US 20050108916 A1
A modular barrel assembly for firearms that includes a breech section formed from a high-strength material and a barrel section. the barrel section generally is formed separately from the breech section and can be formed from a different, lighter-weight material. Once formed, the barrel and breech sections are attached together to form the complete barrel assembly.
1. A barrel assembly for a firearm, comprising:
a breech section formed from a high strength material; and
a barrel section formed separately from said breech section and adapted to engage and is attached to said breech section to form the barrel assembly.
2. The barrel assembly of
3. The barrel assembly of
4. The barrel assembly of
5. The barrel assembly of
6. The barrel assembly of
7. The barrel assembly of
8. The barrel assembly of
9. A firearm, comprising:
a fire control; and
a barrel assembly comprising:
a breech section formed from a first, high strength material and adapted to mount to the receiver; and
a barrel section adapted to engage and connect to the breech section down bore from the receiver, the barrel section being formed from a second material of a lighter weight than the first material, and formed separately from the breech section.
10. The firearm of
11. The firearm of
12. The firearm of
13. The firearm of
14. The firearm of
15. The firearm of
16. A method of forming a modular barrel assembly for a firearm, comprising:
forming a breech section from a high strength durable material;
forming a barrel section from a lighter-weight material than the high strength material of the barrel section, the barrel section being formed separately from the breech section; and
connecting the breech section to the barrel section to form a completed barrel assembly.
17. The method of
18. The method of
19. The method of
20. The method of
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25. The method of
The present patent application is a formalization of a previously filed, co-pending provisional patent application entitled “Modular Barrel Assembly” filed Aug. 28, 2003, as U.S. Patent Application Ser. No. 60/498,567; and provisional patent application entitled “Method of Forming Composite Barrel” filed Sep. 10, 2003, as U.S. Patent Application Ser. No. 60/501,884, by the inventors named in this patent application. This patent application claims the benefit of the filing date of the cited provisional patent application according to the statutes and rules governing provisional patent applications, particularly 35 USC § 119(e)(1) and 37 CFR §§ 1.78(a)(4) and (a)(5). The specification and drawings of the provisional patent application are specifically incorporated herein by reference.
The present invention generally relates to firearms, and in particular, to a modular barrel assembly for firearms.
In the manufacture of firearms, and in particular long guns including rifles and shotguns, the production of gun barrels has been performed by a variety of different methods, all of which generally produce a continuous tube. Typically, the tube is formed from a high strength material, such as alloy steel, so as to be capable of withstanding the extreme internal pressures generated during the discharge of a round of ammunition. For example, with the discharge of a shotgun shell, internal chamber pressures in excess of 10,000-15,000 psi can be generated in the chamber and breech sections of the firearm. Firearm barrels typically consist of a chamber or breech region in which the round of ammunition or shell is inserted, and a barrel tube defining the bore of the barrel. Shotgun barrels further typically include a choke section along the barrel, in which a removable choke tube can be received. Externally, the size and length of the barrel tube can vary depending upon the type of firearm, but usually is tapered from the breech or chamber region toward the muzzle end of the barrel in an effort to optimize barrel thickness and weight based on bore pressure variations/reductions as the shot progresses away from the chamber region.
Due to the significant taper or reduction in wall thickness of most typical gun barrels, and in particular shotgun barrels, it is generally not cost effective to machine or cut-down a solid bar or tube having a uniform cross-section to provide the desired taper and reduce the weight of the barrel. Consequently, most firearm barrels typically are hammer forged from shorter blanks to form tapered walled tubes between 20-34 inches in length. Although more cost effective than machining, such forging operations still typically require significant effort and processing to try to ensure straightness of the bore and concentricity of the bore to the outside surface of the barrel. More recently, various composite materials also have been used to form firearm barrels, such as for shotguns, but typically have required a metal liner along their inner wall for protection, thus adding to their cost in terms of both materials and manufacturing.
Accordingly, it can be seen that a need exists for a method and system for forming barrel assemblies for firearms that addresses the foregoing and other related and unrelated problems in the art.
Briefly described, the present invention generally relates to a modular barrel assembly for firearms such as rifles, shotguns and other long guns, and potentially handguns as well. The barrel assembly generally will include a breech or upstream section that generally mounts to the receiver or frame of the firearm, in communication with the chamber of the firearm for receiving a round of ammunition, and a barrel section that attaches to and extends down-bore from the breech section. Typically, the breech section will be formed from a high strength material such as steel, although other high strength materials also can be used, using a forging or machining type process.
The barrel section can be manufactured separately as part of a different manufacturing process than the breech section. The barrel section further can be formed in a variety of different lengths, and can be made interchangeable with other varying length barrel sections. The barrel section generally will include a barrel connector, which typically is formed from a metal material such as steel, similar to the breech section, and a bore tube or section attached to the opposite end thereof. The bore tube or section can be formed from a variety of lighter weight materials, including aluminum, steel, various lighter weight metal alloys and even synthetic and composite materials such as carbon, glass or other fiber composites, and ceramics. The bore section further can be formed using a variety of different processes, depending upon the materials being used therefor, such as, for example, using a roll wrapping, filament winding, or pultrusion type processes for composite or synthetic materials such as carbon fiber, or rolling or extruding where other types of material, such as metals, are used. The bore section generally will be connected to the barrel connector such as by an adhesive, although other types of chemical, mechanical, and/or metallurgical bonding techniques also can be used. A rib also can be formed with or can be attached to the bore section to provide added stiffness for the barrel assembly. Still further, a muzzle insert, typically formed from a metal such as steel or other similar material, can be attached to the down bore end of the bore section.
The breech and barrel sections of the barrel assembly of the present invention generally will be attached together in a downstream assembly step. The barrel and breech sections can be attached together using metallurgical (welding, brazing, fusing, soldering, etc.), and/or chemical (adhesives) bonding techniques. Still further, it is also possible to mechanically attach the barrel and breech sections together (such as via fasteners; a threaded connection between the breech section and the barrel connector; or through a press-fit arrangement between the two sections and use of a locking ring) so as to enable removal and replacement or interchangeability of the barrel and/or the breech sections of the barrel assembly.
Various objects, features and advantages of the present invention that will become apparent to those skilled in the art upon reading the following detailed description, when taken in conjunction with accompanying drawings.
The present invention relates to a modular barrel assembly 10 (
As illustrated in
The breech section 20 generally will be manufactured from a high strength material, such as steel, titanium, or other similar high strength, rigid, durable metals or metal alloys, since the breech section generally will be subjected to the highest internal chamber pressures resulting from the ignition of the propellants in a round of ammunition, such as a bullet or shot shell, during firing of the firearm. As indicated in
As further indicated in 1-3, the breech section 20 generally includes an elongated tubular body 25 having a first or rear end 26, a second or forward end 27, and defines a bore passage 28 therethrough. The rear end 26 of the breech section generally is formed as a collar or sleeve 29 having an enlarged or expanded diameter that tapers, as indicated at 31, toward the forward end 27 of the breech section. The rear end 26 of the breech section is adapted to engage and mate with the receiver 11 of the firearm F, as indicated in
As illustrated in
Since the pressure containment requirements of the bore tube or section 39 of the barrel section 21 generally will be lower than the breech section 20, the bore tube 39 can be made from a variety of different, lighter-weight, materials than the breech section. For example, various metals including steel, aluminum, and/or lightweight, durable metals or metal alloys typically are formed by forging or machining a tube of a desired length. Since there generally is a minimal taper to the bore tube, and lighter-weight metal materials can be used, less forging or machining, and thus less scrap, typically will be required to form the bore tube from such a metal material. Alternatively, for more significant weight reduction, the bore tube 39 also can be formed from various synthetic or composite materials such as fiberous material, including carbon, glass, graphite, boron, nickel coated carbon, and/or silicon carbon fiber, and resin composites, ceramics, various high strength plastics, nylon and/or other similar, rigid, durable materials. Example resins could include epoxy resins, polylimide resins, polyester resins, thermoplastic resins and/or other, similar resin materials. The formation of such a composite or synthetic bore tube can be accomplished with a variety of manufacturing techniques including filament winding, pultrusion, and roll-wrapping processes.
In an example of a roll-wrapping process, a series of layers, typically 3-4 or more layers or strips of a unidirectional or balanced ply fabric material, such as a carbon fiber ribbon or similar composite fabric material will be laid out in stacked layers. Typically, a unidirectional pre-impregnated (prepreg) fabric in which essentially all of the fibers of the composite fiber fabric are pre-impregnated with an uncured resin will be used, with a majority of fibers or filaments of the fabric material bound in the hoop direction (approximately 90° to the axis of the bore 41, extending through the bore tube) and with the remaining oriented longitudinally, substantially parallel to the axis of the bore 41 so as to provide additional longitudinal stability and tensile strength, or at varying angles, such as approximately 45° with respect to the axis of the bore so as to provide further torsional stability to the bore tube. Dry fabrics can also be used with the resin materials to be applied during later processing at a later step. A mandrel, which will form the inside diameter and surface of the bore tube, generally is placed at one end of the stack or plies or layers of fabric material. The fabric assembly then is rolled tightly around the mandrel, such as by using a table having a fixed plate and moveable plate that exert a load or compressive force on the stacked fabric layers therebetween. The moveable plate will be slid in a direction perpendicular to the axis of the mandrel, causing the mandrel to roll the plies or layers of the fabric material onto the mandrel under constant pressure to form a composite bar or tube, with the mandrel in its center.
The composite bar or tube is then wrapped with a clear ribbon or tape material, to maintain compressive stresses about the exterior of the bar. The whole assembly is then cured, typically by placement in a curing oven and being subjected to temperatures of upwardly of 325° F for approximately 2 hours, or at other temperatures and for other times as may be necessary to cure the resin material applied to the layers. Alternatively, the resin material can be chemically cured, such as by amine/epoxy, anhydride/epoxide and/or acid-catalyzed epoxide reactions. The mandrel is then extracted from the cured bar, leaving the composite bore tube. The exterior of the bore tube then generally is finished, such as by sanding or grinding the exterior wall of the tube, to provide a smooth, flat finish, after which a clear coat typically is applied.
Alternatively, a composite or synthetic bore tube can be manufactured using a filament winding process in which strips or layers of a unidirectional fabric material are wound together using a filament winding machine. During this process, the winding can be stopped periodically for application of additional layers of a unidirectional fabric, which typically are hand laid onto the assembly to achieve a zero degree orientation of the layers in the composite pre-form.
As a further alternative, a composite or synthetic bore tube can be formed using a pultrusion method in which a composite material, such as a ceramic or fibrous material having a resin applied thereto, will be pulled through a heated die that serves to further cure the composite material, to thus form a tube of a desired length. Such a process is generally can yield the lowest cost per unit length; however, it typically will not provide the same levels of strength in the finished bore tube as provided with roll-wrapping or winding methods.
The barrel connector 36 and muzzle insert 38 typically will be formed form a standard alloy, steel, aluminum, or other metal material similar to the breech section. The barrel connector 36 and muzzle insert 38 can be attached to the bore tube at the opposite ends thereof by various chemical methods of attachment, including use of various types of epoxies, resins and/or other adhesive materials for adhesively attaching the barrel connector and muzzle insert to the composite material of the bore section. Additionally, various other types or methods of attachment also can be used, including, but not limited to, welding; fusing; brazing; soldering or other metallurgical methods of attachment; and/or various mechanical attachments, such as through the use of fasteners, such as screws, pins, rods, banding materials, a threaded connection between the barrel connector and bore tube, press fitting the sections together, and/or other, similar connectors.
In addition, as shown in
To assemble the barrel assembly of the present invention, the barrel section will be attached to the breech section, as indicated in
In addition, for a barrel assembly for a shotgun, such as generally illustrated in
It will be understood by those skilled in the art that the principles of the present invention can be adapted to formation of barrel assemblies for a variety of different firearms, including rifles, shotguns and other long guns, as well as potentially to handguns as needed or desired. The module barrel system of the present invention thus enables the interchangeability of firearm barrels for quick conversion of a firearm to fire different types of rounds of ammunition, such as shot shells, rifle slugs, etc., and to provide ease of repair and replacement for a firearm barrel as needed. The present invention further enables the use of lighter weight materials during the manufacture of a barrel assembly, which enables a significant cost and weight reductions for the barrel assembly and thus its firearm, as well as ease of manufacture for the barrel assembly.
It will be further understood by those skilled in the art that while the foregoing has been disclosed above with respect to preferred embodiments or features, various additions, changes, and modifications can be made to the foregoing invention without departing from the spirit and scope of thereof.