AIRCRAFT TRAILING EDGE FLAP APPARATUS

Abstract: A flap apparatus for an airfoil assembly in­ cluding a first or main flap and a second or aft flap positioned generally rearwardly from the first flap; means for supporting said flaps to allow movement thereof between a first forward stowed position wherein said flaps are generally aerodynamically aligned for cruise mode of operation, a second intermediate position and a third position wherein said flaps are displaced rearwardly and downwardly and actuator means for repositioning said flaps assembly between the first, second and third positions, said actuator means comprising a first linkage means operatively connecting said first flap and second linkage means con­ necting said second flap to a single actuator arm, said first linkage means connected to said actuator arm at a first connector location, said second linkage means con­ nected to said actuator arm at a second connector location said first connector location located radially inboard of said second connector location so that rotation of said actuator arm causes said second connector location to rotate through a larger radius than said first connector location to move said first flap and said second flap between the first, second and third position.

Description: The present invention relates generally to aircraft trailing edge flaps and flaps sequencing apparatus, and more particularly to a flap apparatus as defined in the introductory part of claim 1. A flap apparatus of this kind is known from US-A-2 146 014. By having the first and second linkage means connected to a single actuator arm, the necessary coordination between the movements of the two linkage means is obtained in a very simple and straightforward way. The fargoing simplicity of the device shown in said publication, however, will lead to not optimum positioning of the flaps in the several operational positions. Accordingly it is an object of the present invention to provide an improved wing flap assembly of the kind set forth above, which has a desirable balance of features relative to simplicity, reduced weight and ease of operation. According to the invention this is achieved with the features as defined in the characterizing part of claim 1. It has appeared that with the flap apparatus according to the invention effective positioning of the flaps can be obtained. These and other objects and advantages of the present invention will become more readily apparent upon reading the following detailed description and upon reference to the attached drawings, in which: Fig. 1 is a side view of a single arm rotary actuator, linkage assembly, support assembly and flap assembly in the stowed configuration; Fig. 2 is a side view of the single arm rotary actuator, linkage assembly, support assembly and flap assembly in one of a plurality of possible intermediate configurations; and Fig. 3 is a side view of the single arm rotary actuator, linkage assembly, support assembly and flap assembly in the fully extended configuration. While the present invention is susceptible of various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. Detailed description of the invention Referring to figs. 1 through 3, there is shown a wing indicated at 20, a dual flap assembly indicated at 32, a single arm actuator assembly indicated at 200, a linkage assembly indicated at 62 and a support assembly indicated at 63. Briefly, flap assembly 32 is repositioned between a stowed configuration illustrated in fig. 1, one of may possible intermediate configurations illustrated in fig. 2, and a fully extended configuration illustrated in fig. 3, by single arm rotary actuator assembly 200 which rotates in a counterclockwise direction to propel a mobile carriage 100 and various pivotally mounted linking arms, drive rods, connecting arms to reposition flap assembly 32 from the stowed position to the intermediate and fully extended positions. Referring now to figs. 1, 2 and 3, there is shown a trailing edge portion of an aircraft wing indicated at 20 including an upper surface 22, and a forward trailing edge portion 26. In order to provide additional aerodynamic lift to wing 20 during takeoff, landing or other slow speed flight conditions, a trailing edge flap assembly indicated at 32 is located at rearward portion of wing 20. In order to reposition flaps 36, 50 between various flight configurations, there is shown a linkage assembly 62 including a carriage 100 slidably supported on a track 66 to allow for movement of a carriage 100 between wing forward trailing edge portion 26 and wing aft trailing edge portion when carriage 100 is propelled by rotary actuator 200. Carriage 100, including a forward end 102 and a rearward end 104, is connected to main flap 36 via a support member 106 which is rigidly affixed at one end thereof to a forward portion of main flap 36 and which extends downwardly from the main flap. The distal end of forward support member 106 is pivotally connected to carriage aft end 104. The term "pivot connector" used in the present application may comprise a ball and joint fitting, bearing, or other pivotal apparatus which is known to those of ordinary skill in the art. Fore and aft movement of carriage 100 is guided by track 66 which has an "I" frame configuration; track 66 sloped slightly downwardly in the fore to aft direction to provide sufficient clearance between main flap 36 and wing 20 when main flap 36 is repositioned from the stowed configuration to an intermediate or landing configuration. The top or track 66 includes a support flange 103 which is engaged in the vertical direction at forward carriage portion 102 by two upper carriage roller having respective axes of rotation lying in the vertical plane and located at opposite sides of flange 103, and by two lower carriage rollers having respective axes of rotation lying in the horizontal plane. The rearward portion 104 of carriage 110 includes a second set of vertical rollers. The lower carriage rollers sized larger than upper rollers due to their proximity to main flap support member 106 and the aerodynamic forces acting thereon. It should be appreciated that flaps 36, 50 do not remain nested during extension and retraction, but rather begin to separate immediately as rotary actuator 200 begins to rotate counterclockwise from the eight o'clock position, thus providing a double slotted flap configuration. Rotary actuator 200 comprises an actuator arm 202 driven by a torque shaft 131 engaging actuator arm 202 at the proximal end thereof. In order to propel carriage 100 along track 66, one end of a drive rod 206 is pivotally connected to rotary actuator arm 202 by pivot connector 208, the other end of drive rod 206 pivotally connected to a forward portion 102 of carriage 100 by a pivot connector (not shown). Counterclockwise rotation of rotary arm 202 repositions aft flap 50 via a drive rod 210 pivotally connected at one end to linking arm 142 by a pivot connector 143, drive rod 210 pivotally connected at the other end thereof to the distal end of rotary arm 202 by pivot connector 212 located radially outboard from pivot connector 208 such that pivot connector 212 is rotated through a larger radius with respect to torque shaft 131 than is pivot connector 208. Linking arm 142 is pivoted about pivot connector 145 to pivot aft flap 50 about pivot connector 156 via a connecting arm 144. The connecting arm 144 pivotally connected to aft flap support member 90 at pivot connector 156 and to linking arm 142 about pivot connector 152. Drive rods 206, 210 are pivotally connected to rotary arm 202 at opposite sides thereof to provide an operating clearance between drive rod 206 and drive rod 210. A flairing 96 which surrounds linkage assembly 62 and support assembly 63 provides a clean aerodynamic surface there around. Operation of rotary actuator 200, linkage assembly 62, support assembly 63, and flap assembly 32 is as follows: As rotary arm 202 rotates in a counterclockwise direction, carriage 100 is propelled along track 66 at a slower rate than drive rod 210 rotates linking arm 142 about pivot connector 145 because pivot 208 is rotated through a smaller radius than pivot connector 212. Pivotal movement of linking arm 142 in turn drives a connecting arm 144 to reposition aft flap 50 at a faster rate than linear movement of carriage 100 causes rotation of main flap 36 around pivot connectors 80, 82 causing aft flap 50 to be repositioned at a faster rate relative to main flap 36. The relative positions of pivot connectors 208, 212 with respect to each other determine the relative rate of movement of aft flap 50 with respect to main flap 36. Increasing the radial distance between pivot connectors 208, 212 increases the relative rate of movement of aft flap 50 with respect to main flap 36, whereas decreasing the radial distance between pivot connectors 208, 212 decreases the relative rate of movement of aft flap 50 with respect to main flap 36. Increasing the radial distance of pivot connectors 208, 212 with respect to torque shaft 131, increases the rate of movement of flaps 36, 50 with respect to wing 20. It should be appreciated in the present invention that the majority of the aerodynamic load forces are centered about a load vector directed through the aft portion of main flap 36 and the distal end of track mounting member 70 when flap assembly 32 is in the extended position illustrated in figs. 2 and 3. Therefore, the primary aerodynamic load bearing members in the present invention are track mounting member 70, linking arm 76, main flap support 72, and aft flap support member 90. In addition, the simplicity of design and reduced profile of rotary actuator 200, linkage assembly 62, and support assembly 63 results in reduced overall aerodynamic drag, reduced gross weight and more reliable operation. Furthermore the simplicity of rotary actuator 200 using differential radial distances along rotary arm 202 to reposition flap assembly 32 results in an effective trailing edge flap assembly.

Claims: A flap apparatus for an airfoil (20), said airfoil having upper (22) and lower surfaces, a forward portion (26) and a rearward portion, said flap apparatus comprising: a.a flap assembly (32) located proximate to the rear portion of said airfoil (20), said flap assembly (32) including a first or main flap (36) and a second or aft flap (50) positioned generally rearwardly from said first flap (36); b.means for supporting (63) said flap assembly (32) to allow movement of said flaps (36, 50) between a first forward stowed position wherein said flaps are generally aerodynamically aligned for cruise mode of operation, a second intermediate position wherein the flaps (36, 50) are displaced downwardly and rearwardly from the first position, and a third position wherein said flaps (36, 50) are displaced rearwardly and downwardly from the second intermediate position; and c.actuator means (200) for repositioning said flap assembly (32) between the first, second and third positions, said actuator means (200) comprising a first linkage means (62) operatively connecting said first flap (36) to an actuator arm (202) at a first connector location and second linkage means (210, 142, 144) connecting said second flap (50) to the actuator arm (202), at a second connector location (212), said first connector location (208) located radially inboard of said second connector location (212) so that rotation of said actuator arm (202) causes said second connector location (212) to rotate through a larger radius than said first connector location (208) to move said first flap (36) and said second flap (50) between the first, second and third position, characterized in that said first linkage means (62) comprises: a.a mobile member (100) slidably engaged to said airfoil (20); and b.a drive rod (206) operatively connected to said actuator arm (202) and to said mobile member (100), respectively, the rotation of said actuator arm (202) moving said mobile member (100) to move said first flap (36) between the first, second and third positions. The flap apparatus according to claim 1 characterized in that said flap support means (63) comprises: a.a support member (90) extending downwardly from said second flap (50); b.a support member (72) extending downwardly from a rear portion of said first flap (36), said first flap support member (72) operatively connected to said second flap support member (90); c.a mounting member (70) rigidly secured to said airfoil (20), said airfoil mounting member (70) extending downwardly therefrom; and d.an arm (76) operatively connected to said airfoil mounting member (70) and operatively connected to said first flap support member (72) respectively. The flap apparatus according to claim 1 or 2 , characterized in that a.said airfoil (20) includes a linear track (66) positioned substantially in the fore and aft direction relative to said airfoil (20); and b.said mobile member (100) comprising a plurality of wheel members rotatably mounted to a frame member in the horizontal and vertical planes, said wheel members engaging said track (66) to secure said mobile member (100) to said track in a horizontal and a vertical direction. The flap apparatus according one of the claims 2 or 3 , characterized in that said airfoil mounting member (70) extends downwardly and rearwardly from said track. The flap apparatus according to one of the preceding claims, characterized in that said second linkage means comprises: a.a linking arm (142) operatively connected to said first flap (36); b.a connecting arm (144) operatively connected to said second flap support member (90) and to said linking arm (142); and c.a drive rod (210) operatively connected to said actuator arm (202), said drive rod (210) operatively connected to said linking arm (142) between the connection point (145) of said linking arm (142) to said first flap (36) and the connection point (152) of said linking arm (142) to said second flap connecting arm (144), the rotation of said actuator arm (202) causing said drive rod (210) to move said linking arm (142) which in turn causes said connecting arm (144) to move said second flap (50).

Inventors: FRANKLIN, WILLIAM L., WEILAND, RICHARD H.
Applicants: THE BOEING COMPANY
Application year: 1985
Main classification: B64C9
IPC codes: B64C9