The invention relates to methods and apparatus for controlling hazardous and/or flammable materials and the effects of such materials.
Flammable and otherwise hazardous materials play an important role in the everyday lives of most people. Most people encounter flammable materials, such as gasoline, engine oil, and natural gas, and other hazardous materials, such as battery acid and concentrated detergents, without danger. Because the unsafe materials are contained, they typically present no problem for those that are nearby.
When the unsafe materials become uncontained, however, the materials can injure or kill, such as when the container is damaged and the material escapes. For example, hundreds of thousands of vehicular accidents occur each year on American highways. Many accident-related fire events occur when the region of the vehicle containing the fuel tank is impacted in an accident, spilling the fuel contents from the tank in the form of a spray, stream, and eventual pool around the vehicle. The highly ignitable spray mist generated upon impact may be exposed to ignition energy from sparks generated from vehicle deformation on impact for only a fraction of a second. This duration, however, may be long enough to ignite the fuel mist into a possible explosion, or more likely a fireball that ignites a developing pool of fuel surrounding the vehicle and create a more serious threat.
In many cases, the threat of ignition and resultant flame spread only exists for the instant that the sparks from the impact event remain. These events have been noted particularly on several recent automotive and truck designs that were hypothesized, due to tank placement and structural design, to have potentially higher rates of incidences of such events. These high profile examples often lead to spectacular fire events and the higher rates of burn injuries and fatalities when they occur, and have resulted in national discussions on how to prevent their continued occurrence.
Unfortunately, most fire protection technologies are impractical for general highway vehicle or other consumer use, due to cost, complexity, reliability problems, and substantial weight increases. As a result, little has been done to prevent such events in the future. The military, however, has confronted similar events that occur in combat scenarios. In particular, military aircraft that are impacted by anti-aircraft projectiles can develop fires in adjoining bays adjacent to fuel tanks onboard the aircraft. The fuel leaking or spraying from a penetrated tank encounters ignition sources, such as burning incendiary particles deposited by the projectile in the adjoining bay, with resultant fires threatening the interior of the aircraft. Many aircraft losses in combat have been attributed to such events.
As a result, technologies have been developed in recent decades to prevent or suppress such events for newer combat aircraft. One approach to aircraft fire protection uses passive systems. These systems are typically some form of structure that requires no electrical power or other artificial monitoring. These systems function by being impinged directly by the explosion or fire event. They typically provide explosion protection inside the fuel tank or in surrounding compartments around the fuel tank. One of the earliest and most successful variants was the use of flexible reticulated foam in fuel tanks to mitigate explosions. This concept was extensively used successfully in the latter stages of the Vietnam War and became a fixture on many modern era aircraft.
The British military developed several advanced concepts in the early 1970s. These included forming reticulated foam into balls to fill various compartments adjacent to fuel tanks in aircraft (U.K. Patents 1,380,420, 1,445,832, and 1,454,492) that could be coated with substances that swell upon heating to cut off air supply to the fire, and filled with various gaseous and powder extinguishing agents to provide extra fire extinguishing in addition to fire mitigation. The main advantages of such concepts were ease of installation, high reliability due to lack of sophisticated electronics and other devices, and competitive weight penalties in comparison to active fire suppression systems, such as gaseous fire extinguishing and detection systems, with the trade-off depending upon the compartment volume and configuration.
Other passive protection systems use fire suppressants embedded into rigid or semi-rigid panels mounted onto the wall of the fuel tank adjoining and facing an adjacent bay. The panels, when impacted by a projectile penetrating through the aircraft, would rupture locally and release a portion of suppressant into the adjacent bay, extinguishing the beginnings of fuel spray from the damaged fuel tank entering the bay and igniting, or rendering the fuel vapors inert against ignition when coming into contact with the deposited incendiary particles. The panels were developed and demonstrated with gaseous extinguishing agents and various powders (U.K. Patents 1,454,493 and 1,547,568). The panels took the form of hollow panels with cylinders or sachets of suppressant inserted, or balls or sheets of reticulated foam (sometimes sealed in bags with a pressurized gaseous suppressant).
All of these variations showed some level of performance enhancement for a given system volume or weight, but could be offset by increased complexity or increased material, assembly, or installation cost. The most common and simple variations were thin panels with a hexagonal honeycomb sandwich material of kraft paper, aluminum, or Nomex, filled with a fire extinguishing powder and covered with a thin sheet on both faces of aluminum foil, composite fibers, or other materials. These devices were described as powder panels or powder packs.
The powder panels were demonstrated to effectively protect against many large ballistic incendiary threats with as little as 0.1 inch total thickness and 0.2-0.6 pounds mass per square foot. Other threats and conditions could require much thicker, heavier, systems if they worked at all. Some limitations in performance were seen against small threats that limited rupture damage to the panel and as a result limited the amount of powder suppressant released to extinguish the fire.
Variations of this concept were investigated for use against ballistic impacts in armored vehicles (U.S. Pat. Nos. 3,930,541 and 4,132,271), although powders were primarily limited for use in engine compartments due to the inhalation difficulties with crew members, and gaseous suppressant filled panels were used in the crew compartment. Later fine tuning was made including adding spall shields to prevent spallation damage from the panels to crew members.
Since these systems require ballistic impact to function, their utility and consideration was limited to combat-induced ballistic impact events; they offer no protection against gradual fuel system leakage and ignition due to ordinary fuel system failures. Further, such systems do not provide protection against other types of threats or problems. For example, such systems do not provide protection in other fire scenarios, such as collisions impacting and fracturing fuel tank valves and their connectors, particularly for alternate fueled vehicles. Additional flammable fluid reservoirs, such as brake master cylinders and fuel pumps, contain sufficient flammable fluid to pose a threat to vehicle occupants or the vehicle itself, and their small, bulky shapes provide difficulties in providing protection. Other areas of a vehicle, such as the vehicle's engine compartment hood, exhibit damage in front end crashes, and may cause the release of flammable or otherwise hazardous materials. Further, some components, such as the oil pan, may rupture and discharge flammable fluids due to the internal destruction of the engine, which is typically accompanied by the fracturing and penetration of the connecting rods through the oil pan. This scenario is very common in automobile racing in addition to highway occurrences.
A hazard control system according to various aspects of the present invention comprises a housing configured to contain a control material and deliver the control material to neutralize a hazard in response to a trigger event. In one embodiment, the control material is an extinguishant for retarding fire. The housing contains the extinguishant and includes at least one surface configured to rupture in response to a trigger event, such as an impact. The housing may also include a surface configured to substantially mate with a surface of a vehicle, such as a fuel tank surface.
A more complete understanding of the present invention may be derived by referring to the detailed description when considered in connection with the following illustrative figures. In the following figures, like reference numbers refer to similar elements and steps.
Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present invention.
The present invention is described partly in terms of functional components and various processing steps. Such functional components may be realized by any number of components configured to perform the specified functions and achieve the various results. For example, the present invention may employ various elements, materials, suppressants, neutralizing agents, and the like, which may carry out a variety of functions. In addition, the present invention may be practiced in conjunction with any number of applications, environments, hazardous materials, and trigger events, and the systems described are merely exemplary applications for the invention. Further, the present invention may employ any number of conventional techniques for manufacturing, assembling, mounting, and the like.
Referring now to
The housing 102 may comprise any suitable apparatus for containing the control material 104 and facilitating dispersal of the control material 104 in response to the trigger event. For example, the housing 102 may comprise a container configured to shatter, explode, or otherwise deteriorate, either entirely or in part, upon impact to release the control material 104. In various embodiments, the housing 102 may comprise a rigid structure, a semi-rigid structure, a membrane, or a bladder. The housing 102 may be comprised of any suitable materials, for example glass, ceramic, or plastic that is designed to shatter upon impact. Further, the housing 102 may be configured to promote dispersal of the control material 104, for example by scoring the housing 102 to promote fracturing of the scored surface in the event of an impact. The housing 102 may include additional mechanisms for promoting dispersal of the control material 104, such as one or more spring mechanisms, such as a leaf spring, compressed coil spring, a flat spring, an expandable material, configured to enhance the expansion of the housing 102 when the housing 102 is weakened or fractured by the trigger event. In one embodiment, multiple channels formed in the housing 102 include spring mechanisms to biased against a surface of the housing 102 to be impacted.
In the present embodiment, the housing 102 suitably comprises two face sheets 106 sandwiching the control material 104. The face sheets 106 maintain the control material 104 in position, and may comprise any suitable configuration, such as a rigid sheet, a flexible cover, a flexible bladder, or any other appropriate system for maintaining the control material 104 in a selected position. Further, the face sheets 106 may comprise any appropriate materials, including cellulosic material such as styrene, paper, glass, plastic, metal, ceramic, aluminum, nylon, glass fabric, fiberglass/epoxy, Kevlar, graphite tape, or a composite or combination of such materials. The face sheets 106 are suitably configured to react to a trigger event, such as an impact, a thermal event such as exposure to heat, or an optical event such as exposure to particular radiation. In the present embodiment, the face sheets 106 are suitably configured to substantially completely shatter or otherwise rupture to promote total release of the control material 104. The housing 102 may also comprise malleable materials, so the housing 102 may be shaped and bent to fit various configurations. In the present embodiment, the face sheets 106 are rectangular sheets constructed of a lightweight and cost effective material, such as glass, ceramic, acrylic, and/or epoxy.
The face sheets 106 are suitably mounted on a frame 108 to support the face sheets 106. The frame 108 may comprise any suitable structure, such as a rigid structure joined to the face sheets 106, an adhesive material like a caulk between the face sheets 106, or a rigid spacer. In an alternative embodiment, the frame 108 may be omitted and the face sheets 106 may be otherwise configured to maintain the position of the control material 104. For example, the ends of the face sheets 106 may be taped adhesively, glued, or crimped, or the face sheets 106 may be formed as a single unit, such as using blow molding, vacuum forming, or thermoforming to form the housing 102.
In the present embodiment, the frame 108 is configured to support the face sheets 106 and maintain the control material 104 in position. For example, the frame 108 suitably comprises a rigid structure having the same shape as the face sheets 106 and bonded to the face sheets 106. Thus, in the present embodiment, the frame 108 comprises a rigid rectangular frame 108 configured to support the face sheets 106. In addition, the face sheets 106 may be connected to the frame 108 in any suitable manner, for example using fasteners or a bonding agent. In the present embodiment, the face sheets 106 are bonded using an epoxy 110 or a similar adhesive. Other variations may be used to bond the face sheets 106 to the frame 108, such as hot glues and other chemical adhesives.
The housing 102 may also include a core 112 configured to separate the control material 104 into multiple compartments. The core 112 may also maintain a desired space between the face sheets 106 and support the face sheets 106. The core 112 may be configured in any suitable manner. In the present embodiment, the core 112 may be configured in a honeycomb configuration to form individual compartments. In addition, the core 112 may comprise any appropriate materials, such as lightweight, rigid materials. In the present embodiment, the core 112 comprises aluminum or Nomex.
The housing 102 contains the control material 104. In the present embodiment, the control material 104 is contained in the compartments formed by the core 112. The control material 104 may comprise one or more suitable materials for neutralizing a particular hazard, such as a fire, acid spill, or noxious gas release. For example, to extinguish a fire, the control material 104 may comprise a fire suppressant, such as monoammonium phosphate, mixed with an appropriate desiccant and/or flow enhancer such as a 1% concentration of micronized fumed silica. Alternatively, the suppressant may comprise sodium bicarbonate, potassium bicarbonate, potassium carbonate, urea-based powders, potassium dawsonite, ammonium polyphosphate, monoammonium phosphate, potassium iodide, or other powder suppressants or mixtures, or liquid or gaseous agents, such as water, nitrogen, carbon dioxide, argon, iodotrifluoromethane, heptafluoropropane, pentafluoroethane, or other gaseous agents or mixtures.
The compartments of the core 112 are suitably totally filled to capacity, though some settling may occur after construction and installation, leaving some void space in the core 112. If the compartments are not completely full, the control material 104 may be supplemented with a filler, such as a neutral, non-burning substance to occupy internal volume. In the present embodiment, the filler is configured to cover a large area while adding little weight. The filler may comprise, for example, silica dessicant, glass or plastic microspheres which may be filled with the control material 104 or remain empty, or other suitable lightweight material.
In addition, the control material 104 may be enhanced to facilitate dispersal and/or react to the trigger event. For example, the control material 104 may be pressurized, for example with air, a gaseous control material 104, or other fluid to enhance dispersal of the control material 104. Further, the control material 104 may respond directly to the trigger event. For example, the control material 104 may include an optically reactive, thermally reactive, or impact reactive material that causes the control material 104 to expand or otherwise deploy.
The control material 104 may also be supplemented with or include a propellant to propel the control material 104 out of the housing 102 to enhance delivery. For example, the control material 104 may be supplemented containers of gas, such as ambient or pressurized air or a fire suppressant gas, that when compressed by the impact, burst and provide a gust of air to help disperse the control material 104. The containers may comprise any suitable containers, such as enclosed tubes or balls of thin plastic or other suitable material. Alternatively, the propellant may comprise a material that, when exposed to air, generates an expanding volume of gas to propel the control material 104. The propellant may also comprise a fire suppressant material, such as carbon dioxide. Alternatively, the propellant may include different areas of the housing 102 that may contain separate materials. When the materials react to the trigger event, such as in response to heat or by mixing following rupture of the housing 102, the materials may react to generate a propelling gas and, in some embodiments, a supplemental fire suppressant. For example, the materials may comprise acetic acid and a sodium bicarbonate control material 104, which produces carbon dioxide when mixed. Alternatively, the material may comprise carbonic acid, which reacts to heat, such as due to a fire, by decomposing to water and carbon dioxide. Other materials may be used that create carbon dioxide and water when mixed, such as calcium carbonate and hydrochloric acid, or sodium carbonate and dilute sulfuric acid. Yet other materials may produce a fire suppressant foaming agent. For example, the supplementary material or control material 104 may comprise sodium bicarbonate powder with a licorice additive, which mixed with aluminum sulfate will make a sticky, aluminum hydroxide foam. Other materials may comprise compositions of nitrogen triiodide or nitrogen tribromide powders or solids, possibly mixed with stabilizing binders, which when impacted convert to nitrogen gas and fire suppressing iodine or bromine gas.
The hazard control system 100 may be attached to or integrated into a hazard source, such as a fuel tank or other hazardous material storage unit in a vehicle, such as a car, bus, truck, aircraft, racing car, police car or van, military vehicle or craft, racing boat, rail car, tractor trailer, or heavy equipment. For example, referring to
The hazard control system 100 may be configured in any suitable manner for a particular application, such as to enhance or direct dispersal of the control material 104, facilitate adaptation to multiple applications, reduce weight and/or cost, fit to particular objects, mitigate one or more different hazards, and the like. Referring to
In the present embodiment, the channels 610 are formed by raised partitions formed on an interior surface of at least one of the face sheets 106. Consequently, no core 112 is included. Alternatively, the housing 102 may include the core 112 to form the channels 610, and the frame 108 may also include structure, such as protruding partitions or other suitable structure, to form all or part of the channels 610.
In addition, the channels 610 may be formed in any appropriate manner to maintain the position of the control material 104, facilitate dispersal of the control material 104 upon occurrence of the trigger event, provide ease of manufacturing and/or installation, or any other purpose. In the present embodiment, the channels 610 are configured to form individual parallel channels 610. Alternatively, the channels 610 may be configured in a serpentine pattern, diagonal channels 610, a combination of diagonal, horizontal, vertical, and/or otherwise oriented channels 610.
Further, the channels 610 may run in any suitable direction, and may be interconnected. For example, referring to
The housing 102 may also include structural components to provide rigidity, such as ribs formed in the housing 102. In addition, the face sheets 106 may be joined by an adhesive 1114 that has limited bond strength, sufficient only for normal operational environments. The limited strength of the adhesive suitably provides minimal impedance to crack propagation of the second face sheet 1112, facilitating separation of the second face sheet 1112 (in its entirety or in pieces) from the partitions 1010.
To enclose the housing 102, the housing 102 edges may be sealed, for example using tape or caulk. Referring to
The housing 102 may include any appropriate materials to facilitate response to the trigger event, provide manufacturing efficiency, reduce weight, or satisfy any other appropriate criteria. For example, referring to
An alternative embodiment of the housing 102 includes multiple compartments for containing the control material 104. Each compartment may be fully enclosed or connected to one or more other compartments. For example, each compartment may be fully enclosed and individually filled with the control material 104. Alternatively, a compartment may be connected to another compartment so that both compartments may be filled by accessing a single compartment. Using multiple compartments suitably facilitates cutting the housing 102 to a selected size.
For example, referring now to
In the present embodiment, the housing 102 comprises two face sheets 106A-B. At least one of the face sheets 106A includes multiple indentations to form the compartments 1210. For example, the second face sheet 106B may be flat and the first face sheet 106A may be configured to include multiple indentations in the form of the compartments 1210. The compartments 1210 are suitably formed in rows parallel to a longitudinal axis of the face sheets 106.
The two face sheets 106 are joined in any suitable manner so that the second face sheet 106B covers the indentations in the first face sheet 106A to form the compartments 1210. The compartments 1210 may, however, be formed in any suitable manner, such as by indentations in the second face sheet 103B, compartments formed by the core 112, independent bladders, a quilted bladder having multiple pockets, and the like.
The compartments 1210 of the present embodiment are suitably connected to allow control material 104 to flow between the interconnected compartments 1210. The compartments 1210 may be interconnected in any suitable manner, such as via openings 1212 formed along one or more sides or other surfaces of the compartments 1210. Further, the openings 1212 may be connected in any suitable manner, for example via one or more ducts 1214 connecting the openings 1212. The connections between the compartments 1210 may be implemented in any appropriate manner, such as using tubes attached to the compartments 1210, indentations in one or both of the face sheets 106, inclusion of a core 112 including the ducts 1214, and the like. In the present embodiment, the ducts 1214 are formed by indentations formed in the first face sheet 106A adjacent the indentations used to form the compartments 1210.
In addition, the housing 102 may include any other desired structures to lend desired characteristics to the housing 102, such as to add stiffness, provide mounting surfaces or mechanisms, and the like. For example, in the present embodiment, the first face sheet 106A may include rectangular indentations 1216 formed between the duct indentations 1214 to reduce the surface-to-surface contact between the face sheets 106 and promote crack propagation.
In the present embodiment, each compartment 1210 along two edges of the housing 102 has at least one opening 1212 in one side which is connected to a duct 1214. Each compartment 1210 in the interior of the housing 102 and along the other two edges of the housing 102 has two openings 1212 on opposite sides of the compartment 1210. The openings 1212 are connected to the openings 1212 of the other compartments 1210 via the ducts 1214 to form connected compartments. Consequently, the control material 104 may move between the compartments 1210 through the openings 1212 and ducts 1214. Referring again to
The hazard control system 100 may be configured for a selected environment, a selected hazard, and/or a selected trigger event. For example, the hazard control system 100 may be adapted for use with vehicle fuel tanks, storage tanks, fuel or chemical transfer lines, connectors, valves, and other components, oil containers and oil pans, battery compartments, engine compartments, or other applications. In addition, the hazard control system 100 may be configured to control flammable materials, toxic materials, caustic or corrosive materials, or other harmful materials. Further, the hazard control system 100 may be configured to respond to any suitable trigger event, such as an impact, exposure to heat, exposure to a particular substance, or detection of a hazardous condition.
For example, the hazard control system 100 may be specifically configured for particular applications by shaping the housing 102 to conform to a selected surface. For example, referring to
Referring to
The housing 102 may be configured in any suitable manner to contain the control material 104, such as a fire suppressant, and shatter upon impact to release the control material 104. In the present embodiment, the housing 102 includes partitions formed in at least one of the face sheets 106 to form the compartments 1210 and suitably the ducts to interconnect the compartments 1210 as shown in
Referring to
In an alternative embodiment, the hazard control system 100 may be configured for adaptation to any particular application using one of more housings 102. For example, multiple housings 102 may be attached to a fuel tank 514 or other structure to facilitate hazard mitigation. In addition, the housings 102 may be cut to a selected size and/or shape for a particular application.
For example, referring again to
To cut the length, a length of the housing 102 may be cut away (
The hazard control system 100 may be attached to or associated with a hazard source in any appropriate manner. In various applications, the hazard control system 100 may be placed adjacent to or above the hazard source. Alternatively, the hazard control system 100 may be attached to or abut the hazard source. Any appropriate system or mechanism may fix the hazard control system 100 in position. For example, the housing 102 may be adhesively attached directly to the fuel tank 514, such as via a peel-and-stick adhesive tape. The housing 102 may also be attached to other areas in proximity of the fuel tank 514, such as the inside of the vehicle body panels, and can be attached by any other suitable mechanism, such as tape, straps, rivets, clips, hook-and-loop fasteners, or other fasteners.
In another embodiment, the hazard control system 100 may be adapted for a particular component that may be susceptible to causing a hazard. For example, referring to
The housing 102 is suitably configured such that when the fuel pump 1510 is impacted sufficiently (such as in an accident) to break off or partially disconnect the fuel pump 1510 from the engine, facilitating the discharge of its flammable fluid contents and its subsequent ignition, the housing 102 should also break apart due to the same impact, releasing a cloud of suppressant around the region of fluid discharge to mitigate ignition and any resultant fires. The hazard control system 100 may be similarly adapted for other reservoirs and components, including superchargers and turbochargers, power steering pumps, vapor canisters, brake master cylinders, oil pumps, washer fluid reservoirs, fuel pressure reduction valves, and other valves attached to fluid vessels such as those on compressed natural gas (CNG) tanks, liquefied petroleum gas tanks (LPG), hydrogen tanks, and other alternate fueled vehicles.
The hazard control system 100 may also be adapted to fluid lines and connectors to control hazards in the event of the trigger event. For example, referring to
The present embodiment also suitably includes a washer 1616 attached to the fluid line 1612. In addition, scored fracture lines 1618 may also be added to the outer faces of the ring 1610. If an event occurs that results in the pulling of the fluid line 1612 sufficiently as to separate it from the reservoir 1614 (such as due to a collision), then the washer 1616 (attached to the fluid line 1612) pulls through the ring 1610, rupturing the ring 1610 and dispersing the control material 104 around the surrounding area to suppress the hazard, such as ignition of fluid discharging from the disconnected line in the local area.
The hazard control system 100 may be further configured for controlling hazards at the coupling of two fluid lines 1706. For example, referring to
If the two ends of the fluid line 1706 are pulled apart (such as due to a collision) and disconnect at the site of the coupling 1714, the flange 1716 of either fluid line 1706 (or both) pulls through the panel disks 1708A-B and shatters them and the control material 104 is released at the same time to inhibit the relevant hazard, such as the ignition of any fluids discharged from the disconnecting lines. The adhesive force between the faces of the disks 1708A-B is designed to be stronger than the force required to fracture either disk 1708A-B by a flange 1716 on either line, to assure that disk fracturing occurs.
In another alternative embodiment, the hazard control system 100 may be adapted for controlling a hazard in the event of damage to an oil pan. Referring to
In another embodiment, the hazard control system 100 may be configured for controlling hazards in an engine compartment. The hazard control system 100 is suitably configured to diminish a hazard in the event the engine compartment is damaged or another trigger event occurs. For example, the hazard control system 100 may be configured to inhibit fire in the event the engine compartment of a convention automobile is damaged, such as in a front-end collision. Referring to
In such a front impact 1910 of a vehicle 1912, the vehicle hood 1914 is configured to deform as normally designed, forming a crease 1916 along a pre-set failure line. In the present embodiment, the housing 102 comprises a hood liner 1918 containing the control material 104, such as a fire extinguishing chemical, for example a dry chemical powder, and formed to the general shape of the underside of the hood 1914. The liner 1918 may have surface coverings to feature sound dampening, or have special sound dampening material added between the liner 1918 and the hood 1914.
When the hood 1914 deforms in a collision, the liner 1918 also deforms until it fractures. The liner 1918 may also include scored lines formed on the surface of the liner 1918 to assist in the breakup of the liner 1918. The control material 104 within the liner 1918 is discharged down onto the engine compartment to prevent any fires or other relevant hazard that might result from the discharge of flammable or otherwise hazardous materials.
In another alternative embodiment, the hazard control system 100 is configured to respond to a thermal trigger event. The trigger event may comprise any appropriate thermal trigger event, such as a sudden rise in temperature or a temperature above a selected threshold. For example, referring to
The housing 102 is configured to crack and fracture upon exposure to thermal stresses above a selected threshold, such as from a pool fire a few inches from it. For example, the housing 102 suitably includes a bottom face sheet facing the ground constrained by a rigid frame 108 on its perimeter. The face sheet 106 suitably has a higher thermal rate of expansion than the frame 108, such that when the housing 102 is exposed to heat above a selected threshold, the frame 108 restrains the thermal expansion of the bottom face sheet, thus causing stress within the panel to cause its cracking and rupture. Stress can be applied via pre-loading the panels in the frame 108 or by other heat treatments such that minimal additional thermal stresses are required to achieve the fracture condition. Alternatively, the face sheet 106 may melt, peel back, or otherwise move aside upon exposure to heat above a selected threshold. Further, the control material 104 may be configured to swell upon exposure to heat above the selected threshold to cause or supplement the cracking and rupture of the face sheet 106.
If the housing 102 is integrated into a pre-formed fuel tank, for example in conjunction with an outer shell filled with the control material 104, the face sheet 106 to rupture may be pre-loaded by controlling of the forming and post-heating processes. Such techniques may be applied to plastic tanks that are molded and are in abundant use today, but which may be particularly vulnerable to failure when exposed to pool fires established underneath them.
The hazard control system 100 may also be adapted for use in conjunction with nonflammable hazards, such as an enclosure that houses batteries that may be used on an electric vehicle. If such a container is ruptured, such as due to a collision, and the enclosure is ruptured as well as the batteries, caustic and corrosive battery acids can be released to the environment. Such acids pose a hazard to the vehicle occupants, the environment, rescue personnel, and those hired to inspect the wreckage and transport it to a safe area.
A hazard control system 100 according to various aspects of the present invention may be configured for any application where a caustic, corrosive, toxic, or otherwise harmful chemical may be unintentionally released, such as due to a vehicle collision or accident, including tractor-trailers and other transport vehicles that haul such caustic and dangerous chemicals in large quantities. Alternatively, the hazard control system 100 may employ a housing 102 covering or adjacent to the single battery used on virtually all vehicles to inhibit excessive damage resulting from a potential leakage or spray of battery acid within the engine compartment, or toward operators if the battery is damaged in a collision or explodes due to other damage to the battery.
Referring to
The various components of the hazard control system 100 may be formed according to any appropriate technique or method. For example, the housing 102 and the core 112 may be cut, cast, extruded, machined, stamped, molded, or otherwise formed to configure to the desired shapes. For example, the housing 102 is suitably vacuum molded, injection molded, or blow molded to form a desired configuration, such as to conform the housing 102 to a particular shape like the exterior of a particular vehicle fuel tank. In particular, the face sheets 106 may be molded so that one exterior surface conforms to the external surface of the fuel tank and the second exterior surface fits within the fuel tank compartment. To form two separate face sheets 106 to be joined with an adhesive, the face sheets 106 are suitably vacuum molded. To form a single integrated housing 102, the housing 102 is suitably blow molded.
In addition, a core 112 may be formed, for example by extrusion. Alternatively, the compartments, channels 610, or other interior structure of the housing 102 may be generated by forming the interior surface of one or more face sheets 106, for example during the molding of the face sheets 106. The face sheets 106 may then be joined to form the housing 102, suitably surrounding the core 112, if desired. If the ends are sealed using end caps, the end caps may be attached, for example after insertion of the control material 104.
The housing 102 is suitably formed of a plastic or other material that may exhibit a grain, or a tendency to more easily crack or shatter in a particular direction. To enhance shattering of the housing 102, the interior structure of the housing 102, such as the core 112, the channel partitions 1010, rows of compartments, or the like, may be configured to extend perpendicularly to the grain. Because the interior structure may tend to support the integrity of the housing 102, extending the interior structure perpendicular to the grain of the housing 102 material may facilitate easier and/or more extensive shattering of the housing 102. Orienting the grain perpendicular to the channels 610 promotes opening of multiple channels or compartments to discharge more control material 104, as the cracks tend to propagate along the grain across multiple channels or compartments.
The control material 104 may be added in any suitable manner, such as before joining the housing 102 components or after assembly of the housing 102. For example, the control material 104 may be added by standing the housing 102 upright and resting on one end and pouring the control material 104 into the upper end of the housing 102. Alternatively, the control material 104 may be added to the individual compartments or channels 610 in any other appropriate manner, such as by inserting the control material 104 directly into each channel or compartment, for example if the compartments or channels 610 are not interconnected. The control material 104 can be poured, injected under pressure, or otherwise inserted into the channels 610.
The access openings for adding the control material 104 are then suitably closed. If the housing 102 uses end caps, the end cap 810 can be snapped into position, substantially sealing the housing 102. Any other relevant system for maintaining the control material 104 within the housing 102 may be implemented, such as sealing the openings with caulk, putty, plugs, membranes, tape, or other mechanism. The hazard control system 100 may then be attached to the relevant hazard source.
The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the present invention in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in a practical system.
The present invention has been described above with reference to a preferred embodiment. However, changes and modifications may be made to the preferred embodiment without departing from the scope of the present invention. These and other changes or modifications are intended to be included within the scope of the present invention.
This application: is a continuation of U.S. Nonprovisional patent application Ser. No. 10/728,223, filed on Dec. 3, 2003 now abandoned, which claims the benefit of U.S. Provisional Patent Application No. 60/430,912, filed Dec. 3, 2002; is a continuation-in-part of U.S. Nonprovisional patent application Ser. No. 09/920,179, filed Aug. 1, 2001 now abandoned; and is a continuation-in-part of U.S. Nonprovisional patent application Ser. No. 10/443,302, filed May 21, 2003; and incorporates the disclosure of each application by reference.
Number | Name | Date | Kind |
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4121666 | Rozniecki | Oct 1978 | A |
4132271 | Mikaila | Jan 1979 | A |
4251579 | Lee et al. | Feb 1981 | A |
4502815 | Scales et al. | Mar 1985 | A |
5762145 | Bennett | Jun 1998 | A |
Number | Date | Country | |
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20070068686 A1 | Mar 2007 | US |
Number | Date | Country | |
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60430912 | Dec 2002 | US |
Number | Date | Country | |
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Parent | 10728223 | Dec 2003 | US |
Child | 11423647 | US |
Number | Date | Country | |
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Parent | 09920179 | Aug 2001 | US |
Child | 10728223 | US | |
Parent | 10443302 | May 2003 | US |
Child | 09920179 | US |