Abstract:
Sound producing apparatus ( 20 ) is disclosed which simulates a fire cracker. The apparatus comprises a selectively actuatable aerosol ( 24 ) which fills a chamber ( 35 ) with compressed fluid which, when a certain pressure is reached, blows off a cap ( 38 ) creating a shower of confetti ( 39 ) and a loud bang. In other embodiments, a plurality of elastomeric members filled with compressed air which are ruptured or a selectively operable compressed fluid container formed by the apparatus housing, art used to create a similar effect.

Description:
FIELD OF THE INVENTION 
     This invention relates to sound producing apparatus more particularly, but not exclusively, to fireworks and fire crackers. 
     BACKGROUND OF THE INVENTION 
     Fireworks and, in Chinese culture, fire crackers form an integral part of many celebrations, such as at Chinese New Year, opening ceremonies and birthdays. In recent years, however, the use of fireworks and fire crackers has been restricted and in some countries such as Hong Kong and Singapore such use is forbidden, due to the inherent safety hazards of such products. 
     It is the object of the invention to provide a sound producing apparatus which alleviates this disadvantage of conventional fireworks and fire crackers. 
     SUMMARY OF THE INVENTION 
     According to the invention, there is provided sound producing apparatus comprising a container arranged to contain compressed fluid; and a chamber in selective fluid communication with the container, the chamber having an outlet arranged to open when fluid pressure in the chamber exceeds a threshold. 
     The apparatus preferably further comprising a housing which either forms or contains the container and/or the chamber. 
     The container may be a pressure pack dispenser or an aerosol having an outlet valve and may further comprise a housing in which the container is movable between a first position in which the valve is opened and a second position in which the valve is closed and a stop member which engages and opens the valve in the first position. 
     The container may be formed from an elastomeric material and the apparatus preferably further comprises a rupture member for rupturing the container, the rupture member preferably being a pin member or a piston member. At least one further container may be provided, the containers being openable one after the other. 
     The container and chamber are preferably connected by at least one selectively operable valve means which may comprise (1) a valve member slidable in a valve sleeve, the valve member and sleeve having openings which in an open position align to allow fluid transfer through the valve or (2) a valve member slidable between open and closed positions relative to a sealing element, the valve member having a fluid passageway which in the open position allows fluid transfer past the sealing element and/or (3) a sleeve of elastomeric material covering a fluid transfer opening, the sleeve forming a one-way valve member. 
     The apparatus further preferably comprises means for controlling opening of the container and the controlling means may comprise a control fluid inlet for receiving a fluid control signal for opening the container or may comprise means for receiving an electrical control signal for opening the container. 
     The apparatus preferably farther comprises a sealing member covering the outlet, the sealing member being displaceable when the fluid pressure exceeds the threshold. 
     The sound producing apparatus is preferably in the exterior form of a fire cracker (or other explosive device) and confetti and/or a powdered material is/are preferably disposed in the chamber. 
     The compressed fluid may be gaseous such as air or liquid such as liquid petroleum gas or liquid propellant. 
     The invention extends to a plurality of sound producing apparatuses which may be connected together to resemble a string of fire crackers. 
     One sound producing apparatus is preferably associated with a delay means for delaying actuation of another sound producing apparatus. 
     The delay means may comprise a valve includes a valve member resiliently biased towards a valve seat, the valve being openable in response to increased pressure against the valve member to force the valve member away from the valve seat or a rupture disc. 
     A source of compressed fluid is preferably connected to the sound producing apparatuses and a resilient elastomeric member may further be provided, the resilient elastomeric member being inflatable to beyond the point of rupture in response to introduction of fluid from said fluid source. 
     The delay means may comprise an electrical delay circuit. 
     In the described embodiments of the invention, a housing of the sound producing apparatus is in the exterior form of a fire cracker, the outlet being covered by a displaceable cap and a region adjacent the cap being filled with confetti and a fine powder, so that when the cap is displaced, a loud bang is heard as the fluid under pressure escapes and, at the same time, a shower of confetti and the powder, which simulates smoke, is expelled. The apparatus thus simulates a fire cracker without the associated dangers. 
     A plurality of sound producing apparatuses may be connected together to resemble the tree-like formation of a typical fire cracker. Each sound producing apparatus is connected to the next and actuated via a respective delay means so that one sound producing apparatus is actuated before the next and so on, to give a staggered series of bangs like a conventional fire cracker tree. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a part-sectional view of a simulated fire cracker tree incorporating an embodiment of sound producing apparatus of the invention; 
     FIG. 2 is a cross-sectional view, on an enlarged scale, of the sound producing apparatus shown in FIG.  1 . 
     FIG. 3 is an enlarged cross-sectional view of a connector for connecting the sound producing apparatus to a fluid actuator source in the fire cracker tree of FIG.  1 . 
     FIG. 4 is a cross-sectional view, similar to FIG. 2 of a second embodiment of the invention. 
     FIG. 5 is a cross-sectional view, similar to FIG. 2, of a third embodiment of the invention. 
     FIG. 6 is a view similar to FIG. 1 illustrating an alternative connector. 
     FIG. 7 is an enlarged sectional view of the connector shown in FIG. 6 
     FIG. 8 is a cross-sectional view, similar to FIG. 2, of a fourth embodiment of the invention. 
     FIG. 9 is a cross-sectional view, similar to FIG. 2, of a fifth embodiment of the invention. 
     FIG. 10 is a cross-sectional view of the embodiment of FIG. 9 once actuated. 
     FIG. 11 is a cross-sectional view, similar to FIG. 2, of a sixth embodiment of the invention. 
     FIG. 12 is a cross-sectional view of the sixth embodiment, once actuated. 
     FIG. 13 is a cross-sectional view similar to FIG. 7 illustrating a second alternative connector; and 
     FIG. 14 is a cross-sectional view across  14 — 14  of FIG.  13 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIG. 1, a simulated fire cracker “tree” generally designated  10  is shown. The simulated fire cracker tree is shaped, externally, to resemble the conventional one in which a plurality of fire crackers are connected together by a fuse, terminating in a single, larger “finale” cracker. In use, the fuse is lit and the fire crackers are exploded one after the other with the largest, loudest cracker being saved until last. 
     In the embodiment of the present invention now described, the conventional fire crackers are each replaced by a sound producing apparatus simply referred to hereafter as an “air cracker”  20 . The air crackers  20  are connected together by tubes  40  via connectors  50 . The first tube  40  is connected, at one end, to a source of compressed fluid (such as compressed air or liquid propellant)  44  via a valve  42 . The last tube  40  is connected to a balloon  70  filled with confetti  72  via a throttle  74  to reduce airflow, the balloon  70  being enclosed in a paper housing  76 . An ornamental scroll  77  is held in place by the housing  76 . 
     The air cracker  20  is shown in more detail in FIG.  2  and comprises a hollow cylindrical housing  22  preferably formed from red plastics material in which a pressure pack dispenser or aerosol  24  containing a compressed fluid, preferably compressed air, is disposed. The dispenser is a snug but sliding fit in the housing  22  and an O-ring  26  forms a fluid seal between the housing  22  and aerosol  24 . The dispenser is provided, at one end, with a depression-openable valve  28  and a fluid outlet  30 . The valve is of a conventional construction so that upon depression of outlet  30 , fluid under pressure can escape from aerosol  24 . A cylindrical stopper  31  is held in housing  22  and receives the free end of outlet  30  in a cylindrical recess  32  which is in fluid communication with a cylindrical fluid outlet  34 . 
     The housing  22  is provided, at one end, with a hollow cylindrical projection  37  forming a control fluid inlet  36 . The dispenser is provided with a circular recess  25  at its base, in fluid communication with inlet  36 . The housing at the other end is provided with a chamber  35  having displaceable sealing member or cap  38  formed, for example, from plastics material, cardboard or paper, the chamber  35  being filled with confetti  39 . 
     The air cracker  20  is attached to connector  50  shown in FIG.  3 . Connector  50  has a valve body  69  with three cylindrical bores  51 ,  52 ,  53  formed therein. Cylindrical protrusion  37  of air cracker  20  is held in bore  53  and two tubes  40  are held in cylindrical bores  51 ,  52 , by any convenient means. Bores  51 - 53  are in fluid communication via conduits  54 ,  55 ,  56 . Conduits  54  and  55  which connect bore  51  which is connected to tube  40  closest to air supply  44  and bore  53  which is connected to air cracker  20 , are in direct fluid communication. Conduit  55  is, however, connected to conduit  56  via a valve  60 . Valve  60  comprises valve member  62  of conical form engaging a cylindrical knife edged valve seat  64 . Valve member  62  is held in contact with valve seat  64  by means of a spring  66  held in place by means of a cap  68  which threadedly engages valve body  69 . 
     In use, the air crackers  20  are assembled into a tree as shown in FIG.  1 . When a user desires to actuate the air crackers  20 , valve  42  is opened allowing air under pressure to pass from reservoir  44  along tube  40 . When the first connector  50  is reached, the air under pressure, through conduits  54 ,  55  enters control fluid inlet  36 . The resulting increased pressure acts on the recess  25  of aerosol  24  causing the aerosol to move to the right in FIG. 2 against stopper  31 , this causing fluid outlet  30  to be depressed relative to valve  28 . Compressed air then rushes out of the aerosol  24  through outlet  34  quickly raising the pressure in chamber  35  adjacent displaceable cap  38  until the cap either ruptures or blows off the housing  22 . At that point, due to the high pressure difference, a sudden pressure wave will be generated causing a loud bang, at the same time blowing the confetti  39  out of the air cracker  20 , thus simulating the explosion of a fire cracker. 
     All air crackers  20  operate in the same way but, due to the operation of vales  50 , do so one after the other in the manner of a conventional fire cracker tree. More specifically, with reference to FIG. 3, after valve  42  has been opened, conduits  54  and  55  will rise in pressure; as the pressure rises this will cause valve  60  to open by forcing valve member  62  back against spring  66  and away from valve seat  64 , thus allowing compressed air from reservoir  44  to flow through conduit  55  to conduit  56  and thus to the next connector  50 , so to actuate the next air cracker  20 , and so on with a short time delay, dependent on the speed at which valve  60  opens, occurring between actuation of each air cracker .  20   
     After the last air cracker  20  has been actuated and the corresponding valve has opened, the compressed air from reservoir  44  flows via throttle  74  into balloon  72  which expands. The balloon ruptures paper casing  76 , causing the scroll  77  to unroll and continues to expand until bursting, the confetti  72  in the balloon then being expelled as a shower. 
     A second embodiment of the air cracker is shown in FIG. 4 in which housing  100  is similar to housing  22  of FIG. 2 but contains three spherical elastomeric containers  112 ,  114 ,  116 , for example small inflated balloons, containing compressed air. At one end of container  100 , a hollow cylindrical projection  102  connects to connector  50  in the same manner as the embodiment of FIG.  2 . Bore  104 , however, contains a captured pin  106 , of any conventional construction, which is resiliently biased within passage  104  but able to move into housing  100  and rupture container  112  in the same manner as applying a needle to a balloon, once pressure from reservoir  44  is received via connector  50 . The substantially increased pressure within housing  100  when container  112  is ruptured will cause a knock-on effect, rupturing container  114  which in turn ruptures container  116 . Confetti  120  is disposed in a chamber  121  between container  116  and opening  108  of housing  100 . A cap  122  is placed over opening  108 . When use, the rupturing of containers  112 ,  114 ,  116  will cause a blast of air to rupture or blow off cap  122 , at the same time generating a staggered series of loud bangs and producing a shower of confetti. 
     A third embodiment of the air cracker invention is shown in FIG. 5 which is similar to the embodiment of FIG. 4 except that (1) needle  106  is replaced by a cylindrical piston member  130  which is provided with a sealing O-ring  132  and (2) a stopper member  134  is securely connected to casing  100 . In use, increased pressure in passageway  104  causes piston member  130  to compress containers  112 ,  114 ,  116  causing them to rupture. In order to assist this process, stopper member  134  may be provided with a plurality of prongs  136 , to rupture container  116 . The compressed air thus released then exits through openings  135 , the air cracker operating as described with reference to FIG.  5 . 
     A variation of the connector  50  is shown in FIGS. 6 and 7. In these figures, the air cracker tree is the same as that of FIG. 1, the only difference being connector  150 . 
     As shown in more detail in FIG. 7, connector  150  has four connecting bores  152 ,  154 ,  156 ,  158 . Bore  152  is connected to tube  40  and is nearest to compressed air source  44 . Bores  154 ,  156  are connected to respective air crackers  20  and are in direct fluid communication with bore  152  via passageways  160 ,  162 ,  164 . Bore  158  is connected to downstream air crackers via a rupture disc  170  and tube  40 , the bursting of the rupture disc  170  due to increased pressure of a predetermined level causing a delay in the similar manner to valve  60  of FIG.  3 . 
     FIG. 8 shows a fourth embodiment of the invention which is the same as FIG. 2 except that the O-ring  26  has been replaced by a cylindrical rubber piston member  29 . The operation of the embodiment of FIG. 8 is the same as that of FIG. 2 except that when air under pressure enters through control inlet  36 , this acts on piston member  29  to force piston member  29  against aerosol  24  and move with it as valve  28  opens. 
     A fifth embodiment of invention is illustrated in FIGS. 9 and 10. In this embodiment, part of the air cracker housing forms the container of the previous embodiments. Specifically, hollow cylindrical housing  300  is provided with two spaced cylindrical elements  310 ,  320 , each having a co-axial bore  311 ,  321 . Element  310  is secured to and forms an end of housing  300 . Element  320  includes a cylindrical base portion  322  which rests on a shelf  323  of housing  300 . Portion  322  is held adjacent the shelf by a circlip  324 . 
     A valve member  330  is disposed between the elements. A central portion  332  of member  330  is connector to narrower end portions  334  and  336  which are slidable in the respective bores  311 ,  321 . Ridges formed between the narrower portions  334 ,  336  and central portion  332  limit the degree of sliding travel of the member  330  which can move from a closed position shown in FIG. 9 to an open shown in FIG.  10 . Bore  311  is connected at one end to a bore  342  formed in a projection  346  to provide a control fluid inlet in the same manner as previous embodiments. End portion  334  is provided with a sealing O-ring  339  which sits in a corresponding annular recess to prevent fluid leakage along bore  311 . 
     A generally hollow cylindrical chamber  350  is formed between housing  300  and member  330  and the chamber  350  is arranged to be filled with compressed fluid in the manner of the previous embodiments. End portion  336  and element  320  together provide a valving means to enable the space  350  to be filled with compressed fluid and for compressed fluid to be discharged therefrom. For filling, end portion  336  is provided with a hollow cylindrical bore  352  which connects, at one end, to a pair of radially extending bores  354 ,  356 . The free ends of bores  354 ,  356  lie in an annular channel  358  in which a sleeve  360  formed from rubber or other elastomeric material is disposed. Free end  362  of bore  352  is connectable to a source of compressed air (or other compressible fluid). In use, sleeve  360  acts as a one way valve so that compressed air from opening  362  will enter space  350  via bores  352 ,  354 ,  356 , pushing open sleeve  360 . The compressed air in space  350  will, after filling, force sleeve  360  into contact with the openings of bores  354 ,  356 , thus sealing a connection and preventing the compressed air from being expelled. 
     Valving to allow air to be expelled from space  350  is provided by two radial bores  370 ,  372  formed in element  320  and a further pair of radial bores  374 ,  376  formed in end portion  336  which are connected at one end to an annular channel  378  and at the other to bore  352 . O-rings  380 ,  382  and  384  prevent leakage of compressed fluid along bore  321 . 
     End  362  of bore  352  projects into a chamber  390  filled with confetti. A sealing member or cap  392  of the same design as the previous embodiments covers the chamber  390 . 
     In use, the space  350  is filled with compressed air and the chamber  390  packed with confetti and sealed with cap  392 . When it is desired to actuate the air cracker, compressed air is applied through bore  342  to move member  330  from the position shown in FIG. 9 to that shown in FIG. 10 at which bores  370 ,  372  align with bores  374 ,  376  and annular recess  378 , causing air to be expelled from space  350  into chamber  390 . The pressure in chamber  390  builds up until cap  392  either ruptures or blows off causing a loud bang and the confetti to be expelled in the manner of the previous embodiments. 
     A seventh embodiment is shown in FIGS. 11 and 12. The seventh embodiment is substantially the same as the sixth embodiment except that element  400  is now in the form of a cylindrical sealing disk in the central bore  408  of which a cylindrical end portion  401  of member  330  is slidably received. Bores  370 - 376  of the embodiment of FIG. 6 have been replaced by two axial grooves  402 ,  404  in portion  401  which are of a length greater than the width of disk  400 . A sealing O-ring  406  is provided to prevent leakage of compressed air along the bore  408 . 
     As shown in FIG. 11, which shows the air cracker in a charged position, the slots  402 ,  404  do not communicate with chamber  390  and, any seepage of air is blocked by O-ring  406 . When actuated, shown in FIG. 12, the grooves  402 ,  404  connects space  350  with chamber  390 , thus allowing air to enter chamber  390  increasing the pressure in the chamber until the cap ruptures or blows off expelling the confetti as shown. 
     A third form of valve member similar to that shown in FIG. 6, is shown in FIGS. 13 and 14. A valve body  500  is provided with a compressed air inlet  510  and a compressed air outlet  520  to which are connected first  525  and second  524  connectors to which air crackers are respectively attached. Inlet  510  and outlet  520  are further connected by means of a valve  530 . This connection is shown in more detail in FIG.  14 . Inlet  510  is connected by means of a bore  512  to a valve chamber  532  in which a valve member  534  sits. The valve member  534  is biased by a spring  536  held in place by a cap  538  towards a valve seat  540 . The valve member  534  is a conical shape so that air pressure applied through bore  512  will tend to act against the bias of spring  536 , so that when the pressure is great enough, this will force up the valve member  534  to the point where bore  512  is in communication with a bore  525  connected to outlet  520 , so that the compressed air may be supplied to the air crackers connectors  522 ,  524 . The inertia of the valve provides a time delay for actuation of the air crackers through connectors  522 ,  524 , as before. 
     The confetti may be mixed with a fine powder to provide the impression of smoke. Preferably the powder is flour or talcum powder. 
     The embodiments of the invention described above are not to be construed as limitative. For example, actuation control of the air crackers has been effected in the described embodiments by fluid means. This could be achieved by any other suitable means, for example electrical (solenoid) operation with the delay valves being replaced by delay circuits. Furthermore, the air crackers need not be disposed as part of an air cracker tree, but may be used separately to represent a single firework, fire cracker, thunder flash or a simulated explosion device such as a mortar simulator. When forming part of a tree, some or all of the delay means may be omitted, depending on the effect desired.