
         [0016]    To deploy a slat coupled to the primary support arm  14 , the motor is driven to rotate the threaded shaft  9  so that the carriage  3  moves in a first direction S along the track  4 . As the carriage  3  moves, the primary support arm  14  rotates relative to the carriage  3  about the axis I, and also relative to the control arm  18  about the spherical joint  19 . At the same time, the axle  13  rotates about its axis H such that the primary support member  14  also moves downwardly, the spherical ball joint  19  between the primary and secondary support members  14 ,  18  allowing this movement. As a result, the free end of the primary support arm  14  follows an arcuate path in an outward direction away from the track  4 , i.e. in the direction of arrow ‘T’ in  FIG. 1 . 
         [0017]    To retract the slat, the direction of rotation of the threaded shaft  9  is reversed so that the carriage  3  moves along the track  4  in the opposite direction thereby causing the primary support member  14  to follow a return arcuate path back towards the track  4 . 
         [0018]    It will be appreciated that at least two slat deployment assemblies are required to effectively support and control the deployment of each slat. The slat support assemblies are spaced from each other in a direction along the length of the wing in order to provide adequate support for, and controlled deployment of, the slat along its entire length.  FIG. 2  shows such an arrangement, with a slightly modified slat and carriage assembly, each of which are attached to a slat  26 . Despite this modification, the principle and operation described with reference to  FIG. 1  remains the same. 
         [0019]    During assembly, it is important to ensure that when a slat is coupled to the slat support assemblies, the slat is properly aligned with the wing and, in particular, that the upper trailing edge of the slat sits flush with, and against, the leading edge of the wing when the slat is in a closed or withdrawn position, such as during level flight. 
         [0020]    It is also apparent that there may be slight differences in the deployment path followed by each slat support assembly during deployment, caused by build tolerances, misalignment or uneven wear between slat support assemblies. This can result in undue stress being placed on the slat if one or more of the slat support assemblies coupled to the same slat is effectively attempting to drive the slat in a slightly different direction or into a different position between its stowed and deployed positions. 
         [0021]    The effects of wing bending must also be considered so that no undue stress is placed on the slat during deployment or retraction. 
         [0022]    In one embodiment of the present invention, it has been assumed that the slat itself is sufficiently flexible to absorb any misalignments caused by build tolerances or uneven support assembly deployment, as well as withstand any deflection caused by wing bending. This embodiment therefore only provides a slat support assembly coupling that is provided with means to enable fine-adjustment of the position of the slat relative to the slat support assembly and so relative to the wing to which the slat support assembly is mounted, so that the shut-line between the trailing edge of the slat and the leading edge of the wing to which the slat is mounted can be precisely adjusted during assembly to ensure that the upper surface of the slat and the upper surface of the wing lie flush with each other when the slat is in its stowed position. 
         [0023]    In another, preferred embodiment of the invention, there is provided a slat support coupling that has a construction that accommodates and adjusts for any misalignments and wing bending deflections, so that the slat itself experiences only minimal stress. 
         [0024]    From the foregoing, it will be appreciated that the present invention seeks to overcome or alleviate one or more of the problems referred to above. 
       SUMMARY OF THE INVENTION 
       [0025]    According to an aspect of the present invention, there is provided a slat support and deployment apparatus comprising a master slat support and deployment assembly and a slave slat support and deployment assembly, the master and the slave slat support and deployment assembly each including an arm having a free end attachable to the same slat at spaced locations along its length for deployment and retraction of said slat in a direction generally parallel to a wing in response to simultaneous movement of said arms, the master and the slave slat support assembly each including a coupling for attaching said free end of each arm to a slat, wherein the coupling that couples the free end of the arm of each slat support and deployment assembly to a slat is configured to allow movement of that slat relative to said free end of said arm of each slat support and deployment assembly during deployment and retraction of said slat. 
         [0026]    The coupling that couples the free end of the arm of each slat support and deployment assembly to a slat may be configured to allow movement of that slat relative to said free end of said arm of each slat support and deployment assembly in multiple directions. 
         [0027]    Said movement in multiple directions may comprise rotation about a first, second and third axes, the first, second and third axes being at right-angles to each other. 
         [0028]    The coupling that couples the free end of the arm of the slave slat support and deployment assembly to a slat may also allow rotation of the slat about a fourth axis, relative to the slave slat support and deployment assembly, said fourth axis being parallel to the second axis. 
         [0029]    The coupling that couples the free end of the arm of the slave slat support and deployment assembly to a slat may also allow axial movement of the slat relative to the slave slat support and deployment assembly, in a direction along the fourth axis. 
         [0030]    The coupling that couples the free end of the arm of the master slat support and deployment assembly to a slat may be configured such that movement of a slat relative to the free end of the master slat support assembly during deployment and retraction of a slat is limited to rotation about a single axis. 
         [0031]    A slat attached to the master and slave slat support and deployment assemblies may follow a path that is substantially defined by the path of the free end of the arm of the master slat support and deployment assembly during deployment and retraction of a slat, wherein the coupling that couples the slave slat support assembly to the slat may be configured to allow relative movement between the slat and the free end of the arm of the slave slat support assembly when the path defined by the free end of the arm of the master slat support and deployment assembly differs from a path defined by the free end of the arm of the slave slat support and deployment assembly during deployment and retraction of a slat. 
         [0032]    The coupling member that couples the slave slat support assembly to a slat may comprise a first cooperating element pivotally mounted to said free end of the arm of the slave slat support and deployment assembly for rotation of said first cooperating element relative to said free end of the arm about the first axis. 
         [0033]    The coupling member that couples the slave slat support assembly to a slat may comprise a second cooperating element having a body, one end of said body being pivotally mountable to a slat for rotation relative thereto about the second axis at right angles to the first axis and in a direction that extends along the length of a slat. 
         [0034]    An intermediate element may extend between and couple the first and second cooperating elements together such that the second cooperating element is rotatable relative to the first cooperating element about the third axis and the fourth axis. 
         [0035]    The first cooperating element may include a cylindrical mounting hub and the intermediate element may be mounted on said hub for rotation of said intermediate element relative to the first cooperating element about the third axis which is defined by the longitudinal axis of said hub. 
         [0036]    The second cooperating element may comprise a yoke formed from two parallel spaced walls extending from an opposite end of the body, the intermediate element being received in said yoke between said walls, said intermediate element being pivotally mounted to said second cooperating element for rotation of the second cooperating element relative to the first cooperating element about said fourth axis. 
         [0037]    Said parallel walls may be spaced from each other by a distance which exceeds the width of the intermediate element received between them. 
         [0038]    The intermediate element may be mounted to said second cooperating element between said parallel walls such that said first and second cooperating elements are slideable relative to each other in a direction along the fourth axis. 
         [0039]    A boss may protrude from each of said parallel walls and the intermediate element may comprise an opening in each surface facing the side walls, a boss being received in each opening to mount the intermediate element to the second cooperating element for rotation about the fourth axis and such that it can slide in a direction along said fourth axis. 
         [0040]    The slat support and deployment apparatus may comprise a slave connecting link configured to extend between a slat and the first cooperating element of the coupling of the slave slat support assembly. 
         [0041]    The slave connecting link may be configured so that it attaches to a slat and to the first cooperating element via bearing elements such that the slave connecting link and slat are pivotable relative to each other in any direction about one bearing element and, the slave connecting link and the first cooperating element may be pivotable relative to each other in any direction about the other bearing element. 
         [0042]    The slave connecting link may comprise a pair of spaced parallel plates having a mounting pin extending therebetween having an axis, said pin including a slat mounting bearing, said bearing having an axis parallel to but offset from the pin mounting axis. 
         [0043]    Said bearing may be a spherical bearing. 
         [0044]    The bearing element may be rotatable about its mounting axis during assembly so that a slat mounted to said mounting bearing rotates about the second axis to finely adjust the position of a slat during assembly. 
         [0045]    The coupling member that couples the free end of the arm of the master slat support assembly to a slat may comprise a first cooperating element pivotally mounted to said free end of said arm for rotation of said first cooperating element relative to said arm about a first axis. 
         [0046]    The coupling member that couples the arm of the master slat support assembly to a slat may comprise a second cooperating element pivotally mountable to a slat for rotation relative thereto about a second axis at right angles to the first axis. 
         [0047]    The second cooperating element may be mounted to the first cooperating element for rotation about a third axis at right angles to the first axis and the second axis. 
         [0048]    The slat support and deployment apparatus may comprise a master connecting link configured to extend between a slat and the second cooperating element. 
         [0049]    The master connecting link may comprise a bearing to mount a slat to said master connecting link. 
         [0050]    The bearing to which the slat is mountable may have a mounting pin having an axis, said pin including a slat mounting bearing, said bearing having an axis parallel to but offset from the pin mounting axis. 
         [0051]    The mounting pin may be rotatable about its axis during assembly so that a slat mounted thereto rotates about its second axis to finely adjust the position of a slat during assembly. 
         [0052]    The slat support and deployment apparatus may include a slat coupled to the free end of an arm of a master slat support and deployment assembly and to the free end of an arm of a slave slat support and deployment assembly, said arms of said master and slave slat support and deployment assemblies being movable simultaneously for deployment and retraction of said slat attached thereto. 
         [0053]    According to another aspect of the present invention, there is provided an aircraft wing having a rib structure and comprising a slat support and deployment apparatus as described above, said master and slave slat support and deployment assemblies being mounted to said rib structure. 
         [0054]    According to another aspect of the present invention, there is provided a slat support and deployment apparatus comprising at least two slat support and deployment assemblies, each slat support and deployment assembly including an arm having a free end attachable to the same slat at spaced locations along its length for deployment and retraction of said slat in a direction generally parallel to a wing in response to simultaneous movement of said arms, each slat support assembly including a coupling for attaching said free end of each arm to a slat, wherein each coupling includes an adjuster to enable fine adjustment of the position of a slat relative to said free ends of each of said arms during assembly. 
         [0055]    Each coupling may comprise a first cooperating element pivotally mounted to the free end of each arm for rotation about a first axis and a second cooperating element pivotally mountable to a slat and rotatable about a second axis, the first cooperating element being pivotally mounted to the second cooperating element for rotation about a third axis at right angles to the first and second axes. 
         [0056]    The slat support and deployment assembly may comprise a connecting link that extends from the second cooperating element at a location between the point at which the second cooperating element is pivotally mountable to a slat and the point at which the first cooperating element is mounted to the second cooperating element, said connecting link being pivotally attachable to the slat at a location spaced from the pivotal mounting of the second cooperating element to the slat for rotation relative to the slat about a fourth axis parallel to the second axis. 
         [0057]    The slat may be coupled to the connecting link via an eccentrically mounted bearing such that, when the bearing is rotated during assembly the slat rotated about the second axis to finely adjust the position of the slat relative to the free end of the slat support and deployment assembly. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0058]    Embodiments of the invention will now be described, by way of example only, with reference to  FIGS. 3 to 8  of the accompanying drawings, in which: 
           [0059]      FIG. 1  is a perspective view of a slat support assembly as disclosed in the Applicant&#39;s own earlier application referred to above; 
           [0060]      FIG. 2  is a front perspective view of a pair of assemblies attached to a slat that depends from the leading edge of an aircraft wing, as disclosed in the Applicant&#39;s own earlier application referred to above; 
           [0061]      FIG. 3  is a rear perspective view of a pair of assemblies attached to a slat according to the present invention and showing a coupling at the free end of the arm of each slat support and deployment assembly to couple said arms to a slat, one of said slat support assemblies being a master slat support and deployment assembly and the other of said slat support and deployment assemblies being a slave slat support and deployment assembly; 
           [0062]      FIG. 4A  is a front perspective view of the master slat support and deployment assembly shown in  FIG. 3 ; 
           [0063]      FIG. 4B  is an enlarged view of the coupling attached to the free end of the arm of the master slat support and deployment assembly shown in  FIG. 4A ; 
           [0064]      FIG. 5A  is a front perspective view of the slave slat support and deployment assembly shown in  FIG. 3 ; 
           [0065]      FIG. 5B  is an enlarged view of the coupling attached to the free end of the arm of the slave slat support and deployment assembly shown in  FIG. 5A ; 
           [0066]      FIG. 6  is a rear perspective view of the master slat support and deployment assembly shown in  FIG. 4A ; 
           [0067]      FIG. 7  is a rear perspective view of the slave slat support and deployment assembly shown in  FIG. 5A ; 
           [0068]      FIG. 8  is an enlarged perspective view of the coupling attached to the free end of the arm of the slave slat support assembly, showing some hidden detail aspects in dashed lines; 
           [0069]      FIG. 9  is a side sectional elevation through the coupling attached to the free end of the arm of the slave slat support assembly, with a slat mounted thereto; 
           [0070]      FIG. 10  is a cross-sectional view taken along the line B-B in  FIG. 9 ; 
           [0071]      FIG. 11  is A rear perspective view of a pair of assemblies attached to a slat according to an alternative embodiment of the present invention and showing a coupling at the free end of the arm of each slat support and deployment assembly to couple said arms to a slat, each of said couplings allowing fine adjustment of the position of the slat during assembly; 
           [0072]      FIG. 12A  is a rear perspective view of a pair of assemblies attached to a slat that depends from the leading edge of an aircraft wing, according to another embodiment of the invention; 
           [0073]      FIG. 12B  is a perspective view of one of the couplings shown in  FIG. 12A ; 
           [0074]      FIG. 13  is a side view of another alternative embodiment of a coupling that is suitable for use as the master coupling of the first embodiment (described with reference to  FIGS. 3 ,  4 A,  4 B and  6 ) or as the coupling used in the second embodiment (described with reference to  FIG. 12 ); 
           [0075]      FIG. 14  is a first perspective view of the coupling shown in  FIG. 13 ; and 
           [0076]      FIG. 15  is a second perspective view of the coupling shown in  FIG. 14 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0077]    With reference to  FIG. 3 , there is shown a pair of slat support and deployment assemblies  30 ,  31  attached to a single slat  32 . One of the assemblies  30  forms a ‘master’ slat support and deployment assembly and the other forms a ‘slave’ slat support and deployment assembly, for reasons that will become apparent. Each assembly is identical or similar to those described with reference to  FIGS. 1 and 2  referred to above. However, the free end of the primary support arm  33 ,  34  of each slat support assembly is provided with a coupling  35 , 36  to attach a respective slat support assembly  30 , 31  to the slat  32 . Embodiments of these couplings  35 ,  36 , will now be described in detail. 
         [0078]    A first embodiment of the coupling  35  that is used to couple the master slat support and deployment assembly  30  to the slat  32  is most clearly shown in  FIGS. 4A ,  4 B and  6 . The coupling  35  is also shown coupled to a slat  32  in  FIG. 3  (the slat support and deployment assembly  30  shown on the right-hand side of the drawing). 
         [0079]    A pin  36  pivotally mounts a primary cooperating member or bracket  38  to a cylindrical hub  39  at the free end of the primary control arm  33  for rotation about a first axis A-A. The hub  39  is received between a pair of parallel spaced flanges  40  extending from a central body portion  41  of the primary cooperating member  38 . 
         [0080]    A cylindrical boss (not shown) extends from the central body portion  41  of the primary cooperating member  38  and is received within a secondary cooperating member or knuckle body  42  so that a secondary cooperating member  42  is rotatable relative to the primary cooperating member  38  about a longitudinal axis B-B (as shown in  FIGS. 4B and 6 ) extending through the cylindrical boss. The cylindrical boss is retained within the secondary cooperating member  42  by an end cap (not shown). The axis B-B is at right angles to the axis A-A. 
         [0081]    The secondary cooperating member  42  is received in and pivotally attached to a mount  43  (see  FIG. 3 ) that is formed on and is integral with the underside of the slat  32 . In this embodiment, the mount  43  comprises a pair of parallel walls  44  which are spaced by a distance at least slightly greater than the width of the secondary cooperating member  42 . The secondary cooperating member  42  is received between the parallel walls  44  and is pivotally attached to the slat  32  by a main slat attachment pin  45  (see  FIG. 3 ) that extends through aligned holes in each wall  44  and through a hole  46  (see  FIGS. 4A ,  4 B and  6 ) extending through the secondary cooperating member  42 . The secondary cooperating member  42  is rotatable relative to the slat  32  about an axis C-C (see  FIGS. 4B and 6 ) coaxial with the longitudinal axis of the pin  45 . The axis C-C extends at right angles to axis A-A and B-B. 
         [0082]    A master connecting link  47  is coupled to and extends between the secondary cooperating member  42  and a flange  48  extending from the mount  43  spaced from the axis C-C. The master connecting link  47  comprises two integral U-shaped bracket portions extending in opposite directions. The secondary cooperating member  42  is received within the ‘mouth’ of one ‘U’ and a pin  49  extends between the arms  50  of the U-shaped bracket and through the secondary cooperating member  42  placed between them to pivotally attach the connecting link  47  to the secondary cooperating member  42 . 
         [0083]    Likewise, the flange  48  extending from the mount  43  is received within the ‘mouth’ of the other ‘U’ of the connecting link  47  and a pin  51  extends between the arms  52  of that U-shaped bracket and through the flange  48  positioned between them, to pivotally connect the connecting link  47  to the flange  48 . 
         [0084]    The pin  51  that extends through the flange  48  has a mounting axis about which it is rotatable relative to the connecting link  47 . However, a portion  51   a  of the pin  51  that extends between the arms  50  is eccentrically shaped and has an axis, which is parallel to but offset from the mounting axis. 
         [0085]    When the pin  51  is positioned so that it extends between the arms  50  and through a flange  48 , the pin  51  can be rotated about its mounting axis during assembly so as to precisely control or adjust the position of the slat  32  against the leading edge of an aircraft wing. When the pin  51  is rotated, the eccentric portion  51   a  pivots about its axis offset from the mounting axis, thereby causing the slat  32  to pivot about axis C-C relative to the secondary cooperating element  42 , as the eccentric portion cooperates with the flange  48 . Once the desired position of the slat  32  has been achieved, the pin  51  can be tightened so that no further rotation of the pin  51  can take place until further adjustment is necessary. 
         [0086]    It will be appreciated that the master coupling is essentially fixed once the slat position adjustment has been carried out so that the slat  32  will follow a path that is directly linked to the path followed by the end of the master slat support and deployment assembly  30 . 
         [0087]    A first embodiment of the coupling  36  of the slave slat support and deployment assembly  31  will now be described in more detail with reference to  FIGS. 3 ,  5 A,  5 B,  7 ,  8 ,  9 ,  10  and  11 . 
         [0088]    As with the master slave slat support and deployment assembly  30 , a pin  60  pivotally mounts a primary cooperating member or bracket  61  to a cylindrical hub  39  at the free end of the primary control arm  33  for rotation about a first axis A-A. The hub  39  is received between a pair of parallel spaced flanges  62  extending from a central body portion  63  of the primary cooperating member  61 . 
         [0089]    A cylindrical boss  64  (see  FIGS. 8 ,  9 ,  10  and  11 ) extends from the central body portion  63  of the primary cooperating member  61  and is rotatably mounted within an intermediate cooperating member  65  so that the primary cooperating member  61  and intermediate cooperating member  65  are rotatable relative to each other about a second axis B-B extending through the longitudinal axis of said cylindrical boss  64 . The cylindrical boss  64  can be retained within the intermediate cooperating member  65  by end cap (not shown) that is fastened to the end of the boss  64 . The second axis B-B is at right angles to the first axis A-A. 
         [0090]    A secondary cooperating member  66  is pivotally mounted to a mount  67  extending from and integral with the underside of the slat  32  in the same way as described with reference to the master slat support and deployment assembly. In this embodiment, the secondary cooperating member  66  has a hole  68  that is aligned with a hole  69  in spaced parallel walls  70  of the mount  67  and a slat mounting pin  71  (see  FIG. 8 ) extends through said holes  68 ,  69  to couple the slat  32  to one end of the secondary cooperating member  66  for rotation about a third axis C-C, at right angles to the first and second axes, A-A and B-B, respectively. 
         [0091]    The opposite end of the secondary cooperating member  66  has two spaced parallel wall portions  72  to define a space or yoke  73  (see  FIG. 10 ) therebetween, and the intermediate cooperating member  65  is received within said yoke  73 . The width of the intermediate cooperating member  65  is less than the width of the space between said parallel wall portions  72  so that the intermediate cooperating member  65  is spaced from the each of the wall portions  72  within the yoke  73 , for reasons that will become apparent. 
         [0092]    Opposite surfaces of the intermediate cooperating member  65  facing the parallel wall portions  72  have holes (not shown) and a boss  87  extends from each parallel wall portion  72  in a direction towards the other parallel wall portion  72  which are rotatably received within a corresponding hole  86  in opposing surfaces of the intermediate cooperating member  65 , so as to rotatably couple the secondary cooperating member  66  to the intermediate cooperating member  65  for relative rotation about an axis D-D (see  FIGS. 5B and 8 ). Axis D-D is parallel to axis C-C, but at right angles to axes A-A and B-B. 
         [0093]    As there is a space between the intermediate cooperating member  65  and the parallel wall portions  72 , the secondary cooperating member  66  and the intermediate member  65  can slide relative to each other in a direction along the axis D-D. The cooperating holes  86  and bosses  87  that couple the secondary cooperating member  66  to the intermediate cooperating member  65  are sized so that the intermediate cooperating member  65  and the secondary cooperating member will remain coupled together throughout the entire range of sliding movement relative to each other. 
         [0094]    A slave connecting link  75  is coupled to and extends between the primary cooperating member  61  and a flange  79  (see  FIG. 9 ) on the slat  32  that is spaced from axis C-C. The primary cooperating member  61  has a web  76  (see  FIGS. 9 and 10 ) protruding upwardly from its body portion  63  in which an aperture  77  is formed. The connecting link  75  comprises a pair of spaced parallel plates  78  and a spherical bearing  85  is mounted to and extends between each of the plates  78  at one end and locates in the aperture  77  in the web  76  so as to mount the connecting link  75  to the primary cooperating member  61  for rotation of the connecting link  75  relative to the primary cooperating member  61  in any direction. 
         [0095]    The opposite end of the connecting link  75  is mounted to the flange  79 , which is received between each of the plates  78 . A mounting pin  80  is received in and extends between each plate  78  for rotation about a mounting axis during assembly. The mounting pin  80  has an eccentric portion extending between each plate  78  so that, when the mounting pin  80  is rotated about its mounting axis, the eccentric portion rotates about its axis, offset from the mounting axis. As a result of cooperation of the eccentric portion with the flange  79 , the slat  32  is caused to pivot about axis C-C when the pin  80  is rotated, to enable fine adjustment of the position of the slat  32  relative to the leading edge of the aircraft wing during assembly or servicing. 
         [0096]    During deployment of a slat  32 , the master and slave slat support assemblies  30 , 31  are both driven simultaneously and the slat  32  follows the path defined by the master slat support and deployment assembly  30 . 
         [0097]    The slave slat support and deployment assembly  31  is provided with a coupling  36 , as described above, which accommodates any wing bending, misalignments and any differences in the deployment path followed by the slave slat support assembly  31  relative to the primary slat support assembly  30 . In particular, the slat  32  can move, together with the secondary cooperating element  66 , laterally along the fourth axis D-D, due to the spacing and coupling between the secondary cooperating element  66  and the intermediate cooperating element  65 . This lateral movement is also permitted by the spherical bearings that couple the connecting link  75  to the primary cooperating element  61  and to the flange  79  on the slat  32 . 
         [0098]    It will also be appreciated that the coupling  36  that couples the slat  32  to the slave slat support and deployment assembly  31  also allows pivotal movement of the secondary cooperating element  66  relative to the intermediate cooperating element  65  about axis D-D. Furthermore, the intermediate cooperating element  65  is also rotatable relative to the primary cooperating element  61  about the second axis B-B. The spherical bearings coupling the connecting link  75  to each of the primary cooperating element  61  and the flange  79  on the slat  32  also permitting pivotal movement of the secondary cooperating element  66  relative to the primary cooperating element  61  so that any misalignment between the master and slave slat support assemblies  30 ,  31  can be absorbed as a result of this movement and no undue stress is placed on the slat  32 . 
         [0099]    It will be appreciated that the relative rotation or movement between components described above may be limited. However, it will be noted that wing bending, misalignment and irregular deployment of the slat support and deployment assemblies will only cause very small differences that can easily be accommodated by the coupling  36  of the slave slat support assembly  31 , which effectively acts as a type of universal joint between the slat and the slave slat support and deployment assembly that takes up any small misalignments. 
         [0100]    A second embodiment of the invention will now be described with reference to  FIGS. 12A and 12B . In this embodiment, the slave coupling allows the same movement as the master coupling; rotation about the three axes A-A, B-B and C-C. However, this embodiment of the coupling differs from the previous embodiment because it does not facilitate the fourth axis D-D. Using the same coupling for both the master and the slave assemblies requires fewer unique components, reducing costs and simplifying maintenance. 
         [0101]    The slave coupling of this embodiment does not allow the sideways sliding movement that was described in the first embodiment. Therefore, the slat will deform during deployment and retraction because of assembly misalignments or imperfect synchronisation between the master and slave slat support and deployment assemblies and actuators. However, the coupling does allow for adjustments of the slat position relative to the slat actuators at both the master and slave couplings so the amount of deformation in the slat will be small and the stresses induced in the slat should be negligible. 
         [0102]      FIG. 12A  shows two couplings  88  connecting the slat  32  with the primary support arms  33  of the master and slave slat support and deployment assemblies. Similar to the master coupling  35  previously described before, the couplings  88  comprise a primary cooperating member  89  that pivotally attaches to the cylindrical hub  39  of the primary support arm  33  about axis A-A. The couplings  88  also comprise a secondary cooperating member  90  that pivotally attaches to the slat  32 , via a mount  91 , about axis C-C. 
         [0103]      FIG. 12B  shows an enlarged view of the coupling  88  of  FIG. 12A . In this embodiment, the primary cooperating member  89  comprises a ‘U’ shaped bracket with a main body portion  110  and two spaced parallel flanges  111 . The secondary cooperating member  90  also comprises a ‘U’ shaped bracket with a main body portion  112  and two spaced parallel flanges  113 . 
         [0104]    As before, the main body portion  112  of the secondary cooperating member  90  comprises a hole (not shown) for receiving a cylindrical boss (not shown) extending from the main body  110  of the primary cooperating member  89 , pivotally connecting the primary and secondary cooperating members  89 ,  90  about axis B-B. A mount  91  is attached to, or integrally formed with, the slat  32  and comprises a block with a hole extending through it defining axis C-C. The two spaced parallel flanges  113  of the secondary cooperating member  90  are spaced slightly further apart than the width of the mount  91  and each flange  113  comprises a hole so that the mount can be received between the spaced parallel flanges  113  and a slat mounting pin  114  positioned through the aligned holes to pivotally connect the secondary cooperating member  90  to the slat  32  about axis C-C, which is perpendicular to axes A-A and B-B. 
         [0105]    Similar to the connecting link previously described for the master coupling  35  of the first embodiment, a connecting link  92  joins the secondary cooperating member  90  to a second portion of the mount  115 . The connecting link  92  is coupled to and extends between the secondary cooperating member  91  and the mount  115 , spaced from the axis C-C. The connecting link  92  comprises two spaced parallel plates  116 . Each plate has a first end that is pivotally connected to the secondary cooperating member  90  via a pin  93  along an axis that is parallel to and spaced from C-C. Each plate also comprises a second end that is pivotally attached to the mount  115  via a pin  94  along a mounting axis that is parallel to and spaced from C-C. 
         [0106]    As with the connecting link  92  of the couplings previously described, the pin  94  that extends through the connecting link  92  and the mount  91  has a mounting axis about which it is rotatable relative to the mount  91 . A portion of the pin  94  located between the spaced parallel plates  116  is eccentrically shaped, with an axis that is parallel to and spaced from the mounting axis of the pin  94 . Therefore, the pin  94  rotates relative to the connecting link  92  about an axis that is spaced from and parallel to the mounting axis. 
         [0107]    The pin  94  can be rotated about its mounting axis during assembly so as to precisely control or adjust the position of the slat  32  against the leading edge of an aircraft wing. When the pin  94  is rotated, the eccentric portion pivots about its axis offset from the mounting axis, thereby causing the slat  32  to pivot about axis C-C relative to the secondary cooperating element  90 . Once the desired position of the slat  32  has been achieved, the pin  94  can be tightened so that no further rotation of the pin can take place until further adjustment is necessary. 
         [0108]      FIGS. 13 ,  14  and  15  show an alternative embodiment of a coupling  95  that is suitable for use as the master coupling of the first embodiment (described with reference to  FIGS. 3 ,  4 A,  4 B and  6 ) or as the coupling used in the second embodiment (described with reference to  FIG. 12 ). This coupling  95  allows rotation about axes A-A, B-B, and C-C as previously described, and has a connecting link for making adjustments, but does not allow the sliding relationship of the slave coupling of the first embodiment. 
         [0109]    As before, the coupling  95  shown in  FIGS. 13 ,  14  and  15  comprises a primary cooperating member  96  and a secondary cooperating member  97 . The primary cooperating member  96  comprises a main body portion  117  formed of a hollow box with one open side  98  for receiving the cylindrical hub of the primary support arm, similarly to described with previous embodiments. Two spaced parallel walls  99  of the box section  117  have aligned holes for receiving a pin  100  that passes through each hole and through the bore of the cylindrical hub of the primary support arm to pivotally mount the primary cooperating member  96  to the primary support arm about axis A-A. 
         [0110]    The primary cooperating member  96  also comprises a cylindrical boss  101  (see  FIG. 13 ) that extends from the main body portion  117  in a direction perpendicular to axis A-A and is received in a bore (not shown) in the secondary cooperating member  97 , to pivotally attach the primary and secondary cooperating members  96 ,  97  about axis B-B. 
         [0111]    The secondary cooperating member  97  also comprises a hollow box section  118  with an open face  102 —the face opposite the side with the bore for receiving the cylindrical boss  101 . As before, the secondary cooperating member  97  is pivotally attached to a mount in the slat. The mount (not shown) comprises two spaced parallel plates with aligned holes and the secondary cooperating member  97  is received between the plates and a pin  103  is positioned through both plates and through a hole in the secondary cooperating member  97  to pivotally mount the coupling  95  to the slat about axis C-C. 
         [0112]    For adjusting the position of the slat relative to the position of the slat actuator, a connecting link  104  extends between the secondary cooperating member  97  and the mount on the slat. This is necessary to be able to align the slat with the wing surface when the slat is in a retracted position and is important for limiting the effects of assembly misalignments between the master and slave slat support and deployment assemblies. 
         [0113]    In this embodiment, the connecting link  104  comprises two spaced parallel plates  105 , each comprising a first end  106  and a second end  107 , with pins  109 ,  108  extending between the plates  105  at each end  106 ,  107  respectively. The first pin  109  at the first end  106  of the connecting link  104  is pivotally attached to the secondary cooperating member  97  through a hole that extends through the secondary cooperating member  97  along an axis parallel to and spaced from axis C-C. The second pin  108  at the second end  107  of the connecting link  104  is pivotally attached to a flange with an aperture that extends from the slat mount (not shown). The second pin  108  pivots about the connecting link  104  on a mounting axis, which is parallel to and spaced from axis C-C. 
         [0114]    The second pin  108 , that pivotally attaches the connecting link  104  to the slat mount, comprises an eccentric portion  108   a  positioned in the portion of the pin  108  that is between the parallel spaced plates  105  and within the aperture of the flange. The eccentric portion  108   a  has an axis that is parallel to and spaced from the mounting axis of the pin  108 . When the pin  108  is rotated within the connecting link  104  the eccentric portion  108   a  cooperates with the aperture of the flange to rotate the slat about axis C-C. In this way, the position of the slat relative to each support and deployment assembly can be adjusted. 
         [0115]    Although the embodiments of the invention are primarily intended for use in controlling the deployment and retraction of a slat or flap from an aircraft wing, it could also be used to control any other aero surfaces including spoilers. It is also envisaged that it could be used to control, for example, the opening and closing of landing gear doors. 
         [0116]    The invention has been described with reference to two embodiments in which there is a single slave slat support and deployment assembly. However, it will be appreciated that two or more slave slat support assemblies may be used in the deployment of a single slat, together with a single master slat support and deployment assembly. 
         [0117]    It will be appreciated that the foregoing description is given by way of example only and that modifications may be made to the slat support assembly of the present invention without departing from the scope of the appended claims.