Abstract:
A primary flight control device for an aircraft, such as a flaperon attached to an aircraft wing, utilizes independent yet interactive airgap control systems designed to avoid weight penalties associated with conventionally used cam and track systems. An actuator directly controls movements of the flaperon; the flaperon motion is then used to slave separate movements of secondary flight control devices, such as a flaperon hinge panel and a cove lip door, to various positions of the flaperon for indirect control of aerodynamic air gaps during flight. The use of a bell crank for indirectly slaving the flaperon hinge panel movements to the flaperon avoids conventionally used cam and track systems. Although the cove lip door utilizes a separate linkage system, the bell crank and cove lip door linkage systems work in conjunction to assure desired aerodynamic airflows over the aircraft wing and flaperon structures.

Description:
FIELD 
     The present disclosure relates generally to aircraft flight control structures and more specifically to apparatus configured for slaving motion of a cove lip door to that of a trailing edge control device. 
     BACKGROUND 
     Various control devices are used to effectively and efficiently maneuver aircraft during various phases of flight. Some control devices are directly attached to wings of an aircraft, such as ailerons adapted for controlling “roll”, i.e. the rotational movement of an aircraft about its longitudinal axis. Spoilers may also be directly attached to aircraft wings to rapidly reduce wing lift when and as desired, particularly during various descent phases of a flight. Flaps are typically also attached directly to the wings to change their aerodynamic shapes for assuring stable flight control during slower speeds, such as during takeoff and landing phases of flight. 
       FIG. 1  is a fragmentary schematic view of a wing  10 , attached to a fuselage  12 , the wing and fuselage together depicting a portion of an aircraft  14  configured in accordance with the described related art. The wing  10  has a forward or leading edge  15  which may include deployable slats  16 , as yet another wing control device. The wing also has a trailing edge  17  that includes outboard ailerons  18  and outboard flaps  20 . The trailing edge  17  may also include inboard ailerons  22  and inboard flaps  24 . As noted earlier, the ailerons are used for roll control of the aircraft  14 , while the flaps are utilized to enhance lift control at lower speeds, e.g. for takeoffs and landings. 
     In some instances, the effective deployment of flaps may require translational movements in addition to their normal downward angular movements from stowed positions for creating spaces and/or gaps that need to be controlled for purposes of aerodynamic efficiency. Thus, arrows  26  and  28  indicate the directions, when deployed, of rearward translational movements of outboard flaps  20  and inboard flaps  24 , respectively. Typically, ailerons, including the inboard aileron  22  require no translational movement, as do the dedicated flaps  20 ,  24 . 
     The translational movement or extensions of outboard and inboard flaps  20 ,  24  of the convergent wing design of the aircraft wing  10  of  FIG. 1  would pose an issue of angular interference, if the respective flaps were immediately adjacent each other. Such interference is avoided, however, by portion of the wing  10  that includes the inboard aileron  22 , which is positioned between the flaps  20 ,  24  and involves no translational deployment. 
     In large turbofan jet aircraft, the functions of a flap and at least an inboard aileron may often be combined into a single or unitary control device called a flaperon. Since both flaps and ailerons are usually attached to the trailing edges of the aircraft wings, flaperons are also likewise attached. Thus, referring now to  FIG. 2 , the inboard aileron  22  of the aircraft  14  is shown attached to the trailing edge  32  of the wing  10 , as shown at an interface  30  of the leading edge  34  of the inboard aileron  22 . It should be noted that the inboard aileron  22  may be rotated about a hinge axis  38  into a rigid downward position  22 ″ (shown in phantom); i.e. deployed from the stowed position shown to a fixed angle along the downward arc of angle B, to function solely as a flap, even though without a gap, since at relatively slower speeds, i.e. during takeoff and landing, the outboard ailerons may be solely relied upon to effectively control roll of the aircraft  14 . 
     Since the inboard aileron  22  also function as a flap, in aviation parlance such control device is also called a “flaperon”, to the extent that it may be called upon to selectively perform both aileron or flap functions, depending on circumstances and/or phases of flight. 
     When functioning as an aileron, the so-called flaperon  22  is rotated upwardly along arc A from its stowed position as shown, up to and including a limit position  22 ′ (shown in phantom), to the extent that a functional aileron must be free to move both upwardly and downwardly. Conversely, the flaperon  22  may be rotated downwardly along arc B from its stowed position, down to and including a limit position  22 ″ (also shown in phantom). Finally, the trailing edge  32  of the wing  10  incorporates an aft-facing cove lip  36 , a volume or space in which the leading edge  34  of the flaperon may rotate in close proximity, as depicted in  FIG. 2  at the interface  30 . 
     Referring now to  FIG. 3 , the flap  24  may also be capable of acting as an aileron, and thus as a flaperon. Therefore, the flap  24  may also be variously called a flaperon  24 . However, because deployment of the flaperon  24  may involve a translational extension, the physical structure involved in its deployment must accommodate translational in addition to pivotal movement. In the related art structure shown, a hinge panel  40 , configured for management of aerodynamic air gaps created during the extension aspect of deployment of the flaperon  24  is coupled to the structure of the cam track mechanism  42  to assure desired angular positioning relative to the wing  10  and the flaperon  24 . 
     Several challenges are presented by such structures adapted to satisfactorily accommodate both angular and translational motion, including the need to assure requisite fail-safe strength and robustness under occasional extreme loads, such as those associated with turbulence and other phenomena routinely encountered in flight. As such, the cam track mechanism  42  includes relatively heavy cam tracks  44  that define paths for cam track rollers  48  that are directly secured to roller links  46 . Use of the cam track mechanism  42  has also necessitated the use of a technology called “fusing”, for assuring safety in the event of “jamming” of any of the track rollers  38 . Since jamming is an issue to be avoided at all costs, at least two roller links are typically riveted together in a cam track-style mechanism  42  ( FIG. 3 ) for appropriate safety redundancy. Such links are designed to fail in a predictable manner, necessitating additional weight that would be preferably avoided. 
     Thus, it is desirable to provide novel aerodynamic gap control structures to accommodate both angular and translational movements of flaperons, but wherein such structures can retain robustness and yet be lighter in weight, in the face of increasingly stringent aircraft design requirements. 
     SUMMARY 
     In accordance with one aspect of the present disclosure, an aircraft wing configured to be fixed to and extend from an aircraft fuselage, the wing having a leading edge and a trailing edge. The trailing edge includes an attached aerodynamic primary control device, the movement thereof subject to an input controller. A moveable aerodynamic cove lip door is proximal to the primary control device, though separately attached to the trailing edge. 
     In accordance with another aspect of the present disclosure, an actuator is in communication with the control device, and an aircraft input controller is in communication with the actuator, and movement of the control device is subject to the actuator via the input controller. 
     In accordance with another aspect of the present disclosure, a bell crank mechanism is coupled to a secondary control device, such as a hinge panel, and configured to link movement of the bell crank directly to movement of the secondary control device. 
     In accordance with yet another aspect of the present disclosure, a cove lip door mechanism controls movement of the cove lip door as an indirect function of movement of the primary control device. 
     The features, functions, and advantages disclosed herein can be achieved independently in various embodiments or may be combined in yet other embodiments, the details of which may be better appreciated with reference to the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a fragmentary plan view of a wing of a commercial aircraft configured in accordance with the related art. 
         FIG. 2  is a fragmentary schematic elevation view of an inboard aileron of the commercial aircraft of  FIG. 1 . 
         FIG. 3  is a fragmentary elevational view of a cross-section of an inboard flap of the commercial aircraft of  FIG. 1 . 
         FIG. 4  is a fragmentary elevational view of a cross-section of an inboard flap and hinge panel constructed in accordance with a described embodiment of the present disclosure. 
         FIG. 5  is a fragmentary elevational view of a cross-section of the same inboard flap and hinge panel constructed in accordance with a described embodiment of the present disclosure, albeit with the flap shown in a different position. 
         FIG. 6  is a perspective view of the same inboard flap of  FIGS. 4 and 5 , but including a view of an associated cove lip door. 
         FIG. 7  is a perspective schematic view of the same inboard flap of  FIGS. 4 and 5 , but including a view of the flap actuator structure in relation to the flap lip. 
         FIG. 8  is a perspective schematic view of the same inboard flap and flap actuator structure of  FIG. 7 , albeit with the flap shown in a different position. 
         FIG. 9  is a flowchart depicting relationships among aircraft components of the present disclosure. 
     
    
    
     It should be understood that the drawings are not necessarily to scale, and that the disclosed embodiments are illustrated only schematically. It should be further understood that the following detailed description is merely exemplary and not intended to be limiting in application or uses. As such, although the present disclosure is, for purposes of explanatory convenience, depicted and described in only the illustrative embodiments presented, the disclosure may be implemented in numerous other embodiments, and within various other systems and environments not shown or described herein. 
     DETAILED DESCRIPTION 
     The following detailed description is intended to provide both apparatus and methods for carrying out the disclosure. Actual scope of the disclosure is as defined by the appended claims. 
       FIG. 4  is an elevational cross-section view of an inboard flap  124 , as a primary flight control device, constructed in accordance with one described embodiment of the present disclosure. The inboard flap  124 , shown in an upward position while functioning as a flaperon, is relatively movable with respect to the trailing edge  132  of the wing  110 . A bell crank mechanism  150  effectively comprises a pair or series of four-bar linkages configured to control movement of a secondary flight control device, such as a separately movable hinge panel  140 , thus eliminating the need for the related art cam track mechanism  42  described above. 
     Continuing reference to  FIG. 4 , a support header (also generally and commonly called a rib)  160  is a vertically oriented structural member within an interior space  161  of the flap  124 . Typically there are a number of such support headers fixed in a parallel, spaced array. In the described embodiment the wing  110 , at least two of such support headers  160  of each wing  110  includes an integral flap extension flange  162 . Each of the flap extension flanges  162  is coupled directly to a single bell crank mechanism  150 . Both bell crank mechanisms  150 ,  152  ( FIG. 6 ) of each wing  110  operate in concert, as will be appreciated by those skilled in the art. As such, only one of the two mechanisms, i.e. bell crank mechanism  150 , will be described herein. 
     The flap extension flange  162  is coupled via a coupling joint  164  to a bottom or flap link  166 . At the forward end of the link  166  is a coupling joint  168  which pivotally secures the link  166  to a center link  170 . At an intermediate portion thereof, the center link  170  is fixed to and rotates about a fixed coupling joint  172 , which is secured to a support header  174 , which is an integral part of the trailing edge  32  the wing  110 . 
     An upper coupling joint  176  of the center link  170  is configured to couple with an upper link  178 . It will be appreciated that the latter provides a first, indirect connection to the hinge panel  140 . The upper link  178  includes a forward coupling joint  180  adapted to connect directly to hinge panel link  182  (shown in phantom, since hidden behind support structures within the trailing edge  132 ). A forward coupling joint  184  of the hinge panel link  182  provides a direct connection to a hinge panel support header  186 , a structural support member of the hinge panel  140 , as depicted. 
     The described elements, including all links and coupling joints (i.e., connections) are maintained in  FIG. 5 , wherein the inboard flap  124  is shown deployed downwardly, in either a flap or flaperon configuration, as already described. The center link  170  is pivotally connected to, and translationally fixed to the trailing edge  132 , for supporting only pivotal movement of the center link relative to the trailing edge. For this purpose, the center link  170  has three connecting joints i.e. coupling joint  168  at one end thereof, shared with the flap link  166 , the fixed coupling joint  172  at its center, about which it is pivotally secured to the support header  174 , and the upper coupling joint  176 , shared with the forward hinge panel link  182 . 
     Those skilled in the art will appreciate that in order to support slaved movement of the bell crank mechanisms  150 ,  152  with respect to movement of the flap  124  relative to the trailing edge  132 , there must be an additional pivotally fixed reactive connection between the flap  124  and the trailing edge  132 . 
     Referring now to  FIG. 6 , a perspective view of the flap or flaperon  124  depicts the use of dual bell crank mechanisms  150  axially offset from a pair of spaced cooperating actuators  200  and  202 . Those skilled in the art will appreciate that the actuator, at least in this described embodiment, is a device responsible for actual deployment, hence movement of the flap  124  relative to the trailing edge  132  between its limits, as shown in  FIGS. 4 and 5 . As shown, the actuators  200 ,  202  include separate direct connections to the flaperon  124 , to support primary flight control via the actuators  200 ,  202 . 
       FIG. 6  also depicts a so-called cove lip door  270 . In addition to the described hinge panel  140 , the cove lip door is another aerodynamic feature that may be associated with the flaperon  124 . The cove lip door  270 , essentially a miniature wing-like structure, shown only schematically (thus not revealing its reactive pivotal connection to the trailing edge  132 ) can provide real-time aerodynamic gap control management, and may be configured to be controllably displaced relative to the flaperon  124  via both rotation and translation motions to manage any air gaps created by the extension (i.e. translational) and rotational movement of the flaperon  124 . For this purpose, a cove lip door mechanism  300  can be configured to control movement of the cove lip door  270 , and essentially to slave such movement to the movement of the flaperon  124 . 
     Referring now to  FIG. 7 , one end of the actuator  200  is shown coupled to an actuator pivot link  250  while the flaperon  124  is in a stowed position, such as during a cruise phase of flight. The actuator pivot link  250  has a first end  252  and a second end  254 . The first end  252  thereof is secured to the actuator  200  via joint  256 , the latter coupling the actuator  200  directly to the actuator pivot link  250  to support pivotal motion of the two members relative to the other. 
     The second end  254  of the actuator pivot link  250  contains a joint  258  that is fixed to the trailing edge  132 , and thus allows the actuator pivot link  250  to pivot about the trailing edge  132  at the joint  258 . Movement of the cove lip door  270  is controlled by such pivotal action of the actuator pivot link  250 . For this purpose, a cove lip door drive arm  260  is secured to a drive link  262 , having first and second jointed ends  264 ,  266 , respectively, as shown. At the first jointed end  264 , the drive arm  260 , is secured to the actuator pivot link  250  at a position intermediate of respective first and second ends  252 ,  254 , to provide a location about which the drive link  262  pivots on the actuator pivot link  250 . On the other hand, a cove lip door hinge  268  at the jointed end  266 , is configured to connect directly to the cove lip door  270 , and thus pivots about the first jointed end  264 . 
       FIG. 8  depicts the flaperon and cove lip door structures in a flaperon “up position” such as during cruise when the flaperon is operating as an inboard aileron, described above. All of the aforementioned structures have connective relationships and associations as described, albeit the cove lip door  270  is shown in a different position relative to the flaperon  124 . 
       FIG. 9  provides a flowchart depicting the relationship of the aircraft input controller  190  to the actuators  200 ,  202  (two per wing in the disclosed embodiment). To the extent that the actuators are directly connected to and engaged with the cove lip door mechanisms  300 ,  302  (two per wing in the disclosed embodiment), and are thus configured to move respective cove lip door actuator pivot links in the described manner, it will be apparent to those skilled in the art that primary or direct control of the trailing edge device  124  is an intended response of the aircraft input controller  190 , as described in detail herein. On the other hand, the input controller  190  is configured to provide a secondary, indirect, or slaved control of the cove lip door  270 , thus causing a desired follower movement of the cove lip door relative to any direct actuation of a trailing edge device, such as the flaperon  124 . 
     Finally, a method of slaving motion of a cove lip door to that of a trailing edge device may include steps of providing a cove lip door control mechanism for an aircraft wing, the wing configured to be fixed to and extend from an aircraft fuselage, the wing having a leading edge and a trailing edge. The steps may include providing a primary aerodynamic control device and attaching the primary control device to the trailing edge and providing an actuator configured to operate the control device. The steps may further include providing an aircraft input controller configured to move the actuator, wherein movement of the primary control device is subject to the actuator via the input controller. Finally, the steps may further include providing a bell crank mechanism coupled to a secondary control device, and configured to link movement of the actuator directly to movement of the secondary control device, and providing a moveable aerodynamic cove lip door proximal to the primary control device, the cove lip door separately attached to the trailing edge for the actuator to also control movement of the cove lip door as an indirect function of movement of the control device. 
     Those skilled in the art will appreciate that the structures described, including the actuator pivot link  250 , drive arm  260 , and drive link  262 , as associated with the cove lip door  270  may offer numerous benefits over related art. Moreover, by use of the bell cranks  150 ,  152  for control of the flaperon hinge panel  140 , not only is a cam track weight penalty avoided, but above-described fusing requirements can be avoided as well. With particular respect to use of the bell cranks, additional benefits are reduction in manufacturing complexity associated with cam track mechanisms, and avoidance of issues inherent to cam track mechanisms, including gouging or fracture damage, and/or imposition of increased loading on structures, from deleterious accumulations of wear particle debris within cam track surfaces, for example. 
     In addition, the disclosure may also cover numerous additional embodiments. For example, the lengths of each link may be adjusted to support various aerodynamically distinct flight circumstances and/or surface geometries for minimizing interference drag coefficients, including those related to skin friction, parasitic and separation drag, as well as wave drag. As such, particular forms and shapes of the links, for example, may be adjusted to optimize desired gaps controlled by the cove lip door for optimizing flight performance characteristics.