RELATED APPLICATION

This non-provisional patent application claims the priority benefit of Czech Patent Application Serial No. PV2019-696 entitled “Automatic Action Assembly of a Firearm,” filed Nov. 12, 2019, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to an automatic action assembly of a firearm comprising a sliding cartridge chamber arranged in a sliding way between the front and rear dead center.

BACKGROUND

Drives of the automatic function of a firearm are known that utilize the shot impulse, impulse of dust gases harvested from the barrel, drive by the pushing force of the bullet, mixed drives and drives with an external energy source. Breeches driven by harvested gases are mostly locked and are used for weapons of larger gauges. Dynamic breeches, driven by the shot force, called blowback systems, are not locked or braked in most cases and are used for lower power weapons.

With regard to high pressures of combustion gases in the barrel, a simple dynamic breech cannot be used in firearms with a powerful gauge as 5.56×45 mm or 7.62×39 mm. A breech would be able to hold combustion gases in the barrel for a sufficiently long time for the bullet to leave the barrel in case of a high weight of the breech only. Therefore, locking is used for these breeches that must be controlled by a different mechanism from mere action of the shot pressure upon the bullet bottom. Therefore, harvesting of dust gases from the barrel is extensively used in this case. Instead of combustion gas harvesting, breech braking is used, which is sensitive to production accuracy and is prone to system clogging, excessive wear and cartridge deformation.

From the document U.S. Pat. No. 4,069,607A of the applicant JUREK JULIUS V, the principle of a slidable cartridge chamber is known. However, this chamber only serves as an adapter for shooting ammunition of the .22 LR gauge, does not allow locking of the system and imparts rotation to the bullet.

The document U.S. Pat. No. 2,052,287 of the applicant SIG SCHWEIZ INDUSTRIEGES discloses a drive principle based on a short oscillation of the breech parts wherein an impulse is sent to the breech to unlock the system. However, this drive uses locking in the firearm case, is used for low power ammunition and does not have a floating chamber with locking to prevent cartridge deformation.

Therefore, it is the object of the invention to provide such an automatic action assembly of a firearm that would not feature the above-mentioned shortcomings of the prior art.

SUMMARY

The said object is achieved through an automatic action assembly of a firearm comprising a barrel with a sliding cartridge chamber, arranged in a sliding manner between the front and rear dead center, according to the invention the principle of which is that the movement of the sliding chamber is delimited by at least one first stop on the sliding chamber and a corresponding at least one second stop connected to the barrel wherein between the first stop and second stop there is a play A. In the rear part of the sliding chamber, a breech block is lockably connected at the end of which a breech block carrier is seated in a sliding way. The breech block carrier is pushed towards the barrel by a return spring. The breech block is equipped with an unlocking mechanism for delayed disconnection of the breech block from the sliding chamber.

An advantage of the assembly according to the invention is a free fit of the barrel and a consequent enhancement of shooting accuracy wherein a free fit is accompanied by minimal oscillation of the barrel. The assembly of this invention also eliminates the harvesting channel in the barrel, which is a problematic point from the service life point of view. Another benefit of the assembly according to the invention is a lower necessary installation size of the weapon thanks to the absence of a piston assembly.

Unlike known solutions using a sliding chamber, the inventive solution is to innovative in using the sliding chamber to lock the barrel and a breech with the possibility of using the conventional manner of locking consisting in a rotary breech block, a tilting bar and similar locking method.

An advantage of the assembly according to the invention as compared to other systems using “hesitation locking” is that the functional play of the drive is transferred onto the floating chamber, which makes it protected from the action of external influences as sand, dust, mud and other negative impacts.

Another clear advantage is a weight reduction of the entire system as compared to the common piston systems and braked dynamic breeches.

In a preferred embodiment, the distance between the front and rear dead center is adjustable by resetting the position of the front dead center of the sliding chamber, e.g. by turning a control collar arranged between the sliding chamber and the barrel wherein the height of the control collar is variable along its perimeter.

In a preferred embodiment, the position of the control collar is fixed with a locking lever.

Preferably, claws are arranged along the perimeter of the breech block and corresponding protrusions are arranged in the sliding chamber in such a way that the gaps between the protrusions make it possible to axially withdraw the breech block from the sliding chamber after its partial rotation.

In another preferred embodiment, multiple first stops are arranged spokewise along the perimeter of the sliding chamber, and multiple spokewise arranged second stops are connected to the barrel in such a way that the gaps between the second stops make it possible to axially withdraw the sliding chamber from the barrel after its partial rotation.

