Mounting systems including load-bearing attachment assemblies and methods for mounting structures to an aircraft

The present disclosure relates generally to aircraft exteriors. More particularly, the present disclosure relates to mounting systems including load-bearing attachment assemblies and methods for mounting structures to an aircraft.

Commercial aircraft may include structures mounted into openings in the aircraft (e.g., openings in an aircraft exterior), such as fuselage-mounted structures. For example, a fuselage-mounted packboard compartment used to stow an inflatable evacuation slide may be mounted into a fuselage opening. Other fuselage-mounted structures include, for example, panels and compartments of various thicknesses used to form the aircraft skin. Such fuselage-mounted structures benefit from being securely mounted using a low weight device, while tending to reduce wear and abrasion of an aircraft mounting surface.

The mounting of fuselage-mounted structures comprised of composite material is particularly challenging because the composite material is susceptible to damage caused by the crushing force of conventional load-bearing fasteners and the ability to fabricate sustainable threads and grooves into the composite material has been elusive. Other conventional methods for mounting the structures to the aircraft exterior including the fuselage have involved adding mass to build the structures themselves, at the expense of additional weight, and then mounting the built structure directly to the aircraft exterior, but such an arrangement undesirably places load bearing forces load directly on the structure itself.

A load-bearing attachment assembly is provided for mounting a structure to an aircraft, according to various embodiments. The load-bearing attachment assembly comprises a male fastening component and a female fastening component. The male fastening component comprises a radially-extending head, a first aperture, and a cylindrical portion extending perpendicular to the radially-extending head. The cylindrical portion has a first threaded portion circumferentially disposed on an outer surface of the cylindrical portion. The radially-extending head comprises a first clamping surface. The female fastening component comprises an annulus enclosing a second aperture, a second clamping surface disposed on the annulus, and a second threaded portion circumferentially disposed on an inner surface perpendicular to the second clamping surface. The first aperture and the second aperture are configured for a fastener to extend therethrough. In response to rotation of the fastener, the first clamping surface translates toward second clamping surface.

A mounting system for mounting a structure to an aircraft is provided, according to various embodiments. The mounting system comprises a male fastening component and a female fastening component. The male fastening component comprises a radially-extending head, a first aperture, and a cylindrical portion extending perpendicular to the radially-extending head. The cylindrical portion has a first threaded portion circumferentially disposed on an outer surface of the cylindrical portion. The radially-extending head comprises a first clamping surface. The female fastening component comprises an annulus enclosing a second aperture, a second clamping surface disposed on the annulus, and a second threaded portion circumferentially disposed on an inner surface perpendicular to the second clamping surface. The female fastening component is configured to be cooperatively engaged with the male fastening component by a fastener that extends through the male fastening component, the female fastening component, and a mounting portion of the structure and into the aircraft where it is secured.

A method for mounting a structure to an aircraft is provided, according to various embodiments. The method comprises inserting, from a first side of a mounting portion of the structure, a first threaded portion of a male fastening component through a mounting opening in the mounting portion. A female fastening component to be cooperatively engaged with the male fastening component is positioned from a second side of the mounting portion. A fastener is passed through respective aligned first and second apertures in the male fastening component and the female fastening component and into the aircraft. The fastener is rotatably tightened to cooperatively engage the male fastening component and the female fastening component to clamp the mounting portion between a first clamping surface of the male fastening component and a second clamping surface of the female fastening component and mount the structure to the aircraft with the female fastening component disposed against the aircraft and provide a load-bearing mounting platform for the structure. The fastener is secured inside the aircraft.

In any of the foregoing embodiments, the first threaded portion is cooperatively engaged with the second threaded portion of the female fastening component. The male fastening component comprises a countersunk threaded screw having the radially-extending head comprising one of a flat head or a domed head, wherein an inboard surface of the radially-extending head comprises the first clamping surface. An outboard side of the annulus comprises the second clamping surface, wherein the first threaded portion of the male fastening component and the second threaded portion of the female fastening component have complementary threads configured for cooperative engagement. The male fastening component is configured to be at least partially positioned on a first side of a mounting portion of the structure and the female fastening component is configured to be at least partially positioned on a second side of the mounting portion. The first clamping surface of the male fastening component and the second clamping surface of the female fastening component are configured for clamping the mounting portion therebetween upon mounting the structure to the aircraft, thereby transferring load to the female fastening component that is disposed against the aircraft. The female fastening component further comprises an annular shoulder extending outboard from the annulus wherein a transition between the annulus and the annular shoulder provides a corner for positioning the second side of the mounting portion into the corner and against the outboard side of the annulus. The mounting portion comprises a substantially flat mounting portion including a mounting opening that extends from the first side to the second side thereof. The first aperture and the second aperture are aligned with the mounting opening and configured for a fastener to extend therethrough from the first side of the mounting portion and into the aircraft where the fastener is secured. The structure comprises at least one of a panel or a compartment. The structure comprises a packboard compartment and the mounting portion comprises a flange portion of the packboard compartment.

The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, the following description and drawings are intended to be exemplary in nature and non-limiting.

The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures.

FIG. 1 is a top view of a load-bearing attachment assembly of a mounting system for mounting a structure to an aircraft, according to various embodiments;

FIG. 2 is a sectional view of a male fastening component and a female fastening component of a load-bearing attachment assembly (in non-engaged condition) taken along the line A-A of FIG. 1 , according to various embodiments;

FIG. 3 is an isolation view of another load-bearing attachment assembly (in a non-engaged condition), according to various embodiments;

FIG. 4 is another view of the load-bearing attachment assembly of FIG. 3 , according to various embodiments;

FIG. 5 is a sectional view of the load-bearing attachment assembly of FIGS. 3 and 4 , illustrating the male fastening component cooperatively engaged with the female fastening component, according to various embodiments;

FIG. 6 is another sectional view of the load-bearing attachment assembly of FIGS. 3 through 5 , illustrating the load-bearing attachment assembly at least partially disposed in a mounting opening in a mounting portion of the structure (a composite panel in the depicted embodiment) and the mounting portion clamped between a first clamping surface of the male fastening component and a second clamping surface of the cooperating female fastening component, according to various embodiments;

FIG. 7 is a perspective view of an exemplary structure (a packboard compartment in the depicted embodiment) configured to be mounted within a fuselage opening using the load-bearing attachment assembly of FIG. 2 or FIGS. 3 through 6 , according to various embodiments;

FIGS. 7A and 7B are enlarged views of an encircled region B on a flange portion (an exemplary mounting portion) of the packboard compartment of FIG. 7 , illustrating engagement of the load-bearing attachment assembly of FIGS. 3 through 6 through the mounting opening of an exemplary pair of mounting openings in the flange portion, according to various embodiments:

FIG. 8A illustrates the packboard compartment of FIG. 7 mounted in a fuselage opening in an aircraft by the load-bearing attachment assembly of FIGS. 3 through 6 and FIG. 8B is an enlarged detailed view of the load-bearing attachment assembly of FIG. 8A , according to various embodiments;

FIG. 9 illustrates a flow diagram of a method for mounting a structure to an aircraft using a load-bearing attachment assembly, according to various embodiments; and

FIG. 10 illustrates another sectional view of a male fastening component and a female fastening component of a load-bearing attachment assembly of FIGS. 1 and 2 according to various embodiments.

The detailed description of various embodiments herein makes reference to the accompanying drawings, which show various embodiments by way of illustration. While these various embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical, chemical, and mechanical changes may be made without departing from the spirit and scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full, and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact.

Various embodiments are directed to mounting systems including a load-bearing attachment assembly and methods for mounting structures to an aircraft using the same. Various embodiments permit the secure mounting of structures having a wide variation in thickness and type of core portion. Various embodiments substantially prevent wear/abrasion of an aircraft mounting surface of the structure. Various embodiments create a lightweight and large surface area load-bearing mounting platform for the mounted structure. As used herein, “aft” refers to the direction associated with the tail (e.g., the back end) of an aircraft, or generally, to the direction of exhaust of the gas turbine. As used herein, “forward” refers to the direction associated with the nose (e.g., the front end) of an aircraft, or generally, to the direction of flight or motion.

Referring to FIGS. 1, 2, and 9 , according to various embodiments, a method 50 for mounting a structure to an aircraft may comprise using a load-bearing attachment assembly 10 a ( FIGS. 1 and 2 ) or 10 b ( FIGS. 3 through 6 ) (step 100 ). Referring specifically to FIG. 2 , according to various embodiments, the load-bearing attachment assembly 10 a comprises a male fastening component 12 a and a cooperating female fastening component 14 a . The male fastening component 12 a and the cooperating female fastening component 14 a each comprise a metallic material. The male fastening component 12 a may comprise a radially-extending head (flange) 18 a , a first aperture 20 a , and a cylindrical portion extending perpendicular to the radially-extending head. The cylindrical portion has a a first threaded portion 15 a comprising a plurality of threads 16 a . The first threaded portion is circumferentially disposed on an outer surface of the cylindrical portion. The radially-extending head 18 a comprises a first clamping surface 33 a . For example, in the depicted embodiment, the male fastening component 12 a is configured as a countersunk threaded screw having a flat head. FIG. 2 illustrates a cross-section of the countersunk threaded screw with a chamfer angle 17 a of 100 degrees, but various chamfer angles may be used. The male fastening component 12 a has the first aperture 20 a defined therein. An inboard surface 22 a of the flat head 18 a of the male fastening component 12 a may comprise the first clamping surface 33 a for purposes as herein described.

Still referring to FIG. 2 , according to various embodiments, the female fastening component 14 a comprises an annulus 13 a , i.e., a circular disk with a center opening 19 a (referred to herein as a “second aperture”). The annulus encloses the second aperture 19 a . A second clamping surface is disposed on the annulus 13 a . The first aperture 20 a of the male fastening component and the second aperture 19 a are configured to be aligned and each has a medial axis A passing through each center. The female fastening component 14 a has an inboard side 24 a configured to be disposed against the aircraft (with momentary reference to FIG. 8A ) and an outboard side 26 a configured to provide a load-bearing mounting platform for the structure. The outboard side 26 a may have a knurled surface 27 a for purposes as herein described. The second aperture 19 a in the female fastening component 14 a includes a second threaded portion including female threads 28 a for cooperative engagement with the male threads 16 a of the male fastening component 12 a . The second threaded portion is circumferentially disposed on an inner surface perpendicular to the second clamping surface. Thus, the male fastening component and the female fastening component have complementary threads for cooperative engagement or attachment with each other as herein described.

Referring again to FIG. 1 and now to FIGS. 3 through 6 , according to various embodiments, a load-bearing attachment assembly 10 b comprises a male fastening component 12 b and a cooperating female fastening component 14 b . The male fastening component 12 b and the cooperating female fastening component 14 b each comprise a metallic material. The male fastening component 12 b may comprise a radially-extending head (flange) 18 b , a first aperture 20 b , and a cylindrical portion extending perpendicular to the radially-extending head. The cylindrical portion has a first threaded portion 15 b comprising a plurality of threads 16 b . The first threaded portion 15 b is circumferentially disposed on an outer surface of the cylindrical portion. The radially-extending head 18 b comprises a first clamping surface 33 b . For example, in the depicted embodiment, the male fastening component 12 b is configured as a countersunk threaded screw having a domed outboard surface 23 b with an inboard surface 22 b of the head 18 b comprising the first clamping surface 33 b in the same manner as the head 18 a of male fastening component 12 a.

Still referring to FIGS. 3 through 6 , according to various embodiments, the female fastening component 14 b comprises an annulus 13 b , i.e., a circular disk with a center opening 19 b (referred to herein as “second aperture 19 b ”). The female fastening component 14 b of load-bearing attachment assembly 10 b further comprises an annular shoulder 21 extending outboard from the annulus 13 b wherein a transition between the annulus 13 b and the annular shoulder 21 provides a corner 30 for positioning a second side 232 of the mounting portion 200 of the structure 202 into the corner 30 and against the outboard side of the annulus. The first aperture 20 b of the male fastening component and the second aperture are configured to be aligned and each has a medial axis A passing through each center. The female fastening component 14 b has an inboard side 24 b configured to be disposed against the aircraft ( FIG. 9 ) and an outboard side 26 b configured to provide a load-bearing mounting platform for the structure. At least a portion of the second aperture 19 b in the female fastening component 14 b includes female threads 28 b for cooperative engagement with the male threads of the male fastening component. While illustrated load-bearing attachment assembly 10 a comprises male fastening component 12 a with a countersunk threaded screw having a radially-extending head (flat head 18 a ) and annulus 13 a and illustrated load-bearing attachment assembly 10 b comprises a countersunk threaded screw with a domed head 18 b and a female fastening component 14 b comprising an annulus 13 b with an annular shoulder 21 , it is to be understood that the countersunk threaded screw having a flat head may be used with a female fastening component having a shoulder and the countersunk threaded screw with a domed head may be used with the annulus without the shoulder. Both annuli 13 a and 13 b may include openings 25 ( FIGS. 2 and 6 ) for use with a tool for tightening the female fastening component around the threaded portion of the male fastening component.

The structure 202 configured to be mounted within an opening (with momentary reference to FIG. 8 ) in the wall of the aircraft (e.g., a fuselage opening) using the load-bearing attachment assembly may comprise the panel (such as panel 202 a shown in FIG. 6 ), a door, a compartment (such as the packboard compartment 202 b of FIGS. 7 through 8 ), or the like. The structure may comprise at least one of a composite material, solid laminate, or the like. Whether made from a composite material, a solid laminate, or another material, the load-bearing attachment assembly 10 a or 10 b according to various embodiments may be used for mounting the structure within the opening to prevent damage to the structure that may otherwise be caused by the crushing force of conventional fasteners. For example, composite material often includes a honeycomb core portion that is relatively soft relative to other portions of the composite material but provides desirable stiffness to the composite material. The honeycomb core portion is particularly susceptible to crushing forces of conventional fasteners. It is also to be understood that fuselage-mounted structures made from materials other than a composite material may benefit from various embodiments.

Referring now specifically to FIG. 7 , according to various embodiments, an exemplary packboard compartment 202 b configured to be mounted within a fuselage opening is depicted. FIG. 8A depicts the fuselage-mounted packboard compartment. The packboard compartment may be mounted within the fuselage opening in the aircraft over a wing such that passengers exiting an emergency exit door would exit onto the wing. An inflatable evacuation slide may be stowed within the packboard compartment. The packboard compartment 202 b depicted in FIGS. 7 and 8 generally comprises a rigid enclosure comprising an inner surface 204 having rear and lateral sides 206 and 208 and an open end 210 configured to be covered by a releasable access panel 212 . The rigid enclosure includes a flange portion as the mounting portion 200 that extends outwardly around the perimeter of the open end 210 of the rigid enclosure. The forward edges of the packboard compartment lateral sides extend upwardly from the packboard compartment second side and are angularly directed toward the packboard compartment second side. The mounting portion 200 (exemplified by flange portion) is substantially flat and includes the first side 232 and an opposing second side 234 with one or more mounting openings 236 extending from the first side 232 to the opposing second side 234 . While FIGS. 7, 7A, and 7B depict only an exemplary number of mounting openings in the flange portion and in encircled region B, it is to be understood that the number of mounting openings 236 may vary from that depicted. The first side 232 of the flange portion (the exemplary mounting portion 200 ) corresponds to a first side of the structure 202 . The first side of the structure (and the flange portion) faces outboard of the aircraft. The opposing second side 234 of the flange portion corresponds to a second side of the structure (and the flange portion). The one or more mounting openings 236 are used for installation of one or more load-bearing attachment assemblies as herein described.

Still referring to FIGS. 7 through 8B and again to FIG. 9 , according to various embodiments, the method 50 for mounting a structure to the aircraft exterior continues by fitting at least a portion of the structure into the opening in the aircraft (for example, a “fuselage opening”) (step 110 ). The structure intrudes into the exterior opening (e.g., the fuselage opening) of the aircraft. The packboard compartment 202 b may be mounted within the fuselage opening with the open end 210 and mounting portion 200 (the flange portion in the depicted embodiment) substantially flush with the exterior or outer surface 240 of the aircraft. The flange portion forms the skin or airflow surface of the aircraft.

Referring now specifically to FIGS. 8A and 8B , one or more “L”-shaped brackets 214 may be mounted in the aircraft, adjacent the opening in the aircraft and inside the aircraft. In accordance with various embodiments, each load-bearing attachment assembly used to mount the structure within the aircraft exterior is held in place by a corresponding “L”-shaped bracket 214 and a fastener 216 such as a threaded attachment screw. The fastener is used to clamp the structure or a portion thereof (such as the mounting portion (exemplified by the flange portion of packboard compartment 202 b ) between the male fastening component and the female fastening component of the load-bearing attachment assembly (more particularly, between the first clamping surface of the male fastening component and the second clamping surface of the female fastening component) and to attach the structure to the aircraft as herein described.

Still referring to FIGS. 8A, 8B, and 9 , according to various embodiments, the method 50 for mounting a structure to an aircraft continues by inserting, from the first side of the mounting portion of the structure, the first threaded portion of the male fastening component through one of the mounting openings in the mounting portion (step 120 ).

Still referring to FIGS. 8A, 8B, and 9 , according to various embodiments, the method 50 for mounting a structure to an aircraft continues by positioning, from a second side of the mounting portion, the female fastening component to be cooperatively engaged with the male fastening component (step 130 ). The first aperture of the male fastening component and the second aperture of the female fastening component are positioned to align with the corresponding mounting opening in the mounting portion of the structure as shown in FIGS. 7A through 8B . In the depicted embodiment, the male fastening component is positioned adjacent a first side of the packboard compartment (more particularly, a first side of the flange portion) in alignment with one of the mounting openings therein. The cooperating female fastening component is positioned adjacent a second side of the flange portion of the packboard compartment in alignment with the male fastening component and the corresponding mounting opening in the flange portion. The male fastening component has the first threaded portion that extends through the mounting opening in the flange portion and is received in the second aperture of the female fastening component at least partially positioned on the second side of the flange portion of the packboard compartment. As the second side of the flange portion is on the inside of the aircraft, the female fastening component, once positioned, is not visible from outside the aircraft. The inboard side of the female fastening component bears directly against the aircraft (more particularly, against the L-shaped bracket inside the aircraft fuselage).

Still referring to FIGS. 8A, 8B, and 9 , according to various embodiments, the method 50 for mounting a structure to an aircraft continues by passing the fastener through the aligned first aperture in the male fastening component and second aperture of the female fastening component, through the mounting opening, and into the aircraft (step 140 ). More particularly, the fastener is passed from outboard the aircraft, through the first aperture of the male fastening component, the second aperture of the female fastening component, through the aircraft exterior wall and through the L-shaped bracket (See FIG. 8B ). FIG. 8B also illustrates that various embodiments may be used to mount a structure having a depth (thickness) that is less than the depth of the opening (e.g., a fuselage opening) in the aircraft, but mounting portion 200 (the flange portion in the depicted embodiment) is substantially flush with the exterior or outer surface 240 of the aircraft. The thickness of the annulus of the female fastening component may be adjusted to compensate for the decreased depth (thickness) of the structure such that the mounting portion may be substantially flush with the exterior or outer surface 240 of the aircraft, yet the weight of the structure has been reduced.

Still referring to FIGS. 8A, 8B, and 9 , according to various embodiments, the method 50 for mounting a structure to an aircraft continues by rotatably tightening the fastener to cooperatively engage the male fastening component and the female fastening component to clamp the mounting portion between the first clamping surface of the male fastening component and the second clamping surface of the female fastening component and mount the structure to the aircraft with the female fastening component disposed against the aircraft and providing a load-bearing mounting platform for the structure (step 150 ). The fastener is secured inside the aircraft by the L-shaped bracket (step 160 ).

According to various embodiments, the two-parts (the male fastening component and the female fastening component) of the load-bearing attachment assembly clamps the mounting portion of the structure from the first side and the second side thereof and also forms a load-bearing mounting platform. As a result, the metallic load-bearing attachment assembly, instead of the fuselage-mounted structure itself, bears the compression load as indicated by multiple arrows L in FIG. 8B .

Referring now specifically to FIG. 10 , according to various embodiments, a load bearing attachment assembly 10 a coupled to a mounting portion 202 as illustrated in FIG. 7 .

While mounting of a packboard compartment has been illustrated, it is to be understood that other structures may be mounted to the aircraft using various embodiments as described herein. For example, a permanent or removable panel may be mounted to the aircraft using various embodiments. Some non-limiting examples include panels and compartments used to form the aircraft skin and exterior and interior access panels that are removed for routine maintenance, or to gain access to portions of the fuselage that need to be opened by the crew.

From the foregoing, it is to be appreciated that the load-bearing attachment assembly according to various embodiments forms a strong, load-bearing and abrasion-resistant mounting platform for the structure permitting the structure to be spaced apart from the aircraft exterior to accommodate structures of varying thickness and type of honeycomb core and reduce wear/abrasion of the aircraft mounting surface. The load-bearing attachment assembly according to various embodiments permits lightweight, secure mounting of structures within the aircraft. Various embodiments substantially prevent damage to the structure and permit a reduction in the overall thickness and mass of the structure configured to be mounted to the aircraft exterior. Various embodiments provide a load-bearing metallic surface at each load-bearing attachment assembly without the need for creating bulky load-bearing features on the structure itself.

Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” 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, B and 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. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials.

Systems, methods and apparatus are provided herein. In the detailed description herein, references to “one embodiment”, “an embodiment” “various embodiments”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant arts) how to implement the disclosure in alternative embodiments.

Furthermore, 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 “comprises”, “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.