Abstract:
A cargo container fire suppression system may prevent fires from spreading within a cargo area into other portions of a craft. A fire resistant liner may be disposed within a cargo container to prevent a fire from penetrating through the liner and burning other elements within the craft beyond the wall(s) of the liner. The suppression system may include a fire sensor and an automatic fire extinguishing device. A transceiver may be coupled to the fire sensor which may remotely alert personnel to a fire occurring in the cargo area.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority of U.S. patent application Ser. No. 61/534,615 filed Sep. 14, 2011, which is hereby incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to cargo systems, and more particularly, to a universal load device fire suppression system. 
         [0003]    Millions of dollars of aircraft and property have been lost to cargo fires developing during transportation, especially in a load device, such as a universal load device (ULD). Aircraft cargo may typically be remote from the pilot or other aircraft personnel. Consequently, there is a delay in personnel knowing of a fire in the cargo hold and a delay in being able to put the fire out. In some cases, cargo aircraft have not been able to react soon enough to get back on the ground during in-flight fires. 
         [0004]    As can be seen, there is a need for a fire suppression system that may recognize a fire and maintain the fire within a ULD for suppression. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a perspective side view of a cargo container according to an exemplary embodiment of the present invention; 
           [0006]      FIG. 2  is a perspective top view of a base wall of the cargo container of  FIG. 1 ; 
           [0007]      FIG. 2A  is a cross-sectional side view of a liner used in a wall of the cargo container of  FIG. 1 ; 
           [0008]      FIG. 3  is a top view of base wall of  FIG. 2  sans the liner; 
           [0009]      FIG. 4  is a side exploded view of a fire suppression system that may be used in the cargo container of  FIG. 1  according to another exemplary embodiment of the present invention; 
           [0010]      FIG. 5  is a side view of the fire suppression system of  FIG. 4 , mounted; 
           [0011]      FIG. 6  is an internal front view of a control box of the fire suppression system of  FIG. 4 ; 
           [0012]      FIG. 7  is a side view of the control box of  FIG. 6 ; 
           [0013]      FIG. 8  is an exploded view of a sensor and control box of the fire suppression system of  FIG. 5  without a fire suppression cylinder; 
           [0014]      FIG. 9  is an internal rear view of the control box of  FIG. 6  with an integrated battery; 
           [0015]      FIG. 10  is a right side view of the control box of  FIG. 7 ; and 
           [0016]      FIG. 11  is a schematic diagram of an electrical circuit employed in the fire suppression system of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0018]    Broadly, an exemplary embodiment of the present invention generally provides a fire detection and suppression system. An exemplary embodiment of the present invention provides an automatic fire detection and suppression system designed for a cargo craft to protect from a fire spreading amongst cargo containers. Another embodiment may include a liner designed to fireproof cargo containers so that if a fire occurs within a container, elements outside the container are protected. Also, if a fire occurs outside the container, the contents of the container may be protected from the exterior. 
         [0019]    Referring now to  FIG. 1 , a cargo container  8  is shown according to an exemplary embodiment of the present invention. The cargo container  8  may be for example, a universal load device (ULD). The cargo container  8  may include, for example, steel walls and framing. The cargo container  8  may include a fire extinguisher  304  mounted inside a recessed mounting cabinet  305 . In some embodiments, the extinguisher  304  may be protected behind a door of the cabinet  305 . The cargo container  8  may include a roll-up type stainless steel door  303  allowing easy access to the interior. The cargo container  8  may also include a check valve  302  to relieve at least some pressure from within the cargo container  8 , which may maintain a positive fire extinguishant environment. The check valve  302  may allow suppression gases to stay within while atmospheric gases are expelled. While the check valve  302  is shown on a roof of the cargo container  8 , it will be understood that the check valve  302  may be placed on any of the walls. 
         [0020]    Referring now to  FIGS. 2 ,  2 A, and  3 , various views of the interior lining of the cargo container  8  ( FIG. 1 ) are shown. A liner  10  may be configured to resist fire and prevent fire from penetrating through the liner either from within the cargo container  8  or from the exterior of the cargo container  8 . The liner  10  may include a heat resistant sheet of metal  5  positioned between two sheets of copper  6 . The heat resistant sheet of metal  5  may be a metal with a melting point approximately above 1700°. In some embodiments, the liner  10  may be configured to resist or contain a class “D” fire. The heat resistant sheet of metal  5  may be thick enough to prevent fire from penetrating through the heat resistant sheet of metal  5 . The heat resistant sheet of metal  5  may include for example tungsten. In some embodiments, the heat resistant sheet of metal  5  is entirely tungsten. The liner  10  may be disposed against an interior wall of the cargo container  8 . For example, the liner  10  may be positioned over a base  7 . The base  7  may be an aluminum pallet. 
         [0021]    Thus, for example, when combustion occurs within the cargo container  8 , fire may encounter the liner  10  before reaching any of the cargo container  8  walls. Fire may in some cases penetrate through the copper sheet  6  however the sheet of tungsten  5  may then contain the fire. It will be appreciated however, that by covering the sheet of tungsten  5  with copper, the tungsten may be protected from environmental contamination and degradation. For sake of illustration, the liner  10  is shown on the base  7  however it will be understood that the liner  10  may line any interior wall. 
         [0022]    Referring now to  FIGS. 4-11 , a fire extinguisher  304  is shown along with an electrical schematic providing detail of electronic connections according to an exemplary embodiment of the present invention. The fire extinguisher  304  may include automatic fire detection and suppression functions. 
         [0023]    The fire extinguisher  304  may include an electronic control box  1 , which may house all electrical circuits and batteries. A fire detector  27  (sometimes referred to as the detector  27 ) may be coupled to the control box  1 . In some embodiments, the detector  27  is a smoke detector or a heat detector. Control and activation of the detector  27  may be controlled by the control box  1 . Detection of a fire by the detector  27  may activate release of a fire extinguishant. An electric actuator  12  may be used to electrically open and close a valve assembly  110  that releases the fire extinguishant housed within a cylinder  2 . A chafe strip  31  may be added to the control box  1  to prevent chafing and keep the control box  1  in place with the cylinder  2 . A personal computer board  15  inside the control box  1 , such as a circuit controller with associated wiring, may be used to mount electrical control devices. 
         [0024]    The cylinder  2  may be a pressure vessel installed to store fire extinguishant under pressure until ready for release. A cylinder mount  28  may be a mounting assembly to hold the pressure cylinder in place. A pressure gauge  106  may indicate amount of pressure inside the cylinder  2 . A valve assembly adapter  107  may be screwed into a valve assembly  110  to allow a spray nozzle  108  to be attached. 
         [0025]    The spray nozzle  108  may be attached to a valve assembly adapter  107  that atomizes the fire extinguishant upon release. A base coupler  109  may attach the actuator base  111  to the pressure cylinder neck adapter. An actuator base  111  may be a mounting bracket for the electric actuator  12 . An actuator coupler  113  may transfer motion from the electric actuator  12  to the valve assembly  110 . 
         [0026]    An attaching hardware  114 , such as a bolt, screw, washer, for example, may be attached to the actuator base  111 . A spray deflector  115  may spread out and help atomize and disperse fluid flowing out of a heat fuse. A threaded pipe elbow  116  may be used for spray nozzle plumbing. A threaded pipe coupler may be used for spray nozzle plumbing. 
         [0027]    A pipe threaded adapter  118  may be included for spray nozzle plumbing. A pressure cylinder neck coupler  120  may be attached to the pressure cylinder neck and the electric actuator base. The pressure cylinder neck adapter  121  may thread into pressure cylinder neck and become an extension of the neck, providing area for heat fuse  122  and the pressure gauge. The heat fuse  122  may be a melting fuse that allows the fire extinguishant to be released under certain atmospheric temperatures. 
         [0028]    A main system battery tray  16  may be used to mount batteries  17  inside the control box  1 . A detector power switch  18 , such as an on/off power switch, may be installed for the detector  27 . A fire suppression power switch  19 , such as an on/off switch, may be used to engage the fire suppression extinguishant release. A reverse polarity switch  20  may have three position switches, for example, to reverse voltage from latching relay to reset system. The detector  27  may sense a fire and may start a relay effect that opens the pressure cylinder  2  while providing an alert to people, such as aircrew via a transmitter  201 . A fire suppression discharge light  29  may alert ground crews that the discharge of the extinguishant has occurred. An actuator reverse switch  30  may allow the actuator  12  to reverse and be placed back into an armed position. 
         [0029]    A voltmeter  21  may be used to monitor system voltage of the detector  27  and electronic control system. A voltage test switch  22  may apply power to the voltmeter  21  for monitoring system voltage. A rubber battery insulation pad  24  may be used to insulate a battery  17 . Strap retention slots  25  may be formed in the control box  1  for holding strap  26  that may retain the pressure cylinder  2 . 
         [0030]    A diode  32  may be placed into electrical circuit to remove AC current. A detector battery  100  may supply main power to detector  27 . A voltage regulator  101  may be installed to provide proper voltage for voltmeter  21 . A fuse  102  may be installed to provide proper voltage for light emitting diode (LED) light. Latching relay  104  may be installed to operate as power relay for the electric actuator, triggered by the detector  27 . 
         [0031]    Some of the electrical components may be mounted on the PC board  15 , which in turn may be mounted in the electronic control box  1 . The detector  27  may be powered by the detector battery  100 , through the detector power switch  18 . The detector  27  may sense the smoke or heat which sends a DC voltage signal to a latching relay  104  through a reverse polarity switch  20  and diode  32 . The reverse polarity switch  20  may be used to reverse the polarity of the battery to reset the latching relay  104 . 
         [0032]    Once the latching relay  104  detects the voltage from the detector  27 , the latching relay  104  may latch and close the circuits from the main system batteries  17  through the fire suppression power switch  19 , the fuse  102 , the fuse holder  105 , and power the electric actuator  12  open. The actuator reverse switch  30  may be installed to switch the electric actuator  12  to a closed position. 
         [0033]    To make sure all circuits are powered properly, a battery test function may be developed. This may consist of a voltmeter  21 , powered by a voltage regulator  101 . The voltage regulator  101  may receive an electrical signal from main system batteries  17  through a voltage test switch  22  and push to test switch  23  to selectively test each battery voltage. 
         [0034]    The main system batteries  17  may be mounted in the control box  1  with two main system battery trays  16  with an attaching hardware  14 . The lower main system battery  17  may be protected from accidental shorting by a rubber battery insulation pad  24  under the upper battery-mounting tray  16 . The electronic control box  1  may be mounted to the pressure cylinder  2  through strap retention slots  25  with control box retaining straps  26  and the chafe strips  31  between the electronic control box  1  and the pressure cylinder  2 . 
         [0035]    A fuse holder  105  may be installed to mount the fuse  102  into the electric circuit. A transmitter power switch  200  may be installed to control the on/off power for a transmitter  201 . The transmitter  201  may be installed to send signal to the receiver  205  to alert the user of possible fire hazard and the extinguishant has been released. 
         [0036]    A transmitter battery  202  may be the main power source for the transmitter  201 . A latching relay  203  may be associated with the transmitter  201  that closes the circuit on the transmitter  201  to send a warning signal, which is triggered by the detector  27 . A push to test switch  210  may allow an operator to test the transmitter  201  without triggering the latching relay  203 . 
         [0037]    A receiver battery  204  may be the main power source for receiver  205 . The receiver  205  may be installed, for example, in a cockpit, to receive a warning signal from the transmitter  201 . The receiver  205  may have a light and buzzer warning for the user alerting the user of an overheat and/or smoke condition existing in the cargo area. The receiver buzzer  206  may alert users to the possibility of a fire hazard. 
         [0038]    The receiver LED  207  may be installed to alert a user to a possible fire hazard. The receiver resistor  208  may be added to the LED circuit to create a proper voltage. A receiver power switch  209  may be installed to control the on/off power for the receiver. A receiver arm or disarm switch  211  may be installed in the LED or buzzer circuit to disarm or shut off the fire hazard warning. 
         [0039]    The transmitter  201  may be powered by the detector battery  202  through the transmitter power switch  200 . When triggered, the latching relay  203  may close and cause the detector input circuit to send signal to the receiver  205 . The receiver  205  may be powered by the receiver battery  204  through the receiver power switch  209 . When triggered, the receiver  205  may produce an electrical current that energizes the receiver buzzer  206  and the receiver LED  207  through the receiver resistor  208  and the receiver arm or disarm switch  211 . The trigger power source for the entire 24 volt mechanical system may be a replaceable 9 volt battery, which may keep this system in a state of low maintenance and high reliability. 
         [0040]    When smoke or heat is introduced to the detector  27 , this may trigger an electrical signal which may be sent to two latching relays. The first latching relay may close a circuit that allows the electric actuator to open the valve assembly  110  and release the fire extinguishant. The second latching relay may close a circuit that allows the transmitter  201  to transmit a signal to the receiver  205  which illuminates a light and sounds a buzzer. If the detector  27  is attached to a computer, the computer may control the electric actuator to release the fire extinguishant and send the signal to the receiver  205  via the transmitter  201 . 
         [0041]    An exemplary embodiment of the present invention may be used to suppress airborne fires, for example, in modified ULDs. Once the ULDs are modified according to an exemplary embodiment of the present invention, a fire extinguisher  304  may be mounted inside the ULD and turned on and armed. The detector  27  and the receiver  205  may be turned on and armed. The early-warning transmitter  201  and receiver  205  may let, for example, a pilot know as soon as a fire erupts and may provide valuable time to get the aircraft on the ground to prevent in-flight catastrophe. 
         [0042]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. For example, while the foregoing has been described in the context of protecting cargo, embodiments of the present invention may be placed inside storage rooms to protect property and homes during natural disaster, such as forest fires.