U.S. patent application number 14/145739 was filed with the patent office on 2015-07-02 for muzzle device for firearm having a gas operating system.
The applicant listed for this patent is Sergey Monveldt. Invention is credited to Sergey Monveldt.
Application Number | 20150184960 14/145739 |
Document ID | / |
Family ID | 53481295 |
Filed Date | 2015-07-02 |
United States Patent
Application |
20150184960 |
Kind Code |
A1 |
Monveldt; Sergey |
July 2, 2015 |
Muzzle Device for Firearm Having a Gas Operating System
Abstract
A muzzle device for a firearm comprising a body having a barrel
mounting portion and a combustion gas receiving portion, wherein
the barrel mounting portion is arranged to mount the muzzle device
to a muzzle end of a barrel of the firearm such the combustion gas
receiving portion of the muzzle device extends distally from the
muzzle end of the barrel, and wherein the combustion gas receiving
portion is arranged to capture combustion gas from the barrel of
the firearm and provide the combustion gas back to a receiver of
the firearm through a combustion gas return tube.
Inventors: |
Monveldt; Sergey; (South
Hadley, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Monveldt; Sergey |
South Hadley |
MA |
US |
|
|
Family ID: |
53481295 |
Appl. No.: |
14/145739 |
Filed: |
December 31, 2013 |
Current U.S.
Class: |
89/193 |
Current CPC
Class: |
F41A 5/26 20130101; F41A
21/32 20130101 |
International
Class: |
F41A 5/26 20060101
F41A005/26 |
Claims
1. A muzzle device for a firearm, comprising: a body comprising a
barrel mounting portion and a combustion gas receiving portion; the
barrel mounting portion to mount the muzzle device to a muzzle end
of a barrel of the firearm such that the combustion gas receiving
portion of the muzzle device extends distally from the muzzle end
of the barrel; and the combustion gas receiving portion arranged to
capture combustion gas from the barrel of the firearm and provide
the combustion gas back to a receiver of the firearm through a
combustion gas return tube.
2. The device of claim 1 wherein: the combustion gas receiving
portion includes a combustion gas chamber and a combustion gas
outlet port; and the combustion gas outlet port arranged to receive
combustion gas directly from the combustion gas chamber and provide
the combustion gas directly to an inlet port of the combustion gas
return tube.
3. The device of claim 2 wherein: the combustion gas outlet port is
arranged adjacent a rear wall of the combustion gas chamber.
4. The device of claim 2 wherein: the combustion gas outlet port is
part of a through-bore formed in the body.
5. The device of claim 2 wherein: a distal end of the combustion
gas chamber is defined by a transverse wall of the body; and the
transverse wall has an arcuate inner surface.
6. The device of claim 5 wherein: the barrel of the firearm has a
bore with a diameter; the transverse wall defines a projectile
orifice for a projectile fired by the firearm to exit the muzzle
device, the projectile orifice being circular and having a
diameter; and the projectile orifice diameter is greater than the
bore diameter in a range of 1.1 to 1.3 times the bore diameter.
7. The device of claim 1 wherein: the combustion gas receiving
portion includes a combustion gas chamber and exactly two outlets
for the combustion gas; and the two outlets provided by a
combustion gas outlet port arranged to receive combustion gas
directly from the combustion gas chamber and provide the combustion
gas directly to an inlet port of the combustion gas return tube,
and a projectile orifice arranged at a distal end of the body.
8. The device of claim 1 wherein: the body comprises a main body
and an end cap.
9. The device of claim 8 wherein: the main body and the end cap are
connected by a mechanical connection.
10. The device of claim 9 wherein: the main body and the end cap
are connected by threaded engagement.
11. The device of claim 8 further comprising: a retaining device
which inhibits the main body and the end cap from rotating relative
to one another.
12. The device of claim 11 wherein: the retaining device comprises
a end cap retaining pin mounted in the main body which is
configured to be urged into a detent formed in the end cap.
13. The device of claim 12 wherein: the end cap retaining pin is
spring biased by a linear spring.
14. The device of claim 1 wherein: the body comprises a bore to
receive the combustion gas return tube.
15. The device of claim 1 further comprising: a retaining device
which inhibits the body and the combustion gas return tube from
separating relative to one another.
16. The device of claim 15 wherein: the retaining device comprises
a combustion gas return tube retaining pin.
17. The device of claim 1 wherein: the barrel mounting portion is
threaded.
18. The device of claim 1 wherein: the barrel mounting portion
comprises a bore to receive a distal end portion of the barrel.
19. The device of claim 1 further comprising: a retaining device
which inhibits the body and the barrel from rotating relative to
one another.
20. The device of claim 19 wherein: the retaining device comprises
a barrel retaining pin.
Description
FIELD
[0001] The present disclosure relates to relates to firearms, and
more particularly relates to gas operated semi-automatic and
automatic firearms.
BACKGROUND
[0002] Certain semi-automatic and automatic firearms, such as the
family of AR-15/M-16 firearms, may operate with a direct gas
impingement system, which may be understood as a type of gas
operation system.
[0003] The direct gas impingement system directs hot propellant
combustion gas from a fired cartridge directly to a bolt carrier or
slide assembly to cycle the action of the firearm. More
particularly, propellant combustion gas from the barrel of the
firearm travels through a combustion gas outlet port formed in the
barrel, and subsequently into a combustion gas return tube which
delivers the propellant combustion gas into the upper receiver of
the AR-15/M-16 firearm during operation. Propellant combustion gas
is vented into the upper receiver as the bolt carrier assembly is
driven aft and separates from the combustion gas return tube.
[0004] Unlike gas piston operated firearms, direct impingement does
not require a separate gas cylinder, piston, and operating rod
assembly. By having high-pressure propellant gas act directly upon
the bolt and carrier, the AR-15/M-16 firearms may be provided with
lower weight and lower cost than a gas piston operated firearm.
[0005] Unfortunately, one problem of the direct gas impingement
system is that the firearm becomes fouled more quickly. The venting
of the propellant combustion gas becomes a problem because the
propellant combustion gas carries contaminates such as vaporized
metals, carbon and gaseous residues which may contact cooler
operating parts of the firearm and condense thereon. The deposits
may then increase friction on the bolt's camming system, which may
lead to jamming.
[0006] As a result, thorough and frequent cleaning of the upper and
lower receivers of AR-15/M-16 firearms is required to better ensure
reliability. Furthermore, components of the direct gas impingement
system outside the receivers, such as the combustion gas outlet
port of the barrel, the combustion gas block and the combustion gas
return tube used to deliver the combustion gas into the receiver
area, must also be thoroughly cleaned. When these components,
certain of which may be difficult to access and clean, become
constricted over time, such may result in a lower gas pressure
acting on the bolt and carrier which may be insufficient to cycle
the action of the firearm, and once again result in jamming.
[0007] In addition to the combustion gas outlet port on the barrel
becoming fouled, another problem with the AR-15/M-16 firearms has
been the specific location of the combustion gas outlet port for
the direct gas impingement system to operate properly. The direct
gas impingement system of AR-15/M-16 firearms may be understood to
have been originally designed for a rifle length barrel having a
barrel length of about 20 inches. The barrel includes a combustion
gas outlet port formed at about 12.5 inches from the receiver,
leaving a barrel length of about 7.5 inches after the combustion
gas outlet port, which may be understood as the gas-port-to-muzzle
length of the barrel. With the foregoing arrangement, the pressure
of the combustion gas passing through the combustion gas outlet
port to cycle the action of the AR-15/M-16 rifle peaks in a range
of 20,000 to 25,000 psi.
[0008] Over the years, the AR-15/M-16 barrel has gotten shorter as
manufacturers have sought to configure the AR-15/M16 rifle to fit
different end user needs, such as by providing both carbine and
pistol versions. Unfortunately, shortening the barrel of the
AR-15/M16 firearms and changing the location of the combustion gas
outlet port results on changing the operation of the direct gas
impingement system. The placement and size of the combustion gas
outlet port, as well as the length of the barrel between the
combustion gas outlet port and the terminal (muzzle) end of the
barrel, i.e. the gas-port-to-muzzle length, are an integral part of
the operating system design.
[0009] More particularly, the distance of the combustion gas outlet
port from the firing chamber, along with the diameter of the barrel
interior, the charge of the cartridge and the size of the gas port,
largely determine the combustion gas pressure entering the
combustion gas outlet port as the projectile passes the outlet
port. Furthermore, the distance of the combustion gas outlet port
from the firing chamber and the distance of the gas path back to
the bolt carrier determines the initial gas timing, while the
distance from the gas outlet port to the end of the barrel, i.e.
the gas-port-to-muzzle length, determines the duration of the gas
system pressure.
[0010] Thus, given that combustion gas pressure drops as the
projectile travels down the barrel, if the combustion gas outlet
port is placed too far aft in the barrel, the combustion gas
pressures may be greater than necessarily to cycle the action, and
may result in premature wear and other damage to the firearm. On
the other hand, if the combustion gas outlet port is placed too far
down the barrel, the combustion gas pressures may not be sufficient
to cycle the action, or of long enough duration (combustion gas
pressure in the barrel drops to zero when the projectile exits the
barrel) to cycle the action.
[0011] More particularly, the time the projectile remains in the
barrel, after passing the combustion gas port, may be referred to
as the "dwell" or "dwell time." Thus, dwell, or dwell time, may be
understood as the period that the gas operating system maintains
pressure to continue the cycling of the firearm. For a conventional
AR-15/M-16, the dwell may be measured from the time the projectile
passes the combustion gas outlet port in the barrel to the time the
projectile exits the barrel terminal (muzzle) end. Consequently, if
the combustion gas outlet port is placed too far down the barrel,
resulting in insufficient dwell period, the combustion gas
pressures will not have sufficient time to cycle the action.
[0012] In contrast to an AR-15/M-16 rifle, for an AR-15/M-16
carbine with a barrel length of about 14.5 inches, the
gas-port-to-muzzle length is about 7 inches. As a result, it may be
understood that the combustion gas outlet port is about 7.5 inches
from the receiver. Such a gas system arrangement may be referred to
as a carbine-length gas system, which may be used for barrel
lengths of 10 to 18 inches. With the foregoing arrangement, the
pressure of the combustion gas passing through the combustion gas
outlet port for the AR-15/M-16 carbine peaks in a range of 30,000
to 35,000 psi.
[0013] Consequently, all things being equal, as a result of the
combustion gas outlet port being moved aft, the combustion gas
pressures experienced by the AR-15/M-16 carbine during cycling of
the action are significantly increased as compared to the
AR-15/M-16 rifle, which may be understood to place greater stress
on the AR-15/M-16 carbine, and the potential for greater wear as
well as damage.
[0014] Moreover, the combustion gas operating pressures are
significantly greater as the barrel continues to get shorter. For
example, for an AR-15/M-16 pistol with a barrel length of about 7.5
inches, the gas-port-to-muzzle length is about 3 inches. As a
result, it may be understood that the combustion gas outlet port is
about 4.5 inches from the receiver. Such a gas system arrangement
may be referred to as a pistol-length gas system, which may be used
for barrel lengths under 10 inches. With the foregoing arrangement,
the pressure of the combustion gas passing through the combustion
gas outlet port for the AR-15/M-16 pistol peaks in a range of
50,000 to 55,000 psi.
[0015] As a result, for AR-15/M-16 pistol with a 7.5 inch barrel,
the combustion gas pressures experienced by the pistol during
cycling the action may be understood to be significantly greater
than even those of the AR-15/M-16 carbine. Furthermore, the dwell
may be expected to be significantly lower as the gas-port-to-muzzle
length is about 3 inches as opposed to the 7 inch
gas-port-to-muzzle length of the AR-15/M-16 carbine. As a result,
the AR-15/M-16 pistol must not only cycle with significantly
greater operating pressures while cycling the action, but also must
cycle the action faster.
[0016] Unfortunately, the higher operational pressures associated
with the AR-15/M-16 carbine, and more particularly the AR-15/M-16
pistol, may result in the use of heavier duty/heavier weight
components. Such may also result in decreased reliability and a
decreased useful life of the firearm. Furthermore, the AR-15/M-16
carbine, and more particularly the AR-15/M-16 pistol, may be
understood to suffer from greater fouling issues given the shorter
length of the gas impingement system.
[0017] What is needed is a direct gas impingement system to cycle
the action of a shorter barrel firearm, such as the AR-15/M-16
carbine and the AR-15/M-16 pistol, at lower pressure/forces which
results in placing less stress on the firearm, as well a gas
operating system which offers increased ability to clean the
firearm of combustion gas contaminates.
SUMMARY
[0018] A muzzle device for a firearm is provided, with the muzzle
device comprising a body having a barrel mounting portion and a
combustion gas receiving portion, wherein the barrel mounting
portion is arranged to mount the muzzle device to a muzzle end of a
barrel of the firearm such the combustion gas receiving portion of
the muzzle device extends distally from the muzzle end of the
barrel, and wherein the combustion gas receiving portion is
arranged to capture combustion gas from the barrel of the firearm
and provide the combustion gas back to a receiver of the firearm
through a combustion gas return tube.
FIGURES
[0019] The above-mentioned and other features of this disclosure,
and the manner of attaining them, will become more apparent and
better understood by reference to the following description of
embodiments described herein taken in conjunction with the
accompanying drawings, wherein:
[0020] FIG. 1 is a side view of a firearm according to the present
disclosure;
[0021] FIG. 2 is a front perspective view of the firearm of FIG.
1;
[0022] FIG. 3 is a bottom perspective view of the firearm of FIG.
1;
[0023] FIG. 4 is a rear perspective view of the firearm of FIG.
1;
[0024] FIG. 5 is a top view of the upper receiver of the firearm of
FIG. 1;
[0025] FIG. 6 is a cross-sectional side view of the upper receiver
of the firearm of FIG. 1 taken along line 6-6 of FIG. 5;
[0026] FIG. 7A is a close-up cross-sectional side view of the
distal end portion of the upper receiver of FIG. 6 bounded by
circle B which includes a muzzle device according to the
present;
[0027] FIG. 7B is a close-up cross-sectional side view of the
distal end portion of the upper receiver of FIG. 6 bounded by
circle B which includes the muzzle device of FIG. 7A with a
projectile and combustion gas therein;
[0028] FIG. 8 is a close-up front perspective view of a main body
of a muzzle device according to the present disclosure;
[0029] FIG. 9 is a close-up rear perspective view of the main body
of FIG. 8;
[0030] FIG. 10 is a longitudinal cross-sectional view of the main
body of FIG. 8;
[0031] FIG. 11 is a cross-sectional view of the main body of FIG.
10 taken along line 11-11;
[0032] FIG. 12 is a cross-sectional view of the main body of FIG.
10 taken along line 12-12;
[0033] FIG. 13 is a close-up front perspective view of an end cap
of a muzzle device according to the present disclosure;
[0034] FIG. 14 is a close-up rear perspective view of the end cap
of FIG. 13;
[0035] FIG. 15 is a front view of the end cap of FIG. 13;
[0036] FIG. 16 is a cross-sectional view of the end cap of FIG. 15
taken along line 16-16; and
[0037] FIG. 17 is a cross-sectional view of a barrel and gas tube
assembled with a gas block of the prior art.
DETAILED DESCRIPTION
[0038] It may be appreciated that the present disclosure is not
limited in its application to the details of construction and the
arrangement of components set forth in the following description or
illustrated in the drawings. The invention(s) herein may be capable
of other embodiments and of being practiced or being carried out in
various ways. Also, it may be appreciated that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting as such may be understood by one
of skill in the art.
[0039] Referring now to FIGS. 1-4, there is shown a firearm 100
which may include a muzzle device 140 according to the present
disclosure. As shown, the firearm 100 may comprise a gas-operated
semi-automatic or automatic firearm, and more particularly a direct
gas impingement gas-operated semi-automatic or automatic firearm.
As explained in greater detail below, with a direct gas impingement
gas-operated firearm, the direct gas impingement system may be
understood to direct hot propellant combustion gas from a fired
cartridge directly to the bolt carrier or slide assembly of the
receiver to cycle the action of the firearm.
[0040] Even more particularly, firearm 100 may be a member of the
family of AR-15/M-16 firearms, which may include the AR-10, AR-15,
M16, M16A1, M16A2, M16A3, M16A4, M4, M4A1, CAR-15, etc.
Furthermore, firearm 100 may be categorized as a rifle, a carbine,
a mid-length or a pistol, particularly depending on barrel length.
As shown in FIG. 1, firearm 100 is shown to be an AR-15/M-16 pistol
with a shoulder stock, particularly configured to operate with the
5.56.times.45 mm NATO military cartridge. Other exemplary calibers
may include the 5.56/.223 Remington, 300 Blackout, 0.308
Win/7.62.times.51, 5.45.times.39, 7.62.times.39, 458 SOCOM, and
0.50 Beowulf.
[0041] As best shown in FIGS. 1 and 3, firearm 100 comprises a
receiver which may be sectioned into a lower receiver 110 and an
upper receiver 120. The lower receiver 110 includes the fire
control group, grip and butt (shoulder) stock assembly. The upper
receiver 120 includes the barrel, bolt carrier group, charging
handle, sights, gas system and muzzle device.
[0042] Referring now to FIGS. 5 and 6, there is shown the upper
receiver 120 of firearm 100 including barrel 130 and muzzle device
140 according to the present disclosure.
[0043] As best shown in FIG. 7A, barrel 130 of firearm 100 includes
a bore 132 defined by barrel wall 133. A distal end stepped portion
134 of the barrel wall 133 decreases in thickness and diameter via
a step down such that a narrow (neck) portion 135 is created at the
distal end of the barrel 130. As shown, the narrow (neck) portion
135 terminates proximally at shoulder 136. As used herein, it
should be understood that the terms "proximal" and "distal" are
made in reference to the longitudinal length of firearm 100 with
the muzzle device 130 being at the distal end of the firearm 100,
and the butt/stock being at the proximal end of the firearm
100.
[0044] A muzzle device 140, which extends distally relative to the
barrel terminal (muzzle) end 137, mounts to firearm 100,
particularly the barrel 130 thereof. As shown in FIG. 7, as well as
FIGS. 8-16 which provide additional views, muzzle device 140
comprises a hollow body 141 which, as shown, may further comprise a
main body 142 and an end cap 180. Thus, it should be understood
that while body 141 may be shown as two separate pieces
particularly provided by main body 142 and end cap 180, body 141
may alternatively be formed as a single unitary (monolithic) piece.
Body 141, and more particularly main body 142 and end cap 180, may
be fabricated from a suitable gun metal.
[0045] Body 141 comprises a barrel mounting portion 144 and a
combustion gas receiving portion 156. As such, barrel mounting
portion 144 mounts the muzzle device 140 to the barrel terminal
(muzzle) end 137 of a barrel 130 of the firearm 100 such that the
combustion gas receiving portion 156 of the muzzle device 140
extends distally from the barrel terminal (muzzle) end 137 of the
barrel 130.
[0046] As shown, barrel mounting portion 144 is provided by main
body 142. Barrel mounting portion 144 is adapted to removably
connect muzzle device 140 to barrel 130. As shown, due to the
deceased outer size (diameter) of barrel mounting portion 144
relative to combustion gas receiving portion 156, a shoulder 145 is
provided with combustion gas receiving portion 156, into which
combustion gas return tube 220 extends.
[0047] Barrel mounting portion 144 includes a longitudinally
oriented barrel mounting bore 146, which more particularly
comprises a counter-bore which is defined by sidewall 147 of barrel
mounting portion 144, which receives the distal end stepped portion
134 of barrel 130. As shown, the narrow (neck) portion 135 of the
barrel 130 connects with the narrow portion 148 of the counter-bore
146 via threaded engagement. More particularly, external (male)
threads 138 of narrow (neck) portion 135 of the barrel 130
threadably engage with the internal (female) threads 150 of the
narrow portion 148 of the counter-bore 146.
[0048] Once the barrel 130 and the barrel mounting portion 144 of
the muzzle device 140 are suitably secured and properly oriented to
one another, such are secured in position by a removable retaining
device. As shown, the removable retaining device comprises a
tapered, cylindrical (barrel) retaining pin 152 which is inserted
into a tapered, cylindrical through-hole formed by opposing
semi-circular recesses 139 and 154 formed in the barrel 130 and the
barrel mounting portion 144, respectively. As shown, the opposing
semi-circular recesses 139 and 154 are formed transverse to the
longitudinal axis L of the barrel 130 and the muzzle device
140.
[0049] The barrel retaining pin 152 thereafter holds the barrel 130
and the barrel mounting portion 144 of the muzzle device 140 in
stationary, secured position and inhibits the barrel 130 and the
main body 142 of muzzle device 140 from rotating relative to one
another. More particularly, the barrel retaining pin 152 inhibits
the main body 142 of muzzle device 140 from rotating relative to
the barrel 130.
[0050] As set forth above, muzzle device 140 further comprises a
combustion gas receiving portion 156, which is formed by body 141,
and more particularly main body 142 and end cap 180. The combustion
gas receiving portion 156 is arranged to capture combustion gas
expelled from the barrel 130 of the firearm 100 and provide the
combustion gas back to receiver, here upper receiver 120 of the
firearm 100, through combustion gas return tube 220. The combustion
gas is then used to cycle the action of firearm 100. As explained
in greater detail below, combustion gas receiving portion 156
comprises an enlarged combustion gas (burn) chamber 157 which is
provided by cavity 158 formed in main body 142 and cavity 194
formed in end cap 180. As explained in greater detail below, for
the 5.56.times.45 mm cartridge with a 7.5 inch barrel, the volume
of the combustion gas (burn) chamber 157 is in a range of 2 to 3
times greater than the volume of the bore 132 of barrel 130, and
more particularly 2.5 times greater than the volume of the bore 132
of barrel 130, with the volume of the combustion gas (burn) chamber
157 being about 0.68 in.sup.3 (cu in.) and the volume of the bore
132 of barrel 130 being 0.3 in.sup.3 (cu in.).
[0051] As shown, counter-bore 146 of barrel mounting portion 144
opens into cavity 158 of main body 142. As such, the bore 132 of
barrel 130 is in fluid communication with cavities 158 and 194 of
main body 142 and end cap 180, respectively.
[0052] Combustion gas (burn) chamber 157 is formed by a
longitudinally orientated surrounding (annular) sidewall 160 of the
main body 142, which extends to and defines the distal end 162 of
the main body 142. Combustion gas (burn) chamber 157 is also formed
by a transverse end wall 182 of end cap 180. As shown, the inner
contour of the end cap 180 includes an arcuate concave inner gas
impingement surface 185 which defines cavity 194, and forms part of
the combustion gas (burn) chamber 157. As shown, end cap 180
further includes a center, circular (projectile) orifice 186 which
is formed by transverse wall 182, through which a projectile passes
upon the firing of firearm 100. For the 5.56.times.45 mm cartridge,
the center (projectile) orifice 186 has a diameter which is in a
range of 1.1 to 1.3 times greater than the diameter of the bore 132
of barrel 130, and more particularly 1.2 times greater than the
diameter of the bore 132 of barrel 130, with the diameter of the
center (projectile) orifice 186 having a diameter of 0.272 inch and
the bore 132 having a diameter of 0.223 inch.
[0053] End cap 180 removably connects to the main body 142 at the
distal end thereof, particularly by a mechanical connection. More
particularly, main body 142 and end cap 180 connect by threaded
engagement. Even more particularly, external (male) threads 184 on
sidewall 181 of end cap 180 threadably engage with the internal
(female) threads 164 on sidewall 160 of the main body 142.
[0054] The end cap 180 may further include a perimeter circular
shoulder 188 which extends distally relative to the transverse end
wall 182, which results in a circular recess 192 being formed in
the outer contour of the end cap 180. As shown, the bottom of the
circular recess 192, which is formed by the outer surface 183 of
the transverse wall 182, is planar. The distal end of the
peripheral wall may include a plurality of pointed raised
projections 190, which may be used to shatter glass.
[0055] Along an upper side of the muzzle device 140 (along the top
of the firearm 100), the combustion gas receiving portion 156 of
main body 142 further includes a longitudinally oriented bore 166,
which more particularly comprises a counter-bore, which is formed
in the shoulder 145 of sidewall 160 of main body 142.
[0056] As shown, counter-bore 166 contains an end cap retaining pin
200, a spring 210 and a combustion gas return tube 220. A shaft 204
of the end cap retaining pin 200 extends through the narrow distal
portion 168 of the counter-bore 166, while a head 202 of the end
cap retaining pin 200 is retained in the wider proximal portion 170
of the counter-bore 166. A distal end portion of shaft 204 may
enter a detent 189 of the end cap 180 to inhibit the end cap 180
from rotating relative to the main body 142.
[0057] After end cap retaining pin 200 is inserted in counter-bore
166, spring 210 is then inserted into wider proximal portion 170 of
the counter-bore 166, with one end thereof in contact with the head
202 of the end cap retaining pin 200. After spring 210 is inserted
into the counter-bore 166, combustion gas return tube 220 is
inserted into counter-bore 166 with a distal end of the combustion
gas return tube 220 in contact with the opposing end of spring
210.
[0058] Combustion gas return tube 220 is adapted to removably
connect to muzzle device 140. Once the combustion gas return tube
220 is properly positioned and orientated in counter-bore 166, a
transverse through hole formed in the combustion gas return tube
220 aligns with a transverse through hole formed in the main body
142. A removable retaining device such as a removable retaining pin
172 is then inserted into the two holes which holds the combustion
gas return tube 220 and the main body 142 in stationary position
and inhibits the combustion gas return tube 220 and the main body
142 from separating and rotating relative to one another. More
particularly, the retaining pin 172 inhibits the combustion gas
return tube 220 from rotating relative to the main body 142. The
retaining pin 172 may be threaded, such as that of a screw.
[0059] Furthermore, with the foregoing construction, when linear
spring 210 is compressed within bore 170, end cap retaining pin 200
provides a removable retaining device mounted in the main body 142
which is urged into detent 189 in end cap 180 by the decompression
force of the spring 210. As such, during assembly of end cap 180 to
main body 142, end cap retaining pin 200 may first be pushed into
bore 168 at the distal end thereof (e.g. by the distal end of a
flat screw driver), such that the end cap retaining pin 200 is
barely exposed. End-cap 180 may be rotated (e.g. threaded
clockwise) on to main body 142. When end-cap 180 has been
sufficiently threaded onto main body 142, the retracted position of
end cap retaining pin 200 may be released such that the distal end
of the end cap retaining pin 200 contacts shoulder 188. Thereafter,
with continued rotation of end-cap 180, the end cap retaining pin
200 will be urged into the next detent 189 which passes by the
distal end of the end cap retaining pin 200 by the decompression
(bias) force of spring 210, thus inhibiting the end cap 180 from
further rotating relative to the main body 142.
[0060] When it is desirable to remove end-cap 180 from main body
142, end cap retaining pin 200 may then again be held in a
retracted position and end-cap 180 rotated (e.g. threaded
counter-clockwise) until end-cap 180 separates from main body
142.
[0061] Alternatively, the end cap retaining pin 200 and the shape
of the detent 189 may be such that when end-cap 180 is rotated onto
main body 142, the shoulder 188 of the end-cap 180 forces the end
cap retaining pin 200 to retract without need of a separate
tool.
[0062] As shown, combustion gas return tube 220 includes a
combustion gas return tube bore 222 defined by combustion gas
return tube wall 224. Combustion gas return tube 220 further
includes a combustion gas inlet port 226 formed as a cylindrical
aperture located in the wall 224 of combustion gas return tube 220.
Combustion gas inlet port 226 is in fluid communication with a
combustion gas outlet port 159 formed in main body 142, which is
formed adjacent a rear wall 161 of the combustion gas (burn)
chamber 157, which is shown to be planar. Moreover, as shown,
combustion gas outlet port 159 is actually part of through-bore
174, which permits easily cleaning of gas outlet port 159 when
combustion gas return tube 220 is removed from counter-bore 166.
Combustion gas outlet port 159 and combustion gas inlet port 226
may have a diameter in a range of 0.100 inch to 0.110 inch and more
particularly 0.0.104 inch.
[0063] Thus, the combustion gas receiving portion 156 includes a
combustion gas (burn) chamber 157 and a combustion gas outlet port
159, with the combustion gas outlet port 159 arranged to receive
combustion gas directly from the combustion gas (burn) chamber 157
and provide the combustion gas directly to combustion gas inlet
port 226 of the combustion gas return tube 220.
[0064] More particularly, the combustion gas receiving portion 156
includes a combustion gas (burn) chamber 157 and exactly two
outlets for the combustion gas, with the two outlets provided by
the combustion gas outlet port 159 arranged to receive combustion
gas directly from the combustion gas (burn) chamber 157 and provide
the combustion gas directly to an inlet port 226 of the combustion
gas return tube 220, and a projectile orifice 186 arranged at a
distal end of the body 141.
[0065] As set forth above, firearm 100 may comprise a gas-operated
semi-automatic or automatic firearm, and more particularly a direct
gas impingement gas-operated firearm in which the direct gas
impingement system directs hot propellant combustion gas from a
fired cartridge directly to the bolt carrier or slide assembly of
the upper receiver 120 to cycle the action of the firearm 100.
[0066] More particularly, as shown in FIG. 7B, propellant
combustion gas from the bore 132 of barrel 130 is received into
combustion gas (burn) chamber 157. Without being bound to a
particular theory, it is believed that as soon as projectile 250
clears the barrel terminal (muzzle) end 137, the hot propellant
combustion gas, as shown by the arrows, will expand on either side
of the projectile 250 to the size of the combustion gas (burn)
chamber 157. A portion of the combustion gas may then follow the
arcuate surface 185 of end cap 180 and be redirected proximally due
to the curvature of surface 185. This may be understood to increase
the pressure in combustion gas (burn) chamber 157, along with the
dwell.
[0067] Due to the pressure in combustion gas (burn) chamber 157,
the combustion gas then travels through combustion gas outlet port
159 into combustion gas inlet port 226 and into combustion gas
return tube bore 222 of combustion gas return tube 220. As best
shown in FIG. 6, combustion gas return tube 220 delivers the
propellant combustion gas into the upper receiver 130 of firearm to
cycle the action. Propellant combustion gas is vented into the
upper receiver 130 as the bolt carrier assembly is driven aft and
separates from the combustion gas return tube 220. With the
foregoing construction of firearm 100, certain advantages are
realized over the art.
[0068] With a conventional AR-15/M-16 rifle, shown as firearm 10 in
FIG. 17, propellant combustion gas from the bore 32 of barrel 30
travels into a combustion gas outlet port 36 formed the barrel 30.
Thereafter, the combustion gas travels into a gas transfer port 44
located in a gas block 40 mounted on top of the barrel 30. From the
gas transfer port 44 of the gas block 40, the combustion gas then
travels into combustion gas inlet port 56 and combustion gas return
tube bore 52 of combustion gas return tube 50. In addition to the
gas block 50, the barrel 30 includes a flash hider 60 mounted to
the barrel terminal (muzzle) end 37.
[0069] In contrast to the prior art, the muzzle device 140 of the
present disclosure eliminates the need for a separate gas block 40,
as well as a combustion gas outlet port 36 being formed in the wall
34 of the barrel 30 as known in the art, which must be precision
drilled and finished. Furthermore, the muzzle device 100 of the
present disclosure does not encounter the cleaning concerns
encountered with a combustion gas outlet port 36 formed in the
barrel 30. As set forth above, propellant combustion gas may be
understood to carry contaminates such as vaporized metals, carbon
and residues. As such, these contaminates may foul the gas out port
36 formed in barrel 30, which may lead to erosion as well as
inadvertent damage to the barrel 30 during cleaning, such as by
scratching the barrel rifling or otherwise damaging the bore 32,
which both shorten barrel life. In contrast, with the muzzle device
100 of the present disclosure eliminating the combustion gas outlet
port 36 formed in barrel 30, there is no risk of damaging the bore
132 in such a similar manner.
[0070] Also importantly, muzzle device 100 does not need remain
with the firearm 100 during cleaning thereof. In other words,
muzzle device 100 may be removed from the barrel 130 to be cleaned,
and simply replaced with a second muzzle device 100 while the first
muzzle device 100 is thereafter being cleaned. The present
disclosure provides for removing muzzle device 140 from firearm 100
by simple mechanical disconnection from the barrel 130 and
combustion gas return tube 220.
[0071] In contrast, with combustion gas outlet port 36 formed in
barrel 30 of a firearm 10 of the prior art, such must generally be
cleaned with the remainder of the firearm 10, unless the firearm 10
is substantially broken down to remove the barrel 30. In either
case, cleaning gas outlet port 36 formed in barrel 30 of firearm 10
may be understood to take longer than removing and replacing muzzle
device 140 on firearm 100. As such, firearm 100 may be made more
readily available in emergency situations.
[0072] In addition, the amount of contaminates received into the
receiver 130 of firearm 100 may be reduced with use of muzzle
device 100 as compared to a prior art gas operating system which
makes use of a gas out port 36 formed in the barrel 30. Due to the
large surface area of the combustion gas (burn) chamber 157,
certain contaminates within the combustion gas may collect in the
combustion gas (burn) chamber 157 rather than passing through the
combustion gas outlet port 159 and combustion gas return tube 220
to receiver 130. Moreover, contaminates which may be captured in
may be easily removed from the combustion gas (burn) chamber 157
simply be removing end cap 180 from main body 142 and cleaning the
combustion gas (burn) chamber 157.
[0073] Furthermore, combustion gas (burn) chamber 157 may also
operate as a flash suppressor. While not being bound to a
particular theory, rifle flash may be understood to be created by
excess powder burning when it comes into contact with air after the
projectile leaves the bore of the barrel. As such, a flash
suppressor may be understood to reduce the flash which may occur as
the projectile leaves the firearm, particularly to protect the
shooter's eyesight from a quick change in brightness, thus keeping
the target in sight and permitting follow-up shots. With combustion
gas (burn) chamber 157, excess power may be trapped in therein,
where it may remain until the combustion gas (burn) chamber 157 is
cleaned or such burns with sufficient heat.
[0074] Moreover, muzzle device 100 may enable the a firearm 100,
such as an AR-15/M-16 carbine, and more particularly an AR-15/M-16
pistol, to make use of a longer gas system to reduce the operating
pressures during the cycling of the action. For example, muzzle
device 100 may enable an AR-15/M-16 carbine to make use of a
rifle-length gas system, and my enable an AR-15/M-16 pistol to make
use of a carbine-length gas system. Furthermore, the combustion gas
(burn) chamber 157 may mediate the pressure spike and smooth out
the action thus reducing wear.
[0075] With the present disclosure, it has been found that, due to
the cross-sectional increase of the combustion gas (burn) chamber
157 as compared to the bore 132 of barrel 130, the longitudinal
distance between the combustion gas outlet port 159 and the end cap
center (projectile) orifice 186 may be greatly shortened (as
compared to the longitudinal distance between the combustion gas
outlet port 36 and the barrel terminal (muzzle) end 37 of a
traditional AR-15/M-16 of FIG. 17), while maintaining the necessary
dwell to operate the firearm 100. Furthermore, the use of
combustion gas (burn) chamber 157 has been found to provide a
smoother, softer cycling of the action of firearm 100 and mediate
the pressure spike of the fired projectile.
[0076] In order to provide the necessary dwell for muzzle device
100, after a certain amount of testing, for a AR-15/M-15
5.56.times.45 mm cartridge and a 7.5 inch barrel, the volume of the
combustion gas (burn) chamber 157 was sized to be equivalent to the
volume of the bore 32 of a rifle barrel 30 of about 18 inches, such
resulting in a total volume equal to that of a 25 inch barrel when
the 7.5 inch pistol barrel is added thereto. As set forth above,
the volume of the combustion gas (burn) chamber 157 is about 2.5
times greater than the volume of the bore 132 of barrel 130, with
the volume of the combustion gas (burn) chamber 157 being about
0.68 in.sup.3 (cu in.) and the volume of the bore 132 of barrel 130
being 0.3 in.sup.3 (cu in.).
[0077] As set forth above, for an AR-15/M-16 pistol with a barrel
length of about 7.5 inches, the conventional gas-port-to-muzzle
length is about 3 inches, and the combustion gas outlet port is
about 4.5 inches from the receiver. Furthermore, the end of the
barrel generally includes a conventional flash hider attached
thereto, making the overall barrel length about 10 inches.
[0078] However, when the muzzle device 140 of the present
disclosure replaces a conventional flash hider, the combustion gas
return tube 220 is now mounted to the muzzle device 140 and no
longer the barrel 130. As such, given that the barrel length about
7.5 inches for an AR-15/M-16 pistol, it is now possible to mount a
carbine-length gas system to the AR-15/M-16 pistol, whereby the
combustion gas outlet port 159 is now about 7.5 inches from the
receiver.
[0079] As a result of the combustion gas return tube 220 now being
mounted to the muzzle device 140 and no longer to the barrel 130,
the gas operational pressures of the AR-15/M-16 pistol are
decreased particularly given the combustion gas outlet port 159 is
moved distally. As a result, the stress on the firearm 100 during
firing and the potential for wear as well as damage are all
decreased. More particularly, with use of muzzle device 140, the
pressure of the combustion gas passing through the combustion gas
outlet port 159 for the AR-15/M-16 pistol drops from a peak of
about 50,000 psi to about 20,000 psi, which is comparable to an
AR-16/M-16 rifle. Moreover, the gas pressure in the gas return tube
220 going to the bolt may be in a range of 8,000 psi. to 12,000
psi., and more particularly in a range of 9,000 psi to 10,000
psi.
[0080] Such a gas pressure in the gas return tube 220 (of 9,000 psi
to 10,000 psi.) may be achieved with the foregoing relationship
between the combined the volume of the bore 132 of barrel 130 and
volume of the combustion gas (burn) chamber 157 and the diameter of
the combustion gas outlet port 159/combustion gas inlet port 226
having in a range of 0.100 inch to 0.110 inch and more particularly
0.0.104 inch. The pressure may be measured using any of the known
techniques, including the copper crusher method, piezo method and
strain gauge method.
[0081] While a preferred embodiment of the present invention(s) has
been described, it should be understood that various changes,
adaptations and modifications can be made therein without departing
from the spirit of the invention(s) and the scope of the appended
claims. The scope of the invention(s) should, therefore, be
determined not with reference to the above description, but instead
should be determined with reference to the appended claims along
with their full scope of equivalents. Furthermore, it should be
understood that the appended claims do not necessarily comprise the
broadest scope of the invention(s) which the applicant is entitled
to claim, or the only manner(s) in which the invention(s) may be
claimed, or that all recited features are necessary.
LISTING OF REFERENCE CHARACTERS
[0082] 100 firearm [0083] 110 lower receiver [0084] 120 upper
receiver [0085] 130 barrel [0086] 132 barrel bore [0087] 133 barrel
wall [0088] 134 barrel distal end stepped portion [0089] 135 barrel
narrow (neck) portion [0090] 136 barrel shoulder [0091] 137 barrel
terminal (muzzle) end [0092] 138 barrel external (male) threads
[0093] 139 barrel semi-circular recess [0094] 140 muzzle device
[0095] 141 body [0096] 142 main body [0097] 144 barrel mounting
portion [0098] 145 combustion gas receiving portion shoulder [0099]
146 barrel mounting portion bore (counter-bore) [0100] 147 barrel
mounting portion sidewall [0101] 148 barrel mounting portion
counter-bore narrow portion [0102] 150 barrel mounting portion
counter-bore (female) threads [0103] 152 barrel retaining pin
[0104] 154 barrel mounting portion semi-circular recess [0105] 156
combustion gas receiving portion [0106] 157 enlarged combustion gas
(burn) chamber [0107] 158 cavity of main body [0108] 159 combustion
gas outlet port [0109] 160 main body sidewall [0110] 161 rear wall
of combustion gas burn chamber [0111] 162 main body distal end
[0112] 164 main body distal (female) threads [0113] 166 combustion
gas receiving portion bore [0114] 168 combustion gas receiving
portion counter-bore narrow portion [0115] 170 combustion gas
receiving portion counter-bore wide portion [0116] 172 retaining
pin [0117] 174 through-bore in main body [0118] 180 end cap [0119]
181 end cap sidewall [0120] 182 transverse end wall [0121] 183
outer surface of transverse wall [0122] 184 end cap (male) threads
[0123] 185 inner gas impingement surface of transverse wall [0124]
186 end cap center (projectile) orifice [0125] 188 end cap shoulder
[0126] 189 end cap detents [0127] 190 end cap projections [0128]
192 end cap circular recess [0129] 194 cavity of end cap [0130] 200
end cap retaining pin [0131] 202 head [0132] 204 shaft [0133] 210
spring [0134] 220 combustion gas return tube [0135] 222 combustion
gas return tube bore [0136] 224 combustion gas return tube wall
[0137] 226 combustion gas return tube inlet port [0138] 250
projectile
* * * * *