1. Field of the Invention
This invention relates generally to cargo containers capable of withstanding and containing explosions therein. More specifically, the invention is directed at such containers that are also sufficiently lightweight such that it is not cost prohibitive to use them on aircraft.
2. Description of Related Art
In the airline industry, containment devices are commonly referred to as Unit Load Devices (ULDs). Explosion resistant containment devices are known as Hardened Unit Load Devices (HULDs). The specifications (weight, size, shape) for either type of ULD have been partially standardized by regulatory requirements and on account of practical concerns. The odd shape of the containers, with its sloped surfaces is designed so that the ULD fits into the aircraft's fuselage specifically.
Current ULD's are typically constructed of lightweight aluminum or other thin metal or composite materials that provide no protection against an explosive blast and becomes shrapnel during even a small explosion.
A problematic drawback of conventional HULDs or explosion resistant containment devices has been that they are generally heavier than conventional ULDs and cargo containers with thicker walls. While benefits provided by HULDs, including enhanced safety and preventing damage to other cargo, are highly desirable the increase in weight can be cost prohibitive in an already struggling industry.
With airlines already struggling to stay in business and the average traveler for pleasure unwilling to spend more than a certain amount to fly, this increase in weight for safer blast resistant containers can be cost prohibitive. It is unfortunate that the cost of this important safety measure should come at a price so high that it is not implemented. There is a need for a lighter weight, less expensive explosion resistant containment device than those presently available.
When an explosion occurs there is initially a high magnitude shock wave for a short duration followed by lower magnitude, more uniform waves that last much longer. A blast-resistant container must be able to survive both stages and both types of waves. Even the second stage of lower magnitude waves are generally several times atmospheric pressure which is more than the conventional ULD can withstand.
Known techniques for modifying cargo containers to deal with explosions in the fuselage include the venting method, the rigid confining method, and frameless designs. The venting method involves allowing an explosive to penetrate a wall of the fuselage to vent shock waves and high pressures outside the plane. Obviously, controlling the destruction is less ideal than preventing it altogether and is costly due to the damage suffered by the plane. The rigid confining method involves thick, energy-absorbing panels mounted on a rigid frame. The thick panels are focused on absorbing high energy produced during the explosion but the more relevant factor is high stress. Thick panels and a rigid frame can exacerbate concentration of stress at the edges and may be unable to appropriately reduce or redistribute bending stresses. In frameless designs the container is designed to flex, bend, and otherwise deform during a blast. One problem that remains is how to connect the panels to provide structural integrity and how to incorporate a latching mechanism doesn't disproportionately weight down the container.
There is a need for a heat and explosion resistant cargo/baggage container having a panel connection design and latching mechanism that does not undermine the blast resistant nature of the container's panels. The unique door latching/locking mechanism as shown and described herein is easier and faster to operate as compared to the designs incorporated in older Hardened Unit Load Devices (HULDs). One of these older latching/locking mechanism designs consisted of a pair of opposing hook-shape rails and required other tensioning devices (e.g. straps) to make it secure.
Further, there exists a need for a blast resistant cargo/baggage container for aircraft that weighs approximately the same as or less than a conventional, non-hardened, non-blast resistant container. It would be desirable for the walls of the container to be formed of lighter weight materials capable of protecting against an explosive without rupturing and without concentrating too much stress at the edges and near the latch. The present invention meets these needs.
The present invention seeks to provide cost-effective explosion resistant containers so that caution need not be thrown to the wind and aircraft passengers can experience enhanced safety and security of their cargo without any significant increase in fare.
Provided herein is a container having a semi-rigid body structure and explosion resistant enclosure including blast resistant side, floor, roof and door panels. The unit is capable of expanding in a controlled fashion and containing the shock, gas pressure, fragment and post-event combustion resulting from the detonation of an explosive (or improvised explosive device) placed within it.
Briefly and in general terms, the present invention provides an explosion resistant cargo container suitable for aircraft or seagoing vessels for containing the effects of a bomb explosion within the cargo container. The container includes a frame assembly and a plurality of panels mounted to the frame assembly. The plurality of panels include a top explosion resistant panel, a bottom explosion resistant panel, a plurality of explosion resistant side panels, and an explosion resistant flexible door having two side edges and a bottom edge. The side panels and flexible door are both formed of a plurality of explosion resistant sheets, each sheet of said plurality being formed of an explosion resistant, flexible, high tensile strength material. The plurality of explosion resistant sheets are wrapped around and secured to a rod at their edges.
Additionally, there are a plurality of edge capturing rails, each edge capturing rail wrapped around each plurality of explosion resistant sheets over each edge rod, securing adjacent edges of the panels together along with a plurality of fasteners, each fastener extending through two or more panels and an edge capturing rail.
The bottom explosion resistant panel serving as the floor or base of the container may be made of a combination of explosion resistant sheets and metal sheet, metal preferably being on the exterior side to withstand routine handling and flight missions. The frame structure of the blast resistant container may be similar to that of a conventional, non-hardened cargo container. For example, frame members are joined together by gussets or brackets. The rigid frame structure is designed to carry the intended cargo load in flight and to maintain stability of the container during ground handling.
The blast resistant side, roof and floor panels are joined together via innovative edge connections, which match the maximum strength of the panel material. Accordingly, the edge connections do not stand out as the weakest link vulnerable to giving out in the event of an explosion. Rather the strength of the container is consistent throughout which enhances its durability.
The container described herein, constructed in accordance with the principles of the invention, improves upon currently available explosion resistant containers to provide superior performance through a reaction mechanism that includes stretching, flexing, and slight movement of the door along the doorposts and door sill. For example, the design for the latching mechanism includes a detent bar mounted to the frame assembly with guide pins through oversized holes such that the detent bar can extend and retract via movement of the guide pin within the hole. These features assist to dissipate explosive forces in a manner that does not substantially weaken panel materials over time or permit a pressure buildup. In any event, if a panel were to be damaged the container is designed with the desirable feature of permitting replacement of individual panels to provide greater product life and cost savings.
The door opening is framed by two rigid doorposts, a sill, and a rigid header. The flexible door is semi-permanently attached to the roof with the same type of edge connection as those that attach the side panels to the roof. The attachment is semi-permanent in that while the panels are not releasable while the container is in service, they can be disengaged when necessary to replace a single panel. The door panel is latched to the two vertical doorposts and the door sill through a unique locking mechanism when the door is closed.
During an explosion, the interconnected blast resistant panels will expand together much like an air bag in a controlled fashion, largely independent of the rigid frame structure. The blast energy is dissipated largely through interlayer de-lamination and tensile straining of the blast resistant panels. Since the container fully envelops and internalizes the blast effects, e.g. shock, fragment and gas pressure, the momentum of the container towards any random direction is relatively small. In other words, the tendency of the container to launch itself towards a certain favored direction during the explosion is minimal. Therefore, the impact on the surrounding aircraft structure by the container is minimized.
According to a presently preferred aspect, at each corner of the explosion resistant cargo container there is a second edge capturing rail segment on a second side of the container oriented in an approximate position of a first edge capturing rail segment on a first side of the container rotated by 180 degrees.
According to another presently preferred aspect, the explosion resistant cargo container includes a spacer member between adjacent panels configured such that the fastener extends through two of the panels, the edge capturing rail segment, and the spacer member. The spacer member may be an extension of a base rail of the frame assembly. Or, the spacer member may be an extension of a roof beam of the frame assembly.
According to another presently preferred aspect, the edges of the panels of the container with which the flexible door panel mates include an outboard doorpost, an inboard doorpost, and a bottom door sill. The explosion resistant cargo container may also include a latch configured to secure and release the flexible door panel, the latch disposed along an edge of each of the outboard doorpost, the inboard doorpost, and the bottom door sill. Each of the two side edges and the bottom edge of the flexible door panel may have a locking rail segment extending along a length thereof beyond the edge capturing rail segment and receivable by a corresponding hook within the latch of the outboard doorpost, the inboard doorpost, or the bottom door sill, respectively. The explosion resistant cargo container may also include a detent bar on the latch, the detent bar configured to lock the locking rail segment of the two side edges and the bottom edge of the flexible door panel within the corresponding hook of the latch on the outboard doorpost, the inboard doorpost, and the bottom door sill, respectively. The explosion resistant cargo container according to any of the aspects outlined above may include a handle on the latch on an outside of the container.
According to some aspects, the detent bar may have a plurality of protruding teeth configured to be received in corresponding slots of the outboard doorpost, the inboard doorpost, or the bottom door sill of the frame assembly. Each detent bar may have a plurality of holes, including a first hole configured for mounting a handle lever and a second hole configured for receiving a guide pin. The second hole on the detent bar may be configured as an elongated slot for receiving a guide pin that mounts the detent bar to the frame assembly, and the elongated slot may be longer than a diameter of the guide pin along at least one direction to permit movement of the guide pin within the slot along that at least one direction.
In another presently preferred aspect, an explosion resistant cargo container suitable for aircraft or seagoing vessels for containing the effects of a bomb explosion within the cargo container, includes a frame assembly; a plurality of panels mounted to the frame assembly, the plurality of panels including a top explosion resistant panel, a bottom explosion resistant panel, a plurality of explosion resistant side panels, and an explosion resistant flexible door panel having two side edges and a bottom edge, the two side edges of the flexible door panel mating with corresponding edges of side panels of the container including an outboard doorpost and an inboard doorpost, and the bottom edge of the flexible door panel mating with a corresponding bottom door sill, the side panels and flexible door panel each being formed of a plurality of explosion resistant sheets, each sheet of said plurality being formed of an explosion resistant, flexible, high tensile strength material, the plurality of explosion resistant sheets having edges that are wrapped around and secured to an edge rod; an edge capturing rail segment wrapped around each plurality of explosion resistant sheets over each edge rod, securing adjacent edges of the panels together; and a plurality of fasteners, each fastener extending through two or more panels and an edge capturing rail segment.
Other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments in conjunction with the accompanying drawing, which illustrates the construction of a lightweight laminated panel material for construction of cargo containers, according to the invention.
Referring to the drawings, which are provided by way of example, and not by way of limitation, an explosion resistant cargo container 2 suitable for aircraft or seagoing vessels for containing the effects of a bomb explosion within the cargo container, includes a frame assembly 4 and a plurality of panels 6 mounted to the frame assembly. The plurality of panels 6 include a top explosion resistant panel 8, a bottom explosion resistant panel 10, a plurality of explosion resistant side panels 12, and an explosion resistant flexible door panel 14 having two side edges 16, 18 and a bottom edge 20. The side panels 12 and flexible door panel 14 are each formed of two or more explosion resistant sheets, each sheet 22 being formed of an explosion resistant, flexible, high tensile strength material. The explosion resistant sheets 26 have edges 28 that are each wrapped around 30 and secured to an edge rod 34, as shown in
At each corner 46 of the container 2, a second 48 edge capturing rail segment on a second side 50 of the container may be oriented in an approximate position of a first 52 edge capturing rail segment on a first side 54 of the container but rotated by 180 degrees, as shown in
In regard to
With regard to the frame assembly 4 or skeletal structure for the container as shown in
The container 2 also includes a latch 68, as shown in
With regard to
The latch 68 may include a detent bar 74 as illustrated in FIGS. 5 and 11-15. Detent bar 74 is configured to lock the locking rail segment 70 of the two side edges 16, 18 and the bottom edge 20 of the flexible door panel 14 within the corresponding hook 72 of the latch 68 on the outboard doorpost 62, the inboard doorpost 64, and the bottom door sill 66, respectively. This locking may be accomplished, in part, through a plurality of protruding teeth 78 or other extensions of the detent bar 74 configured to be received in corresponding slots 80 of the outboard doorpost 62, the inboard doorpost 64, or the bottom door sill 66 of the frame assembly 4.
As shown in
Outside of the container 2, a handle 76 on the latch 68 can be manipulated to release the secured door panel 14 along each of the three free edges 16, 18, and 20. For example, the handle 76 may be manipulated by rotating it as suggested in
As shown in
The two doorposts 62, 64 and the door sill 66 (shown in
Each blast resistant panel 6 is made of multiple layers or sheets 26, each layer or sheet 22 formed of a high strength woven material and bonded together with adhesive films. The edge of the panel wraps around a cylindrical rod 34 and is bonded to the rod as well as itself with adhesive, forming a folded edge much like a corded hem, as shown in
The joining edges 42 of two neighboring panels overlap one another with both of the first and second edge capturing rails 52, 48 nestling against the panels opposite to one another as shown in
This unique panel connection design is particularly advantageous for resisting blast load impulses owing to the resist-slip-resist feature. When the tensile load in the panel reaches a certain magnitude which can overcome the holding power of the edge capturing rail 36, the rod embedded edge of the panel will slip out of the groove in the rail, dissipating blast energy along the way. As the joining panels continue to stretch at their adjacent edges 42, the connection takes up the load by wedging the rod embedded panel edge between the two edge capturing rails 48, 52 which are held firmly together by the fasteners 44 (see
The flexible door panel 14, as seen in
Referring to
With regard to FIGS. 5 and 11-17, the latching mechanism includes a handle 76 and a lever 96 having a common pivot point 108, but both are able to rotate independently of each other through some portion of the rotation. There are two activation pins 106 on the handle 76 which come in contact with the lever 96 when the handle reaches a certain angle, thereby forcing the lever to rotate with the handle. As the handle and the lever continue to rotate, the cam roller 102 attached to the lever 96 pushes the detent bar 74 and forces it to slide against the guide pins 88. When the detent bar 74 is fully extended, the locking rail segments 70 along the door edge are fully trapped, as shown in
The flexible door panel 14 shown in
As shown in
FIGS. 5 and 11-15 show the details of the latching mechanism.
In regard to
As shown in
Suitable blast resistant panel materials and constructions include but are not limited to woven materials made from aramid, UHMW polyethylene, liquid crystal polymer, polyvinyl alcohol, polyhydroquinone-diimidazopyridine (M5), poly(p-phenylene-2,6-benzobisoxazole) (PBO), carbon, glass, polypropylene, or polyamide fibers. Suitable adhesives include film adhesives made from polyolefin, urethane, ionomer, or ethyl vinyl acetate thermoplastics and film adhesives made from epoxy, phenolic, or vinyl ester thermosets. One or more ply or layer of the woven materials and adhesives may be used for each panel. Suitable materials for the embedded edge rod include but are not limited to plastics or composites, or metals such as aluminum or magnesium. Suitable materials for the edge capturing rail include but are not limited to extruded or roll-formed aluminum or magnesium rails. Suitable materials for the frame structure include but are not limited to extruded or roll-formed aluminum or magnesium rails and composite protrusions.
The blast resistant container constructed in accordance with the principles of the present invention has successfully passed the cargo blast test in accordance with the requirements set forth in “Classified Addendum to TSO-C (HC-R) Draft Appendix A” issued by the Department of Homeland Security.
One specific example of the benefits provided by the blast resistant cargo/baggage containers in accordance with the present invention is the ability to more safely transport batteries and contain any explosion thereof. For example, especially the larger batteries used for personal laptop computers and clean energy vehicles increase the risk of an explosion, burning, or leakage during transit. Various embodiments of the present invention permit contemporary batteries to be transported safely while minimizing the risk of any incidents impacting other goods in transit being carried nearby the batteries.
Another specific example of the benefits provided by blast resistant cargo/baggage containers in accordance with the present invention is the ability to guard against terrorism in the form of explosives concealed in luggage that slip through airport security to arrive onboard in the stowage compartment. Civil aviation has been one of the prime targets of terrorist attack. The blast resistant cargo/baggage container has been identified as an effective means of improving the survivability of commercial aircraft in a blast event caused by an explosive device hidden in baggage or cargo.
It will be apparent from the foregoing that while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
The invention was made with Government support under Contract No. HSHQDC-09-C-00052 awarded by the Transportation Security Laboratories of the Department of Homeland Security. The Government has certain rights in the invention.
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Number | Date | Country | |
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20140008358 A1 | Jan 2014 | US |