Abstract:
A projectile launcher for launching soft projectiles. The projectile launcher features a breech loading mechanism for loading soft projectiles into the launcher. The projectile launcher includes a pressure vessel which is pressurized by a positive displacement type pump which pumps ambient air into the pressure vessel. The butt stock is integrated to the piston of the pump so that the user may pressurize the pressure vessel by sliding the butt stock back and forth with respect to the pressure vessel. A specialized release valve is provided for optimum release of the pressure charge. Operating pressure for the launcher is limited by the pump design to prevent injury.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to the field of soft projectile launching toys. More specifically the present invention comprises a soft projectile launcher with a pressure vessel, an integrated pump for creating a pressure charge, and a specialized trigger-activated release valve for releasing the pressure charge and launching the soft projectile. 
         [0003]    2. Description of the Related Art 
         [0004]    Projectile launchers have long been known as novelty items. These launchers typically fire potatoes, vegetable slices, marshmallows, tennis balls, and the like. Some are spring loaded, while others use pistons to compress a charge of air. They typically fire a small projectile which can be used in “mock combat” games without actually injuring the target. These devices have also found application other than as novelty items. Some have been used to fire marking projectiles in the veterinary and timber industries. Others have been used as pill injectors for treating horses and cows. Thus, although such projectile launchers are most often viewed as novelty items, their applications may be much broader. 
         [0005]    Particularly, in mock combat situations it is desirable to limit the type of projectiles that may be “fired” from a projectile launcher to reduce the risk of injury. One particular concern in the field of novelty projectile launchers is the use of “improvised projectiles.” Users of the launcher often attempt to use the launchers to launch hard projectiles which could cause injury 
         [0006]    Accordingly, it would be beneficial to provide a projectile launcher which cannot be used to launch dangerous improvised projectiles and otherwise limits the risk of injury associated with the use of the projectile launcher. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present invention comprises a projectile launcher for launching soft projectiles. The projectile launcher features a breech loading mechanism for loading soft projectiles into the launcher. The projectile launcher includes a pressure vessel which is pressurized by a positive displacement type pump which pumps ambient air into the pressure vessel. The butt stock is integrated to the piston of the pump so that the user may pressurize the pressure vessel by sliding the butt stock back and forth with respect to the pressure vessel. A specialized release valve is provided for optimum release of the pressure charge. Operating pressure for the launcher is limited by the pump design to prevent injury. 
         [0008]    The preferred embodiment of the present invention includes a pressure vessel which is configured to contain a pressure charge of air and a pump which is fluidly connected to the pressure vessel. The preferred embodiment further includes a valve which is configured to contain the pressure charge in the pressure vessel when the valve is in the closed position, and release the pressure charge from the pressure vessel when said valve is in the open position. A bolt which is fluidly connected to the pressure vessel and is configured to receive the pressure charge when the pressure charge is released from the pressure vessel through the valve is also provided. A trigger which is operatively connected to the valve is configured to open the valve to the open position when pulled. 
         [0009]    In addition, a barrel may be attached around the bolt such that a portion of the barrel extends outwardly beyond the bolt. A loading chamber is formed within the region of the barrel that extends beyond the bolt. The loading chamber is configured to retain the soft projectile in position in front of the bolt until the user pulls the trigger and releases the pressure charge through the bolt. 
     
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view, showing the present invention 
           [0011]      FIG. 2  is an exploded view, showing components of the present invention. 
           [0012]      FIG. 3  is a perspective view, showing a pump assembly. 
           [0013]      FIG. 4  is a perspective view, showing components of the present invention. 
           [0014]      FIG. 5  is a perspective view, showing components of the present invention. 
           [0015]      FIG. 6  is a perspective view, illustrating the operation of the present invention. 
           [0016]      FIG. 7  is a section view, illustrating the operation of the present invention. 
       
    
    
     REFERENCE NUMERALS IN THE DRAWINGS 
       [0017]      
         [0000]    
       
         
               
               
               
               
             
           
               
                   
               
             
             
               
                 10 
                 projectile launcher 
                 12 
                 butt stock 
               
               
                 14 
                 vessel cap 
                 16 
                 pressure vessel 
               
               
                 18 
                 trigger grip 
                 20 
                 trigger 
               
               
                 22 
                 bolt 
                 24 
                 barrel grip 
               
               
                 26 
                 valve 
                 28 
                 neck 
               
               
                 30 
                 bolt pin 
                 32 
                 pin tab 
               
               
                 34 
                 cutout 
                 36 
                 valve body 
               
               
                 38 
                 cylinder 
                 40 
                 pump assembly 
               
               
                 42 
                 piston 
                 44 
                 spring 
               
               
                 46 
                 dome mating surface 
                 48 
                 valve disk 
               
               
                 50 
                 orifice 
                 52 
                 threaded neck 
               
               
                 54 
                 trigger 
                 56 
                 square sear 
               
               
                 58 
                 protrusion 
                 60 
                 pivot 
               
               
                 62 
                 brake 
                 64 
                 brake vents 
               
               
                 66 
                 bolt vents 
                 68 
                 barrel neck 
               
               
                 70 
                 barrel 
                 72 
                 action slot 
               
               
                 74 
                 loading chamber 
                 76 
                 loading port 
               
               
                 78 
                 rifled barrel 
                 80 
                 soft projectile 
               
               
                 82 
                 spacers 
                 84 
                 air passages 
               
               
                 86 
                 mating surface 
                 88 
                 groove 
               
               
                   
               
             
          
         
       
     
       DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The present invention is shown in its assembled state in  FIG. 1 . Projectile launcher  10  includes butt stock  12  which inserts through vessel cap  14  into pressure vessel  16 . Pressure vessel  16  is attached to bolt  22  so that the two components are fluidly connected, and trigger grip  18  is attached around the connection between pressure vessel  16  and bolt  22 . Trigger  20  is provided for releasing a pressure charge from pressure vessel  16  through bolt  22  as will be described subsequently. Connected to barrel grip  24  is the barrel of the projectile launcher. The barrel is attached around bolt  22  so that it can freely rotate around bolt  22 . Bolt pin  30  ( FIG. 2 ) is provided to restrict the movement of the barrel with respect to bolt  22 , however, to an “L” shaped path as will be described subsequently. 
         [0019]      FIG. 2  shows pump assembly  40  removed from pressure vessel  16 . In the assembled state, pump cylinder  18  is trapped inside pressure vessel  16  by vessel cap  14 . Valve  26 , a one-way valve, is at the end of pump cylinder  18  opposite butt stock  12 . Butt stock  12  is attached to piston  16  which slides back and forth within pump cylinder  18 . Vessel cap  14  may be removably attached to pressure vessel  16  by female threading on the inside of vessel cap  14  and male threading on the outside of neck  28  of pressure vessel  16 . 
         [0020]    Pump assembly  40  is shown in greater detail in  FIG. 3 . Pump assembly  40  is generally a positive displacement pump. Air enters cylinder  38  through a one-way valve on the side of cylinder  38  near butt stock  12 . The user manipulates butt stock  12  in a back and forth motion causing piston  42  to travel back and forth within cylinder  38 . When butt stock  12  is drawn all the way to a fully-open intake position, ambient air enters cylinder  38  through the one-way valve. When butt stock  12  is pressed completely forward, such as shown in  FIG. 3 , air within cylinder  38  is compressed and expelled through valve  26 . As mentioned previously, valve  26  is also a one-way valve. Accordingly, the pressure charge that is developed in pressure vessel  16  will not escape through pump assembly  40 . 
         [0021]    Operating pressure for the launcher is limited by the design of pump assembly  40 . V B  represents the total volume of cylinder  38  when the plunger is at full backstroke, or at the fully-open intake position. When the user pushes butt stock  12  into cylinder  38 , V A  represents the total volume of cylinder  38  when piston  42  is pushed as far as possible. At full backstroke, the air in cylinder  38  is at atmospheric pressure. At full forward stroke, or at the fully-compressed compression position, the air in pump housing  38  is V B /V A  times atmospheric pressure. This of course assumes that air does not escape through valve  26  into pressure vessel  16 . When pressure inside pressure vessel  16  is equal to the pressure in cylinder  38  when piston  42  is pushed all the away in, this assumption holds true. As an example, if V B  is twice the size as V A , then pressure vessel  16  can only be pressurized to two times atmospheric pressure. This feature helps prevent injury caused by projectiles launched at dangerous velocities. 
         [0022]    Pressure vessel  16  is sealed on the side opposite pump assembly  40  by a valve which is captured between pressure vessel  16  and bolt  22  as shown in  FIG. 4 . The valve includes valve disk  48  and valve body  36 . Valve disk  48  is preferably made of a flexible material such as rubber, silicone, plastic, or other polymer. Valve disk  48  is substantially annular in shape, having a perimeter and a center bore. Valve disk  48  may be situated within orifice  50  of bolt  22  so that the perimeter of valve disk  48  mates with mating surface  86  of bolt  22  when threaded neck  52  of pressure vessel is threadedly engaged with orifice  50  of bolt  22 . Groove  88  may be optionally provided in mating surface  66  along with a corresponding annular rib on valve disk  48  to ensure alignment and an air-tight seal. 
         [0023]    Bolt  22 , valve disk  48 , pressure vessel  16 , and pump assembly  40  are substantially aligned along a central axis. Bolt pin  30  extends across the interior of bolt  22  transversely to the central axis. Bolt pin  30  is held in place by a pair of pin tabs  32  which project through the outside surface of bolt  22 . Pin tabs  32  serve another function which will be described subsequently. Cutout  34  is provided where the central axis intersects bolt pin  30 . Cutout  34  holds valve body  36  in alignment with valve disk  48  and allows valve body  36  to travel towards and away from valve disk  48 . Valve body  36  includes dome mating surface  48  which mates with valve disk  48  and prevents air from escaping through the center bore. Spring  44  is provided to bias valve body  36  against valve disk  48 . 
         [0024]    When the valve is in the closed position, square sear  56  mates with the back surface of dome mating surface  46  and prevents valve body  36  from opening as the pressure in pressure vessel  16  exceeds the force exerted by spring  44 . Trigger  54  is attached to trigger grip  18  by pivot  60 . Trigger  54  has protrusion  58  which attaches trigger  54  to square sear  56 . When the user pulls trigger  54 , trigger  54  rotates about pivot  60  causing square sear  56  to pull away from the back side of dome mating surface  46 . If pressure vessel  16  has sufficient pressure to overcome the force of spring  44 , the valve will open, and the pressure charge will rapidly expel through valve disk  48  into bolt  22 . 
         [0025]    A perspective view of a section of bolt  22  is provided in  FIG. 5 . Dome mating surface  46  projects upwardly to an apex. In the preferred embodiment, dome mating surface  46  has a convex curvature facing valve disk  48 . This geometry cause valve disk  48  to mate more tightly with dome mating surface  46  as pressure in pressure vessel  16  increases. Spacers  82  are provided around dome mating surface  46  to ensure alignment. Air passages  84  are formed between spacers  82 . Air passages  84  and the convex shape of dome mating surface  46  allow the pressure charge to pass around valve body  36  abruptly when the valve opens. The reader will appreciate that whenever the valve is in the closed position, air passages  84  are covered by valve disk  48 . When square sear  56  is pulled away, however, the pressure charge pushes against dome mating surface  46 , causing valve body  36  to compress spring  44 . This exposes air passages  84  to the pressure charge, and the pressure charge rapidly passes around valve body  36 . This abrupt release of the pressure charge is desirable in order for the soft projectile to shoot out of the projectile launcher with maximum force. 
         [0026]    The valve assembly described previously offers many unique advantages over conventional valves. The valve resets with very little force compared to the pressure limit of the valve. One stroke of the pump reliably forms the seal between valve disk  48  and dome mating surface  46 . Also, the full flow rate resulting from the release of the pressure charge is achieved almost instantly and is measurably faster than the flow rates achievable with a ball valve or gate valve. 
         [0027]    The loading feature for the present invention is shown in greater detail in  FIG. 6 . Barrel  70  is attached around bolt  22  so that it may rotate around the central axis of bolt  22 . Barrel  70  may also travel axially with respect to the central axis of bolt  22 . Pin tab  32  is provided, however, to limit the movement of barrel  70  with respect to bolt  22 . A pair of action slots  72  are provided on opposite sides of barrel  70 . Pin tab  32  acts as a guide and restricts the movement of barrel  70  to an L-shaped path with respect to bolt  22 . Barrel grip  24  is provided to assist the user in manipulating barrel  70 . 
         [0028]    The sidewalls of action slots  72 , defined as the surfaces on barrel  70  which are substantially perpendicular to bolt  22 , may be angled inward (so that the slot is wider on the surface facing bolt  22  than on the outward facing surface of barrel  70 ) to create a better plastic on plastic seal between bolt  22  and barrel  70 . An angle of approximately 2 degrees or greater is particularly effective. 
         [0029]    To load a soft projectile in the projectile launcher, barrel  70  is rotated a quarter of a turn with respect to bolt  22  and advanced forward axially along bolt  22  until the loading port passes over the end of bolt  22 , exposing the hollow interior of barrel  70  (or loading chamber  74 ) as shown in  FIG. 6 . Bolt vents  66  are provided on the end of bolt  22 . Bolt vents  66  allow the pressure charge to pass through bolt  22  into barrel  70  when the pressure charge is released. A soft projectile, such as a marshmallow, may then be loaded into loading chamber  74 . Before pulling the trigger and releasing the pressure charge, the user reverses barrel  70  axially along bolt  22  and then rotates barrel  70  back to its starting position. 
         [0030]    Barrel  70  may be divided into two principal portions when barrel  70  is in the loaded and ready to fire position, as shown in  FIG. 7 . One portion wraps around and mates with the exterior surface of bolt  22 . Action slot  72  and loading port  76  lie in this portion of the barrel. When barrel  70  is in the presently illustrated position, action slot  72  and loading port  76  are sealed off from the interior of barrel  70  by bolt  22 . In the preferred embodiment, bolt  22  and barrel  70  are both made of plastic. A plastic-on-plastic seal is created between bolt  22  and barrel  70  when the components are in the loaded position. 
         [0031]    The second portion of barrel  70  extends beyond the end of bolt  22 . This portion of barrel  70  acts as the muzzle for the projectile launcher. Barrel neck  68  is provided in the interior of the muzzle to compress soft projectile  80  and direct soft projectile  80  through rifled barrel  78  as the pressure charge passes through bolt vents  66  and forces soft projectile  80  out of the projectile launcher. Barrel neck  68  defines the tapered region of barrel  70  between bolt  22  and rifled barrel  78 . The muzzle is rifled to prevent the use of improvised hard projectiles. A hexagonal shaped cross-section is preferred for rifled barrel  78 , although other polygonal shaped cross-sections may also be used. In the preferred embodiment, the hexagonal rifling forms a hexagonal helical pattern as the hexagonally-shaped cross section rotates angularly along the length of the barrel as illustrated in  FIG. 7 . Unless a hard object has the shape of a hexagonal prism and is within a small tolerance of being the same size of the interior of rifled barrel  78 , the hard object will not launch out of the projectile launcher with very much energy. The object will either get stuck in rifled barrel  78  or most of the air from the pressure charge will divert around the object. Soft projectiles will deform to fit through rifled barrel  78 , however, and create an air tight seal when doing so. 
         [0032]    Muzzle brake  62  is another safety feature of the present invention. Muzzle brake  62  extends beyond rifled barrel  78  and has a plurality of brake vents  64 . This feature prevents the user from placing their mouth around the muzzle of the projectile launcher and inhaling the soft projectile or discharging a pressure charge into the user&#39;s lungs. Brake vents  64  prevent the user from creating suction on the muzzle. If the user inhales through the end of muzzle brake  62 , air will simply filter through brake vents  64 . If the user puts the muzzle in a person&#39;s mouth, the pressure charge will be diverted through brake vents  64  and will not be forced into the person&#39;s lungs. 
         [0033]    With the components of projectile launcher  10  now described, the user will appreciate how the launcher is used. The user rotates and slides forward barrel  70 , places a soft projectile in loading chamber  74  in front of bolt  22 , and then slides back and rotates barrel  70  to seal loading port  76 . The user then pumps pump assembly  40  repeatedly until the desired pressure charge is created within pressure vessel  16 . The user then pulls trigger  54  to release the pressure charge into bolt  22  which launches the projectile. The user may also create the desired pressure charge within pressure vessel  16  first before loading the projectile into loading chamber  74 . 
         [0034]    The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. As an example, many different types of pumps may be used to create the pressure charge. Such variations would not alter the function of the invention. Thus, the scope of the invention should be fixed by the following claims, rather than by the examples given.