Mechanism for gas operated gun

Abstract

The tubular bolt of a paintball gun communicates with a cylinder through bores when in a forward, firing position, allowing compressed gas from the cylinder to expel a paintball. In accordance with the invention a bore whereby the cylinder communicates with a source of compressed gas is occluded by the bolt when the bolt is in the firing position. By this arrangement only gas stored in the cylinder is used to fire a paintball and the source of compressed gas is not in communication with the cylinder except when the trigger is released and the bolt is in its retracted position.

What is claimed is:  
     
         1 . A mechanism for a gas operated gun having a housing and a trigger, the mechanism comprising a sleeve fixed relative to the housing, a hollow bolt slideable in the sleeve between a firing position when the trigger is pulled and a retracted position when the trigger is released and a cylinder in the sleeve surrounding the bolt, the bolt being adapted when in the retracted position to permit communication between the cylinder and a source of fluid under pressure while isolating the cylinder from the interior of the bolt and when in the firing position to isolate the cylinder from said source while communicating the cylinder with the interior of the bolt.  
     
     
         2 . A mechanism as claimed in  claim 1 , wherein the bolt is slideable on an air fill tube fixed relative to the housing, an O-ring seal being provided between the tube and the bolt, the tube having one or more radial opening rearward of said seal in communication with said source and the bolt having one or more radial opening which will move from one side to the other of said seal as the bolt moves between its firing and retracted positions, the arrangement being such that in the retracted position of the bolt the cylinder communicates with said source through the openings in the tube and bolt while the seal prevents communication between the cylinder and the interior of the bolt and such that in the firing position of the bolt the opening in the tube is occluded by the bolt and the opening in the bolt communicates the cylinder with the interior of the bolt.  
     
     
         3 . A mechanism as claimed in  claim 1 , wherein the sleeve has a radial opening isolated from the cylinder and in communication with said source and the bolt has a circumferential recess positioned and dimensioned so that only when the bolt is in its retracted position the recess will communicate said port with the interior of the cylinder.  
     
     
         4 . A mechanism as claimed in  claim 3 , wherein said port is located in the sleeve rearwardly of the cylinder and communicates with said source via a passageway external to the cylinder and extending axially thereof.  
     
     
         5 . A mechanism as claimed in  claim 1  and comprising a radial bore in the sleeve isolated from the cylinder and in communication with said source, the outer periphery of the bolt having an axially elongated circumferential depression which, in the retracted position of the bolt communicates said bore with the cylinder, the arrangement being such that in the firing position of the bolt said bore is occluded by the bolt while the cylinder is communicated with the interior of the bolt.  
     
     
         6 . A mechanism as claimed in  claim 5 , wherein the cylinder has front and rear openings to the bolt, the front opening aligning with an opening of the bolt in the firing position of the latter and the rear opening aligning with said depression in the retracted position of the bolt.  
     
     
         7 . A mechanism as claimed in  claim 1 , wherein the cylinder is open to the bolt throughout its length and wherein said opening of the bolt takes the form of a circumferential array of holes in the bolt which will be exposed to the cylinder in the firing position of the bolt.  
     
     
         8 . A mechanism as claimed in  claim 1 , wherein means for displacing the bolt between its firing and retracted positions surrounds the bolt in front of or behind said cylinder.