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.