U.S. patent application number 13/415464 was filed with the patent office on 2012-09-27 for composite grille louvers.
Invention is credited to Mike Iwen, Quan Nguyen, Torrey Pike, David Arthur Schade, George Thomas.
Application Number | 20120240757 13/415464 |
Document ID | / |
Family ID | 46876199 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120240757 |
Kind Code |
A1 |
Schade; David Arthur ; et
al. |
September 27, 2012 |
COMPOSITE GRILLE LOUVERS
Abstract
A grille having a plurality of s-louvers shaped to increase the
efficiency of air flow through the grille without decreasing the
effectiveness of the louvers at stopping or deflecting projectiles.
Each louver has a hooked portion at the end of the louver to
present a ballistic hook for stopping projectiles ricocheting
through the circuitous path defined between the louvers. An insert
having a closeout for covering the ballistic hook is positioned
within each hooked shape portion to eliminate the eddy or stall
created at the end of the circuitous path by ballistic hook. The
closeout can be penetrated by projectiles ricocheting through the
circuitous path such that the ballistic hook can still capture
projectiles within the inlet.
Inventors: |
Schade; David Arthur;
(Belmont, CA) ; Pike; Torrey; (Danville, CA)
; Thomas; George; (Palo Alto, CA) ; Nguyen;
Quan; (Stockton, CA) ; Iwen; Mike; (Campbell,
CA) |
Family ID: |
46876199 |
Appl. No.: |
13/415464 |
Filed: |
March 8, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61467605 |
Mar 25, 2011 |
|
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|
Current U.S.
Class: |
89/36.02 ;
89/903; 89/918 |
Current CPC
Class: |
F41H 5/026 20130101 |
Class at
Publication: |
89/36.02 ;
89/903; 89/918 |
International
Class: |
F41H 5/02 20060101
F41H005/02; F41H 7/00 20060101 F41H007/00 |
Claims
1. A ballistic grille for preventing projectiles from entering a
protected vehicle compartment through an air supply vent while
allowing air to flow into the protected compartment through the
vent, comprising: a plurality of S-shaped louvers each having an
exterior end and an interior end, wherein each louver further
comprises a hook portion at the interior end defining an inlet in
the louver to form a ballistic hook for catching projectiles; and a
plurality of inserts comprising a closeout permeable by
projectiles, wherein each insert is affixed to the hook portion of
a corresponding louver; wherein the S-shaped louvers are arranged
in an overlapping configuration to define a plurality of circuitous
paths through the vent between the louvers and to deny projectiles
a linear path through the vent, wherein the inserts are positioned
to enclose the inlet and the ballistic hook to maintain a
continuous flow of air through the corresponding circuitous
path.
2. The ballistic grille of claim 1, wherein the exterior end of
each louver comprises 1 tapered shape to facilitate the flow of the
air into the circuitous paths.
3. The ballistic grille of claim 1, wherein each closeout forms an
enclosed air pocket within the corresponding inlet.
4. The ballistic grille of claim 1, wherein each insert further
comprises a foam core positioned within the corresponding inlet,
wherein the foam core comprises a lower density material than the
louver such that projectiles can penetrate the foam core.
5. The ballistic grille of claim 4, wherein the foam core comprises
a closed-cell foam material.
6. The ballistic grille of claim 1, wherein the louver comprises a
composite material combining a fibrous material and a matrix
material.
7. The ballistic grille of claim 6, wherein the fibrous material is
selected from a group consisting of aramid, S2 glass fibers and
combinations thereof.
8. The ballistic grille of claim 6, wherein the fibrous material
comprises about 60-80 wt % of the composite material and the matrix
material comprises about 20-40 wt % of the composite material.
9. The ballistic grille of claim 1, further comprising a plurality
of hardened bars positioned proximate to the external ends of the
louvers for fracturing and eroding incoming projectiles before the
projectiles reach the louvers.
10. The ballistic grille of claim 1, further comprising a honeycomb
mesh positioned proximate to the internal ends of the louvers for
capturing projectiles that ricochet through the circuitous
paths.
11. A louver for preventing projectiles from entering a protected
vehicle compartment through an air supply vent while allowing air
to flow into the protected compartment through the vent,
comprising: an exterior end; an interior end having a hook portion
defining an inlet in the louver to form a ballistic hook for
catching projectiles; and an insert having a closeout permeable by
projectiles enclosing the inlet and ballistic hook; wherein the
louver comprises an s-shape such that the louver can be arranged in
an overlapping configuration with other S-shaped louvers to define
at least one circuitous path through the vent between the louvers
and to deny projectiles a linear path through the vent; wherein the
insert prevents the ballistic hook from disrupting the flow of air
through the circuitous path.
12. The louver of claim 11, wherein the exterior end comprises a
tapered shape to facilitate the flow of the air into the circuitous
path.
13. The louver of claim 11, wherein the closeout forms an enclosed
air pocket within the corresponding inlet.
14. The louver of claim 11, wherein the insert further comprises a
foam core positioned within the corresponding inlet, wherein the
foam core comprises a lower density material than the louver such
that projectiles can penetrate the foam core.
15. The louver of claim 14, wherein the foam core comprises a
closed-cell foam material.
16. The louver of claim 11, wherein the louver comprises a
composite material combining a fibrous material and a matrix
material.
17. The louver of claim 16, wherein the fibrous material is
selected from a group consisting of aramid, S2 glass fibers and
combinations thereof.
18. The louver of claim 16, wherein the fibrous material comprises
about 60-80 wt % of the composite material and the matrix material
comprises about 20-40 wt % of the composite material.
19. A method of preventing projectiles from entering an air supply
vent for a protected compartment, comprising: positioning a
plurality of S-shaped louvers in the vent, wherein each louver
comprises a hook shape portion defining an inlet in the louver to
form a ballistic hook for capturing projectiles; arranging the
S-shaped louvers in an overlapping arrangement to define a
plurality of circuitous routes through the vent for the passage of
air and denying projectiles linear paths through the vent; and
enclosing the inlet with a closeout permeable by a projectile to
prevent the ballistic hook from disrupting the air flow through the
circuitous route.
Description
RELATED APPLICATION
[0001] The present application claims the benefit of U.S.
Provisional Application No. 61/467,605 entitled "COMPOSITE GRILLE
LOUVERS, filed Mar. 25, 2011, which is incorporated herein in its
entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention is generally directed to ballistic
louvers permitting the flow of air through a vent while preventing
projectiles from entering the vent. Specifically, the present
invention is directed to ballistic louvers for improving air flow
through the vent while maintaining ballistic projection.
BACKGROUND OF THE INVENTION
[0003] Armored vehicles often have intake exhaust vents for
supplying air to engine components and other systems. However, if a
projectile enters the vent, the projectile can damage the engine or
other components. A grille having a plurality of louvers is
commonly fitted to the intake exhaust vents to prevent projectiles
from entering the engine compartment while permitting air to flow
between the louvers into the protected area. Grilles typically
comprise chevrons as shown in FIG. 1 or S-shaped louvers as shown
in FIG. 2 that are arranged in an overlapping configuration to
define a series of circuitous paths through the vent. As most
projectiles travel along a linear or nearly linear flight path, the
projectiles cannot navigate the non-linear paths without contacting
at least one louver. The louvers typically comprise materials such
as hardened steel or monolithic aluminum that can deflect, fragment
or capture the projectiles. Although the projectiles cannot easily
navigate the non-linear paths defined by the louvers, air can
easily flow through the non-linear paths.
[0004] The inherent tradeoff with a louver protected vent is that
improving protection for the vent typically worsens the air flow
through the vent. Increasing the number of louvers reduces the
likelihood that a projectile can successfully penetrate the vent,
but also reduces the cross-sectional area through which the air can
flow. While the circuitous flow paths do not block the air flow,
the supply of air to the engine compartment can be slowed if the
paths are too narrow. The slowed air supply can hinder the
performance of the engine components supplied by the vent. However,
reducing the number of louvers to increase the cross-sectional area
of the circuitous paths increases the likelihood that a projectile
will penetrate the grille and enter the engine compartment.
[0005] A common feature of S-shaped louvers is a hook shaped
portion, as shown in FIGS. 3-5 and as disclosed in U.S. Pat. No.
3,901,124, at the end of each louver to create an inlet and a
ballistic hook at the end of the circuitous path for capturing
projectiles or fragments that may have ricocheted through the
circuitous path. The reference is hereby incorporated by reference
in its entirety. The hooked shaped portion serves as a final
defense against projectiles passing through the vent. However, the
inlet and ballistic hook defined by the hooked shaped portion can
create a stall or eddy in the air flow through the circuitous path
upsetting the smooth air flow through the grille and creating a
large pressure drop across the vent.
[0006] A similar tradeoff is that increasing the size or number of
louvers can increase the weight and profile of the grille. As
disclosed in U.S. Pat. No. 5,753,847, a technique for improving the
protective ability of grille is to position an applique of hardened
steel bars in front of the louvers to fragment the projectiles
before the projectiles reaches the louvers to reduce the impact of
the projectile. The reference is hereby incorporated in its
entirety. However, the drawback of the bars is that the bars
significantly increase the weight and profile of the grill.
[0007] As such, there is a need for maintaining the protective
ability of the grille while improving the airflow through the
circuitous path. Similarly, there is a need for improving the
protective ability of the grille while reducing or maintain the
weight and profile of the grill.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to a grille having louvers
shaped to increase the efficiency of air flow through the grille
without decreasing the effectiveness of the louvers at stopping or
deflecting projectiles. Each louver comprises an S-shape with a
hooked portion at the end of the louver to present a ballistic hook
for stopping projectiles ricocheting through the circuitous path
defined between the louvers. An insert comprising a foam core and
covered by a closeout is positioned within each hooked shape
portion. The insert fills in the inlet in the louver created by the
hooked shape portion to define a continuous S-shape to eliminate
the eddy or stall created at the end of the circuitous path by the
hooked shape portion. Alternatively, the inlet can be enclosed by
the closeout to define an air pocket within the inlet. The closeout
can be penetrated by projectiles ricocheting through the circuitous
path such that the ballistic hook can capture the projectile within
the inlet.
[0009] A grille, according to an embodiment of the present
invention, comprises a plurality of S-shaped louvers arranged in an
overlapping configuration to define a plurality of circuitous paths
between the louvers through the grille. Each louver comprises a
hooked shaped portion at one end defining an inlet and a ballistic
hook generally perpendicular to the circuitous path. An insert
comprising a foam core can be positioned within an inlet. The
insert can be shaped to "fill in" the inlet to prevent the
ballistic hook from creating eddies or stalls as air flows through
the circuitous path. The insert can further comprise a closeout
comprising a material positioned over the foam core to provide a
continuous surface creating a smooth air flow. Alternatively, the
closeout can be positioned over the inlet with a foam core so as to
define an air pocket within the inlet.
[0010] In one aspect, a plurality of hardened bars can be
positioned in front of the louvers to fragment or degrade incoming
projectiles before the projectiles reach the louvers. Similarly, in
one aspect, an open honeycomb mesh can be positioned behind to
capture the remaining projectile fragments that ricochet through
circuitous path and are not captured by the ballistic hooks of the
louvers. In this aspect, the louvers can comprise a low weight
composite material to offset the increased weight from the bars and
mesh.
[0011] In one aspect, a method of preventing projectiles from
entering a vent comprising the steps of positioning a plurality of
S-shaped louvers in the vent, wherein each louver comprises a hook
shape portion defining an inlet and a ballistic hook oriented to
capture projectiles at one end of the louver. The method further
comprises arranging the S-shaped louvers in an overlapping
arrangement to define a plurality of circuitous routes between the
louvers for the passage of air through the vent. Finally, the
method comprises positioning an insert within the inlet to enclose
the ballistic hook to prevent disruption of the air flow through
the circuitous path, wherein the insert comprises a lower density
material than the louver such that the projectile can penetrate the
insert and be captured within by the ballistic hook.
[0012] The above summary of the various representative embodiments
of the invention is not intended to describe each illustrated
embodiment or every implementation of the invention. Rather, the
embodiments are chosen and described so that others skilled in the
art can appreciate and understand the principles and practices of
the invention. The figures in the detailed description that follow
more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE CLAIMS
[0013] The invention can be completely understood in consideration
of the following detailed description of various embodiments of the
invention in connection with the accompanying drawings, in
which:
[0014] FIG. 1 is a cross-sectional side view of a prior art grille
having a plurality of chevron shaped louvers.
[0015] FIG. 2 is a cross-sectional side view of a prior art grille
having a plurality of S-shaped louvers.
[0016] FIG. 3 is a cross-sectional side view of a prior art grille
having a plurality of S-shaped louvers each defining a hooked
portion.
[0017] FIG. 4 is a cross-sectional side view of a prior art grille
having a plurality of S-shaped louvers each defining a hooked
portion.
[0018] FIG. 5 is a cross-sectional side view of a prior art grille
having a plurality of S-shaped louvers each defining at least two
hooked portions.
[0019] FIG. 6 is a rear view of a representative vehicle having a
grille according to an embodiment of the present invention.
[0020] FIG. 7 is an exploded perspective view of a grille according
to an embodiment of the present invention.
[0021] FIG. 8 is a cross-sectional side view of a grille according
to an embodiment of the present invention.
[0022] FIG. 9 is a partial perspective view of an inner end of a
louver according to an embodiment of the present invention.
[0023] FIG. 10 is a representative cross-sectional side view of an
arrangement of louvers according to an embodiment of the present
invention illustrating the flow of air through the louvers.
[0024] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit the
invention to the particular embodiments described. On the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DETAILED DESCRIPTION
[0025] As shown in FIGS. 6-9, a grille 10, according to an
embodiment of the present invention, comprises a plurality of
S-shaped louvers 12 each having an exterior end 14 and an interior
end 16. In one aspect, the exterior end 14 can comprise a tapered
shape to minimize disruption of the airflow through the grille 10.
The interior end 16 further comprises a hooked portion 18 defining
an inlet 20 in the louver 12 and a ballistic hook 22 generally
perpendicular to the louver 12. Each louver 12 further comprises an
insert 22 shaped to fit within the inlet 20 and comprising a foam
core 24 and a closeout 26. In another aspect, the louver 12 can
only comprise the closeout 26 to define an air pocket in the inlet
20. In one aspect, the louvers can be about 3 inches long.
[0026] In one aspect, the louvers 12 can comprise a composite
material rather than a metal to reduce the overall weight of the
grille 10 while improving the ballistic protection of the grille
10. The composite material can capture projectiles with the same
effectiveness as steel or aluminum at a fraction of the weight. The
composite material can comprise a non-woven fibrous material
impregnated with a thermoplastic or thermoset resin matrix
material. In one aspect, the fibrous material can comprise aramid
(KEVLAR) or S2 glass fibers. In one aspect, the composite material
can comprise 60-80 wt % fibrous material and 20-40 wt % matrix
material. The composite material can formed by manufacturing
processes including, but not limited to, pultrusion, hand lay-up or
resin infusion methods.
[0027] Similarly, the foam core 24 can comprise a medium to high
density closed cell foam having a lower density than the composite
material used for the body of the louver 12. In one aspect, the
closeout 26 can comprise the same composite material as the body of
the louver 12.
[0028] As shown in FIGS. 8-10, the louvers 12 can be positioned in
parallel to define a plurality of circuitous paths between the
louvers 12. The exterior ends 14 of the louvers 12 are each
oriented toward the exterior of the vent into which the grille 10
while the interior ends 16 of the louvers are oriented toward the
vehicle compartment to be protected. The curved portions of the
louvers 12 are positioned in an overlapping arrangement such that
no linear path between the louvers 12 exists. In one aspect, the
louvers 12 can be positioned about 0.75 inches apart. In another
aspect, the louvers 12 are nested such that the flow path through
the grille 10 between the louvers 12 is about 50% of the
cross-sectional area of the grille 10. Projectiles travelling along
a generally linear path cannot navigate between the louvers 12
without contacting the louvers 12. The louvers 12 are shaped to
deflect or capture projectiles that contact the louver 12.
[0029] As shown in FIG. 10, air can navigate the circuitous path
between the louvers 12 and pass through the grille 10. The S-shaped
louver 12 provides a lower pressure drop across the louvers 12 than
other shapes. The closeout 26 presents a continuous airfoil along
the length of the louver 12 such that eddies or stalls does not
form at the end of the louver 12 as a result of the inlet 20 and
ballistic hook 22. The closeout 26 is sufficiently rigid to
maintain the continuous airfoil as the air travels between the
louvers 12. If a projectile is deflected down the circuitous path,
the lower density of the foam core 24 or the empty space of the air
pocket allow the thin closeout 26 to be penetrated by the
projectile such that the projectile enters the inlet 20 and is
captured by the ballistic hook 22.
[0030] As shown in FIG. 8, in one aspect, the grille 10 can further
comprise a plurality of hardened bars 28 in front of the exterior
ends 14 of the louvers 12. The hardened bars 28 can comprise a
hardened metal or other hardened material such that the bars 28 can
fragment or otherwise erode the projectiles before the projectiles
reach the louvers 12. In one aspect, the bars can be arranged in a
30 to 40 psf array.
[0031] As shown in FIG. 8, in one aspect, a honeycomb mesh 30 can
be positioned behind the interior ends 16 of the louvers 12. The
honeycomb mesh 30 can capture any remaining projectiles that
survive ricocheting through the circuitous paths. In particular,
the mesh 30 can act as a filter capturing small fragments of
projectiles that have broken up passing through the louvers 12. The
mesh 30 can be constructed of any lightweight material known in the
art such as aluminum, ceramic, plastic, carbon fiber, or composite
material.
[0032] In one aspect, the grille 10 can further comprise a frame 32
for simplifying installation of the grille 10. The louvers 12 and
mesh 30 can be pre-bonded to the frame 32, while the bars 28 can be
pre-welded to the frame 32 such that the entire frame 32 can be
installed into a vehicle 11 as a single unit as shown in FIG.
6.
[0033] The grille 10 can be affixed to a plurality of armored
vehicles 11 including, but not limited to tanks, infantry fighting
vehicles, armored cars or self-propelled artillery. As depicted in
FIG. 6, the grille 10 is installed over the air supply vents for
the engine of an M1A1 Abrams tank. The figure is intended to be
representative of the installation of the grille 10 and not
intended to be limiting with regards to the vehicle 11 on which the
grille 10 can be installed.
[0034] In one aspect of the present invention, a method of
preventing a projectile from entering a vent comprises positioning
a plurality of S-shaped louvers 12 in the vent, wherein each louver
12 defines an inlet 20 and a ballistic hook 22. The method further
comprises arranging the S-shaped louvers 12 in an overlapping
arrangement to define a plurality of circuitous paths between the
louvers 12 allowing air to flow through the vent while denying
projectiles a direct linear path through the vent. Finally, the
method comprises positioning an insert 22 within the inlet 20 to
cover the ballistic hook 22 and define a continuous s-shape along
the entire louver 12, wherein the insert 22 comprises a lower
density material than the louver 12 such that the projectile can
penetrate the insert 22 and be arrested by the ballistic hook
22.
[0035] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and described in detail. It is understood,
however, that the intention is not to limit the invention to the
particular embodiments described. On the contrary, the intention is
to cover all modifications, equivalents, and alternatives falling
within the spirit and scope of the invention as defined by the
appended claims.
* * * * *