FIELD OF THE INVENTION The present invention is an improved cartridge-operated fire extinguishers, both portable and wheel-mounted, of 4 kg to 50 kg and multiples of 50 kg weight.

BACKGROUND OF THE INVENTION There are two main types of fire extinguishers: stored pressure and cartridge- operated. Both types of fire extinguishers contain a propellant gas and a fire fighting agent or extinguishant. The main difference between both types lie in the method of discharge of the propellant and the nature of the extinguishant. The invention is an improved cartridge-operated fire extinguisher.

Cartridge-operated extinguishers contain the propellant gas in a separate cartridge which is punctured or by opening a valve prior to use, ejecting the propellant through a gas tube into the extinguishant, which is then forcefully discharged. They have the advantage of simple and prompt recharge, allowing an operator to discharge the extinguisher, recharge it, and return to the fire in a reasonable amount of time. The propellant could be compressed carbon dioxide or nitrogen or mixture of carbon dioxide and nitrogen.

Most countries in the world have regular fire extinguisher maintenance standards set by a fire and safety authority. Such maintenance standards are set in order for the fire extinguishers to operate safely and effectively, as part of fire safety legislation. Lack of maintenance can lead to an extinguisher not discharging when required, or rupturing when pressurized. Damage to lives and property can occur from badly maintained fire extinguishers and even from corroded extinguishers which can explode.

Three types of maintenance are generally required by fire and safety authorities: Basic Service:

All types of extinguisher require a basic inspection annually to check weight, correct pressure (using a special tool, not just looking at the gauge) and for signs of damage l or corrosion. Cartridge operated extinguishers are opened up for internal inspection & checking of the weight of the extinguishant, labels are checked for legibility, and where possible, tubes, hoses and mechanisms checked for clear free operation. Extended Service

All fire extinguisher need to be inspected annually or bi annually, depending on the fire safety standards of the country.

Water, Wet Chemical, Foam & Powder extinguishers require hydrostatic test and refill every five years or less.a more detailed examination including a test discharge of the extinguisher and recharging.

In recharging the extinguishant, a fresh supply of extinguishant is used as they all have a shelf life. Even water goes foul inside an extinguisher. Some extinguishers contain pressure in excess of 1.38 MPa (200psi) and this internal pressure over periods of time affects each brand & make differently depending on their placement & location.

Overhaul C0 ₂ extinguishers, due to their high operating pressure, are subject to pressure vessel safety legislation and must be hydraulic pressure tested, inspected internally & externally and date stamped every 10 years or less. As valves cannot be pressure tested, a new valve is also fitted. If any part of the extinguisher (valve, horn, etc) is replaced with a part from another manufacturer, the extinguisher will lose its fire rating. This may invalidate insurance, as would incorrect or inadequate servicing if such practices were to be found.

Conventional cartridge-operated fire extinguishers suffer also from these deficiencies:-

1. May be unable to fully discharge contents after inspection.

During inspection, all valves are opened to confirm the existence of powder (especially at the bottom of the cylinder body of the fire extinguisher) and all other parts are in working order. 90% of failures to discharge are due to results of 10 000130 spoilage of the extinguishant powder by mixing be and abc (alkaline and acidity) during refilling. The mixture will cause the extinguishant powder to harden.

External Cartridge-operated fire extinguishers suffer failures to discharge due to the blockage or choking of the gas tube for passage of propellant gas into the body of the cylinder to force the extinguishant out. Such blockages are hard to detect because the design of the cartridge is unfriendly to visual inspections making it impossible to replace even by the manufacturer. For external cartridge- operated fire extinguishers, the gas tube for discharge of propellant is welded on the inside the body of cylinder of the fire extinguisher during manufacturing. The gas tube therefore cannot be inspected.

It is not possible to check whether the propellant gas is blocked in both internal and external cartridge-operated fire extinguishers by using simple devices. Such difficulties in checking arise due to the design of conventional cartridge-operated fire extinguishers.

2. Inability to produce constant flow without a regulator to regulate the pressure.

The most effective range of pressure required to extinguish fires is between 9 to 12 bar. Portable fire extinguishers have never been incorporated with regulators due to their weight and size. However, if a small gas regulator is fitted to a fire extinguisher, it will ensure a constant release of the contents until it is emptied. Fitting of a regulator on fire extinguishers can achieve higher extinguishing capacity/rating compare to one without a regulator. 3. Slow and difficult refilling of conventional fire extinguisher.

Refilling of the conventional cartridge-operated fire extinguisher requires at least 40 minutes if carried out by a skilled worker using a very expensive machine, a motor and few hundred kg in weight of powder. Such refilling operations are difficult or impossible on board an ocean going ship. In particular, according to the marine rules and regulations of SOLAS (SAFETY OF LIFE AT SEA), all extinguishers shall be refilled immediately after use at sea. Most of the crew perform only a "topping up" of the extinguishant in the cartridge-operated fire extinguisher. This is against the fire and safety standards laid down for fire extinguishers. All extinguishant used in fire extinguishers should be completely replaced after partial or complete discharge. 4. Inability to provide nonstop continuous discharge of contents to fight fire.

Most types of fires tend to start small and grow big quickly. It is unfortunate that by the time the fire engines arrive, the fire has grown too large to be placed under control.

In a sea going vessel or in places where help will not be available in a short period of time, once a fire extinguisher is used, it cannot be refilled in a short time. What is desirable is a fire extinguisher which can be refilled quickly and without special tools or training.

5. Lack of automated discharge of the fire extinguisher. Even though fire extinguishers are stored ready for use, a person is required to physically hold the fire extinguisher and direct the contents at a fire.

What is desirable is a fire fighting system comprising of a plurality of fire extinguishers arranged in a systematic manner which can be switched on and are directed at the source of fire. If all the fire extinguishers can be arranged to make a fire fighting system to fight a fire, the combined fire fighting power would be equivalent to the use of an fire engine.

6. Corrosion to the internal steel wall of the cylinder of the fire extinguisher caused by hydrostatic testing which requires direct contact with water.

While the periodic hydrostatic test will ensure fire extinguishers are safe for use, the use of the hydrostatic test in itself will contribute to the eventual corrosion of the internal steel wall of the cylinder of the fire extinguisher.

Various attempts have been made to overcome some of the deficiencies of the conventional fire extinguisher. One approach is to replace the metal cylinder with a plastic container, as proposed by PCT/BR2008/000114 for a fire extinguisher with a disposable plastic container. The plastic container is manufactured with high viscosity Polyamide, Fibreglass and mineral elements in order to withstand the internal pressure to expel its entire contents in a short time. A drawback of this prior art is that the disposable plastic containers must be discarded since it cannot be replaced, reused nor refilled.

The idea of a plastic container inside a fire extinguisher was also proposed in PCT/US2007/019009. However, this invention proposes an aerosol fire extinguisher which is not accepted by most fire and safety bureaus.

What is desirable is an improved cartridge-operated fire extinguisher which can easily solve the tedious refilling operation.

What is also desirable is an improved fire cartridge-operated extinguisher, wherein it can be easily inspected without a need for machines during on the spot inspection. What is further desirable is an improved cartridge-operated fire extinguisher wherein the act of refilling can be visually checked for compliance.

What is also desirable is an improved cartridge-operated fire extinguisher in which the contents of the extinguishant and any blockage of internal valves can be quickly checked by the insertion of a simple hand held device doing away with complicated equipment or where it is impossible to check.

The improved cartridge-operated fire extinguisher of the invention uses a "pre- filled replaceable inner container" which is packed into the cylinder body of the conventional cartridge-operated fire extinguisher. Use of a pre-filled replaceable inner container will ensure the maintenance by users such as ship crew can be easily carried out. This is because refilling the extinguishant into an older used replaceable inner container will actually require more effort than replacing it with a new pre-replaceable inner container. Furthermore with the inventive pre-filled replaceable inner container, replenishment of extinguishant by insertion of a new pre-filled replaceable inner container will be much more convenient. The property owner can also be assured that the fire extinguisher maintenance company or its own maintenance crew is carrying out the maintenance properly. The use of "pre-filled replaceable inner container" for an improved cartridge- operated fire extinguisher replaces the current practice of packaging the spare extinguishant powder on board the ship. The traditional polyurethane powder bags containing extinguishant tend to break easily, exposing the extinguishant to moisture, which then hardens, rendering it useless. Moreover, the quality of the powder can be assured since it is pre-filled by the manufacturer and sealed. The difficulties and problems faced by conventional cartridge-operated fire extinguishers have been overcome by the inventive improved cartridge-operated fire extinguisher.

SUMMARY OF THE INVENTION

A first object of the invention is an improved cartridge-operated fire extinguisher weighing from 4 kg to 50 kg and in multiples of 50 kilos, with an external cartridge connected to the improved fire extinguisher, said external cartridge containing a gas propellant which upon activation, is ejected into an extinguishant which then forces the extinguishant through an outlet hose leading from a hose connection at the neck of the improved cartridge-operated fire extinguisher, the improved cartridge-operated fire extinguisher comprising :- a first hollow cylindrical portion;

a second hollow cylindrical portion; and

a pre-filled replaceable inner container characterised in that the pre-filled replaceable inner container is pre-filled with extinguishant and is packed into the first hollow cylindrical portion and the second hollow cylindrical portion.

A second object of the invention is an improved cartridge-operated fire extinguisher weighing from 4 kg to 50 kg and in multiples of 50 kilos, with an external cartridge connected to the improved cartridge-operated fire extinguisher, said external cartridge containing a gas propellant which upon activation, is ejected into an extinguishant which then forces the extinguishant through an outlet hose leading from a hose connection at the neck of the improved cartridge-operated fire extinguisher, the improved cartridge-operated fire extinguisher comprising:- a first hollow cylindrical portion, said first hollow cylindrical

portion comprising the neck at one end and an opening at the other end; a second hollow cylindrical portion, said second cylindrical portion having an opening at its first end and a closed base at the other end; a securing means to join the first hollow cylindrical portion to the second hollow cylindrical portion; and a replaceable inner container pre-filled with the extinguishant characterised in that the replaceable inner container is packed into the second hollow cylindrical portion through its opening, and the first hollow cylinder fitted into the replaceable inner container, the first end of the second hollow cylindrical portion joined to other end of the first hollow cylindrical portion by the securing means.

Preferably, the first hollow cylindrical portion for an improved fire extinguisher has a flange at the opening at the other end. Preferably, the second hollow cylindrical portion for an improved cartridge- operated fire extinguisher has a flange at the opening at its first end.

Preferably, the flange in the first hollow cylindrical portion for an improved cartridge-operated fire extinguisher has two or more holes spaced apart.

Preferably, the first hollow cylindrical portion for an improved cartridge-operated fire extinguisher, has a hose connection at the neck of the first hollow cylindrical portion for insertion of the outlet hose. Preferably, the first hollow cylindrical portion for an improved cartridge-operated fire extinguisher, has a cylinder valve at the neck of the first hollow cylindrical portion for insertion of an inspectable gas tube.

Preferably, the flange in the second hollow cylindrical portion for an improved cartridge-operated fire extinguisher has two or more holes spaced apart. Preferably, the securing means for an improved cartridge-operated fire extinguisher has two or more nuts and bolts.

Alternatively, the securing means for an improved cartridge-operated fire extinguisher has two or more fasteners.

Alternatively, the securing means for an improved cartridge-operated fire extinguisher has two or more clamps. Alternatively, the improved cartridge-operated fire extinguisher has an opening at the second end of the first portion and an opening at the first end of the second portion which are joined to each other at one point by one or more hinges so that the first portion and the second portion can be unhinged. A third object of the invention for an improved cartridge-operated fire extinguisher is a gas regulator to maintain a constant even flow of the extinguishant upon its release from the outlet.

Preferably, the gas regulator for an improved cartridge-operated fire extinguisher has an inlet valve connected to the cartridge to regulate the flow of gas propellant from the cartridge, and an outlet valve cum inspectable gas tube to regulate the flow of propellant gas.

A fourth object of the invention is an outlet valve cum inspectable gas tube which has a first opening at a first end and a second opening at a second end; the first end of the outlet valve cum inspectable gas tube connected to the regulator and the second end of the outlet valve cum inspectable gas tube protruding inside the replaceable inner container and passing through the neck connection of the first cylindrical hollow portion.

Preferably, the outlet valve cum inspectable gas tube for a gas regulator has a second end of the gas tube which is covered by an one way rubber cover.

Preferably, the outlet valve cum inspectable gas tube for a gas regulator has a first end of the gas tube coupled to the gas regulator by a first compression ring system. Preferably, the outlet valve cum inspectable gas tube for a gas regulator has a second end of the gas tube which is coupled to a second compression ring system. Preferably, the second compression ring system is fitted into the neck connection of the first hollow cylindrical portion.

Preferably, the outlet valve cum inspectable gas tube for a regulator allows the condition of the outlet valve cum inspectable gas tube to be checked by taking out the neck connection, uncoupling the first compression system from the gas regulator, uncoupling the second compression system, taking the outlet valve cum inspectable gas tube and removing the rubber cover, inserting a tip of an air pump into the first end of the outlet valve cum inspectable gas tube and pressing the air pump to force air through the outlet valve cum inspectable gas tube to check for blockage of the outlet valve cum inspectable gas tube.

Preferably, the gas regulator for an improved cartridge-operated fire extinguisher is fitted to improved portable cartridge-operated fire extinguishers. A fifth object of the invention is a method of checking the condition of the outlet valve cum inspectable gas tube comprising the following steps:- removing the neck connection; uncoupling the first compression ring system; uncoupling the second compression ring system; removing the rubber cover at the tip of the first end of the outlet valve cum inspectable gas tube taking out the outlet valve cum inspectable gas tube inserting an air pump into the first end of the outlet valve cum inspectable gas tube pressing the air pump to force air into the outlet valve cum 10 000130 inspectable gas tube of the improved cartridge-operated fire extinguisher; and replacing the outlet valve cum inspectable gas tube if air could not be forced through.

A sixth object of the invention is a replaceable inner container having a body shaped to fit the hollow cylindrical body. Preferably, the replaceable inner container for an improved cartridge-operated fire extinguisher has a body shaped to fit the hollow cylindrical body and a cover for a hole and handle at one end and a puncture point at the other end.

Preferably, the replaceable inner container has a cover for the hole which is removed for filling of extinguishant.

Preferably, the replaceable inner container has a puncture point which is punctured for release of propellant into the extinguishant which is then ejected the _extinguishant out of the replaceable inner container.

Preferably, the replaceable inner container has a handle which is used to lift the replaceable inner container, to remove an used replaceable inner container from the hollow cylinder body or to fit a new replaceable inner container into the hollow cylinder body.

Preferably, the replaceable inner container is made of plastic

Alternatively, the replaceable inner container is made of polyurethane Alternatively, the replaceable inner container is made of fabric which is strong enough to contain up to 50 kilos of extinguishant and is not hygroscopic.

Alternatively, the replaceable inner container is made or any material which is strong enough to contain up to 50 kilos of extinguishant and is not hygroscopic.

A seventh object of the invention is an electric pressure generator on the valve of the improved cartridge-operated fire extinguisher. Preferably, the pyromechanical actuator and valve are wired to a very small power supply of less than 1 amp. Alternatively, the power supply for a pyromechanical actuator for an improved cartridge-operated fire extinguisher is one or more batteries.

Alternatively, the power supply for a pyromechanical actuator for an improved cartridge-operated fire extinguisher is from electrical generators.

Preferably, the improved cartridge-operated fire extinguisher has additionally a controller, a pyromechanical actuator on the valve and electrical wiring to a source of electrical power wherein the improved cartridge-operated fire extinguisher can function as a fire fighting system upon activation by the pyromechanical actuator to discharge the extinguishant automatically and without user intervention .

An eighth object of the invention is a fire fighting system consisting of a plurality of improved cartridge-operated fire extinguishers arranged in a specific configuration in a confined space, said plurality of improved cartridge-operated fire extinguishers connected to each other and to controller, a pyromechanical actuator and electrical wiring to a source of electrical power wherein the improved cartridge-operated fire extinguisher can be activated to discharge the extinguishant automatically and without user intervention.

A ninth object of the invention is a method of refilling an improved cartridge- operated fire extinguisher using the replaceable inner container of the invention, comprising these steps:- turning the improved cartridge-operated fire extinguisher so that the neck of the improved cartridge-operated fire extinguisher is upright; removing the securing means at the flanges; separating the first hollow cylindrical portion from the

second hollow cylindrical portion; removing the replaceable inner container; packing a new replaceable inner container into the second

hollow portion; bringing the first and second hollow cylindrical portions together; securing the first and second hollow cylindrical portions with the securing means; and returning the improved cartridge-operated fire extinguisher to its normal position

A tenth object of the invention is a method of checking whether the improved cartridge-operated fire extinguisher has been refilled after discharge, comprising the following steps:- turning the improved cartridge-operated fire extinguisher so that the neck of the improved cartridge-operated fire extinguisher is upright; removing the securing means at the flanges; separating the first hollow cylindrical portion from the second hollow cylindrical portion; checking the replaceable inner container; bringing the first and second hollow cylindrical portions together; securing the first and second hollow cylindrical portions with the securing means; and returning the improved cartridge-operated fire extinguisher to its normal position

Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realised and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, its advantages, and the objects attained by its use, reference should now be made to the accompanying drawings. The accompanying drawings illustrate one or more embodiments of the invention and together with the description herein, serve to explain the workings and principles of the invention.

FIG. 1A is a cross section view of a cartridge operated water fire extinguisher of the prior art, where the cartridge is located inside the cylindrical body of the fire extinguisher (referred to as " internal cartridge ").

FIG. 1B is a cross section view of a cartridge operated powder fire extinguisher of the prior art, where the cartridge is located externally outside the cylindrical body of the fire extinguisher (referred to as " external cartridge ").

FIG. 2A is a close up of the conventional gas tube leading from an internal cartridge fire extinguisher and which directs the propellant gas into the extinguishant. FIG. 2B is a close up of the conventional gas tube leading from an external cartridge fire extinguisher and which directs the propellant gas into the extinguishant.

FIG. 3 is a cross section view of the improved cartridge-operated fire extinguisher.

FIG. 4 is an expanded cross section view of the improved cartridge-operated fire extinguisher showing the gas regulator, outlet valve cum inspectable gas tube which are the other inventive features of the improved cartridge-operated fire extinguisher. FIG. 5 is a table illustrating the flow rate of extinguishant from an improved cartridge-operated fire extinguisher and from a conventional fire extinguisher.

FIG. 6 is a cross section view of the first step in replenishing the extinguishant in the improved cartridge-operated fire extinguisher.

FIG. 7 is a cross section view of the second step in replenishing the extinguishant in the improved cartridge-operated fire extinguisher. FIG. 8 is a cross section view of the third step in replenishing the extinguishant in the improved cartridge-operated fire extinguisher.

FIG. 9 is a cross section view of the fourth step in replenishing the extinguishant in the improved cartridge-operated fire extinguisher.

FIG. 10 is a cross section view of the fifth step in replenishing the extinguishant in the improved cartridge-operated fire extinguisher.

FIG. 1 1 is a cross section view of the sixth and last step in replenishing the extinguishant in the improved cartridge-operated fire extinguisher.

FIG. 12 is an illustration of how an arrangement of improved cartridge- operated fire extinguishers can be used as a fire fighting system to fight fires on board a sea-going vessel.

FIG. 13 is a cross section view of another embodiment of the improved cartridge-operated fire extinguisher in which the improved cartridge-operated fire extinguisher is modified to fit the replaceable inner container. DETAILED DESCRIPTION OF THE INVENTION

For a better understanding of the invention, its advantages, and the objects attained by its use, reference should now be made to the accompanying drawings. The accompanying drawings illustrate one or more embodiments of the invention and together with the description herein, serve to explain the workings and principles of the invention. Although the following text sets forth a detailed description of one or more exemplary embodiments of the invention, it should be understood that the legal scope of the invention or inventions disclosed herein is defined by the appended claims. The detailed description is to be construed as exemplary only and does not describe every possible embodiment or embodiments of the invention. Numerous alternative embodiments could be implemented using either current technology or technology developed after the filing date of this patent, all of which would still fall within the scope of the claims defining the invention.

Although the main object of the invention is an improved cartridge-operated fire extinguisher which overcome many of the problems associated with conventional cartridge-operated fire extinguishers, the workings of conventional cartridge- operated fire extinguisher will be discussed since much of the workings of the improved cartridge-operated fire extinguishers are similar. FIG. 1A is a cross section view of a cartridge operated water fire extinguisher of the prior art, where the cartridge (5) is located inside the cylindrical body (6) of the fire extinguisher. This type of cartridge operated fire extinguisher is referred to as "internal cartridge fire extinguisher". FIG. 1 B is a cross section view of a cartridge operated powder fire extinguisher of the prior art, where the cartridge (5) is located externally outside the cylindrical body (6) of the fire extinguisher. This type of cartridge operated fire extinguisher is referred to as "internal cartridge fire extinguisher". The cylindrical body (6) is filled with extinguishant in order for it to perform its function. Cartridge-operated fire extinguishers contain the propellant (in gaseous form and under pressure) in a separate cartridge (5) which is punctured/opened prior to discharge. When punctured, the propellant gas will rush through a gas tube leading from the cartridge (5) into the cylindrical body (6) of the fire extinguisher. The cartridge (5) could be located outside the cylindrical body (6) of the fire extinguisher (called "external cartridge") or internally inside the cylindrical body (6) of the fire extinguisher (called "internal cartridge"). They have the advantage of simple and prompt recharge, allowing an operator to discharge the extinguisher, recharge it, and return to the fire in a reasonable amount of time. The propellant gas used in cartridge-operated fire extinguishers could be compressed carbon dioxide, nitrogen or a mixture of carbon dioxide and nitrogen. A discharge mechanism is provided in the fire extinguisher so that when the discharge mechanism is activated, a valve in the neck of the metal cylinder is opened, and at the same time, a disc (as in FIG. 3 and FIG. 12) or a seal (as in FIG. 1 B) holding the propellant gas is broken, releasing the highly pressurized supply of propellant gas. This propellant gas escapes from the cartridge (5), going into a gas tube (3) into the cylindrical body (6) where the extinguishant is stored. The force of propellant gas rushing into the extinguishant stored inside the cylindrical body (6) will push the extinguishant from the cylindrical body (6) into a hose, and then through the nozzle. A safety pin acts as a safeguard against accidental discharge.

It can be seen that the clear passage of propellant gas through the gas tube (3) is crucial to the operation of the fire extinguisher it is to be used. However, the gas tube (3) can be blocked or choked by extinguishant but there is no simple and quick way to check whether the gas tube (3) is choked. Blockage of the gas tube (3) is quite common due to the proximity of the gas tube (3) to the outlet tube through which the extinguishant is forced out. This is shown by the circled portion of FIG. 1 B. FIG. 2A shows a close up view of the construction of the gas tube (4) (for passage of propellant gas) and the powder tube (4) for ejection of extinguishant in a conventional internal cartridge fire extinguisher. The gas tube (3) and the powder tube (4) are usually reinforced together with a metal or jubilee clip (8), because it is easier to insert both tubes simultaneously and thus easier to seal the dry powder fire extinguisher.

When replacing the gas tube (3), the powder tube (4) has to be unscrewed first. While doing this, the metal or jubilee clip (8) will be permanently damaged. Since the existing metal or jubilee clip (8) is permanently formed by using special tools, once the metal or jubilee clip (8) is removed, it will be damaged. Therefore a new metal or jubilee clip (8) has to be fitted into the conventional fire extinguisher after checking. In addition, one of the drawbacks of using the metal or jubilee clip (8) is that it will always be damage by corrosion or jammed by extinguishant powder. The rubber on the gas tube (3) is attached by clamping a metal clip or jubilee clip (8). This design requires a high pressure and complicated pneumatic powered system to blow through the gas tube (3). The problem associated with the gas tube (3) of conventional fire extinguishers be it external or internal cartridge is explained by reference to FIG. 1 B and FIG. 2B. FIG. 2B is a close up view of the circled portion of FIG. 1 B. FIG. 2B shows the construction of the gas tube (3) and the powder tube (4) for ejection of extinguishant for a conventional external cartridge fire extinguisher. The gas tube (3) normally is welded along the wall of the cylindrical body (6) during the manufacturing process of the fire extinguisher. Hence, the external cartridge fire extinguisher will be condemned when the gas tube (3) is choked or damaged.

When the rubber cover (17) is damaged, it has to be replaced by reaching into the cylindrical body (6), whenever possible. If the metal or jubilee clip (8) or the rubber cover (17) cannot be accessed and replaced, the extinguisher will also be condemned.

If the gas tube (3) is attached to the cylindrical body (6) via a threaded joint, the construction will become very complicated and uneconomical (expensive). For example, for some conventional external cartridge fire extinguishers, the metal or jubilee clip (8) is permanently formed by using special tools. Once the metal or jubilee clip (8) is removed, it will be damaged and a new metal or jubilee clip (8) is required. In addition, one of the drawbacks of using the metal or jubilee clip (8) is that it will always be damaged by corrosion or jammed by extinguishant powder. Detailed description of the improved cartridge-operated fire extinguisher

FIG. 3 is a cross section view of the improved cartridge-operated fire extinguisher (1 ). FIG. 4 is an expanded cross section view of the improved cartridge-operated fire extinguisher (1) showing the other inventive features of the improved cartridge- operated fire extinguisher (1):-.

- a gas regulator (15) with an outlet valve cum inspectable gas tube (13); and

- a pyromechanlcal actuator (14) The improved cartridge-operated fire extinguisher (1 ) continues to use the existing 4 kilo to 50 kilo metal cylinders or cylinders in multiples of 50 kg weights. The workings of the improved cartridge-operated fire extinguisher (1 ) remains much the same as conventional cartridge-operated fire extinguishers in that upon activation of the fire extinguisher, a gas propellant passes through an outlet valve cum inspectable gas tube (13) into the pre-filled replaceable inner container (19) of the improved cartridge-operated fire extinguisher (1), forcing the extinguishant out of the improved cartridge-operated fire extinguisher (1).

The main inventive features of the improved cartridge-operated fire extinguisher (1 ) are:- a replaceable inner container (19) pre-filled with extinguishant,

which is packed into the improved cartridge-operated fire extinguisher (1 ) cylindrical body (6); said improved cartridge-operated fire extinguisher (1) cylindrical body (6) consisting of two portions, to accommodate the replaceable inner container ( 9); a gas regulator (15) with an outlet valve cum inspectable gas tube (13); and a pyromechanical actuator (14)

Referring to FIG. 3, it can be seen that the improved cartridge-operated fire extinguisher (1 ) is a conventional metal cylindrical body (6) which now consists of two portions, a first portion and a second portion. Both the first portion and second portion end with flanges which meets when assembled together, and both portions of the cylindrical body (6) are secured to each other with two or more securing means. The securing means may be nuts and bolts (11 ). Alternatively, the securing means could be fasteners. The securing means could also be clamps. The first and second portions can also be connected by a hinge at the connecting flanges and secured by securing means such as two or more nuts and bolts (11 ). The use of two portions allows the replaceable inner container (19) (which is pre-filled with extinguishant) to be packed into the cylindrical body (6) of the improved cartridge-operated fire extinguisher (1 ) in a simple operation. The inventive replaceable inner container (19) is pre-filled with the extinguishant and comes in sizes of 4 kilo to 50 kilo or multiplies of 50 kilo of extinguishant. The use of replaceable inner container (19) pre-filled with extinguishant overcomes many of the drawbacks faced in conventional cartridge-operated fire extinguishers, which had been mentioned earlier. The replaceable inner container (19) may be made of plastic or polyurethane or fabric or any material which is strong enough to contain up to 50 kilos of extinguishant and is not hygroscopic.

The improved cartridge-operated fire extinguisher (1) can be manufactured in two portions, so as to enable the replaceable inner container (19) of extinguishant to be packed into the improved cartridge-operated fire extinguisher (1 ) in a simple operation. Although use of a conventional fire extinguisher in two portions is proposed, the improved cartridge-operated fire extinguisher (1 ) can also be manufactured to fit the shape of the replaceable inner container (19) as shown later on in FIG. 12.

The use of a replaceable inner container (19) will mean there would no longer be any chemical interaction between the extinguishant and the inner walls of the cylindrical body (6) of the improved cartridge-operated fire extinguisher (1 ). There also would not be any contact between the inner walls of the cylindrical body (6) of the improved cartridge-operated fire extinguisher (1 ) and water during hydrostatic tests. This in turn would mean the inner walls are no longer vulnerable to corrosion. Lastly, any corrosion can be easily checked by unscrewing the two portions of the improved cartridge-operated fire extinguisher (1 ) and visually checking the inner walls of the cylindrical body (6).

The other parts of the improved cartridge-operated fire extinguisher (1 ) are similar to conventional fire extinguishers including:-

- compressed gas cartridge

- safety clip

- nozzle

- rupture disc or seal - puncture

- hose

- hose connection/cylinder valve (neck of cylindrical body)

- wheel

- spring

- carry handle (which are the legs of a conventional fire extinguisher).

Gas regulator with outlet valve cum inspectable gas tube Another inventive features to the improved cartridge-operated fire extinguisher (1) is:

- a gas regulator (15) with an outlet valve cum inspectable gas tube (13) The gas regulator (15) ensures a constant flow when the improved cartridge- operated fire extinguisher (1) is activated. The inlet valve of the gas regulator (13) is fitted to the cartridge (5) of the improved cartridge-operated fire extinguisher (1) and the outlet valve fitted to an outlet valve cum inspectable gas tube (13) which leads into the hose connection/cylinder valve of the improved cartridge-operated fire extinguisher (1). The outlet valve cum inspectable gas tube (13) has a first opening at a first end and a second opening at a second end. The first end of the outlet valve cum inspectable gas tube ( 3) is connected to the outlet valve of the gas regulator (15). The outlet valve and inspectable gas tube (13) is made as a single piece, hence it is referred to as "outlet valve cum inspectable gas tube (13)". The second end of the outlet valve cum inspectable gas tube (13) leads to the inside of the replaceable inner container (19) and cylindrical body (6), through the hose connection/cylinder valve [at neck of the improved cartridge-operated fire extinguisher (1 )]. The second end of the outlet valve cum inspectable gas tube (13) passes through the hose connection at the hose connection/cylinder valve, said second end being covered with a one way rubber cover (17).

Currently, gas regulators ( 5) are not fitted on portable cartridge operated fire extinguishers. The inventive feature of the improved cartridge operated fire extinguishers (portable) would improve the performance of portable cartridge operated fire extinguishers, which are more popular. The inventive features are now described in greater details, with reference to FIG. 4, which is an expanded cross section view of the neck of the improved cartridge-operated fire extinguisher (1 ).

A gas regulator (15) fitted into the gas cartridge (5) will control the release of extinguishant, overcoming the problem of varying pressure and thus declining pressure and flow of extinguishant over the duration of fire fighting.

The gas regulator (15) is now described with reference to FIG. 4, in particular the blown up picture of the outlet valve cum inspectable gas tube (13). The gas regulator (15) has an outlet valve which allows the propellant gas to be released at a constant rate. The outlet valve is connected to an outlet valve cum inspectable gas tube (13). A first end of the outlet valve cum inspectable gas tube (13) is connected to the outlet valve of the gas regulator (15) by a first compression ring system coupling (23). A second end of the outlet valve cum inspectable gas tube (13) is connected by a second compression ring system coupling (24) to the hose connection/cylinder valve of the improved cartridge- operated fire extinguisher (1). The second end of the outlet valve cum inspectable tube (13) opens to the inside of the cylindrical body (6) and replaceable inner container (19). To prevent the extinguishant from going into the opening of the second end, a rubber cover (17) which serves as a one way valve is placed at the opening of the second end.

This inventive gas regulator (15) with outlet valve cum inspectable gas tube (13) serves to transfer propellant gas from the cartridge (5) to the replaceable inner container (19) at a constant rate. It also offers a quick and simple way to check the contents of the replaceable inner container (19) as well as whether there is any blockage in the outlet valve cum inspectable gas tube (13) itself.

If a quick check of the workings of the extinguishant and outlet valve cum inspectable gas tube (13) is initiated, the hose connection/cylinder valve at the neck of the improved cartridge-operated fire extinguisher (1) is unscrewed. The hose connection/cylinder valve and outlet valve cum inspectable gas tube (13) is then removed from the replaceable inner container (19). The first compression ring system coupling (23) at the first end of the outlet valve cum inspectable gas tube (13) to the gas regulator (15) is then unscrewed. Likewise, the second compression ring system coupling (24) to the second end of the outlet valve cum inspectable gas tube (13) is also unscrewed. The rubber cover (17) at the tip of the second end of the outlet valve cum inspectable gas tube (13) is then removed. The outlet valve cum inspectable gas tube (13) is then taken out from the hose connection/cylinder valve. An air pump (25) can be pushed into the first end of the outlet valve cum inspectable gas tube (13). The air pump (25) is then pressed so that air is forced through the outlet valve cum inspectable gas tube (13). If air cannot be forced through, it would indicate a blockage of the outlet valve cum inspectable gas tube (13). With the outlet valve cum inspectable gas tube (13), any person can check by blowing through the outlet valve cum inspectable gas tube (13) using a simple air pump (25). A simple way to check the workings of the improved cartridge- operated fire extinguisher (1) is achieved. Furthermore, this quick and simple check can be carried out without the need for specialised equipment and can be checked by untrained personnel.

The inventive feature of an outlet valve cum inspectable gas tube (13) connected to the gas regulator (15) will overcome the problem associated with inspection of the gas tube (3) of conventional fire extinguisher, such as:- inability to fully discharge the contents. inability to replace gas tube (3) if there is a blockage of gas tube (3). inability to blow though the gas tube (3) to check for blockages.

FIG. 5 is a table illustrating the flow rate of extinguishant from an improved cartridge-operated fire extinguisher (1 ) and from a conventional fire extinguisher.

Pyromechanical actuator

The inclusion of a simple pyromechanical actuator (14) on the valve of the improved cartridge-operated fire extinguisher (1 ) is to automatically open the valve when switched on. The pyromechanical actuator (14) and valve are wired to a very small power supply of less than 1 amp. With the use of the pyromechanical actuator (14), the improved cartridge-operated fire extinguisher (1) can now be turned on and off automatically. The device of the pyromechanical actuator (14) is useful when a number of improved cartridge-operated fire extinguishers (1 ) are arranged for fire fighting purpose, allowing all the improved cartridge-operated fire extinguishers (1) to be operated automatically. Re-filling process of the Improved cartridge-operated fire extinguisher

FIG. 6 to FIG. 1 are cross section views of the first step until the 6 ^th (last) step in replenishing the extinguishant in the improved cartridge-operated fire extinguisher (1 ).

Referring to FIG. 6, if the cylindrical body (6) has to be refilled, the improved cartridge-operated fire extinguisher (1) is now turned over by gripping its carry handle (10). When the improved cartridge-operated fire extinguisher (1 ) is turned over, it will be standing on its conventional legs [which in the improved cartridge- operated fire extinguisher (1 ) acts as the carry handle (10)].

Referring to FIG. 6, the two or more nuts and bolts (11 ) which joined both portions at their flanges are taken out. The first portion is then separated from the second portion of the cylindrical body (6). In FIG. 6, the first portion of the cylindrical body (6) of the improved cartridge-operated fire extinguisher (1 ) has been removed and therefore not shown. The used replaceable inner container (19) is shown still packed inside the walls of the second portion of the improved cartridge-operated fire extinguisher (1). Referring to FIG. 7, the used replaceable inner container (19) is now removed from the second portion of the improved cartridge-operated fire extinguisher (1 ). The used replaceable inner container (19) is now shown separated from the second portion of the improved cartridge-operated fire extinguisher (1 ). With reference to FIG. 8, the second portion of the improved cartridge- operated fire extinguisher (1 ) is now packed with a fresh replaceable inner container (19), pre-filled with extinguishant.

With reference to FIG. 9, the first portion of the improved cartridge-operated fire extinguisher (1 ) is now fitted onto the second portion at their flanges. The two or more nut and bolts (11 ) are inserted into the flange and tightened, closing the improved cartridge-operated fire extinguisher (1) tightly. Once the replaceable inner container (19) is placed onto the second portion, the first portion is placed on top of the replaceable inner container (19), secured to the second portion by the flange, and tightened by the one or more nuts and bolts (1 ). It can be seen that use of a pre-filled replaceable inner container (19) makes the task of re-filling an improved cartridge-operated fire extinguisher (1) so much easier. No special tools nor machine is required except for normal tools to remove the nut and bolt (11 ) at the flange. Once the nut and bolt (11 ) are removed, the first portion can be separated from the second portion, exposing the pre-filled replaceable inner container (19).

The 6 and final step is shown in FIG. 10. The improved cartridge-operated fire extinguisher (1) is now turned over (with the stand facing upwards). The improved cartridge-operated fire extinguisher (1 ) in its normal position is therefore opposite to the conventional fire extinguisher in its normal position.

Description of the workings of the Improved cartridge-operated fire extinguisher

When the improved cartridge-operated fire extinguisher (1) is used to fight a fire, its operations would be identical as if a conventional fire extinguisher is used. Since the improved cartridge-operated fire extinguisher (1 ) is on a wheel, it can be pushed to the location of the fire.

However, with the improvements, the improved cartridge-operated fire extinguisher (1 ) works in a slightly different and more effective manner: a. The safety clip is removed, the rupture disc in the cartridge (5)

is broken by puncturing (if it is a seal) or by opening the valve (if it is a disc) in the cartridge (5).

The pressure and flow of propellant into the replaceable inner container (19) containing the extinguishant is now regulated because of the use of the gas regulator (15).

The propellant rushes out through the outlet valve cum inspectable gas tube (13), exiting through the second opening, passing through the rubber cover (17) which acts as a one way valve, preventing backflow of the .extinguishant.

The propellant upon entering the replaceable inner container (19) forces the extinguishant out through the outlet hose, ejecting the extinguishant through the nozzle of the hose.

With the use of a gas regulator (15), the pressure from the improved cartridge- operated fire extinguisher (1 ) will be evenly controlled. The extinguishant is therefore ejected in a steady jet, at a controlled even pressure thereby ensuring a constant release of the contents until it is emptied. The performance of an improved cartridge-operated fire extinguisher (1) and that of a conventional fire extinguisher is illustrated in FIG. 5. For refilling or replacement of extinguishant, referring to FIG. 6 to FIG. 11 again, the improved cartridge-operated fire extinguisher (1 ) is now turned with its neck facing upwards. The nuts and bolts (11 ) at the flanges of the improved cartridge-operated fire extinguisher (1 ) is removed. The first portion of the cylindrical body (6) removed. The used replaceable inner container (19) is removed and a new replaceable inner container (19) pre-filled with extinguishant is packed into the second portion. The first portion of the cylindrical body (6) is then placed onto the second portion and the nut and bolt ( 1) tightened at the flanges, thus forming the improved cartridge-operated fire extinguisher (1). The task of packing the replaceable inner container (19) into the improved cartridge-operated fire extinguisher (1 ) can be carried out by anyone. The use of the improved cartridge-operated fire extinguisher (1) is thus advantageous for ocean going vessels as the seamen can carry out the repacking of the prefilled plastic container into the improved cartridge-operated fire extinguisher (1 ).

The improved cartridge-operated fire extinguisher (1 ) will also enable property owners to check whether refilling had been carried out since the fire extinguisher technician can be simply refill in front of him. Furthermore, the refilling process is swift and can be very easily verified by anyone. With such a simple operation, the task of checking the contents of the fire extinguisher and the task of refilling the fire extinguisher is completed, without the need for special tools nor technical training. The improved cartridge-operated fire extinguisher (1 ) has been described as comprising of two portions, connected to each other at the flanges and secured by nuts and bolts (11 ). It is possible for the first portion and second portion to be connected at the flanges by a hinge and secured by nuts and bolts (11 ). The proposed replaceable inner container (19) containing pre-filled extinguishant will also serve as a back up instead of traditional polyurethane powder bags containing the extinguishant which requires special tools and trained personnel to carry out the refilling operations. The use of the replaceable inner container (19) pre-filled with extinguishant will do away with inadequacies of the current inspection requirements for fire extinguishers:- inability to discharge its entire contents even after inspection caused by spoilage of the extinguishant powder;

need for specialised machines to carry out the checking of pressure; inability to check the internal walls of the cylinder for rust - slow refilling of extinguishant by trained personnel using specialised machines;

- inability to automatically discard the amount of extinguishant remaining in the cylinder during refilling.

Fig. 12 is an illustration of how an arrangement of improved cartridge-operated fire extinguishers (1 ) can be used as a fire fighting system to fight fires on board a sea-going vessel.

With the improved cartridge-operated fire extinguisher (1 ), a team of 5 man or more and using 4 units of 25 or 50 kg improved cartridge-operated fire extinguisher (1 ) and one man to pass the spare refill can provide a nonstop fire fighting ability similar to a fire engine. Therefore if an array of improved cartridge-operated fire extinguishers (1 ) are laid out, say in the engine room of a ocean going vessel or any room to be protected in a building. The array of fire extinguishers are connected by wires to an electrical switch, the array of improved cartridge-operated fire extinguishers (1 ) can become a fire fighting system for the particular area, such as the engine room. Should a fire breaks out, all the improved cartridge-operated fire extinguishers (1) in the array can be switched on all at once. The extinguishant can then be directed towards the engines to snuff out any fire.

Furthermore, if the spare refill is packed in standard replaceable inner container (19) which in turn can be packed into a standard pallet, re-filling of the improved cartridge-operated fire extinguishers (1 ) would be very easy. Since the pre-filled replacable inner container (19) of the improved cartridge-operated fire extinguisher (1) is air tight being sealed by the powder manufacturer, there will be no chance for users of such fire extinguishers to complain that the powder was spoilt during refilling or during storage.

The inclusion of a simple pyromechanical actuator (14) on the valve of the cartridge (5) will enable the valve to open automatically when switched on. The pyromechanical actuator (14) and valve are wired to a very small power supply of less than 1 amp. With the use of the pyromechanical actuator (14), the improved cartridge-operated fire extinguisher (1 ) can now be turned on and off automatically. Therefore if a number of improved cartridge-operated fire extinguishers (1) are placed together in a confined space, these can function as a fire fighting system.

A plurality of improved cartridge-operated fire extinguishers (1 ) are placed at spaced intervals along a wall of a room in a sea going _, vessel. Therefore if an array of improved cartridge-operated fire extinguishers (1) are laid out, say in the engine room of an ocean going vessel, or room to be protected in a building and connected by wires to an electrical switch, the array of improved cartridge-operated fire extinguishers (1 ) can become a fire fighting system for the particular area, such as the engine room. Should a fire breaks out, all the improved cartridge-operated fire extinguishers (1) in the array can be switched on all at once. The extinguishant can then be directed towards the engines to snuff out any fire. Each of the improved cartridge-operated fire extinguishers (1) are connected to a 9V battery power supply and wired to each other and to a manual switch. Should a fire break out and the situation warrants the activation of this fire fighting system, the door of the room is shut and the manual switch set to on. Each of the improved cartridge-operated fire extinguisher (1 ) would be activated through the pyromechanicall actuator (14). The extinguishant would be directed at the source of fire. With all improved cartridge-operated fire extinguishers (1) directed at the source of fire, the fire would be contained. The improved cartridge-operated fire extinguishers (1) to form a fire fighting system for a confined space in a sea going vessel or even in offices which do not have any fire system or in case of a failure of existing fire system.

FIG. 13 shows a second embodiment of the improved cartridge-operated fire extinguisher (1 ) wherein the cylinder of the improved cartridge-operated fire extinguisher (1 ) is modified to fit the form and shape of the replaceable inner container (19). In this second embodiment, the cylinder of the improved cartridge- operated fire extinguisher (1 ) not only fits the replaceable inner container (19) but is modified to suit the replaceable inner container (19), having these inventive features:- a. a hole for filling of extinguishant by the powder manufacturer directly, ensuring quality control; b. a handle for the said replaceable inner container (19), enabling it to be easily handled. c. shaped to fit the chemical inlet; d. has the checking means which is the outlet valve cum inspectable gas tube (13) connected to the gas regulator (15) which allows for quick check of the contents of the said replaceable inner container (19); and shaped to fit puncture device to puncture said replaceable inner container (19) at the bottom of the improved cartridge-operated fire extinguisher (1 ) to allow chemical to rush into the discharge hose. Nonetheless the essence of the second embodiment is still a replaceable inner container (19) pre-filled with extinguishant which is fitted into the hollow cylindrical body (6) of the improved cartridge-operated fire extinguisher (1 ). Again, the hollow cylindrical body (6) of the improved cartridge-operated fire extinguisher (1 ) consists of a first portion and a second portion, which is joined to each other at their flanges and tightened by securing means, in the form of one or more nuts and bolts (11 ). The replaceable inner container (19) may be made of plastic or polyurethane or fabric or any material which is strong enough to contain up to 50 kilos of extinguishant and is not hygroscopic.

Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiment as described herein, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the claims.

ADVANTAGEOUS EFFECTS OF THE INVENTION

The improved cartridge-operated fire extinguisher (1 ) can overcome the deficiencies of conventional fire extinguishers:-

1. Inability to discharge its entire contents even after inspection.

2. Inability to produce constant flow

3. Slow refilling of conventional fire extinguisher.

4. Inability to provide nonstop continuous discharge of contents to fight fire.

5. Lack of automated discharge of the fire extinguisher.

6. Corrosion to the internal steel wall of the cylinder of the fire extinguisher caused by Hydrostatic testing Compliance with fire safety regulations with the improved cartridge-operated fire extinguisher (1 ) would be easier and at the same time, make it easier for someone to inspect whether a fire extinguisher had been refilled.