U.S. patent application number 14/190919 was filed with the patent office on 2015-08-27 for adjustable gas key for autoloading firearm.
This patent application is currently assigned to RUBBER CITY ARMORY. The applicant listed for this patent is RUBBER CITY ARMORY. Invention is credited to ROBERT SHADE MCMILLEN, IV.
Application Number | 20150241149 14/190919 |
Document ID | / |
Family ID | 53881868 |
Filed Date | 2015-08-27 |
United States Patent
Application |
20150241149 |
Kind Code |
A1 |
MCMILLEN, IV; ROBERT SHADE |
August 27, 2015 |
ADJUSTABLE GAS KEY FOR AUTOLOADING FIREARM
Abstract
Aspects herein relate to a system for controlling the flow of
gas to a moving parts assembly in an autoloading firearm cycled at
least in part using gas produced from firing of the autoloading
firearm. The system can include means for establishing fluid
communication with a gas source providing the gas during at least
one portion of the firearm firing cycle, a conduit of the means for
establishing fluid communication including an inlet corresponding
to the gas source and an outlet directing at least a portion of the
gas toward the moving parts assembly, and a means for modifying the
flow of gas through the conduit. Also provided are methods for
making and using adjustable gas keys.
Inventors: |
MCMILLEN, IV; ROBERT SHADE;
(CUYAHOGA FALLS, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RUBBER CITY ARMORY |
Akron |
OH |
US |
|
|
Assignee: |
RUBBER CITY ARMORY
Akron
OH
|
Family ID: |
53881868 |
Appl. No.: |
14/190919 |
Filed: |
February 26, 2014 |
Current U.S.
Class: |
89/193 |
Current CPC
Class: |
F41A 5/28 20130101 |
International
Class: |
F41A 5/28 20060101
F41A005/28 |
Claims
1. A system for controlling gas flow to a moving parts assembly in
an autoloading firearm cycled at least in part using gas produced
from firing of the autoloading firearm, comprising: means for
establishing fluid communication with a gas source providing the
gas during at least one portion of a firing cycle of the
autoloading firearm; a conduit of the means for establishing fluid
communication including an inlet corresponding to the gas source
and an outlet directing at least a portion of the gas toward the
moving parts assembly; and a means for modifying the gas flow
through the conduit.
2. The system of claim 1, wherein the means for establishing fluid
communication is an upper interface of an adjustable gas key.
3. The system of claim 2, further comprising an attachment means
that operatively couples the adjustable gas key with the moving
parts assembly.
4. The system of claim 2, wherein the means for modifying the gas
flow is an adjustment aperture in fluid communication with the
conduit incident to at least a portion of the conduit.
5. The system of claim 4, wherein the adjustment aperture is
incident to the conduit from the rear of the adjustable gas
key.
6. The system of claim 4, wherein the adjustment aperture receives
an adjustment control.
7. The system of claim 6, wherein the adjustment aperture is
threaded, and wherein the adjustment control is a screw.
8. The system of claim 6, further comprising an internal recess
that receives at least a portion of the adjustment control.
9. The system of claim 1, wherein the moving parts assembly is a
lightweight moving parts assembly.
10. A method of making an adjustable gas key for an autoloading
firearm, comprising: providing a gas key having an angled portion
and an upper interface, the angled portion directs at least a
portion of gas from firing the autoloading firearm toward a moving
parts assembly, the upper interface maintains fluid communication
with a gas source during at least a portion of a firing cycle of
the autoloading firearm, wherein a continuous conduit is provided
through the upper interface and angled portion; and forming an
adjustment aperture in fluid communication with the conduit
incident to at least a portion of the conduit.
11. The method of claim 10, further comprising arranging an
adjustment control in the adjustment aperture.
12. The method of claim 11, further comprising forming an internal
recess in a portion of the conduit distinct from the portion of the
conduit incident to the adjustment aperture.
13. The method of claim 10, further comprising threading the
adjustment aperture.
14. The method of claim 11, further comprising providing a screw in
the adjustment aperture.
15. The method of claim 10, wherein the gas key is a gas key of an
M-16 type rifle.
16. A method of adjusting a firing characteristic of an autoloading
firearm cycled at least in part using gas produced from firing of
the autoloading firearm, comprising modifying a flow of gas
resultant to firing of the autoloading firearm within a gas
key.
17. The method of claim 16, wherein modifying the flow of gas is
accomplished at least in part by restricting the flow of gas
through the gas key.
18. The method of claim 17, wherein restricting the flow of gas
through the gas key is accomplished at least in part by seating a
screw to at least partially interrupt a conduit of the gas key.
19. The method of claim 18, further comprising turning the screw to
open or close the conduit of the gas key.
20. The method of claim 17, wherein modifying the flow of gas is
accomplished at least in part by venting at least a portion of the
gas from the gas key in a direction alternative to that of a moving
parts assembly of the autoloading firearm.
Description
TECHNICAL FIELD
[0001] The disclosures herein relate in general to firearms. More
particularly, aspects herein relate to autoloading firearms which
are operated at least in part by gases from firing.
BACKGROUND
[0002] Since the invention of firearms, shooters have sought to
increase the efficiency of the firing process. One aspect of such
efficiency is the speed between shots, which is partially a
function of any reloading that must occur before subsequent firing,
as well as the time required to bring the direction of fire back to
the target based on changes from a previous shot.
[0003] Multi-barreled firearms were an early solution to expedite
the speed with which a subsequent shot could be fired. The
following centuries brought revolvers containing multi-shot
cylinders and manually-cycled repeating arms such as lever- and
pump-action weapons having tubular magazines. Internal box
magazines were employed with multi-shot bolt rifles. Later, firearm
designers successfully harnessed the forces of firing, permitting
the firearm to cycle its action automatically with each trigger
pull, thus introducing autoloading firearms. The development of
clips, belted ammunition, and detachable magazines cemented the
superiority of the autoloading firearm in the decades that
followed.
[0004] As shooters can now fire several cartridges without
conducting manual reloading actions, the limiting factor in
subsequent shots is frequently a shooter's ability to properly aim
the weapon at the target. Recoil (and other forces from firearm
operation) frequently cause the muzzle direction to change after
firing. Other factors (such as averseness to muzzle blast) can
further influence a shooter's ability to maintain the sights on the
target. Accordingly, shooters frequently seek modifications or
enhancements to aid in control of the firearm during shooting.
[0005] Further, some modifications or accessories (such as
suppressors) change the forces at work on the firearm during
firing. It is therefore at times desirable to change aspects of the
firearm's function (e.g., modify the flow of gas) to better
accommodate such modifications or accessories.
SUMMARY
[0006] Aspects herein include a system for controlling the flow of
gas to a moving parts assembly in an autoloading firearm cycled at
least in part using gas produced from firing of the autoloading
firearm. The system can include means for establishing fluid
communication with a gas source providing the gas during at least
one portion of the firearm firing cycle, a conduit of the means for
establishing fluid communication including an inlet corresponding
to the gas source and an outlet directing at least a portion of the
gas toward the moving parts assembly, and a means for modifying the
flow of gas through the conduit.
[0007] Embodiments of a method for making an adjustable gas key
include providing a gas key having an attachment portion, an angled
portion, and an upper interface, the attachment portion operatively
couples the gas key to a moving parts assembly of an autoloading
firearm cycled at least in part using gas produced from firing of
the autoloading firearm, the angled portion directs at least a
portion of gas from firing the autoloading firearm toward the
moving parts assembly, the upper interface maintains fluid
communication with a gas source during at least a portion of the
autoloading firearm firing cycle, and forming an adjustment
aperture in fluid communication with the conduit incident to at
least a portion of the conduit.
[0008] With gas keys as disclosed herein, there can be embodiments
of a method of adjusting a firing characteristic of an autoloading
firearm cycled at least in part using gas produced from firing of
the autoloading firearm, comprising modifying a flow of gas
resultant to firing of the autoloading firearm within a gas
key.
[0009] Various aspects will become apparent to those skilled in the
art from the following detailed description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A illustrates a system including a bolt carrier group
for an autoloading firearm.
[0011] FIG. 1B illustrates an exploded view of the bolt carrier
group of FIG. 1A.
[0012] FIG. 2 illustrates a cutaway view of the bolt carrier group
of FIG. 1A.
[0013] FIG. 3A illustrates a solid view of a gas key of the bolt
carrier group of FIG. 1A.
[0014] FIG. 3B illustrates a cross-sectional view of a gas key of
the bolt carrier group of FIG. 1A.
[0015] FIG. 4 illustrates a solid view of an embodiment of an
adjustable gas key disclosed herein.
[0016] FIG. 5 illustrates a cross-sectional view of an embodiment
of an adjustable gas key disclosed herein.
[0017] FIG. 6 illustrates a cross-sectional view of an embodiment
of an adjustable gas key disclosed herein.
[0018] FIG. 7 illustrates a cross-sectional view of an embodiment
of an adjustable gas key disclosed herein.
[0019] FIG. 8 illustrates an embodiment of a methodology for
producing an adjustable gas key disclosed herein.
[0020] FIG. 9 illustrates an embodiment of a methodology for
modifying a firing characteristic of an autoloading firearm using
an adjustable gas key disclosed herein.
[0021] FIG. 10 illustrates an embodiment of a methodology for
calibrating a firing characteristic of an autoloading firearm using
an adjustable gas key disclosed herein.
DETAILED DESCRIPTION
[0022] The disclosures herein generally relate to an adjustable gas
key for an autoloading firearm. The adjustable gas key can
selectively restrict the flow of gas through the gas key to a
moving parts assembly, thereby modifying firing characteristics of
the weapon.
[0023] As used herein, an autoloading firearm can include any
firearm which will chamber another cartridge after firing without
manual action from a firearm operator (e.g., semiautomatic,
automatic) provided ammunition is available (via, e.g., a magazine,
belt). While the distinction is readily appreciated with reference
to bolt- or lever-action firearms, such also distinguishes from,
for example, a double-action revolver to the extent that pulling of
the trigger performs the mechanical action of cycling the cylinder.
The cycle of autoloading firearms (e.g., "firearm firing cycle") is
discussed in greater detail below.
[0024] The M-16 service rifle is generally referred to herein as
the example system on which an adjustable gas key is utilized.
Those of ordinary skill in the art will appreciate the variants of
this system, and the applicability of such disclosures to the same.
For example, the M-4 carbine and countless variants of the AR-15
rifle are other platforms chambered in the 5.56.times.45 mm NATO
(or similar .223 Remington) cartridge which use identical or
near-identical parts to those of the M-16. Further, firearms such
as the AR-10 (chambered in 7.62.times.51 mm NATO or similar .308
Winchester) and variants thereof use parts of similar design. While
these calibers comprise a large proportion of firearms of this
design, various complete firearms or modular kits are available to
chamber rifles of this style in a wide variety of other calibers
(e.g., .22 long rifle, 9 mm parabellum, 7.62.times.39, .300
Blackout, 6.8 mm Remington SPC, 5.45.times.39 mm, 6.5 Grendel, .458
SOCOM, .450 Bushmaster, .300 Whisper, .338 Whisper, .204 Ruger, .50
Beowulf). A large number of manufacturers produce components for
such firearms or entire firearms of such patterns, including Rubber
City Armory, Lewis Machine and Tool, JP Enterprises, Colt Defense,
Armalite, Rock River Arms, Bravo Company Manufacturing, Bushmaster,
CMMG, Daniel Defense, DPMS, FN Herstal, Heckler and Koch, Knight's
Armament Company, Lame Tactical, Magpul, LWRC International,
Mossberg, Noveske, Patriot Ordinance Factory, Remington, Sturm
Ruger and Company, Sig Sauer, Stag Arms, Wilson Combat, Yankee Hill
Manufacturing, and many others.
[0025] While the examples provided above generally belong to a
single family or class of firearms (the M-16 type), and their
differences are generally directed toward accommodating or
retrofitting for particular sizes of cartridges and the forces
associated with their firing, various other firearms having
similarities in their moving parts assemblies can also be modified
according to components and techniques herein. For example, the
internal piston design M-16 type rifle is frequently compared to or
conflated with direct impingement gas systems, for which
disclosures herein may be adapted. In another example, variants of
M-16 style rifles modify the moving parts to effect a blowback
system for autoloading (e.g., kits modifying such firearms to
accommodate 9 mm parabellum rounds). In this regard, aspects herein
can be utilized with firearms operating using direct impingement
gas systems, external pistons, blowback designs, alternative
internal piston designs, or other mechanisms for effecting
automatic loading without departing from the scope or spirit of the
innovation, and nothing herein should be interpreted as limiting
application of techniques herein exclusively to gas systems such as
those illustrated.
[0026] M-16 type firearms and other autoloading firearms are
typically designed to provide more than enough forces to moving
parts than is required to properly cycle the firearm. For example,
in M-16 type firearms, the gases force a bolt carrier group
violently against a buffer and spring which compresses into a
buffer tube. Residual force is absorbed by the buffer tube and/or
stock (and ultimately the shooter) when the buffer and contacting
bolt carrier group fully compress the spring against the end of the
buffer tube. By providing excess force, the reliability of M-16
type firearms is increased, as it is more likely that the bolt
carrier group will move a distance adequate to eject the spent
casing and seat the bolt behind a new cartridge in the magazine.
However, it is possible to reduce the force with which the bolt
carrier group is propelled toward the buffer without compromising
the ability of an M-16 type firearm to complete its cycle of
operations.
[0027] As used herein, a "gas key" or "carrier key" is a mechanical
part operably coupling two or more parts of a firearm gas system.
For example, in the context of the M-16 style rifles, the gas key
is a shaped form attached to a bolt carrier. The gas key mates with
a gas tube in a receiver and redirects gases traveling from the gas
tube downward into the bolt carrier. Those of ordinary skill in the
art will appreciate gas keys in other firearm systems, which can be
identified by the same or alternative nomenclature, which can be
produced or modified in accordance with aspects herein.
[0028] As used herein, a "moving parts assembly" includes
mechanical components (typically, but not necessarily, provided in
the receiver or upper receiver of an autoloading firearm) which
displace during the firing cycle (described in greater detail
below) of the autoloading firearm to directly or indirectly
accomplish various stages of the firing cycle (e.g., ejecting,
cocking, chambering).
[0029] As used herein, an "adjustment aperture" indicates an
aperture formed in a component deviating from a military or
commercial specification for the component. For example, current
carrier key specifications instruct production of a gas conduit
with one inlet and one outlet. An adjustment aperture can be any
additional aperture supplemental to the two means of reaching the
space enclosed by the gas key necessary for function of the
associated firearm. As used herein, an "adjustment control" is a
mechanism for opening an adjustment aperture, closing an adjustment
aperture, or selectively interrupting a path of fluid communication
at least in part using an element provided through the adjustment
aperture.
[0030] Modifications described herein are performed at least in
part to augment at least one firing characteristic of an
autoloading firearm. In this regard, firing characteristics can
include felt or absolute recoil, perceived or absolute muzzle blast
or flash, muzzle climb, torque or imbalance from firing, cyclic
rate or aspects thereof (e.g., velocity of moving parts), pressure
concentration or dissipation in components during firing, et
cetera. More generally, firing characteristics can include any
consequence to firing in terms of impact on the shooter, the
cartridge, or the weapon.
[0031] Directional terms (e.g., rearward, forward, side, top,
bottom, and others) in this application are generally intended to
refer to directions in reference to a firearm held upright in a
standard firing position. "Forward," "front," and similar
terminology will refer toward the direction of bullet travel, or
the muzzle-end of the firearm. "Rearward," "back," and similar
terminology refers to the direction opposite bullet travel, or the
stock-end of the firearm in firearms having a stock. The top of the
firearm is the portion on which sights and/or carry handles are
typically installed, and typically the highest-held portion when
the weapon is in an upright firing position. The bottom of the
firearm is the direction in which the trigger or pistol grip
protrude from the receiver (e.g., a lower receiver).
[0032] "Operatively coupling" used herein describes components
which act upon one another. Such action can be accomplished through
mechanical interaction of solid components which are directly
connected or which exert forces on one another through various
linkages or at a distance. Such action can also be accomplished
through fluid communication, which can be effected directly or
through the direction of fluid matter through intervening or
connecting components. Components or voids which are "incident" are
those that intersect or couple. For example, an aperture is
incident to a conduit when it passes through the wall of a conduit
to establish at least partial connectivity between the two.
[0033] Turning to the drawings, FIGS. 1A, 1B, 2, 3A, and 3B
generally show aspects of the prior art related to the gas system
of an autoloading firearm. The gas system uses gases propelling the
bullet down the barrel to cycle the action of the firearm by
tapping the barrel such that some of the expanding gas returns to
the receiver in a direction opposite the bullet's line of travel
down the barrel.
[0034] Autoloading firearms can be described in terms of their
firing cycle, or the various stages performed each time the weapon
is fired and resets itself for subsequent firing automatically. In
the example of an M-16 type rifle, the firearm has several steps in
its firing cycle: firing, unlocking, extracting, ejecting, cocking,
feeding, chambering, and locking. The rifle fires when a hammer
strikes firing pin 158, which strikes a primer of a cartridge. The
primer ignites the propellant in the casing, which rapidly expands.
The expanding propellant separates the bullet from the casing and
forces the bullet down the barrel. A gas block is attached to the
barrel above a gas tap and includes a port into which gas tube 190
is disposed. The gas block includes a channel through which gas can
pass into the gas block and to the gas tube from the gas tap.
Therefore, no later than when the bullet passes the gas block of
the barrel, some of the gases conveying the bullet exit the barrel
via the gas tap interfacing with the gas block. These gases are
then rerouted down gas tube 190 parallel to the barrel and re-enter
the rifle's receiver. Gas tube 190 mates with upper interface 130
of gas key 102 (which may alternatively be called a carrier
key).
[0035] After entering gas key 102, the gas travels through upper
interface 130 and is turned into angled portion 120. Angled portion
120 includes carrier interface opening 122 which routes the gases
from firing into carrier 150. This effects the second step of the
cycle, unlocking, whereby the gases in carrier cylinder 168 of
carrier 150 press bolt 170 forward and carrier 150 rearward.
Specifically, pressure on gas rings 175 ensures bolt 170 remains
seated in the chamber and prevents wear on locking lugs 171 while
carrier 150 moves rearward. The rearward motion of carrier 150
causes translation of cam 166 in cam track 164. Cam 166 is seated
in cam hole 179 of bolt 170 such that bolt 170 is rotated through
the motion of cam 166. The rotation of bolt 170 causes locking lugs
171 to unlock, realigning to pass through the corresponding lugs of
the chamber.
[0036] Once unlocking is completed, bolt 70 can travel rearward
with the carrier 150 and exit the chamber. Extractor 172 exerts
force on the rim of a cartridge while bolt 170 leaves the chamber
and extracts the cartridge casing from the chamber. After
extracting is complete, the cartridge casing is ejected from the
receiver. Carrier 150 includes an angled face under firing pin 158,
which forces the hammer down as carrier 150 moves rearward. The
hammer is pushed down sufficiently to reengage the sear and is held
in place until the next cycle of operation. This completes the
cocking stage of the firing cycle.
[0037] The rearward motion of carrier 150 is controlled using a
buffer and buffer spring. Once carrier 150 ceases rearward motion
(i.e., by compressing a spring in a buffer tube), the spring causes
carrier 150 to travel forward toward the chamber again. A cartridge
from the magazine is permitted to advance upward under force from a
spring-loaded magazine follower when bolt 170 moves rearward past
the end of the cartridge, and stripped out of the magazine by the
return of bolt 170 during the feeding stage of the firing cycle.
The chambering step follows, whereby the stripped round is forced
into the chamber of the rifle. The forward motion of carrier 150
behind the bolt now pressed into the chamber causes cam 166 to
travel cam track 164, rotating locking lugs 171 into alignment with
the chamber lugs, effecting locking of bolt. This completes the
firing cycle, and the autoloading rifle is prepared to repeat the
cycle for the next shot.
[0038] FIG. 1A specifically shows a system 100 including a bolt
carrier group having carrier 150, bolt 170, and gas key 102. The
bolt carrier group is shown in reference to charging handle 180,
which gas key 102 nests in when assembled, and gas tube 190.
Charging handle 180 is used for manual manipulation of the bolt
carrier group, but does not reciprocate with the bolt carrier group
during firing. Charging handle 180 can include a hole to permit one
or both of gas key 102 and/or gas tube 190 to pass through a
portion of one or more of its faces. The underside of charging
handle 180 can be configured to overlay at least a portion of gas
key 102, and the upper and/or outer surfaces can be sized and
shaped to mate with a channel of a firearm receiver (e.g., upper
receiver). Gas tube 190 is oriented parallel to a barrel and
connects opposite the end shown to a gas block secured over a tap
in the barrel which establishes fluid communication between the
barrel and receiver by a route different from the barrel
itself.
[0039] Carrier 150 operably couples the components of the bolt
carrier group. When the bolt carrier group is assembled, carrier
150 houses bolt 170, which functions as an internal piston during
the firing cycle described above. Gas key 102 is connected to
carrier 150 using fasteners such as screws, which can be reinforced
using various thread-locking substances, staking of the screw heads
and/or attachment portion 110, or other means.
[0040] FIG. 1B shows an exploded view of the bolt carrier group of
system 100. Visible in greater detail, gas key 102 includes
attachment portion 110, angled portion 120, and upper interface
130. Upper interface 130 defines at least an opening of conduit
132, the space through which gas is routed from the gas tube, which
is redirected through angled portion 120 down toward the carrier
150. Attachment portion 110 extends from angled portion 120, and
facilitates attachment of gas key 102 to carrier 150. Attachment
can be effected using, for example, one or more fasteners 114 which
can extend through key fastener holes 112 into carrier fastener
holes 156.
[0041] Carrier 150 includes a carrier cylinder 168 (better visible
in FIG. 2) into which the gases from gas key 102 are projected by
passing through carrier gas entrance 152. Carrier gas entrance 152
aligns with carrier interface opening 122 (better visible in FIG.
3B). Firing pin 158 is housed in carrier 150. Carrier 150 is formed
such that the hammer swings through openings behind the firing pin
to contact the firing pin without hitting carrier 150 (at least
until after the pin is struck in each firing cycle). Firing pin 158
is held in carrier 150 using firing pin retaining pin 160, which
nests in retaining pin hole 162. Carrier 150 can include one or
more vent holes 154 to prevent overpressure in carrier 150 from
gases vented into such, as well as effect collateral functions such
as blowing open a dust cover which can be closed to isolate the
opening of the receiver through which fired cartridge casings are
ejected when no the weapon is not being fired. Additional gases may
escape through other portions of carrier 150 (e.g., passage in
which firing pin 158 is held, cam track 164) which are not fluidly
sealed.
[0042] Carrier 150 includes cam track 164 in which cam 166 is
inserted. When the bolt carrier group is assembled, bolt 170 is
housed in carrier 150 through bolt opening 169, and cam 166 is also
passed through cam hole 179 of bolt 170. When cam 166 is removed,
bolt 170 spins freely in carrier 150, and can be removed entirely
from carrier 150. With cam 166 installed, the motion of bolt 170 is
defined by cam track 164, which limits translation and motion to a
specific path matching the geometries of the chamber and receiver
during firing.
[0043] Bolt 170 includes gas rings 175 which facilitate sealing of
the bolt in bolt opening 169 of carrier cylinder 168 and enable the
piston action of bolt 170. Bolt 170 also includes extractor 172,
which is retained by extractor pin 173 and acted upon by extractor
spring 174. In embodiments, extractor spring 174 can be
supplemented with an o-ring or other compressible member to ensure
the desired amount of resistance is applied by extractor 172 to the
rim of a cartridge. Bolt 170 further includes ejector 176, coupled
with ejector spring 177. Both ejector 176 and ejector spring 177
are retained by ejector pin 178.
[0044] FIG. 2 shows a cutaway view of the bolt carrier group of
system 100. Carrier cylinder 168 in which bolt 170 moves can be
better appreciated, as can the positioning of vent holes 154 in
relation to the moving parts of the bolt carrier group.
[0045] FIGS. 3A and 3B show gas key 102 in isolation permitting
appreciation for its details. While not each aspect of gas key 102
(or other components here) is expressly discussed, the major
portions of gas key 102 are described as upper interface 130,
angled portion 120, and attachment portion 110. Gas is received in
upper interface 130, passing into conduit 132. Conduit 132 defines
a path which redirects the gas at an angle through angled portion
120 toward carrier interface opening 122. Attachment portion 110
can include key fastener holes 112 to attach gas key 102 to a
moving part of the gas system (e.g., carrier 150). Attachment
portion 110 can have a wider dimension or cross section than at
least upper interface 130, and can include various cutaway
portions, recesses, flanges, bosses, et cetera. FIG. 3B in
particular also shows gas tube 190 mated with upper interface
130.
[0046] With the general functioning of an example autoloading gas
system now understood, FIGS. 4-7 show example embodiments of an
adjustable gas key in accordance with the disclosures herein. FIG.
4 in particular shows one embodiment of an adjustable gas key 400
having attachment portion 410, angled portion 420, and upper
interface 430. Upper interface 430 has an inlet wherein gas enters
gas key 400 from a gas source (e.g., a gas tube). Angled portion
420 at least in part defines an outlet where gas can exit gas key
400 (e.g., into a bolt carrier group). Gas key 400 can be attached
to moving parts of a firearm gas system using fasteners 414.
Notably, gas key 400 includes adjustment screw 428 which can be
moved screwed in or out of angled portion 420 and/or upper
interface 430 to restrict the flow of gas through gas key 400.
Additional details to this effect will be understood through
discussion of FIGS. 5-7.
[0047] Various components described herein can be "lightweight"
components. A lightweight component is one that has had material
removed and/or is formed at least in part from materials differing
from a standard specification part (e.g., military specification
bolt carrier group) to reduce the mass of the component(s).
Adjustable gas key 400 (and other adjustable gas keys herein) can
be operatively coupled with a lightweight bolt carrier group or
lightweight moving parts assembly via attachment portion 410.
Because adjustable gas key 400 (and other adjustable gas keys
herein) may reduce the amount of gas entering a moving parts
assembly, lightweight components (and other complementary
modifications such as reduced-coefficient springs or lightweight
buffers) may be employed to ensure reliable cycling under reduced
force from gas. Further, the use of lightweight components can
further modify firing characteristics according to operator
preferences.
[0048] While attachment portion 410 (and other attachment portions
herein) are shown as accepting fasteners, it is understood that
alternative mechanisms for providing a gas key to a moving parts
assembly are embraced by the disclosures herein. For example, gas
keys can be formed integrally on one or more parts of a moving
parts assembly, such that attachment portion is a subcomponent of a
larger continuous piece of material. In specific embodiments of
such examples, not attachment portion may be discernible from other
sections. Alternatively, attachment portion 410 could be welded,
attached with adhesives, or operatively coupled with a moving parts
assembly means other than those illustrated in FIG. 4 (or other
figures).
[0049] FIG. 5 shows a cutaway view of an embodiment of a modified
gas key 500 having an adjustment aperture 526 formed in angled
portion 520 of gas key 500. In gas key 500, adjustment aperture 526
is formed through the rear-facing wall of angled portion 520.
Adjustment aperture 526 may be left open to permit venting of gas
passing through conduit 532 to the rear of gas key 500 during
operation. In various embodiments, adjustment aperture 526 may be
partially or wholly obstructed to change the amount of gases vented
through adjustment aperture 526.
[0050] In alternative or complementary embodiments, an adjustment
control can be provided at least partially through adjustment
aperture 526 to modify the flow of gas through carrier interface
opening 522 via conduit 532 (e.g., by redirecting or obstructing
the passages through which gas can flow). However, the disclosures
herein do not require that an adjustment control be provided
through any one or more adjustment apertures in each and every
embodiment. In alternative or complementary embodiments, other
adjustment apertures can be provided in addition to adjustment
aperture 526. While adjustment aperture 526 is shown formed in a
specific location of gas key 500, it is understood that alternative
positioning and orientation is embraced under the disclosures
herein.
[0051] Attachment portion 510 is similar to other attachment
portions herein, and includes gas key fastener holes 512. Likewise,
upper interface 530 is similar to other upper interface portions
herein.
[0052] FIG. 6 shows a cutaway view of an embodiment of a modified
gas key 600 having an adjustment aperture 626 in combination with
adjustment control 628. Adjustment control 628 can be variably
inserted or removed through adjustment aperture 626 to open or
close at least a portion of conduit 632. By changing the proportion
of conduit 632 which is blocked by adjustment control 628, the
amount of gas passing through carrier interface opening 622 to a
moving parts assembly of an autoloading firearm. This in turn
modifies firing characteristics of the firearm (e.g., by changing
the distribution of forces throughout components during the firing
cycle). The firing characteristics of the firearm can be modified
in a binary fashion (e.g., gas permitted through or blocked) or
through a continuous scale of quantity or quality (e.g., different
amounts of gas blocked) through use of adjustment aperture 626
and/or adjustment control 628.
[0053] Adjustment control 628 can be hollow and/or include ports to
permit gases to vent through adjustment control 628 (e.g., hollow
screw). Adjustment control 628 may, in some embodiments be
impermeable and block air entirely in spaces it occupies.
Alternatively, adjustment control 628 may be partially permeable
(e.g., constructed in part of a permeable material or perforated)
and restrict only a portion of gases coming into contact with
adjustment control 628.
[0054] Adjustment control 628 can be a screw matched to threading
in adjustment aperture 626, the turning of which can open or close
at least a portion of conduit 632. The screw can have various heads
or other tool interfaces, or can include a portion which extends
for hand-manipulation. Portions of the screw for its manipulation
can be textured, knurled, magnetized, et cetera, to facilitate ease
of turning, insertion, or removal.
[0055] In various embodiments, sizing of adjustment control 628 can
be based on a dimension of angled portion 620, conduit 632, and/or
other portions. For example, in an M-16 type autoloading firearm
chambered in 5.56.times.45 mm NATO, gas key 600 is a standard gas
key approximately 0.245 inches wide at angled portion 620.
Therefore, embodiments of the adjustment control 628 are less than
0.245 inches, because any adjustment control widening the profile
of angled portion 620 would fail to fit in the corresponding
channel of the charging handle in which gas key 600 is disposed
during operation. It is understood that, while dimensions may
differ, the same principles apply in other chambering (e.g., AR-10
chambered in 7.62.times.51 mm NATO) of M-16 type rifles as well as
in other types of firearms utilizing similar carrier keys.
[0056] In embodiments where adjustment control 628 is a screw and
the autoloading firearm in which gas key 600 is integrated is an
M-16 type rifle chambered in 5.56.times.45 mm NATO, examples of
screw sizes that can be used include 1/16'', 3/32'', 1/8'', 5/32'',
3/16'', 7/32'', and other sizes smaller than the 0.245'' maximum
dimension. Various alternatives (including metric sizes) can also
be employed. Further, a system into which gas key 600 is integrated
can be provided with two or more screws to facilitate additional
adjustments based on screw design (e.g., length, tip profile,
hollow/ported or solid, perforated or continuous).
[0057] Adjustment control 628 can alternatively be a button, snap,
sliding member, or various others mechanical components which can
be connected, disconnected, or moved through adjustment aperture
626 such that the flow of gas through conduit 632 is modified and
adjustment control 628 withstands the forces of operation in the
autoloading firearm.
[0058] Various embodiments can include coarser or finer adjustment
means through use of adjustment aperture 626 and adjustment control
628. For example, in embodiments where adjustment aperture 626 and
adjustment control 628 are threaded, finer or coarser threading,
pitch, lead, or other thread variables can be modified to increase
or decrease the number of turns required to displace adjustment
control 628 by a specified distance, accordingly permitting finer
adjustment of modifications to firing characteristics.
[0059] Adjustment control 628 can be configured to permit measuring
or observation of adjustments, or display discrete adjustment
amounts during use. For example, in embodiments where adjustment
control 628 is a screw (or another mechanical component which is
turned to modify its position at least with respect to conduit
632), one or both of adjustment control 628 and angled portion 620
can include markings indicating various angles or displacements.
This assists an operator at least by providing knowledge of the
absolute or relative position of an adjustment control 628 without
requiring observation of firing characteristics.
[0060] In alternative or complementary embodiments, adjustment
control 628 and/or adjustment aperture 626 can be toothed, notched,
and/or coupled with detents or springs to facilitate detectable
"clicks" associated with an amount of angular displacement or known
position. For example, clicks can be set such that each tenth of a
rotation is detected. Alternatively, clicks can be set at an open
position, closed position, and/or arbitrary position therebetween.
In this way, an operator can precisely and repeatably position
adjustment control 628 for known and rapid modification of firing
characteristics. In addition to providing known, measurable changes
to adjustment control 628, such aspects can also retain the
position of adjustment control 628 such that the setting of
adjustment control 628 will not slip or be lost during firing or
other manipulation.
[0061] Attachment portion 610 is similar to other attachment
portions herein, and includes gas key fastener holes 612. Likewise,
upper interface 630 is similar to other upper interface portions
herein.
[0062] FIG. 7 illustrates an embodiment of a modified gas key 700,
where in addition to adjustment aperture 726 and adjustment control
728, gas key 700 includes internal recess 729. Internal recess 729
may be an extension of adjustment aperture 726 into a portion of
conduit 732 opposite the area of incidence between adjustment
aperture 726 and conduit 732. Alternatively, internal recess 729
may be distinct from adjustment aperture 726 (e.g., in location,
dimensions, profile). In some embodiments, internal recess 729
provides a space with which adjustment aperture 726 can mate. Such
mating can be for purposes of strength or stability, to permit
adjustment control 728 to be flush with or recessed below a surface
of angled portion 720, to fully seal conduit 732, et cetera.
[0063] Alternatively, recess 729 can provide a curve path for gas
to follow around adjustment control 728 partially obstructing
conduit 732. By modifying the path, the distances, pressures, and
velocities of operation may be varied to modify firing
characteristics.
[0064] In some embodiments, conduit 732 can have a cross-section
(cutting gas key 700 along a right-to-left line, from top to bottom
and perpendicular to a line from front to rear) having at least one
flat side or portion. Put another way, conduit 732 can be
non-cylindrical or non-rounded, and can be formed to any arbitrary
cross section provided the outer dimensions accord with the
dimensions required for use in the autoloading firearm. In this
way, tighter closing can be accomplished. For example, where
conduit 732 has straight walls, adjustment control 728 of constant
cross-section can fully close conduit 732 or portions thereof it
interrupts. Alternatively, adjustment aperture 726 can be larger
than conduit 732 in at least one dimension to permit full sealing
through rounded side(s) with an adjustment control 728 larger than
the widest dimension between the rounded side(s).
[0065] Attachment portion 710 is similar to other attachment
portions herein, and includes gas key fastener holes 712. Likewise,
upper interface 730 is similar to other upper interface portions
herein. Attachment portion 710 ensures proper alignment between
carrier interface opening 722 and a moving parts assembly to which
modified gas key 700 is attached.
[0066] As noted, FIGS. 5-7 illustrate single adjustment apertures
oriented through the rear-facing wall of angled portions of the
respective gas key embodiments. However, one of ordinary skill in
the art will appreciate that adjustment apertures and associated
adjustment controls can be arranged at other locations on
respective gas keys in alternative or complementary embodiments.
While forming of the adjustment aperture in the illustrated
location prevents the adjustment aperture and/or adjustment control
avoids interference with contacting components (e.g., charging
handle or gas tube) and permits easy access to the adjustment
aperture (e.g., while the gas key is attached to a bolt carrier),
other arrangements can be used in combination with or independent
of the illustrated configuration. For example, additional apertures
or porting can be used to facilitate the venting of gas if an
adjustment control partially or wholly blocks a gas key's conduit.
Alternatively, an adjustment aperture receiving an adjustment
control can include various bevels or recesses about one or more
edges, or other modifications to ensure unobstructed movement,
airflow, or otherwise prevent damage or malfunctions. In this
regard, alternative or additional adjustment apertures can be
formed on an opposite side of an angled portion of a gas key,
and/or on the top, bottom, or sides of any portion of a gas
key.
[0067] In embodiments, further modifications may be committed to
other components (e.g., porting of a gas tube, modification of a
gas block) to ensure reliable and/or safe functioning of an
autoloading firearm having a gas key with one or more adjustment
apertures.
[0068] While aspects of FIGS. 5-7 are discussed in reference to
single drawings, it is understood that various arrangements or
embodiments are not exclusive, and that aspects can be combined,
substituted, supplemented, et cetera, in various embodiments
without departing from the scope or spirit of the disclosure.
[0069] Turning now to FIG. 8, illustrated is a methodology 800 for
producing an adjustable gas key by forming an adjustment aperture
in a gas key for an autoloading firearm. Methodology 800 begins at
802 and proceeds to 804 where a gas key for an autoloading firearm
cycled at least in part using gas resultant to firing is
provided.
[0070] At 806, an adjustment aperture is formed incident to a
conduit of the gas key. The aperture can be formed in a
prefabricated gas key using a drill, torch, punch or press, chisel,
or other tool or technique known for creating holes in metals or
other suitable materials.
[0071] Various alternative or complementary aspects can also be
included in a method for making an adjustable gas key. For example,
the adjustment aperture may be tapped or threaded to permit a
threaded adjustment control to be inserted. Various other
adjustment controls can be inserted, attached, or formed in or
around the adjustment aperture. A screw, plug, or other adjustment
control can be provided, inserted, or mated. In further aspects, an
internal recess can be formed. In still further embodiments, two or
more adjustment apertures and/or adjustment controls can be formed
or provided in a single gas key.
[0072] Once forming of the adjustment aperture at 806 (and any
subsequent aspects) are complete, methodology 800 ends at 808.
[0073] Turning now to FIG. 9, illustrated is a methodology 900 for
modifying at least one firing characteristic of an autoloading
firearm cycled at least in part with gas produced from firing.
Methodology 900 begins at 902, where the gas flow through a gas key
is modified using an adjustment aperture incident to the conduit
through a gas key.
[0074] In at least one embodiment, gas is permitted to travel
through at least a part of the adjustment aperture at 904 to
reroute the gas from, for example, a carrier interface opening. In
alternative or complementary embodiments, gas is blocked, slowed,
or otherwise restricted at 904 using an adjustment control provided
through at least one adjustment aperture.
[0075] Other aspects of methodology 900 can include opening or
closing an adjustment aperture (partially or completely) and/or
adjusting an adjustment control. For example, the amount of gas
flowing through an adjustment aperture can influence firing
characteristics, and the firing characteristics can be modified,
tuned, or calibrated based on the amount of gas permitted to flow
through the adjustment aperture.
[0076] Similarly, the amount and force of gas reaching a moving
parts assembly through the gas key will influence firing
characteristics, and accordingly the conduit of the gas key can be
partially or wholly blocked (or unblocked) to permit modification,
tuning, and calibration of firing characteristics. Thus, an
adjustment control can be adjusted to effect such blocking or
unblocking. Adjustment can be accomplished through turning (e.g.,
such as with threaded adjustment controls), pushing, pulling, and
other mechanical action in reference to the adjustment control.
[0077] After the aspects described are complete, methodology 900
proceeds to end at 906.
[0078] FIG. 10 illustrates an embodiment of a methodology 1000 for
calibrating a firearm in accordance with techniques herein.
Methodology 1000 begins at 1002 and proceeds to 1004 where a firing
characteristic is modified using an adjustment aperture. The firing
characteristic can be modified by redirecting, venting,
restricting, blocking, or otherwise changing the uninterrupted
transmission of gas through the conduit of a gas key in accordance
with aspects herein.
[0079] At 1006, a determination is made as to whether the firing
characteristic has been modified such that the desired calibration
is achieved. Calibration can include changing the firing, cycling,
and/or associated effects (e.g., felt recoil) without rendering the
autoloading firearm inoperable (e.g., due to insufficient gas
reaching a moving parts assembly to complete a firing cycle
reliably). If the determination at 1006 is negative, methodology
1000 recycles to 1004 where further modifications are completed
using the adjustment aperture (and/or associated adjustment
control).
[0080] If the determination at 1006 returns positive, the
autoloading firearm is calibrated, and methodology 1000 proceeds to
end at 1008.
[0081] Adjustment apertures and adjustment controls herein are
generally depicted as openings or movable components there through
in a gas key for an autoloading firearm. However, upon review of
these disclosures, other mechanisms for modifying gas flow through
a bolt carrier group will be apparent. For example, a shutter or
other movable portion could be movably provided above, below, or
directly on carrier interface opening 122, or at other portions of
conduit 132. Different constricting mechanisms or gas keys with
conduits of varying or smaller cross-sectional size can be employed
to similar effect. Such alternatives are within the scope and
spirit of the disclosure, one result of which is to modify firing
characteristics of an autoloading firearm based on modifications to
the flow of gases through the use of components housed within the
upper receiver of the firearm.
[0082] While principles and modes of operation have been explained
and illustrated with regard to particular embodiments, it must be
understood, however, that this may be practiced otherwise than as
specifically explained and illustrated without departing from its
spirit or scope.
* * * * *