Patent Publication Number: US-2010122824-A1

Title: Portable Fire Retardant Application Apparatus

Description:
FIELD OF THE INVENTION 
     This invention relates to apparatus designed to apply fire retardant to specific sites, typically in an effort to protect structures from wildfire and/or to control wildfire behavior and direction, and more specifically, to a portable fire retardant application apparatus for distributing fire retardant in desired areas around and on the exterior surfaces of structures when needed, or in specific areas to impede wildfire progress. 
     BACKGROUND 
     In recent years numerous wildfires, particularly in the Western regions of the United States, have destroyed thousands of homes and other structures. While these fires have been concentrated primarily in the Western states, the risk from wildfire to residences exists throughout the U.S. and in other parts of the world. 
     Over the past several decades there has been an increasing migration of population from cities and towns toward rural areas, and there has been a dramatic increase in the number of homes and communities being built at the interfaces between urban and forest lands—the so-called “urban-wildland” interface. As more homes and communities are built along the boundaries between urban and forested areas, and particularly in areas that are historically burned by wildfires, more and more of these structures are directly exposed to the risks of destruction by wildfires. This population and construction trend, coupled with historical timber management practices that have led to increased forest fuel loading in recent years, and drought conditions existing across the Western U.S. have led to an unprecedented number of structures being in danger of exposure to wildfires. 
     Conventional methods of fighting wildfires often have little impact when the fires enter the urban-wildland interface where residential subdivisions have been built, and wildfire fighters often can only stand back and watch as homes in the path of a wildfire are destroyed. The inability to prevent wildfire from destroying communities has been seen dramatically in the past several years, during which several highly publicized wild fires destroy thousands of homes in throughout the West, including Colorado, California, Nevada, Utah and other states. 
     The costs of fighting wildfires can be enormous. During the wildfire season of 2003, the costs of fighting wildfires in the Western portion of the U.S. have been estimated to be in the hundreds of millions of dollars. 
     But the costs associated with fighting wildfires pale in comparison to the costs of lost homes and other structures destroyed by wildfires. For example, according to the Insurance Services Office, Inc. (www.iso.com), the estimated insured losses arising out of the wildfires in San Diego and San Bernardino counties in Southern California in 2003 alone exceed over $2 billion. Of this, over $1 billion in payments arise out of a single wildfire—the Cedar Fire—which destroyed over 2,200 residential and commercial buildings. On a nationwide basis, the annual insured losses attributable to wildfires are undoubtedly much higher. 
     Given the staggering amounts of economic and environmental damage caused by wildfires, there is increasing interest in mitigation techniques that reduce the risks to both communities and forest lands. With respect to homes and communities, there are numerous wildfire mitigation strategies that can be taken to alleviate the risk of wildfires destroying residences. These include relatively simple measures such as establishing an effective “defensible space” around homes located in at-risk areas. Another simple approach that many communities have adopted on a community-wide basis is decreasing the fuel loads around urban-wildland interfaces. Good community planning before residential areas are built is also important, since it may be unwise to locate residential developments in areas that are highly prone to wildfires. 
     Nonetheless, homes, commercial structures and other buildings continue to be built at the edges of the urban areas where the risk of wildfire is the greatest, and even deep in forested areas. There are several known systems specifically designed to deliver fire retardant to and around structures when a wildfire threatens. As an example, Firebreak Spray Systems, LLC, the assignee of the present invention, manufactures and installs a variety of retardant application systems that are designed to be installed in and around homes. Another example of a large retardant application system is exemplified by U.S. Pat. No. 5,165,482, which describes a preemptive fire deterrent system that, among other things, applies water to specific areas on and around a structure when a wildfire approaches. Large systems such as those installed by Firebreak Spray Systems, LLC and that typified by the &#39;482 patent are known to be effective, but for a variety of reasons, may not be appropriate for all homeowners and all situations. Specifically, there is a need for improved apparatus for applying fire retardant to specific locations, without all of the equipment and infrastructure needed in large systems. 
     The present invention defines a portable, self contained apparatus for applying fire retardant to specific locations, typically a structure or a perimeter around a structure in order to prevent flames from igniting the structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood and its numerous objects and advantages will be apparent by reference to the following detailed description of the invention when taken in conjunction with the following drawings. 
         FIG. 1  is a first illustrated embodiment of a portable fire retardant application apparatus according to the present invention, showing the apparatus in perspective view. 
         FIG. 2  is an exploded perspective view of the apparatus illustrated in  FIG. 1 , showing certain components of the apparatus. 
         FIG. 3  is a bottom plan view of the apparatus shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first illustrated embodiment of a portable fire retardant application apparatus  10  according to the present invention is shown in  FIGS. 1 through 3 . At times in this detailed description of the invention structural features are described with reference to directional terms such as “upper”, “lower”, etc. Such relative directional terms correspond to the general naming convention based on the apparatus  10  as it rests on a ground plane with the wheels resting on the ground and with the handle end of the apparatus being the “forward” end. Continuing with examples based on this naming convention, the “rear” end of the apparatus is the end opposite the forward end, and so on, and the “interior” of the container refers to the interior of the fire retardant container, described below. 
     It should also be noted at the outset that the apparatus shown in the drawings and described herein is of a specific size. However, the invention is not limited to any specific size unless the invention defined in the claims is so-limited. 
     With reference now to  FIG. 1 , apparatus  10  comprises a main body that defines a container body or tank  12  for holding a liquid fire retardant agent. There are several liquid fire retardant&#39;s that are commercially available and which function well with the application apparatus  10  described herein. The fire retardant used in apparatus  10  is a liquid that flows readily through the plumbing systems and through the nozzles used with the apparatus. Because the retardant may not be used for several years after tank  12  is filled, the retardant is preferably not prone to degradation in effectiveness over time and stratification is preferably minimal. And because the fire retardant may be sprayed onto buildings, the retardant preferably does not discolor building surfaces, does not harm vegetation, and causes no environmental damage. Liquid fire retardant compositions available from Astaris (www.astaris.com) and sold under the brand name PHOS CHEK™ are one example of suitable fire retardants. Another suitable retardant is available under the brand name FIRE-TROL™ from various sources including www.firetrolcanada.com. Preferably the fire retardant that is used in system contains no colorants and/or is decolorized. 
     Tank  12  is preferably fabricated from a plastic material such as high density polyethylene that is lightweight, strong and chemically resistant to the fire retardant that is contained in the tank so that neither the tank nor the retardant degrades over time and storage. The tank  12  shown in the figures is formed in a single piece by injection molding. Tank  12  includes a handle  14  molded into the body at the forward end  16 . A pair of wheels  18 , only one of which is shown in  FIG. 1 , is attached to opposite ends of an axle  20  and the wheel/axle combination is attached to the lower side  22  of tank  12  at the rearward end  24  of the tank. It will be appreciated that the tank may equivalently be made portable by mounting the wheels to a separate chassis and mounting the tank to the chassis. 
     The tank  12  shown in  FIG. 1  includes capacity graduation indicators  26  on side wall  28  of the tank. Preferably, the side wall of tank  28  is either translucent so that a user may readily see the fill-level of fire retardant contained in the tank, or a translucent fill window is provided so the user may inspect the volumetric amount of retardant in the tank  12 . The tank  12  shown in the figures has a capacity of 15 gallons, but it will be appreciated that the volume of the tank may vary considerably and that the invention is not limited to any particular tank volume or size. A generally flattened label space  30  is formed as an integral part of tank  12  on side  28 . Various indicia may be included on the label space, including blank space on which the user may write information such as the kind of fire retardant that is held in tank  12 , and the date on which the retardant was added to the tank. 
     A cap  32  is threaded onto a fill opening on the upper surface  34  of tank  12 . As detailed below, when cap  32  is removed the fill opening may be accessed to add retardant to the tank. Apparatus  10  includes a battery well or compartment  36  that contains a battery (described below) and a switch  38  which controls power to a pump, which also is described below. Battery compartment  36  defines a compartment that is sealed off from the interior of tank  12  and yet which defines a battery compartment that lies within the profile of the tank. A battery cover plate  40  that is removably attached to the tank with screws  42  that thread into threaded openings at cooperative positions in each of the four corners of the battery compartment to seal the battery into the compartment. A wiring harness  44  extends through cover plate  40  and provides an electrical connection to an external power source so that the battery may be charged. 
     Turning now to  FIG. 2 , the components described above may be seen in an exploded view. Wheels  18  are attached to the opposite ends of axle  20  in any convenient manner and the axle is attached to the lower side  22  of tank  12  with keeper plates  46 , which are attached to the tank with screws  48 . Cap  32  is preferably internally threaded and threads onto an upwardly extending, threaded lip  50 . When cap  32  is removed as shown in  FIG. 2 , an access opening  52  is defined into tank  12 —fire retardant is added to tank  12  through access opening  52 . As noted, battery compartment  36  defines a compartment that is sealed off from fire retardant that is contained in tank  12 , yet as shown in  FIG. 2 , the compartment  36  is housed within the interior tank itself. The compartment  36  is preferably molded into the tank body or as an integral component thereof, or may be a separate component that is attached to the tank. In either case, the compartment  36  houses battery  54 , which is a 12 volt battery that is electrically attached to and powers pump  56 , which is attached to a recess formed in the lower surface  22  of tank  12 . 
     The wiring harness that provides the electrical connection from the battery  54  to the terminals on pump  56  is shown generally with reference number  58 . Preferably, the wiring connections extend through the interior of tank  12  directly from the battery to the pump. However, it will be appreciated that the electrical interconnections may be routed from the battery to the pump in any convenient manner. With battery  54  inserted into compartment  36  and the electrical interconnections made between the battery and the pump  56 , the electrical connection between switch  38  and battery  54  is made and the cover plate  40  is screwed into place. In  FIG. 2  the wiring harness  44  is illustrated removed from the battery  54  and a switch  38  is shown wired into the wiring that attaches to the positive terminal  55  of battery  54 . Thus, end  39  of harness  44  attaches to positive terminal  55  and end  41  of the harness attaches to negative terminal  57 . 
     Pump  56  is a conventional pump that is has an electric motor  58  that is operable by 12 volt battery  54  and a pump unit  60  that has an inlet  62  that is fluidly connected to the interior of tank  12  and an outlet  64  that has a fitting  66  that may be connected to hosing and a nozzle assembly through which fire retardant is sprayed. More specifically, as shown in  FIG. 3 , pump  56  is bolted to a recess  67  that is formed in the lower surface  68  of tank  12  with four bolts  70 . Pump inlet  62  is plumbed directly to tank  12  through tubing  72 , which extends into the tank interior. Pump outlet  64  terminates at a fitting  66  which is housed in a recess  74  in the tank  12 —the fitting is a coupler that is accessible from the side of the tank and is a standard detachable hose coupling. The combined pump inlet  62 , pump  60  and pump outlet  64  defines a fluid flow path for fire retardant flowing from the interior of tank  12  to a hose and distribution nozzle assembly  80 , which are shown schematically in  FIG. 3  and which includes a hose  82  that has a hose coupler  84  on one end that is removably attachable to fitting  66 , and a distribution nozzle such as spray nozzle  86  on the opposite end. Spray nozzle  86  preferably includes a manually operable trigger  88 . 
     Some kinds of fire retardants that may be used in apparatus  10  may tend to stratify over time. Depending upon the type of fire retardant used, tank  12  may include an internal agitator such as a paddle-type mixer, powered by motor  58  and shown schematically in  FIG. 2  with reference number  90  to keep the fire retardant homogenous over time. Alternately, the user may mix any fire retardant that has stratified by simply shaking the apparatus  10 . 
     Operation of apparatus  10  will now be detailed. When apparatus  10  is not in use, or “idle”, the tank  12  may be stored either filled with liquid fire retardant or empty. Hose and nozzle assembly  80  may be either attached or detached. Preferably, battery  54  is connected to an external power source such as a standard 110 volt powered wall outlet with charger cord  45 , which attaches to wiring harness  45  to charge the battery and maintain the battery in an optimally charged condition. When a homeowner or other user determines that a structure or other area is imminently threatened by wildfire or other fire threat, the owner detaches the charger cord  45  and makes sure that the hose and nozzle assembly  80  is connected. If the tank  12  is empty, the tank is filled with retardant. The entire apparatus  10  with tank  12  full is then wheeled to the location where retardant is to be applied and the switch  38  is moved to the “on” position. This begins operation of motor  58  and pump  56 , and also mixing paddle  90  if the apparatus includes such a mixing device. Fire retardant is then sprayed through spray nozzle  86  onto whatever surfaces or structures the owner deems most appropriate. The fire retardant used in the apparatus  10  is preferably of the type that will remain on the surfaces onto which it has been sprayed, providing continuing protection against wildfire, until the retardant residual has been washed off. 
     As an alternative or option, pump  56  may be adapted for being powered by a secondary power supply such as 110 volt grid power supply. However, this requires an extension cord running from the power supply (i.e., either a powered wall outlet or a generator), and the range of the apparatus  10  is therefore limited. 
     The apparatus  10  according to the present invention defines a self-contained, fully powered and rechargeable retardant delivery system that may be stored until needed, then quickly wheeled to the location where retardant is to be applied. Even if grid power is interrupted by a wildfire, the apparatus  10  is fully powered and operable without an external power source. 
     While the present invention has been described in terms of a preferred embodiment, it will be appreciated by one of ordinary skill that the spirit and scope of the invention is not limited to those embodiments, but extends to the various modifications and equivalents as defined in the appended claims.