Note: Descriptions are shown in the official language in which they were submitted.
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SHIELD KITS FOR PROJECTILE PROTECTION
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application hereby claims priority to United Kingdom Patent
Application No. , filed on May 17, 2011, which is incorporated herein in its
entirety by reference.
TECHNICAL FIELD
[0002] The following disclosure relates generally to shield kits for vehicles
and
structures, and associated systems and methods.
BACKGROUND
[0003] Shaped-charge warheads, such as RPGs, are capable of penetrating steel
armor and pose a particular problem for tanks and armored personnel carriers
(APC) in
combat situations. A shaped-charge warhead consists of a cone shaped warhead
having
a quantity of explosive disposed behind a hollow space. The hollow space is
typically
lined with a compliant material, such as copper. When detonated, the energy is
concentrated to the center of the charge and is sufficient to transform the
copper into a
thin, effectively liquid, shaped-charge jet having a tip speed of up to 26,000
mph. The
extremely high pressures generated cause the target material to yield and flow
plastically,
with devastating effect. To be most effective the shape and structure of the
cone of the
shaped-charge must be in tact at detonation. If the shape is somehow altered,
the
shaped-charge jet will not have formed properly before hitting the surface and
the effect
will be lessened.
[0004] Conventional shields for defending against shaped-charge warheads make
use of the fact that the shape of warheads enables the warheads to "jet" or
penetrate
heavy armor. By providing an outer shield at a short distance from the actual
armor of the
vehicle or other structure that can deform or crumple the cone of the warhead,
it is
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possible to cause the warhead to fail or dud, with the effect that the full
design of the
charge is thwarted. In effect, the warhead becomes a conventional grenade,
rather than a
shaped-charge.
[0005] Any outer shield that interrupts the detonation design of the shaped-
charge will
offer some degree of protection. The shield itself merely needs to deform or
crumple a
portion of the cone of the shaped charge, reducing the impact of the shaped
charge to a
simple grenade; it is not meant to act as additional armor. In recent times it
has become
common to fit so-called "bar armor" to tanks and other military vehicles. Bar
armor
includes a metal frame which is mounted at a distance of approximately 1.5
feet from the
vehicle. The frame includes a plurality of horizontal struts or bars which are
spaced apart
at a distance selected to prevent penetration by shaped-charge warheads. When
the
shaped charge strikes the bar armor, the bar armor deforms the charge and
interferes with
the design of the detonation, reducing the damage from the shaped-charge. One
disadvantage of bar armor is that it is relatively heavy and adds a great deal
of weight to
an already heavy vehicle. In addition, bar armor cannot easily be replaced or
repaired in
the field.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 is an isometric view of a vehicle having a plurality of
flexible
shields replacing damaged portions of a bar armor system according to an
embodiment of
the present disclosure.
[0007] Figure 2 is a front elevation view of one of the flexible shields of
Figure 1
configured according to an embodiment of the present disclosure.
[0008] Figure 3 is an isometric view of a cable support system for use with
the flexible
shields of the present disclosure.
[0009] Figure 4 is a front perspective view of an installed flexible shield
having a
cable-reinforced seam configured according to an embodiment of the present
disclosure.
[0010] Figure 5 is an isometric view of a seam between two shields configured
according to another embodiment of the present disclosure.
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[0011] Figure 6a is an isometric view of a shield kit configured according to
an
embodiment of the present disclosure.
[0012] Figure 6b is an isometric view of the shield kit of Figure 6a packaged
for in-
field deployment and configured according to an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0013] The present disclosure relates to various embodiments of flexible
shields and
shield systems which may be used to protect a target, such as a vehicle,
building or other
structure, from damage caused by a projectile, such as a rocket propelled
grenade (RPG)
or other shaped-charge. The shields of the present disclosure can be used as
replacement shields for bar armor systems configured to interrupt the design
of detonation
of warheads, rendering them significantly less powerful than intended. The
shields can be
small and lightweight for portability and relatively easy in-field
installation. Many specific
details are set forth in the following description and in Figures 1-6b to
provide a thorough
understanding of various embodiments of the disclosure. Other details
describing well-
known structures and systems often associated with bar armor systems, however,
are not
set forth below to avoid unnecessarily obscuring the description of the
various
embodiments of the disclosure.
[0014] Many of the details and features shown in the Figures are merely
illustrative of
particular embodiments of the disclosure. Accordingly, other embodiments can
have other
details and features without departing from the spirit and scope of the
present disclosure.
In addition, those of ordinary skill in the art will understand that further
embodiments can
be practiced without several of the details described below. Furthermore,
various
embodiments of the disclosure can include structures other than those
illustrated in the
Figures and are expressly not limited to the structures shown in the Figures.
Moreover,
the various elements and features illustrated in the Figures may not be drawn
to scale.
[0015] Figure 1 is an isometric view of a vehicle 110 having a plurality of
flexible
shields 140 (identified individually as first shield 140a and second shield
140b) replacing
damaged portions of a bar armor system 100 according to embodiments of the
present
disclosure. The flexible shields 140 can be the same as or similar to the
textile armor
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described in U.S. Patent Application Serial No. 10/584,605, filed August 9,
2007,
published as U.S. Patent Application Publication No. 2009/0217811, claiming
priority to
GB Patent Application No. GB 0601030.0, filed January 17, 2006, both of which
are
incorporated herein by reference in their entirety. The bar armor system 100
can include
conventional armor bars or slats 124 suspended from a perimeter frame 121 that
is
attached to the vehicle 110 by standoff arms 122 (shown in Figure 1). The
standoff arms
122 project outward from the vehicle 110 a predetermined standoff distance,
such as
about one foot or more. The standoff distance can vary depending on the nature
of the
expected projectile attack and on the dimensions of the vehicle 110. The bars
124, the
frame 121, and the standoff arms 122 are collectively referred to herein as
armor 120.
The armor 120 can be divided into discrete panels 123, each panel being
defined by a
section of the frame 121 and covered by the bars 124. Virtually any suitable
panel
dimension and bar shape and size can be used. In some embodiments, one of the
panels
123 covers the entire rear, side, or front of the vehicle 110. In other
embodiments, the
individual panels 123 cover a smaller area of the vehicle 110, and in some
cases two or
more of the panels 123 together cover the entire rear, side, or front of the
vehicle 110.
[0016] The armor 120 is configured to substantially cover the vehicle 110 from
anticipated angles of attack. In some embodiments, the angle of attack cannot
be
anticipated so the armor 120 can cover the entire vehicle 110. In other
embodiments,
such as shown in Figure 1, a lower perimeter of the vehicle 110 is covered by
the armor
120 in anticipation that an attack will come from the ground and not the air.
[0017] When a projectile such as a shaped charge strikes the armor 120, the
shaped
charge is deformed by the armor 120, thus preventing the shaped charge from
"jetting."
The projectile's destructive power is therefore reduced to generally
equivalent to a hand
grenade, which can be withstood by the conventional armor of the vehicle 110.
However,
the armor 120 may be damaged or otherwise rendered inoperable by the blast.
Other
circumstances can also damage the armor 120, such as contact with rough
terrain.
Carrying replacement bars or slats for such a contingency is generally
impractical. The
shields 140 of the present disclosure, however, can be packaged in a kit,
conveniently
carried on board the vehicle 110, and deployed in the field to cover an
exposed portion of
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the vehicle 110 when a portion of the armor 120 is damaged. The shields 140
can be
flexible shields and can therefore cover panels 123 of varying sizes. For
example, in the
illustrated embodiment the first shield 140a can protect a portion of the
front of the vehicle
110, and the second shield 140b can protect a side of the vehicle 110. The
size and
attachment points of the shields 140a, 140b when installed may vary according
to the size
of the damaged area of the armor 120. In some embodiments, the first shield
140a and
second shield 140b are similar in size before deployment and are packaged
similarly.
[0018] Figure 2 is a front elevation view of one of the shields 140 of Figure
1
according to an embodiment of the present disclosure. In some embodiments, the
shield
140 is made from a textile material such as a net having interwoven strands
141 forming
square, diamond, or hexagonal holes between the strands 141. The holes can
range from
about 0.5 inch to 2.5 inches, or about one inch across. The size of the holes
in the shield
140 can be selected to defeat a particular type of shaped charge. For example,
the holes
in the shield 140 can be made slightly larger than a nose of an expected
shaped charge
projectile, but smaller than the body of the shaped projectile. The strands
141 can be
made of various suitable materials, including flexible, lightweight materials
such as
polyethylene (e.g., high molecular weight polyethylene). In some embodiments,
the
strands 141 do not stretch appreciably and therefore interrupt the designed
detonation of
the projectile.
[0019] The strands 141 can be aligned in a first direction, wherein each
strand 141 is
woven with adjacent strands 141 alternating left and right along the length of
the strand
141, with a knotless intersection between strands 141, similar to chicken wire
or a chain-
link fence. In general textile terminology, these strands 141 are known as
warp strands.
In general, warp strands of a textile are woven in a first direction, and the
textile can
optionally include weft (or fill) strands interwoven with the warp strands in
a second
direction transverse to the first direction. In some embodiments, the shield
140 is a textile
having warp strands 141 and does not include weft strands. In other
embodiments, the
shield 140 includes both warp strands 141 and weft strands (not shown).
[0020] In embodiments in which the shield 140 is a net having holes, any
suitable
hole can be used as an attachment point for fastening the shield 140 to the
frame 121.
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Fasteners 142 such as cable ties (e.g., zip ties) or other suitable strap
fasteners can
extend through a hole in the shield 140 and around a portion of the frame 121
to hold the
shield 140 to the frame 121. The size of the deployed shield 140 can therefore
be
adjusted to fit any size of breach in the armor 120 with any suitable level of
tension by
selectively installing fasteners 142 in available holes and securing the
shield 140 to the
frame 121. In other embodiments in which the shield 140 includes tightly-woven
warp
strands 141 and weft strands (not shown) without holes, the shield 140 can
include loops
or eyelets or other suitable attachment points (not shown) at any suitable
position,
including around a periphery of the shield 140, that can engage the fasteners
142 to
attach the shield 140 to the frame 121.
[0021] The shield 140 can be pulled taut across the frame 121 and fastened
with an
appropriate amount of slack so that the shield 140 deflects a small amount,
but less than
the standoff distance, when a projectile strikes the shield 140. An operator
can perform a
convenient test for the proper slack by pressing on the shield 140 with his
hand. The
shield 140 can be sufficiently taut that the shield 140 deflects slightly, but
the operator's
hand does not reach more than about half the standoff distance between the
shield 140
and a hull or sidewall of the vehicle 110. This test can be performed in the
field without
using tools or any other specialized equipment.
[0022] Figure 3 is an isometric view of a first cable 144, second cable 145,
and a
cable joiner 146 for use with the shield 140 configured according to
embodiments of the
present disclosure. The cables 144, 145 can be made of steel, polyethylene,
cable,
and/or other suitable materials. The cable joiner 146 can include two through-
holes or
channels configured to receive the first and second cables 144, 145 extending
therethrough. The channels can be mirrored on opposite sides of the cable
joiner 146 to
receive the first and second cables 144, 145. The cable joiner 146 can have
spring-
loaded rollers or wedges in the channels configured to permit the cables 144,
145 to move
through the cable joiner 146 in one direction only and grip the cables 144,
145 when
pulled in the opposite direction. In some embodiments, the cable joiner 146 is
a
conventional gripple as provided by, e.g., Gripple Ltd. of Sheffield, England.
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[0023] The cables 144, 145 can be fastened to opposing portions of the frame
121
shown in Figure 2. In some embodiments, a first portion 144a of the first
cable 144
extends between the frame 121 and the cable joiner 146, and a second portion
144b of
the first cable 144 is trimmed near the cable joiner 146. A first portion 145a
of the second
cable 145 can similarly extend between the frame 121 and the cable joiner 146,
and a
second portion 145b of the second cable 145 can also be trimmed near the cable
joiner
146. The first portions 144a, 145a can be tensioned by pulling the second
portions 144b,
145b away from the cable joiner 146 as shown by arrows A. In some embodiments,
the
cables 144, 145 can be interwoven with the shield 140. In other embodiments,
the shield
140 can be attached to the cables 144, 145 with the fasteners 142 via holes,
loops,
eyelets, or another suitable attachment point on the shield 140 as described
above.
[0024] In some embodiments, the second portions 144b, 145b of the first and
second
cables 144, 145 can be secured to other portions of the frame 121 to pull the
cables 144,
145 away from the shield 140 to further tension the shield 140. The shield 140
can
therefore be enlarged and shaped. For example, an edge 143 of the shield 140
can be
non-linear, following the shape of the first portions 144a, 145a of the cables
144, 145.
This method can also be used to achieve proper tension in the shield 140. The
cables
144, 145 therefore form a replacement frame that holds the shield 140 in
place.
Accordingly, even when a portion of the frame 121 is damaged or missing, the
cables 144,
145 support the shield 140 with a desired tension in the shield 140.
[0025] Figure 4 is a front perspective view of a shield installation with a
cable-
reinforced seam 200 configured according to an embodiment of the present
disclosure.
The first and second shields 140a, 140b can be fastened to the frame 121 with
a plurality
of the fasteners 142 installed along three sides of each shield 140a, 140b
with the
remaining side of the shields 140a, 140b positioned adjacent to one another in
the middle
of the frame 121. A first cable 144 can be fastened to the frame 121 at a
first cable
attachment point 150, and a second cable 145 can be fastened to a second cable
attachment point 151 opposite the first cable attachment point 150. In some
embodiments, the first and second cables 144, 145 can be wrapped around any
available
portion of the frame 121 and tied off. In other embodiments, the first and
second cable
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attachment points 150, 151 can be specifically designed to engage and anchor
the
respective end portions of the cables 144, 145. For example, in some
embodiments the
cable attachment points 150, 151 can be knobs, hooks, or cleats.
[0026] The cables 144, 145 can be woven through holes along the adjacent edges
of
the shields 140a, 140b and joined together with the cable joiner 146 and
tensioned as
described above. The second portions 144b, 145b of the first and second cables
144, 145
can either be trimmed or can be attached to some portion of the frame 121 or
the shields
140a, 140b.
[0027] The first and second shields 140a, 140b together form a composite
shield
140c covering the entire panel 123. The cables 144, 145 provide additional
rigidity and
tension to the composite shield 140c. In some embodiments, the seam 200 can be
used
when a portion of the frame 121 is missing. For example, when a portion of the
frame 121
between adjacent panels 123 (see Figure 1) may be missing or damaged.
Accordingly,
the composite shield 140c and cable-reinforced seam 200 can be used to cover
the
vehicle 110 when portions of the frame 121 are unavailable.
[0028] Figure 5 is an isometric view of a shield seam 300 configured according
to
another embodiment of the present disclosure. In this embodiment, the
fasteners 142 can
directly attach the first shield 140a to the second shield 140b, without using
a cable or
cable joiner. More specifically, the operator can pull the shields 140a, 140b
together with
the desired tension and place the fasteners 142 at any appropriate hole of the
shields
140a, 140b to maintain the desired tension.
[0029] Figure 6a is an isometric view of a kit 160 according to embodiments of
the
present disclosure. The kit 160 includes a shield 140 that is wrapped or
rolled into a
compact package, fasteners 142, a cable 144, and cable joiners 146. The kit
160 can
also include a desiccant material 145, any suitable printed instructions 147,
and a marker
148 for indicating when the shield 140 was installed or other information. In
some
embodiments, the kit 160 weighs approximately 3.5 pounds and is therefore
easily
portable. In other embodiments including a larger shield 140, the kit can be
approximately
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7 pounds. Figure 6b is an isometric view of the kit 160 of Figure 6a as
packaged
conveniently for deployment in the field.
[0030] From the foregoing, it will be appreciated that specific embodiments
have
been described herein for purposes of illustration, but that various
modifications may be
made without deviating from the spirit and scope of the various embodiments of
the
disclosure. For example, the shields can be made of various suitable materials
and can
have various dimensions. Moreover, specific elements of any of the foregoing
embodiments can be combined or substituted for elements in other embodiments.
Certain
aspects of the disclosure are accordingly not limited to automobile or
aircraft systems.
Furthermore, while advantages associated with certain embodiments of the
disclosure
have been described in the context of these embodiments, other embodiments may
also
exhibit such advantages, and not all embodiments need necessarily exhibit such
advantages to fall within the scope of the invention. Accordingly, the
disclosure is not
limited, except as by the appended claims.
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