Abstract: An action rate control system for a gas operated firearm that includes an action sleeve and an action rate control cylinder. The action sleeve moves in a rearward direction in response to a volume of combustion gases that are generated during firing of the firearm and diverted from the barrel of the firearm through gas ports. The action rate control cylinder is connected to the action sleeve by a linkage that controls movement and slowing of the action sleeve as it approaches a rear limit for its movement. The resistance force generated by the rate control cylinder is a function of the velocity of the action sleeve during its movement. In another aspect, a gas operated firearm includes a barrel, a bolt assembly, an action system coupled to the bolt assembly, and a rate control cylinder coupled to the action system. The action system includes a sleeve assembly that is driven by a volume of combustion gases that are diverted from the barrel when a round of ammunition is fired.

Abstract: In a headrest (201) for a vehicle seat, having a support (205), at least one upper and lower linkage (211, 215) hinged to the support (205), which are pivotable around horizontal axles (207, 217), an impact element (213) hinged to the linkages (211, 215), which forms at least one four-bar linkage (219) with the linkages (211, 215) and the support (205), and an energy storage, the energy storage driving the four-bar linkage (219) in the event of a crash, so that the impact element (213) is driven out forwardly from an initial position into a crash position that is locked rearward by a crash lock, a drive (271) is provided by way of which, in normal use, the headrest (201) can be brought from its initial position to at least one other comfort position.