Gas key

Abstract

An improved gas key assembly for a fire arm, such as an AR 15 or a M4 rifle, having a gas key fastened by fasteners on a bolt carrier assembly where the gas key moves with the bolt carrier when the fire arm is fired, wherein the gas key has a slot for receiving a key element in the slot and the key element has a stem which is seated in the slot and a rail which overlays the fasteners to removably secure the gas key to the bolt carrier and holds gas key resisting unintended separation of the gas key from the bolt carrier. Also the invention includes a method for securing a gas key to a bolt carrier in such a fire arm.

Claims

1. A bolt carrier assembly for a firearm, said assembly comprising: a bolt carrier barrel arranged for reciprocal movement in said firearm, a gas key adapted to move with said barrel, fastener means attaching said gas key to said barrel, a keyway in said gas key, and a key element in said keyway, said key element overlying said fastener means, said key element adapted to retain said gas key in place during movement of said bolt carrier barrel on said firearm.

2. The bolt carrier assembly recited in claim 1, wherein said gas key is seated on one side of said bolt carrier barrel, and said fastener means is accessible on one side of said gas key remote from said barrel assembly.

3. The bolt carrier assembly recited in claim 2, wherein said gas key has recess means on said side for receiving said fastener means.

4. The bolt carrier assembly recited in claim 3, wherein said fastener means and said gas key have corresponding structure for retaining said fastener in said gas key.

5. The bolt carrier assembly recited in claim 1, wherein said keyway in said gas key has a niche for receiving said key element.

6. The bolt carrier assembly recited in claim 5, wherein said keyway and said key element have corresponding shapes adapted to seat said key element in said gas key niche.

7. The bolt carrier assembly recited in claim 6, wherein said key element and said keyway are trapezoidal in shape.

8. The bolt carrier assembly recited in claim 6, wherein said trapezoidal shape on a side closest to said barrel is wider than on a side remote from said barrel.

9. The bolt carrier assembly recited in claim 1, wherein said key element has a stem adapted for seating in said keyway and rail extending from said stem adapted for seating over said fastener means.

10. A gas key for a fire arm adapted for reciprocal movement responsive to firing said fire arm, said gas key comprising, receiving holes for receiving fasteners, said fasteners attaching said gas key to said fire arm, a keyway in said gas key, said keyway adapted to receive a key element, wherein said key element is adapted to be removably seated in said keyway, said key element is adapted to overlie said fastener means, said key element is adapted to secure said gas key in place on said fire arm, and said key element is selectively removable from said fire arm.

11. The gas key recited in claim 10, wherein said key element comprises a stem adapted for securement in said keyway and a rail extending from said stem adapted to overlay said gas key.

12. The gas key recited in claim 10, wherein said key element stem and said keyway have corresponding shapes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a right side view of the bolt carrier assembly.

(2) FIG. 2 is a perspective view of part of the bolt carrier assembly showing a portion of the gas key secured to the bolt carrier barrel.

(3) FIG. 3 is a perspective view of the key element embodying the present invention.

(4) FIG. 4 is a top view of part of the gas key secured to the bolt carrier barrel, with the key element partially set in the keyway channel and with the rail of the key element partially covering the hex bolt fasteners.

(5) FIG. 5 is an enlarged perspective view of part of the bolt carrier barrel without the key element set into place and showing the keyway channel and the hex bolts.

(6) FIG. 6 is right side view of part of the bolt carrier barrel with the key element set in place in the keyway channel.

(7) FIG. 7 is a right side perspective view of part of the bolt carrier barrel with the key element set into the keyway channel and covering the hex bolt fasteners.

(8) FIG. 8 is a rear perspective view of the gas key partially overlying the bolt carrier barrel showing the key element entering the channel to overlay the hex bolt fasteners.

(9) FIG. 9 is a left side view of the bolt carrier assembly showing the gas key secured to the bolt carrier barrel and the key element set in the keyway channel on the gas key.

(10) FIG. 10 is a top view of the bolt carrier assembly with the gas key secured to the bolt carrier barrel.

(11) FIG. 11 is a bottom plan view of the bolt carrier assembly.

(12) FIG. 12 is a front elevation view of the bolt carrier Assembly with the gas key mounted thereon.

(13) FIG. 13 is a rear elevation view of the bolt carrier assembly with the gas key mounted thereon.

(14) FIG. 14 is a top perspective view of a typical unmounted gas key.

DETAILED DESCRIPTION OF THE DRAWINGS

(15) In a bolt carrier assembly 5, the gas key 20 is fastened using two hex bolts 30 to the bolt carrier barrel 10. The gas key 20 has a fore hex bolt receiving hole 40 and an aft hex bolt receiving hole 50. Each hex bolt receiving hole 40 and 50, respectively, is of a diameter and depth so that the head of the fore hex bolt 70 and the head of the aft hex bolt 80 is completely recessed into each hex bolt receiving hole 40 and 50, respectively. The gas key 20 is bolted to the top of the bolt carrier barrel 10 using two hex bolt fasteners 30. The gas key 20 is fabricated with a keyway channel 60 cut across it in the area between the fore hex bolt receiving hole 40 and the aft hex bolt receiving hole 50. The walls of the keyway channel 60 preferably taper outwardly from the top of the gas key 20 and have a trapezoidal cross-section. In the preferred embodiment, the keyway channel 60 is wide enough at its base so that the keyway channel 60 may cut into the fore hex bolt receiving hole 40 and the aft hex bolt receiving hole 50. In alternate embodiments, the keyway channel 60 need not cut into either hex bolt receiving hole and may have a cross-section other than trapezoidal so long as the key element is well secured in the gas key, even against substantial forces resulting from the fire arm firing action. In yet another alternate embodiment, the keyway channel 60 may cut into only one of the hex bolt receiving holes.

(16) To prevent separation or lifting of the gas key 20 from the bolt carrier barrel 10 due to loosening of the hex bolt fasteners 30, the key element 90 is set snuggly into the keyway channel 60. The key element 90 may be preferably somewhat T shaped and may comprise of a stem 100 and a rail 110. The stem 100 may have a stem fore edge 120 and a stem aft edge 130. The rail 110 may comprise a rail top 140 and a rail bottom 150. In the preferred embodiment, the stem 100 of the key element 90 is preferably trapezoidal in shape so that pressure exerted to the rail bottom 150 by one or both of the fasteners 30 causes the stem fore edge 120 and stem aft edge 130 to exert pressure on the keyway channel 60 to keep the hex bolt fasteners 30 from backing out of the fastener receiving holes 40 and 50, thus preventing the gas key 20 from separating from the bolt carrier barrel 10.

(17) While the invention has been described and shown in substantial detail, many modifications and changes can be made in the structure disclosed without departing from the scope and spirit of the invention. The invention should not be limited of the exact structure disclosed.