Patent Publication Number: US-7712463-B2

Title: Self-regulating valve assembly

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 60/808,301, filed May 25, 2006, which is incorporated by reference as if fully set forth. 
    
    
     FIELD OF INVENTION 
     This invention relates to valves and valve assemblies. Namely, valves used in compressed gas guns. 
     BACKGROUND 
     Compressed gas guns, such as paintball markers used in the sport of paintball, using compressed gas or air for firing projectiles are well known. As used herein, the term “compressed gas gun” refers to any gun or similar launching mechanism for use in sport wherein a projectile is fired via the force of compressed gas, and includes paintball markers. As used herein, the term “projectiles” refers to both paintballs and other projectiles used in sport and game-play. 
     There are a few basic mechanisms employed in compressed gas guns for firing a projectile during a firing operation. A compressed gas gun generally includes an interior portion including passages for receiving the operating parts of the gun. These passages are often provided as generally cylindrical openings. Loading a projectile into the breech of a compressed gas gun involves a bolt having a bolt passage therethrough that reciprocates from a loading position, allowing a projectile into the breech to a firing position. 
     A valve system is employed to release compressed gas from a source of compressed gas to fire the projectile from the gun. The valve system generally utilizes a hammer or ram that moves under spring force or pneumatic force upon actuation of a trigger to strike the stem of a poppet or Nelson-style valve to allow compressed gas from a compressed gas chamber to flow through the valve body. The compressed gas flows through the opened valve body and through a passage in the bolt, thereby firing a projectile in the breech of the paintball marker from the chamber and down the barrel. While other types of valve systems are employed, generally, most involve directing compressed gas under pressure to fire a projectile from the compressed gas gun. 
     In many cases, compressed gas guns utilize a hammer, striker, or ram arrangement to actuate a poppet-type or valve as the firing valve, i.e., as the valve that releases compressed gas from a compressed gas source to fire a projectile from the gun. A prior art valve  10  is shown in a closed position in  FIGS. 1A and 1B . This type of prior art valve, or a Nelson-style valve, or generally similar variations, have been used in paintball markers (guns) sold under, for example, the brand names INDIAN CREEK DESIGNS, TIPPMANN and BT. Similar valve arrangement, in various orientations, are shown in U.S. Pat. No. 4,936,282 and U.S. Pat. No. 5,257,614. A valve spring  14  is provided, biasing the seat  16  or cup seal of the valve  10  to a closed position. A stem or pin  24  that is attached to the seat  16  or cup seal extends out the rear end of the valve  10 . In known compressed gas guns, a spring biased hammer  12  is provided, retained in a cocked or ready position by a sear  18  that pivots to engage a portion of the hammer  12 . A schematic representation of such a compressed gas gun operation is shown in  FIG. 1A  and the valve is shown in greater detail in  FIG. 1B . Actuation of a trigger  20  (such as by pulling) disengages the sear  18  from the hammer  12 , allowing the hammer  12  to spring forward under the bias force of a hammer spring  22 , to contact the stem  24  of the valve  10 . When the hammer  12  contacts the stem  24 , the seat  16  moves away from the valve body, opening the valve  10 , and allowing compressed gas to flow through the opening in the valve body. These types of compressed gas guns move the hammer back to the loading or start position by “blow back,” i.e., some of the air from a high pressure chamber returns the hammer to the cocked or loading position, thus “blowing” the hammer back to the starting position. 
     As can be appreciated, if pressure inside the valve body increases, there is more force pushing against the valve seat or cup seal. The compressed gas within the valve body exerts a force on the effective surface area of the seat or cup seal  16 , which exerts a force toward the valve pin or stem  24 , thereby tending to keep the valve closed. Thus, a greater force is needed to move the seat or cup seal away from the valve opening to actuate the valve. This mechanism has drawbacks. For example, it requires a heavy hammer propelled forward by a heavy hammer spring. A heavier hammer and hammer spring is needed to overcome the combined force of the compressed gas on the effective surface area of the valve seat or cup seal, combined with the biasing force of the valve spring. In turn, more energy is absorbed from the moving hammer when it hits the valve pin, and more force is required to open the valve. This reduces the amount of time the valve poppet is open. 
     As can be further appreciated, the force of the valve spring must be strong to return the seat of the poppet valve to a closed position. Moreover, the force of the hammer spring moving the hammer must be strong enough overcome the valve spring. This arrangement creates inefficiencies and wastes compressed gas. 
     Accordingly, there remains a need for a valve utilizing a lighter hammer and a lighter main spring in order to reduce the reciprocating mass inside the paintball marker, reduce the weight of the trigger pull, and reduce the force with which the marker chambers a paintball, all while maintaining a stable velocity over a wide range of input pressures. 
     SUMMARY 
     The present invention provides a self-regulating valve assembly. The self-regulating valve assembly includes a valve housing and a valve body disposed within the valve housing. The valve body defines am inlet port for receiving gas under pressure from a gas source and has a rearward end and a forward end. The rearward end defines an outlet port including a seat, and the forward end defines a gas balance reservoir in communication with a firing tube and breech of a compressed gas gun. A valve gas passage is defined between the valve body and the valve housing, the valve gas passage providing communication between the outlet port and the gas balance reservoir of the valve body. A valve poppet is disposed within the valve body and includes a sealing end for contact and sealing engagement with the seat of the valve body in a closed position of the self-regulating valve. The valve poppet further includes a sensing end adjacent the gas balance reservoir, at least a portion of the sensing end slidable within gas balance reservoir, the having a sensing face adapted to react to gas pressure communicated to the gas balance reservoir. The valve poppet is slidable between a closed position and an open position. A valve spring is disposed within the valve body, the valve spring biasing the valve poppet toward the closed position. An increase in pressure in the gas balance reservoir exerts a force on the sensing face of the valve poppet to urge the valve poppet toward the closed position. 
     The present invention further provides a gas gun having a gun body with a rearward end and a forward end. A hammer is disposed within the gun body adjacent the rearward end of the gun body, the hammer having a forward end. The hammer is slidable from a rearward position to a forward position, and the forward end of the hammer is adapted to contact a valve pin. A main spring is disposed within the gun body and biases the hammer toward the forward position. A bolt is disposed within the gun body adjacent the forward end of the gun body, the bolt being slidable from a rearward position to a forward position. A firing tube is partially disposed within the bolt. A self-regulating valve is disposed within the gun body between the hammer and the bolt. The self-regulating valve includes the valve pin extending rearward and the valve pin includes a contact end. A connecting rod connects the hammer and the bolt for synchronized movement between the hammer and the bolt. Release of the main spring urges the forward end of the hammer to its forward position to contact the contact end of the valve pin and shift the self-regulating valve from a closed position to an open position. The forward movement of the hammer causes synchronized forward movement of the bolt via the connecting rod. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are cross-sectional side views of a known poppet valve and hammer assembly, the assembly&#39;s forward end toward the left and its rearward end toward the right as viewed in the figures; 
         FIG. 2  is a cross-sectional side view an embodiment of a gas gun in a ready-to-fire position utilizing a self-regulating valve assembly in accordance with the present invention, the gas gun&#39;s rearward end toward the left and its forward end toward the right as viewed in the figure; 
         FIG. 3  is a detailed view of the self-regulating valve assembly of  FIG. 2 ; 
         FIG. 4  is a cross-sectional side view the gas gun of  FIG. 2  in a firing position; 
         FIG. 5  is a detailed view of the self-regulating valve assembly of  FIG. 4 , along the cut-out labeled “C”; and 
         FIG. 6  is a further detail view of the self-regulating valve assembly of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of this detailed description, all reference to direction or orientation are from the perspective of a user firing a compressed gas gun by holding the gun upright in its normal firing position. For example, “rear” or “rearward” refers to a portion or portions closer to the user, and “forward” refers to a portion or portions farther away from the user (i.e., more toward the barrel than the grip, trigger, or hammer). 
     The preferred embodiments of the present invention are described below with reference to the drawing figures where like numerals represent like elements throughout. 
     Referring generally to  FIGS. 2 and 4 , a gas gun  30  having a gun body  32  with a rearward end  34  towards its grip  36  and a forward end  38  towards its barrel  40  is shown. The gun body  32  includes a generally cylindrical interior passage or space for receiving at least some of the firing components (e.g., the hammer and valving components) of the gun  30 .  FIG. 2  represents the gas gun  30  with the components in a ready-to-fire position, and  FIG. 4  represents the gas gun  30  with the components in a firing position. Projectiles, such as paintballs  42 , are also shown. The gun body  32  includes a feed inlet port  43  through which projectiles  42  feed into the breech  39  of the gun  30 . 
     A hammer  44  (sometimes referred to in the art as a ram or striker) is disposed within the gun body  32  adjacent the rearward end  34  of the gun body  32 , the hammer  44  having a forward end  46  facing the self-regulating valve  60  of the present invention. The forward end  46  of the hammer  44  is adapted to contact a valve pin  48  (also referred to as a stem), which will be described in greater detail below. 
     The hammer  44  is slidable from a rearward position (as shown in  FIG. 2 ) to a forward position (as shown in  FIG. 4 ). More specifically, a main hammer spring  50  is disposed within the gun body  32  and biases the hammer  44  toward the forward or firing position. The hammer  44  is retained in a cocked or ready position by a sear  52  that pivots to engage a portion of the hammer  44 , as shown in  FIG. 2 . Actuation of a trigger  54  (such as by pulling the trigger) disengages the sear  52  from the hammer  44 , allowing the hammer  44  to spring forward under the bias of the main hammer spring  50 , as shown in  FIG. 4 . The main hammer spring  50  may be positioned to travel along a post or spring guide to maintain the main hammer spring  50  in position. 
     A bolt  56  is disposed within the gun body  32  and slidable within the breech  39  of the gun  30 , preferably adjacent the forward end  38  of the gun body  32  adjacent the barrel  40 , the bolt  56  being slidable from a rearward position ( FIGS. 2 and 3 ) to a forward position ( FIGS. 4 and 5 ) to open and close the breech  39  of the gun. A firing tube  58  is partially disposed within the bolt  56 , such that the bolt  56  coaxially surrounds the firing tube  58 . 
     The self-regulating valve  60  of the present invention is preferably disposed within the gun body  32  between the hammer  44  and the bolt  56 . although, as discussed below, the valve  60  could be positioned in different orientations based on the arrangement of a particular compressed gas gun. The self-regulating valve  60  (described in greater detail below) includes the valve pin  48  extending rearward toward the hammer  44 , the valve pin  48  including a contact end  62 . A connecting rod  64  connects the hammer  44  and the bolt  56  for synchronized movement of the hammer  44  and the bolt  56 . The connecting rod  64  provides a mechanical linkage between the hammer  44  and the bolt  56 . 
     As illustrated in  FIGS. 3 ,  5 , and  6 , the self-regulating valve  60  assembly includes a valve housing  66  and a valve body  68  disposed within the valve housing  66 . The valve body  68  includes an inlet port  70  for receiving gas under pressure from a compressed gas source and has a rearward end  72  and a forward end  74 . The rearward end  72  includes an outlet port  76  for communicating gas under pressure from within the valve body  68  when the valve  60  is actuated or open. A seat  78  (represented in detail in  FIGS. 5 and 6 ) is provided adjacent the outlet port  76 . The forward end  74  of the valve body  68  includes a gas balance reservoir  80  open to and in communication with the firing tube  58 . At least one valve gas passage  82  (represented in detail in  FIGS. 3 and 5 ) is provided between the valve body  68  and the valve housing  66 , the valve gas passage  82  providing communication between the outlet port  76  of the valve body  68  and the gas balance reservoir  80  of the valve body  68 . In addition, the valve gas passage  82  provides communication between the outlet port  76  of the valve body  68  and the firing tube  58 , so that gas released from the self-regulating valve  60  through the outlet port  76  passes to both the gas balance reservoir  80  of the valve body  68  and to the firing tube  58  to fire a projectile  42  from the gun  30 . 
     A valve poppet  84  is disposed within the valve body  68  and includes a sealing end  85  for contact with the seat  78  of the valve body  68  in a closed position of the self-regulating valve  60 , as shown in  FIGS. 2 and 3 . A sealing member such as a cup seal  86  (labeled in  FIGS. 3 ,  5 , and  6 ) is provided at the sealing end  85  of the valve poppet  84  to assist in preventing the passage of gas from the inlet port  70  of the valve body  68  to the valve gas passage  82  when the self-regulating valve  60  is in the closed position. An o-ring may also be used in addition to the cup seal  86 . The valve poppet  84  further includes a sensing end  88  adjacent the gas balance reservoir  80 , the sensing end  88  having a sensing face  90  (represented most clearly in  FIGS. 3 ,  5 , and  6 ) preferably facing the forward end  38  of the gun  30  and adapted to react to gas pressure within the gas balance reservoir  80 , as described below. The sensing end  88  of the valve poppet  84  is free to move from a rearward position (as shown in  FIG. 3 ) to a forward or firing position (as shown in  FIG. 6 ) within the gas balance reservoir  80 . The sensing end  88  may be fitting with an o-ring to assist in keeping compressed gas from passing from within the valve body  68  to the gas balance reservoir  80 . 
     The effective surface area of the valve poppet  84  upon which compressed gas acts (e.g., the surface area facing forwardly in the exemplary Figures) within the valve body  68  is reduced as compared to prior art valves. Notably, at least a portion of the sensing end  88  of the valve poppet  84 , and specifically the sensing face  90 , is effectively “outside” of the valve body  68 , and is freely moveable within the gas balance reservoir  80 . Therefore, the sensing face  90  portion of the valve poppet  84 , which in a prior art arrangement would be a forwardly facing portion of a cup seal within the valve body, does not contribute to the effective surface area upon which the compressed gas acts within the valve body  68  keeping the seal  86  closed. This reduces the force of the compressed gas on the valve body  68 , and in particular, the force on the seal  86 . 
     The valve poppet  84  is slidable between a closed position ( FIGS. 2 and 3 ) and an open position ( FIG. 4-6 ). A valve spring  92  is disposed within the valve body  68 , the valve spring  92  biasing the valve poppet  84  toward the closed position, as shown in  FIGS. 2 and 3 . A lateral screw  94  for adjusting the velocity of gas within the firing tube  58  protrudes as shown in  3 ,  5 , and  6 . 
     In the ready-to-fire state of the gas gun  30 , the pressure within the gas balance reservoir  80  and the firing tube  58  is ambient (e.g., to atmosphere), and therefore, the sensing end  88  of the valve poppet  84  does not have increased pressure exerted against the sensing face  90 . Thus, in this ready-to-fire state, pressure within the valve body  68  on the valve poppet  84  will be reduced as compared to known valves, as the effective surface against which compressed gas can act (e.g., the surfaces of the seal  86  facing forwardly in the exemplary arrangement in the Figures) is reduced as compared to prior art valves. The force required to keep the valve poppet  84  sealed is thereby minimized by the arrangement of the present invention, with the primary force exerted on the valve poppet  84  provided through the bias of the valve spring  92 . The arrangement of the present invention provides for a valve  60  where minimal pressure is need on the stem  48  of the valve poppet  84  when firing. 
     A source of compressed gas, such as a CO 2  or NO 2  canister (“gas tank” or “air tank”) (not shown), is hooked to an air intake portion  31  of the gun  30 , shown beneath the grip  36 , and supplies gas under pressure through the inlet port  70  to pressurize the confined area within the valve body  68 . 
     In use, actuation of the trigger  54  disengages the sear  52  from the hammer  44 , allowing the hammer  44  to spring forward under the bias of the main hammer spring  50 , as shown in  FIG. 4 . It is appreciated that the trigger and sear arrangement can be of any arrangement known in the art, whether mechanically, electrically or electronically operated. Release of the main hammer spring  50  urges the forward end  46  of the hammer  44  to its forward position to contact the contact end  62  of the valve pin  48  and shift the self-regulating valve  60  from a closed position ( FIGS. 2 and 3 ) to an open position ( FIGS. 4-6 ). The forward movement of the hammer  44  causes synchronized forward movement of the bolt  56  via the connecting rod  64 . The forward movement of the bolt  56 , in turn, causes forward movement and loading of the projectile  42  in the breech  39 , chambering a projectile  42 , as shown in  FIG. 4 . 
     In the open (or firing) position of the self-regulating valve  60 , the cup seal  86  is unseated from the seat  78  of the outlet port  76 , releasing the compressed gas supplied within the valve body  68  through the inlet port  70 . The gas travels through the outlet port  76  (in a rearward direction in the exemplary shown in the Figures), around a portion of the valve body  68 , and through the valve gas passage  82  (in a forward direction in the exemplary shown in the Figures). The gas under pressure then flows into the gas balance reservoir  80  and through the firing tube  58 . Pressure from the compressed gas in the firing tube  58  increases to a level at which a projectile  42  chambered in the gas gun  30  is fired down the barrel  40  and from the gun  30 . 
     As gas flows through the valve gas passage  82 , prior to the projectile  42  being fired, the area of the gas balance reservoir  80  and through the firing tube  58  rearward of the projectile  42  will experience an increase in pressure. This increased pressure will act on the sensing face  90  of the sensing end  88  of the valve poppet  84 . In this manner, when the valve  60  is opened for firing (such as when the hammer  44  strikes the stem  48 ), some of the gas pressure will act on the sensing face  90  of the sensing end  88  of the valve poppet  84  to assist in closing the valve poppet  84  (e.g., biasing the valve poppet  84  rearward to close the valve  60 ). 
     Because there is a minimized force holding the valve poppet  84  closed in the ready-to-fire state, a relatively light hammer  44  and main hammer spring  50  can be utilized to control opening of the valve poppet  84 . Use of the configuration of the present invention as a replacement for certain conventional valve assemblies (e.g., Nelson-style), would provide an improved way in which the valve of a compressed gas gun is able to compensate for increased or decreased pressure in the valve chamber or within the gun body. The sensing face  90  of the valve poppet  84  of the self-regulating valve  60  acts to balance the amount of force holding the valve poppet  84  closed. In the ready-to-fire state, the sensing face  90  is open to ambient pressure. During a firing operation, gas under pressure acts within the gas balance reservoir  80  against the sensing face  90  to provide assistance to the valve spring  92  in closing the self-regulating valve  60 . 
     The sensing face  90  of the valve poppet  84  regulates the amount of time the self-regulating valve  60  is open. As explained above, the hammer  44  strikes the valve pin  48 , thereby opening the valve poppet  84 , and compressed gas travels around the valve body  68  through the valve gas passage  82  toward the firing tube  58 . As the gas balance reservoir  80  receives gas under pressure, the gas exerts a force on the sensing face  90  of the valve poppet  84 , helping (in conjunction with the bias of the valve spring  92 ) to shift the valve poppet  84  to its closed position (rearward in the exemplary Figures). The higher the pressure, the more quickly the self-regulating valve  60  will close. Conversely, the lower the pressure, the more slowly the self-regulating valve  60  will close. 
     The self-regulating valve  60 , in essence, acts as a balanced piston regulator, sensing the pressure build-up directly behind the projectile  42 . In this manner, the self-regulating valve  60  can adjust to paintballs  42  that fit tightly within the breech  39  and require a shorter burst of gas to propel the paintball  42 . Furthermore, the self-regulating valve  60  can adjust to higher or lower input pressures. 
     The valve housing  66  may include a velocity adjusting screw  94  extending through the body of the gun  30 . This screw  94  is accessible to a user. Through adjustment of the velocity adjusting screw  94 , the user can regulate the amount of gas flow from the valve gas passage  82  into the firing tube  58 , thereby adjusting the velocity of a projectile  42  fired from the gas gun  30 . 
     Advantages of the self-regulating valve  60  of the present invention include, among other things, the ability to use a lighter hammer  44  (about 60% lighter than conventional hammers), a lighter main hammer spring  50 , and a lighter trigger  54  pull (due to the lighter main hammer spring  50 ). A paintball marker gun  30  utilizing the self-regulating valve  60  will have less likelihood to “chop” projectiles such as paintballs due to the lighter main hammer spring  50 , and will produce less kick due to the lighter hammer  44  and lighter main hammer spring  50 . Less air is required to re-cock (such as through “blow-back”) the marker  30  due to the lighter hammer  44  and lighter main hammer spring  50 . A stable velocity of compressed gas used for firing a projectile is achieved due to the self-regulating nature of the self-regulating valve  60 . Furthermore, the self-regulating valve  60  of the present invention can operate using CO 2  or compressed gas without the need for regulators or expansion chambers. The self-regulating valve  60  of the present invention itself can act to regulate gas pressures and valve operation. 
     It is appreciated that the self-regulating valve  60  of the present invention can be used to replace valves used in variously arranged compressed gas guns. For example, U.S. Pat. No. 7,159,585 (“Firing Assembly for Compressed Gas Operated Launching Device”), the entire contents of which is incorporated by reference herein, shows both a closed bolt and a “stacked tube” or “over/under” operating compressed gas gun using a poppet valve. The hammer of U.S. Pat. No. 7,159,585 is operated by compressed gas, rather than a hammer spring. The self-regulating valve  60  of the present invention could be used as a replacement for the poppet valve shown in U.S. Pat. No. 7,159,585, allowing for a lighter hammer, and decreased gas pressure necessary to move the hammer. The self-regulating valve  60  of the present invention can be used in any compressed gas gun arrangement where a hammer, striker, or ram is utilized, and in any closed-bolt or open-bolt arrangement. Similarly, the self-regulating valve  60  of the present invention can be modified, with different ports, seat and seal arrangements providing for controlled gas flow in various directions. 
     While the preferred embodiments of the invention have been described in detail above, the invention is not limited to the specific embodiments described which should be considered as merely exemplary. Further modifications and extensions of the present invention may be developed and all such modifications are deemed to be within the scope of the present invention as defined by the appended claims.