Patent Application
20230264058
Exemplary embodiments pertain to the art of fire protection systems, and in particular to firing mechanisms for fire extinguishers of fire protection systems.
In fire protection systems, such as those used in aircraft, fire extinguishers utilize electrical firing cartridges to puncture a burst disk in the fire extinguisher, resulting in the release of extinguishing agent from the fire extinguisher.
In such systems, an electrical pulse is generated and transmitted to the firing cartridge to activate the fire extinguisher. A relatively high current, in some instances 3.5 amps for a pulse duration of 10 to 50 milliseconds is used to activate the firing cartridge. The electrical pulse is transmitted to a bridge wire in communication with an ignition charge, and the bridge wire initiates explosion of the ignition charge by heating the ignition charge to its ignition temperature.
The electrical firing cartridge, however, is prone to issues such as electrostatic discharge and bridge wire corrosion. A high current firing circuit must be designed and installed in a location remote from the firing cartridge and high current electrical conductors are routed from the circuit to each of the fire extinguishers. Such systems are subject to losses and noise which much be accounted for.
In one embodiment, a fire protection system includes a fire extinguisher including a housing. The housing includes an extinguisher outlet and a burst disk. The burst disk configured to retain a volume of fire suppressant material in the housing. A firing cartridge is operably connected to the housing. The firing cartridge includes an output charge, and an ignition charge that, when detonated, causes release of the output charge to rupture the burst disk and release the volume of fire suppressant material through the extinguisher outlet. An optical fiber is configured to transmit a light signal toward the ignition charge to heat and detonate the ignition charge. A light source is operably connected to the optical fiber to transmit the light signal along the optical fiber.
Additionally or alternatively, in this or other embodiments a bridge wire is located between the optical fiber and the ignition charge. The light signal is configured to heat the bridge wire to detonate the ignition charge.
Additionally or alternatively, in this or other embodiments a lens is located between the optical fiber and the bridge wire. The lens is configured to converge the light signal at the bridge wire to heat the bridge wire.
Additionally or alternatively, in this or other embodiments the light source is a laser.
Additionally or alternatively, in this or other embodiments two or more fire extinguishers are operably connected to the light source.
Additionally or alternatively, in this or other embodiments a sensor is operably connected to the light source. The sensor is configured to detect a fire or smoke condition to initiate operation of the light source.
In another embodiment, a method of operating a fire protection system includes providing a fire extinguisher at a selected location. The fire extinguisher includes a housing, the housing includes an extinguisher outlet, and a burst disk. The burst disk is configured to retain the volume of fire suppressant material in the housing. A firing cartridge is operably connected to the housing. The firing cartridge includes an output charge and an ignition charge that, when detonated, causes release of the output charge to rupture the burst disk and release the volume of fire suppressant material through the extinguisher outlet. A light signal is transmitted from a light source along an optical fiber toward the ignition charge, and the ignition charge is heated via the light signal, thereby detonating the ignition charge.
Additionally or alternatively, in this or other embodiments a bridge wire located between the optical fiber and the ignition charge is heated via the light signal, wherein heating of the bridge wire detonates the ignition charge.
Additionally or alternatively, in this or other embodiments the light signal is transmitted through a lens located between the optical fiber and the bridge wire. The lens is configured to converge the light signal at the bridge wire to heat the bridge wire.
Additionally or alternatively, in this or other embodiments the light source is a laser.
Additionally or alternatively, in this or other embodiments two or more fire extinguishers are operably connected to the light source.
Additionally or alternatively, in this or other embodiments a smoke or fire condition is detected via a sensor operably connected to the light source, and operation of the light source is initiated when the smoke or fire condition is detected.
In yet another embodiment, an aircraft includes an aircraft structure, and a fire protection system located in the aircraft structure. The fire protection system includes a fire extinguisher including a housing. The housing includes an extinguisher outlet and a burst disk. The burst disk is configured to retain a volume of fire suppressant material in the housing. A firing cartridge is operably connected to the housing. The firing cartridge includes an output charge, and an ignition charge that, when detonated, causes release of the output charge to rupture the burst disk and release the volume of fire suppressant material through the extinguisher outlet. An optical fiber is configured to transmit a light signal toward the ignition charge to heat and detonate the ignition charge, and a light source is operably connected to the optical fiber to transmit the light signal along the optical fiber.
Additionally or alternatively, in this or other embodiments a bridge wire is located between the optical fiber and the ignition charge. The light signal is configured to heat the bridge wire to detonate the ignition charge.
Additionally or alternatively, in this or other embodiments a lens is located between the optical fiber and the bridge wire. The lens is configured to converge the light signal at the bridge wire to heat the bridge wire.
Additionally or alternatively, in this or other embodiments the light source is a laser.
Additionally or alternatively, in this or other embodiments a sensor is operably connected to the light source. The sensor is configured to detect a fire or smoke condition to initiate operation of the light source.
Additionally or alternatively, in this or other embodiments two or more fire extinguishers are operably connected to the light source.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring now to
A firing cartridge 28 is operably connected to the fire extinguisher 14 such that when the firing cartridge 28 is activated the burst disk 26 is ruptured, and the fire suppressant material 20 flows from the extinguisher housing 18 and through the extinguisher outlet 24.
Referring now to
In the present disclosure, a light signal 34 is utilized to activate the ignition charge 30 The firing cartridge 28 includes a connector housing 36 connected to a cartridge housing 38, and includes an optical fiber 40 along which the light signal 34 is transmitted. The light signal 34 is transmitted through a lens 42 located between the optical fiber 40 and a bridge wire 44 extending across the ignition charge 30. The lens 42 is configured and positioned such that a lens focal point 46 is located at the bridge wire 44, such that the light signal 34 converges at the bridge wire 44 to heat the bridge wire 44 to the ignition temperature of the ignition charge 30. The ignition charge 30 is thus detonated initiating output charge 32 to puncture the burst disk 26 and release the fire suppressant material 20. While in the embodiment of
Referring again to
Fiber optic activation of the fire extinguishers 14 is immune to electrostatic discharge and lightning disruption, and also immune to electromagnetic interference and are unaffected by moisture or gas ingress. Further, optical fibers 40 have a low loss relative to the fiber length, and small size and weight. Further, optical fibers 40 may be utilized safely in environments characterized by hazardous materials and have high sensitivity and have a high degree of long term reliability.
The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.
