US2312546A - Airplane aileron - Google Patents

Description

March 2, 1943- J. G. HAZARD ETAL 2,312,545

AIRPLANE AILERON Filed June 6, 1941 2 Sheets-Sheet 1 March 2, 1943.

J. G. HAZARD EI'AL AIRPLANE AILERON Filed June 6, 1941 2 Sheets-Sheet 2 Patented Mar. 2, 1943 AIRPLANE AILERON John G. Hazard and Albert E. Arslan, Los Angeles, Calif., assignors to Vultee Aircraft, Inc., Vultee Field, Calif., a corporation of Delaware VApplication June 6, 1941, Serial No. 396,816

6 Claims.

The present invention relates generally to airplane ailerons. More particularly the invention relates to that type of airplane aileron which extends longitudinally of, and is hinged to, the trailing edge of the wing of the airplane and is statically and dynamically balanced about the hinge line or axis.

In a conventional or standard aileron the hinge line is generally located behind the leading edge a distance approximately equal to one-fifth the distance between the leading and trailing edges of the aileron, i. e., a distance corresponding to approximately 20% of the cord of the aileron and it is customary to provide a longitudinally extending primary load carrying beam which is disposed rearwards of the hinge line or axis. It is also customary to employ nose ribs on the forward face of the beam and tail ribs on the aft side or face in order to establish the desired contour. The nose ribs are covered by a formed metallic skin, and a trailing edge piece is employed to connect the aft ends of the tail ribs. The structure comprising the primary load carrying beam, the nose ribs, tail ribs, formed metallic skin and trailing edge piece is covered by doped fabric. In order statically and dynamically to balance the aileron about the hinge line ballast pieces of lead or like material are employed and these are placed within the formed metallic skin around the nose ribs. An aileron of the aforementioned type is objectionable from the standpoint of maintenance because of the fragility of the doped fabric covering. If a metallic skin is employed as the main covering instead`of a covering of doped fabric in order to eliminate fragility and provide a more sturdy construction or design the weight of the aileron as a whole is essentially increased and it is necessary to employ a great amount of ballast for the purpose of maintaining proper balance of the aileron about its hinge line.

The principal object of the invention is to provide an airplane aileron which is an improvement upon and has certain advantages over a standard or conventional aileron having either a doped fabric covering or a covering in the form of a metallic skin; by reason of the fact that it includes a metallic skin but is so designed and constructed that it has the proper balance about its hinge line without the use of any appreciable amount of ballast in its nose part. The improved aileron has the lightness of a fabric covered aileron while at the same time it possesses the same sturdiness and rigidity as the heavier conventional aileron with a metallic skin covering. In general the improved aileron is characterized by the fact that the longitudinally extending main load carrying beam is located in front of the hinge line or axis for balancing purposes and is shaped to form a nose former.

Another object of the invention is to provide a statically and dynamically balanced airplane aileron of the type under consideration which not only is light and durable but also comprises or embodies fewer parts than standard or conventional ailerons.

A further object of the invention is to provide an airplane aileron in which the ribs are of onepiece design.

A still further object of the invention is to provide a statically and dynamically balanced airplane aileron of the type under consideration which includes simple and novel intercostals for reenforcing and cross connecting certain of the ribs and supporting hinge plates.

Other objects of the invention and the various advantages and characteristics of the present aileron will be apparent from a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by claims at the conclusion hereof.

In the drawings which accompany and form a part of this specification or disclosure and in which like numerals of reference denote corresponding parts throughout the several views:

Figure 1 is a perspective view of an airplane Wing having an aileron embodying the invention;

Figure 2 is an enlarged fragmentary perspective view of the aileron, illustrating in detail the construction and design of the main or primary load carrying beam and the one-piece cross ribs;

Figure 3 is a vertical transverse section through the central portion of the aileron showing the manner in which the upper and lower metallic skin sections are riveted in place and illustrating in detail the construction of the central hinge between the aileron and the wing;

Figure 4 is a fragmentary front View of the central portion of the aileron;

Figure 5 is a horizontal section on the line 5-5 of Figure 3; and

Figure 6 is a perspective view of one of the intercostals.

The aileron which is shown in the drawings constitutes the preferred form or embodiment of the invention. It is illustrated in connection with one of the side wings W of an airplane A andzserves in conjunction with a complemental aileron (not shown) onl the other side of the airplane as a medium for enabling the pilot to roll the airplane A on its longitudinal axis 'I'he wing W extends outwards from one side of the fuselage of the airplane A and is of conventional design or lconstruction. It tapers outwards both verticallyand horizontally and has a cutout or recess in its trailing edge for the aileron.

'I'he aileron is hinged, as hereinafter described,

to swing upwards and downwards about a substantially horizontal hinge line and is essentially of unitary design. It is of all metal construction and as its primary or principal parts comprises a longitudinally extending primary load carrying beam 1, a series of laterally spaced ribs 8, 3, I Il, II, I2, I3, I4, I5, I3, I1, I8, I3, 20 and 2| an upper, metallic skin section 22 and a lowenmetallic skin section 23. As shownin Figure 1, the aileron tapers outwards both vertically and horizontally and its trailing edge is aligned with 'the trailing edge of the 'wing W when the aileron is in its normal position. The beam 1 not only serves as the main or primary load carrying element of the aileron lbut also as a nose former. It is dis.

posed in front of the hinge line, as hereinafter described, and operates together with an extremely small amount of ballast statically and dynamically to balance the aileron about the hinge line. 'The upper portion of the beam is curved or bent rearwards and embodies along its longitudinal edge a full length integral depending flange 24. The lower portion of the beam 1 is rearwardly curved, as shown in Figures 2 and 3, and has along its longitudinal edge a full length upstanding integral flange 25. The beam is preferably of one-piece design and is formed of any suitable metal. It extends from one end ofthe aileron to the other and has smooth inner and outer faces. The two flanges 24 and 25 serve as reenforcing means for the beam and are disposed in parallel relation. 'I'he ballastis in the form of small pieces 1" of lead or like material and these are located between the ribs and are connected by screws to the front inner face of" the front portion of the beam.

The ribs are each of one-piece design and are formed of any suitable metal. They are semipear shaped, as shown in Figures 1 and 3, and have substantially continuous integral right angle flanges 26 around their margins. The front portions of the ribs are curved conformable to, and abut directly against, the inner face of the primary load carrying beam 1. Rivets 21 extend through the beam and the front portion of the flanges 26 and serve rigidly to connect the beam to the ribs. The upper forward portions of the ribs have notches 23. 'I'he depending flange v24 of 'the beam fits within these notches, as shownjin Figures 2 and 3. For the purpose of connecting the flange 24 to the ribs angle bar type clips 29 are provided. These clips correspond in number to and are associated respectively with the ribs and consist of vertically extending rear legs 30 and vertically extending front legs 3i. The rear legs f lt against and are riveted to the portions` of theribs that define the notches 28 and the other legs, i. e., the legs 3i, extend at right angles to the legs 30 and abut against and are riveted to the flange 24. 'I'he upper rear portions of the ribs slope downwards and rearwards and the lower portions of the ribs slope upwards and rearwards, as illustrated in Figures 2 and 3. 'Ihe front or forward lower portions of the ribs have notches 32 for accommodating the upstanding flange at the bottom margin of the primary load carrying beam 1. Such flange is anchored v or connected to the ribs by way of angle bar type clips '33. The latter consist of rear legs 34 which fit against and are riveted tothe front lower portions of the ribs, and laterally extending legs 35 which abut against, and are riveted to. the flange 25.

'I'he upper skin section 22 extends from one end of the aileron to the other and serves as a covering for the top or upper portion of the aileron. The central and rear portions of the upper skin section 22 overlie the central and rear upper portions of the flanges l28 and are connected by rivets 38 to such portions of the flanges. The

' front'portion of the upper skin section 22 is bent or curved downwards in conformityl with the upper portion of the beam 1 and laps or abuts directly against, such portion of the beam. Certain of the rivets 21 extend through the front portion oi the upper skin section 22 and the contiguous upper portion of the beam 1 and serve to hold the front portion of the skin 'in ilxed from one end of the aileron -to the other.

relation with the beam.. The front edge of the upper skin section terminates at a point slightly above the cord line of the aileron. The lower skin section 23, like the upper section, extends It is formedof any suitable sheet metal and is substantially imperforate. The -central and rear portions of the lower skin section underlie and abut directly against the central and. rear lower portions of the rib flanges 26 and are secured to such portions of the anges by way of rivets 38. The front portion of the lower skin section 23 extends around and is curved conformably tothe lower portion of the primary load 'carryingY beam 1. It abuts directly against said lower portion of the beam and is flxedly connected to the latter by way of certain of the rivets 21. The front edge of' thel lower section and the front edge of the upper section are in lapped relation. The rear or trailing margins of the upper and lower skin sections project beyond therear ends of the ribs and are secured together in lapped relation by-rivets l40. The front portions of the flanges 23, that is, the portions in front of the notches 28 and 32, are inwardly offset a distance corresponding to the thickness of the primary load carrying beam 1. Due to the offset the upper and lower portions of the outer face of the beam are coplanar with the adjacent outer face portions of the flanges and the two skin sections are hence smooth and embody no step formation.

The ribs I4 and I5 are located in the central portion of the aileron, as shown in Figure. 1, and are positioned closer together than the adjoining ribs. They are so constructed that the marginal flanges thereof project or extend away from one another. An intercostal 4I in the form of a metallic plate or stamping extends between and serves to cross connect the front ends of the ribs I4 and I5. It is located behind the hinge line of the aileron and embodies a pair of forwardly extending side -flanges 42, a forwardly extending top-flange 43 and a forwardly extending bottom flange 44. The side flanges abut against the front portions of the ribs I4 and I5 and are riveted or otherwise flxedly secured in place. The top flange 43 underlies and abuts against the superjacent portion of the upper skin section 22 and is connected to the latter by rivets 45. The

bottom flange 44 of the intercostal 4I abuts against the subjacent portion of the lower metallic skin section 23 andis connected to such portion by way of rivets 46. A metallic angle bar 41. extends across and is connected to the top margin of the intercostal 4|. This angle bar embodies a top rearwardly extending leg which isv riveted to the superjacent portion of the skin section 22. The bottom margin of the intercostal 4I is reenforced by an angle bar 48 and this, as

shown in Figure 3, extends across the rear face portion of the bottom margin of the intercostal and has a rearwardly extending leg or flange which abuts against and is riveted to the subjacent portion of the lower skin section 23. The intercostal 4I serves not onlyxto cross connect the ribs I4 and I5 but also to support a pair of vertically extending hinge plates 49, The latter are positioned in laterally spaced relation in front of the intercostal 4I and have right angle rear flanges 50 which t against and are bolted to the side portions of the intercostal. Aligned holes 5I are formed in the lower portions of the plates 49, as shown in Figure 3. The central portion of the aileron is hinged to the adjacent portion of the wing W by way of a hinge bracket 52. This bracket is fixed to the rear aft spar of the wing (see Figure 3) and has a rearwardly and downwardly extending arm 53. This arm extends into the front central portion of the aileron through a rectangular hole 54 in the primary load -carrying bottom 1 and U-shaped cutouts 55 n the front portions of the upper and lower skin sections 22 and 23. The lower end of the arm 53 of the hinge bracket 52 ts between the lower portions of the hinge plates 49 and is pivotally connected to such plates by way of a pin 56 which extends through a hole in the lower end of the arm and is mounted in the holes 5I. The hinge plates 49 and the arm equipped hinge bracket 52 constitute a hinge whereby the aileron is permitted to swing upwards and downwards. The pin 56 constituting the hinge line of the aileron is located behind the main or primary load carrying beam I and the beam ls so proportioned as to weight that it serves statically and dynamically to balance the aileron about its hinge line.

The ribs 9 and l0 are located at the outer end of the aileron and are spaced apart the same distance as the ribs I4 and I5. They are cross connected by way of an intercostal (not shown) and the latter is the same in design as the intercostal 4I and carries a pair of hinge plates which, to'- gether with a hinge bracket (not shown), constitute a hinge for the outer end of the aileron.

The ribs I 9 and 20 are located adjacent the inner end of the aileron and are cross connected by way of an intercostal (not shown). Such intercostal is the same in design and construction as the intercostal 4I and carries a pair of laterally spaced hinge plates (not shown) which are like the hinge plates 49 and together with an arm equipped bracket on the trailing portion of the wing constitute a hinge for the inner end of the aileron.

The aileron is shifted or .controlled by way of a push and pull rod 51. The latter extends transversely through the outer rear portion of the wing W and has its rear end pivotally connected to the aileron by way of a pair of pivot plates 58. The latter are welded to, and project forwardly from, a curved plate 59. Such plate, as shown in Figure 2, is located at one side of the beam opening 54 and is bolted to the front portion of the upper skin section 22.

The herein described aileron, due to its construction and design, is both light in Weight and durable. It is essentially statically and dynamically balanced by reason of the arrangement and design of the primary load carrying beam I and requires but a minimum amount of additional ballast for purposes of properly balancing it about the hinge line. The beam has a threefold purpose in that it constitutes the main load carrying element of the aileron, serves as a nose former and in addition assists in statically and dynamically balancing the aileron. By reason of the fact that the ribs are of one-piece design the aileron as a whole has but a limited or small number of parts and hence may be produced at a low and reasonable cost. The aileron is characterized by the fact that it is sturdy and rigid and is much lighter in weight than a standard or conventional aileron having either a doped fabric skin or a metallic skin.

Whereas the invention has been described in connection with an aileron it is to be understood that it is capable of being embodied in any type of airfoil, such, for example, as an airplane elevator or rudder. It is also to be understood that the invention is not to be restricted to the details set forth since they may be modified within the scope of the appended claims without departing from the spirit and scope of the invention.

Having thus described the invention what we claim as new and desire to secure by Letters Patent is:

1. An airfoil comprising a longitudinal beam extending from one end of the airfoil to the other curved transversely and forwardly so that it is of U-shaped cross section and serves as a nose former and designed and proportioned to form the main or primary load carrying member of the airfoil, a plurality of laterally spaced unitary rearwardly tapered ribs disposed behind the beam and having convex U-shaped nose portions curved conformably to and fitting within and secured to said beam, and a covering over the ribs.

2. An airfoil comprising a longitudinal substantially full length beam curved transversely and forwards so that it is of U-shaped cross section and serves as a nose former and designed and proportioned to form the main or primary load carrying member of the airfoil, a series of laterally spaced marginally anged rearwardly tapered one piece ribs extending rearwardly from, and connected to, the beam, a skin section serving to cover one side of the airfoil and having its central and rear portions tting against and secured to the adjacent portion of the rib flanges and its front portions extending around and secured to a portion of the beam, and a complemental skin section serving to cover the other side of the airfoil and having its central and rear portions fitting against and secured to the adjacent portions of the rib flanges and the front portion thereof fitting around and secured to the remaining portion of the beam.

3. An airfoil comprising a longitudinally extending full length metallic beam curved transversely and forwards so that it is of U-shaped cross section and serves as a nose former, and designed and proportioned to form the main or primary load carrying member of the airfoil, a series of laterally spaced marginally flanged onepiece rearwardly tapered ribs disposed behind the beam and having convex U-shaped nose portions thereof shaped conformably to, and tting within and secured to, the beam, a skin section serving to cover one side of the airfoil and having the. central and rear portions thereof fitting against and secured to the adjacent-portions of the rib flanges and its front portion curved around and secured to a portion oi' the beam, and a complemental skin section arranged to cover the other side of the airfoil and having the central and rear portions thereof fitting against and secured to the adjacent portions of the rib flanges and its front portion curved around and secured to the remaining portion of the beam.

4. An airfoil comprising a longitudinally extending substantially full length beam curved transversely and forwards so that it is of U- shaped cross section and serves as a nose former, designed and proportioned to form the main or primary load carrying member of the airfoil, and having integral inturned flanges along its lon'- gitudinal margins, a series of one-piece laterally spaced ribs disposed behind the beam and having convex U-shaped nose portions thereof shaped conformably to, and fitting within an-d secured to the beam, and provided with marginal notches for accommodating the beam flanges, angle type clips extending between and connected to the notch defining portions of the ribs and the adjacent portions of the flanges, and a covering over ribs.

5. A movable airfoil having hinge means in theI front portion thereof whereby it is supported for swinging movement about a longitudinally extending hinge line, and comprising a longitudinally extending substantially full length beam `positioned in front of the hinge line, curved transversely and forwards so that it is of U-shaped cross section and serves as a nose former, and designed and proportioned to form the main or primary load carrying member of the airfoil and also to assist in statically and dynamically balancing the airfoil about said hinge line, a plurality of laterally spaced unitary rearwardly tapered cross ribs disposed behind the beam and having convex U-shaped nose portions curved conformably to, and fitting within and secured to, said beam, and a covering around the beam and ribs.

6. Amovable airfoil comprising a longitudinally extending substantially full length beam curved transversely and forwards so that it is of U- shaped cross section and serves as a nose former and designed and proportioned to form the main or primary load carrying member of the airfoil, a plurality of laterally spaced unitary ribs disposed behind the beam and having U-shaped nose portions curved conformably to, and fitting within and secured to, said beam, an intercostal positioned behind the beam and between two of the ribs and having a hinge plate on the front face thereof, and a covering or skin over the ribs, said beam having an opening therein in front of the hinge plate for accommodating a hinge arm.

r JOHN G. HAZARD.

ALBERT E. ARSLAN.

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