U.S. patent application number 13/573455 was filed with the patent office on 2014-03-20 for tactical firearm having heat shielding properties and improved gas energized cartridge feeding.
The applicant listed for this patent is Mark C. Larue. Invention is credited to Mark C. Larue.
Application Number | 20140076148 13/573455 |
Document ID | / |
Family ID | 50273097 |
Filed Date | 2014-03-20 |
United States Patent
Application |
20140076148 |
Kind Code |
A1 |
Larue; Mark C. |
March 20, 2014 |
Tactical firearm having heat shielding properties and improved gas
energized cartridge feeding
Abstract
A tactical firearm has an upper receiver defining a handguard
mounting surface oriented in substantially normal relation with the
bore of a rifle barrel and defining handguard mounting flanges that
project radially from the upper receiver. A handguard is provided
with like radiating handguard mounting flanges and is releasably
secured to the upper receiver by fasteners. A barrel extends
through the handguard and is secured by a barrel retainer to the
upper receiver in a manner achieving clearance and thermal
isolation of the handguard from the barrel and barrel retainer.
Inventors: |
Larue; Mark C.; (Leander,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Larue; Mark C. |
Leander |
TX |
US |
|
|
Family ID: |
50273097 |
Appl. No.: |
13/573455 |
Filed: |
September 14, 2012 |
Current U.S.
Class: |
89/191.01 ;
42/16 |
Current CPC
Class: |
F41C 23/16 20130101;
F41A 3/12 20130101; F41G 1/00 20130101; F41C 27/00 20130101; F41A
5/18 20130101; F41A 3/64 20130101 |
Class at
Publication: |
89/191.01 ;
42/16 |
International
Class: |
F41C 27/00 20060101
F41C027/00; F41G 1/00 20060101 F41G001/00; F41A 5/18 20060101
F41A005/18; F41A 3/12 20060101 F41A003/12; F41C 23/16 20060101
F41C023/16 |
Claims
1. A tactical firearm, comprising: a receiver member defining a
first mounting flange and having a first rail mounting surface; a
handguard member defining a second mounting flange being secured in
face to face relation with said first mounting flange; and flange
fastener members securing said first and second mounting flanges in
releasable fixed relation with one another.
2. The tactical firearm of claim 1, comprising: said receiver
member defining a first rail mounting surface and said handguard
member defining a second rail mounting surface being disposed in
co-planar relation with said first rail mounting surface; a
one-piece elongate sight mounting rail extending substantially
along the combined length of said receiver member and said
handguard member and defining a mounting surface having face to
face relation with said first and second rail mounting surfaces,
said one-piece elongate sight mounting rail having a
cross-sectional mount geometry for receiving clamp type sight mount
devices in releasable clamped relation therewith; and rail fastener
members securing said one-piece elongate sight mounting rail to
said receiver and said handguard.
3. The tactical firearm of claim 2, comprising: said receiver
having a rear end portion and a front end portion; said handguard
having a rear end portion and a front end portion; and said
one-piece elongate sight mounting rail having a rear end located at
said rear portion of said receiver and a front end located at said
front portion of said handguard and being vertically tapered from a
predetermined dimension at said rear end to a dimension less than
said predetermined dimension at said front end thereof.
4. The tactical firearm of claim 1, comprising: a barrel member
extending through said handguard member and being mounted to said
receiver member; a barrel retainer nut being threaded to said
receiver member and securing said barrel member in oriented and
substantially immovable relation with said receiver member; and
said handguard defining an inner surface disposed in spaced
relation with said barrel member and said barrel nut and being
thermally isolated from metal conducted transfer of heat from said
barrel member and said barrel retainer nut to said handguard.
5. The tactical firearm of claim 1, comprising: a one-piece
elongate sight mounting rail being mounted to said receiver and
said handguard and having a length substantially equal to the
combined length of said receiver and said handguard; and said
one-piece elongate sight mounting rail being tapered along a major
portion of the length thereof and defining a predetermined angle of
cant for location of sighting devices at any selected position
along the length thereof.
6. The tactical firearm of claim 5, comprising: said one-piece
elongate sight mounting rail defining a rear portion located at a
rear portion of said receiver and a front portion located at a
front portion of said handguard having a greater vertical thickness
at said rear portion as compared with the vertical thickness at
said front portion thereof.
7. The tactical firearm of claim 5, comprising: said one-piece
elongate sight mounting rail defining a single mechanical sight
mount located at said rear portion thereof, said single mechanical
sight mount having an elevation permitting manual sighting of said
firearm when optical sighting devices have been removed from said
one-piece elongate sight mounting rail.
8. The tactical firearm of claim 5, comprising: said one-piece
elongate sight mounting rail having a plurality of equally spaced
lands and sight positioning grooves located substantially along the
length thereof; and said one-piece elongate sight mounting rail
defining a single mechanical sight mount structure being located at
the rear portion of said one-piece elongate sight mounting rail and
having a sight orienting surface and mechanical sight positioning
groove for attachment of a mechanical sighting device thereon.
9. The tactical firearm of claim 1, comprising: said receiver
member having a bolt chamber located therein; a bolt carrier having
reciprocating movement within said bolt chamber and having a bolt
member located therein; a buttstock being mounted to said receiver
member and having a buffer housing therein defining a buffer stop;
a spring urged buffer member being moveable within said buffer
housing and having reciprocating movement limited by said buffer
stop; and said bolt carrier having a portion thereof located within
said buffer housing and in contact with said buffer member and
having guided relation with said buffer stop and preventing tilting
of said bolt carrier during rearward movement thereof.
10. The tactical firearm of claim 1, comprising: said receiver
member having a bolt chamber located therein; a bolt carrier having
reciprocating cartridge autoloading movement within said bolt
chamber and having a bolt member located therein, said bolt carrier
and bolt member being moved rearwardly within said bolt chamber by
cartridge gas pressure resulting from firing of said tactical
firearm; a buffer housing having a bolt carrier guide member; a
spring urged buffer member having rearward movement within said
buffer housing responsive to rearward movement of said bolt carrier
and having forward movement within said buffer housing by said
spring; and said bolt carrier having a portion thereof in guided
relation with said carrier guide member and being guided during
rearward and forward reciprocating movement of said bolt carrier
and bolt.
11. The tactical firearm of claim 1, comprising: said receiver
member being defined by an upper receiver defining a bolt chamber
and a lower receiver having a buttstock and defining a buffer
housing; a spring urged buffer member being moveable within said
buffer chamber; and a bolt carrier having a bolt member therein and
having a rear end portion thereof in constant engagement with said
buffer member and in anti-tilt guided relation with said buffer
housing, upon rearward movement of said bolt carrier responsive to
cartridge firing said bolt carrier causing rearward cushioning
movement of said spring urged buffer member and being guided by
said buffer housing to prevent tilting thereof during both rearward
cartridge firing movement and forward spring urged movement.
12. A tactical firearm, comprising: a receiver member defining a
first mounting flange and having a first rail mounting surface; a
handguard member defining a second mounting flange and having a
second rail mounting surface disposed in co-planar relation with
said first rail mounting surface, said first and second mounting
flanges being mounted in face to face relation and defining a
firearm unit of rigid and structurally enhanced character; flange
fastener members securing said first and second mounting flanges in
releasable fixed relation with one another; a one-piece elongate
sight mounting rail extending substantially along the combined
length of said receiver member and said handguard member and
defining a substantially planar mounting surface having face to
face relation with said first and second rail mounting surfaces,
said one-piece elongate sight mounting rail having a
cross-sectional mount geometry for receiving clamp type sight mount
devices in releasable clamped relation therewith; and rail fastener
members securing said one-piece elongate sight mounting rail in
fixed relation with said receiver and said handguard and further
enhancing the rigidity and structurally enhanced character of said
firearm unit.
13. The tactical firearm of claim 12, comprising: said receiver
having a rear end portion and a front end portion; said handguard
having a rear end portion and a front end portion; and said
one-piece elongate sight mounting rail having a rear end located at
said rear portion of said receiver and a front end located at said
front portion of said handguard and being vertically tapered from a
predetermined dimension at said rear end to a dimension less than
said predetermined dimension at said front end thereof.
14. The tactical firearm of claim 12, comprising: a barrel member
extending through and in free-floating relation within said
handguard member and having cartridge receiving relation with said
receiver member; a barrel retainer nut being threaded to said
receiver member and securing a rear end portion of said barrel
member in oriented and substantially immovable relation with said
receiver member; and said handguard defining an inner surface
disposed in spaced relation with said barrel member and said barrel
nut and being thermally isolated from metal conducted transfer of
heat from said barrel member and said barrel retainer nut to said
handguard.
15. The tactical firearm of claim 12, comprising: a one-piece
elongate sight mounting rail being mounted to said receiver and
said handguard and having a length substantially equal to the
combined length of said receiver and said handguard; and said
one-piece elongate sight mounting rail defining a rear portion
located at a rear portion of said receiver and a front portion
located at a front portion of said handguard having a greater
vertical thickness at said rear portion as compared with the
vertical thickness at said front portion thereof and being tapered
along the length thereof and defining a predetermined angle of cant
for location of sighting devices at any selected position along the
length thereof
16. The tactical firearm of claim 15, comprising: said one-piece
elongate sight mounting rail defining a single mechanical sight
mount located at said rear portion thereof, said single mechanical
sight mount having an elevation permitting manual sighting of said
firearm when optical sighting devices have been removed from said
one-piece elongate sight mounting rail; a plurality of equally
spaced lands and sight positioning grooves being located
substantially along the length of said one-piece elongate sight
mounting rail having; and a single mechanical sight mount structure
being located at the rear portion of said one-piece elongate sight
mounting rail and having a sight orienting surface and mechanical
sight positioning groove for attachment of a mechanical sighting
device thereon.
17. The tactical firearm of claim 12, comprising: said receiver
member having a bolt chamber located therein; a bolt carrier having
reciprocating movement within said bolt chamber and having a bolt
member located therein; a buttstock being mounted to said receiver
member and having a buffer housing therein defining a buffer stop;
a spring urged buffer member being moveable within said buffer
housing and having reciprocating movement limited by said buffer
stop; and said bolt carrier having a portion thereof located within
said buffer housing and in contact with said buffer member and
having guided relation with said buffer stop and preventing tilting
of said bolt carrier during rearward movement thereof.
18. The tactical firearm of claim 12, comprising: said receiver
member having a bolt chamber located therein; a bolt carrier having
reciprocating autoloading movement within said bolt chamber and
having a bolt member located therein, said bolt carrier and bolt
member being moved rearwardly within said bolt chamber by cartridge
gas pressure resulting from firing of said tactical firearm; a
buffer housing having a bolt carrier guide member; a spring urged
buffer member having rearward movement within said buffer housing
responsive to rearward movement of said bolt carrier and having
forward movement within said buffer housing by said spring; and
said bolt carrier having a portion thereof in guided relation with
said carrier guide member and being guided during rearward and
forward reciprocating movement of said bolt carrier and bolt.
19. The tactical firearm of claim 12, comprising: said receiver
member being defined by an upper receiver defining a bolt chamber
and a lower receiver having a buttstock and defining a buffer
housing; a spring urged, buffer member being moveable within said
buffer chamber; and a bolt carrier having a bolt member therein and
having a rear end portion thereof in constant engagement with said
buffer member and in anti-tilt guided relation with said buffer
housing, upon rearward movement of said bolt carrier responsive to
cartridge firing said bolt carrier causing rearward cushioning
movement of said spring urged buffer member and being guided by
said buffer housing to prevent tilting thereof during both rearward
cartridge firing movement and forward spring urged movement.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to firearms and more
particularly to semi or full automatic tactical firearms such as
rifles. More particularly, the present invention concerns a
tactical rifle that may be provided with semiautomatic and full
automatic cartridge loading, firing and ejecting capability and is
designed specifically for use of a relatively heavy bulleted
cartridge such as the .308 which has a bullet diameter of 7.62 mm.
The present invention also concerns a tactical firearm having heat
shielding properties to minimize the transfer of heat from the
barrel to the handguard such as during sustained rapid fire
activities. Even more specifically the high accuracy tactical
firearm of the present invention is designed with a continuous
mounting rail having a desired angle of taper or cant to receive
pivot actuated locking mounts of the type that is set forth in U.S.
Pat. No. 7,272,904 of Mark C. LaRue and to permit the mounts to be
located virtually anywhere along the length of the continuous
mounting rail.
[0003] 2. Description of the Prior Art
[0004] During prolonged or sustained rapid fire activities the
typically metal handguards of tactical firearms often become heated
to the extent that soldiers or law enforcement personnel or
shooters in competitive matches need to wear gloves or use other
protective devices to provide thermal isolation of the hands from
the excessive heat of the handguard. This excessive heating
condition is exacerbated by the fact that the handguards of most
tactical in use by the U.S. Military and other related services are
composed of a light-weight metal such as an aluminum alloy, which
is an efficient heat conducting material. Typically in military
rifles a barrel nut is employed to secure the barrel of the firearm
to the receiver and the handguard defined a large internal barrel
chamber, within which the barrel is mounted in free floating
relation. The rear end portion of the handguard is retained in
supported assembly with the receiver and is in supported heat
transferring relation with the outer periphery of the barrel nut.
In the event the barrel should become excessively heated, such as
during rapid fire and sustained fire activities, the excessive heat
build-up in the region of the cartridge chamber of the barrel is
typically transferred through the barrel mounting nut to the
handguard. The handguard car rapidly become heated to the extent
that it can burn and cause pain or injury to the bare hands and
arms of a firearm user. It is desirable therefore to provide a
novel tactical firearm incorporating the usual barrel nut for
releasable free floating barrel mounting but providing for thermal
isolation of the handguard from the barrel nut so that heat from
the barrel will not be transferred in any substantial extent to the
handguard by heat transferring direct metal contact of the
handguard with the barrel or barrel support structure.
[0005] For highly accurate shooting activities, such as in the case
of long range marksmanship activities and for tactical sniper
activities, it has been well known for quite some time that well
designed heavier rifle bullets, such as bullets of 7.62 mm and
greater have more consistent accuracy in a wider variety of
shooting conditions. While 6 mm bullets are known to be quite
accurate at short and medium ranges, such as up to 300 meters for
example, they are not typically considered particularly desirable
for precision long range shooting. At greater distances, such as
distances of 600 to 1000 meters or more the trajectory of smaller
diameter bullets tends to become adversely affected by lateral wind
conditions and wind resistance to a greater extent as compared with
larger diameter heavier bullets. During tactical conditions of
firearm use, however, a greater number of the smaller diameter and
lighter weight cartridges can be more efficiently carried by the
average soldier, which provides the advantage of greater firing
rate during tactical operations. It is desirable therefore to
provide a novel tactical firearm that is designed for long range
highly accurate shooting activity such as, when the firearm is
being used during long range match shooting activities or is being
used during sniper activities by military or law enforcement
personnel.
[0006] During the rapid fire use of virtually all firearms
combustion of the propellant of cartridges causes the development
of considerable heat which causes heating of the barrel, especially
in the region of the firing chamber and causes heating of the
receiver to some extent. If the firearm is provided with a heat
conducting handguard, which is typical of tactical firearms, the
handguard can become heated to the extent that it can be painful to
touch or hold it with the hands of the user. This condition is
especially prevalent when a tactical firearm is used during rapid
firing conditions. The M-16 and M-14 tactical rifles employ barrel
nuts that are tightened to secure the barrel in removable relation
with the receiver of the firearm. The metal handguard is typically
a two piece unit that is composed of an aluminum alloy and is
mounted in contact with and thus in heat transferring relation with
the barrel nut. Forwardly of the barrel nut the barrel is for the
most part free floating and it often becomes heated during rapid
fire conditions so that it is too hot to touch. Excessive heat
buildup of the barrel of typical tactical firearms during rapid
fire conditions is directly transferred through the barrel nut to
the handguard and causes excessive heating of the handguard. It is
desirable therefore to provide a tactical firearm employing a
barrel nut to releasably secure a barrel to the receiver and to
provide the firearm with a handguard that is isolated from direct
heat transferring relation with the barrel and barrel nut, thus
permitting a user to easily hold the handguard of the firearm even
during conditions of rapid firing without encountering conditions
of excessive heat.
[0007] Tactical rifles, such as the M-16 and M-14 of the United
States Armed forces, each incorporate a spring loaded bolt that is
moved rearwardly against a spring force acting on the bolt
responsive to rifle firing by cartridge gas pressure that is
communicated to the bolt from the barrel via a barrel port and gas
tube after a bullet moving within the barrel bore has cleared the
barrel port. The rear portion of the bolt is typically unsupported
as the bolt is moved rearwardly to engagement with the buffer
member by the force of cartridge gas pressure. After having
contacted the buffer member the bolt enters the buffer chamber and
causes cushioning movement of a buffer member against the force of
a buffer spring. At times, especially during conditions of rapid
fire, the rear portion of the bolt can become misaligned or tilted
with respect to the opening of the buffer receptacle during its
rearward movement. This misalignment or tilting of the bolt
mechanism can retard bolt movement and/or cause failure of the
cartridge case extractor of the bolt mechanism to properly extract
a spent cartridge case from the firing chamber and eject it from
the ejector opening of the receiver of the firearm. When this
undesired condition occurs the spent cartridge case, being
improperly extracted and ejected, can become jammed or otherwise
interfere with bolt movement as the bolt is subsequently moved
forwardly by the force of the buffer spring. This condition will
cause failure of the bolt mechanism to properly feed a fresh
cartridge from the magazine of the firearm and can require time
consuming manual adjustment of the cartridge feeding mechanism of
the firearm to restore it to proper operating condition. Most
importantly, this cartridge extracting, ejecting and feeding can
jeopardize the safety of personnel if it should occur during
tactical conditions. It is desirable therefore to provide a novel
tactical firearm mechanism incorporating an anti-tilt
characteristic that ensure precise and efficient guiding of the
bolt carrier and bolt mechanism during all stages of its rearward
gas energized movement and its forward spring energized movement
during firearm use to thus ensure efficient cartridge case
auto-ejection and fresh cartridge feeding during all stages of
mechanical activity as the firearm is operated either during
conditions of slow fire or sustained rapid fire.
[0008] M-16 and M-14 tactical rifles and similar rifles, such as
the AR-15 semi-automatic rifle, typically incorporate a handguard
that is secured to the receiver of the firearm by means of a
handguard retainer nut that is typically tightened manually. At
times the handguard retainer nut is locked in place after it has
been tightened. While this manner of receiver/handguard attachment
is typically desirable for lightweight, small bore tactical rifles
and permits disassembly of the handguard from the receiver, even in
field conditions, for a heavier bore and highly accurate long range
rifle, the stability and structural integrity of the mechanism that
joins the handguard to the receiver mechanism is considered
paramount. The accuracy of the rifle can be adversely affected if
the receiver/handguard connection results in a somewhat flexible
assembly. Accordingly, it is considered desirable to provide a
firearm having a connection joint between the receiver and the
handguard that has enhanced structural integrity thus resulting in
a quite rigid firearm structure which materially enhances the
accuracy of the firearm.
[0009] Many tactical rifles are provided with sight mounting rails,
such as the Picatinny rail, for example, with a section of a sight
mounting rail located on the receiver and with another section of
sight mounting rail located on the handguard. Lateral and bottom
mounting rails of similar design are typically mounted on the
handguard so that various accessories, as white or ultraviolet
lights can be mounted to the firearm to aid firearm sighting by the
user during various conditions of light. Since a handguard is
typically mounted to the receiver be means of a handguard retainer
nut and nut locking mechanism, it is not practical to mount
sighting devices on the rail of the handguard since the handguard
is typically a free floating device and its position can vary with
respect to the receiver and barrel of the firearm. Rather, sighting
devices are typically mounted to the rail of the receiver since the
receiver and barrel are secured in immovable assembly. It is
desirable, however, to provide a firearm with a sight mounting rail
system that is arranged to permit location of a sighting device at
any desired location along the combined length of the receiver and
handguard. It is also desirable to provide a sight mounting rail
system that permits two or more sighting devices to be mounted in
series along the combined length of the receiver and handguard and
also permits a mechanical sighting device to be mounted to the rear
portion receiver and to be used for sighting when the optical
sighting devices have been removed from the mounting rail.
SUMMARY OF THE INVENTION
[0010] It is a principal feature of the present invention to
provide a novel tactical firearm having a handguard that is mounted
to the receiver in such manner that the handguard is substantially
isolated from the barrel and barrel retainer nut of the firearm
from the standpoint of thermal conductivity, thus preventing
excessive heating of the handguard even during conditions of
sustained rapid fire so that the firearm can be efficiently
utilized by personnel.
[0011] It is another feature of the present invention to provide a
novel tactical firearm mechanism that permits the barrel of the
firearm to be substantially free floating within and substantially
along the entire length of the handguard and to maintain the
handguard in spaced and thermally isolated relation with the barrel
to protect the user from the excessive heat that typically builds
up during rapid firing conditions.
[0012] It is also a feature of the present invention to provide a
novel tactical firearm mechanism that provides the reciprocating
bolt carrier and bolt of a semi-automatic or full automatic
tactical rifle with efficient guiding during the entirety of its
rearward and forward auto-loading movement, thus preventing
misalignment or tilting of the bolt during its rearward
movement;
[0013] It is another feature of the present invention to provide a
novel auto-loading tactical firearm that ensures proper cartridge
case extraction and ejection during rearward movement of the bolt
carrier and bolt thereof and facilitating efficient cartridge
loading during forward movement and also minimizing the potential
for cartridge mis-feeding.
[0014] It is an even further feature of the present invention to
provide a novel tactical firearm having a handguard and receiver
that are joined in a manner that lends significant structural
integrity and rigidity to the assembly of the receiver and
handguard which contributes significantly to the accuracy of the
firearm.
[0015] It is another feature of the present invention to provide a
novel tactical firearm that is designed with an elongated sight
mounting rail such as a Picatinny rail and wherein the rail extends
substantially the entire length of the combined receiver and
handguard and is provided with a predetermined angle of tilt or
cant to facilitate the mounting of a sight at any selected location
along the length of the mounting rail. The elongate sight mounting
rail is also designed to facilitate the mounting of a conventional
mechanical sighting device, typically referred to as an "iron
sight" for use of the firearm when optical sights are not present
on the sight mounting rail.
[0016] It is another feature of the present invention to provide a
novel tactical firearm having a sight mounting rail system that
permits two or more sighting devices to be mounted in series along
the combined length of the receiver and handguard.
[0017] Briefly, the various objects and features of the present
invention are realized by providing a tactical firearm having a
receiver and handguard that are connected by mounting flanges that
are secured in surface to surface engagement by a plurality of
retainers to provide a receiver and handguard assembly of enhanced
structural integrity. A single upper sight mounting rail having a
length substantially equal to the combined length of the receiver
and handguard of the tactical rifle is fixed to both the receiver
and handguard. The single upper mounting rail further enhances the
structural integrity of the flange connection of the receiver and
handguard and has an angular cant of a desired angle that permits
one or more sighting devices to be mounted at any suitable location
along the length of the single upper mounting rail. A desired
angular cant of 20 minutes of angle has been found desirable for a
tactical rifle representing a preferred embodiment of the present
invention. However, it is to be understood that the present
invention is not intended to, be limited by a cant of 20 minutes of
angle, it being within the spirit and scope of the present
invention to provide the single sight mounting rail with any other
desired angle of cant. The sight mounting rail is provided with a
desired exterior profile, such as the cross-sectional profile of a
Picatinny rail for example, to permit lever actuated can energized
rail clamping mechanisms to be releasably attached thereto so that
sighting devices can be removed and replaced without loss of zero.
A preferred lever actuated cam energized rail clamping mechanism
for this purpose is constructed according to the teachings of U.S.
Pat. No. 7,272,904 of Mark C. LaRue. Additionally, the rear portion
of the single mounting rail defines a rail seat for a rear
mechanical sighting device, typically referred to as an "iron
sight" which is typically adjustable for windage and elevation and
can be used for mechanical sighting when the optical, laser or
other sighting devices have been removed from the mounting
rail.
[0018] Bolt or bolt carrier tilting takes place because the rear
portion of a conventional bolt mechanism is typically unsupported
during its gas energized rearward movement responsive to the sudden
rearward movement that occurs as a cartridge is fired. This tilting
or misalignment causes the bolt mechanism to come into contact with
structure surrounding the inlet opening of a buffer mechanism,
causing jarring or jamming of the bolt mechanism so that the
cartridge case of the cartridge that has been fired will often fail
to be properly extracted and ejected. In response to the force of a
buffer spring that has been loaded during rearward movement of the
bolt mechanism, as the bolt mechanism begins to be moved forwardly
the improperly extracted and ejected cartridge case will often
interfere with the capability of the bolt to remove a fresh
cartridge from the cartridge magazine and charge the fresh
cartridge into the cartridge chamber of the barrel and cause
locking movement of the bolt. This condition typically results in a
jam that prevents further operation of the firearm until the jam
has been cleared.
[0019] According to the principles of the present invention firearm
jamming due to bolt tilting during firing is largely eliminated by
ensuring that the bolt carrier and bolt mechanism are guided and
prevented from becoming, tilted during all phases of bolt and bolt
carrier movement. A buffer housing is located within a portion of
the buttstock of the tactical rifle and contains a tubular buffer
member that is urged forwardly toward a stop member by a buffer
spring. Within the receiver of the firearm is provided a bolt and
bolt carrier assembly that are moved rearwardly by cartridge gas
pressure and are moved forwardly by the force of a compressed
buffer spring. The bolt carrier has a rear end portion that is
positioned in guided relation with a guide member located within
the inlet opening of the buffer housing. When the bolt carrier and
bolt are in closed and locked relation within the receiver the rear
end portion of the bolt carrier member is in engagement with the
guide member. This causes the bolt carrier to be guided during all
phases of its forward and rearward movement by the internal guide
member within the inlet portion of the buffer housing so that the
bolt carrier member cannot become tilted or in any way misaligned
with respect to the inlet opening of the buffer housing. This
anti-tilt bolt guiding structure is a positive co-axial bolt
carrier alignment system that ensures accurate guided positioning
of the bolt assembly at all stages of its travel. The bolt tilt
problem that typically plagues the cartridge case ejection and
cartridge feeding activity of many tactical firearms is overcome by
the alignment and guiding activity of the positive co-axial bolt
carrier alignment system of the tactical firearm of the present
invention. Since no bolt tilting can occur during rearward gas
energized movement of the bolt mechanism the cartridge case
extraction and fresh cartridge feeding activity of the tactical
firearm, the bolt alignment and guiding system ensures against
cartridge jamming that can result from bolt tilting.
[0020] The barrel of the tactical firearm is mounted in immovable
but releasable relation with respect to the receiver by a barrel
nut that is in threaded engagement with a threaded barrel retainer
extension of the receiver. When tightened by a barrel nut wrench
the barrel nut causes forcible engagement of an annular rib or
flange of the barrel with the circular end surface of the barrel
retainer extension. The handguard is composed of a metal such as an
aluminum alloy that is chosed for its light weight characteristics.
Unfortunately this light weight metal is also capable of
efficiently conducting heat. The handguard defines a central
chamber within which the barrel is free floating. The forward end
of the handguard is positioned about and in spaced and thermally
isolating relation with the barrel nut so that the space between
the handguard and the barrel nut prevents rapid transfer of heat
from the barrel through the barrel nut to the handguard. Since the
barrel nut is quickly heated by heat transfer from, the barrel due
to the firing of cartridges within the cartridge chamber of the
barrel, the spaced relation of the handguard about the barrel nut
prevents the handguard from being excessive heat such as would
occur if the handguard were in metal to metal thermal transferring
contact with the barrel. This heat shielding or thermal isolating
feature permits a user of the firearm to efficiently grip the
handguard and handle the firearm, even during conditions of
sustained rapid fire, without experiencing any discomfort that
might otherwise be caused by touching an excessively heated firearm
component.
[0021] The lower receiver portion of the tactical firearm of the
present invention is provided with a magazine receptacle within
which is received a replaceable spring loaded magazine containing a
number of cartridges that are positioned to be individually moved
from the magazine into the cartridge chamber of the barrel as the
bolt mechanism is moved from its rearmost position forwardly by the
force of the buffer spring. Ease of cartridge movement from the
magazine occurs due to the presence of internal guide bosses that
establish minimal metal to metal contact with the case of the
leading cartridge and thus minimize the frictional resistance to
cartridge movement as the moving bolt mechanism is moved forwardly
by the force of the buffer spring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] So that the manner in which the above recited features,
advantages and objects of the present invention are attained and
can be understood in detail, a more particular description of the
invention, briefly summarized above, may be had by reference to the
preferred embodiment thereof which is illustrated in the appended
drawings, which drawings are incorporated as a part hereof.
[0023] It is to be noted however, that the appended drawings
illustrate only a typical embodiment of this invention and are
therefore not to be considered limiting of its scope, for the
invention may admit to other equally effective embodiments.
In the Drawings:
[0024] FIG. 1 is an elevational view showing a tactical firearm
embodying the principles of the present invention;
[0025] FIG. 2 is a top plan view showing the flange mounted upper
receiver and handguard of the firearm of FIG. 1 and further showing
the elongate one-piece sight mounting rail thereof being mounted to
the upper receiver and handguard of the firearm;
[0026] FIG. 3 is a sectional view taken along line 3-3 of FIG. 2
and showing further details of the firearm mechanism of FIGS. 1 and
2;
[0027] FIG. 4 is a side elevation view showing the flange mounted
upper receiver and handguard of the firearm of FIG. 1 and also
showing the relation of the one-piece sight mounting rail to the
upper receiver and handguard;
[0028] FIG. 5 is an isometric illustration showing the mounting
flange of the upper receiver in detail and further showing mounting
of the barrel of the firearm to the upper receiver;
[0029] FIG. 6 is another isometric illustration showing the
mounting flange of the upper receiver from another point of view
and also showing the barrel and barrel mount nut of the
firearm;
[0030] FIG. 7 is a fragmentary sectional view showing the flanged
mounting of the upper receiver and handguard illustrating the
thermal isolation of the handguard from the barrel retainer nut of
the firearm; and
[0031] FIG. 8 is a partial side elevational view showing portions
of the upper receiver, lower receiver and buttstock and
illustrating the bolt anti-tilt mechanism of the firearm.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0032] Referring now to the drawings and first to the elevational
view of FIG. 1, there is shown a tactical firearm generally at 10
embodying the principles of the present invention. The firearm 10,
is preferably in the form of a tactical rifle of relatively heavy
bore, such as being chambered for the 7.62 mm United States
Military cartridge, also referred to as the .308 caliber rifle
cartridge. However, it should be borne in mind that the present
invention is applicable to firearms of both lighter and heavier
bore without departing from the spirit and scope of the invention.
For purposes of simplicity, though the scope of this invention
encompasses a wide range of firearm devices, the invention is
referred to herein as a tactical rifle.
[0033] The tactical rifle 10 incorporates an upper receiver 12 to
which a lower receiver 14 is pivotally mounted by means of a pivot
pin 16 which extends through corresponding pivot openings of the
lower receiver 14 and a pivot opening 18 of a downwardly extending
pivot projection 20 of the upper receiver 12. The pivot pin 16
permits the relative pivotal movement of the upper and lower
receivers so that the breach of the firearm can be exposed for
cleaning, servicing or for field maintenance as needed. The lower
receiver 14 is provided with a handgrip 22, a trigger guard 24 and
a magazine receptacle 26. A cartridge containing magazine 28 is
received by the magazine receptacle and is secured in place by a
magazine catch. The magazine maintains the first of a number of
cartridges in position to be fed from the magazine and into the
firing chamber of the rifle barrel as the bolt mechanism of the
rifle is moved forwardly. The closed and locked position of the
lower receiver with respect to the upper receiver is shown in FIG.
1 and is achieved by a locking pin 30 which is moveable to a
locking position in engagement within the locking opening 32 of a
locking lug 34 that projects downwardly from the rear portion of
the upper receiver 12 as shown in FIG. 2.
[0034] It is desirable from the standpoint of the present invention
to provide the tactical rifle with a receiver and handguard
assembly having considerable structural integrity so that the
handguard and receiver are immovable one relative to the other.
This feature is important to promote the efficient long range
firing characteristics of the rifle and to permit the location of
sighting devices at any selected location along the combined length
of the receiver and handguard. This feature is accomplished by a
first mounting flange 36 which is located at the front end of the
upper receiver 12 and by a second mounting flange 38 that is
provided at the rear end of a handguard member 40. The mounting
flanges 36 and 38 each define planar surfaces such as shown at 42
in FIGS. 5 and 6 which are disposed in surface to surface
engagement when the handguard is secured in tight assembly with the
upper receiver. The second mounting flange 38 of the handguard is
provided with a plurality of internally threaded retainer openings
which are in registry with a like number of retainer openings 44 of
the mounting flange 36 of the upper receiver 12. Fastener members,
such as Allen screws or any other suitable fasteners, are threaded
into place and secure the first and second mounting flanges 36 and
38 in immovable assembly. Alternatively, if desired a plurality of
bolt and nut assemblies may be employed to secure the mounting
flanges to one another. After the mounting flanges have been
secured in this manner the resulting elongated structure of the
upper receiver and handguard constitute an elongated essentially
rigid unitary rifle component having a length that is essentially
defined by the combined length of the upper receiver 12 and
handguard 40.
[0035] As is evident in the sectional view of FIG. 3 and the
elevation view of FIG. 4 the upper receiver 12 defines an upper
generally planar rail mounting surface 46 and the upper portion of
the handguard 40 defines an upper generally planar rail mounting
surface 48. When the handguard is secured to the upper receiver 12
by the flange assembly as discussed above, the substantially planar
surfaces 46 and 48 are disposed in co-planar relation, thus
essentially defining an elongate rail mounting surface having a
length that is substantially equal to the combined length of the
upper receiver and handguard. An elongate one piece sight mounting
rail 50, which may be designed with a cross-sectional geometry in
the form of a conventional Picatinny rail, is secured with its
lower surface 52 in surface to surface supported engagement with an
elongate rail mounting surface 47 that is defined by the co-planar
surfaces 46 and 48 of the receiver and handguard. A plurality of
retainer members 49 such as Allen screws extend through openings of
the elongate one piece sight mounting rail and are threaded into
threaded openings of the upper receiver and handguard. The elongate
one piece sight mounting rail 50 is of sufficient length to extend
substantially the entirety of the flange secured upper receiver 12
and handguard 40 and has sufficient structural integrity to
significantly enhance the structural integrity of the assembled
upper receiver and handguard unit of the tactical rifle. This
feature provides the tactical firearm with considerable strength
and resistance to bending or other mechanical distortion, thus
enhancing the accuracy of the rifle and making it suitable for long
range highly accurate shooting. The elongate one piece sight
mounting rail 50 has a plurality of evenly spaced lands 53 and
sight location grooves 55 along the length thereof, with the sight
location grooves each defining groove bottom surfaces that are
preferably located in a common plane having the taper or cant of
the rail, though the bottom surfaces of the grooves may be
otherwise located without departing from the spirit and scope of
the present invention.
[0036] As is mentioned above, it is desirable to provide for
mounting of one or more sighting devices at any selected location
along the combined length of the upper receiver and handguard. This
feature is accomplished by the one-piece sight mounting rail 50. A
single optical sighting device 54 is shown to be mounted to the
single sight mounting rail by means of lever actuated releasable
clamp mechanisms 56 that are constructed according to the
principles set forth is U.S. Pat. No. 7,272,904 of Mark C. LaRue,
which patent is incorporated herein by reference for all purposes.
It is not intended however to restrict the use of the one-piece
sight mounting rail to sight mounts having releasable lever
actuated clamp mechanisms since any suitable sight mounting devices
may be employed for sight mounting without departing from the
spirit and scope of the present invention. The one-piece sight
mounting rail 50 is gradually tapered from end to end so that the
rear end thereof is of greater thickness dimension as compared with
the thickness dimension of the front end portion. This feature is
evidenced by the relative spacing of front and rear extended
thickness lines shown at t.sub.1 and t.sub.2 in FIG. 3. Though any
desired taper of the one-piece sight mounting rail may be employed,
for purposes of the preferred embodiment of the present invention
the taper or cant that is employed is 20 minutes of angle. Thus,
the one-piece sight mounting rail 50 defines an elongate sight
mounting structure that is inclined at 20 minutes of angle with
respect to the center-line of the bore of the barrel. This feature,
together with the considerable unbroken length of the one-piece
sight mounting rail permits the mounting of optical sighting
devices at any desired location along the combined length of the
upper receiver 12 and handguard 40 of the firearm. A rear portion
of the one-piece sight mounting rail defines a generally planar
surface 45 having a desired elevation for properly positioning a
mechanical sighting device, typically referred to as an "iron
sight" to enable manual sighting of the firearm when the optical,
laser or other sighting devices have been removed from the rail.
The mechanical sight mount surface 45 may have an elevation that is
lower or higher as compared with the elevation of the lands 53 so
that an iron sight mounted thereto will have a proper elevation for
manual sighting with respect to a conventional blade type front
sight (not shown). The mechanical sight mount seat or platform 45
defines sight location key slot 51, shown in FIGS. 2 and 3, within
which the location key of the iron sight mechanism is received. The
mechanical sight mount seat or platform 45 has an elevation that is
substantially equal to the elevation of the positioning groove
bottom surfaces of the elongate sight mounting rail 50. Thus, when
the optical and other sighting devices have been removed from the
sight mounting rail 50 a mechanical or iron sighting device may be
mounted to the mechanical sight mount seat or platform 45 and may
be employed for manual sighting of the firearm.
[0037] As mentioned above, when auto-loading tactical firearms are
used during rapid fire, especially sustained rapid fire the heat
that builds up in the barrel 64, especially in the region of the
cartridge chamber 66 and barrel retainer nut is typically conducted
to the handguard due to the contact of the handguard with the
barrel retainer nut. Especially since the handguard is typically
composed of a lightweight metal such as an, aluminum alloy, the
handguard can rapidly become excessively heated so that it can be
painful to grip with the bare hands of the user. Often times a user
of this type of firearm will wear thermal insulating gloves or use
a thick cloth or some other protective device to ensure that the
user can continue to grip the handguard even when the handguard has
become too hot to manually handle. To overcome this undesirable
condition the rigid connection that is established by the retained
mounting flanges 36 and 38 positions the inside surface 60 of the
handguard in spaced and thermally isolated relation with the outer
periphery 62 of the barrel nut 58 as shown in FIG. 7. The clearance
or annular gap that separates the outer periphery 62 of barrel nut
from the inner surface 60 of the handguard serves as thermal
isolation which minimizes heat transfer to the handguard 40. Thus,
the handguard will be protected from excessive heating so that a
user can comfortably handle the firearm during all conditions of
firing.
[0038] As mentioned above the rear portion of the bolt and bolt
carrier assembly of a tactical rifle is typically unsupported
during its rearward movement against the buffer and buffer spring
that are located in a buffer receptacle within the buttstock of the
firearm. For this reason the bolt carrier can be shifted laterally,
typically downwardly due to its weight, and can become tilted as it
proceeds rearwardly in response to the gas pressure of cartridge
firing. When bolt carrier tilting occurs, the rear end portion of
the bolt carrier can contact the buttstock structure or a buffer
retainer, thus at least partially stalling the rearward movement of
the bolt carrier and preventing it from smoothly entering into the
buffer chamber and displacing the buffer member against the force
of the buffer spring. This bolt carrier tilting condition often
causes failure of the extractor of the bolt mechanism to move a
cartridge case rearwardly until it engages the ejector and is
ejected laterally from the ejection opening of the upper receiver.
When this bolt carrier tilting condition occurs an empty cartridge
case can remain within the cartridge chamber of the barrel or it
can be only partially extracted from the cartridge chamber. The
cartridge case can be improperly positioned within the receiver so
that it fouls the bolt and, bolt carrier assembly and causes a jam,
thus preventing the proper feeding of a fresh cartridge from the
magazine by the buffer spring energized forwardly moving bolt
mechanism. This undesirable bolt tilting condition is overcome
according to the principles of the present invention by ensuring
that the rear portion of the bolt carrier is positively guided
during all phases of its rearward recoil movement and its forward
cartridge charging movement.
[0039] A buttstock 66 is mounted to the lower receiver 14 as shown
in FIG. 8 and has a buffer tube 68 located therein. A tubular
buffer member 70 is movable within the buffer tube and is urged
forwardly by a buffer spring 72. The buffer member 70 defines a
substantially planar forward end surface or face 74 that is
positioned for engagement by the rear end portion of a bolt
carrier, member 76 having a bolt carrier 76 and a bolt member 77
that is moved rearwardly within the upper receiver 12 responsive to
the energy of cartridge gas pressure. Cartridge gas pressure is
supplied to a bolt actuator mechanism 78 having driving relation
with the bolt mechanism by a gas tube 80 that is in communication
with a barrel port via a barrel port block 82. The barrel port
block 82 is positioned within the forward portion of the handguard
as shown in FIG. 3. The barrel port block 82 may permit cartridge
gas pressure communication with the gas tube 80 via a single port
of the barrel. Preferably, however, the barrel port block is
selector controlled and is capable of permitting selective
communication of a single barrel port or two or more barrel ports
with the gas tube according to the features set forth in U.S.
Provisional Patent Application No. 61/279,817, filed on Oct. 26,
2009 by Mark C. LaRue.
[0040] The rear end portion of the bolt carrier member 76 is
supported and guided by an annular guide surface 84 and is thus
prevented from becoming tilted as the bolt is driven rearwardly in
response to the firing of a cartridge. When the bolt carrier member
76 is at its forward most location within the upper receiver 12 the
rear end portion of the bolt mechanism is located within the
annular guide surface 84 and is in engagement with the planar front
end surface 74 of the buffer member 70. The rear end portion of the
bolt carrier member 76, when the bolt mechanism is closed and
locked, is positioned in guided relation with the internal guide
surface 84 and causes slight compression of the buffer spring 72.
Thus, when a cartridge is fired and gas pressure actuates the bolt
carrier and bolt mechanism rearwardly, the bolt carrier member is
positioned and guided at all times by the internal guide surface.
The rear end portion of the bolt carrier member is positively
oriented and guided at all times and cannot be tilted laterally as
the result of the sudden application of rearward force that is
applied thereto when a cartridge is fired. The bolt carrier member
76 can only move linearly as it is forced into the buffer chamber
and displaces the buffer member against the force of the buffer
spring. The bolt mechanism, therefore, is properly positioned at
all times by this anti-tilt control and thus cannot become tilted
during its rearward movement. The cartridge case extractor of the
bolt member 77 will remain properly positioned at all times to
efficiently extract the cartridge case of a fired cartridge and the
ejector of the bolt assembly will cause ejection of the spent
cartridge case from the ejection opening 86 of the upper receiver
12.
[0041] In view of the foregoing it is evident that the present
invention is one well adapted to attain all of the objects and
features hereinabove set forth, together with other objects and
features which are inherent in the apparatus disclosed herein.
[0042] As will be readily apparent to those skilled in the art, the
present invention may easily be produced in other specific forms
without departing from its spirit or essential characteristics. The
present embodiment is, therefore, to be considered as merely
illustrative and not restrictive, the scope of the invention being
indicated by the claims rather than the foregoing description, and
all changes which come within the meaning and range of equivalence
of the claims are therefore intended to be embraced therein.
* * * * *