Patent ID: 12220877

DETAILED DESCRIPTION

The present disclosure is directed to components that include a plurality of elements joined together and a method for producing the same. Such components may be used in a variety of different applications, including aircraft applications where mechanical strength and light weight are important. Hence, for ease of description the present disclosure will be described in terms of aircraft components but is not limited thereto.

Referring to the FIGURES, an example of a component according to the present disclosure is a relatively thin aircraft component, which may also be referred to as a high-aspect ratio component. Non-limiting types of such aircraft components include control surfaces, winglets, wings, fins, ailerons, canards, elevators, and the like.FIG.1illustrates an aircraft with components of the type that may be produced according to the present disclosure.FIGS.2and3are diagrammatic illustrations of a component20attached to a body21. The component20includes a monolithic structure24and a fitting element26. The monolithic structure24may be described as having a length28, a width30, and a thickness32. The component width30extends between a fitting end34and a distal end36opposite the fitting end34. The monolithic structure24includes a first outer panel38, a second outer panel40, and a plurality of spars42disposed between the first and second outer panels38,40. In some instances, the monolithic structure24may also include structural elements disposed between the panels38,40in addition to the spars42; e.g., ribs (not shown) that extend between spars, etc. The first and second outer panels38,40extend both widthwise and lengthwise. The spars42may be disposed to extend widthwise between the outer panels38,40; e.g., between the distal end36and the fitting end34of the monolithic structure24. In those structures that include ribs, the ribs may be disposed orthogonally relative to the spars42; i.e., in a lengthwise direction.

The widthwise end of each spar42disposed at the fitting end34is configured to mate with a respective blade44of the fitting element26(fitting element26shown in dashed line inFIGS.4and5); e.g., the fitting end of the spar (“spar fitting end46”) is configured as a female portion and the respective blade44is configured as a male portion. The mating spar fitting end46and the fitting element blade44may be referred to as a “joint”. Each spar fitting end46may be generally described as having a Y-shaped configuration with a first finger wall48and a second finger wall50that collectively define a channel52disposed there between. The first finger wall48has a channel side surface54and an exterior surface56. The second finger wall50has a channel side surface58and an exterior surface60. The first and second finger walls48,50diverge from the widthwise extending body62of the spar42and separate from one another to define the channel52disposed there between. Each finger wall48,50may be described as having a divergent end64A,64B (disposed where the respective finger wall48,50diverges from the spar body62) and an opposite distal end66A,66B (disposed at the fitting element26as will be described). The channel52may be described as having a closed end68(adjacent the divergence of the finger walls48,50) and an open end70. The open end70of the channel52is defined at the distal ends66A,66B of the finger walls48,50. In some embodiments, the first and second finger walls48,50may be mirror images of each other; e.g., left and right hand versions. In such embodiments, the first and second finger walls48,50may be opposite in hand but otherwise substantially identical in configuration.

The channel52may assume a variety of different configurations. The geometry of the channel52is typically chosen to have an amount of surface area (i.e., the combined channel side surface area of the first and second finger walls48,50) that is adequate to provide sufficient bonding for the application as will be described below. In the configuration shown inFIG.4, the spar fitting end46has a channel52that includes a parallel channel portion72and a convergent channel portion74. The parallel channel portion72extends between the open end70of the channel52and the convergent channel portion74. The convergent channel portion74extends between the parallel channel portion72and the closed end68of the channel52. In the configuration shown inFIG.5, the spar fitting end46has a channel52with a stepped configuration. The stepped configuration includes a plurality of parallel channel portions76each with a different channel lateral distance78. The parallel channel portion76having the largest channel lateral distance78is contiguous with the open end70of the channel52and the parallel channel portion76having the smallest channel lateral distance78is contiguous with the closed end68of the channel52. The channel52configurations shown inFIGS.4and5are examples provided to illustrate the scope of channel52configurations and therefore the scope of spar fitting end46configurations. The present disclosure is not limited to these examples. A variety of channel52configurations that permit insertion of a mating fitting element blade44may be used. In some embodiments all of the spar fitting ends46have the same configuration. In other embodiments, the configuration of the spar fitting ends46may vary. In this latter configuration, different spar fitting end46configurations may be used to ensure the desired orientation of the monolithic structure24and the fitting element26.

As stated above, the component20(and therefore the monolithic structure24) may be configured for a variety of different applications; e.g., control surfaces, winglets, wings, fins, ailerons, canards, and the like. In many of these applications, the monolithic structure24may comprise a fiber reinforced composite material; e.g., a thermoset fiber reinforced composite material. A specific example of such a composite material is one having a bismaleimide (BMI) matrix reinforced with fibers; e.g., carbon fibers, Kevlar fibers, and the like. The present disclosure is not limited to using any particular composite material. In those embodiments where a monolithic structure24comprises a composite material, the monolithic structure24may be manufactured using a variety of different processes. For example, in some embodiments a monolithic structure24may be initially formed with the first and second outer panels38,40and spar bodies62disposed there between less the spar fitting ends46. In these instances, the monolithic structures24may be formed using a variety of different manufacturing techniques such as, but not limited to, closed mold processes such as resin pressure molding (RPM) or resin transfer molding (RTM), and the like. Subsequently, pre-formed spar fitting ends46may be integrated with the spar bodies62disposed within the initial monolithic structure to complete the monolithic structure24. Alternatively, spar fitting ends46may be formed from composite material plies formed in the desired spar fitting end46configuration and integrated with the respective spar bodies62disposed within the initial monolithic structures to complete the monolithic structure24.

The fitting element26portion of the component20is configured to be joined with the monolithic structure24along the length of the monolithic structure24at the widthwise fitting end of the monolithic structure24. The fitting element26may be configured to attach the component20to an aircraft structure in a fixed manner or in a pivotable manner. The fitting element26may be described as having a body80that includes an edge surface82that extends lengthwise. A plurality of features (each referred to herein as a “blade44”—e.g., seeFIG.7) extend outwardly from the edge surface82. Each of the blades44is configured to form the male portion of the mating connection formed between the fitting element26and the monolithic structure24. The term “blade” as used herein should not be construed as implying any geometric configuration, other than a geometric configuration that mates with a respective spar fitting end channel52. Each fitting element blade44has an exterior surface84having a surface area. To illustrate and referring to the embodiment shown inFIGS.4and7, a fitting element blade44may have a parallel portion86and a convergent portion88. In the diagrammatic view shown inFIG.4, one of the outer panels38,40of the monolithic structure24is removed to provide a view of the spar42and the fitting element blade44(shown in dashed lines). As can be seen, the fitting element blade44and the spar fitting end46channel have mating geometries that closely align; e.g., leaving sufficient room between the channel side surfaces54of channel52and the exterior surfaces84of the blade44for a bond to be created therebetween by an adhesive material or otherwise as will be described below. Now referring toFIG.5, another exemplary fitting element blade44(shown in dashed lines) is shown having a plurality of parallel portions. As stated above, these fitting element blade44configurations are examples, and the present disclosure is not limited thereto. Components20according to the present disclosure have at least one fitting element blade44and therefore at least one mating spar/blade joint. The exact number of mating spar/blade joints may vary depending on the application.

The fitting element26may comprise a variety of different materials. For example, in some applications, a fitting element26that comprises a metallic material (e.g., aluminum, titanium, steel, or alloys thereof, etc.) is desirable. The present disclosure components20are not, however, limited to using metallic fitting elements26, and may alternatively use polymeric fitting elements26, or composite fitting elements26, or the like, or any combination thereof.

In some component20embodiments, one or both of the outer panels38,40of the monolithic structure24may include widthwise extending portions90that extend widthwise beyond the spars42for attachment to the fitting element26.FIG.3, for example, shows both the first and second outer panels38,40having widthwise extension portions90that extend beyond the mating spar/blade joints. Mechanical fasteners92may be used to connect these widthwise extension portions90to the fitting element26.

In some embodiments, the spar fitting end46and fitting element blade44are attached to one another by an adhesive agent that creates a bond between at least some, and preferably most, of the channel side surfaces54,58of the channel52and the exterior surfaces84of the blade44. An adhesive material that produces an acceptable bond characteristics (e.g., strength, useful life, etc.) for component20operating conditions (e.g., forces applied, temperature, environmental conditions, etc.) and spar/fitting element materials (e.g., composite/metallic, or composite/composite, etc.) is used. The present disclosure is not limited to any particular adhesive material.

Each mating spar/blade joint is configured to withstand at least a portion of the loading (e.g., bending loads, shear loads, etc.) associated with the component20application. For example, the contiguous surface areas of the channel side surfaces54,58of the channel and the exterior surfaces84of the blade44are typically sized to produce a bond interface that can withstand a portion of the loading associated with the component20application. Larger loading applications can be accommodated by increasing the joined surfaces areas and/or the mating configuration, and/or increasing the number of spars42. In those embodiments wherein the attachment between the fitting element26and the monolithic structure24is limited to the mating spar/blade joints, the aforesaid mating spar/blade joints collectively withstand the loading associated with the component20application. In those embodiments wherein the attachment between the fitting element26and the monolithic structure24includes the mating spar/blade joints and mechanical fasteners92attaching widthwise extending portions90of the outer panels38,40to the fitting element26, the loading associated with the component20application may be accommodated by both the mechanical fastener attachment and the bonded mating spar/blade joints.

An example of a present disclosure method for forming a component20as described above includes forming an initial monolithic structure24with the first and second outer panels38,40and spar bodies62disposed there between less the fitting ends46. In that case, preformed spar fitting ends46may be subsequently integrated with the spar bodies62disposed within the initial monolithic structure24, or the integration process may include forming spar fitting ends46in the desired spar fitting end46configuration using composite material plies. As stated above, a monolithic structure24may be formed from a fiber reinforced composite material such as a carbon fiber reinforced BMI composite. The forming process may include using a closed mold process such as a resin pressure molding (RPM) process. A complete monolithic structure24(i.e., including the spar fitting ends46) produced in this manner provides a lightweight, strong, durable, and inexpensive alternative to a similar structure formed from a metallic material.

The present method may further include producing a fitting element26having a body80with a lengthwise extending edge surface82that includes one or more blades44extending outwardly from the edge surface82. Each of the aforesaid blades44is configured to have a geometry that mates with the channel52of a respective spar fitting end46; i.e., to form the male portion of the mating connection formed between the fitting element26and the monolithic structure24. As stated above, the fitting element26may be formed from a metallic material such as aluminum, titanium, steel, or the like, or alternatively a composite material.

An adhesive agent operable to create a bond between one or more channel side surfaces54,58of the channel52and one or more blade44exterior surfaces84may be applied to at least one or more channel side surface54,58and/or at least one blade44exterior surface84. In some embodiments, the adhesive agent is applied all of the channel side surfaces54,58of the respective fitting end channel52and/or all of the exterior surfaces84of the respective blade44. Once the monolithic structure and the fitting element26are in form for joinder, the two elements24,26are brought together with each blade44received within an aligned spar fitting end channel52. At this point, the “joint” between the respective blade44and the spar fitting end channel52are internal to the component20and are inaccessible from the exterior of the component20; i.e., the joints are “blind”. The steps necessary to produce the desired bonding between the now coupled elements24,26may vary depending on the particular adhesive agent used. For example, some adhesive agents are configured to cure under predetermined environmental conditions; e.g., pressure, elevated temperature, etc. The present disclosure is not limited to any particular bonding process.

In embodiments wherein the monolithic structure24and the fitting element26are both comprised of polymeric material(s), the bonding there between may be produced by resin transfer and/or resin bonding between the two elements24,26at the various interfaces. In these instances, the need for an adhesive agent may be obviated.

In those embodiments wherein one or both of the outer panels of the monolithic structure24include widthwise extending portions90that extend widthwise beyond the spars42, the aforesaid widthwise extension portions90may be attached to the fitting element26via mechanical fasteners92or by other means.

As is described above, the present disclosure provides a novel and unobvious lightweight, strong, durable, and inexpensive component20that does not require mechanical fasteners. High aspect ratio components20very often have a thickness that makes it difficult or impossible to use mechanical fasteners to combine component elements. In fact, these type components often have elements that are internally located and therefore inaccessible for such attachment procedures. Still further, attachment schemes that pass through the outer panels are often undesirable. The present disclosure provides a solution that avoids the need for mechanical fasteners internally within the component20or attachment schemes that require fasteners extending through component20outer panels and provides an attachment that can be configured to provide the requisite attachment integrity in a cost effective way. This is particularly true for components that include a metallic fitting element26and a composite monolithic structure24.

While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure. Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details.

It is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a block diagram, etc. Although any one of these structures may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.

The singular forms “a,” “an,” and “the” refer to one or more than one, unless the context clearly dictates otherwise. For example, the term “comprising a specimen” includes single or plural specimens and is considered equivalent to the phrase “comprising at least one specimen.” The term “or” refers to a single element of stated alternative elements or a combination of two or more elements unless the context clearly indicates otherwise. As used herein, “comprises” means “includes.” Thus, “comprising A or B,” means “including A or B, or A and B,” without excluding additional elements.

It is noted that various connections are set forth between elements in the present description and drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. Any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option.

No element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprise”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

While various inventive aspects, concepts and features of the disclosures may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts, and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present application. Still further, while various alternative embodiments as to the various aspects, concepts, and features of the disclosures—such as alternative materials, structures, configurations, methods, devices, and components, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts, or features into additional embodiments and uses within the scope of the present application even if such embodiments are not expressly disclosed herein. For example, in the exemplary embodiments described above within the Detailed Description portion of the present specification, elements may be described as individual units and shown as independent of one another to facilitate the description. In alternative embodiments, such elements may be configured as combined elements.