Quick-release barrel firearm

Abstract

Firearms with improved systems and methods of attaching the barrels that can provide for quicker and easier replacement of the barrel. In particular embodiments, the attachment mechanism includes a door that opens to release the barrel from the receiver. In certain embodiments, the door is located on the firearm below the barrel, a latch releasably holds the door closed, the door is pivotably attached to the receiver at a first end of the door, the latch is at a second end of the door, the door includes a barrel clamp that contacts a flange at a rearward end of the barrel to secure the barrel to the receiver, a rotating cam in the door secures the barrel to the receiver, the barrel attaches to the receiver without screwing the barrel into the receiver and without screwing an attachment component onto threads on the receiver, or a combination thereof.

What is claimed is: 
     
         1 . A firearm comprising a receiver, a barrel, and an attachment mechanism that attaches the barrel to the receiver, wherein the attachment mechanism comprises a door that opens to release the barrel from the receiver. 
     
     
         2 . The firearm of  claim 1  wherein the door is located on the firearm below the barrel. 
     
     
         3 . The firearm of  claim 1  further comprising a latch that releasably holds the door closed to secure the barrel to the receiver. 
     
     
         4 . The firearm of  claim 3  wherein the latch that releasably holds the door closed to secure the barrel to the receiver requires two separate actions of an operator of the firearm to detach the barrel to avoid inadvertent detachment of the barrel of the firearm. 
     
     
         5 . The firearm of  claim 3  wherein the latch that releasably holds the door closed to secure the barrel to the receiver comprises a sliding safety catch, a first spring that biases the sliding safety catch, a pivoting latch lever that is secured by the sliding safety catch, a sliding door-engagement feature, and a second spring that biases the sliding door-engagement feature, wherein the pivoting latch lever is pivotably attached to the sliding door-engagement feature, and wherein an operator of the firearm detaches the barrel by sliding the sliding safety catch, which releases the pivoting latch lever, and then by sliding the sliding door-engagement feature by applying a force to the pivoting latch lever. 
     
     
         6 . The firearm of  claim 3  wherein: the door has a first end and a second end opposite the first end; the door is pivotably attached to the receiver at the first end; and the latch is located at the second end of the door. 
     
     
         7 . The firearm of  claim 6  wherein the second end of the door is forward of the first end of the door. 
     
     
         8 . The firearm of  claim 1  wherein the door comprises a barrel release cover and a barrel clamp and wherein the barrel clamp comprises a clamping surface that contacts a flange at a rearward end of the barrel to secure the barrel to the receiver. 
     
     
         9 . The firearm of  claim 8  further comprising an adjustment system that provides for adjustment of a location of the barrel clamp relative to the barrel release cover to adjust a clamping force between the clamping surface and the flange at the rearward end of the barrel. 
     
     
         10 . The firearm of  claim 9  wherein: the door has a first end and a second end opposite the first end; the door is pivotably attached to the receiver at the first end; the door is located on the firearm below the barrel; the firearm comprises a latch that releasably holds the door closed to secure the barrel to the receiver; the latch is located at the second end of the door; and the second end of the door is forward of the first end of the door. 
     
     
         11 . The firearm of  claim 9  wherein the adjustment system comprises a clamp adjusting screw that extends through a hole in the barrel release cover into a cavity in the barrel clamp. 
     
     
         12 . The firearm of  claim 11  wherein the adjustment system further comprises an adjusting screw holder that holds the clamp adjusting screw to prevent inadvertent rotation of the clamp adjusting screw. 
     
     
         13 . The firearm of  claim 11  wherein the adjustment system further comprises a clamp adjusting nut located within the cavity in the barrel clamp, wherein the clamp adjusting screw threads into the clamp adjusting nut, and wherein the clamp adjusting nut comprises an inclined nut surface that engages an inclined engagement surface within the cavity in the barrel clamp. 
     
     
         14 . The firearm of any of  claim 1  wherein the barrel attaches to the receiver without screwing the barrel into the receiver and without screwing a lock ring onto the receiver around the barrel. 
     
     
         15 . The firearm of  claim 1  wherein the door comprises a rotating cam that secures the barrel to the receiver. 
     
     
         16 . The firearm of  claim 15  further comprising a spring that biases the cam against the barrel. 
     
     
         17 . The firearm of  claim 16  wherein the cam engages a feature on the barrel. 
     
     
         18 . The firearm of any of  claim 1  wherein the firearm is a rifle configured to fire in a fully-automatic mode and in a semi-automatic mode. 
     
     
         19 . A firearm comprising a receiver, a barrel, and an attachment mechanism that attaches the barrel to the receiver, wherein the attachment mechanism comprises a rotating cam that secures the barrel to the receiver. 
     
     
         20 . A firearm comprising a receiver, a barrel, and an attachment mechanism that attaches the barrel to the receiver, wherein the barrel attaches to the receiver without screwing the barrel into the receiver and without screwing an attachment component onto threads on the receiver such that the attachment component contacts a flange at a rearward end of the barrel to secure the barrel to the receiver.