| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 089191020 | Annular piston | 6 |
| 20100282065 | GAS SYSTEM FOR FIREARMS - A piston assembly is provided for a gas-operated firearm of the type having a chamber and a barrel. The piston assembly includes a gas expansion housing and a piston mounted within the gas expansion housing. An annular recess is formed in the outer wall of the piston to receive exhaust gases diverted from the barrel upon firing of the firearm. At least one longitudinally extending groove extends from the annual recess to the head of the piston and forms a pathway for diverting the exhaust gases to the head of the piston. During firing, pressurized gases are diverted into the annular recess and expand longitudinally from the annular recess to the piston head, whereupon the pressurized exhaust gas drives the gas piston rearwardly along the housing. | 11-11-2010 |
| 20100326266 | Gun Barrel Assembly - A firearm barrel assembly having a gun barrel with a muzzle opening on a distal end, a shroud coaxially surrounding at least a portion of the barrel, the shroud having a distal portion extending beyond the muzzle opening defining a shroud front region having a distal end portion, a proximal portion extending proximally from the muzzle opening defining an annular region between the barrel and shroud, the shroud front region and annular region in fluid communication with substantially no obstruction between the shroud front region and the annular region, and a front wall disposed at the distal end portion of the shroud. The wall has an opening to allow passage of a projectile fired from the firearm. | 12-30-2010 |
| 20120137871 | CONCENTRIC CYLINDER GAS AUTOMATED FIREARM - A fixed-barrel, gas-operated firearm having its barrel concentrically mounted within a pressure tube enclosing substantially all of the moving parts of the firearm's action. A gas cup reciprocates under the influence of propellant gas pressure when the firearm is fired, driving slide members that link the pressure cup to the firearm's bolt rearward within the pressure tube, unlocking the breech, rotating and retracting the bolt, discharging the spent cartridge casing and then advancing the bolt to chamber a new cartridge. | 06-07-2012 |
| 20130291713 | Annular Piston System for Rifles - An annular piston system for a firearm comprises a barrel, a gas block assembly, a piston, and a spring. The barrel has multiple sections lengthwise, one of the sections having at least one gas port hole to vent gas from the barrel. The gas block assembly is disposed annularly around the barrel and is adjustable to control an amount of gas flowing out of the barrel through the at least one gas port hole. The piston is disposed annularly around the barrel and can move longitudinally along the barrel in response to being pushed by the gas flowing out of the barrel. The spring is disposed annularly around the third section of the barrel and coupled to the piston. The spring limits a distance that the piston can move longitudinally along the barrel when the piston is pushed to move by the gas flowing out of the barrel. | 11-07-2013 |
| 20140331853 | Firearm Action and Gas System - A rifle in a bullpup configuration is provided, comprising a receiver having a trigger assembly and a magazine well, and a barrel having a barrel extension attached to the receiver. A gas assist system is attached to the barrel, including a gas housing surrounding the barrel and having an annular expansion chamber, and an annular gas piston slidably disposed within the gas housing. A thrust block is in contact with the gas piston, wherein the thrust block is slidably disposed along one or more action guide members. A rigid slide member extends from the thrust block and behind the trigger assembly. A bolt carrier and bolt are attached to the second end of the slide member and slidably disposed along one or more bolt guide members. The rifle further includes a linear hammer slidably disposed along one or more hammer guide members, and a sear assembly within the receiver having a sear member to retain the hammer, and a disconnector in communication with the sear member to release the hammer upon actuation of the trigger assembly. | 11-13-2014 |
| 20150082978 | CONCENTRIC CYLINDER GAS-OPERATED AUTOMATIC FIREARM - A fixed-barrel, gas-operated firearm having its barrel concentrically mounted within a pressure tube enclosing substantially all of the moving parts of the firearm's action. A gas cup reciprocates under the influence of propellant gas pressure when the firearm is fired, driving slide members that link the pressure cup to the firearm's bolt rearward within the pressure tube, unlocking the breech, rotating and retracting the bolt, discharging the spent cartridge casing and then advancing the bolt to chamber a new cartridge. | 03-26-2015 |
