WO2003013956A1 - Flap deployment mechanism with swing arms - Google Patents

Abstract

The spar (4) of the wing has a support bracket (27) on which the flap arm (6) is attached at its proximal end (10). The flap arm is connected to the flap by a flap extension (39) fixed to the flap (5) and parallel to longitudinal axis. There are a number of flap arms on the spar. Each of these flap arms has similar lengths and directional orientation of the sector swept by them. All of them move through a sector of ninety degrees, are always parallel to each other at any time and when the flaps move they have a parallelogramming effect. The angulating mechanism (59) on the fixed end of flap arm moves the flaps to make an angle with plane of wing (24) and sequencing mechanism (61) on the moveable end gives a pre-programmed movement to the flaps.

Description

FLAP DEPLOYMENT MECHANISM WITH SWING ARMS

Technical field: An aircraft of any type, can fly at various airspeeds from its maximum cruise airspeed when its cruising, it also flies at lower airspeeds required for take off and landing and also can fly at miriimum airspeed called as stalling speed. The various parts of the aircraft, which consists of fuselage, wings and flight controls, are designed to fly at the rriaximum cruise speed of the aircraft. So when the aircraft airspeed starts reducing below this maximum cruise speed during landing, the design of wings does not allow it to sustain flight. The coefficient of lift of aircraft wings increases with increase in the air speed, the total area of the wing ,which is the combination of spar and chord, and camber of the airfoil surface of wing which increases its angle of attack. When the aircraft is cruising, it flies at a certain angle of attack but since the air speed is high it is able to sustain the flight. During landing the air speed reduces but the angle of attack is the same so there is a loss of lift and it is unable to sustain flight. So, to increase the coefficient of lift at low speeds we increase the area of the wing. We increase the area by increasing the chord because it is not possible to increase the span of the wing. And we also increase the camber of the wing to increase its angle of attack. To increase the coefficient of lift, we place an auxiliary aerofoil surface called as flaps on the leading edge and trailing edge of the wings. The flaps have various positions when they operate, but we study only three positions. At cruise position, they are completely faired with the wings so that it does not cause any turbulence and drag. They are shaped in such a way that they take the shape of the wing when fully retracted in cruise. When flaps operate at take off positions the flaps separate out and come out as well as down. This increases the area as well as camber of the wing, which increases the coefficient of the lift of the wing and permits lower speed for airplane rotatioa At landing position the flaps move still further and come out as well as move downwards. When they reach the full down position, air gaps or slots are created between flaps and wings. The wings are at high angle of attack so high pressure air from bottom of wing mixes with the low-pressure air from top, through these air gaps and this action prevents a stall of the wing. The coefficient of lift of the wing still increases and the airflow does not break and it flows smoothly without any turbulence..

The kreuger flap on the inboard side of the wing leading edge is not discussed here, as it does not form a part of this invention. This invention pertains to the support and actuation system of the flaps. Hence it does not cover the cross sectional shape (aerofoil shape) or the overall shape of the flap. But, the invention does cover the shape given to one side of the flap(the breadthwise side of the flap) as explained further in plan-form shape of the flap under the topic "Disclosure of the invention".

Background art: We will discuss in brief the leading and trailing edge flaps system, which is used, on any of the passenger transport category or heavy aircraft. This is the most conventional way of flap construction for these aircraft. With a little difference the type of components and their function is basically same for all aircraft. The trailing edge flaps which are double slotted flaps consisting of fore flap and aft flap, where on each wing they are in two sets which are inboard and outboard. There are a total of four trailing edge flaps. There are a total of eight flap supports, of which four are on each wing. There are two flap supports each for the inboard and outboard flaps. Each of these flap support has a flap sequencing track of T section on which the flap carriage slides with help of bearings. The function of the flap track is to support the weight of the flap and allow for its movement. The flap actuation system consists of screw jack. Here the ball screw rotates via the universal coupling to move the ball nut and the ball nut is connected to the flap carriage via a gimbal, which moves to move the flaps. The transmission assembly consists of a gearbox, which consists of a set of gears that change the direction of rotation of the torque tube to move the screw jack. The torque tube runs through the entire length of the flaps behind the rear spar and also through the center on the rear bulkhead of the wheel well. A hydraulic motor in the wheel well drives the torque tube and it drives all transmission gearboxes, which moves the screw jacks. Its function is to allow the flaps operate synchronously and symmetrically on both sides of wing. The aft flap will also drive on the track and bearing assembly inside the fore flap. The apt flap operates in proportion to the fore flap, by mechanical linkages connected to the fore flap. The flap skew sensor is an electrical flap position transmitter, operated by mechanical linkages to the fore flaps. All these transmitters act as syncro sensors, which measure if all the eight screw jacks are moving synchronously. There are a total of eight leading edge slats on the aircraft and on each wing there are four slats on the outboard side of aircraft. Each slat has two main tracks, which ride on four roller bearing in the structure. There are also two auxiliary tracks on each slats. The anti-ice air supply duct passes through the entire length of the slats along the front spar on both wings. This hot anti- ice air is passed through telescopic ducts to the individual heating duct placed inside each slat. The hot air passes through the heating duct inside the slats. Now this air passes through a narrow passage between the external skin and the partition just behind it. In doing so, it gives its heat to the skin and it gets hot. The air passes out of passage and accumulates in the cavity of slat from where it is exhausted overboard through the holes at the bottom of the slat.

We will discuss some of the disadvantages of this conventional flaps system used on passenger transport category or heavy aircraft. In each of the flap support we have a number of components; which are flap track, flap carriage, screw jack, transmission and all related mechanical assemblies. Here each of these components has only one particular functioa If we consider all the eight flap supports the total number of components will be too much There are many sequencing tracks such as main track, aft flap track and auxiliary tracks. There are complex mechanical linkages for flap skew system and aft flap mechanism In each of these flap support there is an individual flap actuation system provided which is screw jack and transmission, which seems to be unnecessary. There are many joints in this system due to its complexity and many are eccentric joints or sliding joints like the flap track and aft flap track.

Due to many number of joints, we have many joints, which are to be lubricated and sometimes lubrication becomes difficult as the joints get seized or there is no proper access for hibricatioα We have seen that in only one flap support there so many components. So if we analyze the total weight of all the eight flap supports, it will be too high. This extra weight acts as a dead weight on the aircraft during cruise flight, as the flaps are used only during take-off and landing. Hence all this leads to higher fuel consumption. The flap supports will be placed below the wing surface, so they are a source of constant drag to the aircraft during cruise flight. This gives higher fuel consumption. The direction of rotation of the torque tube is changed by the transmission gearbox to rotate the screw jack since there is a change in the direction of rotation brought about by the transmission gearbox, there is a loss of power supplied by the torque tube. The aft flap is operated means of complex mechanical linkages connected to the fore flap. Mechanical linkages connected to the fore flap operate the skew sensor transmitter. The anti-ice hot air supply duct passes through the entire length of the slats, on both sides, near the front spar. It supplies air by telescopic ducts to heating ducts in each individual slat. Each leading edge slat has two main tracks and two auxiliary tracks and their respective bearing assemblies. Disclosure of the invention: Here we briefly summaries the new flaps actuation system as disclosed in this invention and which can be used on passenger transport category aircraft.

There are flap arms, which are joint to the spar and it forms the center around which the arm rotates. The extreme end of flap arm is connected to the flap on the flap extension, which is rigidly attached to the flaps. The flap arms move a sector of 90 degrees angle, where they fold to retract and unfold to extend the flaps. The axis of rotation passing through center will be parallel to vertical axis. The sector swept by the flap arm during its movement will be such that it has a particular direction of orientation. When the flap arms move to move the flaps, they also move the flaps sideways or laterally, which is called lateral displacement of the flaps and is an inherent characteristics of this kind of flaps. The shape of the flap arm is rectangular and they have certain length and certain thickness. The straight shaped flap arm is used for swept-back wings and 'L' shaped flap arm is used for rectangular wings. The combination of flap arm and flap extension gives us less drag. The plan-form shape of the flap (as seen from top) is not rectangular in shape, but is modified such that one side (breadth) is at an angle and the other side (breadth) is at a right angle to the length of the flap. Due to this there is no void space formed, as the flap gets properly accommodated inside the wing when retracted. All the flap arms operate synchronously or in phase (they are parallel to each other at all times), to move the entire body of the flaps. We see that there is a paraUelograrnrning effect as all the flap arms move, as they seem to be opening and closing the imaginary parallelogram. The angulating mechanism is situated on the fixed end or center of the flap arm around which it rotates. The axis of rotation of this mechanism is kept such that it is inclined so that it makes a certain angle with the vertical axis and also makes an angle of 45 degrees with both longitudinal and lateral axis. Due to this when the flap arm rotates it also makes an angle with the plane of the wing, which is proportional to the angle of inclination of axis of rotation. This is also the basic function of angulating mechanism. The sequencing mechanism is positioned at the free end or extreme end of the flap arm, which moves around the center. The function of it is to provide proper sequencing and pre-programmed movement to the flaps. It consists of a tapering end and swiveling joint. The tapering end is responsible for the sequencing given to the flaps. The angle at which this tapering end is oriented towards, determines the types of sequencing required. The function of swivelling joint is to swivell around itself and allow relative movement between the tapering end side and flap extension which is fixed. It consists of a male and female part which are screwed on to each other and connected to the tapering end side. The two flaps on each side of wing which are inboard and outboard flaps, are separated by some distance. Now to interconnect both of them we have an additional inter-connect tie rod. Due to this both the flaps on each wing will operate synchronously with each other. The most inboard flap arm will act as an actuating flap arm, which has an actuating lever added to the flap arm This lever may be moved by any actuating system as screw jack or hydraulic actuator.

Flap position transmitters or skew sensors sense the movement of each flap arm, where they act as syncro sensors and sense the mismatch between the movement of all the flap arms. The skew sensors are placed at the top of the support bracket of flap arm and senses the movement of the flap arm at its axis of rotation Due to this there are no mechanical linkages required. The aft flap also has the same operating principles and components as the fore flap. It has similar kind of flap arms, sequencing mechanism and flap extension as the fore flap, but only difference is that for the aft flap they are quite small in size. The aft flap is operated in a similar way as the fore flap, by mechanical linkages to the fore flap. All these linkages pass from the sides or outside of the flap body and not inside its body. The anti-ice heating duct inside the slat will be joint end to end by an coupling joint, so that the hot air can pass through the entire length of the duct. The anti-ice air supply duct runs through a short length at the inboard. The connecting duct will be placed on the most inboard side after the actuating flap arm. It is circular in cross-section and operate in the same way as the flap arm, where its axis of rotation will be same as that of angulating mechanism.

We will study the distinct advantages of the new system for flap actuation as compared to the disadvantages of the conventional system given in "Background art". The flap arm in this system performs the function of supporting the weight and moving the flaps. The flap arm is rnanufactured so that it has an inbuild angulating mechanism and a tapering end. The tapering end when connected to the swivelling joint forms the sequencing mechanism. Hence the flap arm itself performs many multipurpose functions and so we have a very few components. The flap arm will move around the center, to fold and unfold to move the flaps in and out of the wing. Since the flap arm itself performs the function of angulating and sequencing, there are no complex linkages or sequencing tracks. There is only one actuation system in form of a screw jack or hydraulic actuator on each wing for actuating either leading edge or trailing edge flaps. The flaps will be interconnected by a link called as inter connecting link, so that the flaps move synchronously. There are a less number of joints and each joint will rotate in one and only one axis of rotation and there are no sliding joints. Due to this the joints can be made with more thicker and bigger components, so that the assembly has less play between the components and is highly robost.

For lubrication, the joints are provided with internal drilled passages and gaps are provided between the screw threads of the swivelling joint. When attempted to lubricate, both the ends of the joint or the entire screw threads in case of the swivelling joint are lubricated at one time only. Hence it is not required to lubricate each portion of joints seperatery. Since the number of components in the assembly are reduced, there is a very good weight savings. So ultimately we can gain in lower fuel consumption. Since the flap arm fold and unfold is the process of flap extension and retraction. When retracted the flap goes inside the wing body and nothing comes out of the wing surface, hence we have a smooth wing surface. This causes less drag during cruise flight and helps reduce fuel consumptioα The torque tube runs only till half the length of the trailing edge flaps (that is till the inboard flap), to drive the screw jack which is placed inline with it. Hence the screw jack can make the most efficient use of the power delivered by the torque tube. The aft flap is operated by a simple mechanical linkage from the fore flap. This linkage passes from outside the flap body from its sides and not from inside it, hence we can have a solid flap body without any holes or cavities made for passing the aft flap linkages. The flap skew sensor are small electrical position transmitters which are placed on the top face of the mounting bracket around which the flap arm rotates. There are no mechanical linkages required for this. It senses the movement between the rotating flap arm with respect to the fixed bracket. The anti-ice air supply duct passes only a short distance on inboard side of the slats. It supplies air to the connecting duct, which passes the air to the heating duct inside the slat.

Basic concept: To understand the basic concept of the new system we have to consider an simple aircraft with a rectangular shaped wing 12, having a flap 5 at the trailing edge only. Here only one flap is shown for the simplicity of explaination. Figure 1 shows the perspective view of the type of wing with flaps shown in three different positions which are retracted 19, intermediate 20 and extended 21. An arrow 8 points to show the top view of figure. Figure 2 shows the top view and the flap in rectangular in shape as seen from the top view.

The flaps 5 are connected to the spar 4 of the wing by flap arms 6. The flap arms 6 are flat, straight, have definite length and certain amount of thickness. They are basically rectangular in shape and also in cross-section. They are mounted such that their breadth is parallel to vertical axis 3 and length is parallel to plane of the wing 24. The main function of the flap arm is to support the entire weight of the flap and transfer this load to the spar. The other function being to allow the movement of the flap by folding 22 and unfolding 23 itself and also to allow the sequencing movement of flaps. They are connected to the wing spar 4 by the spar mount 10 and to the flap 5 by a flap mount 11. They are bolted to these mounts by standard hardware such as bolts and nuts. The flap arm 6 during their movement will move to sweep an sector of 90 degrees angle as in 14. The flap arm will fold 22 inside the wing when flaps are retracted 19 and they unfold 23 when flaps are extended 21. The axis of rotation 26 around which this flap arm 6 rotates is parallel to vertical axis 3. Since, the flap arm 6 moves through sector of 90 degrees angle, the flap arm is so placed or oriented that its parallel to lateral axis 1 in retracted position 19 and perpendicular to it in extended position 21. Hence we can see the directional orientation of this sector of the flap arm 6 as shown in arrow 28, which points downwards and is unfavourable. Due to the parallelogramming effect of the flaps and the unfavourable directional orientation 28 of sector swept by the flap, we have a very high lateral displacement 31 or the sideways movement of flap along the lateral axis 1. Due to the straight shape of the flap arm, the actual amount of portion of flap arm 35 which obstructs the airflow and causes drag is very high. Hence we get a high amount of drag from flap arm. Due to the lateral displacement of the flaps 31, there is a void space 7 created when flaps are retracted. This space must be kept to cater for lateral movement of flaps and it does not give aerodynamic smoothness to the wing.

All the flap arms 6 operate syncronously so that at any given position they are parallel to each other as in 25 .Consider the parallelogram formed by points 15,16,17,18. Now when the flap moves, there is a parallelogramming effect due to the opening and closing of the parallelogram and hence the system is named as parallelogramming flaps. In addition to this all flap arms have the same lengths. They move to sweep a sector of equal angles, which have the same directional orientation.

Application of the basic concept: We now study the practical application of the basic concept of the flaps system on various kinds of aircraft wings. We apply this concept on a rectangular shaped and swept back wings. Figure 3 shows the practical application of the concept on an swept back wing 13, which gives the perspective view of the wing with both leading edge 41 and trailing edge 42 flaps. The above concept can be used for swept back wings with any angle of sweep back. Figure 4 shows the top view and figure 5 shows the side view of the above perspective view. Figure 6 show application of concept on rectangular shaped wing 12, which gives the top view of the wing only. The above concept can be used on rectangular wing or any kind of wing having some portion straight or parallel to lateral axis 1. Here the perspective view and side view are not shown as they will be basically the same as for the swept back wing.

The flap arms 6 over here are connected to the spar by a support bracket 27 instead of the spar mount and this forms the center of imaginary circle around which the flap arm moves to sweep any particular sector of any angle. Here the flap arm moves sector of 90 degrees given by 14, but it can be made to move at any particular sector. When the flaps retract 19 the arms fold 22 inside the wing and when they extend 21 the arms unfold 23. The axis of rotation 26 of the flap arm is parallel to vertical axis 3, hence the flap 5 moves along the plane of the wing 24. But if the axis can be rotated to make an angle with vertical axis 3, the flaps can be made to move at an angle to the plane of wing 24. Since, the flap arm moves a sector of 90 degrees angle as explained earlier. The flap arm is so place or oriented that in retracted position it is at an angle of 30 degrees with lateral axis as given by 29 and in extended position it is at angle of 60 degrees with lateral axis as given in 30. Hence the directional orientation of the sector of flap arm movement is as shown in arrow 28, where it is facing outboard 44 for leading edge flap 41 and facing inboard 43 for trailing edge flap 42. Due to the parallelogramming action of the flaps they have a sideways movement along the lateral axis. There is a peculiar directional orientation 28 of the sector in which flap arm moves. As the flap arm moves there is a lateral displacement of the flap in one direction which is very less 32 and then reverses direction to move to a larger extent on other side 33. So the resultant total lateral displacement 31 is very small.

As shown in figure 7, which shows the perspective view of the drag or turbulence caused by flap arm. The portion where the wing ends and flap starts will be termed as the threshold portion 36 of the wing. When the flap starts to extend, a part of the flap arm 6 will come in between this threshold portion of wing 36 and the flap 5. This is the actual portion 35 of the flap arm that will obstruct the airflow 37 and causes turbulence or drag 34 as shown. So we must gϊve a particular shape to the flap arm such that it causes less drag. Figure 8 shows the top view of the perspective view in figure 7. It shows a straight shaped flap arm 6 which can be used for swept back wings 13 which are swept at any angle or airy other kind of wing having some portion at an angle to lateral axis. Figure 9 shows the top view of the actual portion 35 of flap arm which causes drag when an 'L' shaped flap arm 38 is used. It can be used on rectangular shaped wings 12 or any other kind of wing having some portion parallel to lateral axis. An flap extension 39 is attached permanently to the flap and it forms and extension portion of the flap. The flap extension attaches to the extreme end of flap arm, through the sequencing mechanism, which will be explained later. The flap extension 39 will be manufactured and installed in such a way that it is always parallel to the longitudinal axis or inline with the line of flight, so that it does not cause drag. The total length 40 of flap extension including the sequencing mechanism depends on the application or which kind of flap it is used. The combination of the flap arm and flap extension will make a shape that will given the least drag from the flap arm.

The flap arm 6 moves around the center 10 and the extreme end 11 moves to two positions that is extended 21 and retracted 19. If we join the points at the extreme end 11 of flap arm in these two positions, we can get an imaginary straight line 49. Now the direction towards which the flap body moves as given by arrow 45, that side of the flap 47 (breadthwise side) will have its shape parallel to this imaginary line 49. The other side of flap 48 will have the same unchanged shape. Ηence the plan-form shape (looking from top or top view) of flap is modified from the rectangular shape. One side is at an angle 47 to length of flap 46 and other side is perpendicular 48 (unchanged) to length of flap 46. Hence due to this shape there is a no void space formation, as the flap fits properly on to the corresponding wing shape provided. To allow for the lateral movement of flaps 31, there must be a gap 50 provided between the perpendicular side of the flap and the corresponding wing shape. But on the side which is at an angle this kind of gap is not required 51. All the flap arms operate synchronously and at any given position they are all parallel to each other 25. If we consider the parallelogram formed by points 15,16,17, and 18 we have an paraUelogramming effect as the flap system moves, as it will open and close the parallelogram. The flap arms are equal in length. They move to sweep a sector of equal angles and same directional orientation

Angulating mechanism: The angulating mechanism 59 is situated at the fixed end of the flap arm around which the flap arm rotates and comprises of the support bracket (spar mount as given in the basic concept) and flap arm itself As explained in the basic in figure 1 the axis of rotation 26 of the flap arm is parallel to vertical axis 3. But if we imagine that the axis of rotation 26 can be inclined to make an angle with the vertical axis, then the flap arm can move at an angle to plane of the wing 24.

On the basis of figure 1, we will study the perspective view in figure 10. If we consider the fixed end of flap arm joint to the spar mount 10 and we imagine a fixed point 52 on the bottom part of flap arm 6 which also lies on the axis of rotation 26. Now we imagine that we rotate this axis of rotation 26 around the fixed point 52 to an angle of rotation given by 54. Now if we consider figure 14, which is top view of the view in figure 10, we see that this axis of rotation will also make an angle of 45 degrees to lateral axis as in 56 and also make an angle of 45 degrees to the longitudinal axis as in 57. Hence we get a new axis of rotation given by 53. Now the flap arm 6 and spar mount 10 will be manufactured or constructed in such a way that the fixed end of flap arm will incorporate this new axis of rotation 53 to form the angulating mechanism. So when the flap arm moves to 90 degrees angle, it also moves downwards to make an angle 55 with the plane of wing. Hence it is called as angulating mechanism 59 and this is the basic function the mechanism. In figure 14, which shows the top view, we consider the new axis of rotation 53. We see that the center point 52 which is present on vertical axis 3 is stationery on the lower side of flap arm and the upper side of flap arm portion moves as shown in the arrow 58. This justifies that the flap arm moves down rapidly to make an angle 55 to the wing and hence does not have any sequencing or preprogrammed movement.

In the above explaination the flap comes downwards with respect to wing. We can also make the flap move in upwards direction by making the axis of rotation of angulating mechanism exactly opposite as explained below. If we consider figure 12 the flap arm is joint to spar mount 10 and we imagine the fixed point 52 on the top most portion of flap arm 6 (instead of the bottom portion), which also lies on axis of rotation 26. Now we imagine to rotate this axis of rotation 26 around the fixed point 52 in exactly the opposite direction but keeping the magnitude of the angle same. The angle made by axis of rotation 26 with lateral and longitudinal axis is same as shown in 56 and 57. When the flap arm 6 moves it makes an angle upwards to the plane of wing instead of downwards as shown in 60. Hence if we compare figure 10 and figure 12, we can arrive to a conclusion that if the direction of the axis of rotation is changed we can get either upwards or downwards movement of flaps. If the angle 54 between the initial axis and the new axis of rotation is made less, then the angle 55 made by flap arms with plane of the wing is also less. So if we compare figure 10 and figure 11 or figure 12 and figure 13, we can say that the angle 55 made by flap arms with the plane of wing is directly proportional to angle 54 between initial and new axis of rotation of flap arm.

Sequencing mechanism: The sequencing mechanism is positioned at the free end or extreme end of the flap which moves around center. It consists of the tapering end 62 and swiveling joint 93. The basic function of sequencing mechanism 61 is to give proper sequencing or a pre-programmed movement to the flaps.

The tapering end, which is at the free end or extreme end of flap arm is basically responsible for the sequencing movement given to the flaps. We consider the flap arm 6 with two different types of tapering ends 62, which are of Type A given by 63 and type B given by 64. Tapering end of type A is shown in perspective figure 15 and front view is as shown by arrow in figure 18. Type B tapering end is shown in perspective view in figure 17, where figure 19 shows the front view and figure 20 shows right hand side view. The total angle made by flap with flap arm 6, due to the tapering end will be equal to the angle between the tapering end 62 and vertical axis 3 given by 66. Hence the total angle made by flaps with flap arms is directly proportional to the angle of tapering end given by 66. If we reverse or make the angle of tapering end with vertical axis is given by 66 exactly opposite, we can get the movement of flaps also in opposite direction as given in the example of angulating mechanism. The two opposite faces 69 of the tapering end side are perpendicular to the axis of rotation 65 of swiveling joint. This allows easy installation and movement of the swiveling joint when its lugs are installed on these opposite faces 69. The axis of rotation 65 of the swiveling joint is parallel and passes through the two opposite faces 69 of tapering end side 62. The angle 68 between the axis of rotation of swiveling joint 93 and plane of the flap arm 67 determines the type of sequencing movement given to the flaps. This angle 68 can be varied to give different types of sequencing movement to the flaps. The flap arm with type B tapering end 64, as seen from figure 19 and 20 have the tapering end bend at right angle. In figure 21, we give a modified shape to the flap arm by giving a twist to flap arm as shown by arrows 70, so that the angle of tapering end 66 is the same as shown in previous flap arm with type B tapering end. This modification makes this type of flap arm easy to manufacture and more efficient.

The function of the swiveling joint is to swivel around itself and allow relative movement between the tapering end side and the flap extensioa As shown in the perspective figure 26, it consists of a male part 79 and female part 80. The male part 79 is an integral part of the flap extension 39, where the end of these flap extension have external screw threads of square type 81. The female part 80 is a separate part, is ring shaped and has matching internal screw threads of square type 81. It also has two lugs 90 on diametrically opposite sides with holes for inserting fastners 88 and the length 84 of these lugs will be such as to stay clear of the flap arm in the fully retracted conditioa During installation, the male and female parts are brought together as shown by arrow 82 in the figure 26. The screw threads of both are fully engaged into each other as shown by arrow 83, to form the swiveling joint 89. Figure 27 shows how the swiveling joint is attached to the tapering end side 62 and attached by fastners 88. Figure 28 shows the sequencing mechanism as a whole and also shows imaginary cutting plane CD.

Consider the movement of the flap arm with type A tapering end; in three positions retracted 19, intermediate 20 and extended 21 as shown in figure 15. It shows the flap arm 6 only without the swiveling joint, for simplicity. The axis of rotation of swiveling joint 65 is shown which is also parallel to tapering end side. Also the vertical axis 3 is shown for all three positions. Now we suppose that the flap arm 6 rotates with the vertical axis 3 kept stationary and the flap arm is now allowed to rotate around it. Thus we superimpose all three positions of flap arm on each other to get a superimposed view as shown in figure 16 for tapering end of type A and figure 17 for tapering end of type B. We see the actual movement 71 of axis of rotation of the swiveling joint around vertical axis as flap arm moves from 0 to 90 degrees.

We consider the top views of the above superimposed views where only detailed view of the tapering end side is shown (with only the flap arm and no swiveling joint). Figure 22 shows top view of flap arm with tapering end of type A and figure 23 show top view of tapering end of type B. It shows the relation between the movement of the axis of rotation 65 and the detailed sequencing movement given to the flaps. In both the figures we can see the angle 68 made by axis of rotation of swivelling and plane of flap arm. We see the actual movement 71 of axis of rotation, which can be broken of into two components. The first component 72 is the one by which swiveling joint moves around itself and second component 73 is by which the flap moves to make an angle with flap arm. Note that in the figures the movements at the top of tapering end are followed by letter T and those at bottom by letter B. During the movement of flap arm 6 from 0 to 45 degrees, the movement axis of rotation of swiveling joint is given by 75 and the corresponding movement of second component is given by 77. In the same way during movement of flap arm from 45 to 90 degrees, the movement of axis of rotation of swiveling joint is given by 76 and the corresponding movement of second component is given by 78. From figure 22 for the tapering end of type A the angle 68 between axis of rotation and plane of flap arm is 180 degrees and which is straight to the flap arm. Considering the sequencing, we see that during 0 to 45 degrees of flap arm movement the flap movement (second component) is quite more as given in 77. For 45 to 90 degrees of flap arm movement, the flap moves quite less as in 78. So the movement of the flap is sequenced where it gets lesser and lesser as flap arm moves from 0 to 90 degrees. In figure 23 for tapering end of type B, the angle 68 between the axis of rotation and plane of flap arm is 90 degrees and hence they are at right angles to each other. Now considering the sequencing movement, during 0 to 45 degrees of flap arm movement the flap moves less as given in 77. During 45 to 90 degrees the flap arm movement the flap moves quite a large distance as given in 78. So the flap movement is sequenced such that it gets more and more, as flap arm moves from 0 to 90 degrees.

Figure 24 shows the movement of entire assembly of sequencing mechanism (with the swiveling joint also), in two positions and have tapering end of type A. It shows the flaps movement upwards 74.

Figure 25 shows the movement of entire assembly of sequencing mechanism, in two positions and having tapering end of type B. It shows the flaps movement in downward direction 74.

Flap Interconnect system: When there are two sets of flaps on the inboard and outboard side of the wing, they are mechanically connected to each other by an flap- interconnect system so that all the flaps operate synchronously with each other. To understand the function of the interconnect system of the flaps we will study the following example. This is for demonstration purpose only and actual working will be explained later.

As shown in figure 30 and figure 31, consider two bellcranks 91 with a lever 101 and an arm which rotate around the center 100 fixed to the structure, The movement in two extreme positions is shown. Now if the levers 101 of both bellcrank are connected (interconnected) by some means in such a way that if one lever moves the other also move. We see how such an interlinked assembly can be made. To do this we consider the extreme point of the lever in its initial and final position (of the lever). And we join these two points by an imaginary straight line 97. As in figure 30, if these two imaginary straight lines form a line then a straight shaped tie-rod is used as shown in 95. If these two straight lines are parallel to each other, then an offset tie-rod 96 is used as shown in figure 31. Because of this the actual movement of the tie-rods 98 as it moves with the bell cranks can be kept to the minimum. It also gives increased mechanical efficiency of the linkage. The bellcranks has to be manufactured such that when they are interconnected the levers 101 of both bellcranks must be parallel to each other as in 94 and both must be equal in length 93. The levers move to sweep a sector having the same angle and directional orientatioa They also have a paraUelograrnming effect as the levers move which, is just the same as given in the "basic concept", explaination for the flap arms of the flaps. The direction of movement of lever is shown by arrow 92.

If the assembly is supposed to be installed inside the wing of the aircraft near the spar 4 (as for the flap system). The distance between the spar and the imaginary line 97 must be kept minimum as possible, which is given by 99. Due to keeping this distance minimum, the assembly will occupy less space inside the wing and it can be placed maximum inside of the wing to allow for the placement of other components of aircraft.

This principle is used in the flap interconnect system and aft flaps actuation system.

Actuating system: It consists of an actuating flap arm on the inboard side which is moved by an actuator, to move the entire body of the flaps. To understand the system we consider the following demonstration and the actual working will be explained later;

As shown in figure 32, we consider a bellcrank 91 as in previous example which moves in three different positions which has a lever 101 and arm moving around center 100. The lever 101 is connected to the movable end 104 of the actuator 102 and the fixed end 103 is fixed to the structure. We consider the points at the extreme end of the lever in its initial and final position and the fixed end of the actuator. These three points if joined must form a straight line given by 105. Due to this there is a less movement 106 of actuator as it moves along with the bellcrank, gives better direction of application of force and increased efficiency of linkage.

If this assembly is supposed to be installed inside the wing of the aircraft near the spar 4 (as for flap system). The distance between the spar 4 and this imaginary straight line 105 must be kept minimum as possible, as given by arrow 107. Due to this the assembly occupies less space inside the wing and can be placed maximum inside the wing to allow for placement of other components.

This principle is used for the actuating flap arm of the flaps. Brief Describtion of the drawings: The following is the list of the various figures shown in the drawing and a brief explaination to what it pertains;

FIG 1- Shows isometric or perspective view of a rectangular shaped wing with only one flap on trailing edge, for explainaiton of the basic concept of the new inventioa The flap is shown in three positions which are retracted, intermediate and extended. An arrow shows the top of the drawing (Top view direction)

FIG 2- Shows the plan or the top view of the view shown in FIG 1. It shows the formation of the imaginary parallelogram and shows how the flap arms are parallel to each other at all times. Also shows the formation of void space given by hatching in horizontal lines.

FIG 3- Shows the perspective view of an swept back wing where we study the application of the basic concept as shown in FIG 1. Here both the leading edge and trailing edge flaps are present, given in two extreme positions. Arrows point to the direction of top view and side view. Please note the direction of the side view, which is parallel to both the spars and is done for simplicity of observatioa

FIG 4- Shows the top view of the view shown in FIG 3 and shows the direction of movement of the flap components.

FIG 5- Shows the side view of the view shown in FIG 3

FIG 6- Shows the top view of an rectangular or straight shaped wing, where the basic concept as shown in FIG 1 is applied. Here the perspective view and side view are not shown, as the construction is generally the same as for swept back wing in FIG 3. The only diffrence being the use of 'L' shaped flap arm

FIG 7- Shows as perspective view of the actual portion of the straight shaped flap arm and sequencing mechanism which comes in between the airflow and causes turbulence or drag. Only a certain portion of the flap is shown here, which is done for explaination purposes only. An arrows shows the top of figure.

FIG 8- Shows the top view of the perspective view in FIG 7. Shows the actual portion of straight shaped flap arm which causes drag, in three different positions. Shows the top view of the actual portion of flap arm which causes drag when an 'L' shaped flap arm is used. Here the perspective view is not shown for this view as it will be same as FIG 7. Shows the perspective view of the formation of angulating mechanism. It shows how the initial axis of rotation of flap arm is inclined at an angle to form a new axis of rotation of the flap arm and how the flap moves downwards. Shows the perspective view same as that in Figure 10, but has a less angle of inclination to initial axis of rotation. So the angle made by the flap with plane of wing is also less. Shows the perspective view of the angulating mechanism in which the initial axis of rotation is inclined to an angle to form a new axis of rotation as given in Figure 10.

Here the angle of inclination is same in magnitude, but direction is exactly opposite.

So we get movement of flap upwards. Shows the perspective based upon the flap shown in Figure 12, but having a less angle of inclinatioa So angle made by flap with the plane of wing is also less.

(Note: The flaps as shown in Figure 10,11,12,13 and 14depict just a small portion of the flap of the entire flap body. The aerofoil shape of the flap shown in the drawing is not the exact shape of the actual flap. There are done for demonstation purposes only and simplicity of understanding.) Shows the top view of perspective view in Figure 10. It shows how the new axis of rotation is inclined to the vertical, lateral and longitudinal axis (The vertical axis is shown by a dot inside the circle, it is perpendicular and coming out of the paper). Shows the perspective view of the movement of flap arm showing the tapering end of

Type A only, in three positions. It shows relation between the tapering and side and vertical axis. Shows a superimposed view of the perspective view shown in Figure 15, where flap arm with tapering end of Type A shown in the same three positions and supposed to be rotating around the vertical axis. It shows the movement of the tapering end with relation to vertical axis. Shows a superimposed view of flap arm with tapering end of Type B, in two positions. Here the perspective view is not shown as it will be similar to that in

Figure 15. The flap arm is supposed rotate around the fixed vertical axis. Shows the front view of flap arm with Type A tapering end and shows its acutal construction (shown by arrow F in Figure 16). Shows the front view of flap arm with Type B tapering end and shows its acutal construction ( shown by arrow F in Figure 17). Shows the right hand side view of flap arm of Type B tapering end, shows a more detailed view to that in Figure 19 (shown by arrow 9 in figure 17) Shows the perspective view of the modified shape of the flap arm with Type B tapering end. Shows the top view, of only the portion of tapering end of Type A as given in superimposed view of Figure 16, in three postions. It gives the relation between the movement of axis of rotation of swivelling joint and sequencing movement of the flaps. Shows the top view of the portion of tapering end only of Type B, as given in superimposed view in Figure 17 in three positions (and not in two positions as in

Figure 17). It gives the relation between the axis of rotation of swivelling joint and sequencing movement flaps. Shows the perspective view of the entire assembly of the sequencing mechanism in two positions. This is formed by the flap arm with Type A tapering end, swivelling joint and flap extension with the flaps. Shows the flaps moving in upwards direction. Shows the perspective view of the entire assembly of sequencing mechanism in two positioa This shows the movement in downwards direction of flap arm with Type B tapering end, swivelling joint and flap extension with the flaps. Shows in the perspective view how the male part and female part are brought together and screw threads between them are fully engaged to form the swivelling joint Shows in the perspective view, how swivelling joint is attached to tapering end of flap arm by fastners. Shows the entire mechanism of sequencing mechanism. The imaginary cutting plane is vertical as shown by sectional lines C and D. Shows sectional view of CD, it shown the internally drilled passages and gaps formed between the screw threads which are for lubrication of the swivelling joint. Shows a simple top view of the two bellcranks with movement in two postions, have a straight interconnect tie rod as both bellcranks are inline. Shows a simple top view of the two bellcranks with movement in two positions, having a offset interconnect tie-rod as both bellcrank are not placed in one line. Shows a simple top view of actuating flap arm which is just like an bellcrank. It shows the actuator and its movement in three positions. Shows a top view of aft flap mechanism It shows in details all the components associated with aft flap and how it is connected to the main flap. Shows the top view of the flap, where the aft flap tie-rod and associated component are placed on the inboard side of flap. Shows the top view of the flap, where the aft flap tie-rod and component are placed on the outboard side of flap. Shows perspective view of the two ducts and their respective open bulbed shape. Shows perspective view of the two ducts forming a joint by forcing together the two open bulbed shapes into each other. Shows the sectional top view of IJ, shows the amount of movement of the duct from its initial position. Show the top view of the figure shown in figure 43. It depicts the actual arrangements of the anti-ice system of flaps in two extreme positions. Shows the top view of drawing in figure 43, particularly showing the coupling joint which joins all ducts in the slats end to end. Shows sectional side view of EF as shown in Figure 43, showing the slats in retracted position and depicts the placement of the anti-ice ducts. Shows sectional side view of GH as in figure 43, shows the slats in extended position and depicts placement of ducts and path taken by anti-ice hot air. Shown the perspective view of the construction of the leading edge slats on an twin engine aircraft. This shown the actual industrial applicability as given in Example 1. Shows the top view of the actuating flap arm with the actuating lever, which is the best mode of constructing the actuating flap arm for the leading edge slats. Shows the side view of the actuating flap arm with actuating lever, which is the best mode of constructing the actuating flap arm for the leading edge slats. Shows the front view of the actuating flap arm with actuating lever, which is the best mode of constructing actuating flap arm for the leading edge slats. FIG 47- Shows the perspective view of the actual construction of the interconnect hinge and bolt assembly which joins the leading edge slats end to end. Also note the coupling joint which joins the ends of the anti-ice heating duct. FIG 48- The perspective view of the interconnect and actuating flap arm of the trailing edge flaps in its best mode of constructioa FIG 49- The top view of that shown in perspective view in figure 48, of the interconnect and actuating flap arm. FIG 50- The perspective view of the interconnect flap arm with the interconnect lever, used for the trailing edge flaps. This is the best mode of constructing the interconnect flap arm. FIG 51- Shows the perspective view of the construction of the flap skew sensor and its actual placement on the support bracket. Sectional cutting plane KL showa FIG 52- Shown the sectional view of KL as shown in figure 51. It shown the internal construction of the flap skew sensor. FIG 53- Shows the perspective view of the fastner and shows the sectional cutting plane MN FIG 54- Shows the sectional view of MN as shown in figure 53, and it shows the cross sectional shape of the fastner. FIG 55- Shows the top view of the perspective view in figure 43 of leading edge slats. This view is an interrupted view as shown by the break lines. FIG 56- Shows the perspective view of the construction of the leading edge slats as on an four engine aircraft. This shows the actual industrial applicability as shown in Example 2. FIG 57- Shows the top view of the view in figure 56 of leading edge slats. FIG 58- Shows the perspective view of the construction of the trailing edge flaps on twin engine aircraft. This shown the actual industrial applicability as shown in Example 1. FIG 59- Shows the top view of the view in figure 58 of trailing edge flaps. FIG 60- Shows the perspective view of the construction of the trailing edge flaps on an four engine aircraft. This shows the actual industrial applicability as shown in Example 2. FIG 61- Shows the top view of the view shown in figure 60 of trailing edge flaps.

Best Mode of carrying out the Invention: We will design a new system for actuation and movement of the Leading edge slats and Trailing edge flaps, on a large passenger transport catgggry aircraft . We study and analyse the basic ideas given in the various topics of "Disclosure of the Invention", and try to use these ideas to design a flap arm for the Leading edge slats and Trailing edge flaps respectively.

Flap arm design for Leading edge slats: For the leading edge of the aircraft only the slats on the outboard side are discussed here, but the Krueger flaps on the inboard side are not discussed as they do not form a part of the inventioa We study the various modes or ideas of the invention given in the topic of "Disclosure of the Invention", as given below in 1,2,3,4,5 below and analyse them to select the Best Mode or best basic ideas for the leading edge flap arm, actuating lever and interconnect levers. The following lists the best mode selected for leading edge slats;

1. We study the explaination of "Application of the basic concept" and analyse the concept of the swept back with 13 given in figure 3,4,5 and note the leading edge flaps 41. Now the leading edge slats in the best mode of invention (as shown in figure 56 and 57) will be based on the same concept as the wing has a angle or a swept back. A .i) The flaparm moves a sector of 90° as in 14. ii) They fold 22 to retract and unfold 23 to extend the flaps. B .i) The flap arm will be so placed that in retracted position it is at an angle of 30 degree with lateral axis as given by 29 and in extended position it is at an angle of 60 degrees with lateral axis as given by 30. ii) Hence the directional orientation of the sector as given by arrow 28 will be towards outboard 44 for leading edge slats 41.

C. The total lateral displacement is quite less as given by arrow 31

D. i) The flap arm 6 will be straight in shape. Since the flap arm are placed inside for leading edge slats they do not obstruct the air flow and hence do not cause any drag, ii) The flap extensions 39 are permanently attched to the slats and are placed parallel to longitudinal axis.

E. i) The slat moves towards inboard 43 as shown by arrow 45. So that side of slat

(inboard) will have shape 47 parallel to the imaginary line 49 and the other side 48 will have the side perpendicular to the length of slat, ii) To allow for lateral movement there is a gap 50 provided between the flap and wing body.

F. All flap arms of leading edge slats are parallel to each other at all times as shown by 25, they are of equal lengths and sweep sectors having equal angles. Hence they have a parallelogramming effect as flaps move. 2. We study the explaination "Angulating mechanism." and select the suitable angulating mechanism for leading edge slats is the one given in figure 10 and 14.

A. Note that the axis of rotation 53 for flap arm is inclined to make an angle with vertical 3, lateral 1 and longitudinal 2 axis.

B. The leading edge flap arm will move steeply downwards to make an angle given by arrow 55 with plane of the wing.

3. We study the topic "Sequencing mechanism", and study the most suitable for the leading edge slats as given below;

A. i) It consists of tapering end 62 and swivelling joint 93. ii) For leading edge flap arm, tapering end of Type A as given by 63 is used which are shown in figure 15 and 18. iii) The total angle made by flap with flap arm, due to tapering end will be equal to the angle between tapering end and vertical axis given by 66. iv) The two opposite faces 69 of tapering end side are perpendicular to axis of rotation, for easy movement of swivelling joint.

B. The swivelling joint consists of a male and female part as shown in figure 26,27, and 28.

C. i) Consider the superimposed view of flap arm in figure 16 and its top view in figure

22. ii) The actual movement 71 of the axis of rotation of swivelling joint can be seen, which can be broken off into two components. The first component 72 is one by which swivelling joint moves around itself and second component 73 is the one by which flap moves to make an angle with flap arm. iii) The movement of the second component 73, is large when flap arm moves from 0 to

45 degrees and it goes on decreasing as it moves from 45 to 90 degrees.

D.i) Figure 24 shows the movement of entire assembly of the sequencing mechanism and shown how it moves in upwards direction in an highly programmed manner, ii) The angulating mechanism moves downwards rapidly and the sequencing mechanism moves upwards in an sequenced manner. Hence the counter reactions of both assemblies are balanced to give a proper programmed movement of the slats.

4.A. We study 'Tlap interconnect system" and select the most suitable system for leading edge slats. The function of interconnect system is to mechanically interconnect all the slats, so that they all operate synchoronously. B. When the slats are arranged one after the other to make one full set. They are joint to each other end to end by flap interconnect hinge and bolt assembly 218 as shown in figure 55 and 43.

C. i) The slats may also be arranged in two separate sets where one will be on inboard and other on outboard side. Now just as the example shown in figure 30, the flap arms on two slats will have interconnect levers as an integral part of flap arm. Since the slats are arranged in a linear manner, the two levers will be correctly by a straight shaped interconnect tie rod 210 as shown in figure 57 and 56. ii) The levers 209 are so manufactured and oriented at such angle so that they have the same pai elogramming effect (see 94) as given for flap arms in paragraph 1.F.

5. A. We study the topic "Actuation system" and select the most suitable system for leading edge slats.

B. The most inboard flap arm will act as actuating flap arm and will move the entire slats on a wing. As shown in figure 32, the flap arm has a lever called as actuating lever and this is same type as explained for interconnect lever.

C. Here an hydraulic actuator is used to power the lever to actuate the slats, because the slats only move in discrete positions and there is no fine change of movement.

We study and analyse all the points various basic ideas given in topics 1,2,3,4 and 5 above and incorporate or combine there basic ideas to create the best possible flap arm (flap arm only) for leading edge slats as follows; (also see figure 57 and 56)

The actuating^flap arm is as shown by top view in figure 44, side view in figure 45 and front view in figure 46. It has an actuating lever 208 which attaches to the movable end of the hydraulic actuator 211 and moves with it. A bracket 213 holds the fixed end of the actuator. The actuator has a ball type eye end 212 on both the ends. The angulating 214 and sequencing mechanism 215 are shown. The movement of the actuating lever is shown by 217 .

The interconnect flap arm is the same as actuating flap arm in every respect.

Flap arm for Trailing edge flaps: We study the various modes or ideas of the invention given in the topic "Disclosure of the Invention" as given in 6,7,8,9,10 and analyse them to select the Best Mode or the best basic ideas for the Trailing edge flap arm, actuating and interconnect levers. The following lists the best mode for the trailing edge flaps; 6. We study the explaination under "Application of the basic concept" A. i) We analyse the trailing edge flaps 42 the concept given for swept back wing 13 as shown in figure 3,4,5. Since this concept can be used on any wing with an angle or sweep back, we use this type of flaps for the trailing edge outboard flaps 302 on the best mode of the invention as in figure 60 and 61. ii) We see the trailing edge flaps 42 in the concept given for straight wing 12 as shown in figure 6. Since this concept can be used on any kind of wing where some of its portion is straight or parallel to lateral axis of aircraft, hence we use this type of flap on the trailing edge inboard flaps 301 on the best mode of invention as in figure 60 and 61. iii) So there are two trailing edge flaps which are inboard and outboard flaps, and there are two flap arms each on every flap with a total of four flap arms on each wing. B.i) All four flap arms move a sector of 90° as shown by arrow 14. ii) All four flap arms fold 22 to retract and unfold 23 to extend the flaps. C.i) All four flap arms will be so placed that in retracted position it is at an angle of 30 degrees with lateral axis as given by 29 and in extended position is at an angle of 60 degrees with lateral axis as given by 30 ii) The directional orientation of the sectors swept by all four flap arms is as given by arrow 28 will be towards inboard 43 for trailing edge flaps 42. D. The total lateral displacement is quite less as given by arrow 31. E.i) The flap arms will be straight shaped 6 for outboard flap 302 and 'L' shaped flap arm 38 for inboard flap 301, as shown for the best mode of invention in figure 60 and 61. ii) Figure 7,8 and 9 shows the turbulence or drag created by both types of flap arms. It shows the actual portion 35 of the flap arm which obstructs the airflow to cause turbulence or drag 34. iii) The flap extensions 39 are designed such that they are parallel to longitudinal axis, but their length 40 can vary depending on the applicatioa F.i) Both the trailing edge flaps move outboard 44 as shown by arrow 45. So the outboard side of flap will have a shape 47 parallel to the imaginary line 49 and other side 48 will have the side perpendicular to length of flap, ii) To allow for lateral movement there is a gap 50 provided between the flap and wing body. G. All the four flap arms of trailing edge flaps move parallel to each other at all times, they are equal in lengths and sweep sectors having equal angle and same orientatioa Hence they have same parallelogramming effect as given for leading edge slats in paragraph l.F

7. The angulating mechanisam is not used for the best mode of invention in figure 48 and 49. However it can be used for trailing edge flap arm if required. The suitable angulating mechanism can be that given in figure 13, which moves upwards and makes a small angle with plane of the wing given by 60.

8. We study the topic "Sequencing mechanism" and study the most suitable for trailing edge flaps as given below.

A i) It consists of tapering end 62 and swivelling joint 93 ii) For trailing edge flap arm, tapering end of type B as given by 64 is used which is shown in figure 17,19 and 20. iii) The total angle made by flap with flap arm, due to tapering end will be equal to the angle between tapering end and vertical axis as given by 66. iv) The two opposite faces 69 of tapering end side are perpendicular to axis of rotation, for easy movement swivelling joint 93. v) Figure 21 shows the modified shape of the tapering end which is incorporated in trailing edge flap arm B. The swivelling joint 93 consists of a male and female parts as shown in figure 26,27 and 28.

C. i) Consider the superimposed view of flap arm of type B in figure 17 and top view in figure 23. ii) The actual movement 71 of the axis of rotation of swivelling joint can be seen, which can be broken off into two components. The first component 72 is the one by which the swivelling joint moves around itself and second component 73 is the one by which the flap moves to make an angle with flap arm. iii) The movement of second component 73, is very small when flap arm moves from 0 to 45 degrees and it goes on increasing rapidly when flap arm moves from 45 to 90 degrees. iv) The angle 68 between the axis of rotation and plane of flap arm is 90 degree, which is responsible for the type of sequencing given to the flaps.

D. i) Figure 25 shows movement of the entire assembly of sequencing mechanism and shows how it moves in downwards direction 74 in a sequenced manner. ii) The angulating mechanism is not used here, so the flap arm moves along the plane of the wing. When flap arm moves from 0 to 45 degrees in take off position, the flap has a very small change in the angle. When flap arm moves from 45 to 90 degrees in landing position, the flap moves rapidly downward to make an angle with the wing. 9.A. We study the 'Tlap interconnect system" and select the most suitable system for trailing edge flaps. B.i) The trailing edge flaps are of two types, inboard and outboard. So the most nearby flap arms of these flaps have an interconnect lever 310 as an integral part of the flap arm since the flaps are arranged in a non-linear manner (not in a straight line), so they will be connected by an offset tie rod 96 as given in the example in figure 31. ii) When the offset tie rod 96 moves it sweeps a large area and hence needs a lot of space for movement. So we use a 'Z' shaped tie- rod 323 in the best mode as given in figure 60 and 61, as this tie rod needs quite a less space, iii) The levers are so rnanufactured such that they have a paraftelogramming effect just like that given for flap arms and explained in paragraph l.F. 10. We study the "Actuation system" and select the most suitable for trailing edge flaps.

A. The outboard flap arm of the inboard flap 301 will act as an actuating flap arm and hence will have a lever called as actuating lever as shown in figure 32.

B. The interconnect and actuating levers are combined together on the flap arm to form interconnect and actuating flap arm 307 as given in best mode in figure 48 and 49.

C. A screw jack 311 is used to power the actuating lever of interconnect and actuating flap arm because the trailing edge flap require very fine changes in movement. The torque tube used to move the screw jack is reduced in length.

We study and analyse all the points and various basic ideas given in the topics 6,7,8,9 and 10 and incorporate or combine all these basic ideas to create the best possible flap arm (flap arm only) for the trailing edge flaps as follows: (also see figure 60 and 61)

The interconnect and actuating flap arm is shown in figure 48 and its top view shown in figure 49. The flap arm is 'L' shaped 38 and it has an actuating lever part 308 and also a lug

309 which acts as an interconnect lever. The actuating part of this flap arm is connected to a ball nut 313 of the screw jack 311. The ball nut sides on the ball screw 312 which rotates through the torque tube 316 via the bearing 315 and universal coupling 314.

The interconnect flap arm has a straight shaped flap arm and has an interconnect lever

310 to which the 'Z' shaped tie-rod 323 is connected. This is as shown in figure 50. Industrial Applicability : Here we study the actual adaptation of this flaps system on an passenger transport aircraft and the aft flaps and anti ice system used.

Aft Flap Mechanism For Trailing Edge Flaps: The aft flap is placed after the fore flaps (main flap) to form the double slotted flaps on trailing edge of aircraft. They are quite smaller in size than fore flap and the operational principle is same as that of fore flaps. On each individual wing the aft flap is in two parts which are inboard and outboard with a distance separating them both. This is done to keep clear of the turbine engine exhaust path when the flaps are extended.

The aft flap operates on the same principles and has the same components as the main flap. As shown in figure 33 shows in details all components associated with the aft flap 401. The aft flap has an aft flap's flap arm 402 which for inboard is same as inboard main flap arm and the outboard aft flap arm 403 is same as outboard main flap ar It also has the aft flaps sequencing mechanism 404, flap extension 405 and aft flap arm support bracket 406 ;same as that of the main flap. But the only difference being that they are much smaller in sizes as compared to main flap, because as we know that the aft flap is smaller than main flap. The flap arms of aft flap also have the same parallelogramming effect during its movement, which is just like the main flaps. The aft flap's flap arm on the most extreme end will act as an actuating flap arm for aft flap, where it is mechanically connected to or receives input from the main flap. The other flap arms of aft flap act as follower flap arms. The actual construction as given in figure 33, shows an lug 410 on the flap arm 407 of aft flap; actuating flap arm and an lever 409 on the end of main flap's flap arm 38. This lug and lever are mechanically connected to each other by a actuating tie-rod 408 of aft flap. Due to this as the main flap arm moves, it also moves the aft flaps flap arm. The arrow 411 shows the movement of the lever 409 on the main flap arm through the initial and final positioa Also the arrow 412 shows the movement of the lug 410 on the flap arm of aft flap through initial and final position. If we join the points on extreme positions of the lever and on the lug, we get an imaginary straight line given by 413. Hence it is the same principle as used for flap interconnect mechanism as given in figure 30.

As the aft flap actuating tie-rod 408 and other component are placed on any of the sides of the flap (breadth-wise). For any given flap we can have the aft flap components on the inboard side 43 or outboard side 44 of the flap, depending on type of wing and construction of flaps. Figure 34 shows the flap with the aft flap tie-rod and other components on the inboard side 43 of flap. Figure 35 shows a flap with aft flap tie-rod on the outboard side 44 of flap. In this system for aft flap, the aft flap tie-rocfl|nd other associated mechanism pass from the sides (or outside) of the flap body as explained abββg. Hence as nothing passes from inside the flap body, it can be made solid without any holes of open cavities for passing any tie-rods.

Anti ice system for leading edge slats: To understand the anti-ice system we first study the joints made on the ducts in the following example;

In figure 36 we can see the two ducts which have to be joint to each other by a flexible (movable) joint. The ducts 501 are circular in cross-section and hollow. The ducts have a bulbed shape as in 502, 503. These bulbs can be considered to be part of the sphere, from where they are out. One bulb 502 has a diameter slightly larger than the other bulb 503 such that both can just fit into each other. The open bulb with a smaller diameter 503 has a groove for seals (o-rings) 504 on the outside and other bulb with larger diameter 502 has the seals 504 on the inside. In figure 37, we see that as these ducts cannot be pressed inside each other. Hence we have to force them by some form of a pressing tool as shown in arrow 505. Figure 38 shows the sectional view of I J in figure 37. Hence we have a joint which moves at an angle of 45 degrees from the initial position 506 as is given by the arrow 507 and can move anywhere in three dimensional space at an angle of 45 degrees from initial positioa So the total angle of movement of the duct from one end to the other is 90 degrees as given by 508. If we consider the center line 509 of the imaginary sphere from which the open bulbed shape of the duct is supposed to be formed, we can see that the bulb shapes are not cut exactly at the center line. The open bulbed shape is cut (or made open) after some distance 510 of the centerline, so that the bulbed shapes cannot come out of each other and also have a relative movement between each other.

The connecting duct 522 is placed at the most inboard position of the slats, it is a short lengthed movable duct and its functions is to receive hot anti-ice air from supply duct 518 and carry it to the heating duct 517 inside the slat . The direction of flow of air inside the duct is shown by arrow 521. Consider figure 39 which shows the top view of the whole assembly in two positions. The connecting duct 522 is joint on both end by open bulbed joint as discussed earlier. The end of the duct which is fixed is joint to the supply duct 518 and other end which is movable is joint to the heating duct 517 inside slat. Here the diameter of the open bulbed ends 502 of the connecting duct is larger than the bulbed ends of supply or heating ducts. The portion of the duct 522 near the fixed movable end is given a peculiar bend given by 514, so that the axis of rotation of the duct at fixed end can be inclined. This axis of rotation is exactly paralled to axis of rotation 53 of angulating r echanisra A bolt and nut 515 are installed in the joint at a position which is parallel to axis of rotation 53 of angulating mechanism, so that it moves in the same wayj* angulating mechanism. Hence the connecting duct will also move in a syncronised manner with the flap arms and slats. The actual construction and operation of the connecting duct is similar to operation of the flap arms of leading edge. The length of the duct is similar to that of the flap arm as given in 511. The angle 513 made by the duct in fully retracted position and lateral axis is 30 degrees, hence the duct has the same directional orientation as the flap arm The total angle of movement of the duct is 90 degrees which is same as flap arm, as given by arrow 512. Just as the flap extensions are parallel to longitudinal axis, the portion of the heating duct which is exposed to airflow as given by 516 is also parallel to longitudinal axis. The axis of rotation of the duct will be same as that of the angulating mechanism given by 53, due to which it operates in the same way as the flap arm.

Figure 40 shows the top view, showing the coupling joint which connects all the heating ducts inside the slat. The coupling joint 519 is a small lengthed, cylindrical shaped which is put on the ducts end to end. The coupling joint is fitted with heat resisting seals and fitted end to end on the duct so that the anti-ice air given from connecting duct is passed through entire length of the duct. The coupling joint can be very easily slided off the duct as shown by the arrow 520, for easy installation and removal.

We consider the sectional side view of leading edge slats in two positions. Consider figure 41, the sectional view of EF which shows the slats in retracted position and figure 42 shows the sectional view of GH, which shows slats in extended positioa These views show the actual arrangement of the various anti-ice ducts and related systems as explained earlier. These figures show the movement of the anti-ice air inside the slat body, which does not form the part of this invention as this is used in all kinds of aircrafts.

Fastner : A special type of fastner 88 are used to join two moving parts of assembly of the flaps actuation systems. The support bracket 27 is joint to flap are 6 and the tapering end 62 of flap arm is joint to the lugs of the swivelling joint 89 by two fastners on each of these joints. But they can be used anywhere, where a movable joint is to be farmed. Figure 53 shows the prospective view of the fastner and figure 54 shows sectional view of MN. The fastner has a thicker shank portion 108 having more diameter and bearing surface area, so that it can be used to join thicker parts like that of the flap ana The threaded portion 109 has less diameter than the shank portioa The head 110 is relatively thinner in shape, but has a more surface area. It has a hexagonal slot 111 in the center provided for tightening with an alien key. It also has internally drilled passages 86 for passage of lubricant.

Flap skew sensor : Figure 51 shows the perspective view of flap skew sensor (or flap position transmitter) and figure 52 shows the sectional view KL, which shows the detailed construction of the sensor. The flap skew sensor 112 is of an conventional type and its construction is just like any other position sensor, consisting of stator and rotor which are concentric each other. The skew sensor stator part 113 is placed on the extreme tip of the support bracket 116, on a point which is an the axis of rotation of the angulating mechanism 53 and hence forms the stationary part.

The rotor 114 moves inside the stator and has an hexagonal shaped stud 115 which fits on the matching hexagonal slot 111 on the fastner. As the flap arm moves, the fastner moves and hence the rotor will move exactly as the flap ana So when the rotor moves is respect of the stator, the sensor will generate an electrical signal proportional to the movement. All the flap skew sensors on the flap arms act as syncro sensors and sense if all the flap skew sensors are operating in the same phase.

Lubricating system: Figure 29 shows the sectional view of CD of the sequencing mechanism in figure 28, which shows the lubricating system comprising of the internal drilled passages 86 and gaps 85 formed between screw threads. For the swivelling joint, 89 the screw threads of the male part 79 are cut more deeper than the female part 80, so that when these tow parts are engaged a gap is formed between the screw threads. When attempted to lubricate through the lubricating point 87 the lubricant passes through the internally drilled passages 86 which open up to the gaps 85, where the lubricant passes through the gaps to lubricant the entire screw threads at one time.

When the tapering end 62 is lubricated through its lubricating point 87, the lubricant passes through the internal drilled passages of tapering end. The lubricant reaches both the fastners and lubricants their bearing surface in justone attempt only.

Here we study the actual practical application of the leading edge and trailing edge flaps system for a passenger transport category heavy aircraft. Example 1 shows the flaps system system installation on an twin engine aircraft and Example 2 shows the installation on a four engine aircraft. Example 1 : In case of an twin engine aircraft we have; a) Leading edge slats: Figure 43 shows the perspective view and figure 55 shows its top view of this type of leading edge slats. The front spar 216 has four flap support brackets 27 on which four flap arms of different types are attached. The first flap arm from inboard given by 202 is the actuating flap arm which has an actuating lever 208 as shown in figure 44,45,46. The second 203, third 204 and fourth flap arm 205 from the inboard, are of the same type as the actuating flap arm but the only diffrence is that there is no actuating lever. These flap arms just move with the slats and hence they are called follower flap arms.

There are three slats 201 which are placed end to end. All these slats are interconnected end to end by an interconnect hinge and bolt assembly 218 so that they make one full set, as shown in figure 47.

The actuating lever 208 of the actuating flap arm is moved by the hydraulic actuator 211, to move all these slats at one time.

The anti-ice system has heating ducts 517 inside the slats which are joint by a coupling joint 519. One connecting duct 522 is placed on the most inboard side. Four flap skew sensors 112 are placed on the tip of the support bracket. b) Trailing edge flaps: The flaps system of this type is shown is the perspective view in figure 58 and the top view is shown in figure 59. The rear spar 320 has two support brackets 27 on which two straight flap arm 6 are placed. Here the outboard flap 302 is placed parallel to the rear spar. The landing gear beam 321 has two support brackets 27 on which two 'L' shaped flap arm 38 are placed. The inboard flap 301 is placed on this, parallel to landing gear bea

The first flap arm inboard 303 has an lever 409 for actuating the aft flap 401 as shown in figure 33. The second flap arm from inboard 304 is the actuating and interconnect flap arm 307 as shown in figure 48 and 49. The third from inboard 305 is the interconnect flap arm as shown in figure 50. The fourth from inboard 306 has a lug for the aft flap actuation system and is as shown in figure 35.

The 'Z' shaped interconnect lie-rod 323 will connect to the lug 309 which functions as interconnect lever on interconnect and actuating lever. The other end of tie-rod connects to lever of interconnect flap arm.

The torque tube runs only half the distance in the wing and rotates the screw jack, which moves the actuating lever part 308 of the interconnect and actuating flap arm 307. There are four flap skew sensors 112 placed on the support brackets. Example 2: In case of four engine aircraft; a) Leading edge slats: The flaps system is shown in the perspective ^m in figure 56 and the top view of the same is shown in figure 57. The front spar 216 has four support brackets 27 on which four flap arms of different types are attached. "Λ* first flap arm from inboard 202 is the actuating flap arm as shown in figure 44,45, and 46. The second 203 and third 204 are both the same and are the interconnect flap arms and has the interconnect lever 209 which is same as the actuating lever. The fourth 205 from inboard is just a follower flap arm.

There are two separate slats, which are inboard slats 206 and outboard slat 207. The interconnect tie-rod 210 connects the interconnect levers 209 of the interconnect flap arms.

The hydraulic actuator 211 moves the actuating lever 208 of actuating flap arm which moves the inboard slat 206. This moves the interconnect levers which are connected by interconnect tie-rod to move the out board slat 207.

Two connecting ducts 522 are placed on the inboard side of each of the slats, which supply anti-ice hot air to the heating duct 517 inside the slats.

Four skew sensors are placed on each of the support brackets.

b) Trailing edge flaps: The flaps system of this type is shown in the perspective view in figure 60 and the top view of the same is shown in figure 61. The placement of the inboard flap 301 and outboard flap 302 and also the type of flap arms used will the same for this type of flaps as explained earlier in Example 1.b) for Trailing edge flaps. The only difference being that both these flaps are seperated from each other and the high speed aileron 325 is placed between them. The low speed aileron 324 is placed outboard of the outboard flaps.

The first flap arm 303 from inboard has a lever 409 for the aft flaps actuation system as shown in figure 33. The second from inboard 304 is the actuating and interconnect flap arm 307 as shown in figure 48 and 49.

The third 305 from inboard has interconnect lever 310 as shown in figure 50 and also has a lever for actuating the aft flap as shown in figure 34.The fourth 306 from inboard is just a normal flap arm.

The explanation for the flap interconnect system (with the 'Z' shaped tie-rod) and actuation system (for screw jack and torque tube) will be the same as given in Example 1.b) for the trailing edge flaps. There are four skew sensors 112 placed on support brackets. The list of the reference signs used in the drawings are as given below, it gives the number of the reference sign and a brief explaination to what it pertains;

1. Anow showing lateral axis of aircraft

2. Arrow showing longitudinal axis of aircraft

3. Anow showing vertical axis of aircraft

4. Wing spar (general)

5. Wing flaps (general)

6. Flap arm, of straight shape

7. Void space, which is left by the flap due to its movement.

8. Arrow showing direction of top view of drawing

9. Arrow showing direction of side view of drawing.

10. Spar mount or the center point of imaginary circle around which flap arm rotates.

11. Flap mount or the extreme end point of the flap arm which connects to the flap.

12. Straight or rectangular shaped wing

13. Swept back wing

14. Sector of 90° angle, swept by the flap ana

15,16,17,18. Shows the points by which the imaginary parallelogram is supposed to be formed.

19. Full retracted position of flap arms and flaps.

20. Intermediate position of flap arms and flaps.

21. Full extended, position of flap arm and flaps.

22. Folding action of flap arm during flap retractioa

23. Unfolding action of flap arm during flap extensioa

24. The plane of the wing

25. shows that the flap arms are parallel to each other at all times.

26. the axis of rotation of flap ana

27. Support bracket of flap arm

28. The directional orientation of the sector swept by flap ana

29. The angle between flap arm in retracted position and lateral axis.

30. The angle between flap arm in extended position and lateral axis.

31. Total lateral displacement of the flaps. 32. Small lateral displacement of flaps.

33. The large lateral displacement of flaps.

34. Turbulence or drag in airflow.

35. Actual portion of the flap arm which obstructs the airflow to cause turbulence.

36. The end portion of wing or threshold portion between the wing and flap.

37. Airflow direction.

38. 'L' shaped flap arm, used on rectangular shaped wings.

39. Flap extensions which are permanently attached to flaps.

40. Total length of extension is the length of extension and sequencing mechanism

41. Flaps on leading edge of wing.

42. Flaps on trailing edge of wing

43. inboard of the aircraft wing

44. Outboard of the aircraft wing.

45. Direction of movement of the flap body.

46. Anow showing the length of the flap.

47. The side of the flap, which is modified to make it parallel to the imaginary straight line and it is also at an angle to length of the flap.

48. The side which is perpendicular to length of the flap.

49. The line joining the two extreme end points of the flap ana

50. The gap formed between the flap and corresponding wing shape, to allow for lateral movement of flaps.

51. The angular side, which has a corresponding matching shape on the wing, without any gaps.

52. The fixed point on the initial axis of rotation around which it is supposed to incline to form the new axis of rotation for angulating mechanism.

53. The new axis of rotation, which forms angulating mechanism

54. The angle between the initial axis of rotation and new axis of rotation, which can be made large or small to get desired angulation of the flap ana

55. The angle made by the flap arm with plane of the wing in downwards direction, which can be large or small depending on angle shown in 54.

56. The angle of 45° made by the new-axis of rotation with lateral axis.

57. The angle of 45° made by the new axis of rotation with longitudinal axis. 58. The arrow showing the movement of the particular portion of the upper side of flap arm with the center at the lower side of flap arm stationary. This justifies the rapid change of the angle of flap with plane of wing.

59. Angulaling mechanism

60. The angle made by the flap arm with the plane of wing in upwards directioa This can be made small or large depending on angle made by axis of rotation to the initial axis.

61. Sequencing mechanism.

62. The tapering end side on the movable end of flap ana

63. Tapering end of Type A

64. Tapering end of Type B

65. Axis of rotation of swivelling joint which is also parallel to tapering end side.

66. Angle made by this axis of rotation with vertical axis,

67. Line depicting the plane of flap arm.

68. Angle between plane of flap arm and axis of rotation of swivelling joint, which can be varied as required to get the type of sequencing required.

69. The opposite faces of the tapering end side which are perpendicular to axis of rotation of swivelling joint and where the lugs of female part of swivelling joint are attached.

70. The direction of the twist or bend given to the flap arm with tapering end of Type B. This is the modified form of the earlier type B tapering end.

71. Depicts the actual direction of movement of the axis of rotation of swivelling joint, as the flap arm moves from 0° to 90° three positions. 71T shows top portion and 7 IB shows bottom portion of flap ana

72. The first component of the actual movement of axis of rotation of swivelling joint because of which the swivelling joint moves around itself, where 72T gives movement on top portion and 72B on bottom portion of swivelling joint.

73. The second component of the actual movement of the axis of rotation of swivelling joint due to which the flap moves to make an angle with the flap arm, where 73T gives movement on top portion and 73B on bottom portion.

74. The total angle made by the flap with the flap arm due to the sequencing mechanism as a whole. This angle changes in a sequenced manner due to programmed action of tapering end side.

75. The movement of the axis of rotation of swivelling mechanism when flap arm moves

76. The movement of axis of rotation of swivelling mechanism when flap arm moves from 45° to 90°.

77. The movement of second component 73 when flap arm moves from 0° to 45°.

78. The movement of the second component 73 when flap arm moves from 45° to 90°.

79. Male part has external screw threads and is at end of flap extension, forms its integral part.

80. Female part is ring shaped with internal screw threads.

81. Square type screw threads (Heavy duty threads).

82. Arrow showing the female part is brought near the male part on the flap extension.

83. Arrow showing that female part is engaged fully on to the screw threads of the male part, to form the swivelling joint.

84. The length of the lugs on the female part, must be such that it stays clear of the flap arm when its fully retracted.

85. The gaps formed between the screw threads to allow the passage of lubricant.

86. Internally drilled passages, to allow passage of lubricant.

87. Lubricating point, to allow points to be lubricated by an external lubricating rig.

88. The fastner used is common to all joints.

89. Swivelling joint.

90. Lugs with holes on the female part.

91. Bellcrank having an arm and lever, and moves around the fixed center (can be imagined as a flap arm with the lever for actuating or interconnecting)

92. The movement of the lever of bellcrank.

93. The length of the levers which is the same for both bellcranks.

94. The levers of bellcrank are parallel to each other

95. Straight interconnect tie-rod.

96. Offset interconnect tie-rod

97. The imaginary straight line joining the extreme points of lever in the initial and final moved position of lever.

98. The actual movement of the tie-rods as it moves with the bellcrank, which is quite less.

99. The distance between the imaginary straight line 97 and spar (or the neighbouring components), which has to be kept less to allow placement of other components.

100. Centre of bellcrank, which is fixed to the structure .

101. Lever of the bellcrank 102. Actuator, which can be a hydraulic actuator or. screw jack.

103. The fixed end of actuator, connected to the structure.

104. The movable end of the actuator connected to the lever.

105. The imaginary straight line formed by the three points which are fixed point of actuator and extreme end of lever is initial and final positioa

106. The movement of the actuator as it moves with bell crank and this is quite less.

107. The distance between the straight line 105 and spar, which has to be kept less as possible

108. Shank portion of the fastner, which has a more bearing surface.

109. The threaded portion of fastner.

110. The head of fastner, which is of flat shape with more surface area.

111. The hexagonal slat provided on the head, for tightening the fastner.

112. Flap position sensor (or skew sensor), which sensor the movement of the flap arm

113. Stator or the stationary part of the skew sensor which is fixed on the tip of the support bracket.

114. Rotor or the movable part of the skew sensor which moves with the flap arm movement.

115. The hexagonal shaped stud which engages with hexagonal slat on the fasner.

116. The surface on the tip of the support bracket on which, the stator portion of skew sensor is fixed.

201. Leading edge slats.

202. First flap arm from inboard (shown by free standing arrow)

203. Second flap arm from inboard (shown by freestanding arrow).

204. Third flap arm from inboard (shown by freestanding arrow).

205. Fourth flap arm from inboard (shown by freestanding arrow).

206. Inboard side leading edge slats.

207. Outboard side leading edge slats.

208. Actuating lever, which is a part of actuating flap arm

209. Interconnect lever, which j§ a part of interconnect flap ana

210. Interconnect tie-rod, which is straight in shape.

211. Hydraulic actuator, which is of an conventional type.

212. Ball joint at the eye end, which is used on both the actuator and interconnect tie-rod.

213. The bracket for holding the fixed end of the hydraulic actuator. 214. Angulating mechanism of leading edge slats.

215. Sequencing mechanism of leading edge slats.

216. Front spar of the wing.

217. The movement of the actuating lever.

218. Interconnect hinge and bolt assembly, which connects the slats end to end.

301. Inboard side trailing edge flap, which is parallel to lateral axis or straight in shape.

302. Outboard side trailing edge flap, which is at an angle to lateral axis.

303. First flap from inboard (shown by freestanding arrow)

304. Second flap from inboard (shown by freestanding arrow)

305. Third flap from inboard (shown by freestanding arrow)

306. Fourth flap from inboard (shown by freestanding arrow).

307. Actuating and interconnect flap ana

308. The actuating lever part which is connect to the screw jack and forms a part of actuating and interconnect flap ana

309. The lug which performs the functions of interconnect lever and is a part of actuating and interconnect flap ana

310. Interconnect lever

311. Screw jack (entire assembly)

312. Ball screw

313. Ball nut

314. Universal coupling

315. Bearing

316. Torque tube

317. Sequencing mechanism of trailing edge flap

318. Flap extension on inboard flap

319. Flap extensions on outboard flap

320. Rear spar of the wing

321. Landing gear beam, which holds the landing gear.

322. Direction of movement of actuating lever.

323. 'Z' shaped interconnect tie-rod.

324. Low speed aileron, which is used during lower airspeeds.

325. High speed aileron, which is used during higher airspeeds. 401. Aft flap, which is placed after the fore flap on trailing edge. 402. Inboard side aft flap arm, which is same as flap arm of inboard main flap (fore flap)

403. Outboard side aft flap arm, which is_. same as flap arm of outboard main flap.

404. Aft flap, sequencing mechanism, which is same as main flaps.

405. Aft flap, flap extension which is same as main flaps.

406. Aft flap, flap arm support bracket which is same as main flaps.

407. The aft flaps actuating flap arm, which receives input from the main flaps flap ana

408. Aft flap's actuating tie-rod, which is connected to the main flap's flap ana

409. Lever made on end of main flap ana

410. Lug on the aft flap arm (acutating flap arm of aft flap)

411. Arrow shows the movement of the lever on the main flap arm in the initial and final position

412. Arrow shows the movement of the lug on aft flap's actuating flap arm in initial and final positioa

413. The imaginary straight line joining the points on extreme positions of the lever and also the points on extreme positions of the lug.

501. Duct

502. The open-bulbed shape at end of the duct, with larger diameter.

503. The open bulbed shape at the end of the duct, with smaller diameter (smaller than that given in 502, so that both of them can go inside each other)

504. Seals or O-rings, which are made of heat resisting materials.

505. The two open-bulbed shapes at end of the ducts are forced inside each other as shown by arrow.

506. The initial position of the duct.

507. The duct can move at an angle of 45° from the initial position, in all directions in three dimensional space, as shown by the arrow.

508. The total angle of movement is 90° (as given by two extreme end positions)

509. Gives the center the imaginary sphere, from which the open-bulbed shape at the end of the duct is supposed to be formed.

510. The distance after the center of imaginary sphere, after which it opens up to form the open-bulbed shape.

511. The connecting duct, whose length is same as the respective flap arms on the leading edge. 512. The total angle through which the duct moves is 90°, which is same as movement of flap ana

513. The angle of 30° made by the lateral axis to the connecting duct with flaps in full retracted position, which is same as flap arm.

514. Bend given to the duct in a peculiar fashion, at the fixed end of the connecting duct.

515. The boh and nut installed exactly paralled to the axis of rotation of angulating mechanism, due to which the connecting duct moves in the same way as the flap arms.

516. The portion of the heating duct which is exposed to the airflow and hence made parallel to longitudinal axis.

517. Heating duct, (anti-ice) inside the slats.

518. Anti-ice, supply duct.

519. Coupling joint, which is small lengthed and cylindrical shape and can be slided on the ends of the duct.

520. Arrow shows how easily it can slided off to disconnect the joint, for easy removal of slats.

521. Shown in arrows the direction of flow of anti-ice hot air inside the ducts.

522. Connecting duct, supplies air from supply duct to heating duct inside slats.

Claims

C L AI M S

1. I claim that all the flap arms (6) on each wing on the leading edge flaps (41) or trailing edge flaps (42) have similar lengths and directional orientations (28) of the sector swept by them, also they operate synchronously; are parallel to each other and they have a paraUelogramming effect as they move the flaps.

2. As in claim 1, also the two interconnect levers on the flap arms also operate on the same principle, that they have similar length and directional orientations of the sectors swept, also they operate synchronously; are parallel to each other and have a paraftelogramming effect as they move.

3. I claim that the straight shaped flap arm (6) can be used on swept back wing (13) or any kind of wing with some portion at an angle to the lateral axis (1), whereas the 'L' shaped flap arm (38) can be used on rectangular wing (12) or any kind of wing with some portion parallel to lateral axis (1)

4. As in claim 3 and the flap extension (39) can be used with any kind of flap arm, is fixed permanently on the flap body such that it is always parallel to the longitudinal axis (2), where the combination of the flap arm and flap extension gives the least drag from this assembly.

5. I claim that the flap arm sweeps a sector (14) of 90 degrees as it moves between its two extreme position, hence the directional orientation (28) of this sector will be such that the flap arm in its retracted position is 30 degrees (29) as measured from one side of the lateral axis and in its extended position is 60 degrees (30) as measured from the opposite side of lateral axis (1).

6. As in claim 5 when this flap arm moves, the flaps will have a less lateral displacement (31) or sideways movement.

7. I claim that the extreme end (moveable part) flap arm in retracted position and the extreme end (moveable part) of flap arm in extended position are both joined by a imaginary straight line (49)

8. As in claim 7 the direction towards which the flap body (45) moves, that side (47) of the flap will have its plan form shape (looking from top) modified such that it is parallel to this imaginary line (49) due to which there is no void space formation and the flap fit properly on the corresponding wing shape.

. As in claim 7, to allow for lateral displacement (31) of the flaps, there is a gap (50) provided between the perpendicular side (48) of the flaps and corresponding wing shape.

10. I claim the angulating mechanism (59) is an integral part of the flap arm, where its fixed end is connected to the support bracket (27), having its axis of rotation (53) inclined to the vertical axis (3) and making equal angles with longitudinal (2) and lateral axis (1).

11. As in claim 10 when the flap arm moves, it also makes an angle (55) with the plane of the wing, where this angle (55) is directly proportional to the angle of inclination (54) of the axis of rotation (54).

12. As in claim 10, if the axis of rotation (53) of the angulatin ^mechanism is inclined to an angle exactly opposite in direction and same in magnitude, then the flap arm moves in the opposite direction to make an angle (60) with the plane of the wing.

13. I claim the sequencing mechanism (61) which is placed at the extreme end of the flap arm, which moves around the center and it consists of an tapering end (62) and swivelling joint (89).

14. As in claim 13 the tapering end (62) is the unique taper shape given to the extreme end of the flap arm, where the total angle made by the flaps with the flap arm will be equal to the angle (66) made by the tapering end with the vertical axis and the angle (68) made by the axis of rotation of swivelling joint with plane of the flap arm will determine the type of sequencing or pre-programmed movement given to the flaps.

15. As in claim 13 the swivelling joint (89) consists of a male part (79) having external threads which is an integral part of flap extension and the female part (80) which in ring shaped having internal threads, also has lugs (90) for attaching it to the tapering end.

16. As in claim 13 and the screw threads (81) on the male part (79) of swivelling joint (89) are cut more deeper than the female part (80) so that when engaged a gap (85) is formed between them, due to which when lubricated at one point the lubricant passes through these gaps to lubricate the entire screw threads.

17. As in claim 13 and the tapering end of type A (63) and tapering end of type B (64).

18. I claim that the extreme end points of the interconnect lever of the flap arm (91) in retracted and extended position can be joined to form an imaginary straight line (97),

19. As in claim 18 and if these imaginary straight lines (97) of the two interconnect levers are parallel to each other, then a 'Z' shaped interconnect tie rod (323) is used to connect both of these interconnect levers.

20. As in claim 18 and if these imaginary lines (97) form a straight line then a straight shaped tie rod (95) is used to connect both the interconnect levers (91).

21. I claim the actuating flap arm (91) with an actuating lever, where only one of these is placed on each with, on either the leading edge or trailing edge flaps, on preferably the most inboard side of the flap to actuate or move the flaps as a whole.

22. As in claim 21 and also the points an the fixed end of the actuation system (103) and the points on its moveable end (104) with actuating lever in two extreme positions will form a straight line (105).

23. I claim that the flap skew sensor (112) stator or stationary part (113) is installed on the extreme tip of the support bracket (116), on a point which is on the axis of rotation (53) of angulating mechanism of the flap arm and hence senses the flap arm movement.

24. As in claim 23 and the rotor (114) of the flap skew sensor has an hexagonal shaped stud (115) which exactly fits into the matching slot (111) made on the fastner fitted an the flap arm, by which the rotor moves exactly as the flap ana

25. I claim the connecting duct (522) which is similar to the flap arms on leading edge slats in many respects which are the length (511); the directional orientation of the sectors swept ; angular movement of 90 degrees (512) and also the axis of rotation of the duct is same as that of angulating mechanism, where only one in installed on the most inboard side of each wing.

26. As in claim 25 and the coupling joint (519) connects all the heating ducts (517) inside the slats end to end, so that the anti-ice air supplied by the connecting duct passes through the entire length of the slats.

27. As in claim 25 and also the peculiar bend (514) given to the connecting duct (522) and the boh and nut (515) installed exactly parallel to axis of rotation of angulating mechanism, due to which the connecting duct moves in the same way as the flap arms.

28. I claim the components of the aft flap like it support bracket (406), flap arm (402 or 403), sequencing mechanism (404) and flap extensions (405) which have exactly the same constructional and operational principles as the flap arm (6 or 38) of the fore flap but with the only difference that the aft flap components are quite smaller in size than that of the fore flap.

29. As in claim 28 the aft flap actuating tie rod passes from the outside on the side ( breadthwise side of fore flap) of the fore flap, hence no holes or cavities have to be made on the body of fore flap, to pass the aft flap tie rods.

30. I claim the flap support bracket (27), to which the flap arm (6) in connected and forms the center (10) around which the flap arm moves.