Abstract:
A gas valve that can be opened using a trigger mechanism. When triggered, the valve is preferably configured to deliver a rapid release of air and then reset itself in the closed state. Once in the closed state, pressure may again be built on the upstream side of the valve until another release is desired.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    Not Applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable 
       MICROFICHE APPENDIX 
       [0003]    Not Applicable 
       BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
       [0004]    This invention relates to the field of valves. More specifically, the present invention comprises a valve assembly configured for a rapid release of pressure when a triggering mechanism is actuated. 
       2. Description of the Related Art 
       [0005]    The present invention has application wherever a pressurized gas needs to be selectively released. One non-limiting application is that of soft projectile launchers. A soft-projectile launcher is commonly used by children for target practice and for war-type games. The projectile may be a piece of compressible foam or a marshmallow. 
         [0006]      FIGS. 1-3  depict a marshmallow shooter incorporating the present invention. These figures are not labeled as “prior art” because the marshmallow shooter includes the novel inventive valve. However, those skilled in the art will realize that the marshmallow shooter includes many prior art features. These features will be described in this “BACKGROUND” section and the novel features will then be described in later sections. 
         [0007]      FIG. 1  illustrates a projectile launcher  12  incorporating the inventive valve. The projectile is fired through barrel  16  and out of muzzle  18 . Reservoir/pump assembly  20  stores a volume of compressed air. Pump handle  24  is used to pressurize the air within the reservoir. Valve assembly  22  regulates the flow of gas to launch the projectile. Trigger  14  selectively releases the gas. Grip  12  allows the user to easily grip the projectile launcher while keeping a finger on the trigger. Carry handle  46  allows the user to easily grasp and carry the launcher. 
         [0008]      FIGS. 2 and 3  are sectional elevation views through the launcher. They are intended to show the features of the launcher other than the inventive valve, so that the reader may understand one operational environment in which the inventive valve may be used (but by no means the only operational environment). The inventive valve itself will be described subsequently. Many of the components depicted in  FIGS. 2 and 3  are also shown in simplified form for purposes of visual clarity. 
         [0009]    In  FIG. 2 , reservoir  26  is designed to contain a pressurized air supply. The user builds pressure by grasping pump handle  24  and cycling piston  34  and rod  30  in pump cylinder  28 . As the user pulls pump handle  24  rearward, air passes through vent  32  and through first check valve  36 . This air flows into the volume to the left of piston  34  (with respect to the orientation shown in the view). Second check valve  38  remains closed during the rearward stroke. Once the pump handle reaches the rearward limit of its stroke, the user pushes it forward. At this point increasing pressure ahead of piston  34  causes first check valve  36  to close. The volume ahead of the piston is thereby pressurized. 
         [0010]    As the forward stroke of the piston continues the increasing pressure ahead of the piston exceeds the pressure within reservoir  26  and second check valve  38  opens. The air ahead of the piston then flows through second check valve  38  into reservoir  26 . This cyclic pumping action may be repeated through multiple strokes. Eventually the pressure within reservoir  26  will build to the point that pump cylinder  28  is no longer able to add additional pressure. 
         [0011]    Valve assembly  22  controls the flow of air out of reservoir  26 . In the invention, trigger  14  is pulled to open the valve assembly and release the pressure within the reservoir into firing chamber  42 . A soft projectile located within firing chamber  42  (not shown in  FIG. 2 ) is propelled by the released air into bore  40  and out muzzle  18 . 
         [0012]      FIG. 3  shows how a soft projectile is loaded into the launcher. In the embodiment shown, a release catch is actuated and barrel assembly  48  pivots downward about hinge pin  44 . Breach  50  is thereby exposed. A projectile  52  is loaded into breach  50  and barrel assembly  48  is then rotated upward and latched into place (as shown in  FIG. 2 ). The user then launches the projectile by pulling the trigger. 
         [0013]    A launcher such as shown in  FIGS. 1-3  will benefit from a trigger-actuated valve providing a controlled release of pressure. The present invention provides such a valve. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0014]    The present invention comprises a gas valve that can be opened using a trigger mechanism. When triggered, the valve is preferably configured to deliver a rapid release of air and then reset itself in the closed state. Once in the closed state, pressure may again be built on the upstream side of the valve until another release is desired. 
         [0015]    A movable valve body defines the open and closed state of the valve. The valve body moves within a surrounding housing. Pressure accumulates on the upstream side of the valve. When the valve is triggered, the valve body moves in the downstream direction and releases the pressurized gas in the downstream direction. A positive seal is created by the mating of an upstream conical surface on the valve body and a downstream conical surface on a seal held in place in the surrounding housing. The valve body is maintained in the closed state by a movable sear. A trigger mechanism moves the sear out of the way in order to open the valve. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0016]      FIG. 1  is a perspective view, showing a typical application for the inventive gas valve assembly. 
           [0017]      FIG. 2  is a sectional elevation view, showing how the inventive valve assembly can be used in a projectile launcher. 
           [0018]      FIG. 3  is a sectional elevation view, showing how the projectile launcher of  FIG. 2  is loaded. 
           [0019]      FIG. 4  is a perspective view, showing a valve body used in the inventive valve assembly. 
           [0020]      FIG. 5  is a sectional elevation view, showing the valve body of  FIG. 4 . 
           [0021]      FIG. 6  is a sectional elevation view, showing the components of the inventive valve assembly in a closed state. 
           [0022]      FIG. 7  is a sectional elevation view, showing the components of the inventive valve assembly in an open state. 
           [0023]      FIG. 8  is a sectional elevation view, showing the components of the inventive valve assembly in an open state. 
           [0024]      FIG. 9  is a sectional elevation view, showing a detail of how the valve is sealed. 
       
    
    
     REFERENCE NUMERALS IN THE DRAWINGS 
       [0025]      10  projectile launcher 
         [0026]      12  grip 
         [0027]      14  trigger 
         [0028]      16  barrel 
         [0029]      18  muzzle 
         [0030]      20  reservoir/pump assembly 
         [0031]      22  valve assembly 
         [0032]      24  pump handle 
         [0033]      26  reservoir 
         [0034]      28  pump cylinder 
         [0035]      30  rod 
         [0036]      32  vent 
         [0037]      34  piston 
         [0038]      36  first check valve 
         [0039]      38  second check valve 
         [0040]      40  bore 
         [0041]      42  firing chamber 
         [0042]      44  hinge pin 
         [0043]      46  carry handle 
         [0044]      48  barrel assembly 
         [0045]      50  breach 
         [0046]      52  projectile 
         [0047]      54  valve body 
         [0048]      56  disk 
         [0049]      58  column 
         [0050]      60  spring retainer 
         [0051]      62  rib 
         [0052]      64  spring retainer surface 
         [0053]      66  stop surface 
         [0054]      68  upstream conical surface 
         [0055]      70  downstream housing 
         [0056]      72  upstream housing 
         [0057]      74  pivot 
         [0058]      76  sear 
         [0059]      78  passage 
         [0060]      80  actuator tip 
         [0061]      82  threaded engagement 
         [0062]      84  spring 
         [0063]      86  spring retainer 
         [0064]      88  seal 
         [0065]      90  flexible extension 
         [0066]      92  central axis 
         [0067]      94  downstream conical surface 
         [0068]      96  retention feature 
         [0069]      98  upper surface 
         [0070]      100  annular groove 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0071]    The present invention provides a valve for controlling the flow of a compressed gas such as air. The valve&#39;s operation depends upon the position of a movable valve body.  FIG. 4  shows this component—denoted as valve body  54 . The sealing functions are carried out by disk  56 . An elongated column  58  connects disk  56  to a cruciform spring retainer  60 . Four ribs  62  are provided for purposes of stiffening the structure and maintaining the proper location of an associated compression spring. Stop surface  66  stops the downstream motion of the valve body when the valve is opened. Spring retaining surface  64  bears against the aforementioned compression spring. 
         [0072]      FIG. 5  shows a sectional elevation view through the valve body—taken through the plane of two of the ribs  62 . The reader will observe that disk  56  includes an upstream conical surface  68  (The term “upstream” meaning that this conical surface faces in the “upstream” direction with respect to the flow of gas through the valve). The reader will also note the positions of stop surface  66  and spring retainer surface  64 . The functions of these geometric features will be apparent from reviewing the completed assembly. 
         [0073]      FIG. 6  shows a sectional elevation view through an exemplary embodiment of a complete assembly. The inventive valve mechanism is preferably contained within an appropriate housing. The housing may be part of a larger device or it may be free-standing. In the embodiment of  FIG. 6  the housing is part of a larger device and is in fact split into two pieces. Upstream housing  72  serves to position components of the valve assembly and also serves as part of the reservoir  26  of a projectile launcher. Downstream housing  70  serves to position components of the valve assembly and also serves as a mount for the trigger mechanism and other portions of the projectile launcher. The two housings are united by threaded engagement  82 . 
         [0074]    The valve assembly in this embodiment is preferably radially symmetric about central axis  92 . For example, seal  88  assumes the general form of an O-ring. The valve is shown in a closed state. In the embodiment shown, valve body  54  moves to the left along central axis  92  when the valve is opened (To the left in the view is the “downstream” direction and to the right is the “upstream” direction). Pressure is built within reservoir  26 . This is denoted as P 1 . The pressure downstream of the valve in the embodiment shown in simply the ambient air pressure—denoted as P 2 . The sealing of the valve in the closed state is accomplished by a portion of seal  88  being urged against upstream conical surface  68  on valve body  54 —as indicated by the arrows. As P 1  increases with respect to P 2  the force urging seal  88  again upstream conical surface  68  increases. 
         [0075]    Seal  88  is an annular ring made of flexible material. Exemplary materials include natural rubber, synthetic rubber, and silicon. It preferably incorporates mechanical interlocking features to hold it in position. In this example, a downstream-facing protrusion on seal  88  fits into an annular cavity in an upstream-facing portion of downstream housing  70 . Spring retainer  86  compresses a portion of seal  88  against downstream housing  70  to hold it in place. 
         [0076]    Spring retainer  86  is clamped in position as threaded engagement  82  is tightened. The compressible nature of seal  88  provides a positive retaining force for the assembly similar to the function of a lock washer. The reader will note that spring retainer  86  includes features configured to positively locate compression spring  84 . Spring  84  bears against spring retainer surface  64  on valve body  54 . The spring thereby holds valve body  54  in the closed position shown. 
         [0077]    Of course, as pressure within reservoir  26  builds the closing force of spring  84  will be overcome and the valve will crack open—much like a pressure regulating valve. This action is not desired in the present invention. One goal of the present invention is the sharp release of a significant pressure differential. In order to accomplish this goal, an additional mechanism is provided to hold valve body  54  in the closed position. 
         [0078]    Sear  76  moves substantially transversely to central axis  92  (“substantially” herein defined as meaning within 20 degrees of perpendicular to central axis  92 ). The sear is shown in the latched position in  FIG. 6 —holding the valve in the closed state. In the embodiment shown, sear  76  slides up and down within an enclosing channel in downstream housing  70  (The terms “up” and “down” are stated with respect to the orientation of the view and should not be read as limiting). Valve body  54  is forced against the sear as the pressure within reservoir  26  increases. The forces acting on the sear are transmitted to housing  70  so that the sear is retained in position. 
         [0079]    The sear also contains a passage  78  (such as a transverse slot through the sear). Actuator tip  80  of trigger  14  rests within passage  78 . Trigger  14  pivots about pivot  74 , which is also secured to downstream housing  70  in this embodiment. When the user pulls the lower portion of the trigger, actuator tip  80  moves downward. This motion urges sear  76  downward until it is no longer engaged with valve body  54 . This motion “fires” the valve. 
         [0080]      FIG. 7  shows the “firing cycle” of the valve. At the point shown sear  76  has been pulled out of engagement with valve body  54 . The pressure differential across the valve body then forces it downstream (to the left in the view). Upstream conical surface  68  on disk  56  moves out of engagement with seal  88  and allows air to flow through the valve as indicated by the curving arrows. Spring  84  is compressed by spring retention surface  64  on valve body  54 . Depending on the rate of flow, the compression of spring  84  may be enough to arrest the further downstream movement of valve body  54 . If spring compression alone is insufficient, the reader will note that stop surface  66  (on the valve body) will eventually come to rest against the upstream extreme of spring retainer  86  and limit any further downstream movement of the valve body. The reader will also note how the structure of spring retainer  86  keeps the spring in alignment and prevents any buckling deformation of the spring. 
         [0081]    The section plane in the view of  FIG. 7  passes through two of the ribs on valve body  54  and this produces a somewhat deceptive depiction. In  FIG. 7  it appears that relatively little free passage room is available for the gas escaping through the opened valve. This is actually not the case. Returning to  FIG. 4 , the reader will note that the section “call out” for  FIG. 8  selects a section view plane that does not pass through ribs  62 . Looking now at  FIG. 8 , the reader will observe that significant clearance exists for the gas passing through the open valve. Column  58  of valve body  54  occupies relatively little volume. In this example the valve body is free to rotate so the section plane chosen for the valve body is somewhat arbitrary. 
         [0082]    Returning to  FIG. 7 , the completion of a “firing cycle” will be explained. Once the compressed gas within the reservoir is vented through the valve, spring  84  tends to urge valve body  54  back upstream. Upper surface  98  of sear  76  is preferably given an angled shape as shown. Upstream conical surface  68  of valve body  54  bears against angled surface  98  (as the valve body moves toward the closed position) and urges sear  76  downward (if necessary) so that valve body  54  can return to its upstream (closed) position. Sear  76  may be provided with a return spring tending to urge it upward (All directional terms such as “upward” should be understood as referring only to the orientation shown in the particular view and should not be read as limiting). Once upstream conical surface  68  passes over upper surface  98 , sear  76  pops upward (assuming the sear is equipped with a return spring). The configuration of  FIG. 6  is thereby restored. The valve in this state is ready to remain in the closed position until the trigger is pulled again. 
         [0083]    The inventive valve assembly preferably includes some features intended to ensure a positive seal.  FIG. 9  is a detailed view showing the upper portion of  FIG. 6  in greater detail. Seal  88  preferably includes one or more retention features  96  (in this case a protruding portion). Downstream housing  70  in this example includes an annular groove  100  configured to receive a retention feature  96  on seal  88 . Seal  88  is thereby positively located. 
         [0084]    Seal  88  also includes a flexible extension  90  extending inward toward the central axis of the valve assembly. This flexible extension includes downstream conical surface  94  (facing to the left in the orientation of the view). Upstream conical surface  68  is shaped to mate against downstream conical surface  94 . As the pressure P 1  increases with respect to P 2  flexible extension  90  is pressed more tightly against upstream conical surface  68 . The reader will note that the interface between downstream conical surface  94  and upstream conical surface  68  is quite long. In other words, in order to escape, air must travel between the two mated surfaces for a long distance rather than just past a short “pinch point.” This elongated interface increases the security of the valve. It is preferable for the mating of the two surfaces to span a range of diameters that is at least one-tenth the overall diameter of disk  56  and even more preferable for the mating to span a range of diameters that is at least one-fourth the overall diameter of disk  56 . 
         [0085]    Other embodiments of the inventive valve may include many other features beyond those shown in the accompanying drawings. These include: 
         [0086]    1. A return spring located on the trigger, the sear, or both; 
         [0087]    2. A dashpot positioned to eliminate cyclic movement of the trigger, the sear, or both; 
         [0088]    3. A mechanism intended to promote cyclic operation of the valve mechanism to trigger a series of multiple, controlled discharges; 
         [0089]    4. A bearing to smooth the motion of the sear; 
         [0090]    5. A multi-link latching sear mechanism; and 
         [0091]    6. A sear that does not move in a direction that is transverse to the central axis of the valve mechanism. 
         [0092]    The example provided in the drawing views uses several molded thermoplastic parts—such as the housings and the valve body. Thermoplastics are suitable for moderate pressures and non-corrosive gases. The inventive valve may be made of other materials for other applications. For example, aluminum or stainless steel could be used for applications requiring higher pressures or temperatures. The seal could even be made of metallic material for high temperature applications. 
         [0093]    The preceding description contains significant detail regarding 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. Thus, the scope of the invention should be determined with reference to the following claims rather than any specific embodiment.