Patent Description:
An aircraft may include several control surfaces configured to affect the yaw, roll and pitch of the aircraft during flight. Such control surfaces may include, for example, ailerons to affect the roll about a longitudinal axis, a rudder to affect the yaw about a vertical axis and an elevator to affect the pitch about a lateral axis, each axis being with respect to a coordinate system fixed to the aircraft. Additional control surfaces include trailing edge flaps configured to affect the lift of a wing, leading edge slats configured to affect the stall speed of a wing and spoilers, generally located adjacent to and forward of the trailing edge flaps and configured to disrupt the airflow over a wing surface to reduce lift or to increase drag. Control surfaces are typically airfoil-like components configured to alter the flow of air about the wings or tail structure of the aircraft. As such, an individual control surface is generally simple in shape, having one or more of a leading edge, a trailing edge, a pressure side and a suction side. Notwithstanding the simple shape, a control surface or the airfoil-like component thereof, must possess sufficient structural integrity to withstand the forces applied to it during use over the operational life of the aircraft. Control surfaces exhibiting low weight and high strength may be fabricated using hollow airfoil-like bodies having stringers and solid material sections positioned where the aerodynamic forces tend to present maximal loads.

Resin Pressure Molding (RPM) may be used to form complex 3D structures from composite materials. These structures usually contain little to no fasteners (smooth). They also offer high strength and stiffness to weight ratio assemblies. These properties are ideal for air vehicle control surfaces. However, the interface between at least some control surfaces and the vehicle can be subject to high wear and can experience high loads. Therefore, a need exists to efficiently attach the control surface structure to the air vehicle interface without sacrificing the weight or strength benefits of the composite material, nor the aerodynamically smooth properties of the RPM technology.

<CIT> relates to a method and apparatus for a one-piece composite bifurcated winglet for an aircraft. According to its abstract, the composite winglet comprises a first blade, a second blade, and a root region. The root region is co-cured with the first blade and the second blade to form the composite winglet. The root region is configured to receive an attachment system for attaching the composite winglet to a wing of the aircraft.

<CIT> relates to a winglet attach fitting for attaching a split winglet to an aircraft wing. According to its abstract, the method includes fastening an upper winglet to an upper winglet attachment portion of a wing attach fitting having a wing attachment portion. The method further includes fastening a lower winglet to a lower winglet attachment portion of the wing attach fitting. The method additionally includes fastening the wing attachment portion to the wing tip using tension fasteners installed from an inboard side of the wing tip to secure the split winglet to the wing.

<CIT> relates to composite material structures that include fittings also made of a composite material and to methods of manufacturing composite material structures and fittings.

<CIT> relates to methods and apparatus for aircraft operating in conjunction with a fuselage and a wing. According to its abstract, the fuselage may have at least one hole defined therethrough. A spar may be disposed through the hole and extend into at least a portion of the wing and at least a portion of the fuselage. The spar may connect the fuselage to the wings.

<CIT> relates to parts forming the structure of an aircraft, and in particular the tip fairing of a horizontal airfoil. According to its abstract, the tip fairing comprises stiffening elements and a skin covering the stiffening elements. The stiffening elements comprise a central web and two flanges located at the tips of the web, with contact between the skin and the stiffening elements being made through the flanges of the stiffening elements. The tip fairing is manufactured from a composite material and from a single part.

<CIT> relates to a blade structure for use in a windmill.

<CIT> relates to rotor blades for use with a wind turbine.

An aerostructure assembly is presented herein. Both the configuration of such an aerostructure assembly and the fabrication of such an aerostructure assembly are within the scope of this Summary.

According to a first aspect of the invention, an aerostructure assembly is as defined in claim <NUM>.

According to another aspect of the invention, a method of fabricating an aerostructure assembly is as defined in claim <NUM>.

The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. An understanding of the present invention may be further facilitated by referring to the following detailed description and claims in connection with the following drawings. Reference to "in accordance with various embodiments" in this Brief Description of the Drawings also applies to the corresponding discussion in the Detailed Description.

The various embodiments addressed herein each may be characterized as being in the form of an "aerostructure". The term "aerostructure", as used in this disclosure, means a unit, component, section, or any portion or combination of portions of an aircraft or other vehicle that is capable of flight, where "vehicle" includes any structure that is used to transport one or more payloads of any appropriate type (e.g., cargo, personnel) and including without limitation manned or unmanned flight vehicles such as an aircraft. Representative aircraft in accordance with the foregoing includes without limitation airplanes, unmanned arial vehicles, helicopters, and the like. An aerostructure in accordance with this disclosure may be in the form of a rudder, elevator, aileron, fin, wing tip, flap, slat, spoiler, trim tab, stabilizer, or external antennae for a flight vehicle, as appropriate.

<FIG> illustrates an aircraft <NUM> having a variety of control surfaces disposed about the wings <NUM> and the tail section <NUM> of the aircraft, while <FIG> illustrates a wing <NUM> having a plurality of spoilers <NUM> disposed along an upper surface <NUM> of the wing <NUM>, with each of the plurality of spoilers <NUM> illustrated in a deployed position. Referring specifically to <FIG>, the variety of control surfaces typically used on the wings <NUM> of the aircraft <NUM> may include, for example, an aileron <NUM>, a trailing edge flap <NUM>, a spoiler <NUM>, disposed adjacent to and forward of the trailing edge flap <NUM>, and a leading edge slat <NUM>. Similarly, the variety of control surfaces typically used on the tail section <NUM> of the aircraft <NUM> may include, for example, a rudder <NUM> and an elevator <NUM>. While the foregoing description of the variety of control surfaces generally refers to each control surface as a single component, it will be appreciated that, in various embodiments, each individual component, e.g., the spoiler <NUM>, may be a single component within a plurality of like components, e.g., the plurality of spoilers <NUM>, as illustrated in <FIG>. For example, with reference to <FIG>, the plurality of spoilers <NUM> may, in various embodiments, include a first spoiler <NUM>, a second spoiler <NUM> and a third spoiler <NUM>. In various embodiments, each one of the plurality of spoilers <NUM> includes an upper surface <NUM> and a lower surface opposite the upper surface <NUM>, a trailing edge <NUM>, and an inboard end <NUM> (or a first end) and an outboard end <NUM> (or a second end).

An aerostructure assembly is illustrated in <FIG> and is identified by reference numeral <NUM>. The aerostructure assembly <NUM> includes an aerostructure <NUM> and a coupling assembly <NUM>. The aerostructure <NUM> may incorporate one or more control surfaces for a flight vehicle (typically movable relative to the flight vehicle), or could incorporate one or more aerodynamic surfaces for a flight vehicle (e.g., a stationary surface relative to the flight vehicle). Representative control surface applications for the aerostructure <NUM> include without limitation rudders, elevators, ailerons, fins, wing tips, flaps, slats, spoilers, trim tabs, stabilizers, and the like. Representative aerodynamic surface applications for the aerostructure <NUM> include without limitation a wing tip and external antennae. For at least certain applications the aerostructure <NUM> may be characterized as an airfoil or an airfoil-like structure.

The aerostructure <NUM> may be in the form of a resin pressure molded part (e.g., an integral composite structure; a net-shape composite part). "Integral" means the aerostructure <NUM> is of a one-piece configuration - adjacent portions/components of the aerostructure <NUM> are not separately formed and are not separately attached together. Stated another way, no fasteners are utilized to define the aerostructure <NUM> itself. The aerostructure <NUM> may also be characterized as being monolithic or as a monolithic part.

Resin pressure molding (RPM) is a closed-molding process that includes delivering a liquid resin into a closed mold in which some, or all, of the fiber reinforcement has been preimpregnated with a resin (e.g., via one or more pre-preg sheets of resin/fibers (e.g., carbon fibers) being positioned in the mold prior to its closure. The mold may include one or more mandrels to accommodate defining one or more open spaces within the article being formed (e.g., the aerostructure <NUM>). A combination of elevated heat and hydrostatic resin pressure may be applied to the mold to cure the article being formed.

The aerostructure <NUM> includes an outer shell <NUM> (e.g., which may have a leading edge <NUM>, a trailing edge <NUM>, a first end <NUM> having at least one opening (including where the entirety of the first end <NUM> is open), and a closed end <NUM>; note that the cross-section of <FIG> is taken where the outer shell <NUM> contacts a second coupling end <NUM> of a coupling <NUM> of a coupling assembly <NUM>, discussed below). The first end <NUM> and the closed end <NUM> are spaced along a first dimension <NUM> (e.g., a "z" dimension). A female receiver <NUM> is disposed within an interior of the outer shell <NUM> and is spaced from the outer shell <NUM>. A plurality of first supports <NUM> extend between the outer shell <NUM> and an outer perimeter of the female receiver <NUM>. One or more of the female receiver <NUM> and the first supports <NUM> may extend from the first end <NUM> to the closed end <NUM> of the outer shell <NUM>. However, one or more of the following may be applicable to the female receiver <NUM>: <NUM>) the female receiver <NUM> could be recessed relative to the first end <NUM> (spaced from the first end <NUM> in the direction of the closed end <NUM>); and/or <NUM>) the female receiver <NUM> could terminate prior to reaching the closed end <NUM> (e.g., an end of the female receiver <NUM> closest to the closed end <NUM> could be spaced from the closed end <NUM>). Each of the first supports <NUM> may have a common length dimension (in the first dimension <NUM>) in relation to the length dimension of the female receiver <NUM> (e.g., each support <NUM> may extend along an entire length of the female receiver <NUM> in the first dimension <NUM>).

An open space or void <NUM> may exist between each adjacent pair of first supports <NUM>. Optionally, foam or another material or combination of materials could be disposed in one or more of the open spaces <NUM> (such a material(s) within the open spaces <NUM> not being defined by the resin pressure molding process that defines the aerostructure <NUM>, for instance filler material <NUM> shown in one of the open spaces of <FIG>). This void can be filled as a secondary process to the RPM process or as a "fly-away tool" applied concurrently to the RPM process.

The coupling assembly <NUM> is separately formed from the aerostructure <NUM>, such that the coupling assembly <NUM> and the aerostructure <NUM> are separate "parts" or "components". The coupling assembly <NUM> includes a coupling <NUM> having a first coupling end <NUM> and a second coupling end <NUM> that are spaced along the first dimension <NUM>. A beam <NUM> of the coupling assembly <NUM> extends from the second coupling end <NUM> in the first dimension <NUM>. The coupling <NUM> and the beam <NUM> may be integrally formed such that the coupling assembly <NUM> is of an integral configuration or structure. Each of the coupling <NUM> and beam <NUM> may be formed from one or more metals, one or more metal alloys, or any combination thereof.

The beam <NUM> of the coupling assembly <NUM> is disposed within the female receiver <NUM> of the aerostructure <NUM> in an assembled/installed configuration for the aerostructure assembly <NUM>. An outer perimeter or surface <NUM> of the beam <NUM> and an inner perimeter/surface <NUM> of the female receiver <NUM> may be of a complementary shape (e.g., an entirety of the outer perimeter <NUM> of the beam <NUM> may be disposed in interfacing relation with the inner perimeter <NUM> of the female receiver <NUM>). <FIG> shows the beam <NUM> as having a dovetail-type profile/configuration (viewed perpendicularly to the first dimension <NUM> in which the beam <NUM> extends). Other configurations for the beam <NUM> could be utilized for the aerostructure assembly <NUM>, such as C-shaped, T-shaped, I-shaped, square-shaped, triangularly-shaped, and the like.

The aerostructure assembly <NUM> may be assembled by sliding the aerostructure <NUM> onto the beam <NUM> such that the beam <NUM> is directed into the female receiver <NUM> of the aerostructure <NUM> and including where the first end <NUM> of the aerostructure <NUM> abuts the second coupling end <NUM> (e.g., the entirety of the coupling <NUM> may be disposed outside/beyond the aerostructure <NUM>). However, a portion of the coupling <NUM> could be disposed within the interior of the outer shell <NUM>, including where such a portion is disposed in interfacing relation with an inner surface of an end portion of the outer shell <NUM>.

An outer perimeter of the coupling <NUM> that is positioned beyond the outer shell <NUM>, and an adjacent portion of an outer perimeter of the outer shell <NUM> of the aerostructure <NUM>, may have a matching profile/shape (e.g., to in effect define a continuous surface) for an exterior of the aerostructure assembly <NUM>. One or more fasteners <NUM> (<FIG>) may be directed through the outer shell <NUM> and into the beam <NUM> to secure the coupling assembly <NUM> relative to the outer shell <NUM> in the first dimension <NUM>. Based upon the above-noted interface between the beam <NUM> and the female receiver <NUM>, and in conjunction with the noted fastener(s) <NUM>, the coupling assembly <NUM> will be retained relative to the aerostructure <NUM> in at least three dimensions/directions (and including within the first dimension <NUM>, a second dimension <NUM> (e.g., a "y" dimension), and a third dimension <NUM> (e.g., an "x" dimension) and including in all dimensions/directions. The above-noted interface between the beam <NUM> and the female receiver <NUM> itself may retain the aerostructure <NUM> relative to the coupling assembly <NUM> in each of the second dimension <NUM> and the third dimension <NUM>, while the one or more fasteners <NUM> may retain the aerostructure <NUM> relative to the coupling assembly <NUM> in the first dimension <NUM>.

<FIG> presents a flight vehicle <NUM> that incorporates the aerostructure assembly <NUM>. Although <FIG> illustrates that the beam <NUM> extends from the first end <NUM> of the aerostructure <NUM> its closed end <NUM>, such may not be required for all applications (e.g., the beam <NUM> could terminate at an intermediate location between the first end <NUM> and the closed end <NUM> of the aerostructure <NUM>). The coupling <NUM> accommodates mounting of the aerostructure assembly <NUM> to the flight vehicle <NUM>. The coupling <NUM> could be directly mounted to a first component <NUM> of the flight vehicle <NUM>, or could be indirectly mounted to such a first component <NUM> (e.g., via one or more intermediate structures). For instance, one or more fasteners <NUM> could be used for this mounting (e.g., each fastener <NUM> being engaged (e.g., threadably) with at least the coupling <NUM> and the first component <NUM>).

A variation of an aerostructure assembly at least generally in accordance with the foregoing is presented in <FIG> and is identified by reference numeral 50a. Corresponding components between the aerostructure assembly <NUM> and the aerostructure assembly 50a of <FIG> are identified by the same reference numerals. Unless otherwise noted herein to the contrary, the discussion presented above applies to the corresponding components of the aerostructure assembly 50a. The aerostructure assembly 50a is mounted to the flight vehicle <NUM> in the same manner as the aerostructure assembly <NUM> (e.g., via the coupling 100a).

The aerostructure assembly 50a includes an aerostructure 60a having a pair of female receivers (e.g., each being in accord with the female receiver <NUM>), with each such female receiver being interconnected with the outer shell <NUM> by a plurality of supports (e.g., in accord with the first supports <NUM>) to accommodate the coupling assembly 100a having a first beam 120a and a second beam 120b. The beams 120a, 120b are spaced in the third dimension <NUM> and may be disposed in parallel relation to each other. The aerostructure 60a may be attached to the coupling assembly 100a using at least one fastener <NUM> for each of the first beam 120a and the second beam 120b. The first beam 120a and the second beam 120b may be of a common cross-sectional configuration or may utilize different cross-sectional configurations, may be different lengths (as shown in <FIG>) or of a common length, may be of different sizes (as shown in <FIG>) or may be of a common size, or any combination thereof. Each of the beams 120a, 120b may extend from the first end <NUM> of the aerostructure 60a toward, but not to, the closed end <NUM> (as shown in <FIG>) or may extend the entire distance between the first end <NUM> and closed end <NUM> of the aerostructure 60a. It should be appreciated that the coupling assembly 100a could include more than two beams, with the aerostructure 60a then have a corresponding number of female receivers.

A protocol/method for fabricating an aerostructure assembly is presented in <FIG> and is identified by reference numeral <NUM>. An aerostructure is fabricated using a resin pressure molding process (<NUM>). One or more beams of a coupling assembly is directed into an outer shell of the aerostructure, for instance through a corresponding opening on an exterior of the aerostructure (<NUM>). Each such beam may also be directed into a corresponding female receiver of the aerostructure (<NUM>), including where this corresponding female receiver is spaced from the outer shell. Optionally, at least part of a coupling of the coupling assembly may be positioned outside/extend beyond the aerostructure. In any case, the aerostructure may be mounted to the coupling assembly, for instance by directing one or more fasteners through the outer shell of the aerostructure and at least into one or more beams of the coupling assembly (<NUM>).

This present disclosure enables the benefits of RPM structures to be realized for situations where a metallic interface fitting is required. For a control surface this would a smooth aerodynamic outer surface with no fasteners, and a lightweight stiff composite structure. There is potentially a cost benefit to using an out of autoclave process as well.

Any feature of any other various aspects addressed in this disclosure that is intended to be limited to a "singular" context or the like will be clearly set forth herein by terms such as "only," "single," "limited to," or the like. Merely introducing a feature in accordance with commonly accepted antecedent basis practice does not limit the corresponding feature to the singular. Moreover, any failure to use phrases such as "at least one" also does not limit the corresponding feature to the singular. Use of the phrase "at least substantially," "at least generally," or the like in relation to a particular feature encompasses the corresponding characteristic and insubstantial variations thereof (e.g., indicating that a surface is at least substantially or at least generally flat encompasses the surface actually being flat and insubstantial variations thereof). Finally, a reference of a feature in conjunction with the phrase "in one embodiment" does not limit the use of the feature to a single embodiment.

The foregoing description has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present disclosure. " Moreover, where a phrase similar to "at least one of A, B, or C" is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, Band C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.

Claim 1:
An aerostructure assembly (<NUM>; 50a), comprising:
an aerostructure (<NUM>; 60a) comprising an outer shell (<NUM>) having a first end (<NUM>) and a closed end (<NUM>) spaced from the first end along a first dimension (<NUM>), a first female receiver (<NUM>) disposed within an interior of the outer shell (<NUM>) and spaced from the outer shell (<NUM>), and a plurality of first supports (<NUM>) extending between the outer shell (<NUM>) and an outer perimeter of the first female receiver (<NUM>), wherein the aerostructure (<NUM>; 60a) is an integral structure and comprises resin;
a coupling assembly (<NUM>; 100a) comprising a coupling (<NUM>) having a first coupling end (<NUM>) and a second coupling end (<NUM>) that are spaced along the first dimension (<NUM>) and a first beam (<NUM>; 120a), the first beam (<NUM>; 120a) extending from the second coupling end (<NUM>) in the first dimension (<NUM>), into the outer shell (<NUM>) of the aerostructure (<NUM>; 60a), and into the first female receiver (<NUM>) of the aerostructure (<NUM>; 60a); and
at least one first fastener (<NUM>) that extends through the outer shell (<NUM>) and at least into the first beam (<NUM>; 120a).