Lightweight machine gun receiver and method of manufacturing

A receiver for use in the manufacture of a lightweight and strong machine-gun comprising a left shell that includes a milled, single-piece metal flat body of a predefined peripheral shape that is substantially rectangular, and a right shell including a milled, single-piece metal flat body, including said right shell formed in size and shape to be joined together symmetrically with said left shell, to form a compartment, said left shell and said right shell including the same size and shape dovetail interlocking joints, milled in said left shell and said right shell at the same locations, said left shell joined to said right shell solely by dovetail fasteners, without welding, without rivets, and without nuts and bolts, forming a rigid, strong, lightweight machine-gun receiver. First and second takedown pins are also used to fasten the left shell to the right shell after the left and right shells have been interlocked together by the dovetail interlocking joints to prevent vertical movement between the left shell and the right shell.

BACKGROUND OF THE INVENTION

1. Field of the Invention

A lightweight machine-gun receiver and the method of manufacturing comprising a machine-gun left shell, constructed from an elongated, milled, flat single-piece of metal, and a machine gun right shell, constructed from an elongated, milled, single-piece of metal, said left shell having a plurality of dovetail interlocking joints, said right shell having a plurality of complementary dovetail interlocking joints, said left shell and said right shell firmly fastened together by said left shell and said right shell dovetail interlocking joints, eliminating welding and rivets, providing an exceptionally strong, very lightweight machine-gun receiver.

2. Description of Related Art

Traditional belt-fed machine guns have been manufactured from inexpensive carbon steel. A typical machine-gun includes a plurality of individual parts that make up the receiver. The machine-gun receiver parts are fastened together by rivets and welding, resulting in a very heavy, expensive to manufacture and assemble, machine-gun.

An example of a traditional machine-gun would be the model M 240. Because of its extreme weight, the M 240 firearm was and is often carried with difficulty by the war fighter. The M 240 machine-gun length is relatively long and cumbersome for implementation on a battlefield as an assault weapon. The M 240 receiver chamber may include up to 19 separate metal elements, affixed into the receiver chamber.

The manufacture of a machine-gun receiver with numerous individual, different parts increases the overall cost of manufacturing, and the weight of the receiver itself.

The improved lightweight machine-gun and method of manufacture described herein, and in particular, the improved receiver and its manufacture, can reduce by as much as one-third the length of a conventional light infantry machine-gun, such as the M 240, and can reduce the weight of the overall machine-gun by as much as one third. This greatly improves the war fighter portability and manipulation of a light machine-gun, increasing fire capability as well as reliability.

The improved invention described herein discloses a weapon receiver, formed from a left shell and a right shell, each shell milled from a single sheet of metal, to integrate up to 19 separate metal elements within the receiver chamber, Also, in the invention described herein, forming the left shell and the right shell, each shell from a milled, flat, single-piece of metal, allows the left shell and right shell wall structures to be varied, in thickness at strategic locations, to permit reductions in the overall weight of each shell, while at the same time increasing each shell's overall strength, without diminishing the firing action of the machine-gun in any way.

Published firearm disclosures describe guns, both toy and real, typically as having left and right frames, left and right housings, and left and right shells, that all use rivets and welding for joining and connecting these left and right gun components, forming firearm receivers.

Applicants have found that the strongest and best way to firmly connect the left shell and the right shell together, especially in manufacturing a lightweight machine-gun that has a superior housing to withstand the forces required in the operational machine-gun, are best constructed using an elongated, flat, milled single-piece of metal for each shell, each shell (left and right) constructed having inside receiver surfaces and portions of its perimeter milled with a plurality of dovetail inter-lockable joints, for rigidly connecting the left shell and the right shell together in the construction of a machine-gun, greatly reducing weight and length of the machine-gun and cost of manufacturing, while increasing efficiency in the manufacturing process.

SUMMARY OF THE INVENTION

A receiver for a firearm comprising a left shell and a right shell, each formed from an elongated, substantially flat, milled, single-piece of metal. The left shell and the right shell are firmly connected together by a plurality of dovetail inter-lockable joints, located at strategic corresponding locations on the left shell and the right shell.

The left shell and the right shell, each include an elongated, substantially flat, plate receiver inside wall surface, and a unitary bottom horizontal wall. The left shell and the right shell each have upper and lower horizontal dovetail interlocking joints, protruding perpendicularly inwardly from the left shell receiver inside wall surface and the right shell receiver inside wall surface. The left and right shell dovetail interlocking joints provide a vertical joint connection together. A dovetail joint is formed by one or more tapered projections (tenons) on one piece which interlock with corresponding notches or recesses (mortises) in another piece. The dovetail tenons and mortises are sized for mutual engagement with each other, for firmly connecting the left shell to the right shell with the dovetail interlocking joints, eliminating the need for joining the left shell to the right shell with rivets, welding, or fastening bolts and nuts. A pair of takedown pins are used to connect the right shell and the left shell together, to prevent vertical movement or separation of the left shell relative to the right shell within the dovetail interlocking joints.

The two-piece receiver is formed by joining the left shell and the right shell together to form a chamber by manually engaging the dovetail interlocking joints on the left shell with the corresponding ones on the right shell. Each shell is made of a flat, single, rectangular plate of metal. The left shell and the right shell have outside receiver surfaces and inside receiver surfaces. The inside receiver surface of each shell has a plurality of milled machine projections at precise locations that, when the left and right shells are joined, act as a receiver and function to engage essential components of the machine-gun that are housed inside the receiver chamber, including the bolt and operating rod assemblies, and attached or connected to the receiver including a threaded barrel assembly, a trigger assembly, and a butt stock. The inside receiver surface of the left shell has a similar, but not identical, array of milled protrusions that function with similar milled protrusion operating elements on the inside receiver surface of the right shell. The inside surface protrusions for the left and right shells are precision machined during manufacturing for maximum cooperation with the corresponding protruding elements for the essential proper connection of the threaded barrel assembly to a threaded barrel assembly locking interface and housing of the gas tube assembly that also include dovetail interlocking joints to connect the left shell in the right shell. The shape and function of the left shell milled protruding inwardly elements are not identical to the construction of the right shell milled protruding inwardly elements, but are designed to complement each other and securely connect the threaded barrel assembly and house the gas tube assembly when the left shell is physically connected to the right shell, as well as guide the action of the bolt and operating rod assemblies. For example, left shell right shell each have milled inwardly protruding elements to form the threaded barrel assembly locking interface, when joined that connects a threaded barrel assembly to the receiver.

The dovetail interlocking joints that connect together the left shell and the right shell, provide excellent tensile strength for holding the left and right shells together, withstanding the shearing forces on the overall receiver when the machine-gun is fired or subjected to other external forces. A dovetail joint includes tapered projections (tenons) on one piece that interlock with corresponding notches (recesses or mortises) on another dovetail joint piece, to form a very strong interlock. Each tapered dovetail tenon is typically wider at its extremity than at its base.

One definition of a dovetail joint includes a flaring tenon and mortise into which it fits tightly, making an interlock joint that resists pulling apart in all directions except one.

Several different top and bottom left shell and right shell peripheral and receiver inside horizontally inwardly facing areas, can be formed and milled. The dovetail joints interlock the left shell and the right shell by manual vertical movement and connection of the left shell with the right shell at precise corresponding locations, so that the left shell can be firmly joined to the right shell in a plurality of dovetail interlocking joints. The peripheral areas with the dovetail to locking joint facing inwardly on the left shell and the right shell preferably will be along the top surface of each shell and in designated areas of the bottom surface of each shell.

In the construction of a machine-gun using the invention, the left shell and the right shell are milled individually with the appropriate number of corresponding related dovetail joints at predesignated corresponding inside surface protrusions and peripheral locations. Once formed, the left shell and the right shell are then connected together, initially to form the machine-gun receiver, before any components, such as the operating rod assembly, bolt assembly, and the gas tube of the machine-gun, are housed in the chamber formed by the left and right shells.

The machine-gun components necessary to be housed in the receiver chamber include the threaded barrel assembly, securely connected in front to the milled threaded barrel assembly locking interface, the gas tube assembly, the bolt assembly, and operating rod assembly. The buttstock is removably attached to the rear end face of the receiver.

A detailed description of a complete machine-gun is not required to fully disclose the present invention. The machine-gun receiver, described herein, is sufficient as described to be used to manufacture an improved lighter weight, stronger machine-gun, having less individual parts, at a greatly reduced expense. The firearm receiver described herein is capable of housing, securely connecting or and guiding the action of attaching all of the necessary, essential components of a machine-gun such as a M 240 MC, using existing off-the-shelf machine-gun components that include the threaded barrel assembly, bolt assembly, the operating rod assembly, and exhaust tube, housed in the front forward end of the receiver described herein, once the left shell and right shell have been interlock together by dovetail joints. The receiver described herein also includes a rear, vertical section that includes connectors to attach the buttstock plate removably to the end of the receiver. The receiver is sized and constructed to receive a conventional trigger assembly for a machine-gun. The receiver includes sized and shaped openings of the proper chamber areas to receive mechanisms that provide for the feeding and ejection of ammunition in a high-speed manner.

Advantages of milling left and right receiver shells include having an integrated rear site formed on the receiver top with the receiver dovetail connectors; ambidextrous charging handle slots, left and right sides, for the ambidextrous use of the charging handle on either side of the receiver; and a threaded barrel assembly locking interface, provided by the left shell and the right shell together, for housing a threaded barrel assembly. The receiver also includes left and right jam studs, one positioned on each side of the outside surface of the left shell and the right shell for a warrior pivoting the weapon at a vertical edge opening.

Another advantage of milling left and right receiver shells is the formation of integrated milled guide rails, substantially horizontal, on the inside receiver shell surfaces to guide the action of internal moving assemblies in the receiver. This reduces the manufacturing complexity of individual parts that must be fastened in position inside the receiver to the left and right shells, reduces weight, and reduces costs of production.

It is an object of this invention to provide a machine-gun receiver that houses certain machine-gun components resulting in an improved light weight machine-gun that can be safely and effectively manipulated by a single warrior. The light weight machine-gun is made possible using a lightweight receiver made up of a milled, single-piece metal left shell and a milled, single-piece metal right shell, firmly interlocked together in critical areas by a plurality of dovetail joints, at strategic locations on the left shell and the right shell.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, specificallyFIG.1, a representative machine-gun made in accordance with the present invention, is shown including a receiver10that includes left receiver shell12interlocked to right receiver shell14by a plurality of dovetail interlocking joints12aon the milled top periphery (a section of the integrated, self-contained threaded barrel assembly locking interface housing) of left shell12joined to dovetail interlocking joints14aon the milled top periphery (a section of the integrated, self-contained threaded barrel assembly locking interface housing) of the right shell14.

The machine-gun shown inFIG.1includes a threaded barrel assembly16(that is securely connected to a threaded barrel assembly locking interface12fin receiver10at and below the dovetail interlocking joints12aand14a), a gas tube18, also housed in the chamber formed by receiver10, a pistol/trigger assembly20attached to the bottom of receiver10, and a buttstock22attached to the rear end of receiver10. The machine-gun also includes a belt opening24that receives bands of ammunition.

FIG.1shows a rear gun sight36, formed by joining the left shell12to the right shell14with dovetail joints. Also shown inFIG.1is a jam stud40protruding outwardly from the exterior surface of left shell12. A similar jam stud is located on right shell14. The jam studs are designed to position the weapon, pressed against a vertical edge surface, to hold the weapon firmly in place, allowing the warrior to pivot the weapon.

The machine-gun shown inFIG.1is very lightweight and reduced in length compared to a conventional M 240 machine-gun. The receiver10however, as shown interlocked by a plurality of dovetails joints without any welding can be used across platforms to other machine gun weapons systems.

The left shell12and the right shell14also include various rib portions12bthat are thicker than the panel12dnext to the rib portions12b, to reduce weight and increase the strength of the left shell12. The left shell also includes areas of open passages or apertures12cthat allow the threaded barrel assembly16to cool so that air can flow through passages12cfor cooling.

The machine-gun, shown inFIG.1, includes the invention and has a plurality of dovetail interlocking joints, many of which are described below.

FIG.2shows a front elevational view of the machine-gun shown inFIG.1. Also shown inFIG.2is left shell12and right shell14interlocked together forming receiver10. The trigger housing assembly20is also shown as is threaded barrel assembly16and gas tube18.FIG.2also shows jam stud40and jam stud42mounted near the front of the weapon receiver. Slot44shows the ambidextrous charging handle slot available in the left shell of the receiver. A similar charging handle slot is provided on the opposite side of the weapon in the right shell, allowing for ambidextrous positioning of the charging handle.

FIG.3shows a left elevational view of a machine-gun that includes the receiver10and left shell12. The threaded barrel assembly16is securely connected in milled protruding elements formed on the inside surfaces of left shell12shown and right shell14joined thereto, that allows the threaded barrel to be securely connected in the receiver10. The gas tube assembly18is also housed in receiver10firmly.FIG.3shows a trigger housing assembly20connected to the receiver10. The buttstock22is also removably attached to the rear end face of the receiver10. A feed tray assembly24is mounted at the top portion of receiver10and serves as a guide for positioning cartridges to assist in chambering.FIG.3illustrates the rear gun sight36and jam stud40. Aperture28and aperture32receive takeaway pins shown inFIGS.13A and13Bto secure the receiver.

FIG.4shows a rear elevational view including buttstock22and trigger housing assembly20. Also shown are the rear gun sight36, jam stud40, and jam stud42.

FIG.5shows a right side elevational view of the machine-gun shown inFIG.1. Receiver10includes right shell14that is very similar in an exterior appearance to left shell12(not shown). For example, right shell14includes exterior surface areas14dthat are not as thick as ribs14bthat are thicker than surface areas14b. An open aperture or hole14callows air and heat to pass through from barrel16for cooling. The thickness of right shell14varies as a plurality of ribs14bthat are thicker than the surface areas14band are specifically designed to strengthen the entire shell10, while at the same time reducing weight throughout the shell10, to make the machine-gun lighter in weight, without sacrificing strength.

FIG.5discloses elongated slot46which is provided for using a charging handle on the right side of the weapon, making a similar elongated slot44on the left side of the weapon ambidextrous for the use of a charging handle, on either side of the weapon. The rear gun sight36and the front gun sight38are shown. A jam stud42is shown mounted at the front end of right shell14.

FIG.6shows a top plan view of the machine-gun shown inFIG.1. Receiver10is formed by left shell12and right shell14. The threaded barrel assembly16is housed in threaded barrel assembly locking interface in receiver10. The buttstock22is removably attached to the rear end face of receiver10. Rear gun sight36, jam stud40, and jam stud42are shown.

FIG.7is a bottom plan view the machine-gun shown inFIG.1. The receiver10is shown including left shell12and right shell14firmly interlocked together by a plurality of dovetail joints12aand14aalong the bottom peripheries of left shell12and right shell14. In the receiver10shown inFIG.7, there are no welds connecting the right shell12to left shell14, only dovetail interlocking joints shown at12aand14a. A gas tube assembly18is housed in receiver10and a threaded barrel assembly16securely connected. The buttstock22is attached to the rear of receiver10.

FIG.8shows an exploded right perspective view of the machine-gun shown inFIG.1. The left shell12is shown separated from the right shell14in the exploded view. The inside surface of left shell12exhibits a plurality of dovetail joints12adistributed along areas of the top and bottom peripheries of left shell12and some in an upper portion on the inside of left shell12, and dovetail joints at the very top of left shell12, around a protruding half-curved milled segment that connects the threaded barrel assembly16to the receiver10having a self-contained threaded barrel locking receptor12ffor barrel16to properly seat into place and lock down securely, when assembled. The gas tube18is housed within the receiver10formed by joining left shell12to right shell14protruding half curved milled segments that also include dovetail joints12aadescribed herein. The buttstock22is connected to the rear portion of the receiver10formed by left shell12and right shell14.

The importance ofFIG.8is to show that the receiver10that is formed by left shell12and right shell14have milled, projecting internal elements that house and lock securely the threaded barrel assembly16to the threaded barrel assembly locking interface12fleft shell segment when joined to the right shell and the gas tube18, without any welding or bolts and nuts or rivets. The receiver10having a left shell12, milled from a single-piece of metal, and a right shell14, milled from a single-piece of metal, together can form a machine-gun receiver10, shown inFIG.1, housing, securing, and guiding essential components, including the barrel assembly16and gas tube18and bolt and operating rod assembly18a, and also attach the trigger assembly20and buttstock22. The assemblage of all the critical components of the machine-gun is accomplished by using a plurality of upper, lower, and middle dovetail interlocking joints,12a,12aa, and14aforming the invention. The left shell12interior wall shows integrated guide rails and channels that can guide the action of internal moving assemblies.

FIG.9andFIG.10show perspective views of the machine-gun receiver10. Takeaway pin aperture's28,30,32are also shown.

FIG.9shows a perspective exploded view of the receiver10having the left shell12separated from the right shell14. The right shell14has a plurality of dovetail interlocking joints14adistributed along the upper periphery of the right shell14near the rear of the receiver10and a midportion of the receiver10. Additionally dovetail interlocking joints are shown on the forward bottom periphery of the right shell14. On the inside surface of the left shell12, there are a plurality of dovetail interlocking joints corresponding exactly with the dovetail joints14aashown on the inside surface of the right shell14, such that the dovetail joints are sized and positioned to allow the left shell12to be firmly and completely connected to the right shell14, eliminating welding, riveting, and bolting together to form a receiver10for a machine-gun as shown inFIG.1. Note that the right shell14includes, on its inside surface, protruding, a milled semi-curved segment that houses the gas tube (not shown) and includes dovetail joints14aa, that are interlocked with a series of corresponding dovetail joints to house a gas tube; milled and protruding from the inside surface wall of the left shell12. Also the right shell14includes an upper half element that includes dovetail joints14abthat connect the threaded barrel assembly16to the machine-gun when interlocked to the right shell12upper barrel receiving element that has dovetail joint fasteners12abthat allow the entire receiver10to be firmly interlocked together by the numerous dovetail joint s described herein. The threaded barrel assembly16is connected to, and the gas tube assembly18and operating rod18aare housed in the receiver10by a plurality of inside shell wall surface areas, milled out of single-piece of metal, forming left shell12and right shell14, making the manufacture of the receiver10extremely efficient. With respect to automation on different models of machine guns using a receiver similar to receiver10, formed in the invention, manufacture will require different inside wall protruding-shaped surfaces on each left shell12and right shell14in order to connect, house, and guide the components of the machine-gun such as the barrel, operating rod, and gas tube assemblies into the receiver10.

FIG.10shows the machine-gun receiver10. The left shell12is firmly interlocked to the right shell14exclusively by a plurality of dovetail interlocking joints14a,14aa, and14abengaged with dovetail joints12a,12aa, and12ab. The receiver10is constructed without any welds, any rivets, or any nuts and bolts fastened together. The left shell12is formed from a single piece of metal, that is milled, which can be accomplished using computer-aided machining, that can operate 24 hours a day. Likewise, the right shell14is milled from a single piece of metal that can be formed using a computer-aided machining factory system run 24 hours a day, with minimal human intervention, greatly reducing the cost of manufacturing, construction and production, as well as, reducing the weight of the final machine gun receiver10. Also milled outer areas12bare thinner than the rib portions12dat strategic locations, for reductions in weight to the overall receiver10, as well as engineered against shearing and other forces.

FIG.11shows an exploded view in a left perspective view of a buttstock22that can be removably attached to the receiver10shown inFIGS.1through10above. The buttstock fastener22fincludes fastening elements22gthat allow the buttstock to be removably attached to the rear end of the receiver10. The main stock22of buttstock22is shown that has a hollow interior portion to receive the buttstock fastener22fat one end. A shock of force absorbing element22bfits at the other end with attaching bolt22cfor holding the force absorber22bto the main stock portion22a. A shoulder engaging pad22dis fixed to the shock absorbing plate22bby fasteners22e. The buttstock22provides comfortable, firm extension when attached to the machine-gun receiver10for absorbing the shock of firing the machine-gun against one's shoulder. The buttstock22is also lightweight but extremely strong and can be detached from the machine-gun via the receiver10.

FIG.12shows an example of a dovetail joint formed with shell12and shell14that can be utilized in the present invention, showing a dovetail joint tenon element14eengaged with a dovetail joint recess, mortise element12einterlocked and that are formed from a portion of the right shell14periphery and internal spaces for creating the dovetail interlocking joint tenon element14ewhile the dovetail joint recess mortise element12eis formed from left shell12periphery and internal milled elements on the interior surface of left shell12. The specific dimensions of the dovetail tenons and interlocking recesses can be varied depending on different locations on each of the receiver shells.

Referring now toFIG.13A, a conventional first takedown pin24is shown that is used to fasten the left shell12of the receiver to the right shell14of the receiver at an appropriate location after the dovetail interlocking joints have been connected together forming the receiver10. The first takedown pin24includes a movable spring activated locking tab24a. The first takedown pin24fastens the left shell12to the right shell14to prevent potential vertical movement relatively between the left shell12and the right shell14to reinforce and thereby ensure receiver integrity. The first takedown pin24is manually positioned in aperture28in the left shell and in aperture30the right shell (FIG.9) of the receiver to firmly fasten the left and right shells together. The first takedown pin24prevents vertical movement of the left shell12relative to the right shell14to prevent disengagement of the dovetail interlocking joints to firmly secure and hold the receiver left shell12and right shell14together.

FIG.13Bshows a conventional second takedown pin26that is used in the invention in aperture32in the left shell (FIG.9) and in aperture34in the right shell (FIG.5) to secure the left receiver shell12to the right receiver shell14vertically. The second takedown pin26includes a movable spring-loaded tab26athat helps secure and retain the second takedown pin26in position, once it is inserted and fastened to both the left shell12and right shell14, securely holding them together.

The second takedown pin26also prevents vertical movement between the left shell12and the right shell14to prevent disengagement of the left and right shells, forming the receiver10. The use of the first takedown pin24and the second takedown pin26also greatly enhances the integrity of the receiver10formed by the invention, without any welds or rivets, with just the dovetail interlocking joints and two takedown pins to firmly hold the receiver10together.

While the preferred embodiment of the machine-gun receiver has been described herein relating to a representative model of a known machine-gun, Applicants' receiver invention can be utilized and is intended to be utilized to produce numerous different types, calibers, and models of a lightweight machine gun, all of which can or may employ Applicants' invention utilizing the dovetail interlocking joints to interlock a left shell and a right shell body structure, as disclosed.