REINFORCED RIFLE STOCK

Abstract

A rifle stock is configured to receive a barreled action having an attached barrel and a lower surface which also has a downward protrusion. A shell having an exterior surface defines an exterior and an interior of the stock. The shell has opposed sidewalls extending from a bottom portion and an intermediate portion. A span element which is preferably a planar element and at least in part encompassed by fill material spans between the opposed sidewalls. The span includes a structural element that connects to the shell, a transverse intermediate portion, vertical end portions, and a forward edge for a protrusion receptacle which is defined in part by fill material in the stock and in part by the span element. The protrusion receptacle receives a downward extending protrusion of the rifle action. The fill may comprise rigid foam, composite materials, carbon fiber, or combinations of these materials.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 63/231,781, filed on Aug. 11, 2021, entitled “Composite Stock Recoil Load Shelf,” which is hereby incorporated by reference in its entirety for all that is taught and disclosed therein.

FIELD OF THE INVENTION

The present invention relates to stocks for shoulder-fired firearms.

BACKGROUND AND SUMMARY

Rifle stocks enable a shooter to comfortably and securely support a firearm so that a shooter may point the rifle at an intended target. Traditional rifle stocks offer a stable and unyielding platform so that while collecting recoil force while the bullet is being expelled through the rifle barrel, the shooter is able to maintain a preferred alignment of the barrel axis with respect to a desired trajectory once the bullet leaves the barrel.

Rifle stocks are also designed to transfer the impulses from the combustion and propulsive events to the supporting elements of the shooter's body; mostly to the shoulder but also in part through the shooter's hands and arms, especially if the stock includes a sling.

In many shooting sports and in tactical and military uses a primary unwanted element in rifle stocks is weight, and so a primary objective of the invention is to provide a rifle stock offering desirable rigidity while having the least amount of mass in unnecessary areas where material does not contribute substantially to structural rigidity or resilience of the material while withstanding recoil forces.

A corollary objective of the invention is to provide a substantially rigid rifle stock wherein material deformation during recoil and recovery from recoil is entirely elastic so that no permanent deformation or dislocation of the features and structures of the rifle stock would occur from one shot to the next, or over the service life of the stock.

The above challenges and disadvantages in the current art are addressed by providing a hollow or at least partially hollow stock comprising a rigid exterior shell, and installing therein a small, strong span made of a carbon fiber composite, a metal or similar substantially rigid material, structurally adhered to the shell before adding internal filler material such as foam. The rifle stock is configured to receive a barreled action having a downward protrusion. The shell portion of the stock has opposed sidewalls extending from a bottom portion and an intermediate portion. The span element spans between the opposed sidewalls, and includes a structural element that connects to the shell, and also contributes a forward edge to a protrusion receptacle defined in part by fill material in the stock and in part by the span element itself. The protrusion receptacle receives the downward extending protrusion of the rifle action. The fill may comprise rigid foam, composite materials, carbon fiber, or combinations of these materials.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a shows a right side view of a rifle which includes an embodiment of a reinforced rifle stock in accordance with the invention.

FIG. 1b shows a top view of the rifle and stock of FIG. 1, defining section line A-A for the cross section view of FIG. 5 and section line B-B for the cross section view of FIG. 6.

FIG. 2 shows an embodiment of a reinforced rifle stock in accordance with the invention with some components exploded for discussion.

FIG. 3 shows a top view of an embodiment of a span element for a reinforced rifle stock in accordance with the invention.

FIG. 4 shows an oblique, top rear right side view of a barreled action engaging with exploded components of a reinforced rifle stock in accordance with the invention.

FIG. 5 shows a cross section view of the barreled action and reinforced rifle stock of FIG. 1, taken at section line A-A of FIG. 2.

FIG. 6 shows a cross section view of the barreled action and reinforced rifle stock of FIG. 1, taken at section line B-B of FIG. 2.

FIG. 7a shows an intermediate portion of an embodiment of a reinforced rifle stock in accordance with the invention having a span element embedded in fill material within the shell of the stock.

FIG. 7b shows the intermediate portion of the reinforced rifle stock of FIG. 7a without the hidden lines of the span element.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Traditional composite stocks consist of a strong composite shell that makes up the exterior shape of the stock which is filled with an epoxy or foam fill that fills the interior of the shell. The fill is molded or machined to accept the metallic components of the rifle. The molded or inletted portion is called the inlet. The recoil of the rifle is generated in the barreled action. The recoil impulse is transferred from the recoil lug of the action into the fill of the stock. The stock fill then transfers the recoil impulse into the composite stock shell. The shell of the stock then transfers this impulse to the recoil pad and then into the shoulder of the shooter.

Because the fill has to transfer the recoil from the barreled action to the composite shell, it has to be strong enough to withstand this energy. The fill also makes up the majority of the volume of a stock so its weight plays a major role in the overall weight of the stock. Selecting a fill material that is both extremely lightweight and yet still strong enough to transfer the recoil impulse is difficult. Some composite rifle stocks have aluminum bonded or embedded into the fill to help transfer this load. The aluminum is much heavier than the fill or the composite shell.

The present invention places a supporting shelf of lightweight composite material inside the fill that can interact with the recoil lug and transfer the recoil impulse directly from the recoil lug to the shell of the stock. One possible method of attaching the recoil shelf onto the stock shell is to bond it on with epoxy. The recoil impulse would then be transferred from the shelf, through the epoxy bond, and into the stock shell. The action is spaced apart from the recoil shelf by the stock fill, except where the lug contacts the edge of the recoil shelf. By transferring the recoil impulse through the recoil shelf instead of the stock fill, less load is placed on the stock fill so the fill does not have to be as strong, and can be made of a much lighter weight material.

Referring now to the figures, FIG. 1a shows a right side view of a rifle which includes an embodiment of a reinforced rifle stock [10] in accordance with the invention. The rifle stock is configured to receive a barreled action [3] having an attached barrel [2.] The rifle stock comprises a rigid exterior shell with internal reinforcements and optional fill materials. The shell has opposed ends [4a] and [4c] and an intermediate portion [4b] proximal to the barreled action of the rifle. A typical length dimension [L] for the rifle stock may range between about 18 to about 40 inches, an a typical height dimension [h] at the butt of the rifle stock may range between about 3¼ inches to about 8 inches.

FIG. 1b shows a top view of the rifle and stock of FIG. 1, defining section line A-A for the cross section view of FIG. 5 and section line B-B for the cross section view of FIG. 6.

FIG. 2 shows an embodiment of a reinforced rifle stock in accordance with the invention with some components exploded for discussion. The stock [1] is shown here without the butt plate and shoulder pad components and is preferably embodied as a hollow shell to reduce its weight. The stock assembly includes pillars [6,7] for withstanding the compression forces of threaded fasteners [8,9] which engage in threaded holes in the action or receiver of the rifle to secure the barreled action to the stock. According to the invention, an additional component variously called a shelf, a span, a bridge, or a span element [15] is also deposited into the hollow intermediate portion of the stock. When the barreled action is installed into the stock, it mechanically couples to the span so that the span contributes to supporting the action during recoil and contributes to transferring the recoil impulses from the action directly to the rigid external shell of the stock.

FIG. 3 shows a top view of an embodiment of a span element [15] for a reinforced rifle stock in accordance with the invention. The span has an aperture which in whole or in part defines a protrusion receptacle [18] for receiving a protrusion of the rifle's action as illustrated in other figures. The span has a first forward edge [19] at the protrusion receptacle which may also include an arcuate or concave portion [20] for receiving or for clearance of a portion of the pillar [7.] The span may also include a second forward facing edge [19′] or face which is not part of the perimeter of a protrusion receptacle. Although in preferred embodiments the recoil lug is received within the aperture of the span, it is also within the scope of the invention for the span to abut and support the recoil leg at its second forward facing edge.

FIG. 4 shows an oblique, top rear right side view of a barreled action engaging with exploded components of a reinforced rifle stock in accordance with the invention. A component of the rifle action such as a receiver includes a lower surface [23] which has a downward protrusion [24] also called a recoil lug. One from among several threaded fasteners is shown threadably engageable to the rifle action. The fastener passes through the exterior shell of the stock and through a pillar [7] embedded or incorporated within the fill material of the stock. The pillar may also be affixed to the shell of the stock and may also optionally include internal threads. The pillar avoids over-compression of the fill material of the stock by preventing over-tightening of the fastener. When assembled, the recoil lug or protrusion is received in to a protrusion receptacle [18] of the span element [15] and abuts a forward facing edge or face of the protrusion receptacle. With the opposed sidewalls [16] of the span also securely affixed to interior surfaces of the shell of the stock, the span element stabilizes the action and barrel during recoils.

FIG. 5 shows a cross section view of the barreled action [23] and reinforced rifle stock of FIG. 1, taken at section line A-A of FIG. 1b. During discharge of a cartridge, recoil force originates at the bolt face and is opposed at the recoil lug. The tang or rear facing surface of the downward extending protrusion [24] inserts into the protrusion receptacle defined at least in part by the aperture in the span element [15] which is seen in this view as a planar element. The forward edge [19] of the aperture in the span element abuts the recoil lug so that the span may accept a portion of the recoil impulse.

The shell [31] of the rifle stock may be formed of any suitable and substantially rigid material such as polyamide (Nylon®) which may a common 6 polyamide or a cross-linked nylon such as a 4-6 or 6-6 polyamide. Other suitable polymer and synthetic materials include polypropylene, fiber infused resins such as a fiberglass and epoxy composite material, or a composite comprising a carbon fiber material. Natural materials such as wood may also be used for the shell of a rifle stock in accordance with the invention. A shell thickness [t] may range between about 1/32^th of an inch to about ¾ of an inch.

The stock may be constructed as a hollow or partially hollow assembly in which the shell contains the span and the pillars only, but preferably includes a fill material [32] at least partly occupying the hollow interior. If created by additive manufacturing, the interior of the stock may include trussworks or frameworks which may further comprise longitudinal or transverse beam elements, or comprise beam elements aligned to withstand the recoil force in columnar loading. Similarly, the orientation of fibers in a composite material may be axially aligned with the recoil stresses which the shell withstands during recoil. Also, the cross sectional density of the fiber or other substrates of the composite material may be increased in portions of the shell which carry higher working or principal stresses. The fill material may be natural or may be a rigid foam, and the interior of the stock may be partially filled and partially hollow. The density of the foam may be controlled by void sizes, and the density may be varied such as being increased in the vicinity where the span transfers recoil force to the shell.

FIG. 6 shows a cross section view of the barreled action [3] and reinforced rifle stock of FIG. 1, taken at section line B-B of FIG. 1b. The stock comprises a shell [31] having an interior and an exterior surface defining an exterior of the stock. The shell has a bottom portion [33] and opposed sidewalls [34] extending from the bottom portion. A span element [15] is at least in part encompassed by fill material [32] and the span is connected to the shell. The span element has a transverse intermediate portion [17] and vertical end portions[16,] and extends between the opposed sidewalls [34,] and includes a structural connection [35] to the shell. The gaps between the side walls of the span element and the internal walls of shell allow space for epoxy or other adhesives. The downward extending protrusion [24] or recoil lug of the rifle action resides in the protrusion receptacle of the stock assembly and extends below the planar portion of the span element. Although less preferred, the span element may also be attached to the interior of the shell of the stock by mechanical fasteners.

FIG. 7a shows an intermediate portion of an embodiment of a reinforced rifle stock in accordance with the invention having a span element [15] or bridge embedded within fill material [32] within the shell [31] of the stock. The stock defines a protrusion receptacle configured to receive the downward protrusion of the rifle action and the span at least in part defines the protrusion receptacle. The span has a forward edge at the protrusion receptacle for supporting the recoil lug. The protrusion receptacle may be defined in part by the fill material and in part by the span element, or may be defined entirely by the aperture in the span element if fill material is not present.

FIG. 7b shows the intermediate portion of the reinforced rifle stock of FIG. 7a, but without the hidden lines of the span element shown. The stock assembly provides a strong structure for resisting internal compression so as to stabilize the receiver during recoil. The stock may be assembled in steps, such as forming and providing a hollow stock comprising a rigid material, and providing a strong span of metal or similar material to be structurally adhered to the interior of the shell before a foam fill is deposited within the interior of the shell. The protrusion receptacle may be machined into the fill and into a span element initially lacking an aperture in a single machining step.

In a preferred embodiment the recoil lug is coupled not to the foam but instead abuts a shelf attached to the shell, which may even allow elimination of the foam entirely or the use of highly cancellous material or truss-like structures as an internal structure designed to transfer recoil forces to the rigid exterior shell. The shelf may be designed to provide elastic compression during recoil, which is fully restored as it would be undesirable to allow plastic or permanent deformation of the support components in the stock assembly.

In constructing the hollow shell for the stock, an embodiment may utilize composite materials comprising unidirectional, bidirectional, or multidirectional materials, and may include additional layers of composite materials such as carbon fiber and resin or fiber glass, and may include increasing a density of reinforcing fibers in the vicinity where recoil forces are more concentrated. Additionally, a composite material structure in accordance with the invention may align or converge fiber portions of composite matrix to address localized high stress zones. In an alternative embodiment, foam or other fill material may not be required if other structures are substituted which adequately support and preserve the exterior ergonomic shape of the shell of the stock.

Thus, although many exemplary embodiments are described above, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.

Claims

1. A rifle stock configured to receive a barreled action having an attached barrel and a lower surface,

and having a downward protrusion,

the stock comprising a shell having an exterior surface defining an exterior of the stock and having an interior;

the shell having a bottom portion and opposed sidewalls extending from the bottom portion;

the shell having opposed ends and an intermediate portion; a fill material at least partly occupying the interior, and

a span element at least in part encompassed by the fill and connected to the shell.

2. The rifle stock of claim 1, wherein the span element spans between opposed sidewalls.

3. The rifle stock of claim 1, wherein the span has a structural connection to the shell.

4. The rifle stock of claim 1, wherein the span is a planar element.

5. The rifle stock of claim 1, wherein the span has a transverse intermediate portion and vertical end portions.

6. The rifle stock of claim 1, wherein stock defines a protrusion receptacle configured to receive the protrusion, and wherein the span in part defines the protrusion receptacle.

7. The rifle stock of claim 6, wherein the span has a forward edge at the protrusion receptacle.

8. The rifle stock of claim 6, wherein the protrusion receptacle is defined in part by the fill material and in part by the span element.

9. The rifle stock of claim 1, wherein the fill is a rigid foam.

10. The rifle stock of claim 1, wherein the shell is formed of a composite material.

11. The rifle stock of claim 1, wherein the shell is formed of carbon fiber material.