Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02745554 2011-07-07
CARGO AIRCRAFT SYSTEM
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Patent Application, Serial No.
12/833,868 filed on July 9, 2010.
FIELD OF THE INVENTION
[0002] The present invention relates to a cargo aircraft system and, more
particularly, to a cargo aircraft system that is designed to transport modular
cargo units
of various configurations and sizes.
BACKGROUND
[0003] The basic unit for transporting goods has been the truck. Being the
basic
unit, the truck has defined limitations on intermodal containers that can
typically be
transported by ships, trains and trucks. However, airplanes have generally
been
excluded from participation in intermodal and many other types of cargo. This
is due to
the limitations placed by the design and construction of cargo airplanes.
[0004] The design and construction of most civilian cargo aircraft are based
on
that of passenger airplanes. The basic structure is a monocoque-based fuselage
which
is substantially cylindrical in shape. Monocoque-based structures support the
structural
load of an aircraft by a unitary structural body, as opposed to heavier
internal frames or
trusses. The unibody construction of the monocoque-based aircraft generally
lack
sufficient structure to adequately or efficiently support and distribute
concentrated cargo
loads across the aircraft fuselage and to the wings.
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[0005] Additionally, the cylindrically-shaped fuselage imposes additional
restrictions on cargo size and dimensions. Thus, cargo having irregular or
unusually
large dimensions are generally unsuited for air transport via today's cargo
aircraft.
Moreover, as most cargo units are substantially rectangular in shape, loading
such
cargo units into a cylindrical fuselage results in a significant amount of
wasted dead
space.
SUMMARY
[0006] The cargo aircraft systems disclosed herein comprise a spine structure
onto which a cargo assembly may be mounted. The spine structure replaces the
cylindrically-shaped monocoque-based fuselages of today's aircraft and has
sufficient
structure, in combination with the cargo assembly, to distribute concentrated
cargo
loads along its length and to the wings. The cargo assembly is an integrated
and
unitary structure formed from one or a plurality of cargo units coupled
together. The
cargo unit may be a modular frame unit or a modular container unit and the
resulting
cargo assembly may be any one or a combination of modular frame and container
units.
The cargo assembly is structurally integrated with the spine to form part of
the aircraft
structure such that the aircraft is able to withstand tortional and bending
loads
experienced during flight. Thus, the cargo assembly augments the structure of
the
spine, which itself would not be able to sustain the tortional and bending
loads of the
aircraft when the spine is loaded with the cargo assembly. Moreover, because
the
cargo aircraft eliminates the need for additional structure to support the
load of the
cargo assembly, a significant reduction in the weight of the cargo aircraft is
realized.
This, in turn, results in greater fuel efficiency and decreased cost of
operation.
[0007] In one embodiment, a cargo assembly is provided. The cargo assembly is
configured to be structurally integrated to a spine of an aircraft. The cargo
assembly
comprises a plurality of modular cargo units, a first load transfer system and
a second
load transfer system. The first load transfer system comprises a plurality of
first
attachments to removably couple adjacent modular cargo units. The second load
transfer system comprises a plurality of second attachments to removably mount
and
1)
CA 02745554 2011-07-07
structurally integrate the cargo assembly to the spine of the aircraft. The
first and
second load transfer systems distribute the aerodynamic load of the aircraft
in flight
between the plurality of modular cargo units and the spine of the aircraft.
[0008] In accordance with a first aspect, the plurality of modular cargo units
comprises one or more structural frames having defined spaces to accommodate
cargo.
[0009] In accordance with a second aspect, the plurality of modular cargo
units
comprises one or more containers.
[0010] In accordance with a third aspect, the cargo assembly comprises a
combination of one or more structural frames and one or more containers.
[0011] In accordance with a fourth aspect, the first load transfer system
further
comprises a plurality of interconnecting hinge assemblies associated with at
least two of
the plurality of modular cargo units.
[0012] In accordance with a fifth aspect, the first load transfer system
further
comprises one or more splices to couple adjacent modular cargo units.
[0013] In accordance with a sixth aspect, the one or more splices are disposed
on an opposing side of the cargo assembly to a mounted side of the cargo
assembly.
[0014) In accordance with a seventh aspect, the first load transfer system
further
comprises a tensioning system disposed within at least one of the modular
cargo units.
[0015] In another embodiment, a cargo assembly is provided. The cargo
assembly is configured to be structurally integrated to a spine of an
aircraft. The cargo
assembly comprises a plurality of modular cargo units, first attachments and
second
attachments. The first attachments are configured to structurally couple and
integrate
the plurality of cargo units into a single assembly. The second attachments
are
configured to structurally integrate the single assembly with the aircraft
spine. The
plurality of cargo units are arranged within the single assembly based on a
weight of
each one of the respective cargo units to obtain a center of gravity of the
aircraft and the
cargo assembly attached thereon within a range acceptable for flight.
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[0016] In accordance with a first aspect, the modular cargo units are
comprised
of any one or a combination of structural frames and/or containers.
[0017] In accordance with a second aspect, the cargo units are each
constructed
to support a range of maximum cargo loads.
[0018] In accordance with a third aspect, the cargo units having the highest
maximum cargo loads are arranged at or near the center of gravity of the
unloaded
aircraft.
[0019] In a further embodiment, an aircraft for transporting a plurality of
cargo
containers is provided. The aircraft comprises a forward fairing, an
empennage, and a
spine disposed between the forward fairing and the empennage. A cargo assembly
is
configured to be detachably integrated with the spine. The spine has a
lightweight
structure such that the aircraft has sufficient rigidity to withstand bending
and tortional
loads in flight when unloaded with the cargo assembly. The spine, however, has
insufficient rigidity to itself withstand bending and tortional loads in
flight when loaded
with the cargo assembly. The cargo assembly provides the additional rigidity
to the
spine required for the aircraft to fully withstand bending and tortional loads
in flight when
the cargo assembly is structurally integrated with the spine.
[0020] In accordance with a first aspect, the modular cargo units are
comprised
of any one or a combination of modular structural frames and cargo containers.
[0021] In accordance with a second aspect, the aircraft further comprises one
or
more trusses coupling the cargo assembly to the spine.
[0022] In accordance with a third aspect, the aircraft further comprises
fairings to
enclose the cargo assembly mounted on the spine.
[0023] In accordance with a fourth aspect, the aircraft further comprises
mounts
to detachably engage and structurally couple the cargo assembly to the spine.
[0024] In accordance with a fifth aspect, the mounts are disposed on the
underside of the spine to detachably suspend the cargo assembly therefrom.
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[0025] In accordance with a sixth aspect, the mounts are actuated between a
first
and second position, wherein in the first position, the mounts structurally
engage the
cargo assembly to the spine and wherein in the second position, the mounts
disengage
and therefore release the cargo assembly from the spine.
[0026] In accordance with a seventh aspect, a control is provided to
alternately
actuate the mounts between the first and second positions.
[0027] Other objects, features and advantages of the present invention will
become apparent to those skilled in the art from the following detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Illustrative embodiments of the present invention are described herein
with
reference to the accompanying drawings, in which:
[0029) FIG. 1 is an exploded perspective view of an embodiment of a cargo
aircraft system in which the aircraft has a lower spine.
[0030] FIG. 2 is a simplified elevation view of a single-layer cargo assembly
mounted on a spine.
[0031] FIG. 3 is a perspective view of an embodiment of a support truss.
[0032) FIG. 4A is cross-sectional view taken transversely through a lower
aircraft
spine section.
[0033] FIG. 4B is a cut-out cross-sectional view taken transversely of a lower
aircraft spine section.
[0034] FIG. 4C is an exploded perspective showing components of a lower
aircraft spine section.
[0035] FIG. 5 is an exploded perspective view of another embodiment of a cargo
aircraft system in which the aircraft has an upper spine.
[0036] FIG. 6A is cross-sectional view taken transversely through an upper
aircraft spine section
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[0037] FIG. 6B is a cut-out cross-sectional view taken transversely of an
upper
aircraft spine section.
[0038] FIG. 6C is an exploded perspective showing components of an upper
aircraft spine section.
[0039] FIGS. 7A-7C are perspective views of an embodiment of modular frame
units configured to be coupled together to form a structural frame assembly.
[0040] FIGS. 8A-8B are perspective views of an embodiment of modular
container units configured to be coupled together to form a structural
container
assembly.
[0041] FIG. 9 is a cross-sectional view of an embodiment of a mount coupling a
cargo container to a spine.
[0042] FIG. 10 is an exploded perspective view of a pair of corner attachments
and a coupler.
[0043) FIG. 11 is a perspective view of a modular cargo container comprising
multiple points of attachment to the spine.
[0044] FIGS. 12A-12B are perspective views of modular frame units and modular
container units coupled together in different configurations.
[0045] FIGS. 13A-13B are perspective views of modular container units
featuring
interconnecting hinge assemblies.
[0046] FIGS. 14A-14D depict tensioning systems that may be used in connection
with the modular frame and container units.
[0047] FIGS. 15A-15B depict a splicing system coupled to a cargo assembly to
provide additional structural support.
[0048] Like numerals refer to like parts throughout the several views of the
drawings.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] FIG. 1 illustrates an embodiment of a cargo aircraft system 100. The
cargo aircraft system 100 is depicted as comprising an aircraft 110 and a
cargo
assembly 105 comprised of modular cargo containers of various dimensions and
sizes.
Embodiments of the basic structure of a cargo aircraft are also described in
U.S. Pat.
No. 7,261,257, issued August 28, 2007, the entire contents of which are
incorporated
herein by reference.
[0050] Generally, the cargo aircraft 110 comprises a forward fairing 112, an
empennage 130 and a lower spine 120 between the forward fairing 112 and
empennage 130. The lower spine 120 comprises guide flanges 124 which run
longitudinally along each side of the spine 120 to guide the cargo assembly
105 in place
during loading on the lower spine 120. A plurality of mounts 122 is disposed
at various
intervals along the lower spine 120 to structurally engage the cargo assembly
105 at
various attachment points onto the lower spine 120.
[0051] Wings 140 are structurally associated with the lower spine 120. Wings
140 may optionally contain fuel tanks (not shown). Landing gear 150A may be
provided
under the wings 140 and or lower spine 120 and a forward gear 150B may be
provided
under the lower spine 120 or the forward fairing 112. Alternatively, the
landing gear
may have their own fairings or pods. Engines 142 are shown in the embodiment
of FIG.
1 to be mounted on top of the wings 140. It is understood that the engines 142
may
also be mounted under the wings 140 and/or on the spine 120. Aerodynamic
fairings
180, 190 may be optionally provided to enclose the cargo assembly 105 and the
trusses
160, 170. The aerodynamic fairings 180, 190 are made of a composite light
weight
material and the primary function of the aerodynamic fairings is to reduce
drag. In a
particularly preferred embodiment, the aerodynamic fairings do not provide
substantial,
if any, support or rigidity to the aircraft in flight.
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[0052] Trusses 160, 170 further engage the cargo assembly 105 to the lower
spine 120. Trusses 160, 170 provide additional structural support to the
aircraft to
withstand bending moments in flight and provide further support and
integration of the
cargo assembly 105 onto the lower spine 120. Depending on the direction from
which
the cargo assembly is loaded onto the spine, either one or both of the forward
truss 160
and the rear truss 170 may be removably attached to the spine 120. Thus, for
example,
in an embodiment where the cargo assembly is loaded through the empennage 130
of
the aircraft 110, the rear truss 170 would be removed from the spine 120 prior
to
loading.
[0053] FIG. 2 depicts the points of attachments at which the bending moments
may be transferred between the cargo assembly 105 and the lower spine 120. It
is
understood that while FIG. 2 depicts cargo assembly comprising only a single
layer of
modular container units, cargo assemblies comprising multiple layers modular
container
or frame units may also be accommodated by modifying the truss 168, 178 to
include
additional points of attachment for each layer.
[0054] FIG. 3 depicts an exemplary rear truss 170 that may be used to couple
cargo assemblies comprising two layers of modular containers or frame units.
The truss
170 comprises horizontal support members 172 fixed to vertical support members
174
at a 90 degree angle. Two sets of diagonal support members 171 A, 171B couple
the
horizontal support members 172 and the vertical support members 174 at
different
points corresponding roughly to the heights of the first and second layers of
the cargo
assembly 105. Stabilizer bars 173A, 173B are optionally provided along the
points
where the diagonal support members 171A, 171B are joined to the vertical
support
members 174. Mounts 176 are provided along the stabilizer bars 173A, 173B to
securely fasten the cargo assembly to the truss 170. The forward truss 160 is
understood to be constructed in a manner similar to the rear truss 170, with
the
exception that the forward truss 160 may be permanently affixed to the spine
120,
whereas the rear truss 170 may be a removable structure in embodiments where
the
cargo assembly 105 is loaded through the empennage 130 of the aircraft 110.
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[00551 FIGS. 4A-C show the structure of the lower spine 120 of the cargo
aircraft
110 in greater detail. The structural support of the lower spine 120 comprises
layers of
interconnected bulkheads 128 and spars 126. The bulkheads 128 and spars 126
may
be interconnected by means known in the art such as, for example, by bolting,
riveting,
welding, friction stir welding, or bonding. While the lower spine 120 depicted
in FIGS.
4A-C show two layers of interconnected bulkheads 128 and spars 126, it is
understood
that a lighter weight spine 120 comprising only a single layer of
interconnected
bulkheads 128 and spars 126 may be provided for lighter cargo assembly weight
loads.
Alternatively, additional layers of interconnected bulkheads 128 and spars 126
may be
provided to accommodate cargo assemblies having higher weight loads.
[0056] The layers of interconnected bulkheads 128 and spars 126 may be
enclosed by a spine surface 125 and an aerodynamic fairing or skin 121 to form
a
torque box. The spine surface 125, upon which the cargo assembly is mounted,
may
comprise a pair of guide flanges 124 disposed longitudinally along the spine
120. The
spine surface 125 may further comprise openings 127 to expose the mounts 122
coupled to the interconnected bulkheads 128 and spars 126. The exposed mounts
122
provide a point of attachment for the cargo assembly 105. In a preferred
embodiment,
the mounts 122 are designed to retract below the spine surface 125 to allow
the
container assembly to slide across the spine. The embodiment of the spine 120
shown
in FIG. 4A-C is especially suited for cargo assemblies 105 which comprise two
layers of
stacked cargo units, as it comprises two layers of interconnected bulkheads
128 and
spars 126.
[0057] FIG. 5 illustrates another exemplary embodiment of the cargo aircraft
system 200 comprising a cargo aircraft 210 and a cargo assembly 205. Unlike
the
cargo aircraft of FIG. 1, an upper spine 220 connects the forward fairing 212
and the
empennage 230. Thus, the cargo assembly 205 is suspended from the underside of
the upper spine 220. In accordance with one embodiment, in which the empennage
is
comprised of two halves pivotally attached to the spine, the rear truss
structure 270 may
also be constructed in two pieces such that when the empennage opens to allow
entry
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of the cargo assembly for loading, the rear truss structure 270 may similarly
be opened
with the empennage to expose the spine 220 for loading. Alternatively, in
embodiments
where the entire empennage is pivotally attached to the spine, the entire rear
truss
structure 270 may also be coupled to the empennage and similarly rotated away
from
the spine to expose the spine for loading from the rear. It is understood that
these
embodiments may also be implemented with the lower spine aircraft depicted in
FIG. 1.
[0058] Wings 240 are structurally associated with the upper spine 220 and may
also contain fuel tanks (not shown). The upper spine 220 may also carry fuel.
The
upper spine 220 further comprises guide flanges 224 which run longitudinally
along the
underside surface of the upper spine 220. A plurality of mounts 222 are
provided
throughout the underside of the lower spine 220 and are configured to secure
and
integrate the cargo assembly 205 with the upper spine 220. Although FIG. 5
depicts the
engines 242 as being mounted on top of the wings 240, it is understood that
the
engines 242 may also be mounted under the wings 240 or even on the upper spine
220
or a combination thereof. Aerodynamic fairings 280, 290 may be optionally
provided to
enclose the cargo assembly 205 and the trusses 260, 270. The aerodynamic
fairings
280 may further comprise a plurality of opening panels 282 to expose portions
of the
cargo assembly 205. Again, in a particularly preferred embodiments, the
aerodynamic
fairings are made as lightweight as possible and do not contribute
significant, if any,
structural support to the aircraft.
[0059] FIGS. 6A-C show the structure of the upper spine 220 in greater detail.
Upper spine 220 comprises a layer of interconnected spars 126 and
bulkheads/ribs 228,
238 to which mounts 222 are attached. A surface 226 having a plurality of
openings
227 is provided to expose the mounts 222. In contrast to the lower spine 120
of FIGS.
4A-C, the upper spine 220 of FIGS. 6A-G comprise only a single layer of
structural
support to support a cargo assembly comprising a single row of containers. It
is
understood that additional layers of interconnected spars 226 and
bulkheads/ribs 228,
238 may be provided as required by higher weight regimes.
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[0060] The spine structure depicted in FIGS. 1-2 and 4-6 are designed to be as
light as possible. As such, the spine structure is capable of supporting
takeoff loads,
flight loads and landing loads of the aircraft when free of cargo. However,
when the
cargo assembly is mounted on the spine, the spine, by itself, is not required
to fully
sustain bending and tortional loads in flight, and landing and takeoff loads.
The
additional rigidity required is supplied by the cargo assembly. The cargo
assembly
augments the spine and aircraft structure so as to support these loads when it
is
structurally integrated to the spine. To this end, the individual units
comprising the
cargo assembly are constructed with sufficient structure and rigidity and are
securely
mounted to the spine such that bending and tortional forces experienced by the
spine
structure are imposed upon the cargo assembly.
[0061] The simplicity of the spine structure furthermore permits it to be
configured
in any variety of widths and weight capacities. Thus, for example, the spine
may be
configured to support extra large cargo loads which cannot be transported
within
standard intermodal containers by simply increasing the width and the number
of layers
of interconnected bulkheads and spars to an extent necessary to accommodate
such
extra large cargo loads. Thus, the spine permits greater flexibility with
respect to the
dimensions of the cargo assembly than would be realized by an aircraft with
the
standard monocoque-based cylindrical fuselage. Moreover, the structural
features of
the spine allow for the cargo load to be more efficiently distributed along
the spine and
also to the wings.
[0062] Thus, the cargo assembly is integrated as part of the structure of the
aircraft such that it provides the rigidity required to fully sustain the
bending and tortional
loads exerted on the aircraft in flight. The cargo assembly may be comprised
of
structural frame assemblies or structural container assemblies. The structural
frame
assemblies, in turn, may be comprised of modular frame units of varying
dimensions,
sizes and weight capacities. Similarly, the structural container assemblies
may be
comprised of modular container units, also having varying dimensions, sizes
and weight
capacity as dictated by the needs of the cargo being transported.
it
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[0063] The cargo assembly may be constructed as comprising structural frame
assemblies, structural container assemblies, or combinations thereof. The
modular
nature of the containers and frames allows great flexibility in creating a
final cargo
assembly that is capable of accommodating various types, sizes, dimensions and
weights of cargo. Once these modular units are structurally coupled together
to form a
cargo assembly, they may be coupled to the aircraft spine to provide an
integrated
structure that is capable of taking on and distributing bending and tortional
loads to the
spine and the wings of the aircraft.
[0064] FIGS. 7A-C depict exemplary embodiments of modular structural frame
units 300 which may be used to accommodate units of cargo of varying
dimensions.
Each of the modular structural frame units 300 depicted in FIGS. 7A-C are
configured to
be coupled with one another to create a larger integrated structural frame
assembly. It
is understood that the greater the number of attachments between modular frame
units
300, the more efficiently load is transferred and distributed among the
modular frame
units 300. In one exemplary embodiment, frame units 300 are structurally
attached to
one another by couplers (see FIG. 10) which attach facing end attachments 312
and
corner attachments 314 of the adjacent structural frame assemblies.
[0065] As shown in FIGS. 7A-B, the modular frame units 300 comprise a
plurality
of vertical frame members 316 and horizontal frame members 318 which are
coupled
together to form a parallelepiped shaped structure. The modular frame units
300
include a plurality of defined spaces 310A-D which may accommodate units of
cargo
305A-D, respectively. While the plurality of defined spaces 310A-D in FIGS. 7A-
B are
depicted as rectangular shaped spaces to accommodate rectangular shaped cargo
units, it is understood that the modular frame units 300 may be configured to
accommodate cargo units of other shapes and sizes.
[0066] The modular frame units 300 may further comprise means by which
individual cargo units 305A-D may be secured onto the defined spaces 310A-D.
As
shown in FIG. 7A, brackets 320 may be coupled to opposing horizontal frame
members
318 to allow the cargo units 305A-D to be slidably inserted into the
respective defined
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spaces 310A-D. Alternatively, a tongue-in-groove fitting may be provided, as
shown in
FIG. 7B, in which frame unit 300 includes a plurality of tongue fittings 330
along the
horizontal frame member 318 and the cargo units 305A-D each comprise
corresponding
groove fittings 340 to slidably engage the tongue fittings 330 disposed in the
defined
spaces 310A-D. While FIG. 7B shows the frame assembly 310 as comprising the
tongue fittings 330 and the cargo units 305A-D as comprising the groove
fittings 340, it
is understood that the tongue fittings 330 and groove fittings 340 may be
provided on
either one or a combination of the frame assembly 310 and the cargo units 305A-
D.
[0067] FIG. 7C shows another embodiment of the structural frame assembly 311
which comprise two structural frames 311A and 311B which are coupled together
at
facing corner attachments 312 and side attachments 314 of adjacent frame
assemblies
via couplers (see FIG. 10). The structural frames 311A, 311B depicted herein
provide
eight defined spaces 313A-H which may accommodate cargo units 305A-H,
respectively. While not shown in FIG. 7C, it is understood that the frame
assembly 311
of FIG. 7C may employ the same means (e.g., brackets, tongue and groove
fittings,
etc.) depicted in FIGS. 7A-B to secure the individual cargo units 305A-H
within the
respective defined spaces 313A-H in the structural frame assembly 311.
[0068] An integrated structural frame assembly may be created by structurally
attaching the modular frame units depicted in FIGS. 7A-C by means of the
corner
attachments 312 and side attachments 314. This integrated structural frame
assembly
may be of sufficient strength and rigidity to support the cargo units and the
aerodynamic
load, including the bending and tortional loads of the cargo aircraft in
flight.
[0069] In preferred embodiments, the integrated structural frame assembly is
constructed of lightweight materials which have sufficient strength and
rigidity to at least
support a cargo unit up to a defined weight. Exemplary materials include
lightweight
metals or allows thereof, such as aluminum and titanium and steel or a
combination of
metal and composite structures or even innovative layers of different metals
and lattice
structures. Other exemplary materials include composites such as carbon epoxy
laminates, as well as foam core and honeycomb core structures.
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[00701 In other preferred embodiments, the individual cargo units are provided
in
containers which are also configured to provide additional structure to
support the load
of the aircraft in flight. This may be accomplished by effectuating a
structural
attachment between the cargo units and the frame assemblies (as shown in FIG.
7B).
Thus, in these other preferred embodiments, both it is the combination of the
integrated
frame structure and the individual cargo units that provides the strength and
rigidity to
support the aircraft in flight.
[00711 FIGS. 8A-B show modular container units which may also comprise the
cargo assembly that is mated onto the aircraft spine. In contrast to the
modular frame
units, modular container units provide an enclosed space within which cargo
units may
be placed. Similar to the modular frame units, the modular container units
provide the
structure and rigidity to the final assembled cargo assembly which, in turn,
provides this
rigidity to the spine to support the aircraft in flight. The modular container
units are each
structurally attached to one another so as to distribute the aerodynamic load
between
them. Thus, the individual cargo containers are preferably constructed from
rigid
materials which are capable of withstanding and distributing bending,
tortional,
compression and tension loads of the loaded aircraft during flight. Exemplary
materials
include lightweight metals or allows thereof, such as aluminum and titanium
and steel or
a combination of metal and composite structures or even innovative layers of
different
metals and lattice structures or a combination of metal and composite
structures. Other
exemplary materials include composites, such as carbon epoxy laminates, as
well as
foam core and honeycomb core structures.
[0072] FIGS. 8A-B show modular container units of various sizes are configured
to structurally mate with one another to create a cargo assembly. In FIG. 8A,
the
modular container units 405A may be aggregated and structurally attached to
one
another via corner attachments 412 to create a larger structural container
assembly
400A. This larger container assembly 400A may be further joined to other
container
assemblies or structural frame assemblies to create an integrated cargo
assembly that
may be mounted onto the aircraft spine. In FIG. 8B depicts the modular
container units
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405B are rectangular in shape and may be aggregated and structurally attached
to one
another via both corner attachments 412 and side attachments 414.
[0073] Both the structural frame assemblies and the structural container
assemblies may be attached to the spine via mounts. FIG. 9 shows an exemplary
embodiment of a mount 123 that may be provided on the spine structure 120.
While
FIG. 9 shows the mount 123 as connecting a container 105 with the spine
structure 120,
it is understood that the mount 123 may also be used to connect adjacent
containers
together to form the cargo assembly.
[0074] Mounts such as the one depicted in FIG. 9 may be bolted or otherwise
retained on the spine 120. Further, incremental adjustments are preferably
provided in
order that the mounts 123 may attach to the container or containers 105 while
accommodating variations in container length and placement. Such incremental
adjustment may be provided by patterns of attachment holes in the spine 120 to
allow
for lateral or longitudinal repositioning of the mounts 123 once the container
or
containers 105 are in place. A mount 123 is illustrated in FIG. 9 as a
shoulder bolt 123
which extends between the spine structure 120 and a container 105. Such a bolt
123
provides substantial shear resistance as well as tension loading. The mounts
123 may
be located or positionable along the full length of the spine 120 or at
incremental
positions reflecting standard container sizes. The mounts 123 may face
inwardly from
the sides of the spine 120. Access ports through the fairings may be provided
to allow
access to the mounts 123 or sufficient space may be provided between the
aerodynamic fairing and the container assembly sidewall to allow personnel to
inspect
as well as attach the containers to the spine without having access panels
through the
side fairings. In yet an alternative embodiment, mechanisms may be employed to
remotely actuate the mounts to engage and disengage the containers.
[0075] FIG. 10 further illustrates the attachments that may be used to couple
adjacent structural frames and containers. Corner attachments 74 comprise
formed
boxes 76 through which slots 78 extend. By employing the formed boxes 76, the
slots
78 terminate to provide an inner face. The attachments 74 cooperate with the
formed
CA 02745554 2011-07-07
boxes 74 with slots 76 through the walls thereof. The formed boxes 76 may
include
thick walls on one outer side or bottom to receive the mounts 123. To fix the
attachments 74 to one another, couplers 84 are employed. Each coupler 84
includes
two heads 86 extending in opposite directions from a coupler body 88. The
heads 86
are undercut between the body 88 and each of the heads 86 to form opposed
engaging
surfaces on the inner sides of the heads 86. The heads 86 also fit within the
slots 76 in
one orientation. The heads 86 have a convex surface for easier placement in
the
associated slots 76. Once rotated, the head provides good tension loading.
These
types of connections currently exist in the Intermodal system environment and
can take
shear as well as tension loads.
[0076] The couplers 84 may be formed such that the heads 86 are on a shaft
rotatable within the body 88. A collar 90 is separated from each of the heads
86 by
substantially the thickness of the walls of the formed boxes 76 with the
collar 90 being
of sufficient diameter that the collar 90 cannot fit within the slots 78. The
collar 90 also
provides access once the heads 86 are positioned in the slots 78 for rotation
of the
heads 86 into a locked orientation with the slots 78. The body 88 is of
sufficient size
and includes flat sides 92 such that it is prevented from rotating by the
floor 32. Once
the head 86 have been properly located, a rotation handle 94 that will allow
rotation of
the head 86 into the locking position and remain in that position during
flight. The same
mechanisms are employed between attachments 74 on adjacent containers 70.
[0077] The mounts 123 may correspond to the attachments 74 and employ the
same mechanisms as shown in FIG. 10. Identical slots 78 in the floor 32 or the
restraining flanges 33 may cooperate with the slots 78 in the containers 105
and
couplers 84 to restrain the containers and integrate the structures thereof
with the spine
structure 120.
[0078] The effectiveness with which the cargo assembly is able to share in the
aerodynamic load with the spine and the wings depends on the efficient
distribution of
this load onto the individual cargo containers. The efficient distribution of
this load, in
turn, depends on the extent to which the cargo containers are structurally
integrated
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with one another. The extent of this integration may be augmented by
increasing the
number of attachment points between the cargo containers. FIG. 11 depicts a
cargo
container 600 which comprises multiple attachment points via corner
attachments 610,
side attachments 620 and panel attachments 630. These attachments may be used
to
structural integrate the cargo container 600 with either the aircraft spine or
to other
cargo containers or frame assemblies of like or different sizes.
[0079] The modular design of the frame assemblies and the cargo containers
allows great flexibility in assembling a cargo assembly that is mounted onto
the aircraft
spine. For example, a cargo assembly may comprise: (a) only structural frame
assemblies which, in turn, are comprised of structural frame elements of
various shapes
and sizes; (b) only cargo containers of various shapes and sizes or (c)
combinations of
(a) and (b). Where the cargo assembly is comprised of combinations of
structural frame
assemblies and cargo containers, any number of configurations and arrangements
are
possible. Additional fittings may be provided as required by higher weight
cargo.
[0080] FIGS. 12A-B depict cargo assemblies 700A, 700B comprising both cargo
containers 710 and structural frame assemblies 760. The cargo containers 710
and
structural frame assemblies 760 each comprise a plurality of comer attachments
712
and side attachments 714. In the embodiment depicted in FIGS. 12A-B, the frame
assemblies 760 are used to carry bladders 770. The bladders 770 may be used to
carry a liquid or even additional fuel for the cargo aircraft. In embodiments
where the
bladder 770 is used to carry fuel, a supply conduit may be provided between
the
bladder 770 and the aircraft engine. Because such fuel transfers will change
the weight
distribution of the cargo assembly and thus the center of gravity of the
aircraft, the
arrangement shown in FIG. 12A is preferred, wherein the bladders 770 are
located at
the aircraft's center of gravity.
[0081] Under certain circumstances, it may be desirable to have a dynamic
system for adjusting an aircraft's center of gravity. This may be desirable in
situations
where there are changes in the weight distribution of the aircraft during
flight. In such
embodiments, the cargo assembly of FIG. 12B may further comprise a conduit
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connecting the front and aft bladders 770 and liquid may be distributed
therebetween to
achieve the desired center of gravity. The conduit may be controlled by a
central
computer either onboard the aircraft or at a remote central command station to
transport
a desired volume of fluid to achieve the desired center of gravity.
[0082] It is understood that the modular units comprising the final cargo
assembly
is preferably arranged and distributed within the cargo assembly based on
obtaining a
center of gravity of the aircraft within a range acceptable for flight. Thus,
the modular
units having the highest maximum cargo loads may be arranged at or near the
center of
gravity of the unloaded aircraft. The entire contents of U.S. Patent
Application Serial
No. 11/935,328, published under 2009/0114773, is incorporated herein by
reference in
its entirety.
[0083] In preferred embodiments of the cargo assembly, the modular frame and
container units are mated and attached together in a manner that they act as a
single
assembly to share the flight load with the spine and wings. To that end, it is
desirable to
maximize the number and area of attachment points between the modular frame
and
container units. At the very least, the modular units are connected to one
another via
corner fittings. Preferably, however, the modular units are connected to one
another via
additional fittings and assemblies.
[0084] FIGS. 13 through 15 depict means by which adjacent modular container
and frame units may be connected to effectuate a more efficient and
distributed load
transfer, thereby providing a structurally integrated cargo assembly.
[0085] FIGS. 13A-B depict a connecting hinge assembly 800 to provide a further
means of structurally coupling individual cargo containers 810A, 810B to
enable a more
efficient load transfer between adjacent modular units. The connecting hinge
assembly
800 comprises a plurality of raised tubes 820 configured to interlock adjacent
modular
units 810A, 8108. Each one of the raised tubes 820 are configured to
accommodate a
rod 850 which is threaded through raised tubes 820 of adjoining cargo
containers 810A,
810B to structurally couple the cargo containers 810A, 810B along its edges.
The
connecting hinge assembly 800 increases the contact points between adjacent
modular
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units, resulting in a more efficient and distributed load transfer between the
adjacent
modular units.
[0086] Tensioning wires or rods may further be provided with the cargo
assembly. FIGS. 14A-14D depict a tension assembly 950 that may be used in
connection with the modular frame and container units disclosed herein. As
shown in
FIGS. 14A-14D, each modular unit may comprise one or more tension assemblies
950.
The tension assembly 950 may be included in the modular units to further
assure that
loads are transferred when a bulkhead is not present. The rods or cables
stabilize the
cargo assembly structure by transmitting loads across a face of the container
to which it
would otherwise not be transmitted in the absence of the rods or cables.
[0087] The tension assembly 950 facilitates the transfer of load across the
cargo
assembly which, as shown in FIG. 14A, may comprise multiple modular units
coupled
together (900A, 9008, 900C) or a single cargo unit (900D). It is understood
that the
tension assembly 950 may be provided at various locations within the cargo
unit
including the sidewalls.
[0088) FIG. 14B shows a cargo container 910 comprising frame members 930
and a tension assembly 950 disposed in the middle of the cargo unit 910. The
cargo
container 910 further comprises eight corner attachments 912 and a plurality
of side
attachments 914. Fairings 920 are coupled to the frame members 930 to enclose
the
internal cavity of the cargo unit 910. The fairings 920 further comprise
cutouts 922 to
expose the corner attachments 912 and the side attachments 914 when the
fairing 920
is coupled to the frame members 930.
[0089] FIGS. 14C-D show an embodiment of the tension assembly 950 in greater
detail. The tension assembly 950 comprises a pair of diagonally intersecting
rods 952
that couple opposing corners defined by the frame members 930 of the cargo
unit. The
diagonally intersecting rods 952 intersect through a stabilizing hub 954. The
ends of the
rods 952 each comprise a threaded portion 954 which is inserted into an
anchoring
corner sheath 956 attached to the four comers defined by the frame members
930. The
tension exerted by the tension assembly 950 may be increased by turning the
rods 952
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in one direction and may be decreased by turning the rods 952 in the opposite
direction.
In some embodiments, the center stabilizing feature may not be needed.
[0090] Splices may optionally be provided along the sides of the cargo
assembly
that is not attached to the spine. The splices may provide additional
structural support
and help transfer the load between cargo containers in the cargo assembly.
[0091] FIG. 15A-15B depict a cargo assembly 1000 comprising a plurality of
cargo containers 1010. The cargo containers 1010 are coupled to one another
via
facing corner attachments 1012 and optionally via facing side attachments 1014
via
couplers (not shown). Corner splices 1060 may be attached along the length of
the
corner edge of the cargo assembly 1000 via a plurality of splice bolts 1080.
The splice
bolts 1080 each further comprise an attachment face 1012 which structurally
connect
the splice to the container assembly. A center splice 1050 may further be
attached
along the length of the two facing corner edges of the cargo containers 1010
in the
same manner. It is also understood that the splices 1050, 1060 may be attached
at any
location along the container assembly via a threaded screw.
[0092] While FIGS. 15A-15B depict the center splice 1050 and corner splices
1060 as extending the entire length of the cargo assembly, it is understood
that the
splices may extend only a portion of this length. The splices augment the
structural
rigidity of the cargo assembly 1000 and reinforce the connection and the load
transfer
between the individual cargo containers 1010. Additional splices may added off-
center
or on the vertical walls or even perpendicular to the long axis of the spine.
Alternatively,
cables could be used with fittings at the ends to tie them to the container
assembly.
[0093] It is to be understood that the detailed description and specific
examples,
while indicating preferred embodiments of the present invention, are given by
way of
illustration and not limitation. Many changes and modifications within the
scope of the
present invention may be made without departing from the spirit thereof, and
the
invention includes all such modifications.
