Patent Abstract:
A toy gun includes a body, a piston adapted to move relative to the body between an extended position and a retracted position and to be moved rapidly toward the retracted position during a firing stroke. A number of firing chambers each receive a projectile and air compressed by the piston during a firing stroke to fire the projectile from the toy gun. An air delivery mechanism conveys the compressed air to one of the firing chambers and co-operates with the piston to advance as a result of piston movement to a configuration whereat it can convey compressed air to another of the chambers.

Full Description:
BACKGROUND 
       [0001]    The present disclosure relates to multi-projectile toy guns. The disclosure more particularly, although not exclusively, relates to toy guns in which air is used to propel a succession of soft projectiles. 
         [0002]    It is known to propel soft projectiles from toy guns using air as the propellant. In some toy guns, air is rapidly compressed behind a projectile to force the projectile to fire from the toy gun. For some toy guns, a method is required to prime the gun prior to pulling a trigger to cause firing. Priming might be by pump-action to load a piston against a compression spring for example. The trigger would release the piston so as to move rapidly forward—compressing air behind the projectile. In other toy guns, there is no separate priming action. Instead, two handles are provided for grasping by separate hands. One handle is fixed with respect to the body of the gun whereas the other is fixed with respect to a piston. The two handles are reciprocated toward and away from each other and during the forward stroke air is compressed behind the projectile to cause it to be ejected. 
         [0003]    In multi-projectile toy guns of the type described above, some means is required to present the projectiles in succession to the firing position. For example, a barrel, magazine or “ammunition chain” might be loaded with projectiles. After one projectile is fired, a cylinder or ammunition chain must be advanced one position. With a gravity-feed magazine extending above the firing position, the next projectile might simply fall into position, but some means of mechanically advancing projectiles in a side or bottom-mounted magazine would be required. 
         [0004]    Toy guns with projectile advancing mechanisms are disclosed in U.S. Pat. Nos. 5,186,156 and 5,680,853 but each of these has a complex mechanism to cause advancement of the projectiles during a cocking operation of the toy gun. Moreover, complex systems of levers, ratchets and pawls are designed to cause the advancing mechanism to function during a reverse stroke of a plunger and then some further means is required to maintain alignment of the parts during the firing stroke. This is unnecessarily complex and expensive to manufacture. 
       SUMMARY 
       [0005]    Briefly stated, there is disclosed herein a toy gun, comprising: 
         [0006]    a body; 
         [0007]    a piston adapted to move relative to the body between an extended position and a retracted position and to be moved rapidly toward the retracted position during a firing stroke; 
         [0008]    a plurality of firing chambers each adapted to receive a projectile and to receive air compressed by the piston during a said firing stroke to fire the projectile from the toy gun, and 
         [0009]    an air delivery mechanism adapted to convey the compressed air to one of the firing chambers and co-operating with the piston to advance as a result of piston movement to a configuration whereat it can convey compressed air to another of the chambers. 
         [0010]    Preferably, the toy gun further comprises a first handle extending from the body to be grasped by one hand and a second handle extending from the piston to be grasped by another hand. 
         [0011]    The toy gun can further comprise a trigger associated with the first handle for releasing the piston. 
         [0012]    Preferably, each firing chamber further comprises an ejection nozzle via which air compressed by the piston is delivered to a projectile during the firing stroke. 
         [0013]    Preferably, the toy gun further comprises a pressure chamber situated between the firing chambers and the piston and via which the compressed air is conveyed to the firing chambers. 
         [0014]    Preferably, said plurality of said firing chambers is in a circular array. 
         [0015]    Preferably, the air delivery mechanism comprises a disc rotatable within the pressure chamber, the disc having a port aligned with one of the firing chambers, and means for rotatably indexing the disc to align the port with another one of the firing chambers. 
         [0016]    Preferably, the port has a check valve across it. 
         [0017]    Alternatively, the port can include a tube extending into the pressure chamber. 
         [0018]    Preferably, the toy gun further comprises a seal for sealing the port against each firing chamber. 
         [0019]    Preferably, the disc is adapted to move linearly within the pressure chamber. 
         [0020]    Preferably, said means for rotatably indexing the disc comprises a substantially cylindrical hub fixed with respect to the body and a ring attached to or formed integrally with the disc and surrounding the hub, the hub having an array of indexing fingers, the ring having one or more cams which engage upon linear movement of the disc with one or more of the fingers to rotate the disc. 
         [0021]    Preferably, the disc is biased by a spring toward the firing chambers. 
         [0022]    Alternatively, the air delivery mechanism comprises a conduit extending from the pressure chamber to one of the firing chambers, and means for rotatably advancing the conduit to align the conduit with another one of the firing chambers. 
         [0023]    The means for rotatably advancing the conduit can comprise a substantially cylindrical hub fixed with respect to the conduit and a cam attached to the piston, the hub having an array of indexing fingers, the cam engage upon movement of the piston with one or more of the indexing fingers to rotate the hub and conduit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    With reference to the drawings: 
           [0025]      FIGS. 1 ,  2  and  3  are schematic cross-sectional elevations of toy guns having different air delivery advancing mechanisms; 
           [0026]      FIGS. 4A to 9A  are schematic end elevations of a toy gun barrel having multiple firing chambers and soft projectiles located within some of the firing chambers. The number of and position of the projectiles corresponds figure-to-figure with  FIGS. 4B to 9B  alongside these figures respectively; 
           [0027]      FIGS. 4B to 9B  are schematic cross-sectional elevations of a toy gun showing a sequence of configurations of internal compartments during priming and firing of the toy gun; 
           [0028]      FIGS. 10 to 14  are schematic elevations of an air delivery advancing mechanism of the toy gun depicted in  FIGS. 4B to 9B ; 
           [0029]      FIG. 15  is a schematic perspective illustration of an advancing ring forming part of the advancing mechanism; 
           [0030]      FIG. 16A  is a schematic illustration of a check valve seal; 
           [0031]      FIG. 16B  is a schematic cross-sectional elevation of a portion of a disc having a check valve installed thereon and the seal of  FIG. 16A  in an open configuration; 
           [0032]      FIG. 16C  is a schematic cross-sectional elevation similar to  FIG. 16B , but showing the check valve seal in a closed configuration; 
           [0033]      FIG. 17A  is a schematic illustration of an alternative check valve seal; 
           [0034]      FIG. 17B  is a schematic cross-sectional elevation of a portion of a disc having a check valve installed thereon and the seal of  FIG. 17A  in an open configuration; 
           [0035]      FIG. 17C  is a schematic cross-sectional elevation similar to  FIG. 17B , but showing the check valve seal in a closed configuration; 
           [0036]      FIG. 18A  is a schematic illustration of another alternative check valve seal; 
           [0037]      FIG. 18B  is a schematic cross-sectional elevation of a portion of a disc having a check valve installed thereon and a floating plug in an open configuration away from the seal of  FIG. 18A ; and 
           [0038]      FIG. 18C  is a schematic cross-sectional elevation similar to  FIG. 18B , but showing the floating plug in a closed configuration pressed against to the seal. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0039]      FIGS. 1 to 3  of the accompanying drawings depict toy guns of similar construction, although each comprises a different means of indexing the delivery of compressed air from one firing chamber to the next. 
         [0040]    In  FIG. 1  there is depicted schematically a toy gun  10   a  including a body  11  and a cylinder  12  extending rearwardly from the body  11 . The cylinder  12  could alternatively be housed inside the body  11 . A piston  13  having an O-ring  15  slides linearly within the cylinder  12 . A stopper  32  prevents over-extension of the piston. The body  11  has a first handle  25  and the piston  13  has a second handle  14 . In use, the first handle is grasped by one hand and the second handle is grasped by the other. The handles are pumped in and out with respect to one another to fire projectiles in succession. 
         [0041]    At the forward end of the body  11 , there is provided a barrel  17 . The barrel  17  is fixed with respect to the body  11  and comprises a plurality of projectile chambers  24  in a circular evenly-spaced array. Within each chamber  24  there is provided a nozzle  37 . Individual soft projectiles  18  have hollow tail portions into which a nozzle  37  extends when the projectile is loaded within a firing chamber  24 . 
         [0042]    Located behind the barrel  17  is a cylindrical pressure chamber  16 . At the back of the pressure chamber  16  vent holes  22  are provided via which air can pass back and forth between the pressure chamber  16  in the area immediately forward of the piston  13 . 
         [0043]    The pressure chamber  16  communicates with each of the firing chambers  24 . Moreover, the nozzles  24  have air passages through them which extend to the pressure chamber  16 . 
         [0044]    Located within the pressure chamber  16  is a disc  19  which divides the pressure chamber into a pair of variable volume chambers. The disc  19  can move linearly within the pressure chamber  16  and can also rotate about its central axis. A guide pin  26  extends from the disc  19  and through an aperture in the rear wall of the pressure chamber and enables the disc to rotate as well as reciprocate. A disc return spring  23  surrounds the guide pin and serves to bias the disc  19  toward the barrel  17 . There is a small air gap  34  between the periphery of the disc  19  and the internal surface of the pressure chamber  16  to allow a small amount of air to pass around the periphery of the disc. There is also a vent  33  forward of the disc  19  through which air can pass from the general interior of body  11  to the pressure chamber  16  forward of the disc  19 . There is an airflow port  46  through the disc  19 . A check valve  21   a  is located upon the disc  19  across the airflow port  46 . The check valve is described in detail below with reference to  FIGS. 16A ,  16 B and  16 C. Aligned with and immediately in front of the check valve  21   a  is a seal  45  which surrounds the airflow port  46  and bears against the back of the barrel  17  when the disc  19  is in the fully forward position. Air passing through the airflow port  46  from the pressure chamber  16  via the check valve  21   a  therefore passes directly into nozzle  37  of one of the firing chambers  24 . 
         [0045]    The embodiment  10   b  of  FIG. 2  is the same as that of  FIG. 1 , except that instead of providing a check valve  21   a  across the airflow port  46 , an elongate tube  21   b  is provided which extends rearwardly of the disc  19  into the rear portion of the pressure chamber. The diameter and length of the tube is chosen to control air flow rate through the tube cause correct movement of the disc  19 . 
         [0046]    Fixed with respect to and extending from the back of the barrel  17  is an indexing hub  20 . The indexing hub  20  extends into a central recess of the disc  19  and co-operates with the disc to cause rotation of the disc between successive projectile firings. Pressure fluctuations caused by the piston  13  within the pressure chamber  16  cause the disc  19  to move back and forth along the axis of the guide pin  26 . The indexing hub  20  translates this linear movement of the disc into indexed rotation of the disc  19  to thereby sequentially align airflow port  46  with respective ones of the nozzles  37  between successive firings. The structure and operation of the indexing hub  20  will be described later with reference to  FIGS. 10 to 15 . 
         [0047]    The embodiment  10   c  of  FIG. 3  does not include a disc  19 , but instead provides a rotating conduit  30  rotatably sealed to the pressure chamber in front of the piston  13  by a seal  31 . The conduit has a radial segment at the forward end  21   c  at which an airflow port  46  is provided. Instead of the indexing hub  20  being affixed with respect to the back of the barrel  17  in this version, the indexing hub  20  is fixed about the axial portion of conduit  30 . A metal rod  27  is fixed to and extends from the piston  13  through a seal  28  and has at its forward end a cam  29  which engages with ramped fingers which are spaced around the indexing hub  20 . Upon retraction of handle  14 , the rod  27  draws the cam  29  backward to bear upon the ramped leading edges of one of the fingers to cause the hub  20  and conduit  30  to rotate in unison, thereby indexing the airflow port  46  with the next firing chamber  24 . 
         [0048]      FIGS. 4A to 9B  depict an embodiment of a toy gun  10   d  in which a trigger  36  is activated to release the energy of a piston spring  35 . In this embodiment, the handle  25  is grasped by one hand and the other hand is used to activate the priming handle  14 . Priming handle  14  is attached directly to the piston  13  to drawing back against the piston spring  35  whereupon a catch  38  retains the piston in a primed position. Activation of the trigger  36  releases the catch  38  so that the piston  13  moves rapidly forward to create projectile-firing pressure at the pressure chamber  16 . The forward portion of the toy gun  10   d  is for all intents and purposes the same as that of  FIG. 1  and these figures are intended to illustrate the operation of the disc  19  and the indexing mechanism. Reference will be made to  FIGS. 10 to 15  in the description to follow. 
         [0049]    In the rest position as depicted in  FIGS. 4A and 4B , the piston  13  is in the forward position and the barrel  17  has five of its six firing chambers  24  loaded with projectiles  18 . The barrel  17  can hold six projectiles although five are shown to indicate the loading state after the first projectile has been dispatched from the toy gun. Priming handle  14  is drawn backward as indicated by the arrow in  FIG. 5B  to commence compression of piston spring  35 . During this action, diminished air pressure behind in the disc  19  draws the disc backward and air is allowed into the forward portion of chamber  16  via vent  33  etc. Air also passes from the pressure chamber  16  through the vents  22  into the area immediately in front of piston  13 . 
         [0050]    After the priming handle  14  is released from the position depicted in  FIG. 6B  it is drawn forward by a spring as shown by the arrow in  FIG. 7B . Coincidentally, spring  23  biases disc  19  forward so that the seal  45  at port  46  seals the pressure chamber  16  with one of the nozzles  37 . The catch  38  retains the piston until the trigger  36  is activated as indicated in  FIG. 8B . The piston moves rapidly forward under the force of piston spring  35  and air rushes through the vents  22  and via the pressure chamber  16  and airflow port  46  into nozzle  37  causing projectile  18  to fire out of the toy gun. The piston comes to rest at the position depicted in  FIG. 9B . 
         [0051]    During the above procedure, the indexing mechanism is operative to rotate the disc  19  such that port  46  comes into alignment with successive firing chambers  24 .  FIGS. 10 to 14  illustrate the detail of the indexing mechanism. 
         [0052]    The indexing mechanism includes a cylindrical drum  20  which is affixed to or formed integrally with the back of barrel  17 . There is a spindle  47  over which the disc  19  can slide and rotate. This is not essential however. 
         [0053]    At the forward portion of the drum  20 , there is an array of fingers  41  each having a rear-facing ramp  42 . At the rear portion of the drum  20  there is another array of fingers  43  each having a forward-facing ramp  44 . The fingers are spaced peripherally about the drum  20  and are separated by grooves  48 . 
         [0054]    Surrounding the drum  20  is a ring  39 . The ring  39  is formed integrally with or attached to the disc  19  within the central recess of the disc  19 . The ring  39  is fixed with respect to the disc so as to rotate as one therewith. Formed on the internal surface of the ring  39  is a pair of diametrically opposed cams  40 . The cams  40  fit within the grooves  48 . To enable the drum  20  to be fitted into the ring  39 , two of the grooves open at  49  to the end of the drum. 
         [0055]    As noted earlier, pressure fluctuations within the pressure chamber  16  cause the disc  19  to reciprocate linearly. During this linear movement the cams  40  bear against the ramps  42  and  44 . Relative linear motion in either direction will thereby cause rotation of the ring in one direction only as indicated by the arrows in  FIGS. 11 and 13  thereby indexing the airflow port  46  as described. 
         [0056]      FIGS. 16A , B and C depict the check valve  21   a  in more detail. Attached to or formed integrally with the disc  19  behind the airflow port  46  and seal  45  is cylindrical body  50 . A circular cap  51  fits over the cylindrical body  50  and includes a port  55 . A flexible seal  52   a  is held in place against the end of the cylindrical body by the cap  51 . The flexible seal  52   a  has a number of apertures  53  in a circular array. The diameter of the circular array is larger than the diameter of the port  55  in the cap  51 . This allows the central portion of the flexible seal  52   a  to lift away from the port  55  to allow air to flow in the direction indicated by the arrow in  FIG. 16A , but the central portion presses against the port  55  to prevent air from flowing in the direction indicated by the arrow in  FIG. 16C . 
         [0057]    An alternative flexible seal  52   b  associated with a slightly different check valve  21   d  is shown in  FIGS. 17A , B and C. The seal  52   b  includes a central portion  56  partly surrounded by a C-shaped aperture  54 . The central portion  56  can hinge away from the port  55  as depicted in  FIG. 17B  to allow air to flow in the direction indicated by the arrow is in that figure. The central portion seals against the port  55  to prevent air from flowing in the direction indicated by the arrow in  FIG. 17C . 
         [0058]    A further option is depicted in  FIGS. 18A to 18C . In this embodiment the cylindrical body  50  of a variation of the check valve  21   e  has internal guide ribs  58 . A floating plug  57  resides within the cylindrical body  50  and can move longitudinally within it. The longitudinal airflow ribs  58  at the internal surface of the cylindrical body  50  enable air to flow around the plug  57 . The plug  57  moves away from the cap  51  to allow air to flow through the port  55  and around the plug  57  via the slots between ribs  58  as indicated by the arrows in  FIG. 18B . The plug  57  seals against the port  55  to prevent the back-flow of air in the direction indicated by the arrow in  FIG. 18C . 
         [0059]    It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention.

Technology Classification (CPC): 5