Note: Descriptions are shown in the official language in which they were submitted.
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VEHICLE FLOOR
TECHNICAL FIELD
[0002] The present disclosure relates to a blast absorbing structure and
system for use in
decreasing the extent of catastrophic injury to the occupants of a vehicle,
including a military
vehicle subjected to a blast. More specifically, the structure and system
absorbs the energy from
a blast before it reaches the lower extremities of the occupants in the
vehicle cabin.
BACKGROUND
[0003] Armored vehicles are frequently threatened by improvised explosive
devices (IEDs)
designed to cause harm to the vehicle and its occupants. IEDs are typically
one or more grouped
artillery shells redeployed and detonated in an effort to inflict casualties.
These explosive
devices when detonated beneath a floor of a vehicle often create localized
deformation of the
floor of the vehicle thereby transmitting large vertical loads onto the lower
extremities of
occupants of the vehicle. For example, detonations below the underbelly of an
armored vehicle
may cause the vehicle floor to accelerate at 100G or more and reach velocities
of 7 to 12 m/s
over a time period of 3 to 5 msec. These high rates of acceleration and
velocity transmit large
mechanical forces on the lower extremities of the occupants within the vehicle
cabin, often
resulting in catastrophic injury or worse.
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[0004] Armor countermeasures typically consist of heavy metal plates placed
between the
threat and the vehicle in such a way as to resist hull breach and aggressive
floor accelerations.
These heavy metal plates also work in concert with layers of additional metal,
ceramic,
composite or plastic materials designed to prevent lethal high velocity
fragments from entering
the vehicle. The heavy metal plates are typically mounted to the underside of
the vehicle in
shapes to take advantage of venting efficiency, inherent geometric stiffness,
and deflection
characteristics when presented with incoming pressure and fragmentation.
Carrying a heavy
blast and fragment resistant hulls results in significant performance
disadvantage to the vehicle
in terms of reduced fuel economy, lost cargo capacity and increased
transportation shipping
costs.
[0005] In addition to the outer metal plates, the interior of the personnel
cabin may include a
blast mat. During a blast event on an armored vehicle, the lower extremities
of the occupants of
the vehicle are frequently subjected to injuries from the blast energy being
transmitted through
the vehicle structure. One current solution to dissipate the energy is to use
blast mats on the
floor where the occupants of the vehicle rest their feet. However, current
blast mats are
expensive and heavy, often contributing unwanted additional weight to an
already heavy vehicle.
[0006] Therefore, there is a need for an efficient, cost-effective energy
absorbing system for
use during a high acceleration event, such as a blast event underneath the
vehicle. The present
structure and system is usable, for example, in a personnel cabin of a
vehicle, specifically as a
floor, and includes an energy absorbing device for absorbing and dissipating
the blast forces
from an explosive device, thereby lessening the impact of the forces on the
lower extremities of
the occupants of the vehicle. The device includes energy absorbing supports, a
flat panel or
surface positioned on top of the supports, and at least one retainer or guide
to maintain the
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movement direction of the surface. The energy absorbing supports suspended the
top surface,
creating a "floating floor" to improve the absorption and dissipation of
forces exerted on the
underbelly of the vehicle during a blast event, while avoiding the negative
tradeoffs of
alternative designs.
SUMMARY
100071 There is disclosed herein a structure and system, each of which
avoids the
disadvantages of prior structures and devices while affording additional
structural and operating
advantages.
100081 Generally speaking, a blast absorbing structure for use in absorbing
blast forces
exerted on a floor of a personnel cabin of a vehicle is disclosed.
[0009] In an embodiment, the blast structure comprises a first absorption
component for
initial absorption of the blast forces exerted on the floor of the vehicle and
a second absorption
component for secondary absorption of the blast forces, wherein the first and
second absorption
components cooperatively move between an initial position and a blast force
position to diminish
the blast forces prior to the blast forces to reaching an occupant of the
cabin.
[0010] In another embodiment, a blast absorbing system for use on a floor
of a personnel
cabin of a vehicle, is disclosed. The system comprises at least one energy
absorbing component,
a floating surface supported by the energy absorbing component, the floating
surface moveable
between an initial position and a blast force position, and a guide for
retaining the floating
surface in a horizontal position, wherein upon receipt of a blast force upon
the floor, the energy
absorbing components deform to absorb the blast force and diminish movement of
the floating
surface from the initial position to the blast force position.
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[0011] These and other features and advantages of the present
structure and system can be
more readily understood from the following detailed discussion with reference
to the appended
drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of the blast absorbing structure
in use;
[0013] FIG. 2 is a side view of the blast absorbing structure of the
present disclosure;
[0014] FIG. 3 is a side view of blast absorbing structure during the
initial phase of a blast
event;
[0015] FIG. 4 is a side view of the blast absorbing structure after
the initial blast phase;
[0016] FIG. 5 is a top view of the blast absorbing structure;
[0017] FIG. 6 is a bottom view of the blast absorbing structure; and,
[0018] FIG. 7 is a side view of the blast absorbing structure showing
the guides.
DETAILED DESCRIPTION
[0019] Referring to FIGS. 1-7, there is illustrated an exemplary
embodiment of an blast
energy absorbing structure and system, generally designated by the numeral 10,
as well as the
components thereof. The structure 10 is designed for use as a blast energy
absorbing system on
the cabin hull or lower floor structure 12 of a personnel cabin 14 of a
vehicle (not shown). The
blast energy absorbing structure is particularly useful on a military vehicle,
which is used in war-
zones for transporting personnel or cargo. This structure 10 will absorb
energy from a blast, thus
lessening the impact on the vehicle occupants' lower extremities, which rest
on the structure,
thereby reducing injury to the occupants.
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[0020] As shown in FIGS. 1 and 2, the structure includes at least one
energy absorbing
support 20, which may also be referred to as a first absorption component.
Although the present
disclosure includes four supports, one at each corner of the structure 10, it
should be understood
that any number of supports may be used. Additionally, the energy absorbing
support 20 may
have any suitable shape, including but not limited to that of a pillar, square
or rectangle (FIGS. 2
-7) or a triangle or tapered side shape (FIG. 1). The energy absorbing support
20 are positioned
directly on the lower floor structure 12 of the cabin 14, and can be secured
through any suitable
fastener device including, but not limited to screws, bolts or studs.
Optionally, the supports 20
may be integrated into the lower floor structure 12 of the cabin.
[0021] The energy absorbing support 20 can be constructed from any
suitable material such
as a foamed material, including, but not limited to foamed aluminum, aluminum
honeycomb,
synthetic foams, such as polystyrene and/or polyethylene, other plastics, etc.
Regardless of the
material used for the supports, the material must be able to both support the
normal walking
loads (for example, a 300 pound load spread over a foot pressure
representative area results in a
deflection characteristic of existing production vehicle floors) and within a
common specified
working temperature range (-50 F to 160 F). Finally, the material must
progressively crush
during a blast load.
[0022] As shown in FIGS. 2-7, the structure 10 includes a top panel or
surface 30 supported
on the plurality of energy absorbing supports 20. The surface 30 is designed
to "float" above the
cabin hull or lower floor structure 12 of the vehicle. As illustrates, there
is a deliberate air space
22 between the surface 30 and the lower floor structure 12 of the cabin. As
will be explained
below, the panel or surface 30 is not in a fixed position, which allows the
surface to move in
response to a blast event. In addition to being a second energy absorbing
component, the surface
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30 serves as a walking surface, essentially a floor, within the interior of
the cabin. As shown in
FIGS. 2-4, the surface 30 is in direct contact with the lower extremities of
the occupants of the
vehicle, as the occupant's feet 16 rest directly on this surface.
[0023] The surface 30 or second absorption component can be constructed
from a variety of
material, including, but not limited to steel, aluminum, aluminum honeycomb,
and any variety of
plastics and composites of the same. Construction of the surface can be
accomplished by any
suitable method including cutting, metal molding, plastic injection molding,
forming, bonding
welding, etc.
[0024] As illustrated in FIGS. 3 and 4, the energy absorbing supports 20
and floating surface
30, work together to lessen in impact of a blast on the lower extremities of
the occupants of the
vehicle. In particular, immediately after an explosive blast, all of the
components naturally move
in an upward direction. It is this accelerated, upward movement of the floor
structure during a
blast that can cause catastrophic injuries to the lower extremities. However,
in the present
disclosure, the energy absorbing supports 30 crush in advance of the blast
energy reaching the
floating support, and thus, the floating support moves upward less quickly,
lessening the impact
of the blast on the lower extremities of the occupants. In addition, the air
space 22 between the
lower floor structure 12 of the cabin and the floating surface 30 provides an
area to slow the blast
forces.
[0025] In addition to the energy absorbing supports 20 and the moving floor
30, the structure
also includes a guide or retainer. Specifically, and as shown in FIGS. 5-7,
there are several
guides in the present system. The guides include retention plate 40, lateral
guide 42 and fore/aft
guides 44. The guides limit movement of the floating surface 30 generally
during both blast and
non-blast events. For example, because the floating surface 30 also acts as a
walking floor, it
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should maintain some stability for walking, rather than constantly moving from
the pressure of
being walked upon. Therefore, the lateral guide 42 keeps the surface 30 from
moving laterally,
while the side guides 44 prevent the surface from moving fore and aft. The
retention plate 40 not
only compliments the lateral and side guides to secure the surface, but also
prevents the surface
from being propelled into the interior of the cabin during a blast event.
However, the guides do
not keep in the floating surface 30 in such a secured position that it cannot
move in response to
the crush of the energy supports 20 during a blast event.
[0026] In operation, and as described, the various components of the blast
absorbing
structure and system 10 work separately and in conjunction to dissipate at
least some of the
energy exerted on the underbelly of a vehicle cause by, for example, the
explosion of an IED
below the vehicle. In various exemplary embodiments, when an IED, or similar
explosive
device, is detonated below the vehicle, the force of the explosion causes the
lower floor structure
12 of the vehicle to deform. This deformation in turn forces the floor against
the lower
extremities of any occupants of the vehicle. The blast absorbing system
deforms and slows the
upward motion of the force to help dissipate the force being exerted on the
lower extremities of
the occupants, thereby reducing the likelihood of injury to the occupants.
[0027] It should be appreciated that the above-referenced forces may
include general
deformation forces, localized deformation forces, general displacement forces,
localized
displacement forces, or any other force that may be exerted upon the
underbelly of a vehicle.
[0028] It should also be appreciated that, while the above discussion is
related to deformation
forces caused by, for example, IED explosions, embodiments described herein
may be usable to
dissipate other forces, such as, for example, blunt forces impacts, grenade
detonations, small
arms fire, and any other force that may be exerted upon the underbelly of a
vehicle.
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