FIREARM BOLT ASSEMBLY FOR A SELF-LOADING FIREARM

Abstract

A firearm bolt assembly for a self-loading firearm has an elongated frame defining a frame axis, a bolt connected to a forward end of the frame, a plurality of separate weights connected to the frame, and the weights being movable at least slightly with respect to the frame and to each other for movement along the axis. There may be a resilient spacer element between adjacent weights. There may be a resilient spacer element between one of the weights and a portion of the frame. The spacer element may be an O-ring. The weights may be connected to a rear portion of the frame. The weights may be tubular bodies each defining a bore. A portion of the frame may be received within the bore. The frame may define a rear portion having a first diameter, and a flange forward of the rear portion having a larger second diameter.

Claims

1. A firearm bolt assembly for a self-loading firearm comprising: an elongated bolt carrier frame defining a frame axis; a forward end of the frame being adapted to receive a bolt; a plurality of separate weights connected to the frame; a toroidal elastomeric ring positioned between each of the weights; and the weights being movable at least slightly with respect to the frame and to each other for movement along the axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a right side view of the current embodiment of the firearm bolt assembly for a self-loading firearm installed in a firearm.

[0013] FIG. 2 is a front isometric view of the current embodiment of the firearm bolt assembly for a self-loading firearm constructed in accordance with the principles of the present invention.

[0014] FIG. 3 is an exploded view of the firearm bolt assembly for a self-loading firearm of FIG. 2.

[0015] FIG. 4 is a right side view of the firearm bolt assembly for a self-loading firearm of FIG. 2.

[0016] FIG. 5 is a bottom sectional view of the firearm bolt assembly for a self-loading firearm of FIG. 2.

[0017] The same reference numerals refer to the same parts throughout the various figures.

DESCRIPTION OF THE CURRENT EMBODIMENT

[0018] An embodiment of the firearm bolt assembly for a self-loading firearm of the present invention is shown and generally designated by the reference numeral 10.

[0019] FIG. 1 illustrates the improved firearm bolt assembly for a self-loading firearm 10 of the present invention. More particularly, the firearm bolt assembly is shown installed in a firearm 100. The firearm has an upper receiver 102, lower receiver 104, barrel 106, suppressor 108, pistol grip 110, trigger 112, magazine 114, and buttstock 116. In the current embodiment, the firearm is an auto-loading rifle.

[0020] FIGS. 2-5 illustrate the improved firearm bolt assembly for a self-loading firearm 10 of the present invention. More particularly, the firearm bolt assembly has a bolt carrier frame 12 having a right side 14, left side 16, front face 18, rear portion 20, top 22, and bottom 24. The frame defines a longitudinal frame axis 26, and the front face defines a central bore 28. The top front of the frame defines a charging handle engagement shelf 30. A cam slot 32 is defined by the top of the frame immediately behind the charging handle engagement shelf. A carrier key attachment area 34 is machined in the top of the frame directly behind the cam slot. A plurality of forward assist notches 36 are machined in the right side of the frame immediately behind the carrier key attachment area. A hammer clearance slot 38, which communicates with the central bore 28 is machined in the top of the frame immediately behind the carrier key attachment area. A flange 40 integral to the frame having a rear face 76 is located immediately behind the hammer clearance slot and forward assist notches. A rear portion 20 extends rearwardly from the rear face of the flange to the rear 78 of the frame. A small turned groove 42 is present adjacent to the rear of the frame.

[0021] A stack of cylindrical, tubular weights 46, 56, 66 separated by resilient spacer elements in the form of elastomeric O-rings 44, 54, 64 is received on the rear portion 20. The front weight 46 has a front 48, rear 50, and central bore 52. The intermediate weight 56 has a front 58, rear 60, and central bore 62. The rear weight 66 has a front 68, rear 70, and central bore 72. The central bores of the weights are sufficiently larger than the outer diameter of the rear portion 20 of the frame 12 to enable the weights to be slidably received on the rear portion. O-ring 44 separates the front of the front weight from the rear face 76 of the flange 40 of the frame. O-ring 54 separates the rear of the front weight from the front of the intermediate weight. O-ring 64 separates the rear of the intermediate weight from the front of the rear weight. A retention fastener 74, which is a spiral ring made of spring steel in the current embodiment, is snapped into the groove 42 to hold the stack of cylindrical weights and O-rings on the rear portion of the frame. The weights are stacked tightly, but the compressibility of the O-rings means the weights are free to slightly reciprocate along the rear portion of the frame. This movement of the weights provide some damping, like a dead-blow hammer, and helps to absorb some energy in the manner of a buffer.

[0022] The weights 46, 56, 66 may be made of different materials having different densities, so that the user or assembler may choose from a range of selected bolt carrier masses determined by the particular weights attached to the bolt carrier frame 12. These metals may include stainless steel and tungsten, as well as other materials including lighter materials such as aluminum or non-metal materials. The bolt carrier frame and weights may be supplied as a kit, with potentially more weights in the kit than can be installed, such as three each of stainless steel and tungsten, with the user or assembler selecting what combination of different metals to use.

[0023] In the preferred embodiment, the mass of a stainless steel weight is 0.58 oz., and the mass of a tungsten weight is 1.36 oz. Therefore, the total mass of the bolt carrier may be varied in steps equal to the difference D between the stainless steel and tungsten weights, with the total range of selectable weights being equal to 3D. The factor of 3 may of course vary based on the number of weights for which length on the rear portion 20 of the frame is provided. The weights may each have the same length, even when being made of different materials.

[0024] The need to change the bolt carrier frame mass (or to provide a custom selected mass) may be based on many factors, including the type of ammunition used, whether or not a suppressor is used, whether firing is fully automatic or semi-automatic, and the type of shooting to be performed. The buffering effect of the rubber O-rings and the ability to tune the mass of the bolt carrier frame so the bolt fully cycles but does not move overly energetically is believed to reduce bolt bounce, especially from fully automatic, suppressed firearm operation, that can cause firearm malfunctions, as well as potentially excessive wear and tear on rifle components.

[0025] 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.

[0026] While a current embodiment of a firearm bolt assembly for a self-loading 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. 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. For example, although a gas impingement mechanism of operation has been disclosed, piston or blowback-operated mechanisms of operation could also be used.

[0027] 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.