Abstract:
A fireball generator device comprising a steel cylindrical main housing having first and second threaded end caps. A shotgun shell is encased in a barrel member and locked in place with a screw-on housing. When the shell is fired, the gases expelled by the shell push a knife blade forward into a gas container positioned within the main housing. The moving knife blade ruptures the gas container and the gas therein escapes and the powder gas from the shotgun shell ignites the gas escaping from the container creating various visual effects, such as a fireball.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    A reusable device for producing a safe and consistent sized gas fireball effect for various non-destructive device uses. 
         [0003]    2. Description of the Prior Art 
         [0004]    Devices for producing fireballs have been available in the prior art. The typical prior art device comprises black powder contained in a carboard cup, capped and wrapped tightly with tape and placed on a fuel source such as gasoline, in a non-metal container. 
         [0005]    The prior art fireball generators have at least one important limitation; once ignited, the device can not be reused. 
         [0006]    Co-pending application Ser. No. 11/199,861 of common inventorship discloses a reuseable special effects audible and visual fireball generator device which comprises a cylindrical main housing having end caps mounted at each end. A gas container is positioned within the housing and a knife blade is mounted within the housing adjacent one end cap. A holder containing a predetermined amount of black sporting powder is secured within the housing adjacent the other end cap. When the black sporting powder is ignited, the gas container is forced against the knife blade, rupturing the tank. The released liquid gas mixes with air and the black sporting powder igniting the mixture and providing a fireball effect. 
         [0007]    Although the device disclosed in the &#39;861 application performs very well, it would be desireable if a device could produce the same visual effects without the use of black powder and an electric ignitor. 
       SUMMARY OF THE INVENTION 
       [0008]    A fireball generator device comprising a steel cylindrical main housing having first and second threaded end caps. A shotgun shell is encased in a barrel member and locked in a place onto one of the end caps with a screw-on housing. When the shell is fired, the gases expelled by the shell push a knife blade member mounted adjacent the shell forward into a gas container positioned within the main housing. The moving knife blade ruptures the gas container and the gas therein escapes, the gases from the shotgun shell igniting the gas escaping from the gas container creating various visual effects, such as a fireball. 
         [0009]    To reuse, the user opens the second end cap, replaces the tank and then unscrews the barrel and replaces the shotgun shell and starts the process over again. The first and second end caps and cylindrical housing, both preferably fabricated from steel, are cold to the touch immediately after the fireball due to the liquid gas being expelled from the vented holder. Since the fireball lasts between 1 and 3 seconds, the steel end caps and cylindrical housing remain relatively cool and thus are not heat damaged, allowing these components to be reused. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0010]    For a better understanding of the present invention as well as other objects and further features thereof, reference is made to the following description which is to be read in conjunction with the accompanying drawing therein: 
           [0011]      FIG. 1  is a perspective view of the fireball generator device of the present invention; 
           [0012]      FIG. 2  is a plan view of the left end of the device shown in  FIG. 1 ; 
           [0013]      FIG. 3  is a plan view of the right end of the device shown in  FIG. 1 ; 
           [0014]      FIG. 4  is a cross-sectional view along line  4 - 4  of  FIG. 3 ; 
           [0015]      FIG. 5  is a cross-sectional view along line  5 - 5  of  FIG. 4 ; 
           [0016]      FIG. 6  is a front plan view of the knife blade taken along line  6 - 6  of  FIG. 4 ; 
           [0017]      FIG. 7  is similar to the view shown in  FIG. 4  showing the shot gun shell fired and the knife blade rupturing the gas cylinder; 
           [0018]      FIG. 8  is a cross-sectional view along line  8 - 8  of  FIG. 7 ; and 
           [0019]      FIG. 9  is a view along line  9 - 9  of  FIG. 7 . 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0020]    Referring now to the  FIG. 1 , the fireball generator device  10  of the present invention is illustrated. Fireball generator  10  comprises main housing cylinder  12 , preferably made of steel, and threaded end caps  14  and  16  also preferably made of steel. End cap  14  includes holes to enable electro-mechanical solenoid housing  18  to be mounted thereto. End caps  14  and  16  screw onto threads  19  formed on the ends of housing  12  as illustrated in  FIG. 4 . End caps  14  and  16  have a plurality of rib members  20  extending in a radial direction from the surface of the end caps, the rib members providing better gripping and turning features for a user and preventing device  10  from rolling around on the ground after device positioning. A plurality of venting holes  22  are formed around a portion of the circumference of housing cylinder  12 . As shown in  FIG. 4 , a liquid propane (LP) tank  24  (or a same sized tank having an equivalent ignitable type gas, such as MAPP gas) having liquid propane gas  27  therein is positioned with the hollow interior area  28  of housing  12 . Four guide screws  32  ( FIG. 5 ) equispaced around the circumference of housing  12  secure and align tank  24  in place within interior area  28 . 
         [0021]    Referring to  FIG. 4 , an electro-mechanical solenoid firing pin  40  is positioned within solenoid housing  18  as illustrated. Housing  18  has an elongated portion  42  having an internal thread  44  formed on its inner surface. A knife blade assembly  50  comprises replaceable knife blade  52 , piston rod  54 , shotgun flank shell  56  and shotgun shell barrel and piston rod cylinder  58 . The end of cylinder  58  opposite knife blade  52  has an external thread  60  which is threadly engageable with thread  44 . Knife blade  52  screws into piston rod  54  as illustrated. 
         [0022]    As noted hereinabove, elongated portion  42  of solenoid housing  18  screws into the barrel shotgun shell  56 , securing the shotgun shell and keeping firing pin  49  at the correct distance from the prima cap of shell  56 . When the solenoid is activated, firing pin  49  hits the prima cap. Is should be noted that the commercially available solenoid has been modified to the extent that the solenoid rod acts as the firing pin  49  for the shotgun shell  56 . The firing pin  49  is activated using a capacitor discharge electronic system which has sufficient voltage (typically larger than 200 VDC) to push firing pin  49  forward with sufficient force and speed to cause shotgun shell  56  to fire. A solenoid manufactured by McMaster-Carr, Atlanta, Ga., Model No. 70155K11, with the piston modified with a bull nose to function as firing pin  49  has been successfully utilized. 
         [0023]      FIG. 6  is a front view of the knife blade  52  and comprises four fin like members  70  which converge to a central area  72 . Knife blade  52  includes a threaded shaft portion  74  ( FIGS. 4 and 7 ) which, as noted above, screws into piston rod  56 . 
         [0024]      FIG. 7  is similar to  FIG. 4  and shows knife blade assembly  50  after firing pin  49  has been activated such that shotgun shell  56  has been fired. Rod  54  is then propelled forward which in turn forces knife blade  52  into side  78  of container  24 , rupturing the side and allowing liquid propane  27  contained therein to escape into interior  28  of housing  12  wherein it turns into a gas  80 . Gas  80  fills the entire interior of housing  12  and mixes with the powder gas escaping from ports  47  formed in cylinder  58 , the resultant gas mix igniting and forming a fireball. 
         [0025]    The electro-mechanical solenoid pin  49  is activated using a high voltage pulse provided, for example, by a hand-held blasting machine used for igniting electric blasting caps. 
         [0026]    Starting with the housing cylinder  12  and end caps  14  and  16 , in order to fabricate the fireball generator of the present invention, a user unscrews the steel pipe main housing end cap  16  and then inserts tank  24  into the main housing  12 . Tank  24  is positioned such that threaded boss  37  on the end of tank  24  screws into the threaded well  41  formed on the interior surface of end cap  16  to secure the tank in place. Device  10  is then moved to a predetermined area and when all conditions are safe, the shotgun shell  56  is fired by an electro-mechanical solenoid firing pin. As noted hereinabove, the electro-mechanical firing pin  49  is activated using a high voltage pulse similar to a heart defibrillator or a hand-held blasting machine used for igniting electric blasting caps. 
         [0027]    The solenoid is screwed into a protective housing, the housing in turn screwing into the knife-blade assembly locking the shotgun shell in place. When the solenoid is energized, the firing pin  49  is quickly pushed forward into the shotgun shell  56 , similar to the mechanical firing pin of a gun. To reload gas container  24  and shotgun shell  56 , the housing  18  is screwed off the knife blade assembly  50  to expose the shotgun shell. End cap  14  is unscrewed to replace the gas container  24 . 
         [0028]    As an alterative to shotgun blank shell  56 , a mechanical device such as a hydraulic or air cylinder, or straight compressed gas or air, can be used to drive the knife piston/rod assembly into container  24 . In this case, an ignition source, such as a sparking device, is required to ignite the gas when container  24  is ruptured. 
         [0029]    The device of the present invention is not designed to be a weapon or destructive device and thus provides a simplified and economical device for generating an audible and visual fireball effect that provides a safe, consistent and predictable sized fireball effect for use within the entertainment industry and as a training aid for law enforcement, fire departments and other governmental agencies, the military and companies engaged in the business of security training. 
         [0030]    While the invention has been described with reference to its preferred 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 true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its essential teachings.