Abstract:
Improvements to a portable fire extinguisher are disclosed. The improvements allow for frequent and simpler untrained and automatic self servicing of a fire extinguisher. The improvements include an anti-bridging mechanism that can be articulated from the exterior of the chamber to fluff, mix or stir the powder within the chamber to keep it in a liquefied state. Additional improvements include a larger opening to more quickly fill and inspect the powder within the chamber. Another improvement includes the use of a CO 2  canister located external to the chamber to allow easier servicing or replacement of just the CO 2  canister as well as the ability to maintain the chamber in an un-pressurized condition, allows for non-HASMAT shipping. These features will extend the service intervals while maintaining the fire extinguisher in a ready condition.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to improvements in portable fire extinguishers. More particularly, the present invention relates to a fire extinguisher that allows for external mixing, fluffing, actuating or stirring of the powder within the chamber to provide anti-bridging of the powder to keep it in a liquefied state, a larger opening in the chamber to allow easier filling of the chamber and a CO 2  canister that is located external to the extinguisher chamber. 
         [0002]    Most portable fire extinguishers are of a similar design where the fire extinguishing powder is contained in a pressurized chamber. Fire extinguishers of this type require scheduled maintenance because the powder within the chamber can settle and cake preventing it from being dispensed when needed. The pressure within the chamber may also leak over time and be insufficient to propel the powder out of the dispensing nozzle. A further limitation, based upon this design is due to the pressurized condition of the chamber, powder is placed into the chamber in a small opening in the top of the extinguisher. This scheduled maintenance allow moisture intrusion causing caking. Current extinguishers can only be service by trained certified technicians, and the certification is issued by the fire marshal for each state. 
         [0003]    Current extinguishers are open to wear and tear because of the constant pressure and tear down process. When serviced they are fires into a recycling chamber and all the parts must be disassembled and cleaned. All the pressure rings must be replaced and every part must them be re-assembled with new powder being placed within the chamber prior to pressurizing the chamber. The servicing of current fire extinguishers often creates more wear and tear on the fire extinguisher than when it is used to extinguish a fire. 
         [0004]    U.S. Pat. No. 6,189,624 issued to James on Feb. 20, 2001 and Japan Patent Number JP9,225,056 issued to Yamazaki Tomoki on Sep. 2, 1997 disclose fire extinguishing mechanisms where the chamber is not continuously pressurized, and the pressurized chamber is a separate entity integrated within the chamber. While these patents disclose a separate pressurized canister, the canister is not located in a position that is easy to service, replace, or inspect. This minimizes the ability determine the charge level of the CO, cartridge. 
         [0005]    U.S. Pat. No. 2,541,554 issued to C H Smith on Feb. 13, 1951 and Russian Patent Number RU2,209,101 issued to Glavatski G. D. Et Al. Nov. 2, 2002 disclose a fire extinguisher with external CO 2  gas cartridge. In the case U.S. Pat. No. &#39;554 the CO 2  gas cartridge sits on top of the fire extinguisher chamber and is not integrated within the handle of the fire extinguisher. In the case of RU &#39;101 CO 2  gas cartridge is external to the extinguisher and is connected to the extinguisher with a pipe or hose. While both of these patents disclose a CO 2  cartridge that is external to the chamber, neither of them is placed in the handle to allow a configuration of the fire extinguisher that is simple to inspect and replace. 
         [0006]    Russian Patent Number RU2,209,101 issued to Glavatski G. D. Et Al. Nov. 2, 2002 discloses a fire extinguisher with an internal fluffing mechanism consisting of a coiled spring. It is known that one of the problems with powder type fire extinguishers is the possibility that the extinguishing powder within the chamber can cake and harden if it is not fluffed to keep the powder in liquid configuration. While the RU &#39;101 patent discloses a fluffing mechanism, the fluffing mechanism is operated by a wound spring, and one the spring has been used there is no mechanism to wind the spring. The proposed product does not have this limitation because it provides an external mechanical interface that allows a user to manually fluff the powered. 
         [0007]    Due to the pressurized condition that exists with pressurized fire extinguishers, the opening where powder is placed into the extinguisher is limited due to the structural requirement to maintain pressure within the chamber at all times. The proposed application eliminates this need by providing an external CO 2  gas cartridge, thus allowing the chamber to exist in a normally un-pressurized condition. Because the chamber is not under pressure the top opening of the extinguisher can be enlarged to allow easier filling of the fire extinguisher with powder, or checking the amount and or condition of the powder within the chamber. 
         [0008]    What is needed is a fire extinguisher with an external gas cartridge where the gas cartridge is located in the handle, a fluffer is accessible from outside the chamber, and the chamber has an enlarged top opening for filling the extinguisher. The proposed fire extinguisher provides this solution by providing a fire extinguisher with an external gas cartridge, external fluffer and large opening. 
         [0009]    It is an object of the fire extinguisher to eliminate the need for service personnel to enter secure areas. The extinguisher can have a higher level of service. Can be operated automatically “self service” and or manually services by the owner or end user. This eliminates the need for non-employees to enter the privacy of business and government areas. This extinguisher can be operated, maintained, refilled and charged with no special training or equipment allowing for anyone who purchases it to have it function like any of the office equipment that is available to day like a copier, printer or water cooler. The proposed fire extinguisher is not required to be broken down when it has been fired. 
         [0010]    The reduced outside servicing and maintenance of the fire extinguisher is ideal for placement of the fire extinguisher to be placement in secure areas. This will reduce or eliminate the possibility that a terrorist could utilize the fire extinguisher as a weapon, or use false identity as an extinguisher service person to gain access to a secure area. 
         [0011]    It is an object of the fire extinguisher to provide a fire extinguisher with an external gas canister. The external canister allows the chamber to exist at or near ambient pressure that reduces the need to utilize a high strength chamber. The standard CO 2  cartridge that is used in other applications can be easily adapted to operate with the fire extinguisher. Since the CO 2  cartridge is external to the chamber it can be easily replaced or swapped without replacing the entire fire extinguisher. This provides a tremendous benefit when a large number of fire extinguishers need to be service at one time. 
         [0012]    it is another object of the fire extinguisher to provide a fire extinguisher with an externally accessible fluffing mechanism. The externally accessible fluffing mechanism promotes anti-bridging of the powder within the chamber to keep it fluffed, agitated, stirred or disturbed to prevent caking of the powder and keep the powder in a liquefied state so it is easier to spray the powder onto a fire. The fluffing is accomplished with paddles, flapper, chains rods or other mixing mechanisms located within the chamber. The mixing mechanism is accessed by a connection on the top, bottom or side of the chamber and can be either manually operated or operated with a key of some type. 
         [0013]    It is still another object of the fire extinguisher to provide a fire extinguisher with an enlarged filling opening. The enlarged filling opening makes it easier and faster to fill and or empty the chamber. The top can also be easily removed to visually inspect the condition of the powder within the chamber. 
         [0014]    Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  shows an isometric view of a preferred embodiment of the improved fire extinguisher. 
           [0016]      FIG. 2  shows a side sectional view of the preferred embodiment of the fire extinguisher shown in  FIG. 1 . 
           [0017]      FIG. 3  shows a bottom view of the preferred embodiment of the fire extinguisher shown in  FIG. 1 . 
           [0018]      FIG. 4  shows a mid cylinder sectional view of the preferred embodiment shown in  FIG. 1 . 
           [0019]      FIG. 5  shows a top view of the preferred embodiment of the fire extinguisher shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]      FIG. 1  shows an isometric view of a preferred embodiment of the improved fire extinguisher  10 . The chamber  20  is substantially a cylindrical shape with a bottom and a top. In the preferred embodiment the chamber is made from a lightweight resilient material such as plastic, but the chamber could also be made of steel, brass, copper or aluminum. On the top of the chamber the fire extinguishing dispensing apparatus is provided. The top is screwed onto the chamber, but it could also be attached with a bayonet or latching mechanism. The lid fits on top of an enlarged opening  70  on the chamber to allow easier filling of the chamber  20  with fire retardant materials. A wall hanging mechanism can be incorporated into the top of the extinguisher, wrap around the body of the cylinder or fork the top of the extinguisher. A handle  40  allows the operator to hold the extinguisher in an upright orientation when it is being used. The fire extinguisher can also be stored and or transported in the upright orientation, but the upright orientation is not critical for the storage or operation of the extinguisher. Within the handle  40  a pressurized gas canister  50  is located. While in the preferred embodiment the pressurized-gas canister is shown within the handle other locations such as within the top of the extinguisher or adjacent to the hose are contemplated. 
         [0021]    The canister  50  consists essentially of a compressed gas cartridge, but canisters of different types of gas are possible that do not promote spreading of the fire. Because the gas within the canister is under high pressure or in a liquid state, a small canister of gas is required to expel the contents of the chamber  20 . It is also contemplated that multiple gas canisters can be placed within the handle to accommodate a larger fire extinguisher without deviating from the inventive nature of the design. Gas canisters are available from a variety of sources and can be replaced or serviced without the need to service the entire fire extinguisher. The handle  40  provides some protection to the canister in the event the fire extinguisher is dropped or roughly handled. A trigger mechanism  60  opens the gas canister to pressurize the chamber and expel the fire extinguishing media into and out of the exit port or application nozzle  90 . A control valve  91  opens and closes the exit port to prevent fire extinguishing powder from pouring out of the extinguisher when the trigger  60  is no longer being depressed. The path from the gas canister  50  to the application nozzle  90  is best shown and described in  FIG. 2 . 
         [0022]      FIG. 2  shows a side sectional view of the preferred embodiment of the fire extinguisher  10  shown in  FIG. 1 . This figure shows the chamber  20  filled with the fire extinguishing media  25 . In the preferred embodiment the chamber is made from a lightweight resilient material such as plastic, but the chamber could also be made of steel, brass, copper or aluminum. Various types of fire extinguishing media can be placed within the chamber. The upper portion of the chamber includes an enlarged opening  70  where it joins with the top  30  of the extinguisher. The enlarged opening  70  is greater than 50% of the diameter of the cylindrical fire extinguisher, but could be up to and including the same diameter as the cylinder with a threading mechanism located on the exterior lip of the cylinder. It is also contemplated that the cylinder be fabricated from tubular stock where both the top and the bottom of the extinguisher is identical and the ends are attached to the tube when the fire extinguisher is assembled. In the preferred embodiment the opening is between 75% and 90% of the diameter of the fire extinguisher. The larger opening allows the contents of the fire extinguisher to be filled, emptied, inspected, and serviced more easily. The top is screwed onto the chamber, but it could also be attached with a bayonet or latching mechanism. The top  30  of the fire extinguisher provides the propellant and the connections to emit the fire extinguishing material  25 . 
         [0023]    A gas filled canister  50  is located within the handle  40  of the extinguisher. It can be seen from this figure that the gas canister exists substantially within the handle. The handle provides some protection to the canister for accidental damage. A small portion of the gas canister extends beyond the end of the handle to allow access to the gas canister so it can be installed, removed or serviced without the need to disassemble other parts of the fire extinguisher. The gas canister is threaded into a fitting  52  within the handle of the extinguisher. The fitting can be of a variety of types that allows engagement of the canister to the extinguisher allowing the gas to be exhausted from the canister into the body of the fire extinguisher. A trigger  60  or other activation mechanism controls a valve  62  to regulate the flow of the gas from the canister through tube  54  and into the fire extinguisher at  56 . Various safety pins, locks, tabs or other devices can be incorporated to reduce or prevent the possibility of accidental activation of the trigger. 
         [0024]    In the figure the chamber is shown only partially filled to provide a view of the fluffing mechanism(s)  120 . The fluffing mechanism conditions the fire retardant media to provide anti-bridging of the media within the chamber to agitate, fluff, turn, disturb, stir, ruffle, and or alters the condition of the media to allow the media to maintain a powder consistency. This allows the fire retardant powder media to remain in a liquefied state so it is easier to spray the powder onto a fire. The conditioning of the media can be performed using a variety of methods and in the preferred embodiment the conditioning is performed with an appendage  110  that can be articulated from the exterior  100  of the chamber. The appendage is a shaft that extends the length of the chamber and has a number of flaps  120  attached to the appendage. While flaps are shown and used in the preferred embodiment a variety of other appendages are contemplated that can condition the media that include but are not limited to rods, paddles, arms, disks, cable, chains or combination thereof. It is also contemplated that the appendage can be a simple hook or chain that conditions the fire extinguishing media. As previously described the appendage terminates  100  at the bottom of the chamber where it can be articulated, but the appendage could terminate at the top or sides of the chamber. The termination at the bottom of the chamber can allow articulation that requires either a key to attach to the appendage, or may terminate with manual knob, handle, wheel or other extension. 
         [0025]    A hole  82  extends from bottom of the fluffing tube within the chamber to a passage  80  that transports the fire extinguishing media from within the chamber to the application nozzle  90  where it exits through a hole in the end of the nozzle. In operation when the trigger  60  is depressed the valve  62  is opened and gas from the canister  50  is expelled from the tube  54  into the chamber  20 . A powder expeller valve  91  is closed to prevent power from spilling out the end of the hose when not in use, and opened to allow the powder to dispense on a fire when needed. The chamber becomes pressurized and fire suppressant media  25  is pushed through tube  82  where it is dispensed out the port  80  and through the nozzle  90 . In another contemplated embodiment the nozzle is flexible to allow a user to hold the fire extinguisher and direct the fire extinguishing media out of the hose to a fire. While an open port  90  is shown in the preferred embodiment other dispensing orifices can be used such as valves, tubing, spray nozzles or similar are contemplated. It is contemplated that an over pressure relief valve can be incorporated within the fire extinguisher to vent any excessive pressure from within the cylinder that could-cause the fire extinguisher to burst due to over pressurization of the chamber. Another contemplated feature can be a pressure gauge that will provide information on the amount of pressure in the gas canister to ensure that it is sufficiently charged for use when needed. After using the fire extinguisher, it can be opened, refilled and the gas canister replaced to allow the fire extinguisher to be returned to service like other types of office equipment like copiers or printers. 
         [0026]      FIG. 3  shows a bottom view of the preferred embodiment of the fire extinguisher  10  shown in  FIG. 1 . This view is one contemplated embodiment with access to the articulating appendage with a hex  100  or similar key drive attachment and a handle/knob  105  that can be manually turned to fluff the fire retardant media within the chamber  20 . A battery powered drill or screwdriver can be attached to the hex drive socket and the powder within the fire extinguisher can be quickly fluffed. It is further contemplated that the fluffer could be operated by an automatic or manual motor that operates on a timer to fluff the powder at intervals. In this view the gas canister  50  is shown within the handle  40 . 
         [0027]      FIG. 4  shows a mid cylinder sectional view of the preferred embodiment shown in  FIG. 1 . This sectional view is cut through the chamber  20  to show the flapper(s)  120  on the appendage  110 . The inlet tube  56  from the gas canister is shown in one contemplated location. The gas canister  50  is shown within the handle  40  with the activation trigger  60 . The enlarged opening of the chamber  70  can be seen where it narrows from the body of the chamber  20 . The exhaust passage  80  is shown that transports fire retardant media from the fire extinguisher passage and out the application nozzle  90 . 
         [0028]      FIG. 5  shows a top view of the preferred embodiment of the fire extinguisher  10  shown in  FIG. 1 . This view is one contemplated view as the fire extinguisher would appear when viewed from the top of the extinguisher. The gas canister is not visible but a portion of the handle  40  can be seen as it extends out the sides under the trigger mechanism cover  60 . The handle  40  further provides some protection to the gas canister to reduce the possibility of damaging the gas canister. The chamber exists under the top  30  of the fire extinguisher and the nozzle  90  is shown on the side opposite the handle. 
         [0029]    Thus, specific embodiments of an improved fire extinguisher have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims.