The present disclosure relates generally to firearms and, in particular, to a feed ramp assembly for directing cartridges into the chamber of a firearm.
Fire control mechanisms and actions for modern auto-loading firearms are generally highly-engineered mechanical devices that are designed with tight spacings/tolerances, and necessarily must operate reliably for a high number of firing cycles. For example, automatic and/or semi-automatic firearms, such as M16/AR15, M4, and AK-47 auto-loading rifles generally are required to fire thousands of rounds, especially for military uses such as under battlefield conditions, without failure. During firing of such auto-loading firearms, as the spent casing is ejected, a new round of ammunition will be received from a magazine and loaded into the chamber of the firearm. As the bolt is moved forward and pushes the round of ammunition into the chamber, the bolt generally undergoes a partial rotation so as to engage a series of locking lugs with a series of barrel lugs, thereby locking the bolt into position and sealing the round of ammunition within the chamber.
Feed ramps generally are used to guide the rounds of ammunition from the magazine into the chamber, and are typically machined into the material of the barrel or barrel extension that surrounds the breech opening, such as by enlarging or expanding one or more of the gaps that separate the barrel lugs, and, in rifles such as the M4, can extend into/be matched with feed ramps formed in the upper receiver. During a loading operation, the ammunition cartridges rub against the feed ramp, causing peening, galling or wear of the feed ramp surfaces, especially tamp surfaces formed in the receiver, which typically can be formed from metals such as aluminum that provide a reduction in weight but have lower impact toughness than steel or similar materials. Dirt and debris further can be trapped at the feed ramp surfaces, causing additional or faster wearing of the ramp surfaces, and/or leading to jams or failure of the feed ramp. Thus, polishing and repair of feed ramps can be required on a frequent basis to maintain such auto-loading firearms. Additionally, it is becoming increasingly popular for many firearms, in particular for military or tactical uses, to be modifiable to the different types of ammunition, and thus, it is necessary that the surfaces of the feed ramps be able to accommodate the use of such ammunition.
Accordingly, there exists a need for an improved feed ramp system for directing cartridges into a chamber of the firearm that provides for a reduction in wear and galling on the interior surfaces thereof. It is to the provision of a solution to this and other problems that the present disclosure is primarily directed.
Generally described, the present disclosure relates to a feed ramp system for directing cartridges into the firing chamber of a firearm. The feed ramp system generally will include a replaceable feed ramp that can be removably mounted adjacent the breech end of a barrel of the firearm. The firearm barrel will include a bore that extends along a longitudinal axis from its first or breech end and a muzzle end. A barrel extension can be mounted at the breech end, including a breech face that leads to a chamber formed in the barrel. The breech face is defined by a circumferential rim and includes a plurality of barrel lugs extending radially inwardly from the circumferential rim and that are spaced from each other by a plurality of lug gaps. The circumferential rim further can include a notch or recess defined in a lower portion thereof and along which enlarged and/or sloped gap surfaces can be defined, which can thus form a pair of distal ramp surfaces in the barrel or barrel extension.
The feed ramp system includes a feed ramp insert having a body formed from a high strength, wear resistant material. In one embodiment, the material of the insert generally can include a metallic material that is different from the metallic material of the receiver. The insert body will be configured to be removably coupled to the receiver and can include a central guide section or ramp portion configured to be received and extend into the notch in the breech face or the barrel or barrel extension. A pair of proximal ramp surfaces generally will be formed in the guide section, the ramp surfaces being sloped relative to the longitudinal axis. The proximal ramp surfaces further can be configured to align with the distal ramp surfaces of the breech face of the barrel or barrel extension to form the firearm feed ramp structure for directing cartridges into the chamber of the firearm.
Another embodiment of the present disclosure includes a feed ramp insert for a firearm having a barrel and/or a barrel extension with a breech face adjacent a chamber, a receiver coupled to the barrel, and a bolt moveable within the receiver to move a cartridge from a magazine into the chamber through the breech. The breech face of the barrel or barrel extension is defined by a circumferential rim and includes a plurality of barrel lugs extending radially inward from the circumferential rim and spaced from each other by a plurality of lug gaps. The breech face further can include a notch extending axially through the circumferential rim and along which a pair of distal ramp surfaces can be formed.
The feed ramp insert includes an insert body that will be configured for installation within the receiver, generally being received in a mating aperture or recess formed along a front face of the receiver, and which can further be received in a mating engagement with the notch of the barrel breech face. One or more attachment tabs or members can extend from the insert body, and can receive locking pins, fasteners or other, similar elements, to removably couple the insert body to the receiver. A pair of proximal ramp surfaces also is formed into the insert body, the ramp surfaces generally being sloped relative to the longitudinal axis of the barrel. The proximal ramp surfaces can be configured to align with the distal ramp surfaces of the barrel breech face to form combined or composite feed ramp surfaces for directing cartridges into the chamber.
The specific structures and techniques employed to improve over the drawbacks of the prior devices and accomplish the advantages described herein will become apparent from the following detailed description of representative embodiments and the appended drawings and claims.
Those skilled in the art will appreciate and understand that, according to common practice, various features of the drawings discussed below are not necessarily drawn to scale, and that dimensions of various features and elements of the drawings may be enlarged or reduced to more clearly illustrate the embodiments of the present invention described herein.
The embodiments of the invention and the various features thereof are explained below in detail with reference to non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of certain components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law.
It is to be understood that the invention of the present disclosure is not limited to the specific devices, methods, conditions, or parameters of the representative embodiments described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only. Thus, the terminology is intended to be broadly construed and is not intended to be unnecessarily limiting of the claimed invention. For example, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, the term “or” means “and/or,” and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. In addition, any methods described herein are not intended to be limited to the sequence of steps described but can be carried out in other sequences, unless expressly stated otherwise herein.
Generally described, the present disclosure relates to a feed ramp system for directing cartridges into a chamber of the firearm, shown here as an auto-loading rifle. It is to be appreciated, moreover, that applications of the feed ramp system are not limited to auto-loading rifles, and may include bolt action or lever action rifles and the like, auto-loading or pump action shotguns and the like, and other varieties of pistols and firearms. As described below, the feed ramp system of the present disclosure can provide several significant advantages and benefits over other feed ramp systems and methods for loading rounds of ammunition into the chamber of the firearm. However, the recited advantages are not meant to be limiting in any way, as one skilled in the art will appreciate that other advantages may also be realized upon practicing the present disclosure.
As shown in
One or more of the lug gaps 37, typically located along a lower portion of the breech face 27, adjacent the opening or portion of the receiver through which the cartridges from the magazine are received for feeding to the chamber, can be machined or enlarged to form one or more distal ramp surfaces 38. These distal ramp surfaces 38 generally can be formed at a first angle or slope relative to the longitudinal axis 21 of the barrel 20. The distal ramp surfaces 38 can form the upper portion of one or more bifurcated or combination firearm feed ramps 76 that can be used to direct cartridges from the magazine into the chamber of the firearm.
In one embodiment of the feed ramp system as shown in
As shown in the embodiment illustrated in
To accommodate the feed ramp insert 60, the notch 28 of the barrel extension/barrel can be formed in the breech face 27 of the barrel 20 and extended axially through the circumferential rim 32 to at least partially shorten the one or more lug gaps 37 that have been enlarged to form a distal ramp surface(s) 38. In embodiments shown in
Upon assembly of the barrel 20 with the receiver 40, the notch 28 in the barrel 20 can become aligned with the mating recess 54 formed in the receiver. The central guide section of the insert body 62 can be matingly received within the aligned notches/recesses 28 and 54, in a tolerance fit, with the attachment tabs 66 of the insert body generally being aligned with and/or engaged and received within attachment slots 56. The attachment slots 56 generally can be formed in an underside surface of the receiver and can be configured to receive attachment tabs 66 that extend laterally from the body of the feed ramp insert 60 (
As noted above and as illustrated in
In one embodiment, the barrel 20 (
In one embodiment, the feed ramp can be formed from a similar hardened steel alloy material as the barrel 20, so that the proximal ramp surfaces 68 and the distal ramp surfaces 38 that together form the bifurcated feed ramps 76 have the approximately same surface hardness. Indeed, in other aspects it may also be desirable for the feed ramp insert 60 to be made from an alloy material that is harder and more impact resistant than the hardened steel alloy forming the barrel 20, so that the proximal ramp surfaces 68 have a surface hardness and impact resistance that is greater than that of the distal ramp surfaces 38. The use of such materials having higher or increased impact toughness can provide for smoother feeding of cartridges, while at the same time, reducing wear, peening and/or galling of its surfaces, thus potentially increasing the operating cycles of the firearm while reducing maintenance and polishing required for the feed ramps.
As can be seen in
The replaceable design of the feed ramp system of the present disclosure can enable the gun designer, manufacturer, or end user to control the preferred area of contact between the cartridge and the bifurcated feed ramps 76. For example, in one aspect the surface area of the pair of proximal ramp surfaces 68 can be greater than or about 40% of the total surface area of the pair of bifurcated feed ramps 76. In other embodiments, the surface area of the pair of proximal ramp surfaces 68 can be greater than or about 50% of the total surface area of the pair of bifurcated feed ramps 76, or even 60% of the total surface area of the pair of bifurcated feed ramps 76. Changes to the surface area of the proximal ramp surfaces 68 can be accomplished in a variety of ways, including changes in the thickness of the feed ramp insert 60 as well as changes in the shape or geometry of the proximal ramp surfaces 68.
For instance, in another embodiment of the feed ramp system illustrated in
In yet another embodiment of the feed ramp system illustrated in
The ability to quickly and easily replace the feed ramp, which thus enables the use of different configuration feed ramps in which various characteristics of the proximal feed ramp surfaces, including the surface hardness, the surface area, or the shape and geometry of the surface, and the like, can be modified, can allow for the rapid and efficient customization of the firearm to accommodate different types ammunition, feed angles, and bullet types. The ability to modify the proximal feed ramp surfaces can also extend the service life of the receiver and the breech end of the barrel, including the barrel extension. It is contemplated that these and other advantages may be realized upon practicing the present disclosure.
The invention has been described in terms of preferred embodiments and methodologies considered by the inventors to represent the best mode of carrying out the invention. A wide variety of additions, deletions, and modification might well be made to the illustrated embodiments by skilled artisans without departing from the scope of the invention. In addition, it is possible to use some of the features of the embodiments described without the corresponding use of the other features. Accordingly, the foregoing description of the exemplary embodiments is provided for the purpose of illustrating the principle of the invention, and not in limitation thereof, since the scope of the invention is defined solely be the appended claims.
The present Patent Application is a continuation of previously filed co-pending U.S. patent application Ser. No. 14/590,370, filed Jan. 6, 2015, which application claims benefit of U.S. Provisional Patent Application Ser. No. 61/926,473, filed Jan. 13, 2014 according to the statutes and rules governing provisional patent applications, particularly 35 U.S.C. §119(e) and 37 C.F.R. §1.78(a)(3)-(4). The specifications and drawings of each of said applications referenced above are specifically incorporated herein by reference as if set forth in their entireties.
Number | Date | Country | |
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61926473 | Jan 2014 | US |
Number | Date | Country | |
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Parent | 14590370 | Jan 2015 | US |
Child | 14630014 | US |