Firearms, Systems, and Methods for Quick Connection of a Barrel to a Firearm

This application claims the benefit of and priority to, U.S. Provisional Patent Application Ser. No. 63/643,081 filed on May 6, 2024 for AR Nexus Quick Barrel Change Rifle System, incorporated herein by reference in its entirety for continuity of disclosure.

Various types of firearms utilize barrels that are replaceable or interchangeable. A user may wish to replace a barrel of a rifle, for instance, to enable a change of caliber of ammunition used with the firearm, or to provide replacement of damaged barrels, or to use barrels of different lengths for different tactics, or for other reasons. Various rifles and mechanisms have been developed to attach/detach a barrel from the firearm, and for which patents have been filed or granted, such as those in U.S. Pat. Nos. 8,782,943, 9,423,194, and US Patent Application Publications US2017/0160037, US 2020/0158460, US 2021/0278169, US 2022/0178632, US 2015/0308779, and 2015/0007478, among perhaps others. While such rifles and mechanisms may have benefits, there is room for improvement.

The invention allows for easy exchange of barrels of a firearm. The invention includes firearms or firearm components having mechanisms to connect a variety of different barrels or barrel systems to the firearm or components. An AR-15 style of firearm is one example and includes a barrel inserted into an upper receiver having a spring cavity, a hand guard configured to pass along the barrel and configured to mate with the upper receiver, and a spring configured to fit into the spring cavity to abut the hand guard to secure the barrel to the upper receiver. In aspects the barrel includes a rim where an end of the hand guard abuts the rim. In further aspects the firearm or component receives a pin having a non-circular cross section which is rotated to abut tines of the spring which straddle the barrel and secure the barrel to the upper receiver. A variety of types of barrels may be used with the AR-15 style of firearm, and it may be appreciated that different firearms, other than AR-15 varieties, may also be configured to receive different barrels or barrel assemblies in accordance with aspects of the invention. Firearms other than AR-15 style may also utilize the features of the invention.

In further aspects the invention includes a system for quick connection of a barrel to a firearm where a receiver is configured to receive the barrel and a spring positioned within the receiver is configured to straddle the barrel where a cam is configured to abut the spring and secure the barrel within the receiver when the cam is turned. In aspects the system may also include a hand guard positioned over the barrel and abutting a rim of the barrel within the receiver where rotation of the cam causes the spring to force against the hand guard which in turn presses against the rim to secure the barrel within the receiver.

In a further aspect the system includes a firearm component having an upper receiver defining a bore passing from a stock end through to a barrel end, the bore defining a central axis, the upper receiver configured to receive a barrel of a firearm and a cam oriented transvers the central axis where activation of the cam locks into the upper receive a barrel which may be inserted therein. In aspects the component includes a pin having a non-circular cross-sectioned portion where rotation of the pin locks into the upper receiver the barrel which may be inserted therein.

In further aspects the invention includes a method of assembling a firearm having a receiver, including inserting a barrel into the receiver, the barrel having a rim and a bore defining a central axis through the barrel, and rotating, within the receiver, a pin having a non-circular cross-section, the pin oriented transverse the central axis such that rotation of the pin locks the rim and barrel into the receiver. In aspects the method includes positioning a hand guard over the barrel and into the receiver where rotation of the pin applies force to the hand guard which in turn applies force to the rim to lock the barrel into the receiver. In aspects the method includes insertion of a spring into the receiver where the spring straddles the barrel and rotation of the pin applies force to the spring which in turn applies force directly to the rim or to the handguard and then to the rim to lock the barrel.

The above partial summary is not intended to describe each illustrated embodiment, aspect, or every implementation of the present invention. The figures and detailed description and claims that follow more particularly exemplify these and other embodiments and further aspects of the invention.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not necessarily to limit the invention to the particular embodiments, aspects and features described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention and as defined by the appended claims.

Referring toaspects of the firearms, firearm components, systems and methods of the invention are shown.shows one aspect of a firearm. The firearmmay be of a rifle, or of an automatic rifle variety, or of a semi-automatic or single fire variety, or any weapon utilizing a barrel affixed to a receiver, including but not limited to breach load weapons, muzzle loaders, shotguns, mortars, recoilless rifles, cannons, light and heavy machine guns, and handguns. Firearmas shown inis of an AR-15 variety and includes a hand guardconnected to an upper receiverwith a barrelextending from the upper receiverand hand guard. The upper receiver is connected to a lower receiver. The lower receiverincludes a shoulder stock, a hand gripand trigger. In aspects, a magazineinserts into a magazine port′ (See) of lower receiver. Magazineholds ammunition. In one aspect a charging handleand a bolt carrier groupinsert into a stock endof the upper receiver.andshow firearmin an exploded view, with barrel assemblyseparated from the upper receiverand separated from the hand guard. As explained herein, the barrel assemblymay be quickly and easily connected to and removed from the firearm, and a variety of different types of barrels or barrel assembliesmay be exchanged or replaced with the firearmas desired. It may be appreciated that a variety of types of barrelsmay be used with the AR-15 style of depicted firearm, and that different firearms, other than AR-15 varieties, may also be configured to receive different barrels or barrel assemblies.

is a perspective view of a representative barrel assemblyfor use with firearmand firearm component. Barrel assemblyincludes a barrelhaving a tubular-shaped bodyhaving a borerunning therethrough. Boredefines a central axis along line A-A of. Ammunition is fired through the boreof the barrelas is common. In one aspect barrel assemblyincludes a gas tubewhich is commonly used in or with barrelsof an automatic or semi-automatic rifle variety. While the firearmdepicted inis of an AR-15 or similar variety showing a gas tube, a gas tubeis not always desired or required, such as when attaching a barrelwithout a gas tube and instead with a bolt action mechanism or other mechanisms. Firearms use many different mechanisms to load, shoot, and reload the ammunition, and a majority of such firearms, when using the components, systems and methods represented in this AR-15 example can be reconfigured to allow a user to quickly and easily swap barrels.

In one aspect the gas tubeextends beyond a terminal end of the tubular body, opposite the output end of the barrel assembly. The gas tubeinserts into a companion tube within the upper receiverto accommodate flow of gas. Barrel assemblyor barrelincludes a rimor annular structure positioned about the tubular bodyof barrel. Barrel assemblyor barrelincludes a chamber housing′ comprising a huband taperextending from the tubular body. Barrel extensionextends from the chamber housing′. The rimis positioned between barrel extensionand chamber housing′. A barrel indexing pinis positioned at barrel extension adjacent or abutting rim. Indexing pinis configured to insert into a socket (barrel pin slot) within upper receiver. It is standard in the AR-15 industry that all barrel assembliesor barrelsinclude a collar or rimand a barrel extensiontogether with a barrel indexing pin. Such standard or common configurations allow the same to be universally interchanged among various firearms. The barrel assembliesor barrelsmay be of particular Mil-Spec or military specifications. The Mil-Spec barrel assemblies or barrelswork together with other Mil-Spec components of the AR-15 variety or other types of weapons and firearms. In one example, collar or rimhas a diameter greater than one inch, and in some cases has a diameter of 1.17 inches or 29.7 mm, and barrel indexing pinraises upward about 0.12 inches or 3.05 mm from the barrel extension. In one aspect barrel extensionhas a diameter of 1.00 inches and a length of 1.25 inches. In one aspect the distance from a terminal end of the barrel extensionto the barrel indexing pinmeasures 0.8645 inches, or 21.958 inches. In aspects the barrel indexing pin, collarand barrel extensionstructure of AR-15 firearm barrelsare the same while the remaining aspects of the tubular bodyand barrelmay be configured to accommodate a variety of types of ammunition by having varying bore diameters and structures and lengths. Such different barrel assemblies, barrelsand tubular bodiesmay be configured to accommodate a variety of types of ammunition, including barrelsused to fire ammunition including but not limited to .350 Legend, .300 Blackout, 5.56 NATO, .223 Wylde, 7.62×39, 6.5 Grendel, 9 mm, .45 ACP, .40 S&W .22 LR and Magnum, .450 Bushmaster, .458 SOCOM, .224 Valkyrie, among others. Barrelmay also vary in length, such as 7.5 inches for an AR-15 pistol to 24+ inches for a rifle. Barrel assemblyor barrelmay also have a much shorter length when used in a hand gun variety of firearm. Barrel assemblyor barrelmay be made of metal or composites of metal, including but not limited to 410 and 416 stainless steel or 4140 and 4150 carbon steel.shows gas tubeextending rearward from the rifled barrel. The gas tubeinserts into the upper receiverto pass through or into a receiving channel therein (See also,,). The barrel indexing pininserts into a corresponding opening within the receiverand assists with proper and efficient alignment of the barrel assemblyor barrelwithin the receiver. The barrel indexing pinalso causes the barrel assemblyto resist rotation once set within the receiver.

show various stages of assembly of firearmand/or firearm component, including methodsof assembly.is an exploded view of firearm componenthaving an upper receiver, hand guardand spring. The firearm componentis configured to receive a variety of types of barrel assembliesor barrels, which may be easily and quickly connected to componentand replaced with a different barrelor barrel assembly.shows upper receiverwith a barreland/or barrel assemblyinserted in a barrel endof receiver. A springis poised to be inserted into the receiver to secure the barrelinto position. A pininserts into the receiver to lock the barrelinto the receiver, as explained in further detail below.shows hand guardpoised to be secured to upper receiver, with barrelextending outward through an output endof the hand guard. The hand guardis also locked into position with the receiver, as explained in further detail below.

present various close-up views of upper receiver. In aspects, receiverincludes a generally tubular bodyhaving a cavity or bore extending from a barrel endthrough to a stock end. A spring cavityis defined with an opening at a top portion of the receivertoward or at the barrel end. An ammunition portis located at an underside of the receiverand is configured to receive ammunition such as ammunition from the magazine. The stock endof the upper receiveris configured to receive the charging handleand bolt carrier group. Receiverincludes a pivot′ having a hole which receives a pivot pinof the lower receiver(Seeand) which allows upper receiverto pivot upwards from lower receiverto expose the openings for receiving the charging handleand bolt carrier group. At barrel endthe upper receiverincludes a receiver headand receiver foot. The spring cavityforms a gap between receiver headand the rearward portion of barrel end. A receiver footis positioned below receiver head. Receiver footincludes a face′ which mates with hand guard. An alignment ribA extends from face′ to assist in alignment and structural support of the hand guard. An alignment ribB is positioned at receiver headto also mate with hand guardto accommodate alignment and structural support and mating of the components. Receiverincludes a pin holewhich passes transverse the generally oriented bore through the receiver, and is configured to receive a locking pinas described below. Upper receiveris made of metal, such as aluminum or steel or other metal, and may also be made of other materials or composites or alloys. Receiverdefines a bore′ in which is inserted the barrel assemblyand/or barreland a portion of the hand guardas described herein. Bore′ defines a central axis along line B-B of. It may be appreciated that in aspects central axis of bore′ of receiveraligns along central axis of boreof barrel.

present various close-up views of hand guard. In aspects, hand guardincludes a generally tubular bodydefining a bore running therethrough. Hand guardincludes a receiver endwhich connects to the upper receiverand an output endthrough which the bore is aligned. At the receiver endis a connecting portionfor connecting the hand guardto the upper receiver. The connecting portionextends from mating wallof tubular bodyand includes a tubular-like shaped neckfollowed by a collarwhich in one aspect is a partial annular ring having diameter greater than a diameter of the neck, followed by a headhaving a terminal end′. Headis also tubular-like shaped having a diameter smaller than a diameter of the annular-like ring or collar. Connecting portioninserts into the bore′ (See) of upper receiver. A gap′ is defined by the connecting portionto allow clearance for portions of the barrel assembly, such as clearance for the gas tube, when hand guardis inserted over the barreland within receiver. Particularly, the gap′ is defined in part by an upper aspect of the neck, collarand head. Collaris positioned at the connecting portionin a spaced relation from mating wall. The space between collarand mating wallallows for insertion of receiving springas further described herein. In one aspect mating wallmay also include alignment grooveA. An additional alignment grooveB is defined by upper mating wall′. Mating wallis configured to abut and mate with receiver footat face′ of receiver, with alignment grooveA receiving alignment ribA. Upper mating wall′ is configured to abut and mate with receiver head, with alignment grooveB receiving alignment ribB. Such mating enhances the quick alignment and stable connection between hand guardand receiver, and inhibits twisting between those components. The alignment features also allow for quick, confident and precise insertion of the hand guardonto the receiverfor proper alignment. In one aspect hand guardis a unitary component made of a single material such as metal, and may also be made of other materials including metal alloys, plastics or combinations of materials. In some aspects hand guardmay include ventilation apertures and a variety of gripping ribs which also assist in dissipation of heat and handling of the firearm.

present various close-up views of springand pin. As shown in, springis generally U-shaped having a pair of tines,extending from a base. The tines,define a barrel gapwhich allows springto insert into spring cavitywhile straddling hubof barrel. In one aspect tines,are spaced apart 1.25 inches or 31.75 mm, and extend about 1 inch from base. Springfurther defines a tube gapconfigured to provide clearance from the gas tubewhen the spring is inserted into the upper receiverat spring cavity. Springincludes a pair of finger wingsto accommodate finger gripping of the springfor easy insertion and removal of the springfrom the upper receiver. Once inserted, the finger wingsof the springextend partially outward (See) from an upper aspect of the bodyof the upper receiver. In one aspect springhas a thickness of about 0.125 inches or about 3.174 mm. In aspects, springis a leaf spring. Springis made of spring steel, which allows for flexing of springwith memory for return to its original form.

show a cam or pinwhich is configured to insert into pin holeof upper receiver. Cam or pinoperates as a cam to press against springas described in further detail below. In one aspect, pinhas a generally cylindrical bodyhaving a pin headat one end and a pin grooveat an opposite end of the body. In one aspect, pin bodyincludes a flattened portion. Pin headdefines a pin borethrough which may be inserted an object to help turn the pin to apply or release pressure on the spring. Pin grooveis configured to receive a retainer clip, spring clip, C clip washer or other retainer to secure pininto position. Pin slotis used as an indicator to clearly designate that the cam pinis in position to apply pressure to the springand lock all parts together or release pressure on the springfor disassembly. In one aspect pin slotaligns with or corresponds with flattened portion, so that when camis inserted within upper receiver, a user will appreciate the orientation or positioning of the flattened portionby viewing the orientation or position of the pin slot. In further aspects, upper receiverincludes indicia or graphics(See,) to assist a user in determining if the camis in a locked or unlocked position, i.e., if the pin slot aligns with indiciashowing an unlocked lock graphic, the operator will appreciate the pinis in the unlocked position (with the flattened portionfacing the springand applying zero or minimal pressure to the spring). Likewise, if the pin slotaligns with indiciashowing a locked lock graphic, the operate will appreciate the pinis in the locked position (with the flattened portionfacing other than toward the springso that the remainder of the pin bodyis applying force to the spring.

andshow various cross-section views of firearm, components, systems and method aspects of the invention.is a partial section view taken along a longitudinal center line, or line-, of. The barrel assemblyand/or barrelhas been inserted into the upper receiver, with the hand guardinserted over the barrelwhere the hand guardis also secured into the upper receiver. Particularly shown with respect to, pinis inserted into receiverwith the flattened portionfacing toward the stock endof the upper receiver. Springis inserted into spring cavityand tines,straddle the hubof the barrel. The tines,extend downward and are configured to abut against collar, which in turn abuts against rimof barrel assemblyor barrel. The pinmay be inserted prior to insertion of barrel, and prior to insertion of hand guardand prior to insertion of spring, or at any time after insertion of those items. When inserting pinprior to spring, it may be necessary to orient the flattened portiontoward the stock endof the upper receiverin order to have clearance for the insertion. In some cases, and in order to insert the spring into the receiver, the flattened portionshould also be oriented to face the stock endto allow for clearance.shows the springinserted into the spring cavitywhile the flattened portionof pinis facing the stock endof upper receiverand also facing the tines,(tineis hidden from view on this cross-section taken through tine). A small gap or clearance “C” is shown between tineof the springand collarof the hand guard. Thus, there is no pressure exerted by the springagainst the hand guardor barrel assembly.is a partial section view taken along the midline or longitudinal section of line-of. The tineof springis shown to abut against collar. Notice there is no clearance “C” between tineand collar. Rotation of the pinin a clockwise manner causes the pin bodyto press against the spring(i.e., the non-flattened portionof pinpresses against the tines,) to lock the barrel assemblywithin the upper receiver. Particularly, rotation of pincauses a camming action due to the increased diameter of the pinabutting against the spring. Turning the pin head(whether clockwise or counter-clockwise) causes the pin bodyto turn and press against the spring, thereby causing the collarof the hand guardto press against and retain the rimof the barrelin position. More particularly, rotation of pincauses tines,to press against the inward face′ of the hand guard, which in turn causes the terminal end′ of the headof the hand guardto press against the rimof the barrel. Such rotation of the camlocks the barrelinto the upper receiver. The barrelcannot be removed unless the camis rotated to allow removal of the springand removal of the hand guard. The camis oriented transverse the central axis of the boreof the barrel. In one aspect the camrotates along an axis perpendicular the central axis of the boreof the barrel. In aspects, the pinholedefines a central axis therethrough which is perpendicular the central axis of the bore′ and the central axis of the bore. The central axis defined by pinholeis positioned below the central axis of bore′. It may be appreciated that cammay operate as a cam with other than a flattened portion, such as where a cross-section of the pin bodyis other than circular, including but not limited to a cross-section that is eccentric, oblong, or other varying function.

In one aspect operation of the camsimultaneously locks into position the hand guardand the barrel. In other aspects it may be appreciated that use of cam(or multiple cams) may be alternatively configured to lock in either the hand guard, or the barrel, independently (with or without a spring). In further aspects, the cammay be oriented generally horizontally as shown in, or alternatively vertically, and springmay be inserted vertically, or alternatively sideways or laterally. In other aspects springand cammay be inserted in different orientations provided the camabuts against the springwhich in turn operates to apply a force against the rimof an inserted barrelor barrel assembly. Configuring springwith tines,to straddle the barrelso that pinabuts both tines,accommodates a more uniform securing force to lock the barrelinto the receiver.

In further aspects, a cam pinis configured to abut directly against the collar or rimof the barrelto secure the barrelwithin an upper receiver. In yet further aspects, where a barrelor barrel assemblyincludes a groove or grooves (unlike a projection or rim), a springor cam pinis configured to abut within the grooves of the barrel, such that pressure applied via the springor cam pinlocks the barrel into the receiver.

In a further aspect, and with reference again to, and, the invention includes a methodof securing a barrelto an upper receiverof a firearm. In one aspect the method includes the stepof inserting a barrelinto the barrel endof the upper receiver, the upper receiver having an elongated body defining a bore passing from the stock endthrough to the barrel end, the bore′ defining a central axis B, and the stepof activating the cam, which camis oriented transverse the central axis. Activation of the camlocks the barrelinto the upper receiver. In further aspects, a method of securing the barrelincludes insertion of a hand guardover the barreland into the barrel endof the receiver, and thereafter inserting the springin the direction of arrow A shown ininto the spring cavityof receiversuch that springabuts both camand collar. A further step includes rotating the cam to apply force to the springwhich applies force to the collarto secure against the rimand lock the barrelwithin the receiver. In further aspects, the barreland/or barrel assemblymay be quickly removed by rotating the camsuch that camno longer applies a force to the barrel, and then removing the barrel and replacing it with the same barrel or a different barrel′. In aspects, when rotating the camsuch that it no longer applies a force includes rotating the camso that it does not press against the spring, thus allowing removal of the springfrom the receiver, after which the hand guardmay be removed, and then removal and replacement of the barrel. Additional method aspects or variations thereof may be appreciated based on the above description of the firearm, components and systems herein.

In further aspects the invention includes a system for quick connection of a barreland/or barrel assemblyto a firearm, including an upper receiverhaving a barrel endand a stock endand a bore′ running therethrough. The system includes a barrelinserted into the barrel endand a hand guardpassed over the barreland also inserted into the barrel end. A cam or pinis inserted into a pin holeof the receiver. A spring is inserted into a spring cavityof the receiver adjacent the camand a collarof the hand guard. The collarabuts a rimof the barrel. Rotation of the pincauses pressure on the springwhich in turn presses against the collarwhich presses against the rimto lock the barrelinto the receiver.

It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.