×

Gas piston operated upper receiver system

  • US 9,032,860 B2
  • Filed: 12/17/2013
  • Issued: 05/19/2015
  • Est. Priority Date: 12/17/2012
  • Status: Active Grant
First Claim
Patent Images

1. An upper receiver assembly for use with an AR15-type lower receiver in which the lower receiver attaches to an upper receiver assembly by way of a forward pivot pin and a rearward takedown pin, comprising:

  • a monolithic upper receiver and forearm housing configured for operable mating engagement with a lower receiver assembly, the upper receiver and forearm housing including a first lug for connection to the lower receiver using the takedown pin;

    a barrel having a breech end, a muzzle end, and a bore axis;

    a barrel trunnion at the breech end having a second lug for direct connection to the lower receiver using the pivot pin;

    a gas block positioned on the barrel;

    a bolt carrier assembly including a longitudinal slot and rail engagement with the upper receiver assembly on which the bolt carrier assembly slidably reciprocates;

    a long-stroke gas-piston actuation system having a longitudinal axis parallel to and offset from the bore axis, the gas actuation system including a gas tube extending rearwardly from the gas block and a piston extending forwardly from the bolt carrier assembly; and

    a recoil spring assembly housed within the monolithic upper receiver and forearm housing and extending coaxially with the longitudinal axis of the gas-piston actuation assembly,wherein the barrel trunnion is configured for engagement with the upper receiver and forearm housing with longitudinal keyway features, one of a keyway or engagement rail being on the barrel trunnion and the other on the upper receiver and forearm housing; and

    wherein the gas block is configured for engagement with the upper receiver and forearm housing with longitudinal keyway features, one of a keyway or engagement rail being on the gas block and the other on the upper receiver and forearm housing.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×