U.S. patent application number 15/830436 was filed with the patent office on 2018-06-07 for ballistic curtain cordon system.
This patent application is currently assigned to Ballistic Cordon Systems, LLC. The applicant listed for this patent is Ballistic Cordon Systems, LLC. Invention is credited to Peter Lewis, Daniel Navin, James R. E. Ostman, Fen Tamulonis.
Application Number | 20180156577 15/830436 |
Document ID | / |
Family ID | 62240623 |
Filed Date | 2018-06-07 |
United States Patent
Application |
20180156577 |
Kind Code |
A1 |
Navin; Daniel ; et
al. |
June 7, 2018 |
Ballistic Curtain Cordon System
Abstract
A ballistic curtain system includes a curtain having cells
configured to stop a high-speed projectile and a motor connected to
the curtain. The motor is capable of deploying or retracting the
curtain.
Inventors: |
Navin; Daniel; (Stonington,
CT) ; Ostman; James R. E.; (Enola, PA) ;
Lewis; Peter; (Philadelphia, PA) ; Tamulonis;
Fen; (Media, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ballistic Cordon Systems, LLC |
Enola |
PA |
US |
|
|
Assignee: |
Ballistic Cordon Systems,
LLC
Enola
PA
|
Family ID: |
62240623 |
Appl. No.: |
15/830436 |
Filed: |
December 4, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62603866 |
Jun 14, 2017 |
|
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|
62497770 |
Dec 2, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F41H 5/023 20130101;
F41H 5/06 20130101; F41H 5/007 20130101 |
International
Class: |
F41H 5/007 20060101
F41H005/007; F41H 5/02 20060101 F41H005/02 |
Claims
1. A ballistic curtain system comprising: a curtain comprising
cells configured to stop a high-speed projectile; and a motor
connected to the curtain capable of deploying or retracting the
curtain.
2. The ballistic curtain system of claim 1, wherein the cells are
plates.
3. The ballistic curtain system of claim 2, wherein the cells are
contained within a fabric.
4. The ballistic curtain system of claim 3, wherein the fabric
comprises pockets, wherein each pocket comprises a plate.
5. The ballistic curtain system of claim 4, wherein the cells
overlap.
6. The ballistic curtain system of claim 4, wherein the cells
overlap to form a louvered arrangement.
7. The ballistic curtain system of claim 3, wherein the fabric
comprises a front side and a rear side.
8. The ballistic curtain system of claim 7, wherein the front side
and the rear side are attached to one another.
9. The ballistic curtain system of claim 3, wherein the curtain
comprises a fabric only portion and a fabric and cell portion,
wherein the fabric only portion comprises no cells.
10. The ballistic curtain system of claim 9 wherein the fabric only
portion is nearer to the motor than the fabric and cell
portion.
11. The ballistic curtain system of claim 1, wherein the motor
turns a driveshaft.
12. The ballistic curtain system of claim 11, wherein the
driveshaft turns a drum about which the curtain can wind and
unwind.
13. The ballistic curtain system of claim 1, wherein the system
comprises multiple curtains deployed in alternating
arrangement.
14. The ballistic curtain system of claim 1, further comprising a
controller that can be activated to control the motor.
15. The ballistic curtain system of claim 14, wherein the
controller can only be accessed by a user with a credential.
16. The ballistic curtain system of claim 1, wherein the curtain is
configured to deploy in an upward direction.
17. The ballistic curtain system of claim 1, wherein the curtain is
configured to deploy in a downward direction.
18. The ballistic curtain system of claim 1, wherein the curtain is
configured to deploy in a sidewise direction.
19. The ballistic curtain system of claim 1, wherein the deployment
of the curtain is done by allowing gravity to act on the
curtain.
20. A method of protecting an area comprising deploying a ballistic
curtain system comprising: a curtain comprising cells configured to
stop a high-speed projectile; and a motor connected to the curtain
capable of deploying or retracting the curtain, wherein the area
protected would be on an opposite side of the curtain from a
threat.
Description
BACKGROUND
[0001] Mass shootings make headlines with regularity. The worst of
those shootings often take place in confined areas like schools or
offices.
[0002] Most solutions aimed at preventing mass shootings by an
already-armed assailant are based on firearm detection or denial of
entry to the building in the first place. Firearm detection
includes installation of metal detectors and similar devices around
entry points to a building. The problem with these solutions is
that they do not prevent entry or slow an active shooter--they
merely provide a potential alarm that a motivated shooter has
entered a facility, denying entry to a shooter may involve armed
guards, airlock dual entry systems, or use of technology-based
credentials to afford entry. But even with these solutions, a
motivated shooter can gain entry to a facility. This was the case
in the Washington Navy Yard shooting in 2013 and the Fort Hood
shooting in 2009. Likewise, in the case of the Sandy Hook
Elementary School shooting, the shooter was able to defeat the
entry denial system by simply shooting his way through a glass
panel.
[0003] There may be no foolproof way to deny a determined shooter
from entering a building. Some buildings now post active shooter
plans, similar to fire escape routes, in an effort to inform
occupants the best actions to take in an active shooter scenario.
These plans remain often ineffective because channeling people
through choke points in halls or stairwells only gathers more
potential victims in one place.
[0004] A need thus exists to provide building occupants with a way
of protecting themselves, exiting a building, and if not fully
preventing casualties inflicted by a mass shooter, at least
minimizing such casualties.
SUMMARY OF THE EMBODIMENTS
[0005] A ballistic curtain system includes a curtain having cells
configured to stop a high-speed projectile and a motor connected to
the curtain (or other force to deploy the curtain as needed). The
curtain should be capable of being deployed and retracted,
optionally at selected speeds, based upon the direction of
deployment--such as sidewise, upwardly, or downwardly--as well as
the area to be protected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIGS. 1A and 1B show an overview of a before and after
situation using the ballistic curtain system described herein.
[0007] FIGS. 2A and 2B show an overview of a before and after
situation using the ballistic curtain system described herein in an
alternate configuration.
[0008] FIGS. 3A and 3B show an overview of a before and after
situation using the ballistic curtain system described herein in an
alternate configuration.
[0009] FIG. 4 shows a single deployed ballistic curtain system.
[0010] FIG. 5 shows a sample cell layout
[0011] FIG. 6 shows use of cell material to envelop each cell to
create the louvre arrangement of the curtain FIG. 5).
[0012] FIG. 7 shows a graphical depiction of the motor.
[0013] FIG. 8 shows a wiring schematic of the motor.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] 1. Introduction
[0015] FIGS. 1A and 1B show an overview of a before and after
situation using the ballistic curtain system described herein. FIG.
1A shows an active shooter 90 with a clear view of victims 95 down
a corridor. In such a situation without the ballistic curtain
system, the shooter may be able to harm not only the visible
victims 95, but also those who may enter the corridor hoping to
exit the building according to an evacuation plan. The shooter 90
also has the ability to move quickly down the corridor
unobstructed.
[0016] FIG. 2A shows a similar situation in which an active shooter
90 has entered a confined area with many potential victims 95. In
this situation, the shooter 90's victims 95 are clustered in a
small area and the shooter 90 need move into the room no further
than the doorway to inflict harm.
[0017] FIG. 3A shows an alternate situation in an outdoor concert
or other open venue 300.
[0018] FIGS. 1B, 2B, and 3B show the same corridor, room, and open
venue but with the ballistic curtain 100 deployed. The ballistic
curtain system 100, described in greater detail below, deploys to
prevent the shooter 90 from having free access to harm victims 95.
The silhouettes 97 in FIGS. 1B and 2B show potential victims who
are safe behind a bullet absorbing/blocking/slowing curtain 100. In
the corridor scenario in FIG. 1B, these potential victims 95 can
egress down the corridor between alternating extended curtains 100a
and 100b, which prevent the shooter 90 from having a command
position controlling the corridor. The curtains 100 interrupt the
shooter 90's visual and physical continuum without preventing
potential victims 95 from freely escaping from the area, preferably
without significantly slowing down a potential victim 95 from
fleeing the scene.
[0019] In the confined area scenario shown in FIG. 2B, the shooter
90 will have to move from the doorway into the room, and try to
access the space behind the curtain. This will not only take time
in which authorities may arrive, but also put the shooter 90 at
risk of attack, and both circumstances may result in fewer or no
casualties. In this "safe corner" configuration, the curtain may
optionally be secured to the floor and/or side tracks, like a
garage door, which convert the curtain from a free hanging design
to a barrier which would take time and effort to overcome.
[0020] In the open venue 300 in FIGS. 3A and 3B, the curtains 100
extend upwards and deploy to provide multiple sheltered zones that
allow potential victims to seek shelter and escape. This upwards
deployment may be accomplished using a scissor-lift, wherein the
curtain 100 is deployed as the lift raises a terminal end of the
curtain in order to raise the curtain.
[0021] Although it is not shown, the curtain could also be deployed
horizontally, so that it provided a "roof" like shelter.
[0022] The deployment of the ballistic curtain 100 could be manual
or mechanical, gravity driven, or based on systems of
counterweights or draw chains like an old-fashioned screen. But
more likely, the ballistic curtains would deploy using
electrotechnical motors in communication with an alarm system that
might be automatically activated in response to sound detection
indicative of gunfire or explosions, or someone manually activating
the system either from within the building like a fire alarm, or
remotely from a central location or by authorities.
[0023] The ballistic curtain 100 may contain sensors capable of
sending feedback to authorities when it registers an impact
indicative of a bullet or high-speed projectile. This may help
authorities in quickly locating the active shooter, and could also
help building occupants make a safe exit if they know where the
shooter is. Technology in the building could direct occupants away
from the area where the shooter is active, for example.
[0024] While the figures and discussion show and describe a
ceiling-mounted ballistic curtain that hangs and rolls, this is not
meant to be limiting from ballistic curtains that are wall- or
floor-mounted, partially or fully rigid, or that are folded or in
sheets. As will be appreciated, the curtain 100 may be deployed in
any direction, which can readily be selected based upon the
location and geometry of installation. For instance, in some
situations it may useful to use curtains that when not deployed are
at floor-level and deploy upward (such as in outdoor or temporary
venues, including stadiums, arenas and the like) while in other
situations it may be preferable to utilize curtains that are along
the wall when not deployed and deploy inwardly (such as may be
useful when ceiling height or other factors make a downward
deployment or ceiling mounting impractical).
[0025] 2. Design Goals
[0026] An embodiment of the ballistic curtain system is a storable,
armored partition that can be affixed to a ceiling or ground and be
unrolled upon activation. The curtain should be capable of stopping
or deflecting rifle bullets commonly used in mass shooting attacks,
up to and including the 7.62.times.51 mm NATO round. In addition to
being deployable upon user activation, the system should also be
retractable at the discretion of first responders. In order to
facilitate this, a motor and electronic control system may be
incorporated into the system.
[0027] Testing and evaluation have identified certain needs and
specifications, which are non-limiting. Table 1 summarizes these as
used in one example of a prototype (and therefore the values are
meant to inform but not be limiting).
TABLE-US-00001 TABLE 1.1 Stakeholder needs Need Metric
Specification Ability to stop Level (Standard Level 8 & Shotgun
(UL 752) projectiles org) Level III A (NIJ 018.01) 7.62 NATO/Rifle
(ASTM F- 1233) Level D (HPW-TP 0500.02) [9] Deployment seconds 3,
in a standard 9-10-foot hallway time Number of impacts At least 3
shots in a given target Toughness area with the highest rated rifle
round, from 5 feet away or meet NIJ standards listed below
Reusability -- Unused curtains should be able to be to stowed in
their housings with minimal effort Replaceability -- Used curtains
should be repaired/replaceable with minimum downtime Retractability
yes/no Yes, can be retracted by authorized user (SWAT request)
Systems Number of systems Two main electrical systems: needed Motor
system and network system Networking Should Arduino Ethernet shield
or Wi-Fi communicate shield could be used Integration Should work
with Device will integrate to existing infrastructure emergency
response technologies (Alarm systems, PA, etc.)
[0028] 3. Design Description
[0029] 3.1. Specifications
[0030] The UL 752 standard is widely used in industry and gauges
the requirements for "cover materials, devices, and fixtures used
to form bullet-resisting barriers which protect against robbery,
holdup, or armed attack such as those by snipers." The National
Institute of Justice (NU) standards for ballistic resistance
"establish minimum performance requirements and test methods for
the ballistic resistance of personal body armor intended to protect
against gunfire." Other standards may be followed including those
related to local, state and federal fire codes, building codes and
relevant Department of Defense (DOD) and Homeland Security
procedures (all of these are constantly being revised and so we do
not seek to summarize them since they are constantly evolving).
[0031] 3.2. Ballistic Curtain System Design Overview
[0032] FIG. 4 shows a single deployed ballistic curtain system 100,
in one example of a ceiling-deploy orientation (ceiling mounts are
adaptable to the needs of a selected location). That example
includes a deployable and retractable partition of a curtain 110
that will stop pistol, rifle and shotgun rounds from penetrating
it. The curtain 110 is deployable in any direction as mentioned
above and its materials may include a cut-resistant outer fabric
120 surrounding a core 130 that may be made from hardened steel
armor. The outer fabric 120 may include 1050D ballistic nylon
although other load bearing materials or another substrate material
can be used. In use, the fabric 120 may support the steel armor
core 130 or not be included. It should be appreciated in FIG. 4
that the fabric 120 is shown cut away to show the core 130, for
illustration purposes. An electric motor 140 mounted on a frame 150
or other suitable load-bearing structure, deploys each steel
curtain 100 and may be configured to operate multiple steel
curtains 100 for deployment at once.
[0033] 3.2.1. Curtain with Cells
[0034] FIG. 5 shows an overview of the core 130. The hardened steel
cells 132 that make up the ballistic core 130 serve to stop rifle
bullets. Using AR500 steel for the cell 132 material was based on
its use in marksmanship training with targets comprised of the same
material. AR500 targets may stand up to hundreds of impacts from
high powered rifles, even with a thickness of just 1/4 inch. Thus,
AR500 may meet the requirement of being capable of stopping rifle
rounds, while maintaining a slim cell design that could be rolled
tightly as a curtain. Although AR500 may be presently preferred, it
is not meant to be non-limiting.
[0035] The steel cells 132 may be rectangular in shape and measure
8 inches long, by 2 inches wide by 1/4 inch thick for most
deployment, with this sizing being capable of deployment and
manufacture, although it will be appreciated that other cell
designs may be used such cells that are as long as the curtain is
wide (e.g., a curtain that is 36'' wide would have cells measuring
36.times.2.times.1/4). The cells 132 may be laser cut to this
shape. Specific cell sizes may vary as manufacturing and
installation design decisions are made.
[0036] The steel cells 132 may be mechanically linked to one
another to create a fixed louvered arrangement using welding or
other mechanical linkage. But what is shown in FIG. 5 is a way of
using the material 120 to envelop each cell 132 to create the
louvred overlap of each cell 132. There may be metallic mechanical
linkages between cells but this can be varied based upon
manufacturing and installation design choices.
[0037] FIG. 6 shows the fabric 120 having a front side 122 and rear
side 124 (which sides could be reversed or interchangeable, the
terms front and rear having no meaning besides in the context of
the left side of the figure being arbitrarily called the "front").
The rear side fabric 124 may be generally flat and featureless. The
front side fabric 122, however, may include pockets 126
appropriately sized to receive each cell 132, which may rest inside
the pockets 126 or be bonded, attached mechanically, or removably
attached using hook and loop material on each of the cell 132 and
pocket 126. Although this "pocket" configuration is shown, other
designs may provide a deployable curtain.
[0038] The front side 122 and rear side 124 may be bonded to one
another using stitching, adhesives, or other bonding means capable
of providing structure for the pockets 126 and bonding the sides
together.
[0039] Although the rectangular shape of cells 123 has been shown
and described other cell shapes such as hexagonal may be preferred
as they may permit a smaller radius to the curtain 110 when in a
stored or undeployed state, although such shapes may be more
expensive to manufacture and more difficult to deploy in a louvered
arrangement.
[0040] The curtain material may be chosen based upon performance
characteristics and manufacturing design decisions, but 1050D
ballistic nylon is preferred because of its properties s having
sufficient resistance to the forces exerted upon the material
during normal operation. With an effective tensile strength of
approximately 1,000 lbs and a burst pressure resistance exceeding
1500 psi the material can resist both the weight of the steel
hanging on it as well as resting broad tearing and destruction
associated with the steel cells being impacted by a bullet.
[0041] In furtherance of weight savings, the entire length of the
curtain 110 may be limited in its inclusion of cells 132, meaning
that as shown in FIG. 4, the curtain may include a fabric only
portion 115 and a fabric and cell portion 117 (the fabric and cell
portion shown in FIG. 4 has the material cutaway, but FIG. 6 shows
the fabric and cell portion 117 more clearly). The material and
cell portion 117 may be expanded or contracted based on the need
and placement in order to provide vital coverage of human
dimensions. In a normal hallway or one level room environment, in
one option the fabric and cell portion 117 may not extend higher
than 6' from the floor and 6'' from the floor. This bifurcated form
of construction allows for visual interruption throughout the
entire length of the partition as well as optimal weight,
pliability and energy dissipation.
[0042] 3.2.2. Material Details [0043] AR500 Steel
[0044] AR500 (Abrasion resistant, Brinell hardness of 500)
steel-AR500 is an abrasion resistant high carbon steel. Its
hardness and abrasion resistant qualities make it an excellent
ballistic material.
[0045] Tables 2 and 3 summarize its composition and properties.
TABLE-US-00002 TABLE 2 Composition of AR500 Steel Element %
composition Carbon 0.31 Manganese 1.50 Phosphorus 0.025 Silicon
0.50 Chromium 0.87 Nickel 0.70 Molybdenum 0.35 Boron 0.003 Sulfur
0.015
TABLE-US-00003 TABLE 3 Material Properties Property Value Yield
Strength 200 ksi Tensile Strength 225 ksi Brinell Hardness 477-550
(500)-Core 450 min. Elongation 12% (in 2'') Impact Strength CVNL
~20 ft @-40 F.
[0046] Anti Spall Coating
[0047] One of the greatest threats from a ballistic attack comes
from spalling or explosion of metal fragments. Anti-spall coatings
may be sprayed over the cells 132, which will encapsulate bullets
and other ballistic objects, remaining intact, without posing
further secondary damage resulting from spalling and fragmentation.
[0048] Kevlar
[0049] The fabric material may be made from Kevlar, a synthetic
fiber made by DuPont having the chemical formula:
[--CO-C6H4-CO--NH-C6H4-NH-] n
[0050] 3.3. Motor System
[0051] When ascertaining the specification for a motor 140 to
deploy and store the curtain 110, torque is a parameter that is
usually measured in oz-in. An as-tested, ceiling-deployed model
yielded the following results.
TABLE-US-00004 TABLE 4 Parameters converted to motor specification
units Metric Lighter Heavier Weight (lbs) .fwdarw. Mass (oz-in/
2.0704 4.141 sec{circumflex over ( )}2) Target Speed (Curtain going
1 1 up) (ft/sec) Motor Gear ratio 6 6 Curtain Roll Radius (inches)
3.72 3.72
[0052] Assuming correct units, the inertia of the curtain (Jr),
motor (Jm) and total inertia (Jeq) were calculated using a MATLAB
script. The first step in calculating the torque was to calculate
inertia pertaining to two main systems: the curtain roller (Jr) and
the motor (Jm). After the two results of inertia were found, the
total inertia of the system was calculated and translated through
the gear ratio. This final inertia (Jeq) was the inertia used in
order to determine the final torque calculation.
[0053] Subsequent to determining the inertia of the system, angular
acceleration was to be ascertained. In order to calculate this
specification, a benchmark test speed for raising the curtain was
selected. Since the input voltage pattern was known, the angular
acceleration could be calculated in rads/sec.
[0054] Utilizing angular acceleration and total inertia, both known
at this point, the torque at the rotor (Tr) could be calculated.
Translating this torque through the gear ratio gave the final
torque measurement of the motor (Tm). However, this is the peak
torque seen by the motor during normal operation and only occurs
for a small amount of operating time. Since the motor may be
operating for at least 10 secs during a lift, the continuous
torque, or RMS torque of the motor, was required (Trms). Table 5
depicts the final values of RMS torque, speed, and inertia that the
motor had to meet.
TABLE-US-00005 TABLE 5 Final motor parameters based on torque
calculations and updated weight RMS torque or rated torque Weight
of curtain (Ibs) (oz-in) Total inertia 100 307.1 59.17
[0055] These calculations provided a reliable estimate regarding
the size of the motor needed. A brush DC motor may be used to allow
for easier speed and position control. Additionally, DC motors are
markedly less expensive than DC brushless motors and stepper
motors. A tertiary reason for selecting a brushed DC motor was
lacking any need for precision control pertaining to the position
of the rotor. This is simply because the only positions that were
relevant were fully lowered or fully retracted.
[0056] FIG. 7 shows a graphical depiction of the motor 140
described herein, showing a driveshaft 142 and winding drum 144,
which is attached to the curtain 110 and about which the curtain
110 winds and unwinds. An electromechanical brake system may be
activated during lowering the curtain to allow for rapid and safe
deployment. This system may work using an active low principle;
meaning that the brake's force is applied to the motor's driveshaft
when no voltage is applied. Once voltage is applied to the brake,
it releases and the curtain drops. Reiteratively, torque
calculations were done to size the brake in probable terms. Since
the brake is the only device restraining the descent of the
curtain, a peak torque estimation was used instead of an RMS
torque. This was to allow for error approximation as well as a
safety factor.
[0057] FIG. 8 shows a wiring diagram of the control system for the
motor having a as components the motor 140, motor relay 145, motor
controller 146, Arduino 147, brake 148, brake relay 149 and voltage
source 143. The brake 148 may have an operating voltage of 24 volts
and the motor 140 may have a max voltage of 24 volts. A single
24-volt supply 143 may be split and fed into the brake relay 149
and motor controller 146. Relays may be used to ensure that voltage
is applied only when requested and also to prevent back EMF from
the motor 140 causing over voltage issues in the rest of the
circuit when the curtain 100 is deployed. An Arduino 147 may be
used to control the speed and direction of motor 140 as well as
when the brake 148 is applied.
[0058] In a networked or connected ballistic curtain system, a
control system may ensure that only authorized users can deploy the
curtain 110. The control system may be accessed by only authorized
users, who may gain access using a credential such as passwords,
fobs, retinal scans or other secure access, and those users may
access the control system to deploy or retract the curtain(s) in
total, one at a time, or in only some areas. The access may also
allow a user to see what curtains have been or are being
damaged.
[0059] 4. Testing
[0060] 4.1. Analytical Testing
[0061] A prototype testing plan encompassed two phases. The first
phase entailed analytical testing of models using multi-physics
simulation software like ANSYS workbench and FEA methods similar to
those available in Creo. This allowed the tester to analyze the
model as much as possible in a virtual setting before completing a
design. Emphasis was centered on the analysis of forces exerted on
the structural components of the BCCS in order to ensure that they
could withstand the force of gravity while in free hanging mode, as
well as the dispersed energy of ballistic impacts.
[0062] An ANSYS "Explicit Dynamics" project was generated in order
to reflect a single projectile impact and simulate realistic
material behavior of the system. Within the ANSYS environment the
model was refined to reflect explicit materials. The ANSYS library
did not have an AR-500 steel offering as an available material.
Therefore, another steel compound (Steel-4340) was modified to
reflect the proper material values in order to emulate AR-500
steel. The simulated bullet represented a pure copper round due to
computational limitations.
[0063] Two bullet impacts were separately simulated. Each
simulation conformed to the NIJ standards for armor testing. The
initial impact, representing the "low" end of the standards scale,
was a 9 mm parabellum Luger Full Metal Jacket (FMJ). The secondary
impact, representing the "high" end of the standard scale, was a
7.62 mm (.308 caliber) FMJ NATO round. Both rounds were fired from
several centimeters away from the plate at 373 and 847 m/s
respectively [11] per NIJ standards. From these impacts, the
acceleration of the front face and back face of the plate was
probed. The data from the acceleration probes was plotted in ANYS.
Through analysis, the relevant acceleration and time steps were
extracted.
[0064] A simplified model of the curtain was produced in MSC ADAMS,
a multibody dynamics simulation software, in order to simulate the
effect of an impact over the entire curtain. The acceleration data
from the ANSYS tests was incorporated in the ADAMS model test by
using a step function to supply a force. This produced calculated
acceleration results over its time step interval, as evidenced from
the acceleration graphical data. This force was applied at the
center of the curtain allowing the dynamic simulation to exhibit
the force reactions within the curtain. Throughout the ADAMS
simulation, the top, middle and bottom plates were probed in order
to analyze the dynamic response of the curtain to impact. This data
is relevant for the addition of a possible added feature of the
BCCS, which can help locate the shooter, as the data is
characteristic to which side of the curtain the gunshots are
originating.
[0065] 4.2. Physical Testing
[0066] The second phase entailed physical testing. This process
involved subjecting a functional prototype to ballistic impact
tests, as well as subjecting a non-ballistic prototype to
deployment and roll-ability tests.
[0067] 4.2.1. Ballistic Testing
[0068] The ballistic tests were conducted on the prototype. For
this testing, a ballistic curtain measuring 2 ft.times.2 ft was
suspended from wooden frame allowing feasible replication of full
deployment. Approximately 1 ft behind the curtain, a backdrop of
contractor's paper was spanned across the area of the curtain.
Ballistic penetration, residual debris or fragmentation would be
evidenced upon the backdrop. Cameras were positioned forward of,
and adjacent to, the target area in order to film the terminal
ballistic effects upon the curtain.
[0069] Safety was a vital consideration for the ballistic testing
phase. Primary concerns included ricochet and fragmentation.
Secondary concerns related to hearing protection and collateral
property damage.
[0070] From a range of 25 meters, various rifle calibers were fired
at specific points on the curtain. The first cartridge to be tested
was the 7.62.times.51 mm NATO round as this was the largest
anticipated ammunition round within our design parameters. At the
conclusion of two test fires, the first round made impact at the
convergence of two plate edges. The bullet damaged both plates and
was able to pass through. However, the bullet had fragmented upon
impact, as evidenced from the paper backdrop. The second round
struck a plate center mass and cleanly penetrated through the
armor. A thicker armor could stop this round in theory but this was
not evaluated.
[0071] The second phase of testing entailed a 5.56 mm, 55 grain,
"green tip" NATO round. This commonly used and acquired caliber
within the U.S. It is utilized within a diverse range of firearm
platforms to include the widely popular semi-automatic AR-15 rifle
and variants. Despite several rounds of test fire, this load and
caliber bullet was unable to penetrate the steel plate. Residual
evidence of bullet strikes included impact craters and scarring,
but lacked complete perforation. Impacts upon the convergence of
plates did not evidence bullet puncture, although there was trace
evidence of spall passing through.
[0072] Finally, pistol rounds of 9 mm and .45 caliber were fired at
the curtain from a range of 10 meters. As expected, these rounds
had essentially no effect on the steel and were unable to pass
through the curtain. Damage to the hook and loop material that
holds the cells in place did occur on the impact side of the
curtain. However, as the cells are held in place from both sides
with hook and loop, the non-impacted side remained undamaged, thus
the steel cells remained securely in place. This remained true even
for cells that experienced 3 direct hits.
[0073] While the invention has been described with reference to the
embodiments above, a person of ordinary skill in the art would
understand that various changes or modifications may be made
thereto without departing from the scope of the claims.
* * * * *