CARTRIDGE-OPERATED FIRE EXTINGUISHER

Abstract

A cartridge-operated fire extinguisher comprising a gas cartridge 124 for storing pressurised fluid 126 therein, and a spear 150 moveable from an initial first position in a first direction to pierce the gas cartridge 124, and moveable in a second direction to a second position to thereby indicate that pressurised fluid 126 has been released from the gas cartridge 124.

Claims

1. A cartridge-operated fire extinguisher comprising: a gas cartridge (124) for storing pressurised fluid (126) therein; and a spear (150) moveable from an initial first position in a first direction to pierce the gas cartridge (124), and moveable in a second direction to a second position to thereby indicate that pressurised fluid (126) has been released from the gas cartridge (124).

2. A cartridge-operated fire extinguisher as claimed in claim 1, comprising: a valve body (104) comprising a socket (130), wherein the gas cartridge (124) is installed in the socket (130); and a pressure chamber (138) in fluid communication with the socket (130), wherein the spear (150) is disposed partially within the pressure chamber (138) and is configured to move in the second direction when pressure in the pressure chamber (138) exceeds a predetermined pressure threshold.

3. A cartridge-operated fire extinguisher as claimed in claim 1 or 2, wherein the spear (150) comprises a marker (156) at an end distal from the gas cartridge (124), which marker (156) is visible only when the spear (150) is in the second position.

4. A cartridge-operated fire extinguisher as claimed in claim 3, wherein the spear (150) comprises a seal (156), and wherein the seal (156) provides the marker.

5. A cartridge-operated fire extinguisher as claimed in any preceding claim, comprising a window (170) arranged so that the distal end (152) of the spear (150) is visible through the window (170) when the spear (150) is in the second position.

6. A cartridge-operated fire extinguisher as claimed in any preceding claim, wherein the spear (150) comprises a flange (158) arranged to abut a shoulder of the fire extinguisher when the spear (150) is in the second position.

7. A cartridge-operated fire extinguisher as claimed in any preceding claim, comprising a biasing element (160) arranged to bias the spear (150) away from the gas cartridge (124).

8. A cartridge-operated fire extinguisher as claimed in any preceding claim, configured so that the spear (150) remains in the second position during release of fire suppressant (122) from the fire extinguisher.

9. A cartridge-operated fire extinguisher as claimed in any preceding claim, comprising an activation lever (114), wherein the spear (150) is spaced from the activation lever (114) when it is in the first position.

10. A method of indicating a status of a cartridge-operated fire extinguisher, comprising using pressurised fluid (126) from a gas cartridge (124) of the fire extinguisher (100) to actuate a spear (150) from an initial first position to a second position to thereby indicate that pressurised fluid (126) has been released from the gas cartridge (124).

11. A method as claimed in claim 10, comprising actuating the spear (150) in a first direction to pierce the gas cartridge (124) and thereby release pressurised fluid (126) from the gas cartridge (124).

12. A method as claimed in claim 10 or 11, wherein actuating the spear (150) from the first position to the second position comprises pressurising a pressure chamber (138) in a valve body (104) of the fire extinguisher (100) to greater than a predetermined pressure threshold.

13. A method as claimed in any of claim 10, 11 or 12, comprising maintaining the spear (150) in the second position while fire suppressant (122) is discharged from the fire extinguisher (100).

14. A method as claimed in any of claims 10 to 13, comprising using the cartridge-operated fire extinguisher (100) of any of claims 1 to 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Certain embodiments of the invention are described below by way of example only and with reference to the accompanying drawings in which:

[0050] FIG. 1 shows a cartridge-operated fire extinguisher;

[0051] FIG. 2 shows a cross-section through the cartridge-operated fire extinguisher of FIG. 1;

[0052] FIG. 3 shows a cross-section of a portion of the fire-extinguisher of FIGS. 1 and 2, including a spear in a first position;

[0053] FIG. 4A shows the portion of FIG. 3 from an alternative view point;

[0054] FIG. 4B shows the portion of FIG. 3 from an alternative view point and with some elements of the fire extinguisher transparent;

[0055] FIG. 5 shows a cross-section of the portion of the fire-extinguisher of FIGS. 1 and 2, including the spear in a second position;

[0056] FIG. 6A shows the portion of FIG. 5 from an alternative view point; and

[0057] FIG. 6B shows the portion of FIG. 5 from an alternative view point and with some elements of the fire extinguisher transparent.

DETAILED DESCRIPTION OF THE INVENTION

[0058] FIG. 1 shows a cartridge-operated fire extinguisher 100. The fire extinguisher comprises a cylinder 102 (or housing) for containing fire suppressant 122, a valve body 104 closing the cylinder 102, a hose connector 106, and a hose 108 connected to the valve body 104 via the hose connector 106. The valve body 104 is mounted on a top of the cylinder 102 to thereby seal cylinder 102. The hose connector 106 is connected to the valve body 104, and the hose 108 is connected to the hose connector 106. In this way, the hose 108 is fluidly connected to a fluid volume 120 within the cylinder 102, and may be used to discharge fire suppressant 122 from the fluid volume 120 in order to combat a fire (provided the fluid volume 120 is suitably pressurised).

[0059] The hose 108 comprises a handle 110 and a nozzle 112. An activation lever 114 is connected to the valve body 104 and is operable to activate the fire extinguisher 100 by pressurising the fluid volume 120 as described herein. When the fire extinguisher 100 is not in use, the hose 108 may be mounted on to the activation lever 114 in a storage position. Of course, the hose 108 and handle 110 may be stored in any suitable manner. The hose 108 may be unclipped from the activation lever 114 and directed at a fire during use of the fire extinguisher 100, to thereby direct fire suppressant 122 as it is discharged from the fluid volume 120.

[0060] FIG. 2 shows a cross-section through the cartridge-operated fire extinguisher 100 of FIG. 1. The cylinder 102 defines the fluid volume 120 therein, and a fire suppressant 122 is stored within the fluid volume 120. The fire suppressant 122 may be dry powder, liquid, water or any other suitable fire suppressant 122 as required. The cylinder 102 also houses a gas cartridge 124, which gas cartridge 124 is connected to a socket 130 of the valve body 104 so as to be in fluid communication with the fluid volume 120 when it is open. The cartridge 124 comprises a propellant 126 such as pressurised gas. The pressurised fluid propellant 126 in the gas cartridge 124 may be any suitable propellant and may be stored in any suitable state (e.g. gas and/or liquid). The propellant 126 may be carbon dioxide. When the cartridge 124 is opened pressurised fluid propellant 126 will leave the cartridge 124 and flow into the fluid volume 120 to thereby pressurise the fluid volume 120. Fire suppressant 122 may then be sprayed out of the pressurised fluid volume 120 via the valve body 104 and through the hose 108. A dip tube 128 may be provided to supply the suppressant 122 to the valve body 104. A blow pipe may also be provided e.g. where a powder suppressant is used to communicate the propellant 126 from the gas cartridge 124 to the fluid volume 120 and help aerate and agitate the powder.

[0061] To open the gas cartridge 124, the fire extinguisher 100 comprises a spear 150 housed within a bore 132 of the valve body 104. The spear 150 is configured to actuate towards the gas cartridge 124 in a first direction, to thereby pierce the gas cartridge 124 e.g. pierce a frangible membrane, a rupture disc, or the like. The spear 150 is also operable to move in a second direction to a second position. The activation lever 114 may be operated by a user in order to drive the spear 150 in the first direction and thereby activate the fire extinguisher 100. For example, a protrusion 115 of the activation lever 114 may contact a distal end 152 of the spear 150 when the activation lever 114 is operated by a user, and thereby drive the spear 150 towards the gas cartridge 124. A gap may be provided between the protrusion 115 and the distal end 152 of the spear 150 so that the when the spear 150 is in the first position.

[0062] When the gas cartridge 124 is pierced by movement of the spear 150 in the first direction (typically downwards), the propellant 126 is released through the socket 130 of the valve body 104 into the fluid volume 120 of the cylinder 102. The dip tube 128 is configured to then provide the fire suppressant 122 to the valve body 104, the hose connector 106, and through the hose 108. The nozzle 112 of the hose 108 may then be directed by a user using the handle 110, towards a fire for extinguishing the fire.

[0063] Thus, the fire extinguisher 100 may be primed for use by actuation of the spear 150 from the initial first position in the first direction to penetrate the gas cartridge 124 and thereby cause propellant 126 to be released and hence to pressurised the fluid volume 120. The cartridge 124 may comprise a frangible seal, rupture disc, membrane or the like arranged to be broken by the spear 150. Any suitable arrangement may be provided in which the spear 150 is driven to make a hole in the cartridge 124 to release propellant 126.

[0064] FIG. 3 shows a portion of the fire extinguisher 100 comprising the valve body 104, and the spear 150 in the initial first position. A distal end 152 of the spear 150 (i.e. the end furthest from the cartridge 124) is within the bore 132 of the valve body 104 e.g. flush. A marker seal 156 of the spear 150 is disposed inside the bore 132, and is therefore not visible e.g. by a user or service technician. The marker seal 156 cooperates with a circumferential recess 134 in the bore 132 to hold the spear 150 in the initial first position. The marker seal 156 is an O-ring and is coloured so as to be readily visually distinguishable from the rest of the of the spear 150.

[0065] In the depicted fire extinguisher 100, the seal 156 serves as both a seal to help reduce leakage past the spear 150, and a visual marker, but it will be appreciated that any suitable marker may be provided in addition to, or instead of, the seal 156. The spear 150 may comprise a plurality of seals (see e.g. second seal 157 in FIG. 3) so that when the spear 150 moves to the second position sufficient sealing is still provided.

[0066] The spear 150 is maintained in the initial first position in the bore 132 by interaction of the marker seal 156 with the recess 134. The seal 156 is seated partially within the recess 134. Thus, in order to move the spear 150 from the first position, a sufficient force greater than a predetermined force threshold must be applied to cause the marker seal 156 to deform and move out of the recess 134. It may also be necessary to overcome a force from the second seal 157, as desired. In short, the spear 150 must be pushed hard enough to make it move from the first position. The spear 150 is therefore held in the first position unless it is subjected to a force greater than the predetermined force threshold. The shape of the seal 156 and the recess 134 can be selected so as to determine the predetermined force threshold.

[0067] The activation lever 114 is operable to apply a sufficient force to the spear 150 to move it in the first direction towards the gas cartridge 124. During use, the activation lever 114 is actuated downwards (e.g. by hand) which causes the spear 150 to move, thereby driving a proximal end 154 of the spear 150 (i.e. the end closest to the cartridge 124) in the first direction to pierce the top of the gas cartridge 124. The proximal end 154 of the spear 150 may be shaped for piercing the gas cartridge 124. Propellant 126 is thereby released from the gas cartridge 124 and pressurises the fluid volume 120. A valve element (or any other suitable mechanism) may then open the fluid volume 120, so that entrained fire suppressant 122 is discharged from the pressurised fluid volume 120 of the fire extinguisher 100. The valve element may be disposed in the handle 110, the valve body 104, or any suitable location as required.

[0068] A spring 160 is disposed between the gas cartridge 124 and the spear 150, and may abut a flange 158 of the spear 150. The spring 160 therefore biases the spear 150 away from the cartridge 124, and may be operable to move the spear 150 away from the cartridge 124 once the spear 150 has pierced the gas cartridge 124. This may help ensure that propellant 126 quickly exits the cartridge 124 to charge the fluid volume 120, since the spear 150 will not block the hole it makes in the cartridge 124.

[0069] The spring 160 may be arranged so that it only moves the spear 150 a portion of its travel away from the gas cartridge 124. The spring 160 may not be arranged to move the spear to the first position.

[0070] The spear 150 may comprise a fluid channel 159 running along at least a portion of its length proximate the proximal end 154 (i.e. the end nearest the cartridge 124). The fluid channel 159 ensures that the spear 150 will not fully block the hole it makes in the cartridge 124 even when partially disposed in the cartridge 124 so that propellant 126 can quickly exit the cartridge 124 after it is punctured. The spear 150 may comprise a plurality of such fluid channels 159.

[0071] FIG. 4A shows another view of the portion of the fire extinguisher 100. The valve body 104 comprises a window 170 through which the distal end of the spear 150 (and e.g. the marker seal 156) may be visible when the spear 150 is in its second position. A user or a service technician may look through the window 170 to check the position of the spear 150, and thereby check the status of the gas cartridge 124. The spear 150 is not visible in the configuration shown in FIG. 4A.

[0072] FIG. 4B shows the same portion of the fire extinguisher 100 with transparent elements, with the spear 150 in the initial first position so that the seal 156 is within the bore 132 and therefore not visible. In this configuration, the fire extinguisher 100 is ready to be activated by a user.

[0073] The valve body 104 comprises a pressure chamber 138 immediately downstream of the gas cartridge 124 and upstream of the fluid volume 120. The spear 150 is partially disposed in the pressure chamber 138 and is therefore exposed to fluid pressure therein. Propellant 126 leaving the gas cartridge 124 therefore pressurises the pressure chamber 138, and when the pressure reaches a predetermined pressure threshold it causes the spear 150 to move in the second direction (opposite the first direction) away from the gas cartridge 124. Thus, the spear 150 moves upwards to the second position wherein the flange 158 contacts a shoulder of the valve body 104 e.g. the edge of the pressure chamber 138, and therefore prevents the spear 150 from moving any further in the second direction. The marker seal 156 therefore exits (e.g. pops out) of the bore 132 and becomes visible when the spear 150 is in the second position. The second seal 157 can maintain sufficient sealing when the spear 150 is in the second position. The window 170 in the valve body 104 ensures that the distal end 152 of the spear 150 is visible through the valve body 104. Thus, a user or service technician can conclude that the gas cartridge 124 has opened (and hence that the fluid volume has been pressurised) when the marker seal 156 of the spear 150 is visible.

[0074] FIG. 5 shows the spear 150 in the second position, with the marker seal 156 outside the bore 132 and therefore visible e.g. through the window 170 of the valve body 104. The spear 150 moves to the second positon when pressure in the pressure chamber 138 exceeds a predetermined pressure threshold and thereby applies a sufficient force to the spear 150. The fire extinguisher 150 is configured so that the spear 150 will only move to the second position if pressure within the pressure chamber 138 exceeds the predetermined pressure threshold. The predetermined pressure threshold may be selected as needed e.g. as that below which the fire extinguisher 100 is safe to disassemble. The predetermined pressure threshold may be above atmospheric pressure. The predetermined pressure threshold may be 1 MPa (Megapascal), 1.5 MPa, 2 MPa, 5 MPa, 7 MPa, 10 MPa, 15 MPa or 20 MPa. The predetermined pressure may be that typically required to suitably pressurise the fluid volume 120 for release of suppressant 122.

[0075] In addition to being moved in the second direction after piercing the cartridge 124, the spear 150 may move in the second direction without first moving in the first direction e.g. in the event that the gas cartridge 124 leaks and thereby pressurises the pressure chamber 138. A service technician can therefore readily determine if the gas cartridge 124 has leaked just by a visual inspection of the spear 150. Indeed, the fire extinguisher comprises a safety clip 175 which needs to be removed or broken in order to move the activation lever 114 and thereby activate the fire extinguisher 100. The condition of the safety clip 175 may also be visible to a user or a service technician, and can therefore provide another indicator of the condition of the fire extinguisher 100.

[0076] For example, if the safety clip 175 remains in place or in one piece, but the spear 150 is in the second position then it is likely that the activation lever 114 was not moved, but the pressure chamber 138 is nevertheless pressurised, and hence likely that the gas cartridge 124 has leaked. If the spear 150 is in the second position, and the safety clip 175 has been broken, then it is likely that the gas cartridge 124 was punctured by the spear 150. If the safety clip 175 is in place, and the spear 150 is not in the second position, then the fire extinguisher 100 is likely ready to be activated e.g. in the event of a fire. Thus, the condition of the safety clip 175 together with the status of the spear 150 can be used to determine whether the gas cartridge 124 is sealed, has been opened by use of the activation lever 114, or has leaked.

[0077] The gap between the distal end 152 of the spear 150 and the protrusion 115 of the activation lever 114 when the spear 150 is in the first position therefore permits movement of the spear 150 in the second direction. That is, there is space for the spear 150 to pop out when the pressure chamber 138 is pressurised.

[0078] FIG. 6A shows the fire extinguisher 100 with the spear 150 in the second position i.e. popped out from the bore 132. The distal end 152 of the spear 150 and the marker seal 156 are visible through the window 170, and hence the gas cartridge 124 has been opened. Further, the safety clip 175 is in place, and hence it is likely that the lever 114 did not move, and rather the gas cartridge 124 has leaked in order to pressurise the pressure chamber 138.

[0079] FIG. 6B shows the same configuration as that of FIG. 6A, but with parts of the fire extinguisher transparent. Again, the spear 150 has moved to the second position and therefore protrudes from the bore 132 of the valve body 104 so that the marker seal 156 is visible. The second seal 157 maintains sufficient sealing of the spear 150 in the bore 132.

[0080] The spear 150 therefore provides two functions. Firstly, it is operable to pierce the gas cartridge 124 and thereby make the fire extinguisher 100 ready for use by pressurising the fluid volume 120. It is also operable to move to its second position to thereby show that the fire extinguisher 100 is pressurised.