AU2020204190B2 - Fire extinguisher with internal mixing and gas cartridge - Google Patents

Abstract

OF THE DISCLOSURE Improvements to a portable fire extinguisher are disclosed. This includes a puncturing mechanism for a portable fire extinguisher, the portable fire extinguisher including a chamber (22) configured to hold a fire suppressant material (99) and a pressurized gas cartridge (50) configured to pressurize the chamber (22) when the portable fire extinguisher is activated by a user, the puncturing mechanism comprising: a lift plate (55); a puncture pin (62) coupled to the lift plate (55), the puncture pin (62) configured to puncture the pressurized gas cartridge (50) to release gas therefrom into the chamber (22) of the portable fire extinguisher; and a trigger mechanism (60) coupled to the lift plate (55), wherein movement of the trigger mechanism (60) from a first position to a second position causes corresponding movement of the lift plate (55) and the puncture pin (62) and causes the puncture pin (62) to rupture the pressurized gas cartridge (50) and release the gas therefrom into the chamber (22). 3 /6 40 92 96 Al 93 90 -- 80 94 81 FIG. 3 30 40 42 Al 50 80 60 830 -52 -62 55 20 FIG. 4

Description

3 /6 40

92 96 Al 93 -- 80

94 81 FIG. 3 30

40

42

Al 50 80 60

830 -52

-62

55

20 FIG. 4

INVENTION TITLE FIRE EXTINGUISHER WITH INTERNAL MIXING AND GAS CARTRIDGE CROSS REFERENCE TO RELATED APPLICATIONS

[Para 1] This application is a divisional application of Australian Patent Application No. 2015280284, which is a national phase application of PCT

application No. PCT/US2015/036895, filed 22 June 2015, which claims the

benefit of priority of US Application No. 14/704,820 filed 5 May 2015 and US

Application No. 14/313,761 filed 24 June 2014. All of the above applications

are incorporated by reference herein, in their entirety, and made a part of this

specification.

TECHNICAL FIELD

[Para 2] 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.

BACKGROUND ART

[Para 3] 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.

[Para 4] 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.

[Para 5] U.S. Patent Number 6,189,624 issued to James on February 20, 2001 and Japan Patent NumberJP 9,225,056 issued to Yamazaki Tomoki on September 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 to determine the charge level of the pressurized cartridge.

[Para 6] U.S. Patent Number 2,541,554 ("US '551") issued to C H Smith on

February 13, 1951 and Russian Patent Number RU 2,209,101 ("RU '101")

issued to Glavatski G. D. Et Al. November 2, 2002 discloses a fire extinguisher

with an external CO2 gas cartridge. In the case of US '554 theC02 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 theC02 gas

cartridge is external to the extinguisher and is connected to the extinguisher

with a pipe or hose. While both of these patents disclose aCO 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.

[Para 7] U.S. Patent Number 7,128,163 issued on November 21, 2006, U.S.

Patent Number 7,318,484 issued on January 15, 2008 and U.S. Patent Number

7,793,737 issued September 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 asC0 2, 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. ForC0 2, if the pressure drops below 75 psig, liquidCO 2 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 theCO 2 charge when conditioned at -40 0C. 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 C0 2 , 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 fromCO 2 expansion.

[Para 8] 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.

[Para 9] 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 liquefiedC0 2, this concept has been experimentally demonstrated to discharge nearly 100% of theCO 2 from the cartridge, even with the fire extinguisher preconditioned to -400 C.

[Para 10] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[Para 11] Any discussion of documents, acts, materials, devices, articles or

the like which has been included in the present specification is not to be taken

as an admission that any or all of these matters form part of the prior art base

or were common general knowledge in the field relevant to the present

disclosure as it existed before the priority date of each claim of this

application.

DISCLOSURE OF THE INVENTION

[Para 12] A puncturing mechanism for a portable fire extinguisher, the

portable fire extinguisher including a chamber configured to hold a fire

suppressant material and a pressurized gas cartridge configured to pressurize

the chamber when the portable fire extinguisher is activated by a user, the

puncturing mechanism comprising: a safety knob; a lift plate; a puncture pin

coupled to the lift plate, the puncture pin configured to puncture the

pressurized gas cartridge to release gas therefrom into the chamber of the

portable fire extinguisher; and a trigger mechanism coupled to the lift plate,

wherein movement of the trigger mechanism from a first position to a second

position causes corresponding movement of the lift plate and the puncture pin

and causes the puncture pin to rupture the pressurized gas cartridge and

release the gas therefrom into the chamber, wherein the safety knob is a

rectangular shape having flange portions, wherein horizontal sides of the

trigger mechanism are secured with the flange portions of the safety knob

when the safety knob is in a horizontal orientation thereby preventing the trigger mechanism from moving from the first position to the second position, the trigger mechanism is allowed to pass by the sides of the safety knob to reach the second position when the safety knob is in a vertical orientation thereby releasing the trigger mechanism.

[Para 13] in some examples, movement of the trigger mechanism includes a downward movement of the trigger mechanism toward the chamber, and includes an upward movement of the lift plate and puncture pin away from the chamber.

[Para 14] in some examples of the puncturing mechanism, the puncture pin is coupled to a threaded retainer that is configured to receive the pressurized gas cartridge.

[Para 15] in some examples of the puncturing mechanism, the lift plate is biased by a return spring away from the pressurized gas cartridge.

[Para 16] A method for activating a portable fire extinguisher, the portable fire extinguisher including a chamber configured to hold a fire suppressant material and a pressurized gas cartridge configured to pressurize the chamber when the portable fire extinguisher is activated by a user, the method comprising: moving a safety knob having flange portions from a first safety knob position where the flange portions lock a trigger mechanism to a second safety knob position causing the flanged portions to allow the trigger mechanism to pass by the sides of the safety knob, thereby releasing the trigger mechanism; and moving the trigger mechanism from a first trigger position to a second trigger position; wherein moving the trigger mechanism includes moving a puncture pin that is coupled to the trigger mechanism to rupture the pressurized gas cartridge and thereby release gas from gas cartridge into the chamber.

[Para 17] in some examples of the method, moving the safety knob

includes releasing or ejecting a tamper indicator.

[Para 18] in some examples of the method, moving the first extinguisher

trigger from the first trigger position to the second trigger position includes

moving the trigger mechanism in a first direction, and moving the puncture

pin includes moving the puncture pin in an opposite second direction.

[Para 19] in another example, the method further comprises using a return

spring to bias the puncture pin away from the pressurized gas cartridge.

[Para 20] Further improvements to a portable fire extinguisher are

disclosed. The improvements allow for frequent and simplified inspection and

maintenance of a fire extinguisher with minimal training and without need for

custom equipment. 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 C02

cartridge located external to the chamber to allow easier servicing or

replacement of just the C02 cartridge 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.

[Para 21] in some examples, it is desirable for a fire extinguisher to

eliminate, or reduce, 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.

[Para 22] 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.

[Para 23] in some examples, it is desirable for a fire extinguisher to have 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 CO 2 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.

[Para 24] in some examples, it is desirable for a fire extinguisher to have an

optional externally accessible fluffing mechanism. The size, structure and

necessity of the fluffing mechanism can be based upon the size of the fire

extinguisher. 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.

[Para 25] in some examples, it is desirable for a fire extinguisher to have 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.

[Para 26] in some examples, it is desirable for a fire extinguisher to have 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.

[Para 27] 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 DRAWING(S)

[Para 28] FIG. 1 shows a perspective view of the fire extinguisher.

[Para 29] FIG. 2 shows a cross-sectional view of the fire extinguisher.

[Para 30] FIG. 3 shows a detailed view of the dispensing valve.

[Para 31] FIG. 4 shows a sectional view of the head of the fire extinguisher.

[Para 32] FIG. 5A, 5B and 5C show stages of removing the safety device

prior to discharging the fire extinguisher.

[Para 33] FIG. 6 shows a detailed view of the pressurized gas cartridge

puncturing mechanism.

[Para 34] FIG. 7 shows a detail cross-sectional view of the puncture pin.

[Para 35] FIG. 8 shows a graph of the amount of Dry Ice that is generated

based upon the orientation of the pressurized gas.

[Para 36] FIG. 9 shows the fluffing and siphon tube.

[Para 37] FIG. 10 shows a detail of the multiple siphon intake holes and the

fluffing arm.

BEST MODE FOR CARRYING OUT THE INVENTION

[Para 38] FIG. 1 shows an exterior perspective view of the fire extinguisher 19. The fire extinguisher 19 is substantially a cylindrical shape with a bottom housing 20 and top housing 30. In the preferred embodiment the bottom housing 20 and top housing 30 is made from a lightweight resilient material such as plastic, but could also be made of other materials, including steel, brass, copper or aluminum. The bottom housing 20 may further be fabricated from a transparent material to allow for visual inspection within the fire extinguisher 19. The top housing 30 is screwed onto the bottom housing 20, but it could also be attached with a bayonet or latching mechanism. The bottom housing 20 has an enlarged opening to allow easier filling of the bottom housing 20 with fire suppressant materials. A wall hanging mechanism can be incorporated into the top housing 30 of the fire extinguisher 19, or could wrap around the body of the bottom housing 20, or could fork the top housing 30 of the fire extinguisher 19.

[Para 39] With reference to FIG. 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.

[Para 40] The replaceable pressurized gas cartridge 50 consists essentially

of a compressed gas cartridge of C0 2 , 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.

[Para 41] While some figures in this document show and describe a flexible

hose 81, some contemplated embodiments may include a duct, hollow passage or nozzle 97 where the fire extinguishing media passes from the body of the fire extinguisher out of the nozzle 97 to extinguish a fire. A control valve lever 92 opens and closes the exit port 90 or to prevent fire suppressant material 99 from pouring out of the extinguisher when the chamber is pressurized. When a nozzle 97 is used, a control valve can be located near the nozzle to control the flow of fire extinguishing media out of the fire extinguisher. 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 figure 2.

[Para 42] FIG. 2 shows a cross-sectional view of fire extinguisher 19. An

operator can place their hand or glove through the grip area 41 of the handle

to carry, transport or use the fire extinguisher 19 with either hand. Fire

suppressant material 99 is placed into chamber 22 within the bottom housing

through an enlarged cylindrical opening 70 when the top housing 30 is

disengaged from the bottom housing 20. Over time the fire suppressant

material 99 will become compressed and compacted in the bottom of the

chamber 22. When the fire suppressant material 99 is compacted, risk of

improper discharge increases. Within the fire extinguisher 19 a plurality of

fluffing arms 120 are arranged on a central shaft 110. A fluffing wheel 100

can be accessed from the underside of the fire extinguisher 19. Rotating the

fluffing wheel 100 will re-fluff the fire suppressant material 99 to minimize

risk of improper discharge of suppressant material 99 from the fire extinguisher 19. Turning the fluffing wheel 100 will provide similar loosening of the fire suppressant material 99 as might be found in a food mixer.

[Para 43] 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.

[Para 44] 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.

[Para 45] 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 figures 6

and 7. Once the pressurized gas cartridge 50 is punctured the gas and or

liquid will be forced into the chamber 22.

[Para 46] When liquefied gas is discharged from pressurized gas cartridge

, 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 liquefiedC0 2, if the pressure drops below 75 psig, the liquidCO 2will 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.

[Para 47] 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 withCO2 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 theC02 (by mass) can remain in the form of dry ice after completion of the fire extinguishers' discharge. When the pressurized gas cartridge 50 containsCO2 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 liquidCO 2 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 theC02 from the cartridge, even with the fire extinguisher preconditioned to -40°C (-40°F). Once theC02 enters the chamber 22, there is sufficient heat and surface area in the comparatively large volume to rapidly convert liquidCO 2 into gaseousC0 2

.

[Para 48] 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 siphon tube 112 where fire suppressant material 99 is pushed into

multiple holes in the bottom of the central shaft 110 through integral siphon

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 figure 3.

[Para 49] FIG. 3 shows a detailed view of the dispensing nozzle 96. This

view shows a portion of the handle 40 and the grip area 41. The top housing

includes a flow path 80 from within the fire extinguisher 19, through the

top housing 30. With the valve 95 in the closed position, the fire extinguisher

19 can remain in a pressurized condition after the pressurized gas cartridge

has been punctured. In this "primed" condition all of the pressure and fire

suppressant material 99 within the fire extinguisher 19 is controlled by the

valve 95. The dispensing nozzle 96 has a valve 95 that is connected to a control rod 94. The control rod 94 is pulled back to permit flow from the hose

81 to the exit port 90.

[Para 50] 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.

[Para 51] FIG. 4 shows a sectional view of the top housing 30 of the fire

extinguisher 19. The handle 40 allows the operator to hold the fire

extinguisher 19 by placing a hand through the grip area 41. Trigger

mechanism 60 is connected to a lift plate 55 that lifts the puncture pin 62 into

the sealed end of the pressurized gas cartridge 50 under the transparent

portion 42 of handle 40. The pressurized gas cartridge 50 is secured by

threads 52 or otherwise secured into the top housing 30. Detail of the trigger

mechanism 60 and the puncture pin 62 is shown and described in more detail

in figures 5 and 6. When cartridge 50 is filled with compressed liquidC0 2, the

flow path between the pressurized gas cartridge 50 and the inside of the fire

extinguisher 19 must be as smooth as possible to limit the risk of dry ice forming that can block or restrict the flow path. The bottom housing 20 is shown connected to the top housing 30. When valve 95 is opened, static pressure fromCO2 or compressed gas from the gas cartridge 50 pushes the fire suppressant material 99 down into the openings of central shaft 110 and up through integral siphon tube 112 and then through the flow path 80 to the hose 81. If seals 109 leak with respect to top housing 30, gas from gas cartridge 50 will bypass suppressant material 99 and travel directly into flow path 80 and eventually out valve 95, leading to reduced range and discharge amount of suppressant material 99. To ensure proper assembly of seals 109 to top housing 30, guide features of the top housing 30 capture central shaft 110 during installation of bottom housing 20 to top housing 30.

[Para 52] FIG. 5A, 5B and 5C show stages of repositioning the safety knob 72 prior to discharging the fire extinguisher 19. The initial stage at 5A is how the fire extinguisher 19 will exist prior to activation. In this position the safety knob 72 restricts the trigger mechanism 60 from moving. The safety knob 72 is essentially rectangular thereby locking or blocking the trigger mechanism in one orientation and allowing the sides of the trigger mechanism 60 to pass by the safety knob 72 when the safety knob 72 is rotated 90 degrees. The opposing vertical sides of the trigger mechanism 60 are secured with flange portions 76 of safety knob 72. To allow for activation, safety knob 72 is rotated 68. Safety knob 72 can be operated by either hand.

[Para 53] In figure 5B the safety knob 72 is shown in the vertical orientation to allow the trigger mechanism 60 to pass by the sides of the safety knob 72. When the safety knob 72 is rotated, the rotation causes internal pins 74 to shear and release or eject the tamper indicator 73. The release of the tamper indicator 73 identifies that the fire extinguisher 19 may have been discharged and requires service inspection. Also, when the safety knob 72 is in the vertical orientation, access to the gas cartridge 50 by opening transparent portion 42 of handle 40 has been blocked. The design prevents the insertion of a new pressurized gas cartridge 50 without the trigger mechanism 60 returned to an upright and locked orientation to prevent puncturing the new pressurized gas cartridge 50 upon insertion.

[Para 54] In figure 5C an operator can then pull or push the trigger mechanism 60 downward 69 to where the trigger mechanism 60 is shown in a lower position 67 (as dashed lines). When the trigger mechanism 60 is rotated from the upper to the lower position 67 the puncture pin 62 is pushed into and punctures the pressurized gas cartridge 50. The trigger mechanism 60 can be operated by either hand.

[Para 55] FIG. 6 shows a detailed view of the pressurized gas cartridge 50 puncturing mechanism. The pressurized gas cartridge 50 is secured by threads 52 into a retainer 56 within the top housing 30. The pressurized gas cartridge 50 and the threaded retainer 56 remain stationary as the end of the pressurized gas cartridge 50 is punctured. From this figure, one set of fasteners and duplicate parts has been removed for viewing. The trigger mechanism 60 pivots through an axis 58 to increase the mechanical advantage to puncture the end of the pressurized gas cartridge 50. The free ends of the trigger mechanism 60 are connected to lift rods 53 and return springs 54 that maintain the trigger mechanism 60 in a normal condition where the puncture pin 62 is not in contact with the end of the pressurized gas cartridge 50. Lift rods 53 (only one shown) are connected together and operate in unison to lift the lift plate 55 in a parallel relationship to raise the puncture pin 62 in a linear motion.

[Para 56] FIG. 7 shows a detail cross-sectional view of the puncture pin 62. The puncture pin 62 has a pointed end 61 to puncture the seal on the end of the pressurized gas cartridge 50. A partially hollowed center 65 allows gas or liquidCO2 topass from the pressurized gas cartridge 50 into the chamber 22 of the fire extinguisher 19 even when pin 62 is held in the puncturing position within gas cartridge 50. The puncture pin 62 has a taper 66 to increase the size of the hole as the pin is inserted into the pressurized gas cartridge 50 and the taper 66 provides draft for the pin to readily eject from cartridge 50 via force applies by springs 54. One end of the puncture pin 62 has assembly feature 64 where the puncture pin 62 is retained onto the lift plate 55. An enlarged shank 63 supports the puncture pin 62 between the assembly feature 64 and the partially hollowed center 65. Since the puncture pin 62 is rigidly supported, inadvertent puncturing of gas cartridge 50 during drop event or rough usage is avoided.

[Para 57] Fire extinguishers generally require approval from regulatory agencies such as Underwriters Laboratory (UL). For most fire extinguishers the housing is pressurized. The fire extinguisher disclosed in this document

uses a separate pressurized cartridge 50 that is filled with liquefied gas that must exit the cartridge 50 and expand into the bottom housing 20.

[Para 58] For cartridge-operated extinguishers an interval of 5 seconds is able to elapse after the cartridge is punctured in order that pressure builds up before discharge of the agent is initiated. An extinguisher shall have duration of discharge not less than either 8 seconds, or the minimum duration specified in the Standard for Rating and Fire Testing of Fire Extinguishers.

[Para 59] When the charged extinguisher is held in a vertical position, with the discharge nozzle in the horizontal position. The extinguisher then is to be discharged, and the duration to gas point and amount of dry chemical discharged recorded.

[Para 60] Based upon the ambient temperature and the orientation of the gas canister, different amounts of dry ice (solidC0 2) is retained within aCO 2 cartridge when discharged vertically upward; conversely, a minimum amount of dry ice was retained when discharged vertically downward.

[Para 61] FIG. 8 shows a graph of the amount of Dry Ice that is generated based upon the orientation of the pressurized gas. The graph shows the amount of Dry Ice at the temperatures of 70°F 45 and -40°F 46. At 70°F nearly all orientation positions show that very little Dry Ice is generated. At -40°F the amount of Dry Ice can go from a high of over 40% when the cartridge is in a vertical orientation 47, or about 15% when the cartridge 48 is in a horizontal

48 to almost 0% when the cartridge 50 is inverted 49. The inverted cartridge

pushes liquid C02 out of the cartridge 50 as the liquid within the C02

cartridge 50 of the lighter weight vaporized gas pushes the heavier liquid

within the C02 out of the opening of the cartridge 50 as the cartridge is

engaged 52 into the fire extinguisher 19.

[Para 62] These results were measured when pressurized liquid CO 2

cartridges were conditioned at either 70°F or -40°F and then discharged in

various orientations. Dry ice remaining within the cartridges was measured 30

seconds after puncturing the cartridge.

[Para 63] FIG. 9 shows the fluffing arms 120 and integral siphon tube 112.

In this preferred embodiment the fluffing arms 120 and integral siphon tube

112 are fabricated as a single unit around a central shaft 110. While this

embodiment shows a siphon tube 112 with fluffing arms or blades 120, some

embodiments are contemplated that may not incorporated the fluffing arms or

blades 120. The inclusion of the fluffing arms or blades 120 is generally

dictated by the capacity and rating of the fire extinguisher. The bottom cap

111 of the central shaft 110 fits into the bottom of the fire extinguisher 19.

Seals around the bottom cap 111 prevent pressurized gas from passing out of

the bottom of the fire extinguisher 19. Seals 109 on the upper end of the

central shaft 110 prevent bypass of pressurized gas directly into flow path 80 and eventually out valve 95, leading to reduced range and discharge amount of suppressant material 99. The seals 109 and the seals around the bottom cap 111 allow for the central shaft 110 to be rotated within the fire extinguisher 19. To aide in manufacturing, bottom cap 111, integral siphon tube 112, and/or fluffing arms 120 may be separate parts or combined in any efficient manner.

[Para 64] The integral siphon tube 112 is constructed with an elongated tube member 119 having the blades 120 molded with the elongated tube. A bottom cap 111 is secured to the elongated tube 119 by ultrasonic welding or the like.

[Para 65] 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.

[Para 66] FIG. 10 shows a detail of the multiple intake holes 114 and the fluffing arm(s) 120. The fluffing arms 120 are narrow, crowned, staggered, and tapered 115 to minimize turning resistance while maximizing mixing of packed fire suppressant material 99 and flow of pressurized suppressant material 99 during discharge. Holes 117 in the fluffing arms 120 allow fire suppressant material 99 to pass around the fluffing arms 120 and the support gusset 116. The pressure wave 113 of liquefied gas is shown pushing down on the arm 120. The bottom of the central shaft 110 shows the multiple intake holes 114 where the fire suppressant material 99 is pushed or siphoned into the intake holes 114 and through the integral siphon tube 112 where they can exit the fire extinguisher 19 through the hose 81 and dispensing nozzle 96. The bottom seals exist in recesses in the bottom cap 111 of the central shaft 110. The lower portion 118 of the bottom cap 111 is configured with a head for external gripping with a wheel that allows the central shaft 110 to be rotated externally. In this embodiment the drive is shaped like a "+", but

other shapes are contemplated that will provide essentially equivalent capability.

[Para 67] 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.

INDUSTRIAL APPLICABILITY

[Para 68] The industrial applicability relates to fire extinguishers.

Claims (8)

1. A puncturing mechanism for a portable fire extinguisher, the portable fire extinguisher including a chamber configured to hold a fire suppressant material and a pressurized gas cartridge configured to pressurize the chamber when the portable fire extinguisher is activated by a user, the puncturing mechanism comprising: a safety knob; a lift plate; a puncture pin coupled to the lift plate, the puncture pin configured to puncture the pressurized gas cartridge to release gas therefrom into the chamber of the portable fire extinguisher; and a trigger mechanism coupled to the lift plate, wherein movement of the trigger mechanism from a first position to a second position causes corresponding movement of the lift plate and the puncture pin and causes the puncture pin to rupture the pressurized gas cartridge and release the gas therefrom into the chamber; wherein the safety knob is a rectangular shape having flange portions, wherein horizontal sides of the trigger mechanism are secured with the flange portions of the safety knob when the safety knob is in a horizontal orientation thereby preventing the trigger mechanism from moving from the first position to the second position, the trigger mechanism is allowed to pass by the sides of the safety knob to reach the second position when the safety knob is in a vertical orientation thereby releasing the trigger mechanism.

2. The puncturing mechanism of claim 1, wherein the movement of the trigger mechanism includes a downward movement of the trigger mechanism toward the chamber, and includes an upward movement of the lift plate and puncture pin away from the chamber.

3. The puncturing mechanism of claim 1 or 2, wherein the puncture pin is coupled to a threaded retainer that is configured to receive the pressurized gas cartridge.

4. The puncturing mechanism of any one of claims 1 to 3, wherein the lift plate is biased by a return spring away from the pressurized gas cartridge.

5. A method for activating a portable fire extinguisher, the portable fire extinguisher including a chamber configured to hold a fire suppressant material and a pressurized gas cartridge configured to pressurize the chamber when the portable fire extinguisher is activated by a user, the method comprising: moving a safety knob having flange portions from a first safety knob position where the flange portions lock a trigger mechanism to a second safety knob position causing the flanged portions to allow the trigger mechanism to pass by the sides of the safety knob, thereby releasing the trigger mechanism; and moving the trigger mechanism from a first trigger position to a second trigger position; wherein moving the trigger mechanism includes moving a puncture pin that is coupled to the trigger mechanism to rupture the pressurized gas cartridge and thereby release gas from gas cartridge into the chamber.

6. The method of claim 5, wherein moving the safety knob includes

releasing or ejecting a tamper indicator.

7. The method of claim 5 or 6, wherein moving the first extinguisher

trigger from the first trigger position to the second trigger position includes

moving the trigger mechanism (60) in a first direction, and moving the

puncture pin includes moving the puncture pin in an opposite second

direction.

8. The method of any one of claims 5 to 7, wherein further comprising

using a return spring to bias the puncture pin away from the pressurized gas

cartridge.