U.S. patent application number 13/738023 was filed with the patent office on 2014-03-20 for firearm.
This patent application is currently assigned to Rock River Arms, Inc.. The applicant listed for this patent is Rock River Arms, Inc.. Invention is credited to Lester Larson, JR., Mark Larson.
Application Number | 20140075814 13/738023 |
Document ID | / |
Family ID | 50192660 |
Filed Date | 2014-03-20 |
United States Patent
Application |
20140075814 |
Kind Code |
A1 |
Larson; Mark ; et
al. |
March 20, 2014 |
Firearm
Abstract
A firearm having a gas piston system includes a bolt carrier, an
adjustable gas piston block located forward on the firearm and an
over-the-barrel spring and guide rod arrangement, all of which is
housed and contained in a top rail that runs the length of the
firearm and that maintains the alignment of these firearm
components. The firearm further includes components that provide
full auto firing capability. These components include a specially
designed auto bracket that cooperates with a modified bolt carrier
and a modified upper receiver.
Inventors: |
Larson; Mark; (Colona,
IL) ; Larson, JR.; Lester; (Colona, IL) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Rock River Arms, Inc.; |
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|
US |
|
|
Assignee: |
Rock River Arms, Inc.
Colona
IL
|
Family ID: |
50192660 |
Appl. No.: |
13/738023 |
Filed: |
January 10, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13102331 |
May 6, 2011 |
8468929 |
|
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13738023 |
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61585962 |
Jan 12, 2012 |
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Current U.S.
Class: |
42/72 ; 89/132;
89/193 |
Current CPC
Class: |
F41A 21/00 20130101;
F41A 21/34 20130101; F41A 35/06 20130101; F41C 23/16 20130101; F41A
3/66 20130101; F41A 19/12 20130101; F41A 5/28 20130101; F41G 11/003
20130101; F41A 5/18 20130101; F41A 3/26 20130101; F41C 23/04
20130101; F41A 19/10 20130101; F41A 19/14 20130101 |
Class at
Publication: |
42/72 ; 89/193;
89/132 |
International
Class: |
F41A 5/28 20060101
F41A005/28; F41A 3/66 20060101 F41A003/66; F41C 23/16 20060101
F41C023/16 |
Claims
1. A firearm comprising: a lower receiver, an upper receiver
mounted to the lower receiver, a barrel mounted to the upper
receiver, a handguard surrounding at least part of the barrel, an
elongated mounting rail positioned above the upper receiver, a gas
piston housing mounted to the elongated rail and positioned forward
of the upper receiver, a piston and rod assembly operatively
mounted to the gas piston housing and above the barrel, the piston
and rod assembly operatively connected to a bolt carrier disposed
in the upper receiver, a trigger assembly, the trigger assembly
including a trigger and a hammer, an auto sear, wherein the auto
sear operatively contacts the hammer, and an auto bracket slidably
mounted to the upper receiver and to the bolt carrier, the auto
bracket defining opposing rails connected by a transversely
extending support bracket and an opening in the support bracket for
receiving and contacting the auto sear.
2. The firearm of claim 1, further comprising an adjustable gas
regulator mounted to the gas piston housing.
3. The firearm of claim 2, further comprising a gas plug screw
mounted to the gas piston housing.
4. (canceled)
5. The firearm of claim 1, wherein the rails include opposing
guides extending outwardly from the rails.
6. The firearm of claim 5, wherein the upper receiver defines at
least one elongated groove for receiving at least one of the
guides.
7. The firearm of claim 5, wherein the bolt carrier defines at
least one elongated slot for receiving at least one of the
guides.
8. The firearm of claim 1, wherein the auto bracket defines a pair
of rails joined by a transversely extending bracket, a first pair
of guides extending from the rails, and a second pair of guides
extending from the rails.
9. The firearm of claim 8, wherein the first pair of guides
slidably engages the upper receiver and the second pair of guides
slidably engages the bolt carrier.
10. The firearm of claim 8, wherein the second pair of guides
defines an end stop.
11. The firearm of claim 1, further comprising a guide rod base
mounted to an end of the rod.
12. The firearm of claim 1, further comprising a flash hider
mounted to an end of the barrel.
13. The firearm of claim 8, further comprising a pistol grip
mounted to the lower receiver.
14. The firearm of claim 1, wherein the mounting rail is configured
to mount firearm accessories, including lights and optics.
15. The firearm of claim 1, further comprising a charging handle
that includes foldable ears.
16. The firearm of claim 15, wherein the charging handle is
non-reciprocating.
17. The firearm of claim 2, wherein the auto bracket defines a pair
of rails joined by a bracket, a first pair of guides extending from
the rails for mounting to the upper receiver, and a second pair of
guides extending from the rails for mounting to the bolt
carrier.
18. A firearm comprising: a lower receiver, an upper receiver
mounted to the lower receiver, a barrel mounted to the upper
receiver, a handguard surrounding at least part of the barrel, an
elongated mounting rail positioned above the upper receiver, a
trigger assembly, the trigger assembly including a trigger and a
hammer, an auto sear, wherein the auto sear operatively contacts
the hammer, and an auto bracket slidably mounted to the upper
receiver and to a bolt carrier, the auto bracket defining opposing
rails connected by a transversely extending support bracket and an
opening in the support bracket for receiving and contacting the
auto sear.
19. The firearm of claim 18, wherein the rails include a plurality
of guides extending outwardly from the rails.
20. The firearm of claim 19, wherein the upper receiver defines at
least one elongated groove for receiving at least one of the
guides.
21. The firearm of claim 20, wherein the bolt carrier defines at
least one elongated slot for receiving at least one of the
guides.
22. The firearm of claim 18, wherein the rails include a first pair
of guides extending from the rails, and a second pair of guides
extending from the rails.
23. The firearm of claim 22, wherein the first pair of guides
slidably engages the upper receiver and the second pair of guides
slidably engages the bolt carrier.
24. A firearm comprising: a lower receiver, an upper receiver
mounted to the lower receiver, a barrel mounted to the upper
receiver, a handguard surrounding at least part of the barrel, an
elongated mounting rail positioned above the upper receiver, a
trigger assembly, the trigger assembly including a trigger and a
hammer, an auto sear, wherein the auto sear operatively contacts
the hammer, and an auto bracket slidably mounted to the upper
receiver and to a bolt carrier, the auto bracket defining a pair of
rails joined by a transversely extending support bracket, a first
pair of guides extending from the rails, and a second pair of
guides extending from the rails, and the auto bracket for receiving
and contacting the auto sear.
25. The firearm of claim 24, wherein the first pair of guides
slidably engages the upper receiver and the second pair of guides
slidably engages the bolt carrier.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 13/102,331, filed May 6, 2011. This
application also claims benefit to U.S. Provisional Application No.
61/585,962, filed Jan. 12, 2012. All of these applications are
incorporated herein by reference.
FIELD
[0002] The present invention relates generally to firearms and more
particularly to an improved firearm that utilizes a full auto
firing system that may be incorporated with a direct or indirect
gas impingement system.
BACKGROUND
[0003] Firearms having a direct gas impingement system or an
indirect gas impingement system are known. Direct gas impingement
is a type of gas operation for a firearm that directs gas from a
fired cartridge directly to the bolt carrier or slide assembly to
cycle the action in the firearm.
[0004] More specifically, in a direct gas impingement system, when
the firearm is fired, the exhaust propellant gases from the fired
cartridge are directed through a port at the end of the barrel and
then channeled back to the bolt carrier and will strike, or
impinge, the bolt carrier moving it rearward toward the buttstock
and into a retracted position. The exhaust gases will then
discharge out the ejection port on the side of the firearm near the
buttstock. After discharge, the spring acting on the bolt carrier
will move the bolt carrier back to the engaged position at the same
time causing the bolt to pick up another cartridge from the
magazine and move that cartridge into a battery position within the
firearm's breech.
[0005] There are several known disadvantages with a direct gas
impingement system. As an example, one disadvantage is that the
breech of the firearm becomes fouled more quickly. This is caused
by solids and impurities from the high-temperature gas from the
fired cartridge condensing as they cool and being deposited on the
bolt face and primary operating mechanism. Thorough and frequent
cleaning is required to ensure reliability and proper operation of
the firearm's operating mechanism. The amount of fouling depends
upon the firearm's design as well as the type of propellant powder
used in the fired cartridge. A further disadvantage is that
combustion gases from the fired cartridge heat the bolt and bolt
carrier as the firearm operates. This heating may alter the temper
of metal parts, accelerating wear and decreasing the service life
of the bolt, extractor, and extractor spring. Additionally, heat
dries up the firearm's lubricant and makes the firearm's operating
parts difficult to handle when clearing malfunctions. Heat can also
melt the lacquer coatings of steel cartridge cases, gumming up
parts. Moreover, thermal expansion in the firearm's action can
result in loss of tolerances and consequent degradation in the
firearm's accuracy.
[0006] Firearms having an indirect gas impingement system differ
from the direct gas impingement system in that the exhaust gases do
not directly act on the bolt carrier. Rather, the exhaust gases,
after the firearm has been fired, act on and move a piston-type rod
that, in turn, is operatively connected to the bolt carrier. The
movement of the piston-type rod moves the bolt carrier rearward, or
in the direction opposite to the fired bullet, and to a retracted
position. Once the piston has traveled a certain distance, the
remaining unused gas acting on the piston-type rod is discharged
through a port on the firearm. A spring acting on the piston will
then move the rod and accompanying bolt and bolt carrier forward,
picking up a new cartridge, and moving that cartridge into the
battery position.
[0007] It is also known that a firearm may be modified to provide
full auto firing capability. To accomplish this, it is known to use
a drop-in auto sear. When used, and when the operator pulls the
trigger, the drop-in auto sear intercepts the hammer before the
disconnector intercepts the hammer (i.e., bypasses the
disconnector). The auto sear holds the hammer and functions like
the disconnector until the bolt and bolt carrier move forward into
the battery position. Typically, the bottom rear portion of the
bolt carrier that extends down contacts the auto-sear which
releases the hammer. The bolt and bolt carrier are fully back into
battery position just before the hammer hits the firing pin, which
causes the firearm to discharge a round. The cycle continues until
the operator releases the trigger.
[0008] More specifically, in a normal, semi-automatic operation,
the trigger's front acts as the sear. When the hammer is cocked
there is a mating notch in the hammer that mates to the trigger's
sear surface and they lock together. When the trigger is pulled the
sear surface is rotated out of engagement with the hammer and
spring tension causes the hammer to rotate and hit the firing pin
which in turn strikes the cartridge. Some of the exhaust gasses
discharged from firing are routed back through the firearm and push
the bolt and bolt carrier backwards and consequently push the
hammer down as the bolt and bolt carrier travel rearwards. This
happens quickly so the trigger is still depressed at this time. As
the hammer attempts to rotate back towards the bolt carrier as it
closes, the disconnector catches the hammer to stop the hammer from
rotating. As the trigger is released the disconnector disengages
from the hammer which resets back onto the trigger. This completes
the full cycle operation in semi-automatic mode.
[0009] In a full-automatic operation where an auto-sear is used in
the firearm, the operator rotates the safety selector to full-auto
mode which allows the trigger to move but not the disconnector. The
same operation as stated above happens except at the point where
the disconnector would normally catch the hammer. At this point the
selector is depressing the tail of the disconnector so the
disconnector is rotated out of the way. The result is the hammer
continues rotating until it hits the auto-sear, which is normally
out of the way because the carrier is pushing it rearwardly. The
auto-sear then catches the hammer and restricts its movement. Then,
as the bolt carrier returns and moves forward to the battery
position to pick up another cartridge, the bolt carrier contacts
the auto-sear's tail which rotates it out of the way, which thereby
moves the auto-sear out of contact with the hammer. The hammer is
then allowed to rotate and fire the firearm again. This operation
cycle continues until the trigger is released and the trigger's
sear surface catches the mating notch in the hammer.
SUMMARY
[0010] In an aspect of the present invention, a firearm having a
gas piston system includes a bolt carrier, an adjustable gas piston
block located forward on the firearm and an over-the-barrel spring
and guide rod arrangement, all of which is housed in a top rail
that runs the length of the firearm and that maintains the
alignment of these firearm components. The firearm also includes an
ambidextrous, non-reciprocating charging handle located forward on
the firearm and positioned within the top rail for charging the
firearm. With the present invention, no buffer assembly is
required, allowing for the mounting on the firearm of a
side-folding stock of many different configurations. The invention
improves upon the known indirect impingement systems in a number of
ways, as explained below and illustrated in the drawings.
[0011] In another aspect of the invention, the firearm may include
full auto firing capability. In this embodiment, the firearm may be
equipped with a specially designed auto bracket, a modified upper
receiver, and a modified bolt carrier that cooperate together to
provide full auto capability. These firearm components may be used
with the gas piston system of the invention, described herein, or
with other firearm styles, including direct gas impingement
systems.
[0012] In one embodiment, the firearm may include a lower receiver,
an upper receiver mounted to the lower receiver, a barrel mounted
to the upper receiver, a handguard surrounding at least part of the
barrel, an elongated mounting rail positioned above the upper
receiver, a gas piston housing mounted to the elongated rail and
positioned forward of the upper receiver, a piston and rod assembly
operatively mounted to the gas piston housing and above the barrel,
the piston and rod assembly operatively connected to a bolt carrier
disposed in the upper receiver, a trigger assembly that includes a
trigger and a hammer, an auto sear that operatively contacts the
hammer, and an auto bracket slidably mounted to the upper receiver
and to the bolt carrier, the auto bracket defining an opening for
receiving the auto sear and causing the firearm to operate in full
auto firing mode.
DESCRIPTION OF DRAWINGS
[0013] The present invention is illustrated by way of example and
not limited in the accompanying figures in which like reference
numerals indicate similar elements and in which:
[0014] FIG. 1 illustrates an isometric view of an exemplary firearm
for use with the teachings of the invention.
[0015] FIG. 2 illustrates a side elevation view of the firearm of
FIG. 1.
[0016] FIG. 3 illustrates another side elevation view of the
firearm of FIG. 1.
[0017] FIG. 4 illustrates an end elevation view of the firearm of
FIG. 1.
[0018] FIG. 5 illustrates another end elevation view of the firearm
of FIG. 1.
[0019] FIG. 6 illustrates a top view of the firearm of FIG. 1.
[0020] FIG. 7 illustrates a bottom view of the firearm of FIG.
1.
[0021] FIG. 8 illustrates an isometric view of an alternative
exemplary firearm for use with the teachings of the invention.
[0022] FIG. 9 illustrates an exploded view of the components of the
firearm of FIG. 1.
[0023] FIG. 10 illustrates an exploded view of an exemplary
foldable stock that may be mounted to the firearm of FIG. 8.
[0024] FIG. 11 illustrates an isometric view of a partial firearm
of FIG. 1 with the top mounting rail removed.
[0025] FIG. 12 illustrates an isometric view of an exemplary auto
bracket that will permit the firearm of FIG. 1 to operate with full
auto firing capability.
[0026] FIG. 13 illustrates another isometric view of the auto
bracket of FIG. 12.
[0027] FIG. 14 illustrates a bottom view of the auto bracket of
FIG. 12.
[0028] FIG. 15 illustrates an isometric view of an exemplary bolt
carrier that may be used with the auto bracket of FIG. 12.
[0029] FIG. 16 illustrates a cut-away view of the exemplary bolt
carrier of FIG. 15 showing the slots formed in the bolt
carrier.
[0030] FIG. 17 illustrates an isometric bottom view of the
exemplary bolt carrier of FIG. 15.
[0031] FIG. 18 illustrates an isometric view of an exemplary upper
receiver that may be used with the auto bracket of FIG. 12.
[0032] FIG. 19 illustrates a cut-away view of the exemplary upper
receiver of FIG. 18 showing the elongated grooves or channels.
[0033] FIG. 20 illustrates a side, partial cross-section view of
the exemplary auto bracket mounted to the upper receiver and bolt
carrier.
[0034] FIG. 21 illustrates a side, partial cross-section view of
the exemplary auto bracket mounted to the upper receiver and bolt
carrier.
[0035] FIG. 22 illustrates a side, partial cross-section view of
the exemplary auto bracket mounted to the upper receiver and bolt
carrier.
[0036] FIG. 23 illustrates a side, partial cross-section view of
the exemplary auto bracket mounted to the upper receiver and bolt
carrier.
[0037] FIG. 24 illustrates a side, partial cross-section view of
the exemplary auto bracket mounted to the upper receiver and bolt
carrier.
[0038] FIG. 25 illustrates an isometric view of an exemplary auto
bracket mounted to the upper receiver and bolt carrier.
DESCRIPTION OF THE EMBODIMENTS
[0039] Referring to the drawings, where like numerals indicate like
elements, the firearm 5 of the invention includes an adjustable
performance gas piston system located forward on the firearm in
front of the handguard and away from the operator, a
purpose-designed bolt carrier, and an over-the-barrel spring and
guide rod arrangement, all of which is housed and held in position
by a top rail that runs the length of the firearm and that
maintains the alignment of these firearm components. A hard polymer
handguard is used to protect the operator's hands during operation
of the firearm.
[0040] With the firearm 5, the traditional direct impingement
system is completely eliminated and the problems associated
therewith. Additionally, the absence of the traditional direct
impingement operating system means that no buffer assembly is
required, allowing for the mounting of a side-folding stock of many
different configurations. For the pistol version of the firearm
this means a clean, pistol-like profile without the naked buffer
tube extending out the back of the pistol. An added benefit of the
invention is that the design of the upper receiver and guide rod
base prevents gas blow-by to the back of the receiver and to the
operator's face.
[0041] The firearm of the invention may be in the form of a pistol,
carbine or a rifle, and the performance piston driven system of the
invention may be incorporated into any of these forms of firearms.
The firearm of the invention will work for various calibers such as
.223, .243, 5.56 mm, 9 mm, .308, .40, and others. The gas piston
system of the invention will work with any standard AR-style
receiver and other firearm platforms.
[0042] Additional aspects of the firearm 5 include a piston system
that will direct the discharged gases in front of the front
handguard system and through a specially designed gas piston
regulator housing block and not to the back of the firearm.
Further, the firearm of the invention uses an ambidextrous,
non-reciprocating charging handle mounted at the forward end of the
firearm and in the top rail, the handle having foldable ears which
may be used singly or in unison to charge the firearm. The
handguard mounting system, as more fully explained below, is more
rigid and easier to change out than traditional handguards and
eliminates the delta or handguard slip ring. The handguard may be
changed out to use a handguard system having one or more mounting
rails.
[0043] The use of the adjustable gas system allows for adjustment
of different ammunition and climate changes. The gas regulator used
with the system may be a two position regulator. The slide-in top
rail extending the length of the firearm serves as a guide to hold
and a means to align the bolt carrier, the piston gas regulator
housing and the piston rod assembly. Additionally, the mounting
rail which not only aligns the various components of the firearm
also may be used to mount lights, lasers, optics and other
accessories. Moreover, the mounting rail is also the guide for the
charge handle which is located at the forward end of the firearm.
The firearm also uses a rear mounting rail that may be mounted on
the rear receiver adapter and that may be used to mount a sling
mount. For the carbine or rifle version of the firearm, a foldable
stock may be mounted to the rear receiver adapter or to the rear of
the receiver. Also, the gas regulator housing may include a
mounting rail on one of its sides to mount a sling mount, weapon
lights or other accessories. These unique aspects, among others, of
the invention are further described below and illustrated in the
drawings.
[0044] Referring to FIGS. 1-9 and 11, FIG. 1 illustrates an
isometric view of pistol version of a firearm 5 of the invention,
and FIGS. 2-7 illustrate various views of the firearm 5 of FIG. 1.
FIG. 8 illustrates a carbine version of the firearm 5 of the
invention. The primary difference between the carbine version and
the pistol version is the length of the barrel, handguard and top
rail. FIG. 9 illustrates an exploded view of the various components
of the firearm 5. FIG. 11 illustrates a partial view of the firearm
5 with the top mounting rail removed.
[0045] As depicted in FIGS. 1-9 and 11, the firearm 5 generally
includes a lower receiver 6, an upper receiver 7 mounted to the
lower receiver, a pistol hand grip 8 mounted to the lower receiver,
a handguard 10 mounted around a barrel 20, a magazine well 14
formed in the lower receiver for receiving a magazine 16 that
contains live rounds or cartridges, not shown. The firearm 5 also
includes a trigger 22 and a trigger guard 21 that is pinned to the
lower receiver and located between the magazine well 14 and the
hand grip 8. In an exemplary embodiment, the trigger may be a
two-stage trigger. As known in the art, the magazine 16 is released
from the magazine well 16 upon pressing the magazine button 88. The
upper receiver defines an ejector port that is covered by an
ejector port flap 23 that is held to the upper receiver though an
ejector flap pin 25 and spring 27.
[0046] Referring to FIGS. 9 and 11, the lower receiver 6 includes a
safety selector 104 for providing a safe and fire mode for the
firearm. The selector may also provide for a semi-automatic mode
and a full-automatic mode. The safety selector is held to the
receiver by a safety detent 86 and safety detent spring 85. The
lower receiver also includes a rebound buffer 107 that is mounted
to the inside end of the receiver through the use of a buffer screw
108. The lower receiver 6 also includes the trigger guard 21 that
is pinned to the receiver through the use of a pin 90. Pivot pin 96
and takedown pin 112 extend through openings in the side of the
lower receiver to mount the lower receiver 6 to the upper receiver
7. Pivot pin spring 97, pivot pin detent 98, takedown pin spring
110 and takedown pin detent 111 may be used to hold the respective
pins 96 and 112 to the lower receiver.
[0047] The lower receiver 6 also includes magazine catch and
release components, including the magazine release button 88,
magazine catch spring 89 and magazine catch 99. The magazine catch
and release components are used to hold the magazine 16 in the
magazine well 14 and to release the magazine from the well upon
pressing the magazine release button 88. Various magazines may be
used with the firearm. Moreover, the lower receiver includes a bolt
catch 103, bolt catch plunger 101, bolt catch spring 100 and bolt
catch roll pin 102. Mounted to the lower receiver is the pistol
grip 8 which is secured to the lower receiver through the use of a
pistol grip screw 82 and washer 83. In an exemplary embodiment, the
pistol grip may be a Hogue rubber pistol grip. Mounted to the back
of the lower receiver is a sling adapter base 176 on which may be
mounted a sling adapter, not shown. The receiver includes the
trigger 22, hammer 51, springs 53 and mounting pins 54 that are
used to fire the firearm.
[0048] The handguard 10 is mounted around the barrel 20 and is
secured via screws 43 to front and rear handguard brackets 45. The
barrel 20 is mounted through openings 47 formed in the brackets 45.
The handguard 10 may be made of a hard polymer and may wrap at
least partially around the barrel and may define a plurality of
ribs 49 which serve as a handgrip to assist the operator in
handling the firearm. Alternatively, the handguard 10 may define
one or more rails that surround the barrel and on which may be
mounted firearm accessories, including lights and optics. Other
handguard configurations are possible with the invention. The
handguard protects the operator's hand from the heat generated from
the barrel after the firearm is fired.
[0049] The barrel 20 is mounted at one end to the upper receiver 7
through the use of a barrel nut 17 which threads onto a threaded
end 57 of the upper receiver. At the other end, the barrel passes
through a gas piston housing 122 and threadably connects to an
optional flash hider 1. A crush washer 2 may be positioned between
the flash hider 1 and the threaded end of the barrel. The barrel 20
may include one or more ports 58 in the barrel wall that permit
discharged gases to escape and pass into the gas piston housing
122.
[0050] The gas piston system of the invention includes the gas
piston housing 122 that defines generally a rectangular
configuration and is slidably mounted to the top rail 52. The gas
piston housing may be slidably mounted at its top wall to the top
rail 52 through a tongue and groove configuration, a dovetail
configuration, or other techniques. Alternatively, the gas piston
housing may be fixedly mounted to the top rail 52 through the use
of fasteners or the like. The gas piston housing 122 defines an
opening 124 for receiving the barrel 20 and for permitting the
barrel to pass therethrough. The gas piston housing 122 also
includes a side opening 126 positioned above the opening 124 for
receiving a gas regulator 118 that may be used to control the
amount of gas passing through the gas piston system. A gas
regulator detent 119, spring 120 and locking pin 121 may be used to
hold the gas regulator 118 within the housing 122. The gas
regulator 118 may be a two position regulator and may be adjusted
manually by turning the regulator within the housing through the
use of a screwdriver or similar tool. The gas regulator is
adjustable so the operator can adjust the gas flow through the gas
piston housing for semi-automatic or full-automatic use and for
various types of ammunition, which have different pressures which
can cause what is known as short stroke or excessive pressure
concerns within the gas piston housing.
[0051] The gas piston housing 122 is configured to receive a piston
11 that is operatively connected to a guide rod 130 to form a
piston-rod assembly. The piston 11 is cylindrical in shape and will
move within the housing 122 when exhaust gases from a fired
cartridge pass through the barrel port 58 into the housing 122 and
act on the head of the piston 11. The piston 11 will in turn drive
the operatively connected rod 130 toward the rear of the firearm. A
piston housing plug screw 12 is positioned at an end of the piston
housing and may be held in position by a roll pin 13. Gas piston
housing screws 123 may be mounted through a side of the piston
housing 122. As shown in FIGS. 2 and 7, the gas piston housing 122
may include one or more rails 127 on one or more sides of the
piston housing on which to mount accessories, such as lights and
optics.
[0052] The guide rod 130 is operatively connected at one end to the
piston 11 and is further connected at the other end to a guide rod
base 132. A guide rod washer 131 and guide rod roll pin 133 may be
used to hold the guide rod base 132 onto the guide rod. A coiled,
action spring 72 is positioned around the guide rod along the
majority of the length of the rod. The spring 72 opposes the forces
exerted by the piston 11 during cycling of the firearm. Operatively
connected to the guide rod base 132 is an operating rod housing 29.
The rod housing 29 defines an elongated tube 129 with a through
passageway 141 that receives the rod 130 and spring 72 and mounts
to the bolt carrier 32 through the use of housing screws 28. The
elongated tub 129 defines an exterior surface that is shaped to
match an interior channel 143 formed in the upper receiver 7. The
elongated tube 129 defines an end 145 that serves as the striking
point for the gas piston 11 during operation of the firearm.
[0053] The upper receiver 7 slidably-mounts to the elongated top
rail 52 that extends the length of the upper receiver and beyond.
The elongated top rail 52 houses and aligns the numerous components
of the firearm, including the gas piston housing 122, the handguard
brackets 45, the bolt carrier housing 32, the operating rod housing
29 and guide rod 130. With this configuration, the primary action
components of the firearm will be more accurately aligned to
improve the performance of the firearm. The rail 52 may define a
top surface that may be used to mount numerous accessories to the
firearm, including lights and optics. Any of the rails used with
the firearm 5 may be tactical rails and may comprise a series of
ridges 161 with a T-shaped cross-section interspersed with flat
spacing slots. Optics, for example, are mounted either by sliding
them on from one end of the rail or the other, by means of a
"rail-grabber" which is clamped to the rail with bolts, thumbscrews
or levers, or onto the slots between the raised sections.
[0054] Slidably mounted to the underside of the rail 52 is a
charging handle assembly 26 that may include a pair of opposing
ears 163 that can be operated by either hand to charge the firearm.
The charging handle assembly will mount to a channel formed in the
underside of the rail and will slide along the underside of the
rail. Unlike traditional charging handles, the charging handle 26
is located forward on the firearm. The opposing ears 163 may be
pinned, through the use of pins 165, and folded against the side of
the firearm when not in use. The opposing ears permit ambidextrous
use of the charging handle. The forward located charging handle 26
is non-reciprocating. The charging handle is not affixed to the
operating rod so the charging handle does not run back and forth
when the firearm cycles. In other words, in the exemplary
embodiment, the charging handle does not serve as a forward assist
to the bolt carrier.
[0055] The firearm 5 also includes the bolt 34 and bolt carrier 32.
The bolt includes an extractor 37, extractor pin 38, extractor
spring 35 and spring insert 36. Also included on the bolt are an
ejector 41, ejector spring 40 and ejector roll pin 39. The bolt
carrier includes a cam pin 31. Positioned within the bolt 34 is a
firing pin 27 that is held in position by a firing pin retaining
pin 30. The bolt carrier is configured to be shorter than a
standard bolt carrier without the forward assist notches. The bolt
carrier may include two dovetail cuts in the top of the bolt
carrier to relieve the stresses off of the key screws so as to
prevent the key screws from shearing off during use. Additionally,
the bolt carrier tail diameter has been increased. By increasing
the bolt carrier tail diameter and installing the dovetail in the
top of the carrier there is a reduced chance of shearing of the key
screws.
[0056] In operation, the operator can handle the firearm 5 by
grasping the handguard 10 in one hand while holding the pistol grip
8 in the other hand. The bolt assembly strips a cartridge from the
magazine and moves the cartridge forward into the barrel as the
bolt assembly moves toward a battery position. Once the bolt
assembly is in the battery position, the operator can activate the
trigger. The trigger releases the cocked hammer and the hammer
strikes the firing pin, as known in the art. The firing pin moves
forward and makes contact with the cartridge. The contact between
the firing pin and the cartridge causes the cartridge to fire and
the resultant explosion forces a bullet out the end of the barrel
along a forward path and in the direction the barrel is pointing.
The resultant explosion also causes the bolt assembly to recoil in
a backward direction opposite of the direction of bullet travel.
This is accomplished through the piston driven system of the
invention which includes the elongated rod that is operatively
connected to the bolt assembly. The exhaust gases from the fired
cartridge travel through an opening in the barrel and into the
piston housing and in contact with the piston head of the
piston-rod assembly, located above the barrel. The piston-rod
assembly will drive the operatively connected bolt assembly in the
direction away from the direction of the fired bullet. The movement
of the bolt assembly in turn allows the spent cartridge to be
ejected. Once the piston has traveled a certain distance, the
remaining unused gases acting on the piston is discharged through
the piston housing. The coiled spring around the piston rod will
oppose the backward travel of the bolt assembly and will move the
rod assembly and bolt assembly forward so that another cartridge
can be stripped from the magazine and the bolt assembly can be
returned to the battery position.
[0057] Referring to FIG. 8, there is depicted an alternative
exemplary firearm 3 that is in the configuration of a carbine. The
firearm 3 includes mostly the same components of firearm 5. The
firearm 3 includes a longer barrel 20, handguard 10 and rail 52. As
depicted in FIG. 10, an optional foldable stock 251 may be mounted
to an end of the lower receiver. The foldable stock may define
numerous configurations and may define means for mounting sling
adapters and other accessories. A hinge assembly 167 may be used to
mount the foldable stock to the lower receiver.
[0058] Referring to FIGS. 12-25, in another aspect of the
invention, the firearm 5 may be modified to provide full automatic
firing capability. In this embodiment, and as shown in the figures,
the firearm 5 may be equipped with an auto bracket 500, a modified
upper receiver 502 and modified bolt carrier 504. These firearm
components may be used with a pistol, carbine or rifle style
firearm and may be used with either a direct or indirect gas
impingement system. Additionally, the embodiment may be used in an
AR-style firearm with a shortened bolt carrier or any other
firearms with shortened systems that utilize over the top recoil
systems. The components of this embodiment may also be used with a
drop-in auto sear.
[0059] Referring to FIGS. 12-14, the auto bracket 500 has the
appearance of a sled and defines a pair of opposing rails 550, 552
that are joined together by a support bracket 540. The support
bracket includes an elongated slot 530 that is configured to
receive an auto sear 580, described below. Extending from the rails
550, 552 are a pair of curve-shaped opposing guides 532, 534 that
extend toward each other, and a pair of opposing guides 542, 544
that extend away from each other and that also have curved ends.
The guides 532, 534, 542, and 544 cooperate with grooves 510 formed
in the upper receiver 502, shown in FIG. 19. The guides, which
define curved guide ends, align and mate the auto bracket 500 with
the upper receiver 502 and permit the auto bracket to slide
relative to the upper receiver, as explained below. The guides 532,
534, 542, 544 may define one or more pairs of guides and may define
numerous configurations that permit the mounting of the auto
bracket to the upper receiver and that permit the slidable movement
of the upper receiver relative to the auto bracket. As used herein,
the term guide or guides is to be understood to mean any extension,
protrusion or portion of the auto bracket that extends therefrom,
or forms a part thereof, and is used to operatively connect the
auto bracket to the upper receiver or bolt carrier.
[0060] The support bracket 540 which extends between the opposing
rails 550, 552 provides structural support to the rails 550, 552.
The elongated slot 530 is formed in the support bracket 540 and
extends in a direction between the rails 550, 552. In other words,
the elongated slot is elongated in a direction transverse to the
longitudinal length of the rails 550, 552. The elongated slot 530
is configured to operatively connect to the auto sear. As depicted,
the rail 550 is configured with the guides 532 and 542, while the
rail 552 is configured with guides 534 and 544.
[0061] The rail 550 defines at one end a stop guide 556 and rail
552 defines at one end a stop guide 558. The stop guides 556 and
558 are configured to operatively engage with and slide along the
slots or grooves 514, 516 formed in the bolt carrier 504. The stop
guides 556 and 558 function to stop the auto bracket relative to
the bolt carrier 504, as explained below.
[0062] As used herein, the term auto bracket is meant to broadly
include any slidable structure defining the exemplary configuration
or other functionally similar configuration, cooperating between
the upper receiver and bolt carrier, and operatively connecting to
an auto sear and/or auto cuts made in the lower receiver, to permit
the firearm to operate in a full auto mode. The auto bracket is
also broadly understood to operate with piston driven systems as
well as direct gas impingement systems.
[0063] Referring to FIGS. 15-17, there is depicted an exemplary
bolt carrier 504 that may be used with the auto bracket 500. As
shown in FIGS. 16-17, the bolt carrier 504 defines elongated slots
514 and 516 formed into opposing sides of the base 518 of the bolt
carrier. The slots define an angle and a longitudinal length that
permit a certain length of travel of the auto bracket 500 relative
to the bolt carrier 504. The guides 556, 558 of the auto bracket
500 operatively engage and slide along the slots 514 and 516 formed
in the bolt carrier. The guides 556, 558 may define other shapes
and configurations that permit the auto bracket 500 to operatively
engage and move relative to the bolt carrier 504.
[0064] Referring to FIGS. 18-19, there is depicted an upper
receiver 502 that may be used with the auto bracket 500. The upper
receiver 502 includes elongated grooves or channels 510 that are
machined on the interior channel 143 of the receiver 502 and
configured to operatively receive the guides 532, 534, 542, 544 of
the auto bracket. As explained above, the guides 532, 534, 542, 544
cooperate with the grooves or channels 510 formed in the upper
receiver 502 to permit the auto bracket to slide along the grooves
510 in the upper receiver. The grooves or channels create a rail or
sliding surface for the auto bracket to permit the auto bracket to
actuate through the upper receiver 502.
[0065] The upper receiver 502 includes a front take-down hole 602
for receiving the pivot pin 96. The upper receiver 502 also
includes a rear take-down hole 604 for receiving the take-down pin
112. The pin 96 and pin 112, once removed, permit the upper
receiver 502 to be removed from the lower receiver, as understood
in the art. The remaining exterior features of the receiver 502 are
similar to the upper receiver 7 described above and will not be
repeated here.
[0066] The auto bracket 500 and bolt carrier 504 are mounted
simultaneously into the upper receiver 502. An auto sear 580 which
is used with the exemplary embodiment is then aligned with the
elongated slot 530 in the auto bracket. The assembly is pinned
together with pivot pin 96 and takedown pin 112, which extend
through holes 602, 604 in the upper receiver and in openings in the
side of the lower receiver to mount the lower receiver to the upper
receiver, as described above.
[0067] Referring to FIG. 20, there is illustrated the auto bracket
500 mounted to the bolt carrier 504 and the upper receiver 502.
FIG. 20 depicts the firearm with the safety selector 104 switched
to full-auto position and ready to pull the trigger 583. The auto
bracket 500 will ride in the upper receiver 502 along the grooves
510 formed in the upper receiver, as explained above.
[0068] Referring to FIG. 21, when the operator pulls the trigger
583, the hammer 51 is released and hits the firing pin 27. The
firing pin, in turn, hits the cartridge causing the round to fire.
The disconnector 585 is held in position by the safety selector
when the selector is switched to the full-auto position.
[0069] Referring to FIG. 22, the discharged gas from the fired
cartridge pushes the bolt carrier group rearward and the bolt
carrier pushes the hammer 51 downward and toward the auto sear
actuation arm 582. When the bolt carrier moves rearward the contact
between the bolt carrier and the auto bracket 500 is gone
temporarily. The auto sear 580 spring takes over and pulls the auto
bracket 500 rearward vis-a-vis the actuator arm 582 which
operatively contacts the bracket 500 through the elongated aperture
530, to reset the auto bracket 500.
[0070] Referring to FIG. 23, the bolt carrier 504 contacts the
hammer 51 pushing it downward. When the bolt carrier begins to move
forward, the hammer 51 moves upward and the hook 590 rests on the
auto sear arm 582. After the bolt carrier rebounds forward to pick
up the next round from the magazine, the bolt carrier catches the
auto bracket end guides 556, 558, in the extended position pulling
the auto bracket 500 forward a sufficient distance to disengage the
auto sear actuation arm 582 from the hammer 51, as shown in FIG. 24
and shown moving the auto sear actuation arm from an angular
position to a vertical or upright position. This action releases
the hammer 51 in a timed manner causing the hammer to contact the
firing pin 27 which in turn fires the next cartridge, thereby
causing the firearm to run in automatic mode. After the first
trigger pull, the auto sear arm 582 becomes the resting point for
the hammer until the operator releases the trigger. This operation
cycle continues until the operator releases the trigger. Once the
trigger is released, the operation cycle described above
resets.
[0071] It is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of the components set forth herein and illustrated in the drawings.
The invention is capable of other embodiments and of being
practiced or being carried out in various ways. Variations and
modifications of the foregoing are within the scope of the present
invention. It should be understood that the invention disclosed and
defined herein extends to all alternative combinations of two or
more of the individual features mentioned or evident from the text
and/or drawings. All of these different combinations constitute
various alternative aspects of the present invention.
* * * * *