Firearm having an improved gas-operated action

Abstract

A shotgun includes a gas-operated action. The gas operated action includes a cylinder having at least one wall, a piston, and a resilient member. The resilient member is positioned between the piston and the wall of the cylinder to prevent high pressure gas from escaping between the piston and the wall of the cylinder. The resilient member and any surface that the resilient member is in contact with do not move relative to each other when the piston moves.

1 . A gas-operated firearm comprising:
 an action;   a cylinder that fills with high pressure gas when a cartridge is fired, the cylinder including a wall;   a piston positioned in the cylinder and configured to move in response to the hill pressure gas in the cylinder, the piston supplying force to operate the action of the firearm; and   a resilient member positioned between the piston and the wall of the cylinder to prevent the high pressure gas from escaping between the piston and the wall of the cylinder;   wherein the resilient member and any surface that the resilient member is in contact with do not move relative to each other when the piston moves.   
   
   
       2 . The gas-operated firearm of  claim 1  wherein the action is an automatic action. 
   
   
       3 . The gas-operated firearm of  claim 1  wherein the resilient member is positioned between a sealing ring and either the piston or the wall of the cylinder, and wherein the sealing ring moves with the resilient member as the piston moves. 
   
   
       4 . The gas-operated firearm of  claim 3  wherein the sealing ring is in contact with a surface, and wherein the sealing ring and the surface that is in contact with the sealing ring move relative to each other when the piston moves. 
   
   
       5 . The gas-operated firearm of  claim 1  wherein the resilient member is positioned in a recess in the piston or the wall of the cylinder. 
   
   
       6 . The gas-operated firearm of  claim 5  wherein a sealing ring covers the resilient member in the recess. 
   
   
       7 . The gas-operated firearm of  claim 1  wherein the resilient member is positioned in a recess in the piston and a sealing ring is positioned between the resilient member and the wall of the cylinder. 
   
   
       8 . The gas-operated firearm of  claim 1  wherein the resilient member is positioned in a recess in the wall of the cylinder and a sealing ring is positioned between the resilient member and the piston. 
   
   
       9 . The gas-operated firearm of  claim 1  wherein the piston includes a valve that opens when excessive pressure is in the cylinder, the resilient member being positioned between the valve and the wall of the cylinder. 
   
   
       10 . A gas-operated shotgun comprising:
 an action;   a magazine;   a cylinder that fills with high pressure gas when a cartridge is fired, the magazine forming at least part of the cylinder, the cylinder including a wall;   a piston positioned in the cylinder and configured to move in response to the high pressure gas in the cylinder, the piston supplying force to operate the action of the shotgun; and   a resilient member positioned between the piston and the wall of the cylinder to prevent the high pressure gas from escaping between the piston and the wall of the cylinder, the resilient member being in contact with one or more surfaces;   wherein none of the one or more surfaces and the resilient member move relative to each other when the piston moves.   
   
   
       11 . The gas-operated shotgun of  claim 10  wherein the action is an automatic action. 
   
   
       12 . The gas-operated shotgun of  claim 10  wherein the resilient member is positioned between a sealing ring and either the piston or the wall of the cylinder, and wherein the sealing ring moves with the resilient member as the piston moves. 
   
   
       13 . The gas-operated shotgun of  claim 12  wherein the sealing ring is in contact with a surface, and wherein the sealing ring and the surface that is in contact with the sealing ring move relative to each other when the piston moves. 
   
   
       14 . The gas-operated shotgun of  claim 10  wherein the resilient member is positioned between the piston and the magazine that forms at least part of the cylinder. 
   
   
       15 . The gas-operated shotgun of  claim 10  wherein the resilient member is positioned in a recess in the piston or the wall of the cylinder. 
   
   
       16 . The gas-operated shotgun of  claim 15  wherein a sealing ring covers the resilient member in the recess. 
   
   
       17 . The gas-operated shotgun of  claim 10  wherein the resilient member is positioned in a recess in the piston and a sealing ring is positioned between the resilient member and the wall of the cylinder. 
   
   
       18 . The gas-operated shotgun of  claim 10  wherein the resilient member is positioned in a recess in the wall of the cylinder and a sealing ring is positioned between the resilient member and the piston. 
   
   
       19 . The gas-operated shotgun of  claim 10  wherein the piston includes a valve that opens when excessive pressure is in the cylinder, the resilient member being positioned between the valve and the wall of the cylinder. 
   
   
       20 . A gas-operated shotgun comprising:
 a receiver;   a barrel coupled to the receiver;   a magazine coupled to the receiver and configured to hold shotshells;   a cylinder that fills with high pressure gas when a cartridge is fired, the cylinder having an annular shape and including an interior wall and an exterior wall, the magazine forming at least part of the interior wall;   a bracket that channels the high pressure gas from the barrel to the cylinder, the bracket forming at least part of the exterior wall of the cylinder;   a piston positioned in the cylinder and configured to move in response to the high pressure gas in the cylinder, the piston supplying force to operate an action of the shotgun; and   a resilient member positioned between the piston and either the interior wall of the cylinder or the exterior wall of the cylinder, the resilient member being configured to prevent the high pressure gas from escaping from the cylinder;   wherein the resilient member and any surface that the resilient member is in contact with do not move relative to each other when the piston moves.   
   
   
       21 . The gas-operated shotgun of  claim 20  wherein the action is an automatic action. 
   
   
       22 . The gas-operated shotgun of  claim 20  wherein the resilient member is positioned between the piston and the interior wall of the cylinder. 
   
   
       23 . The gas-operated shotgun of  claim 20  wherein the resilient member is positioned between a sealing ring and either the piston, the interior wall of the cylinder, or the exterior wall of the cylinder, and wherein the sealing ring moves with the resilient member as the piston moves. 
   
   
       24 . The gas-operated shotgun of  claim 23  wherein the sealing ring is in contact with a surface, and wherein the sealing ring and the surface that is in contact with the sealing ring move relative to each other when the piston moves. 
   
   
       25 . The gas-operated shotgun of  claim 23  wherein the resilient member is positioned between the sealing ring and the piston. 
   
   
       26 . The gas-operated shotgun of  claim 23  wherein the resilient member is positioned between the sealing ring and the interior wall of the cylinder. 
   
   
       27 . The gas-operated shotgun of  claim 23  wherein the resilient member is positioned between the sealing ring and the exterior wall of the cylinder. 
   
   
       28 . The gas-operated shotgun of  claim 20  wherein the resilient member is positioned between the piston and the magazine that forms at least part of the cylinder. 
   
   
       29 . The gas-operated shotgun of  claim 20  wherein the resilient member is positioned in a recess in the piston, the interior wall of the cylinder, or the exterior wall of the cylinder. 
   
   
       30 . The gas-operated shotgun of  claim 29  wherein a sealing ring covers the resilient member in the recess. 
   
   
       31 . The gas-operated shotgun of  claim 20  wherein the resilient member is positioned in a recess in the piston and a sealing ring is positioned between the resilient member and either the interior wall of the cylinder or the exterior wall of the cylinder. 
   
   
       32 . The gas-operated shotgun of  claim 20  wherein the resilient member is positioned in a recess in either the interior wall of the cylinder or the exterior wall of the cylinder, and wherein a sealing ring is positioned between the resilient member and the piston. 
   
   
       33 . The gas-operated shotgun of  claim 20  wherein the piston includes a valve that opens when excessive pressure is in the cylinder, the resilient member being positioned between the valve and the interior wall of the cylinder.