Blowback-type firing unit

Abstract

A self-contained blowback-type firing unit insertable as a discrete subassembly in a gun body is disclosed. The subassembly may further comprise a barrel comprising a forward muzzle, a rearward open breech and a rearward spring abutment, a compression spring parallel to the barrel with a rearward end portion abutting the rearward spring abutment, and a bolt parallel to the spring and barrel, where the bolt comprises a firing pin that is moveable independently of the bolt.

What is claimed is: 
     
         1 . A blowback-type firing unit insertable as a discrete subassembly in a gun body, comprising
 a barrel comprising a forward muzzle and a rearward open breech and a rearward spring abutment;   a compression spring parallel to the barrel with a rearward end portion abutting the rearward spring abutment; and   a bolt parallel to the spring and barrel, where the bolt comprises a firing pin that is moveable independently of the bolt;   wherein the blowback-type firing unit insertable as a discrete subassembly in the gun body is self-contained.   
     
     
         2 . A firing unit according to  claim 1 , wherein the firing pin is located in a counter bore of the bolt. 
     
     
         3 . A firing unit according to  claim 1 , wherein the firing pin is retractable. 
     
     
         4 . A firing unit according to  claim 1 , wherein the firing pin is spring loaded. 
     
     
         5 . A firing unit according to  claim 1 , wherein the bolt further comprises a firing pin anvil. 
     
     
         6 . A firing unit according to  claim 1 , wherein the subassembly comprises a barrel, a bolt, and a compression spring, where the subassembly may be completely removed from the gun body without disassembling the member parts of the subassembly. 
     
     
         7 . A firing unit according to  claim 1 , wherein the bolt can move forward against the barrel without discharge of the firing unit. 
     
     
         8 . A firing unit according to  claim 1 , wherein the bolt and barrel are in longitudinal slideable engagement. 
     
     
         9 . A firing unit according to  claim 1 , wherein the bolt comprises a forward spring abutment against which a forward end portion of the spring abuts and a firing pin base axially rearwardly of the barrel with apertures defined between the forward spring abutment and the firing pin base permit entry and ejection of successive cartridges relative to the barrel breech. 
     
     
         10 . A firing unit according to  claim 1 , wherein the barrel is inserted laterally into the bolt, the compression spring is telescoped around the barrel so that the rearward end of the compression spring is abutted by a rearward spring abutment on the barrel. 
     
     
         11 . A firing unit according to  claim 1 , further comprising a quick connection of a forward annular element by means of a bayonet attachment. 
     
     
         12 . In a self-contained blowback-type firing unit insertable as a discrete subassembly in a gun body, which includes a barrel with a forward muzzle and a rearward open breech and a rearward spring abutment, and which includes a compression spring parallel to the barrel with a rearward end portion abutting the rearward spring abutment, and which further includes a reciprocable bolt parallel to the spring and barrel, the bolt comprising a forward spring abutment against which a forward end portion of the spring abuts, the bolt and barrel being in longitudinal slideable engagement, the improvement which comprises
 where a firing pin is movable within the bolt.   
     
     
         13 . A firing unit according to  claim 12 , wherein the bolt can accept a non-fixed firing pin. 
     
     
         14 . A firing unit according to  claim 12 , wherein the bolt is spring loaded with a pin retainer. 
     
     
         15 . A firing unit according to  claim 12 , wherein the bolt further comprises a retractable firing pin. 
     
     
         16 . A firing unit according to  claim 12 , wherein the firing pin is spring loaded. 
     
     
         17 . A firing unit according to  claim 12 , wherein the bolt further comprises a firing pin anvil. 
     
     
         18 . A firing unit according to  claim 12 , wherein the bolt can move forward against the barrel without discharge of the firing unit. 
     
     
         19 . A firing unit according to  claim 12 , further comprising matching slideably engaged longitudinal track surfaces on the barrel and bolt respectively defined by radially extending tongue means on one of the barrel and bolt and slot means on the other of the barrel and bolt and which prevent rotation of the bolt on the barrel, the barrel track surfaces being limited to a location rearwardly of the rearward end portion of the spring. 
     
     
         20 . A firearm, comprising:
 a self-contained blowback-type firing unit insertable as a discrete subassembly in a gun body, comprising:
 a barrel comprising a forward muzzle and a rearward open breech and a rearward spring abutment; 
 a compression spring parallel to the barrel with a rearward end portion abutting the rearward spring abutment; and 
 a bolt parallel to the spring and barrel, where the bolt comprises a bore containing a spring loaded firing pin.