ADAPTIVE BOLT CARRIER GROUP

FIELD OF THE INVENTION

[0001] The present invention relates to the field of firearms and more particularly relates to an adaptive bolt carrier group utilizing a firearm bolt for a platform different than one manufactured for said platform.

BACKGROUND OF THE INVENTION

[0002] There are many kinds of firearms. Many are popular with the gun owning public, others are not or have been discontinued. Sometimes, different weapons platforms utilize similar functionality to others and the similarities are enough that more popular components may be used directly with other platforms. However, this is rarely the case, especially with more engineered functional parts. There remains a possibility, though, that parts may be adapted to utilize the components of more conventional weapons. One example is the parity between the AR-15 platform and the AR- 18. The AR-15 is perhaps the dominant personal firearm platform in America and the part for it are readily made and found. The AR-18 is a lesser-known system with fewer spare parts available. Both were designed by ArmaLite (thus AR) in the 1950’s and 1960’s and utilize a 5.56 NATO (.223 Remington) caliber round and a cam twisted firing bolt to seal the firing chamber and the lock the firing bolt and firing pin in place. However, the systems are not generally compatible as the AR-15’s camming of the firing bolt occurs on top of the bolt carrier while the AR-18’s occurs on its side. The present invention is an adaptive bolt carrier group with a novel bolt carrier that will allow the use of a common AR-15 bolt in a lesser common AR-18 system.

SUMMARY OF THE INVENTION

[0003] In view of the foregoing disadvantages inherent in the known types of bolt carriers, an improved bolt carrier may provide a system that meets the following objectives: that it be able to utilize an AR-15 bolt with an AR-18 firearm and still allow the firearm to operate. As such, a new and improved bolt carrier group may GDMDB21A comprise an adaptive bolt carrier body with a specially placed upwards cam pin slot that is positioned away from other moving components to accomplish this objective. [0004] The more important features of the invention have thus been outlined in order that the more detailed description that follows may be better understood and in order that the present contribution to the art may better be appreciated.

Additional features of the invention will be described hereinafter and will form the subject matter of the claims that follow.

[0005] Many objects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

[0006] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for description and should not be regarded as limiting.

[0007] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To describe the manner in which the above- recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific example embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are therefore not to be considered as limiting of its scope, the invention will be GDMDB21A described and explained with additional specificity and detail using the accompanying drawings.

[0009] Figure 1 is a perspective view of an adaptive bolt carrier group.

[0010] Figure 2 is a partial section of an AR- 18 firearm utilizing the adaptive bolt carrier group of FIG. 1 .

[0011] Figure 3 is a perspective view of a prior art AR- 15 bolt carrier group.

[0012] Figure 4 is a perspective view of a prior art AR- 18 bolt carrier group.

[0013] Figure 5 is a, exploded view of the AR- 15 bolt carrier group of FIG. 3.

[0014] Figure 6 is an exploded view of the AR-18 bolt carrier group of FIG. 4.

[0015] Figure 7 is a series of perspective views illustrating the assembly if the adaptive bolt carrier group of FIG. 1 .

[0016] Figure 8 is a perspective view of a modified bolt carrier body according to one embodiment of the present invention.

[0017] Figure 9 is an alternate perspective view of the bolt carrier body of FIG. 8.

[0018] Figure 10 is an exploded view of the adaptive bolt carrier group of FIG. 1 .

[0019] Figure 11 is a left elevation of the adaptive bolt carrier group of FIG. 1 .

[0020] Figure 12 is another alternate perspective view of the adaptive bolt carrier group of FIG. 1 .

[0021] Figure 13 is a top plan view of the adaptive bolt carrier group of FIG. 1 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] With reference now to the drawings, a preferred embodiment of the adaptive bolt carrier group 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.

[0023] With reference to FIG. 1 , the adaptive bolt carrier group, when made for an AR-18 platform and an AR- 15 bolt, utilizes a modified bolt carrier manufactured to fit within the AR-18 platform (180) (FIG. 2) while utilizing an AR-15 bolt assembly (290). The AR-15 bolt carrier group (200) (FIGS. 3 and 5) features a bolt carrier (210) and a bolt carrier key (220) containing a bolt assembly (290). The bolt assembly (290) includes the firing bolt proper (230) with a mounted extractor (240) and gas rings (250). A cam pin (260) resides on an upper side of the bolt (230) and interacts with a helical slot in the bolt carrier (210) to twist the bolt (230) when it is GDMDB21A in a forward position in the firearm and lock it into place. The firing pin (270) resides coaxially within the bolt (230) and is retained in the assembly with a firing pin retaining pin. The bolt assembly (290) is removed from the AR-15 bolt carrier group (200) and simply fits inside the modified bolt carrier (110) for use in the AR-18 platform (FIG. 3). The AR-18 bolt carrier group (300) (FIGS. 4 and 6) utilizes many analogous parts, with a bolt assembly (390) including bolt (330), extractor (340), firing pin (370) and firing pin retention pin (380). What is different, however, is that the carrier (310) has a helical slot for the cam pin (360) on its side and a small handle (350) is featured on a side opposite. The upper portion of the carrier body (310) features two bores (320) to interact with two support rods in the AR-18 architecture and allow the bolt carrier group (300) to slide along said rods.

Otherwise, the bolt carrier group (300) of the AR-18 functions in the same manner as the bolt carrier group of the AR-15 - when the firing bolt advances to its forwardmost position, the bolt carrier (310) advances slightly further so that the cam pin (360) will interface with its helical cam slot and twist and lock the firing bolt (330) in the forward position. This common functionality is what allows the present invention to use the AR-15 bolt assembly in AR-18 architecture.

[0024] As shown in FIG. 7, the disclosed embodiment utilizes a modified AR-18 bolt carrier body (110) with the bolt assembly (290) (including the firing pin retaining pin) of the AR-15 bolt carrier group (200). As shown in FIGS. 8 and 9, the modified carrier body (110) features some of the same bores and holes as the original carrier: a bore for the firing bolt assembly (130), a hole for the retaining pin (140), a hole for the handle (150), and the rail bores (120a), (120b). However, along the upper left edge a chamber (170) is cut, in a manner to provide an ear for continuation of the interrupted rail bore (120b), so that a helical cam slot (160) may be cut into the firing bolt bore (130).

[0025] Assembling the system then (FIGS. 10-13) takes the AR-15 bolt assembly (290) and places it within the bolt carrier body (110), with the cam pin (26)0 being inserted through the cam slot (160). The firing bolt (27)8 and the retaining pin (280) are inserted in position. Handle (350) is then placed in position. This assembly therefore allows the use of the AR-15 bolt in an AR-18 firearm as the upwards cam pin (260) resides in a cam slot (160) that is removed from and will not interfere with GDMDB21A the sliding motion of the bolt carrier assembly when in use. Other similar systems may be adapted for each other in similar manner.

INDUSTRIAL APPLICABILITY [0026] The present invention has industrial applicability as it may be made in industry and has particular relevance and utility in the field of firearms.

[0027] Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred. Therefore, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.