Bolt action firearm

Abstract

Bolt action firearms have a frame, a bolt operable to move with respect to the frame between a rearward retracted position and a forward advanced position, the bolt operable when in the forward advanced position to rotate with respect to the frame between an unlocked position and a locked position, a trigger connected to the frame and movable between a released position and an actuated position, and a latch mechanism interfacing the bolt and the trigger and operable to enable movement of the trigger from the released position to the actuated position when the bolt is in the locked position and operable to prevent movement of the trigger from the released position to the actuated position when the bolt is in the unlocked position. The frame includes an upper receiver containing the bolt, and a lower receiver separable from the upper receiver and containing the latch mechanism and the trigger.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application Number 63 / 761,935 filed on February 22, 2025, entitled “BOLT ACTION PISTOL-CALIBER FIREARM,” which is hereby incorporated by reference in its entirety for all that is taught and disclosed therein.FIELD OF THE INVENTION

[0002] The present invention relates to firearms, and more particularly to a bolt action firearm that is a safe adaptation of the blowback-operated pistol-caliber AR-15 type firearm into a bolt action firearm.BACKGROUND AND SUMMARY OF THE INVENTION

[0003] Bolt-action firearms are good for suppressor shooting because they are simpler and more stable during firing, which minimizes noise and recoil. Since a bolt-action rifle has no blowback-operated action to cycle, more of the expanding gases are directed through the suppressor, as opposed to bleeding out of the ejection port, leading to greater sound reduction and a more predictable shooting experience.

[0004] Pistol-caliber AR-15 firearms are popular because of their modularity, affordability, and user-friendly design, which allow for extensive customization and easy adaptation for different uses like home defense, sport shooting, and hunting. Their popularity is also driven by lower recoil, compatibility with many accessories, and availability of parts and aftermarket support. However, conventional pistol-caliber AR-15 firearms are blowback-operated, which makes them less suitable for use with a suppressor.

[0005] Adapting a conventional blowback-operated pistol-caliber AR-15 firearm for bolt action operation creates a potential safety issue because the user could potentially slide the bolt forward and chamber a live round, without locking the bolt into battery. This same condition could happen if during carry and use the bolt were to become unlocked and the firearm still had a live round chambered. Either way, the hammer is cocked, and if the user were to pull the trigger, the round would be fired without the bolt being locked into battery. This would cause a catastrophic failure and potential injury or death.

[0006] Therefore, a need exists for a new and improved bolt action firearm that is a safe adaptation of the blowback-operated pistol-caliber AR-15 type firearm into a bolt action firearm. In this regard, the various embodiments of the present invention substantially fulfill at least some of these needs. In this respect, the bolt action firearm according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of safely adapting the blowback-operated pistol-caliber AR-15 type firearm into a bolt action firearm

[0007] The present invention provides an improved bolt action firearm, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide an improved bolt action firearm that has all the advantages of the prior art mentioned above.

[0008] To attain this, the preferred embodiment of the present invention essentially comprises a frame, a bolt operable to move with respect to the frame between a rearward retracted position and a forward advanced position, the bolt operable when in the forward advanced position to rotate with respect to the frame between an unlocked position and a locked position, a trigger connected to the frame and movable between a released position and an actuated position, and a latch mechanism interfacing the bolt and the trigger and operable to enable movement of the trigger from the released position to the actuated position when the bolt is in the locked position and operable to prevent movement of the trigger from the released position to the actuated position when the bolt is in the unlocked position. The frame includes an upper receiver containing the bolt, and a lower receiver separable from the upper receiver and containing the latch mechanism and the trigger. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims attached.

[0009] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a top isometric view of the current embodiment of a bolt action firearm constructed in accordance with the principles of the present invention.

[0011] FIG. 2 is an exploded view of the bolt action firearm of FIG. 1.

[0012] FIG. 3 is an exploded view of the lower receiver of the bolt action firearm of FIG. 1.

[0013] FIG. 4 is an exploded view of the bolt body of the bolt action firearm of FIG. 1.

[0014] FIG. 5 is a rear isometric view of the bolt lug of the bolt action firearm of FIG. 1.

[0015] FIG. 6 is a rear isometric view of the bolt body of the bolt action firearm of FIG. 1.

[0016] FIG. 7 is a rear isometric view of the trigger of the bolt action firearm of FIG. 1.

[0017] FIG. 8 is a top isometric view of the latch mechanism of the bolt action firearm of FIG. 1.

[0018] FIG. 9 is an exploded view of the latch mechanism of the bolt action firearm of FIG. 1.

[0019] FIG. 10 is a top isometric partial view of the lower receiver of the bolt action firearm of FIG. 1.

[0020] FIG. 11 is a top isometric view of the upper receiver of the bolt action firearm of FIG. 1.

[0021] FIG. 12 is an isometric sectional view of the upper receiver of the bolt action firearm of FIG. 1.

[0022] FIG. 13A is a right side cutaway view of the upper and lower receivers of the bolt action firearm of FIG. 1 showing the latch mechanism installed in the bolt action firearm with the bolt in the unlocked position and the trigger in the released position.

[0023] FIG. 13B is right side cutaway view of the upper and lower receivers of the bolt action firearm of FIG. 1 showing the latch mechanism installed in the bolt action firearm with the bolt in the locked position and the trigger in the released position.

[0024] FIG. 13C is a right side cutaway view of the upper and lower receivers of the bolt action firearm of FIG. 1 showing the latch mechanism installed in the bolt action firearm with the bolt in the locked position, the trigger in the actuated position, and the hammer in the fired position.

[0025] The same reference numerals refer to the same parts throughout the various figures.DESCRIPTION OF THE CURRENT EMBODIMENT

[0026] An embodiment of the bolt action firearm of the present invention is shown and generally designated by the reference numeral 10.

[0027] FIGS. 1&2 illustrate the improved bolt action firearm 10 of the present invention. More particularly, the bolt action firearm 10 has a frame 12 and a bolt 14 operable to move with respect to the frame between a rearward retracted position and a forward advanced position. The bolt is operable when in the forward advanced position to rotate with respect to the frame between an unlocked position and a locked position. The bolt defines a bolt rotation axis 16. A trigger 18 is connected to the frame and is movable between a released position and an actuated position. A latch mechanism 20 interfaces the bolt and the trigger and is operable to enable movement of the trigger from the released position to the actuated position when the bolt is in the locked position and operable to prevent movement of the trigger from the released position to the actuated position when the bolt is in the unlocked position. The frame includes an upper receiver 22 containing the bolt, and a lower receiver 24 separable from the upper receiver and containing the latch mechanism and the trigger.

[0028] FIG. 3 illustrates the improved lower receiver 24, receiver extension 26, ejector 28, and magazine well insert 30 of the present invention. More particularly, the lower receiver defines a magazine well 32 that is sized for large-framed pistol magazines such as double stacked .45acp magazines. To be able to use smaller pistol magazines, such as 9mm or .380acp magazines, the magazine well insert is slid into the top 34 of the magazine well from the top. The magazine well insert is prevented from sliding out the bottom of the lower receiver by a protrusion 36 that stops against a shelf (not visible) in the lower receiver. The magazine well insert is held in place by the ejector. The ejector interfaces with a groove 38 defined by the top rear of the magazine well insert. The ejector is affixed in place with two screws (not shown) through the side or in a slot 40 defined by the top 42 of the lower receiver. The ejector could also be affixed with two screws from the top, or two roll pins going through the lower receiver transversely, or a combination of any of these.

[0029] FIGS. 4&6 illustrate the improved bolt body 44 of the present invention. FIG. 5 illustrates the improved bolt lug 46 of the present invention. More particularly, the bolt lug is pivotally attached to the bolt body by a pivot pin 48, which is secured to the bolt body by a cross pin 50, to form the bolt 14. A spring-loaded detent 52 (shown in FIG. 2) is received in a bore 54 defined by the bolt lug (also shown in FIG. 2). The spring-loaded detent mates with one of two dimples 56, 58 defined by the bolt body. The spring-loaded detent and the spring pushing the spring-loaded detent (not shown) are captive in the bolt lug and are held in with a grub screw (not shown) from the rear. Another way that a spring-loaded detent could interact with the bolt lug is that the detent could be located in the upper receiver 22 and interact with dimples on the cylindrical surface 62 of the bolt lug. In such an iteration, the dimples would correspond to the locked and unlocked positions of the bolt lug.

[0030] The bolt lug 46 defines a cam surface 60. The cam surface has a varying radius from the bolt rotation axis 16 in the current embodiment. The bolt lug has an exterior cylindrical surface 62 defining a cam channel 64 that includes the cam surface. The cam channel is L-shaped in the current embodiment. The bolt lug also includes two locking lugs 66, 68 that lock into the upper receiver 22 when the bolt lug is rotated 60° about the pivot pin 48 between the unlocked position and the locked position. The two dimples 56, 58 correspond to the locked and unlocked positions of the bolt lug.

[0031] The bolt body 44 defines a channel 70 running along the top 72 of the bolt body. The channel mates with a tab 74 (shown in FIG. 2) that protrudes into the upper receiver 22. The interaction between the channel and the tab keeps the bolt body from rotating as the bolt 14 moves between the rearward retracted position and the forward advanced position, and as the bolt lug 46 is rotated between the locked and unlocked position. For this channel feature to be possible, the pocket for hammer clearance 76 does not go all the way through the bolt body from top to bottom as is the case in a traditional AR-15 type firearm.

[0032] FIG. 7 illustrates the improved trigger 18 of the present invention. More particularly, the trigger has a rear end 78 including an upward facing stop surface 80. The trigger defines a transverse groove 134 defining the upward facing stop surface. Alternately, an aperture could be used in place of the transverse groove with a matching protrusion on the forward portion of stop element 116 that would protrude into the aperture when in the forward position. The lower receiver 24 includes a protrusion 82 (shown in FIG. 2). The trigger defines an aperture 84 configured to receive the protrusion. The protrusion is permanently inserted into a hole 148 (shown in FIGS. 13A-C) in the lower receiver to ensure the user cannot install a standard trigger, which would create the unsafe conditions regarding an unlocked bolt combined with a chambered live round previously described because a standard trigger would lack the features to interact with the latch mechanism 20.

[0033] FIGS. 8&9 illustrate the improved latch mechanism 20 of the present invention. FIG. 10 illustrates the rear of the improved lower receiver 24 of the present invention. More particularly, the latch mechanism includes a latch housing 86 separable from the frame 12 containing the latch mechanism. The latch housing splits into two halves in the current embodiment. The latch mechanism is received within a pocket 88 defined by the rear of the lower receiver. The pocket includes steps 90 that correspond to steps 92 defined by the latch housing. The lower receiver has deliberate design differences to ensure there is not any compatibility between the lower receiver and a standard AR-15 upper receiver, or a standard AR-15 lower receiver and the frame. The two main differences are the placement of the rear takedown pin hole 130 (shown in FIG. 3), and the overall geometry on the top of the lower receiver. These changes eliminate the possibility of a user assembling a bolt action AR-15 style firearm without including the latch mechanism, which is crucial for safe handling and use of this type of firearm.

[0034] The latch mechanism 20 includes a follower 94 that interfaces the cam surface 60 defined by the bolt lug 46. The follower is a reciprocating element that reciprocates perpendicularly to the bolt rotation axis 16 in the current embodiment. The cam surface engages the follower when the bolt lug 46 rotates into the locked position. During that rotation, the cam surface pushes the follower down. The follower defines ears 96, 98 that are received in slots 100, 102 defined by the latch housing to prevent rotation of the follower.

[0035] The bottom of the follower 94 defines an angled surface 104 that engages a first end 106 of a link 108. The link is an elongated, pivoting element having an intermediate portion 110 that defines a link pivot axis 112. The intermediate portion defines an aperture 114 that receives a pin 136 that also passes through the latch housing 86 to hold the link in position and enable the link to pivot. The latch mechanism 20 includes a stop element 116 movable between engagement with and disengagement with the upward facing stop surface 80 on the trigger 18. The stop element defines ears 138, 140 that are received in slots 142, 144 defined by the latch housing to prevent rotation of the stop element. The stop element engages an opposed second end 118 of the link. Thus, the latch mechanism includes a first latch element 94 (the follower) interfacing the bolt 14 via the cam channel 64 in the bolt lug 46, a second latch element 116 (the stop element) interfacing the trigger 18, and a link 108 interfacing the first latch element and the second latch element. The first latch element moves in a first direction, and the second latch element moves in a different second direction in the current embodiment. The first latch element is spring biased toward the bolt via a spring 120 that pushes the stop element forward, which pivots the link to urge the first end of the link upwards under spring tension.

[0036] When the link 108 pivots after the bolt 14 is placed in the locked position to push the follower 94 down, the opposed second end 118 of the link pulls back on the stop element 116, disengaging the stop element from the upward facing stop surface 80 on the trigger 18. This enables movement of the trigger from the released position to the actuated position to discharge the bolt action firearm 10.

[0037] FIGS. 11&12 illustrate the improved upper receiver 22 of the present invention. More particularly, these illustrations show how the bolt lug 46 locks into the frame and where the tab 74 is located. The tab is held in place by the picatinny rail 120 (shown in FIG. 2) that is attached to the upper frame via screws (not shown). The tab can also be welded into place on the outside of the frame. The upper receiver defines locking surfaces 122, which are recesses that the locking lugs 66, 68 on the bolt lug engage with when the bolt lug is in the locked position. The upper receiver also defines an aperture 124 that vents gas in the event of a ruptured case or punctured primer. This aperture corresponds to a relief cut 126 on the front of the bolt body 44 (shown in FIG. 6). The bottom of the upper receiver also defines an aperture 146 that receives the top, cylindrical portion of latch housing 86 to isolate the follower 94 from the frame to avoid friction caused by tolerance stack or misalignment.

[0038] FIGS. 13A-C illustrate the improved latch mechanism 20 of the present invention in its two stages of operation. More particularly, FIG. 13A shows the bolt 14 in the unlocked position, thus out of battery. The follower 94 is in the upward position, the link 108 is in the counterclockwise position, and the stop element 116 is in the engaged or forward position. The stop element is engaged with the upward facing stop surface 80 on the trigger 18, which prevents movement of the trigger from the released position to the actuated position to discharge the bolt action firearm 10.

[0039] FIG. 13B depicts the bolt lug 46 of the bolt 14 having rotated into the locked position. This has caused the cam surface 60 to push the follower 94 into the down position. This action has pivoted the link 108 in the clockwise direction, which has disengaged the stop element 116 from the upward facing stop surface 80 on the trigger 18. Assuming the other safety on the bolt action firearm 10 is in the “fire” position, (the standard AR-15 safety 132, shown in FIG. 2) the trigger is now able to be pulled, and the hammer 128 released, thus firing the bolt action firearm. FIG. 13C depicts the status of the bolt action firearm after discharge. The bolt lug, follower, link, and stop element remain in the same position as FIG. 13B, but the trigger has been pulled, and the hammer has been released to discharge the bolt action firearm.

[0040] In the context of the specification, the terms “rear” and “rearward,” and “front” and “forward,” have the following definitions: “rear” or “rearward” means in the direction away from the muzzle of the firearm while “front” or “forward” means it is in the direction towards the muzzle of the firearm.

[0041] While a current embodiment of a bolt action firearm has been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. Although rifles have been disclosed, the bolt action firearm is also suitable for use with shotguns, light and medium machine guns, and other firearms. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

[0042] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

1. A firearm comprising:a frame;a bolt operable to move with respect to the frame between a rearward retracted position and a forward advanced position;the bolt operable when in the forward advanced position to rotate with respect to the frame between an unlocked position and a locked position;a trigger connected to the frame and movable between a released position and an actuated position; anda latch mechanism interfacing the bolt and the trigger and operable to enable movement of the trigger from the released position to the actuated position when the bolt is in the locked position and operable to prevent movement of the trigger from the released position to the actuated position when the bolt is in the unlocked position.

2. The firearm of claim 1 wherein the frame includes an upper receiver containing the bolt, and a lower receiver separable from the upper receiver and containing the latch mechanism and the trigger.

3. The firearm of claim 1 wherein the bolt defines a bolt rotation axis, and defines a cam surface of varying radius from the bolt rotation axis, and the latch mechanism includes a follower interfacing the cam surface.

4. The firearm of claim 3 wherein the bolt has an exterior cylindrical surface defining a cam channel including the cam surface.

5. The firearm of claim 3 wherein the cam channel is L-shaped.

6. The firearm of claim 3 wherein the follower is a reciprocating element.

7. The firearm of claim 3 wherein the follower reciprocates perpendicularly to the bolt rotation axis.

8. The firearm of claim 1 wherein the trigger has a rear end including an upward facing stop surface, and wherein the latch mechanism includes a stop element movable between engagement with and disengagement with the upward facing stop surface.

9. The firearm of claim 8 wherein the trigger defines a transverse groove defining the stop surface.

10. The firearm of claim 1 wherein the latch mechanism includes a first latch element interfacing the bolt, a second latch element interfacing the trigger, and a link interfacing the first latch element and the second latch element.

11. The firearm of claim 10 wherein the first latch element moves in a first direction and the second latch element moves in a different second direction.

12. The firearm of claim 10 wherein the link is a pivoting element.

13. The firearm of claim 10 wherein the link is an elongated element having a first end interfacing the first latch element and an opposed second end interfacing the second latch element.

14. The firearm of claim 13 wherein the link has an intermediate portion defining a link pivot axis.

15. The firearm of claim 10 wherein the first latch element is spring biased toward the bolt.

16. The firearm of claim 1 including a latch housing separable from the frame and containing the latch mechanism.

17. The firearm of claim 2 wherein the lower receiver includes a protrusion and wherein the trigger defines an aperture configured to receive the protrusion.

Images