Valve for gas operated gun
In a paintball gun 10 the valve member 17 which controls communication between the gas canister 13 and the barrel 11 of the gun is balanced by a piston 23 . When the chamber 21 is pressurized the piston 23 helps to unseat the valve member 17 when the latter is struck by a hammer 15 , thus reducing recoil and permitting use of lighter, less robust materials.
1. A valve assembly for a gas operated gun of the kind having a barrel, a trigger, a chamber having an inlet in communication with a source of gas under pressure, an outlet communicating with the barrel and a valve member having a surface area exposed to the interior of the chamber and controlling the outlet biased to the closed position but which is unseated when the trigger is pulled to allow pressurized gas to expel a pellet from the barrel, wherein the valve assembly comprises a piston reciprocable in a bore open at one end to said chamber, the piston having a surface area exposed to the interior of the chamber not greater than the surface area of said valve member exposed to the interior of the chamber and a mechanical connection between the piston and the valve member such that pressurized gas in the chamber acting on the piston will have an unseating influence on the valve member.
2. A valve assembly as claimed in claim 1 , wherein the valve member and piston are at opposite ends of the chamber, the mechanical connection being a rod extending therebetween.
3. A valve assembly as claimed in claim 2 , wherein the valve member is biased to the closed position by a spring in said bore acting on the piston.
4. A valve assembly as claimed in claim 1 , wherein the valve member has on its face exposed from the chamber a projection which is struck by a hammer when the trigger is pulled.
5. A valve assembly as claimed in claim 4 , wherein the hammer moves jointly with a bolt reciprocable in the barrel to select a paintball from a magazine thereof above the barrel, and wherein gas under pressure from said outlet of the chamber passes through the bolt to expel a selected paintball from the barrel.
6. A valve assembly as claimed in claim 1 , wherein the surface area of the piston exposed to the interior of the chamber is less than the surface area of the valve member exposed to the interior of the chamber.
7. A valve assembly as claimed in claim 6 , wherein the ratio of said surface areas is in the region of 1:2.
8. A valve assembly for a gas operated gun of the kind having a barrel, a trigger, a chamber having an inlet in communication with a source of gas under pressure, an outlet communicating with the barrel and a valve member having a surface area exposed to the gas pressure in the chamber and controlling the outlet biased to the closed position but which is unseated when the trigger is pulled to allow pressurized gas to expel a pellet from the barrel, wherein the valve assembly comprises a piston reciprocable in a bore exposed at one end to the gas pressure in the chamber, the piston having a surface area exposed to gas pressure in the chamber not greater than the surface area of the valve member exposed to the gas pressure in the chamber and a mechanical connection between the piston and the valve member such that pressurized gas in the chamber acting on the piston will have an unseating influence on the valve member.
9. A valve assembly as claimed in claim 8 , wherein the valve member and piston are at opposite ends of the chamber, the mechanical connection being a rod extending therebetween.
10. A valve assembly as claimed in claim 9 , wherein the valve member is biased to the closed position by a spring in said bore acting on the piston.
11. A valve assembly as claimed in claim 8 , wherein the valve member has a projection which is struck by a hammer when the trigger is pulled, thereby unseating the valve member.
12. A valve assembly as claimed in claim 11 , wherein the hammer moves jointly with a bolt reciprocable in the barrel to select a paintball from a magazine thereof above the barrel, and wherein gas under pressure from said outlet of the chamber passes through the bolt to expel a selected paintball from the barrel.
13. A valve assembly as claimed in claim 8 , wherein the surface area of the piston exposed to the gas pressure in the chamber is less than the surface area of the valve member exposed to the gas pressure in the chamber.
14. A valve assembly as claimed in claim 13 , wherein the ratio of the surface areas is in the region of 1:2.