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1. Field of the Invention
This invention relates to improvements in portable fire extinguishers. More particularly, the present invention relates to a fire extinguisher that uses a replaceable gas cartridge that provides a propellant to push fire extinguishing media outside of the fire extinguisher.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Most portable fire extinguishers are of a similar design where the fire extinguishing powder is contained in a continuously pressurized chamber. Fire extinguishers of this type require scheduled maintenance by trained and certified technicians with certification issued by the fire marshal for each state. This maintenance involves discharging, cleaning, and refilling the extinguisher. If not done periodically, the powder within the chamber becomes compacted and/or the pressure within the chamber may leak and be insufficient to propel the powder out of the dispensing nozzle. If maintenance is not done correctly, moisture absorption by the extinguishing powder will cause caking and block the dispensing nozzle. The aforementioned conditions would prevent the proper dispensing of extinguishing powder when needed.
Current extinguishers are open to wear and tear because of the constant pressure and tear down process. When serviced they are discharged into a recycling chamber and all the parts must be disassembled and cleaned. All the pressure rings must be replaced and every part must then 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.
U.S. Pat. No. 6,189,624 issued to James on Feb. 20, 2001 and Japan Patent Number JP 9,225,056 issued to Yamazaki Tomoki on Sep. 2, 1997 discloses fire extinguishing mechanisms where the chamber is not continuously pressurized, and the pressurized cartridge is a separate entity integrated within the chamber. While these patents disclose a separate pressurized cartridge, the cartridge is not located in a position that is easy to service, replace, or inspect. This minimizes the ability determine the charge level of the pressurized cartridge.
U.S. Pat. No. 2,541,554 (“U.S. '551”) issued to C H Smith on Feb. 13, 1951 and Russian Patent Number RU 2,209,101 (“RU '101”) issued to Glavatski G. D. Et Al. Nov. 2, 2002 discloses a fire extinguisher with an external CO2 gas cartridge. In the case of U.S. '554 the CO2 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 '101 the CO2 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 CO2 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.
U.S. Pat. No. 7,128,163 issued on Nov. 21, 2006, U.S. Pat. No. 7,318,484 issued on Jan. 15, 2008 and U.S. Pat. No. 7,793,737 issued Sep. 14, 2010, all to Hector Rousseau disclose a fire extinguisher with a gas cartridge in the handle and a fluffing mechanism. While these patents have similar features, the gas cartridge is oriented to discharge vertically upwards. When gas is discharged from a cartridge containing compressed liquefied gas, such as CO2, evaporation must occur from the contained liquid in order to maintain thermodynamic equilibrium with the cartridge. Heat is required to drive the evaporation, and if the available heat from the surrounding cartridge environment is insufficient, the compressed liquefied gas temperature and pressure will drop. For CO2, if the pressure drops below 75 psig, liquid CO2 will solidify into dry ice. Since cartridge-style fire extinguishers are usually used immediately after puncturing the cartridge, any dry ice formed will not have time to absorb enough heat to phase change into gas and contribute to the effective discharge of the fire extinguisher. This effect is magnified at low environmental temperatures, where existing commercial cartridge-style fire extinguishers have been measured to waste 40% by mass of the CO2 charge when conditioned at −40° C. However, even though this gas is unused during typical discharge, the extinguisher must be structurally designed based on the full pressurizing gas load, leading to less than optimal designs. In addition, based on the unique properties of CO2, torturous paths between the fire extinguisher main chamber and the cartridge must be avoided to minimize the risk of blocking the flow path with dry ice or freezing valves due to resulting low temperatures from CO2 expansion.
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 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.
What is needed is a fire extinguisher with a replaceable gas cartridge where the gas cartridge is oriented to discharge only liquid propellant into the body of the extinguisher and the fire extinguisher further has a fluffer that 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 oriented to discharge downward, external mechanism to actuate an internal fluffer, and a large opening. By discharging the compressed liquefied gas downward, liquid is discharged into the fire extinguisher, and as such, the cartridge does not need to absorb nearly as much heat to drive the necessary evaporation to maintain temperature and pressure within the cartridge above the triple point, and thus, solidification of the propellant is avoided. For compressed liquefied CO2, this concept has been experimentally demonstrated to discharge nearly 100% of the CO2 from the cartridge, even with the fire extinguisher preconditioned to −40° C.
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 by automatic “self-service” and or manually serviced 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 minimal training and without need for custom equipment.
The reduced outside servicing and maintenance of the fire extinguisher is ideal for placement of the fire extinguisher 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.
It is an object of the fire extinguisher to provide a fire extinguisher with an external gas cartridge. The inverted external gas cartridge allows the liquid within the gas cartridge to vent directly into the fire extinguisher. Well accepted gas cartridges, such as CO2 or nitrogen cartridges, that are used in other applications can be adapted to operate with the fire extinguisher. Since the gas 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 serviced at one time.
It is an object of the fire extinguisher to provide a fire extinguisher to eliminate chemical reaction of the fire extinguishing media with the extinguisher housing. Polycarbonate is a cost effective candidate for a transparent cylinder, however when polycarbonate is in intimate contact with ammonia gas, material degradation will occur at a rate related to the gas concentration and exposure duration. Since ammonia gas may be emitted from mono-ammonium phosphate (the main constituent of ABC dry chemical) at elevated temperatures, there is a need to isolate or protect polycarbonate from direct exposure.
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 to ensure proper discharge 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 tool of some type.
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.
It is still another object of the fire extinguisher to provide a quick opening and closing top housing thereby allowing a user to quickly open and refill the fire extinguisher. This also allows a fire fighter the load the desired fire extinguishing media based upon the type of fire.
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.
With reference to FIG. Nos. 1 & 2, a handle 40 allows the operator to hold the fire extinguisher 19 by placing a hand through the grip area 41. This allows the fire extinguisher 19 to be held in an upright orientation when it is being transported or used. The fire extinguisher 19 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 fire extinguisher 19. Partially within the handle 40 and top housing 30 a replaceable pressurized gas cartridge 50 is located under a transparent portion 42 of handle 40. The transparent portion 42 provides the ability to verify that the pressurized gas cartridge 50 is installed within the fire extinguisher 19. While in the preferred embodiment the pressurized gas cartridge 50 is shown partially within the handle 40 and top housing 30 other locations are contemplated.
The replaceable pressurized gas cartridge 50 consists essentially of a compressed gas cartridge of CO2, but cartridges of different types of gas are possible that do not promote spreading of a fire. Because the gas within the cartridge is under high pressure and possibly in a liquid state, a small cartridge of propellant is required to expel the internal fire suppressant material 99 of the fire extinguisher 19. It is also contemplated that multiple gas cartridges can be used to accommodate a larger fire extinguisher without deviating from the inventive nature of the design. Pressurized gas cartridges are available and can be replaced or serviced without the need to service the entire fire extinguisher 19. The handle 40 and its transparent portion 42 provides protection to the pressurized gas cartridge 50 in the event the fire extinguisher 19 is dropped or roughly handled. A trigger mechanism 60 activates the pressurized gas cartridge 50 to pressurize the chamber 22 and expel the fire suppressant material 99 into and out of the hose 81 and exit port 90. A control valve lever 92 opens and closes the exit port 90 to prevent fire suppressant material 99 from pouring out of the extinguisher when the chamber is pressurized. The puncturing mechanism of the pressurized gas cartridge and the path from the gas cartridge 50 into the chamber 22 is shown and described in
Polycarbonate is a cost effective candidate for providing a transparent bottom housing 20, however when polycarbonate is in contact with ammonia gas that is the main constituent of ABC dry chemical, material degradation will occur, especially at elevated temperatures, there is a need to isolate or protect the polycarbonate from direct exposure. When using polycarbonate material, the interior of the bottom housing 20 is preferably coated with a transparent protection coating 21 with a Siloxane base, or equivalent. This coating 21 improves chemical and abrasion resistance as well as provides UV protection. The coating 21 can be applied in any number of methods to isolate the polycarbonate exposure to Monoammonium phosphate and any emitted ammonia gas. The coating 21 would provide necessary chemical resistance whereas the polycarbonate bottom housing 20 would provide necessary strength and impact resistance.
In another contemplated embodiment, construct the bottom housing 20 as a transparent cylinder from two separate cylinders where the inner cylinder 21 is inserted into the outer cylinder 23 of bottom housing 20. This could be accomplished by insert molding a transparent inner cylinder of tritan, acrylic, san or an equivalently performing other material into the polycarbonate outer cylinder 23. The outer cylinder 23 of would be polycarbonate, and would serve to provide the assembly with necessary strength and impact resistance, whereas, the inner cylinder 21 would provide the necessary chemical resistance to Monoammonium phosphate. For these embodiments the strength of the inner cylinder 21 could be sufficient to ensure safe operation in the event outer cylinder 23 of bottom housing 20 is damaged from a severe environment or impact.
To expel fire suppressant material 99 from within the fire extinguisher 19 an operator must puncture the pressurized gas cartridge 50. The pressurized gas cartridge 50 is secured by threads 52 or otherwise secured into the top housing of the fire extinguisher 19. Within the top housing 30 a replaceable pressurized gas cartridge 50 is located under a transparent portion 42 of handle 40. The handle 40 and its transparent portion 42 provides protection to the pressurized gas cartridge 50 in the event of the fire extinguisher being dropped, and also allows the operator to verify that the pressurized gas cartridge 50 is installed within the fire extinguisher 19. To puncture the pressurized gas cartridge 50 the operator lowers or rotates the trigger mechanism 60 that pushes the puncture pin 62 into the pressurized gas cartridge 50. Details of the trigger mechanism 60 and the puncture pin 62 is shown and described in more detail in
When liquefied gas is discharged from pressurized gas cartridge 50, evaporation must occur from the contained liquid in order to maintain thermodynamic equilibrium within the pressurized gas cartridge 50. To maintain thermodynamic equilibrium heat is required to drive the evaporation. If the available heat from the surrounding cartridge environment is insufficient the compressed liquefied gas temperature and pressure will drop. For liquefied CO2, if the pressure drops below 75 psig, the liquid CO2 will solidify into dry ice. If dry ice forms, the dry ice will not have time to absorb enough of the surrounding thermal mass to heat the dry ice to change phase into gas and contribute to the effective discharge of the fire extinguisher 19.
The forming of dry ice is exacerbated in low temperatures. Testing agencies such as UL, CSA, and others require operation of a fire extinguisher at temperatures down to −40° C. (−40° F.). If a pressurized gas cartridge with CO2 is oriented with the discharge port vertical in an upright position (i.e., with threads 52 in the upper position), testing has shown that up to 40% of the CO2 (by mass) can remain in the form of dry ice after completion of the fire extinguishers' discharge. When the pressurized gas cartridge 50 contains CO2 and is oriented in an inverted orientation (i.e., with threads 52 in the lower position), the cartridge does not need to absorb nearly as much heat to evaporate the liquid CO2 from the pressurized gas cartridge 50 to maintain temperature and pressure above the triple point, and thus, creation of dry ice within the cartridge 50 is avoided. This concept has been experimentally demonstrated to discharge nearly 100% of the CO2 from the cartridge, even with the fire extinguisher preconditioned to −40° C. (−40° F.). Once the CO2 enters the chamber 22, there is sufficient heat and surface area in the comparatively large volume to rapidly convert liquid CO2 into gaseous CO2.
The mixture of fire suppressant material 99 and gas are pushed through the central shaft 110 and then through the flow path 80 in the top housing 30 where they are pushed through hose 81 to a manually operable valve 95 and are expelled out of the exit port 90. The central shaft 110 has an integral tube 112 where fire suppressant material 99 is pushed into multiple holes in the bottom of the central shaft 110 through integral tube 112. The dispensing nozzle 96 has a valve 95 that is operated with a control rod 94 to open and close the valve 95. The control rod 94 holds the valve 95 closed with a spring 93. An operator depresses the control valve lever 92 to overcome the spring 93 and opens the valve 95. The dispensing nozzle 96 can be operated by either hand. This is shown and described in more detail in
An operator can hold dispensing nozzle 96 of the fire extinguisher 19 in one hand and operate the lever 92 with the same hand. The operator can then direct the dispensing nozzle 96 at the fire. When the lever 92 is depressed, the lever will press against spring 93 and slide the control rod 94 to open the valve 95. When the valve 95 is opened fire suppressant material 99 will flow out of the exit port 90. When the lever 92 is released the spring 93 will close the valve 95 to prevent further dispensing of fire suppressant material 99. This will retain pressure within the chamber 22 of fire extinguisher 19.
In
In
Because the pressurized gas cartridge 50 is inverted, essentially only liquefied gas exits and expands into gas within the fire extinguisher 19 therefore essentially all of the gas within the cartridge is expelled. Because the liquid/gas is expelled at a rapid rate a pressure wave 113 traveling nearly the speed of sound pushes onto the top of the fluffing arms 120. A gusset 116 supports the fluffing arm 120 and prevents the fluffing arm 120 from being sheared off by the pressure wave. In a short period of time, pressure within the fire extinguisher 19 stabilizes. Once valve 95 is opened, the static pressure within chamber 22 pushes the fire suppressant material 99 toward at least one intake hole 114 in the bottom of the central shaft 110 shown in the other figures herein.
Thus, specific embodiments of a portable 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.
This application is a continuation-in-part of applicant's application Ser. No. 12/851,169 filed Aug. 5, 2010, now U.S. Pat. No. 8,757,282 that issued on Jun. 24, 2014, which is a continuation-in-part to application Ser. No. 11/578,494 filed Oct. 12, 2006, now U.S. Pat. No. 7,793,737 that issued on Sep. 14, 2010, that is a continuation-in-part to application PCT/US06/41157 filed on Oct. 12, 2006 which is a continuation-in-part of application Ser. No. 11/266,815 filed Oct. 4, 2005, now U.S. Pat. No. 7,128,163 that issued on Nov. 31, 2006, and claims priority to application Ser. No. 11/714,611 filed on Mar. 6, 2007, now U.S. Pat. No. 7,650,948 that issued on Jan. 26, 2010 and claims priority to application Ser. No. 11/515,471 filed on Sep. 1, 2006, now U.S. Pat. No. 7,318,484 that issued on Jan. 15, 2008, the entire contents of which is hereby expressly incorporated by reference herein.