Quick change barrel system for a firearm

The present invention is an improved quick change barrel system for a firearm. It features an interlocking trunnion and lock ring that hold the barrel in place proximate the receiver. Intermittent threading provides multiple points of interface. A foldable handle is provided to allow safe removal of the lock ring and additional torque for attachment and removal of the lock ring from the system.

FIELD OF THE INVENTION

The present invention relates to the field of firearms and more particularly relates to a new rifle platform with enhanced utility innovative components and increased modularity.

BACKGROUND OF THE INVENTION

Prior firearms have been, as a whole, adequate for their purposes. However, the advent of improved technologies in other fields, combined with the demands of current military tactics, both offensive and defensive, have created a need for a firearm that improves upon the current designs in the art. Practically speaking, the need has arisen for a lighter and more efficient weapon; one that is easily maintained, simple to operate and assemble, and easily enhanced as need requires.

Of particular need is a quick change barrel system. Quickly changeable barrel systems are well known in the field of crew-served weapons such as machine-guns. These weapons are primarily belt-fed, fully-automatic, operate with an open-bolt mechanism and are intended to be used in roles requiring maximum firepower. Due to the quantity and rate of fire, these weapons generate a significant amount of heat, primarily in the barrel and gas operating system (if one is present). The temperatures generated significantly affect weapon function by burning off lubricating oils, altering critical tolerances as parts expand at differential rates (depending on material), and temporarily and/or permanently weakening structural materials. This may cause various malfunctions including critical weapon failure (feeding & extraction failures, blown barrels, bolt failure etc.). To avoid these affects, cooling systems such as fins, fluting, increased forced air convection and water cooling have been employed historically. However, these systems can have various drawbacks including low effectiveness, weight, bulk, complexity and cost. Because of this, modern machine-guns such as the US M60 GPMG, FN MAG/M240 GPMG, and M2HB-QCB all utilize quick-change barrel (QCB) systems to completely replace a hot barrel with a fresh one.

Rifles are not expected to generate the heat levels seen on machine-guns. Therefore rifle barrels have traditionally been considered an integral part of the firearm. Barrels were never intended to be readily removed especially at the operator level. While this approach has worked historically, this type of design has imposed a number of limitations on these systems. With increased detachable box magazine capacity, lighter ammunition and the demands of high-end users such as special forces operators, rifles are experiencing heat issues similar to machine-guns. QCB systems allow similar barrel swaps to prolong weapon use under intense operational circumstances.

These limits have given rise to rifle systems and modifications designed to allow users to change the barrel. Systems such as the LMT Monolithic Rail Platform (MRP) and FN SCAR attach the barrel with a number of screws requiring additional tooling in order to operate. Other systems are true QCB systems such as the Leitner-Wise Modular Weapon System (MWS) and MGI Hydra that incorporate two-point lateral lever or cam systems which mount the barrel and allow quick change ability without tools. The benefits of such systems are numerous and include mission adaptability, easier serviceability, easier caliber change of the weapon, and more compact storage.

The present invention is an improved QCB system with numerous improvements that make it simpler to operate and maintain as compared to the prior art.

SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types of barrel systems, this invention provides an improved quick change barrel system with increased utility, intuitive use and rapid deployment. As such, the present invention's general purpose is to provide a new and improved quick change barrel system that is more efficient to operate and maintain, and presents an intuitive interface for users.

To accomplish these objectives, the quick change barrel system comprises a barrel which is mounted in a cantilevered manner. The rear of the barrel slides and mounts into a barrel trunnion and is subsequently locked into place with a barrel lock ring via an interrupted, non-continuous thread that mates with the barrel trunnion. A folding wire handle is provided to assist in applying leverage to turn the barrel lock ring thereby applying pressure to the barrel extension flange and providing a sealed joint. A spring-loaded detent (barrel lock plunger) locks into grooves on the barrel lock ring to prevent it from working loose.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference now to the drawings, the preferred embodiment of the firearm is herein described. It should be noted that the articles “a”, “an” and “the”, as used in this specification, include plural referents unless the content clearly dictates otherwise.

With reference toFIG. 1, the firearm10, as disclosed in the parent provisional application, has four major components, namely the barrel412, receiver414, grip housing416and stock418. Internal parts are generally located in the receiver414and grip housing416.FIG. 2depicts a trigger control group415and a magazine413as residing in the grip housing416and a short stroke gas piston system417and charging system419in the receiver414. The firing pin418is also located in the receiver414.

The firearm410has a free floating barrel412which is cantileverally attached to receiver414(FIG. 2). The barrel assembly itself is depicted inFIGS. 3-5. In these depictions, a stripped M-16/AR15 barrel is used. In the present invention, barrel412is mounted upon a lock ring422which interfaces with the barrel trunnion426. It should be noted that the barrel412is not fused to the lock ring422, so that generic barrels, with flanges430(FIGS. 6 and 7), may be used with this invention. A foldable wire handle424extends from the lock ring422to aid in assembly and disassembly of the barrel structure from the firearm. Mounted over the barrel412is the gas piston assembly417, which comprises, among other things, a piston rod409. The piston rod409is held in place by two rod guides, one on the barrel405, and the other on the barrel trunnion407.

Barrel trunnion426and lock ring424have non-continuous, interrupted thread interfaces428,428a(best seen inFIGS. 6,7,12and14) and a locking structure to hold them together. The non-continuous, interrupted thread pattern is preferred as it provides points of quick attachment/detachment to further increase speed. The interruptions may provide as few as one such points, but it is preferred that three or more are used, with an ideal range of 3 to 5 such points. The preferred locking structure is a detent pin (or lock plunger)425, biased by spring429, which interfaces with flat ridges421on the lock ring422(one shown) to prevent rotation, thus keeping the lock ring422and barrel trunnion426together (FIGS. 8 and 10). These ridges421must, of course, be manufactured to coincide with the interrupted threads428,428a. When held together, the lock ring422and barrel trunnion426cam the barrel extension flange430, and thus the entire barrel412, in place, holding it along an entire 360° arc which is more secure than prior art designs and automatically centers the barrel412in the trunnion426and therefore keeps the barrel centered adjacent the firing chamber. Lock ring422and barrel trunnion do not interface to the point of totally abutting each other, but instead leave a space440for the barrel flange430and for the barrel rod guide405to extend out of the barrel trunnion426. It should also be noted that lock ring422also provides a measure of heat sinking capability to the system to prolong use of the firearm without changing barrels.

In use, depicted inFIGS. 15a-15d, the barrel412is held by the lock ring422and trunnion426. The user unfolds the handle424and depresses the lock plunger (FIG. 11b). The user then rotates the handle424and associated lock ring422until it is freed from the trunnion426(FIG. 11c). At that point, the barrel412is removed from the trunnion426(FIG. 11d). It should be noted that the barrel412does not turn in this operation.

It should also be noted that the barrel trunnion426may be manufactured to accommodate any size, caliber, or type of rifle. As such, the barrel trunnion426may be manufactured to accommodate individual brand, model, and rifle specifications, including caliber, headspace.