Charles V. WARREN --- DropMaster CopterBox Deivery System --
2 articles & 2 patents

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**Charles WARREN**

**DropMaster Delivery System**



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[**http://www.military.com/soldiertech/0,14632,Soldiertech\_CopterBox,,00.html**](http://www.military.com/soldiertech/0,14632,Soldiertech_CopterBox,,00.html)

*For troops in the field, replenishing supplies can be the
biggest hurdle of them all -- a hurdle which may disappear
with the help of the new*

***CopterBox Delivery System.***

**By David Crane**   
**Editor, DefenseReview.com**

Hypothetical Scenario: A U.S. military Special Operations team
is currently in the middle of a clandestine op, in-theater.
They're running low on 5.56x45mm and 7.62x51mm ammo, magazines,
40mm grenades, food, and medical supplies. One of the team's
SOPMOD M4/M4A1 Carbines is down, and they need two extra HK69A1
40mm grenade launchers and a Milkor MGL Mk-1S as force
multipliers. As if that's not enough, the local warlord who's
been assisting the team against enemy insurgents is now asking
for another $500,000 U.S. and a brand new stainless steel Rolex
Submariner wristwatch, just like the one he's seen on the wrist
of one of the operators.

DefenseReview.com (DefRev) is an online tactical technology
magazine that focuses on advanced tactical armament, tactical
equipment/gear (including combat/tactical camouflage
technology), and tactical training/instruction for military
infantry forces. DefenseReview.com strives to provide the most
up-to-date information on law enforcement (LE) SWAT/SRT and
military Special Operations (infantry)/Special Warfare (SPECWAR)
technology developments as quickly as we learn about them.

This team needs a little care package delivered, fast and
low-profile. So, they call it in. Five hours later, as the team
hangs tight under tree cover, four hexagonal corrugated paper
boxes are airdropped from a non-descript utility aircraft at 300
feet. Four low-signature airdrop bundles exit the aircraft.
Pilot chutes and rotor blades on all four deploy, which allow
them to autorotate down to the ground accurately at less than 40
feet per second. As the containers hit the tree line, the rotor
blades slice right through the tree canopy at 400 rpm. The team
recovers the payload and extracts the requested goodies. They're
back in business, and back in the game.

The airdrop scenario described above is now possible because
some creative thinkers at DropMaster, Inc. have come up with
CopterBox, an item so simple in concept and design that it's
easy to overlook its potential to profoundly change the U.S.
military's resupply doctrine and logistics paradigm.

**Airdrop It and Forget It**

The result of a privately funded 9-year, $450,000 project,
CopterBox is an expendable airdrop delivery system specifically
designed to deliver a 60-100 lb payload anywhere in the world,
anytime it's needed. With CopterBox, you don't need specially
trained riggers to rig Mil-Spec cargo parachutes and 200 lb
(minimum) pallets for a 60-100 lb payload. And, you don't need a
C-17 Globemaster III or C-130 Hercules tactical transport
aircraft to airdrop it, or a CH-47D/MH47E Chinook heavy lift
helicopter or UH1-Y Huey utility helicopter to land with it. All
you need is a single non-specialized soldier to quick-assemble
CopterBox, fill it up with the needed supplies, and load it onto
any military or civilian aircraft that will hold it. Then, just
airdrop it and forget about it. Once it's safely on the ground,
a single operator can quickly recover the payload and dispose of
the empty system, then get right back to the mission. Quick and
easy. Four CopterBoxes dropped means four operators to recover
them, and so on.

**CopterBox: The Skinny**

Name:   
DropMaster CopterBox

Type of Equipment:   
Airdrop delivery system

Killer Features:

\* Can deliver between 60-100 pounds of payload, anywhere,
anytime   
\* Can be airdropped from any aircraft or helicopter   
\* Delivery accuracy outshines standard parachute-dropped
supplies   
\* At $300 per CopterBox, a clear savings compared to standard
cargo delivery systems

MP3 File - British Forces Broadcasting Service (BFBS) interview
with Chase Warren, DropMaster Inc.'s Director of Engineering

For more information about CopterBox, or to place an order for
it, contact DropMaster, Inc. at 910-630-3269, or by email at
copterbox@dropmaster.com

With the U.S. military's current parachute-based system, an
open-field airdrop is usually the best way to go, since the
chutes and lines can get hung up in the trees. But, an
open-field recovery exposes the team. Aside from the rigging and
delivery logistics problems, payload recovery with this system
can also be physically difficult and time-consuming. A helo drop
requires said helo to either hover over the drop zone or land
with the risk of airborne sand brownout or foliage-related
foreign object damage, plus the added danger of enemy attention.
Helicopter flight time spent hovering and landing is very
expensive, as is losing the aircraft to hostile fire.

Fortunately, at only $300 per unit, CopterBox makes all this
unnecessary. It's even more accurate than parachute-based
systems, since wind drift hardly effects its trajectory. The
CopterBox's impressive delivery accuracy/minimal wind drift has
already been observed in prototype testing from 200 to 10,000
feet above ground level.

And, here's the kicker: with additional developmental funding,
CopterBox can be outfitted with a low-drag cardboard fairing and
hard points for UAV (or other aircraft) deployment. The
CopterBox can also be constructed out of inexpensive corrugated
plastic sheet for water-resistance or re-use, per organizational
requirement and development funding. Another potential
operational benefit is the ability to attach an altimeter or
timer delay device to the pilot chute deployment system,
allowing CopterBox to be free-dropped from high altitude out of
small arms fire reach without the associated long drift time. A
larger diameter or taller CopterBox can also be developed with
additional funding, and can be scaled to customer/end-user
requirements. For instance, a small arms/light weapons-specific
version of Copterbox can be developed that will allow delivery
of small arms and light weapons to the field, fully assembled.
The weapons can be arranged concentrically with internal
spacers, to prevent damage. Other versions can be developed to
deliver replacement Javelin anti-armor missiles and Predator
short-range assault weapons.

The Rotor Blade Deployment Sequence

When CopterBox is deployed from the aircraft, the small drogue
chute comes out first. The drogue chute, utilizing mesh in lieu
of shroud lines (to prevent tangling and snagging on foliage),
orients CopterBox into the relative wind. The chute pulls on the
drogue line. This causes a patented break-away stitching system
to force a delayed deployment (i.e. opening) of the rotor
blades, once CopterBox is safely away from the aircraft. The
break-away stitching system also ensures reliable rotor blade
deployment.

Once the rotor blades are deployed, they cause CopterBox to
spin at 400 rpm and begin the autorotative descent to the target
area on the ground, and enable it to cut right through dense
foliage on its way down. An added benefit of CopterBox's drogue
chute/orientation system is that it negates payload
center-of-gravity issues when it's packed and loaded onto the
aircraft. It also makes CopterBox easy to locate, since you can
color the drogue chute any way you like--even hot pink! Once you
recover it, just stuff the brightly colored chute back inside
CopterBox.

During touchdown, a paper honeycomb shock absorber plug
protects the payload from impact damage. This custom-made
honeycomb is tailored to crush from the deceleration of 60 to
100 lbs, unlike the much stiffer Mil-Spec material, which is
designed for much heavier payloads. A welded wire rotor hub is
at the top of the box, which withstands all of the rotor blade
flight and centrifugal loads. The same part is used on the
bottom as a landing skid, which protects the box during rigging,
shifting around in the aircraft and upon ground impact. After
landing, these two items can be used as camp stoves if needed.

So, what's the word on the proverbial street about CopterBox?
Word is, to a man, every U.S. military spec-operator who's seen
the CopterBox prototype demonstrated is very excited about it,
and wants it operational ASAP. PSYOPS personnel are excited
about CopterBox's ability to be modified into a psychological
warfare tool. CopterBox can be easily and inexpensively modified
into a propaganda leaflet dispenser by including centrifugally
opened panels on the hexagonal sides, triggered by the
aforementioned timer or altimeter. So, as CopterBox spins, the
leaflets spin right out, go everywhere, and accurately reach the
intended population.

**CopterBox Kit**

Simplicity itself: The CopterBox kit.

Unfortunately, U.S. military brass have allegedly been dragging
their heels on adopting CopterBox. One of the speculated reasons
is that CopterBox's extremely low $300 per unit price makes it
administratively unattractive, and less of a "larger-ticket
item." What should be stressed is that CopterBox is useful and
adaptable, and has the potential to become a major program from
sheer deployment numbers. As one considers the price of a
CopterBox versus the astronomical expense of reusable cargo
parachutes (that likely do not get reused) and all of their
associated logistical costs, CopterBox's budgetary benefits
quickly become clear. It's the author's opinion that our Special
Operations personnel need CopterBox, or something like it, right
now. So do our U.S. Army and Marine Corps general infantry, for
that matter. Non-military applications also come to mind, such
as humanitarian relief, domestic disaster relief, and the Forest
Service's Smokejumpers.

**Dimensions and Specifications:**

In its rectangular kit form, which comes in a plastic bag to
protect it from the elements, CopterBox occupies a 9" X 18" X
34" space on a shelf or pallet. In its rigged, hexagonal form,
it is 34" tall and fits inside an 18" circle. The current
product, the model 6036, is designed to hold 60 lbs and 3.6
cubic feet of payload while fitting out of a Cessna 172 test
aircraft's door. Although it is designed for 60 lbs, it can
handle up to 100 lbs -- albeit at the expense of a higher
descent rate, and the ability for a single person to load it
into an aircraft and for one operator to easily handle it on the
ground. With minimal training and the instruction sheet
provided, one person can assemble a loaded CopterBox in about 5
minutes. The instruction sheet has received real world end-user
input to maximize clarity and ease of assembly. The patented
rotor blades are constructed from high-strength corrugated paper
but are folded in a way that provide a high degree of strength
and aerodynamic lift. A yardstick-type spar is added for
additional strength, as there is an incredible amount of
aerodynamic stress on the blades during the deployment and
flight sequences.

It should also be noted that DropMaster, Inc. received a 98%
rating by the U.S. Army Soldier Systems Center (Natick), on
their Phase I efforts on a Small Business Innovation Research
(SBIR) grant. DropMaster, Inc. was also invited by Natick to
participate in a Phase II grant, two years in a row. However,
military funding obstacles have since intervened.

About the Author: David Crane is a military defense industry
analyst and consultant, and the owner/editor-in-chief of
DefenseReview.com. He can be contacted by phone at 305-389-1721,
or via email at david@defensereview.com.

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[**http://www.acq.osd.mil/osbp/sbir/overview/index.htm**](http://www.acq.osd.mil/osbp/sbir/overview/index.htm)

**CopterBox Expendable Airdrop Delivery System for Ammo,
Food, Meds, and More**

**by David Crane**   
**david@defensereview.com**

DropMaster, Inc. has developed a new, expendable airdrop
delivery system, called CopterBox. CopterBox is an autorotating,
disposable aerial resupply system, and appears to be a
superlative, off-the-shelf product. It is specifically designed
to be quick to assemble with minimal training, easy to deploy
with or without a static line and to be lightweight for a single
operator to recover on the ground.

When dropped from an aircraft, CopterBox decelerates a 60 lb
payload to about 34 feet per second at sea level. DropMaster's
main focus is simplicity and low cost. Since CopterBox is meant
to be expendable (it's predominantly biodegradable and/or
burnable), you can just drop it and forget it. A patented pilot
chute delay system allows CopterBox to fall a safe distance away
from an aircraft prior to rotor blade deployment.

After the rotor blades deploy and autorotation begins, the
steady-state descent is not affected much by wind drift, unlike
parachute-based systems. This minimal wind drift has been
observed in prototype testing from 200 to 1,500 feet, resulting
in tremendous delivery accuracy. And, because it spins at about
400 RPM, CopterBox cuts through trees and always reaches the
ground, again, unlike... parachute-based systems. It is
primarily made of high-strength corrugated paper (high-strength
cardboard) with minimal metal and nylon parts. These simple
materials allow CopterBox to be scalable to customer needs.

With minimal additional cost, a low-drag cardboard fairing can
be fitted along with hard points for deployment from UAVs or
other aircraft. Pending proper funding, GPS guidance can be
achieved for HALO drops where guidance occurs prior to
altimeter-triggered rotor blade deployment at a pre-set
altitude. CopterBox requires no logistical support or
maintenance.

Payload weight is currently limited to 60 to 100 lbs. This
allows a single operator to recover the payload and easily
dispose of the empty system, so he can quickly carry on with his
mission.

If necessary, CopterBox can easily be made from high-strength
corrugated plastic sheet (instead of high-strength
paper/cardboard), in order to be water-resistant.

Priced at $300 per unit, CopterBox is patented and is the
result of a nine year, $450,000 project. It should also be noted
that DropMaster, Inc. received a 98% rating by the U.S. Army
Natick Soldier Center, a.k.a. U.S. Army Soldier Systems Center
(Natick), on their Phase I efforts on a Small Business
Innovation Research (SBIR) grant. DropMaster, Inc. was also
invited by Natick to participate in a Phase II grant, two years
in a row. However, military funding obstacles intervened.

If you need more information about CopterBox, or you would like
to place an order for it, please contact DropMaster, Inc. at
910-630-3269, or by email at copterbox@dropmaster.com.

DefenseReview syndicates "Defense Tech" news. "Defense Tech" is
published by Noah Shachtman.

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**DropMaster, Inc.**   
**3600 Abernathy Drive**   
**Fayetteville, NC 28311**   
**copterbox@dropmaster.com**

**Charles V. Warren, President**   
**(910) 630-2997**

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**US Patent # 5,947,419**

**September 7, 1999**

**Aerial Cargo Container**

**Abstract**

An aerial cargo container system for transporting cargo from an
aircraft to the ground having a cargo box with a continuous side
wall with six rectangular side panels, and rotor blades having
stowed positions against alternating box side panels and
deployed positions extending outwardly from the box in a
generally horizontal plane. Each blade may include a lower panel
and an upper panel that has two triangular sections behind the
leading edge that forms an aerodynamic camber. The blades are
hinged to a rotor hub secured across the top of the box. The
upward deployment of the blades is limited by tethers extending
from the blades down to a tether attach frame secured across the
bottom of the box. The box and blades are preferably formed of
corrugated paper or plastic material. The entire unit rotates
with the load to create aerodynamic braking and lower cargo to
the ground with a minimum of energy being translated to the
cargo on impact.

**Inventors:  Warren; Charles M. (Perry, GA), Warren;
Charles V. (Fayetteville, NC)**

Current U.S. Class:  244/138A ; 102/384; 102/388; 244/1TD;
244/137.4   
Current International Class:  B64D 19/02 (20060101); B64D
19/00 (20060101); B64D 1/00 (20060101); B64D 1/02 (20060101);
B69D 001/08 (); F42B 010/60 ()

**References Cited --- U.S. Patent Documents:**   
 2324146  July 1943  Frazer   
 2450992  October 1948  Sanderson   
 2495486  January 1950  Stevenson   
 2776017  January 1957  Alexander   
 2917255  December 1959  Boyd   
 2969211  January 1961  Saurma   
 3115831  December 1963  Suter   
 3168267  February 1965  Ferris   
 3194519  July 1965  Rhodes   
 3265136  August 1966  Wojciechowski et al.   
 3273834  September 1966  Bower   
 3342439  September 1967  Behrendt   
 3401906  September 1968  Girard   
 4890554  January 1990  Schleimann-Jensen

**Description**

**BACKGROUND OF THE INVENTION**

**(1) Field of the Invention**

The present invention relates generally to an apparatus for
transporting cargo from an aircraft to the ground, and in
particular to an improved, disposable cargo container comprised
of a box with extendible rotor blades that can be dropped from
an aircraft to the ground under adverse conditions without
damage to the cargo.

**(2) Description of the Prior Art**

Numerous circumstances require the transport of various kinds
of cargo to inaccessible or remote areas where ground
transportation is not possible or timely. These circumstances
include both military and peacetime conditions, such as
providing emergency food, fuel and medical supplies to victims
of natural disasters, fighting of forest fires, etc.

In many instances, the cargo can be transported to the area by
helicopter, or dropped from an airplane with a parachute.
However, helicopters are not always readily available, and are
expensive to operate. Parachutes are also expensive,
particularly when used to drop relatively small quantities of
cargo, and are usually not recoverable due to the terrain and
the conditions under which the cargo is dropped.

Various prior art patents, since at least as early as the
1940s, have proposed an alternative means involving the dropping
of containers of small cargo loads from an aircraft without a
parachute. Instead, the container is constructed of a disposable
box with attached wings or rotor blades that extend outwardly
when the box is dropped from an aircraft. The force of the air
against the lower surface of these blades causes the blades to
turn in the direction of their leading edges, rotating the
attached box and creating lift to slow the container's descent.

The following patents are representative of these prior art
devices:

Patent Number Inventor   
2,450,992 Sanderson   
3,168,267 Ferris   
2,324,146 Frazer   
2,495,486 Stevenson   
3,115,831 Suter

This alternative transport means, while conceptually addressing
the need for inexpensive cargo delivery, has apparently found no
significant application. This lack of use is believed to be
attributable to two somewhat related reasons; cost effectiveness
and durability. In order for this type of devise to find a niche
in cargo transport, the cost must be low since the container is
not recovered. However, prior art designs that could be produced
at an acceptable cost do not have the durability to withstand
the destructive forces to which they are subjected, resulting in
failure of the systems to get their load to the intended
destination undamaged. However, the need remains and the basic
concept is appealing. Therefore, a disposable aerial cargo
container that could be manufactured at an acceptable cost while
still having the required strength and durability should be of
considerable utility.

**SUMMARY OF THE INVENTION**

The following summary describes an improved aerial cargo
container useful in transporting cargo from an aircraft to the
ground. This cargo container incorporates features not suggested
by the prior art that enable production of the container at an
acceptable cost, while still providing the strength and
durability necessary for transportation of cargo loads of sixty
(60) pounds or more under adverse conditions without significant
damage to the cargo upon impact with the ground.

Essentially, the performance of the cargo container of the
present invention is attributable to various modifications and
refinements of cargo containers of the type described in the
above prior art. That is, the present container, like prior art
containers, is comprised of a box for holding the cargo to be
transported, and a plurality of wings or rotor blades having
hinged roots, with the blades being deployable to a
substantially horizontal attitude when the container is dropped
from the aircraft. As with prior art containers, air pressure
against the rotor blades causes the box to rotate and create
aerodynamic lift to slow the descent of the container.

The cargo container of the present invention, however,
incorporates various features not suggested by the prior art.
These improvements reside in the following three areas: 1) the
box or cargo holder construction and blade positioning, 2)
attachment of the rotor blades, and 3) the rotor blade
construction. Each improvement contributes to the economical
construction of the container and to its superior performance.
Depending upon the particular container and its uses, these
features may be used alone or in combination.

The configuration of the cargo box and the placement of the
rotor blades thereon can dramatically affect various aspects of
the container including its carrying capacity, its durability,
and its cost of manufacture. It has been determined that the
preferred cargo box addressing these concerns is a box with a
hexagonal cross-section comprised of a continuous side wall
formed of six rectangular attached facets that are positioned in
a hexagonal configuration, and a hexagonal end wall closing one
end of the box formed by the side wall material. The open end of
the container is closed with a hexagonal shaped plug type lid to
enclose the cavity.

The box walls, for purposes of disposability and economy, are
preferably formed of corrugated paper or hardboard. The
continuous sidewall may be formed of a single sheet with spaced
creases to form the individual panels. The abutting ends of the
sheet are joined, e.g., by taping, staples or glue.
Alternatively, the sidewalls can be formed of six rectangular
panels that are joined to each other at their abutting side
edges. The size of the box will depend upon the type of cargo to
be transported and the cargo size and weight. Generally, however
a box with a length from about 32 to about 36 inches and a
diameter from about 15 to about 18 inches will be suitable for
most cargo up to a weight of about 60 pounds. Thus, each side
panel will have a length of from about 32 to about 36 inches and
a width of from about 15 to about 18 inches.

The container includes three rotor blades, with each blade
being positioned adjacent to alternating side panels. Thus, a
container formed of six side panels will have three rotor
blades, with one blade adjacent to every other panel. When the
container is stowed, the rotor blades are folded against the
side panels and, when deployed, extend outward from the box in a
substantially horizontal plane substantially perpendicular to
the side panels. In order to achieve maximum lift, while still
being easy to store, the blades preferably have length and width
dimensions approximating the corresponding dimensions of the
side panels.

In prior art disposable cargo containers, rotor blades have
been hinged at their root to one panel or side of the container
box. Since disposable boxes, of economic necessity, are usually
made of corrugated paper, or another disposable material with
low tear strength, forces against the rotor blade caused by air
pressure and the centrifugal force tends to rip the hinge, and
often part of the box. Separation of one or more rotors during
flight can be disastrous to the load since the container will
probably plummet to the ground, damaging the cargo.

In the present invention, this deficiency has been addressed by
the use of a separate rotor blade hub positioned at the closed
(upper) end of the box, with the rotor blades being hinged at
their roots to the hub, instead of directly to the box.
Preferably, the hub is in the shape of a metal wire frame that
extends over the top and upper edges of the box. The rotor hinge
points on the hub are located on the support adjacent
alternating box panels, with hinge pins being used to attach the
rotor blades to the hinge points of the hub. Thus, the
centrifugal force exerted by the blades act upon each other
through the hub and not the box. Preferably, the hub includes a
common central point with connections from the central point to
each of the hinge points. With this arrangement, the rotor
blade's centrifugal forces tend to act against each other to
negate the stresses and loads on the box.

Upward movement of the blades during deployment and flight is
limited by tethers and shock cords having their upper ends
attached to the blades and their lower ends attached at the lid
(lower) end of the box. The tethers may be resilient, such as a
bungee cord, or a non-resilient cord of a material such as
nylon.

The lower ends of the tethers can be attached directly to the
box. However, since the tethers are also subjected to high
forces, particularly during deployment, the box preferably
includes a tether attachment frame that extends across the
bottom wall (lid). This tether attachment frame includes
attachment points to secure the lower end of each tether
approximately beneath the rotor blade to which the upper end of
the tether is attached. For example, the attachment frame can be
in the shape of an equilateral triangle having apexes that
extend beyond the periphery of the box under the alternating
panel over which the panels are positioned, with one tether
being attached at each apex of the triangle.

Prior art rotor blades for expensive devices have been made of
metal or wood. However, rotor blades for containers designed for
the purpose of the present invention, have been made from a
planar piece of corrugated paper or polymer to reduce cost.
These latter blades are not of sufficient strength to withstand
the forces to which the container is subjected or to create
significant aerodynamic braking due to lift. The present
invention solves this problem with a rotor blade that is made
from a single corrugated material sheet or a plurality of
segments joined in a particular manner to provide the needed
structural integrity under incurred aerodynamic and centrifugal
loading, while maintaining the required economy.

Basically, the improved rotor blade is comprised of a lower
facet, and a multi-facet upper panel secured to the lower panel
to form an integral blade. The lower panel is essentially planar
and of a single facet, with leading and trailing edges, which
may have constant or varying chord distance between them along
the span of the blade. Together, the panels form a blade having
a planar bottom surface, and a top surface that includes an
upwardly extending forward triangle adjacent to the leading edge
of the blade and a planar surface extending downwardly and
rearwardly from the forward triangular section aft to a point
forward of the trailing edge, forming and aft triangular
section. A pocket for a structural spar exists between these two
triangular sections.

To form the forward triangular section, the front segment is
inclined upward and back from the leading edge of the blade. A
generally vertical forward spar pocket segment has an upper edge
common to the rear edge of the upper forward segment of the
forward triangular section, and a lower edge abutting the lower
panel.

The center segment spar pocket common to the upper panel has a
front edge adjacent and parallel to, but not necessarily
abutting, the rear edge of the front segment, and is inclined to
the rear and down to a rear edge that also abuts the lower
panel. A generally vertical spar has an upper edge integral with
the front edge of the center segment, and a lower edge abutting
the lower panel.

The rear segment of the upper panel is generally planar and
abuts the upper surface of the lower panel, and has a front edge
integral with the rear edge of the spar pocket and a rear edge
integral with the rear edge of the lower panel.

The lower and upper facets of the rotor blade can be made from
a single corrugated material that is folded along the
longitudinal axis of the blade to form the panel segments. That
is, the blade can be formed by longitudinally folding the outer
sides of a paper sheet over a planar central section that forms
the lower panel. One side of the sheet is creased to form the
front segment and forward spar pocket segment, while the other
side of the sheet is folded to form the rear and central
segments of the upper panels, and the aft spar pocket segment.

A folded piece of corrugated material is inserted in the spar
pocket and forms the spar. The top of the spar is even with the
top of both the forward and aft triangular segments. The spar
translates the aerodynamic forces to the tether and the box. The
front and central segments of the upper panel, supported by the
spar and the spar pocket, form a raised triangular section along
the top of the blade parallel to the blade's longitudinal axis
and adjacent the blade's leading edge. This triangular section
forms the structural rigidity of the rotor, as well as providing
the aerodynamic camber required to generate lift.

The tether is attached to the spar in such a way to translate
all of the aerodynamic lift and planar drag to the box from the
rotor blade. The upper end of the tether can extend through the
blade's lower facet and around the spar and spar pocket, and
then back through the lower facet to form a loop.

The box is designed to be loaded upside down. That is, the lid
end of the box that will be in a down position when the box is
in flight will be oriented upward during loading. For this
discussion, box orientation convention will be rotor hub end
down and lid end up. Thus, when assembled and oriented for
loading, the box has a continuous sidewall formed of six
adjacent, rectangular side panels, and a lower hexagonal end
wall secured across the rotor hub end of the box. The box is
inserted into the rotor hub, which forms a base or skid upon
which the container rests. The rotor blades are attached at
their root hinge points, to the support, and are folded up
against the sidewalls of the box. A breakaway strap or other
means of sacrament is used to hold the blades in their folded
position during loading and transport to the drop zone.

When loading, a spacer may first be inserted into the
container. This spacer serves two purposes. First, the spacer
prevents cargo from being loaded into what will become the upper
end of the container after deployment, thereby ensuring that the
center of gravity of the box will be near the centroid of the
cavity to ensure positive blade deployment. Also, the spacer,
which can be of an expanded material, such as honeycomb paper,
can absorb some of the shock of loading and carriage in the
aircraft.

After the payload is centered and chocked with disposable
packing along the vertical axis of the box, the hexagonal plug
lid is secured in the open end. This lid is constructed of
honeycomb or expanded material which will tend to crush upon
landing, absorbing shock and dissipating the deceleration
forces. The tether attach frame is placed over the lid and
strapped into place with a packing strap that runs around the
rotor hub and the entire box. The strap will hold the lid, the
tether attach frame, and the rotor hub in place on the box until
the aerodynamic and deceleration loads can hold the assembly
together in flight. Once the box has landed, the strap is
removed to unpack the payload.

The loaded container is then placed in the same orientation in
which it was loaded in an aircraft and flown to the drop area.
The box is pushed from the aircraft over the drop zone with a
static line or other mean removing the blade-restraining strap
that allows the blades to deploy. The relative wind around the
box causes a lifting force to deploy the rotor blades which
rotate about their hinge attach points and are snubbed by the
tethers and the shock cords. The blades will be limited to a
substantially horizontal orientation, i.e. plus or minus ten
(10) degrees of horizontal by the tethers. In turn, the tether
attach frame absorbs the tension in the tethers instead of the
box.

The force of the air against the lower facet of the blades,
with the leading edges of the blades being lower than their
trailing edges, causes the container to rotate in the direction
of the leading edges, and accelerate rotationally until it
achieves rotational terminal velocity, generating maximum
aerodynamic lift, thereby slowing the box to its terminal
vertical velocity. Centrifugal forces acting on the blades that
heretofore could cause the blades to rip from the box during
deployment and rotation are absorbed by the rotor hub.

The triangular facets of the rotor blades creates an
aerodynamic camber and form structural box beams to insure rotor
blades stiffness until centrifugal force stiffening can assist
the structure during maximum deceleration. This slower rate of
descent minimizes damage to cargo upon impact of the container
with the ground. The crushable shock-absorbing lid further
lessens the risk of damage to the payload.

Accordingly, one aspect of the present invention is to provide
an aerial cargo container comprising a box having a continuous
side wall formed of six rectangular side panels, an upper end
wall at one end of the side wall and a lower end wall at the
opposite end of the side wall, the walls forming a cargo cavity;
and three rotor blades having hinged roots, the blades having a
stowed position against alternating side panels and a deployed
position extended outwardly in a generally horizontal plane.

Another aspect of the present invention is to provide an aerial
cargo container comprising a cargo box having a continuous side
wall, a first end cap and a second end cap; a rotor hub across
the first end cap; and a plurality of rotor blades having
leading and trailing edges, and root hinged to the rotor hub,
the blades having a stowed position against the box and a
deployed position extending outwardly from the box in a
generally horizontal plane.

Still another aspect of the present invention is to provide an
aerial cargo container comprised of a cargo box with a plurality
of rotor blades with leading and trailing edges, each of the
blades having a stowed position against the box and a deployed
position extending outwardly from the box in a generally
horizontal plane, the blades being formed of corrugated material
and having a planar lower surface and an upper surface that
includes triangular raised sections adjacent the leading and
trailing edges.

Another aspect of the invention is to provide an aerial cargo
container comprising of a box having a continuous side wall
formed of six rectangular side panels, an upper end wall at one
end of the side wall and a lower end wall at the opposite end of
the side wall, the walls being constructed of corrugated
material and forming a cargo cavity; three rotor blades having
leading and trailing edges, and inner root ends, the blades
having a stowed position against alternating side panels of the
side wall and a deployed position extending outwardly from the
box in a generally horizontal plane, each of the blades consists
of a lower panel and an upper panel, made up of two triangular
boxes, a spar pocket and a spar. The front triangular box is
adjacent to the leading edge of the blade, the rear triangular
box is adjacent to the trailing edge, abutting the lower panel,
and the central section between the two triangular boxes
consisting of the spar pocket and the spar contained therein; a
rotor hub across the first end wall, the root ends of the blades
being hinged to the hub; a tether attach frame across the second
end wall; and blade tethers attached to the blade spars to the
tether attach frame.

These and other aspects of the present invention will become
apparent to those skilled in the art after a reading of the
following description of the preferred embodiment.

**BRIEF DESCRIPTION OF THE DRAWINGS**

**FIG. 1** is a perspective view of the upright and deployed
cargo container as if it were in flight.   
    
 

![](5947-1.jpg)

**FIG. 2** is sectional side view of one of the rotor blades
showing the tether attachment.

![](5947-2.jpg)

**FIG. 3** is a top view of the container showing the rotor
blade root hinges.

![](5947-3.jpg)

**FIG. 4** is a bottom view of the container showing the
tether attach frame and plug lid.

![](5947-4.jpg)

**FIG. 5** is a sectional side view of the container in the
loaded and stowed position.

![](5947-5.jpg)

**DETAILED DESCRIPTION OF THE INVENTION**

In the following description, terms such as horizontal,
upright, vertical, above, below, beneath, and the like, are used
solely for the purpose of clarity in illustrating the invention,
and should not be taken as words of limitation. The drawings are
for the purpose of illustrating the invention and are not
intended to be to scale.

As best shown in the drawings, a preferred embodiment of the
container includes a box, generally 10, a rotor hub 12, three
rotor blades 14, a tether frame 16, and strut tethers 18.

Box 10 is formed of six rectangular side panels joined at their
abutting edges to from a continuous sidewall 20. An upper
hexagonal end wall 22 closes the upper end of wall 20 and a
lower hexagonal honeycomb plug lid 24 closes the opposite end of
wall 20. A load spacer 28 is inserted into the interior of box
10 adjacent wall 22 during loading of box 10 to position the
payload closer to the centroid of the box

Rotor hub 12 is formed of a lightweight welded wire or extruded
plastic cage extending across end cap 22 and around the upper
ends of wall 20. Hub 12 is strengthened by the use of a central
plate 30 and three triangular sections 32 with their apexes
welded or formed to plate 30 and their bases adjacent the upper
ends of alternating side panels of wall 20.

Blades 14 are hinged at their roots to hub 12 with hinge pins
34, which extend through hinge points 36 extending from hub 12
on alternating sides. In order for the box to rotate and create
aerodynamic lift, the chord line of each rotor blade is set at a
negative angle of incidence from a horizontal line that is
parallel to the end cap 22. This angle creates rotative forces
that spin the entire assembly. The angle of incidence is between
minus four (-4) and minus six (-6) degrees. At the lower end of
the container, a tether frame 16 extends across plug lid 24.
Tethers 18 extend from the tether frame 16 to approximately the
mid-span of each rotor blade 14.

As shown in FIG. 2, each rotor blade 14 consists of a folded
corrugated material that forms a lower panel 38, an upper panel
comprised of a front segment 40, a spar pocket 46, a trailing
segment 42, a rear segment 44, and a spar 48 inserted and bonded
into the spar pocket formed by 46. Each blade of the preferred
embodiment is formed of a single corrugated piece, with the
corrugations being parallel to the span of the blade. A hinge
tube 50 is attached to the root of each blade by a root
re-enforcement plate or strap 52. Plate 52 stiffens the blade
root and helps to translate the centrifugal and twisting forces
to hub 12.

The container is positioned as shown in FIG. 5 when being
loaded and transported. Spacer 28 is inserted into the container
cavity, followed by the cargo (C). After loading, the plug lid
24 and tether attachment plate 16 are secured in place with a
strap assembly 54 by securing the hub 12 and frame 16 to the box
10. Tethers 18 from each rotor 14 are attached to attach frame
16. The rotors 14 are secured with rotor containment strap 54.
The box is loaded in the aircraft and the blade containment
system is attached to the blade deployment static line in the
aircraft. The box is pushed out of the aircraft and blade
containment strap 54 is released, causing all three blades 14 to
be deployed into the relative wind. The box starts to rotate,
generating aerodynamic braking forces by generating lift. This
aerodynamic lift is translated through the struts to the tether
attach frame 16 which then directs the force through the plug
lid 24 to the cargo (C). This force will stabilize when the box
and load decelerate to the terminal velocity. This is the
minimum velocity the box achieves before landing.

Certain modifications and improvements will occur to those
skilled in the art upon a reading of the foregoing description.
It should be understood that all such modifications and
improvements have been deleted herein for the sake of
conciseness and readability but are properly within the scope of
the follow claims.

---



**US Patent #  6,712,317**

**March 30, 2004**

**Aerial Cargo Container with Deceleration
and Orientation Assembly**

**Abstract**

An aerial cargo container is described that includes a cargo
box with a plurality of hinged rotor blades having a stowed
position against the sides of the box and a deployed position
extending outwardly from the box, and a deceleration and
orientation assembly to slow the descent of the container and
align the longitudinal axis of the container with the relative
wind direction, thereby minimizing damage to the blades upon
opening. The assembly includes a drogue chute, a blade retainer
to secure the blades in the stowed position, and a folded
metering cord attached between the drogue chute and the box, and
a segment securing the blade retainer, whereby the cord segments
unfold sequentially upon exertion of a force to slow and orient
the container, prior to release of the blade retainer to permit
movement of the blades to their deployed positions.

Inventors:  Warren; Charles V. (Fayetteville, NC),
Fitzgerald; Charles G. (Cameron, NC)   
Current U.S. Class:  244/138R ; 244/142; 244/147   
Current International Class:  B64D 1/00 (20060101); B64D
1/08 (20060101); B64D 19/00 (20060101); B64D 001/08 ()   
Field of Search:  244/138R,142,147,148,149,150 102/386   
References Cited --- US. Patent Documents:   
 2440293  April 1948  Stanley   
 3333643  August 1967  Girard   
 3362665  January 1968  Larsen et al.   
 3497168  February 1970  Finney et al.   
 3540684  November 1970  Snyder   
 3586257  June 1971  Zelinskas   
 3662978  May 1972  Hollrock   
 3838940  October 1974  Hollrock   
 4017043  April 1977  Barzda   
 4131392  December 1978  Barzda   
 4379534  April 1983  Miller et al.   
 4765570  August 1988  Herndon   
 5232184  August 1993  Reuter   
 5263663  November 1993  Widgery   
 5309412  May 1994  Bourgeois   
 5947419  September 1999  Warren et al.   
 6164594  December 2000  Pignol et al.

**BACKGROUND OF THE INVENTION**

**(1) Field of the Invention**

The present invention relates generally to an improved,
disposable cargo container comprised of a box with extendible
rotor blades that can be dropped from an aircraft to the ground,
and in particular to a disposable cargo container that includes
a mechanism for decelerating and orienting the container before
extension of the rotor blades, thereby reducing the possibility
of damage to the container.

**(2) Description of the Prior Art**

Numerous circumstances require the transport of various kinds
of cargo to inaccessible or remote areas where ground
transportation is not possible or timely. These circumstances
include both military and peacetime conditions, such as
providing emergency food, fuel and medical supplies to victims
of natural disasters, fighting of forest fires, etc.

In many instances, the cargo can be transported to the area by
helicopter, or dropped from an airplane with a parachute.
However, helicopters are not always readily available, and are
expensive to operate. Parachutes are also expensive,
particularly when used to drop relatively small quantities of
cargo, and are usually not recoverable due to the terrain and
the conditions under which the cargo is dropped.

Various prior art patents since at least as early as the 1940s
have proposed an alternative means involving the dropping of
containers of small cargo loads from an aircraft without a
parachute. Instead, the container is constructed of a disposable
box with attached wings or rotor blades that extend outwardly
when the box is dropped from an aircraft. The force of the air
against the lower surface of these blades causes the blades to
turn in the direction of their leading edges, rotating the
attached box and creating lift to slow the container's descent.

This alternative transport means, while conceptually addressing
the need for inexpensive cargo delivery, has apparently found no
significant application. This lack of use is believed to be
attributable to two somewhat related reasons; cost effectiveness
and durability.

A disposable aerial cargo container that addresses these prior
art deficiencies, i.e., a container that can be manufactured at
an acceptable cost while still having the required strength and
durability necessary for transportation of cargo loads of up to
about sixty (60) pounds or more under adverse conditions without
significant damage to the cargo upon impact with the ground is
described in U.S. Pat. No. 5,947,419, issued Sep. 7, 1999 to
Warren et al., and incorporated herein by reference.

The Warren et al. container, like prior art containers, is
comprised of a box for holding the cargo to be transported, and
a plurality of wings or rotor blades having hinged roots, with
the blades being deployable to a substantially horizontal
attitude when the container is dropped from the aircraft. As
with prior art containers, air pressure against the rotor blades
causes the box to rotate and creates aerodynamic lift to slow
the descent of the container. The preferred Warren et al.
container includes a cargo box with a hexagonal cross-section
comprised of a continuous side wall formed of six rectangular
attached facets that are positioned in a hexagonal
configuration, and a hexagonal end wall closing one end of the
box formed by the side wall material. The open end of the
container is closed with a hexagonal shaped plug type lid to
enclose the cavity. Alternatively, both ends of the box can be
closed and the plug placed inside the box to act as a crushable
or frangible cushion of landing. The box walls, for purposes of
disposability and economy, are preferably formed of corrugated
paper or hardboard.

The preferred Warren et al. container includes six side panels
with three or more rotor blades, one blade adjacent to every
other panel depending on the number of blades used. When the
container is stowed, the rotor blades are folded against the
side panels and, when deployed, extend outward from the box in a
substantially horizontal plane substantially perpendicular to
the side panels. In order to achieve maximum lift, while still
being easy to store, the blades preferably have length and width
dimensions approximating the corresponding dimensions of the
side panels.

While the rotor blades may be hinged at their root to one panel
or side of the container box, there is a risk of separation of
one or more rotors during flight, causing the container to
plummet to the ground, damaging the cargo. In the Warren et al.
invention, this deficiency is addressed by the use of a separate
rotor blade hub positioned at the closed (upper) end of the box,
with the rotor blades being hinged at their roots to the hub,
instead of directly to the box. Preferably, the hub is in the
shape of a metal wire or composite material frame that extends
over the top and upper edges of the box. The rotor hinge points
on the hub are located on the support adjacent alternating or
sequential box panels, with hinge pins being used to attach the
rotor blades to the hinge points of the hub. Thus, the
centrifugal force exerted by the blades act upon each other
through the hub and not the box. Preferably, the hub includes a
common central point with connections from the central point to
each of the hinge points. With this arrangement, the rotor
blade's centrifugal forces tend to act against each other to
negate the stresses and loads on the box.

Upward movement of the blades during deployment and flight is
limited by tethers and shock cords having their upper ends
attached to the blades and their lower ends attached at the lid
(lower) end of the box. The tethers may be resilient, such as a
bungee cord, or a non-resilient cord of a material such as
nylon. Since the tethers are also subjected to high forces,
particularly during deployment, the box preferably includes a
tether attachment frame that extends across the bottom wall
(lid). This tether attachment frame includes attachment points
to secure the lower end of each tether approximately beneath the
rotor blade to which the upper end of the tether is attached.
For example, the attachment frame can be in the shape of an
equilateral triangle having apexes that extend beyond the
periphery of the box under the alternating panel over which the
panels are positioned, with one tether being attached at each
apex of the triangle. Alternatively, a hub similar to the rotor
hub can be placed on the bottom of the container to protect the
box during handling and serve as a multiple (up to six) attach
points for the tethers for all the blades.

Unlike earlier prior art rotor blades of metal or wood, the
Warren et al. rotor blades are made from a planar piece of
corrugated paper or polymer, either in the form of a single
corrugated material sheet or a plurality of segments joined in a
particular manner to provide the needed structural integrity
under incurred aerodynamic and centrifugal loading, while
maintaining the required economy. Each rotor blade is comprised
of a lower facet, and a multi-facet upper panel with a
multi-faceted forward section, a rotor spar of wood or other
material, and a generally planar rear section secured to the
lower panel to form an integral aerodynamically-shaped blade.

When loaded, the rotor blades are held against their respective
box facets by a blade restraining strap. At the drop zone, the
box is pushed from the aircraft with a static line or other
means removing the blade-restraining strap. The relative wind
around the box causes a lifting force to deploy the rotor blades
which rotate about their hinge attach points and are snubbed by
the tethers and the shock cords. The blades will be limited to a
substantially horizontal orientation, i.e. plus or minus ten
(10) degrees of horizontal by the tethers. In turn, the tether
attach frame absorbs the tension in the tethers instead of the
box. The force of the air against the lower facet of the blades,
with the leading edges of the blades being lower than their
trailing edges, causes the container to rotate in the direction
of the leading edges, and accelerate rotationally until it
achieves rotational terminal velocity, generating maximum
aerodynamic lift, thereby slowing the box to its terminal
vertical velocity.

While the Warren et al. cargo container is a significant
improvement over prior art containers, there is still a risk of
damage to the container and its contents when the container is
released from the aircraft, particularly with heavy and
asymmetrical loads or when the container is being deployed in
high relative winds (airspeeds). As noted above, the rotor
blades in the Warren et al. container are released for movement
to their deployed or extended position from their stowed
position as the container is released from the aircraft. As a
result, the blades extend while the container is dropping
rapidly, exerting considerable force on the blades and the
hinged attach points. After the blades are fully extended and
the container is rotating, the container will orient so that an
equal force is exerted on all blades. However, when the
container is dropped from a moving aircraft, the orientation of
the container may be such that unequal blade forces are exerted.
These unequal forces, particularly if the container is moving at
a high rate of speed, may cause damage to one or more rotor
blades, or prohibit their deployment.

Thus, the utility of containers constructed similar to the
Warren et al. container, would be considerably enhanced, and the
risk of damage decreased, if the container could be oriented and
its descent slowed prior to deployment of the rotor blades. By
slowing the container prior to blade deployment, the container
will be farther away from the drop aircraft, insuring that the
container is not struck by the aircraft.

**SUMMARY OF THE INVENTION**

In general, the desired results of the present invention are
achieved by adding a deceleration and orientation assembly, also
referred to herein as a delay assembly for brevity, as described
herein in detail, to cargo containers of the type that include a
cargo box with hinged blades having a stowed position against
the box and a deployed position extending outwardly from the
box.

The delay assembly of the present invention is generally
comprised of an air resistance device, such as a drogue chute; a
blade retainer adapted to secure the rotor blades in their
stowed position; and a folded metering cord that has one end
attached to the resistance device, an opposed end attached to
the top of the container, and a segment attached to the blade
retainer. Preferably, the metering cord includes a plurality of
folds that are adapted to unfold in sequence.

When loading the container, the bottom cage or hub with the
respective blade tethers and rotor blades attached is placed on
the floor. The box is inserted into the bottom cage in its
hexagonal shape and the frangible plug is inserted into the box.
The payload is placed in the box on top of the plug and secured
in the center of the box with packing and dunnage. The top wall
of the box is closed and the rotor hub cage is placed over the
top of the box. The top and bottom hubs are strapped together to
maintain their relative position with each other with the box in
between them. The rotor blades are then pinned in place to the
rotor hinge clips on the upper hub and secured. The delay
assembly and blade retaining strap is then attached and secured
for transport to the aircraft for launch.

When the cargo container is discharged from the aircraft, the
drogue chute or other drag device, e.g., a streamer, exerts a
drag due to wind resistance, creating tension on the metering
cord, sequentially opening folds of the cord, thereby slowing
the descent of the container. At the same time the cord tension
orients the container so that its axis is aligned with the wind
direction. Following deceleration and orientation, the blade
retainer is released permitting the rotor blades to open to
their extended position. Since the container is moving at a
slower speed, and since the force of the air is approximately
equal against all of the blades, all rotor blades will deploy.
Thus, the risk of damage is substantially reduced.

In a preferred embodiment, the metering cord is folded into an
a plurality if S-type folds, with the folds being secured by
thread that has a breaking strength below the force exerted on
the metering cord during deceleration, e.g., about 15 pounds
force to about 30 pounds force. The number of thread loops
securing the folds is equal to twice the number of folds, with
the upper or outer fold being engaged by one thread loop and
each half sequential fold being engaged by a one additional
thread loop. The lower fold, used to secure the blade retainer
is sewn with all thread loops and therefore the last to break.

When a force exceeding the breaking strength of the thread is
exerted on the cord, the single loop holding the outer fold is
broken, allowing the outer fold to open. As a result, a brief
drop in restraining force against the container is followed by
an increased force, or tug, acting to decelerate and orient the
container. The continuing force on the cord then causes the
second loop to break, allowing the next fold to open with a
similar effect. This sequence continues until the final thread
holding the lower elongated fold is broken, resulting in pulling
of the elongated fold from the blade retainer, and permitting
the blades to open.

**BRIEF DESCRIPTION OF THE DRAWINGS**

**FIG. 1** is a perspective view of a cargo container with
the metering assembly.

![](6-1.jpg)

**FIG. 2** is perspective view of the upper end of a
deployed cargo container illustrating the open housing and
extended cord.

![](6-2.jpg)

**FIG. 3** is a sectional side view of a folded and tied
metering cord.

![](6-3.jpg)

**FIG. 4** is a top view of a cargo container illustrating
attachment of the cord to the hub.

![](6-4.jpg)

**FIG. 5** is a perspective view of the deployed container
during descent with the attached drogue chute.

![](6-5.jpg)

**DETAILED DESCRIPTION OF THE INVENTION**

In the following description, terms such as horizontal,
upright, vertical, above, below, beneath, and the like, are used
solely for the purpose of clarity in illustrating the invention,
and should not be taken as words of limitation. The drawings are
for the purpose of illustrating the invention and are not
intended to be to scale.

The preferred embodiment of the present invention will be
described in the context of the Warren et al. container
discussed above. It will be understood, however, that the delay
assembly can also be used with other cargo containers, as well
as with other items that are deployed aerially without a
parachute in lieu of static line systems now in use.

As best shown in the drawings, a preferred embodiment of the
invention is comprised of a cargo container, generally 10,
having a delay assembly, generally 12, positioned on the top of
container 10. Container 10 is comprised of a box 14 formed of
six rectangular side panels joined at their abutting edges to
from a continuous sidewall, a rotor hub 16 formed of a
lightweight welded wire or extruded plastic cage, three rotor
blades 18, a lower hub 20 similar in construction to hub 16, and
strut tethers 22 joining blades 18 to hub 20. Blades 18 are
hinged at their roots to hub 16 with hinge pins 24. In order for
the box to rotate and create aerodynamic lift, the chord line of
each rotor blade is set at a negative angle of incidence from a
horizontal line that is parallel to the end cap 22. This angle
creates rotative forces that spin the entire assembly. Different
airfoil shapes may need different angles of attack. For example,
the angle of incidence may be between minus four (-4) and minus
six (-6) degrees. Tethers 22 extend from tether frame 20 to
approximately the mid-span of each rotor blade 18.

Delay assembly 12 is comprised of a flexible metering cord 30
that is folded as shown in FIG. 3 prior to deployment and held
in the folded condition by breakable threads 32, a drogue chute
34, and a housing 36, which may be a cardboard box, to enclose
cord 30 and chute 34 prior to deployment. Blade retainer 38 is
stretched around box 14 and blades 18 and secured by a segment
of cord 30. Cord 30 is formed of a flexible material, such as
nylon webbing or a nylon cord that will not break under the
conditions of use. Cord 30 will normally have a length of from
about 15 feet to about 30 feet for use with most containers.

As best illustrated in FIG. 3, cord 30 is initially folded into
a plurality of folds, i.e., an outer fold 40; an elongated inner
fold 42, which serves to secure blade retainer 38; and one or
more intermediate folds 44 between folds 40 and 42. For ease of
packing, and to facilitate a uniform deployment, outer fold 40
and intermediate folds 44 are generally of the same size, while
inner fold 42 will be of a length sufficient to engage blade
retainer 38. For purposes of discussion, it will be understood
that each "fold" is formed of two adjacent, overlapping cord
segments.

As will be discussed in greater detail hereinafter, it is
desirable for the cord folds to open sequentially during
deployment, with outer fold 40 opening first, followed by each
intermediate fold 44 beginning with the intermediate fold
closest to outer fold 40, and finally inner fold 42. To achieve
this sequential opening, the folds are joined by a plurality of
thread loops that will break when subjected to the forces of
deployment. Specifically, an outer thread loop 50 joins all of
the folds together. An inner thread loop 52 joins only the
segments of inner fold 42, and intermediate thread loops 54 join
each intermediate fold 44 to lower fold 42 and all folds between
the particular intermediate fold and the lower fold.
Supplemental breakable threads 56 and 58 may be used to secure
the outer ends of folded cord 30 until deployment. By
duplicating the thread stitch pattern from the inner fold to the
outer fold loop pattern, additional break points can be used to
increase the amount of brake tugs imparted to the container,
thereby slowing down the container prior to lade deployment.

Thus, the folds open sequentially when a pulling force is
exerted between the ends of cord 30, beginning with outer fold
40. That is, outer thread loop 50 initially breaks, since thread
loop 50 is the only thread loop securing outer fold 40. Then,
since fold 44 is secured by only one thread loop, the thread
loop 54 breaks. This sequential breakage and extension of cord
30 continues until inner thread loop 52 is broken, allowing
inner fold 42 to be pulled from blade retainer 38.

Outer end 60 of cord 30 is attached to a drag device, such as
drogue chute 34, with inner end 62 being attached to the top of
cargo container 10, e.g., at the center of rotor hub 16. Folded
cord 30 and drogue chute 34 are packaged within housing 36.
Housing 36 includes an first or upper access opening 66 to
permit removal of drogue chute 34 and cord 30, a second or
bottom access opening 68 that is opened to withdraw inner end 52
of cord 30 for attachment to hub 16, and a third or side access
opening 70 to withdraw inner loop 42 to secure blade retainer
38. Each opening may be covered by a flap or other cover prior
to use.

Blade retainer 38 in the preferred embodiment is comprised of a
stretchable band or strap, e.g., a bungee cord that is stretched
around box 14 and all blades 18 to secure blades 18 in a stowed
position against the sides of box 14. The ends of retainer 38
are held together by inner fold 42. For example, as illustrated
in FIG. 4, the opposed ends of retainer 38 may include closed
loops 74 and 76, with loop 74 being inserted through loop 76 and
the end of inner fold 42 being inserted through loop 74.

When cargo container 10 is to be dropped from an aircraft, the
operator opens the flap or lid covering opening 66 of housing 36
and removes chute 34. Container 10 is then pushed or thrown from
the aircraft. To ensure opening, chute 34 may be briefly held by
the operator or by a breakable static line. As container 10
begins to fall, the force of air resulting from the forward and
downward movement of container 10 opens chute 34, causing a
force to about 30 pounds or more to be exerted on cord 30,
causing folds 40, 44 and 42 of cord 30 to sequentially open.
Each loop break meters the stowed cord and imparts a pull to
decelerate and orient container 10 so that the longitudinal axis
of container 10 aligns with the direction of movement. Finally,
thread loop 52 securing inner fold 42 is broken, resulting in
inner fold 42 being pulled from blade retraining strap 38. As a
result, blades 18 are released to move outwardly to their
extended positions. Thus, when blades 18 extend, the speed of
container 10 has become oriented at the correct attitude and its
descent slowed. Therefore, an equal and reduced force is exerted
on all blades, significantly reducing the possibility of damage
on one or more of the blades.

Certain modifications and improvements will occur to those
skilled in the art upon a reading of the foregoing description.
It should be understood that all such modifications and
improvements have been deleted herein for the sake of
conciseness and readability but are properly within the scope of
the following claims.

---



![](partskiit.jpg)

---