Abstract: The mechanism comprises a main frame (1) and its extension (1?), which accommodate a barrel (21) with fixed mounting, a mobile bolt (22) and its guiding pin ensemble (66) and main spring (67) moving in the main frame (1), a mobile mass (34) and its assembly of guiding pin (60), push plate (61) and return spring (62), and a mobile mass catch sear (42) and its spring (7). The mobile mass pivots from a first position under the barrel to a downward position in reaction to the backward movement of the mobile bolt. The placement of the mobile mass in front of the chamber directs counteracting forces down on the barrel to prevent muzzle climb during operation.

Abstract: An automatic firearm that includes a unitary portion including a human interface and a barrel defining a longitudinal dimension. A slidable portion is attached to the unitary portion so as to permit the slidable portion to slide in the longitudinal dimension. The slidable portion includes at least a portion of a firing chamber. In addition, a lock is adapted to selectably fix the slidable portion relative to the unitary portion. Also, a chamber attached to the unitary portion and an inertial member permitted to move inside the chamber and urged into a first position, the inertial member adapted to translate into a second position, displaced from said first position by at least 0.1 cm, upon firing of the firearm, in which second position the inertial member begins to change the position of the lock, thereby permitting the moveable portion to move relative to the unitary portion.

Abstract: A lightweight grenade launcher utilizing a rotary feed mechanism in conjunction with a toggle link bolt movement mechanism to incorporate the barrel, flash suppressor, bolt and toggle link mechanism as part of the gun's recoiling mass with the barrel moving during recoil and counter recoil through a center aperture in the rotary sprocket of the feed mechanism.

Abstract: A pistol in which a recoil-impacted bolt is in engagement with the front link of a toggle; and such link carries a transmittance pin designed to be struck by the hammer of the pistol when the links of the toggle are aligned. The bolt carries a firing pin advanced by the transmittance pin when the pistol is fired. The motion of recoil is transmitted from the bolt to the barrel through the toggle; and such motion later buckles the toggle by means of a supporting link attached to a rear toggle link and to a pistol frame. Also, in the event of recoil, the rear of the barrel structure has a spacer which impinges on the hammer, driving it to a rearward cocked position.

Abstract: In a Luger pistol equipped with a toggle hold open mechanism, a small portion of one of the frame side rails is milled out in the vicinity of the sear bar slide to receive a new L-shaped release lever engageable at one end with the gun's hold open latch. The original sear bar slide is replaced by a modified form engageable with both the thumb safety lever and with the release lever in such manner that as the safety lever is moved to "safe" position, the release lever disengages the hold open latch from the breech block and allows the toggle mechanism to move forwardly and downwardly into closed position. Concurrently, the trigger mechanism is automatically locked against firing.