U.S. patent application number 14/276782 was filed with the patent office on 2015-06-25 for fixed stock assembly and method for forming the same.
The applicant listed for this patent is Mark Andrew Kupanoff. Invention is credited to Mark Andrew Kupanoff.
Application Number | 20150176944 14/276782 |
Document ID | / |
Family ID | 53399637 |
Filed Date | 2015-06-25 |
United States Patent
Application |
20150176944 |
Kind Code |
A1 |
Kupanoff; Mark Andrew |
June 25, 2015 |
FIXED STOCK ASSEMBLY AND METHOD FOR FORMING THE SAME
Abstract
Fixed stock assemblies and methods for forming fixed stock
assemblies are provided. A fixed stock assembly includes a stock,
or stock body, that has a receiver extension cavity extending
therethrough and at least one stock stabilizing member. When a
conventional carbine/collapsible receiver extension is positioned
within the receiver extension cavity, the stock stabilizing member
is actuated/adjusted/manipulated to extend into the receiver
extension cavity and contact the receiver extension, thus exerting
a force on receiver extension and/or a force on the stock. The
stock stabilizing member may contact a surface of the receiver
extension that is substantially perpendicular to a central axis of
the receiver extension cavity and/or the receiver extension. The
force on the receiver extension is in a direction away from the
lower receiver, and the force on the stock is in a direction
towards the lower receiver.
Inventors: |
Kupanoff; Mark Andrew;
(Scottsdale, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kupanoff; Mark Andrew |
Scottsdale |
AZ |
US |
|
|
Family ID: |
53399637 |
Appl. No.: |
14/276782 |
Filed: |
May 13, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61822653 |
May 13, 2013 |
|
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|
Current U.S.
Class: |
42/73 |
Current CPC
Class: |
F41C 23/14 20130101;
F41C 23/12 20130101 |
International
Class: |
F41C 23/14 20060101
F41C023/14; F41C 23/12 20060101 F41C023/12 |
Claims
1. A fixed stock for Stoner-design rifles, the fixed stock
comprising: a stock body with a receiver extension cavity formed
therein, the receiver extension cavity extending from a receiver
extension opening at the front end of the stock body towards the
back end of the stock body; and at least one stock stabilizing
member coupled to the stock body and movable between a first
position and a second position, wherein when the at least one stock
stabilizing member is in the first position, the stock stabilizing
member does not prevent a carbine receiver extension from being
inserted into and removed from the receiver extension cavity, and
when the stock stabilizing member is in the second position, the
stock stabilizing member prevents the carbine receiver extension
from being inserted into and/or removed from the receiver extension
cavity, wherein when a carbine receiver extension, having a front
end and a back end, is positioned within the receiver extension
cavity and the at least one stock stabilizing member is moved from
the first position into the second position, the stock stabilizing
member exerts a force onto the receiver extension and the stock
body so that when the front end of the receiver extension is
threaded into a lower receiver of a Stoner-design rifle, the front
end of the stock body contacts the lower receiver, and the force
exerted on the receiver extension is in a direction away from the
lower receiver while the force exerted on the stock body is in a
direction towards the lower receiver, causing the stock body to
press against the lower receiver, and wherein when the carbine
receiver extension is positioned within the receiver extension
cavity and the at least one stock stabilizing member is in the
second position, all of the at least one stock stabilizing member
is laterally positioned between the front end of the receiver
extension and the back end of the receiver extension.
2. The fixed stock of claim 1, wherein the carbine receiver
extension has a central axis, and where the force exerted on the
carbine receiver extension is in a direction that is not parallel
to the central axis of the carbine receiver extension.
3. The fixed stock of claim 2, wherein the at least one stock
stabilizing member is coupled to the stock body such that the
magnitude of the force exerted on the carbine receiver is
adjustable.
4. The fixed stock of claim 3, wherein the when the at least one
stock stabilizing member is in the second position, the at least
one stock stabilizing member contacts a surface of the carbine
receiver extension which is substantially perpendicular to the
central axis of the carbine receiver extension.
5. The fixed stock of claim 4, wherein the surface of the carbine
receiver extension which is substantially perpendicular to the
central axis of the carbine receiver extension forms a side of a
position detent on the carbine receiver extension.
6. The fixed stock of claim 5, wherein the at least one stock
stabilizing member is coupled to the stock body such that rotation
of the at least one stock stabilizing member causes the at least
one stock stabilizing member to extend into the receiver extension
cavity.
7. The fixed stock of claim 6, wherein an end of the at least one
stock stabilizing member which contacts the surface of the carbine
receiver extension is rounded or tapered.
8. The fixed stock of claim 6, wherein an end of the at least one
stock stabilizing member which contacts the surface of the carbine
receiver extension is made of nylon.
9. A fixed stock for Stoner-design rifles, the fixed stock
comprising: a stock body with a receiver extension cavity formed
therein, the receiver extension cavity extending from a receiver
extension opening at the front end of the stock body towards the
back end of the stock body; and at least one stock stabilizing
member coupled to the stock body and movable between a first
position and a second position, wherein when the at least one stock
stabilizing member is in the first position, the stock stabilizing
member does not prevent a carbine receiver extension from being
inserted into and removed from the receiver extension cavity, and
when the stock stabilizing member is in the second position, the
stock stabilizing member prevents the carbine receiver extension
from being inserted into and/or removed from the receiver extension
cavity, wherein when a carbine receiver extension, having a front
end and a back end, is positioned within the receiver extension
cavity and the at least one stock stabilizing member is moved from
the first position into the second position, the stock stabilizing
member exerts a force onto the receiver extension and the stock
body so that when the front end of the receiver extension is
threaded into a lower receiver of a Stoner-design rifle, the front
end of the stock body contacts the lower receiver, and the force
exerted on the receiver extension is in a direction away from the
lower receiver while the force exerted on the stock body is in a
direction towards the lower receiver, causing the stock body to
press against the lower receiver, wherein when the carbine receiver
extension is positioned within the receiver extension cavity and
the at least one stock stabilizing member is in the second
position, all of the at least one stock stabilizing member is
laterally positioned between the front end of the receiver
extension and the back end of the receiver extension, and wherein
the at least one stock stabilizing member is coupled to the stock
body such that rotation of the at least one stock stabilizing
member causes the magnitude of the force exerted on the carbine
receiver to be adjusted.
10. The fixed stock of claim 9, wherein the carbine receiver
extension has a central axis, and where the force exerted on the
carbine receiver extension is in a direction that is not parallel
to the central axis of the carbine receiver extension.
11. The fixed stock of claim 9, wherein when the at least one stock
stabilizing member is in the second position, the at least one
stock stabilizing member contacts a surface of the carbine receiver
extension which is substantially perpendicular to the central axis
of the carbine receiver extension.
12. The fixed stock of claim 11, wherein the surface of the carbine
receiver extension which is substantially perpendicular to the
central axis of the carbine receiver extension forms a side of a
position detent on the carbine receiver extension.
13. The fixed stock of claim 9, wherein the at least one stock
stabilizing member is coupled to the stock body such that rotation
of the at least one stock stabilizing member causes the at least
one stock stabilizing member to extend into the receiver extension
cavity.
14. The fixed stock of claim 13, wherein an end of the at least one
stock stabilizing member which contacts the surface of the carbine
receiver extension is rounded or tapered.
15. The fixed stock of claim 14, wherein an end of the at least one
stock stabilizing member which contacts the surface of the carbine
receiver extension is made of nylon.
16. A fixed stock for Stoner-design rifles, the fixed stock
comprising: a stock body with a receiver extension cavity formed
therein, the receiver extension cavity extending from a receiver
extension opening at the front end of the stock body towards the
back end of the stock body; and at least one stock stabilizing
member coupled to the stock body and movable between a first
position and a second position, wherein when the at least one stock
stabilizing member is in the first position, the stock stabilizing
member does not prevent a carbine receiver extension from being
inserted into and removed from the receiver extension cavity, and
when the stock stabilizing member is in the second position, the
stock stabilizing member prevents the carbine receiver extension
from being inserted into and/or removed from the receiver extension
cavity, wherein when a carbine receiver extension, having a front
end and a back end, is positioned within the receiver extension
cavity and the at least one stock stabilizing member is moved from
the first position into the second position, the stock stabilizing
member exerts a force onto a surface of the receiver extension that
is substantially perpendicular to a central axis of the receiver
extension and the stock body so that when the front end of the
receiver extension is threaded into a lower receiver of a
Stoner-design rifle, the front end of the stock body contacts the
lower receiver, and the force exerted on the receiver extension is
in a direction away from the lower receiver while the force exerted
on the stock body is in a direction towards the lower receiver,
causing the stock body to press against the lower receiver, wherein
when the carbine receiver extension is positioned within the
receiver extension cavity and the at least one stock stabilizing
member is in the second position, all of the at least one stock
stabilizing member is laterally positioned between the front end of
the receiver extension and the back end of the receiver extension,
and wherein the at least one stock stabilizing member is coupled to
the stock body such that rotation of the at least one stock
stabilizing member causes the magnitude of the force exerted on the
carbine receiver to be adjusted.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/822,653, filed May 13, 2013, entitled "Fixed
Stock Assembly and Method for Forming the Same," which is
incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to stock assemblies for
firearms. In particular, the present invention relates to fixed
stock assemblies for long guns, such as Stoner-design rifles, and
methods for forming such systems.
BACKGROUND
[0003] Recent years have seen a significant increase in demand for
firearms and firearm-related accessories, for both
civilian/recreational and military uses. This increased demand can
especially be seen with the increased sales of assault rifles and
accessories for use with assault rifles. Some of the most popular
assault rifles, for civilian, law enforcement, and military uses,
are those based on Eugene Stoner's design (e.g., the M-16/AR-15 and
variants thereof, the AR-10 and variants thereof, etc.).
[0004] Most Stoner-design rifles manufactured today are equipped
with a "collapsible" butt stock, or stock, assembly. That is, the
length of the stock assembly is capable of being manually adjusted
(i.e., by hand, without tools). Collapsible stock assemblies
typically include or utilize a "carbine" receiver extension (or
buffer tube) that is fixed to the lower receiver of the rifle using
an end plate, which goes on the back end of the lower receiver of
the rifle, and a castle nut, which tightens the receiver extension
and the end plate to the lower receiver.
[0005] However, for various reasons (e.g., personal preference
and/or jurisdictional regulations), some Stoner-design rifles are
equipped with a "fixed" stock assembly, which is not capable of
being adjusted (at least not manually). One example of a fixed
stock assembly is the type that is typically found on M16A4 rifles
and is often referred to as a "rifle" stock assembly, which
utilizes a "rifle" receiver extension that is considerably longer
than a carbine receiver extension. Although these stocks are
"fixed" in length, some users find them undesirably long, and
although they do not utilize an end plate or castle nut, the rifle
receiver extension still needs to be properly "torqued" (i.e.,
tightened) to the lower receiver. This procedure may be difficult
for many users, as they may not have access to the proper tools,
for example.
[0006] In recent years, several fixed stock assemblies have been
developed which are closer in length to collapsible stock
assemblies (i.e., shorter than rifle stock assemblies). However,
some of these fixed stock assemblies require a unique receiver
extension, while others use a conventional carbine receiver
extension but still require the use of the end plate and/or castle
nut, which, similar to rifle receiver extensions, are difficult for
many users to install properly, as specialized tools are
required.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will hereinafter be described in
conjunction with the appended drawing figures, wherein like
numerals denote like elements, and in which:
[0008] FIG. 1 is a side view of a firearm;
[0009] FIG. 2 is an isometric view of a conventional lower receiver
for a Stoner-design rifle;
[0010] FIG. 3 is a side view of a conventional receiver extension
for a collapsible stock assembly for a Stoner-design rifle;
[0011] FIG. 4 is a bottom view of the receiver extension of FIG.
3;
[0012] FIG. 5 is an end view of the receiver extension taken along
line 5-5 in FIG. 3;
[0013] FIG. 6 is a cross-sectional view of the receiver extension
taken along 6-6 in FIG. 5;
[0014] FIG. 7 is an isometric view of a fixed stock according to
some embodiments of the present invention;
[0015] FIG. 8 is a side view of the fixed stock of FIG. 7;
[0016] FIG. 9 is a plan view of a front end of the fixed stock of
FIG. 8;
[0017] FIG. 10 is a cross-sectional view of the fixed stock taken
along line 10-10 in FIG. 9;
[0018] FIGS. 11-17 are various views of the fixed stock of FIG. 7
illustrating installation on the lower receiver of FIG. 2 and the
receiver extension of FIG. 3;
[0019] FIGS. 18 and 19 are side views of the receiver extension of
FIG. 3 threaded into the lower receiver of FIG. 2;
[0020] FIGS. 20 and 21 are cross-sectional views of a fixed stock
according to other embodiments of the present invention;
[0021] FIG. 22 is an isometric view of a spacer which may be used
in the fixed stock shown in FIGS. 20 and 21; and
[0022] FIG. 23 is a side view of a portion of the fixed stock of
FIGS. 20 and 21 illustrating the use of the spacer of FIG. 22.
DETAILED DESCRIPTION
[0023] The following detailed description is merely exemplary in
nature and is not intended to limit the invention or the
application and uses of the invention. Furthermore, there is no
intention to be bound by any expressed or implied theory presented
in the preceding technical field, background, and brief summary, or
the following detailed description. It should also be noted that
FIGS. 1-23 are merely illustrative and may not be drawn to
scale.
[0024] According to one aspect of the present invention, fixed
stock assemblies for Stoner-design rifles are provided. In some
embodiments, a fixed stock assembly includes a stock, or stock
body, that has a receiver extension cavity extending therethrough
and at least one stock stabilizing member extending into the
receiver extension cavity. When a conventional carbine/collapsible
receiver extension, the front end of which is threaded into a lower
receiver for a Stoner-design rifle, is positioned within the
receiver extension cavity, the at least one stock stabilizing
member is actuated/adjusted/manipulated to extend into the receiver
extension cavity and contact the receiver extension, thus exerting
a force on receiver extension and/or a force on the stock. The at
least one stock stabilizing member may contact a surface of the
receiver extension that is substantially perpendicular to a central
axis of the receiver extension cavity (and/or the receiver
extension). The force on the receiver extension is in a direction
away from the lower receiver, and the force on the stock is in a
direction towards the lower receiver.
[0025] The at least one stock stabilizing member (and/or the
force(s) exerted thereby) may be adjusted such that the receiver
extension and/or the stock are suitably "locked" or "tightened"
into position for use of the stock assembly during use of the
respective firearm. As such, the fixed stock assembly allows for
the use of a conventional carbine receiver extension without
requiring an end plate or castle nut and the tools typically
associated with the installation thereof.
[0026] FIG. 1 illustrates a firearm, more particularly, a
Stoner-design rifle (e.g., an AR-15) 10. Generally, the rifle 10
may be understood to include a lower "half" 12 and an upper half
14. Amongst other components which will be appreciated by those
skilled in the art, the lower half 12 includes a lower receiver 16
and a stock assembly 18, and the upper half 14 includes an upper
receiver 20 and a barrel assembly 22.
[0027] The stock assembly 18 shown in FIG. 1 is an example of a
conventional "collapsible" (or "carbine") stock assembly and
includes a carbine receiver extension 24, an end plate 26, a castle
nut 28, and a collapsible stock (or butt stock) 30. As is commonly
understood, the receiver extension 24 is threaded into the back of
the lower receiver 16 and tightened thereto with the castle nut 28,
with the end plate 26 being between the castle nut 28 and the lower
receiver 16 and having the receiver extension 24 inserted
therethrough.
[0028] FIG. 2 illustrates a conventional lower receiver 16 for a
Stoner-design rifle (e.g., a AR-15) in greater detail. In
particular, FIGS. 2-4 illustrate the lower receiver 16 in a
"stripped" configuration (i.e., just the lower receiver itself,
without any other components installed, such as the pistol grip or
other lower receiver parts). The lower receiver 16 has a front end
32 and a back end 34. At the back end 34, the lower receiver
includes a receiver extension hole 36, which has an inner surface
38 with a series of threads formed thereon (not shown in FIG. 2).
The lower receiver 16 also has a depression 40 formed in the back
end 34 thereof, below the receiver extension hole 36.
[0029] FIGS. 3-6 illustrate the receiver extension 24 in greater
detail. As will be recognized by one skilled in the art, the
receiver extension 24 is a conventional receiver extension for
collapsible/carbine stock assemblies, as produced by various
manufacturers. The receiver extension 24 has a front end 42 and a
back end 44. As shown, the receiver extension 24 has a series of
threads 46 formed on the outer surface near the front end 42. The
receiver extension 24 is substantially hollow and has an opening at
the front end 42. The receiver extension 24 also includes a ridge
structure 48 extending therefrom (i.e., on a side thereof that is
usually considered the bottom or lower side thereof). The forward
portion of the ridge structure 48 has an angled surface 50, while
the rear portion of the ridge structure 48 is flush with the back
end 44 of the receiver extension 24. As shown, the ridge structure
48 also has a depressed channel 52 extending a majority of the
length of the ridge structure 48. A series of stock position
detents (or depressions) 54 are formed within the channel 52. Of
particular interest is that the position detents 54 closest to the
back end 44 and the front end 42 of the receiver extension 24
include elongated vertical surfaces 56 that also correspond to the
respective ends of the depressed channel 52. The receiver extension
24 may be understood to have a central axis 55 extending through a
center of a cavity extending from the opening at the front end 42
to the back end 44. Vertical surfaces 56 may be perpendicular (or
orthogonal), or at least substantially so, to the central axis
55.
[0030] In some embodiments, the receiver extension 24 is a
"mil-spec" receiver extension. Thus, the receiver extension 24 may
have a length 56 of approximately 7.25 inches and a diameter 58 of
approximately 1.185 inches at the front end 40 (i.e., including the
threads 44), but at other portions of the receiver extension (i.e.,
without the threads 46) the diameter 58 may be, for example,
between 1.145 and 1.150 inches (excluding the ridge structure 48).
The ridge structure 48 may have a width 60 of, for example, between
0.485 and 0.495 inches. The receiver extension 24 may have of wall
thickness 62 of approximately 0.73 inches. However, in some
embodiments, the receiver extension 24 may be a "commercial"
receiver extension, which as slightly different, but similar,
dimensions (e.g., a slightly larger diameter at the portions
thereof without the threads 46), as is commonly understood. It
should be understood that the fixed stock assembly described below
may be sized/shaped to accommodate both mil-spec and commercial
receiver extensions, or alternatively, different embodiments of the
stock assembly may be made for mil-spec and commercial receiver
extensions.
[0031] FIGS. 7-10 illustrate a fixed stock 70 according to some
embodiments of the present invention. The fixed stock is
substantially made of a singular, integral piece of material that
forms a stock body with a front end 72, a back end 74, a top side
76, and a bottom side 78. In some embodiments, the stock body is
made of a polymer or plastic material, but other materials, such as
metals (e.g., aluminum) may be used.
[0032] The stock 70 has a substantially elongate shape with a
receiver extension cavity (or channel) 80 extending therethrough
from the front end 72 (i.e., beginning at an opening at the front
end 72) towards the back end 74. In some embodiments, the receiver
extension cavity 80 is shaped to have a lower portion 82 such that
the receiver extension cavity 80 substantially has the same
cross-sectional shape and size as a mil-spec receiver extension (or
in some embodiments, a commercial receiver extension). On the front
end 72 of the stock 70, an alignment protrusion 84 extends outwards
below the opening for the receiver extension cavity 80. In the
example shown, the alignment protrusion 84 has a substantially
semi-circular shape and may have dimensions (e.g., width, length,
depth, etc.) similar to the depression 40 on the back end 34 of the
lower receiver 16 (FIG. 2).
[0033] Still referring to FIGS. 7-10, the stock 70 includes a ridge
86 extending from the bottom side 78 thereof, which connects to the
back end 74 as shown. A series of stock stabilizing member openings
88, 90, and 92 are formed through the bottom side 78 of the stock
70. As shown specifically in FIG. 10, the openings 88, 90, and 92
extend through the stock 70 to the receiver extension cavity 80 (or
the lower portion 82 thereof). In some embodiments, the openings
88, 90, and 92 have circular cross-sections and are arranged in the
stock 70 such that the central axes 94 thereof are at an angle to a
central axis 96 of the receiver extension cavity 80 (and/or of the
stock 70 and/or that of the receiver extension 24). In the example
shown, the angle between the central axes 94 and the central axis
96 of the receiver extension cavity 96 is approximately 45 degrees.
However, in other embodiments, this angle may be any angle between
90 degrees (i.e., perpendicular) and 0 degrees (or essentially
parallel) and may vary between the openings 88, 90, and 92. In some
embodiments, the angle is any angle between 60 degrees and 30
degrees.
[0034] It should noted that the openings 88, 90, and 92 are
arranged such that as they extend away from the receiver extension
cavity 80, the openings 88, 90, and 92 get closer to the front end
72 of the stock (or conversely, as the openings 88, 90, and 92
extend closer to the receiver extension cavity 80, they get closer
to the back end 74 of the stock 70).
[0035] Still referring to FIG. 10, a threaded insert (or helical
insert) 98 is embedded within each of the openings 88, 90, and 92.
The threaded inserts 98 may be made of steel. However, in some
embodiments, rather than inserts made from a material different
than the stock 70, the threads provided by the inserts 98 may
simply be formed in the material of the stock (i.e., the openings
88, 90, and 92 may be "tapped" or otherwise have threads formed
therein).
[0036] FIGS. 11-17 illustrate the installation of the stock 70. As
shown in FIG. 11, the front end 42 of the receiver extension 24 is
first threaded into the receiver extension hole 36 of the lower
receiver 16. As is commonly understood, the receiver extension 24
is threaded into the lower receiver 16 until the front end 42 is
positioned appropriately relative to a buffer detent (not shown) in
the lower receiver 16, with the ridge structure 48 on the receiver
extension 24 being oriented as shown in FIG. 11 (i.e., facing
"down"). It should be noted that in at least some embodiments, the
receiver extension 24 is installed without an end plate or castle
nut (which are typically used when installing conventional receiver
extensions for collapsible/carbine stock assemblies). As such, as
installed in FIG. 11, the receiver extension 24 may exhibit some
"wobble" or "play" (i.e., the receiver extension is somewhat
"loose" after being threaded into the lower receiver 16 without the
end plate and castle nut).
[0037] As shown in FIGS. 12 and 13, the stock 70 is then slid onto
the receiver extension 24 (i.e., the receiver extension 24 fits
into the receiver extension cavity 80). Due to the mating between
receiver extension 24 and the receiver extension cavity 80
(especially because the ridge structure 48 of the receiver
extension 24 fits into the lower portion 82 of the receiver
extension cavity 80 as shown in FIG. 13), the stock 70 is
substantially prevented from rotating relative to the receiver
extension 24. In some embodiments, the receiver extension 24 may
fit very tightly into the receiver extension cavity 80, and may
even require the use of a hammer or similar tool to tap the stock
70 completely into position.
[0038] Referring now to FIGS. 12 and 14, the front end 72 of the
stock 70 is pressed against the back end 34 of the lower receiver
16 such that the alignment protrusion 84 on the front end 72 of the
stock 70 is inserted into the depression 40 on the back end 34 of
the lower receiver 16. Thus, the alignment protrusion 84 mates with
the depression 40 to prevent the stock 70 from rotating relative to
the lower receiver 16, which in turn prevents the receiver
extension 24 from rotating relative to the lower receiver 16 (due
to the mating between the receiver extension 24 and the receiver
extension cavity 80 in stock 70).
[0039] As shown in FIG. 15, after the stock 70 is pressed onto the
receiver extension 24, stock stabilizing members are inserted into
the openings 88, 90, and 92 in the bottom side 78 of the stock 70
(or alternatively, the stock stabilizing members are previously
positioned within the openings 88, 90, and 92). In the example
shown, the stock stabilizing members are fasteners 100. Each of the
fasteners 100 are threaded into/through the respective threaded
insert 98 and into the receiver extension cavity 80 of the stock 70
to press against selected portions of the receiver extension 24 (as
dictated by the positioning and orientation of the openings 88, 90,
and 92 and threaded inserts 98).
[0040] As such, the fasteners 100 (or stock stabilizing members)
may be movable between (at least) two positions. In a first
position, the fasteners 100 do not extend into the receiver
extension cavity 80 such that the receiver extension 24 may be
freely inserted into and removed from the receiver extension cavity
80. In the second position, the fasteners 100 extend into the
receiver extension cavity 80 such that the receiver extension 24 is
prevented from being freely inserted into and removed from the
receiver extension cavity 80. More particularly, when the fasteners
100 are moved/adjusted/manipulated into the second position after
the receiver extension 24 has been inserted into the receiver
extension cavity 80, the fasteners 100 prevent the receiver
extension 24 from coming out of the receiver extension cavity
80.
[0041] In the depicted embodiment, the fasteners 100 are set
screws, but in other embodiments, regular screws or bolts may be
used. Further, in yet further embodiments, the stock stabilizing
members may take for form of knobs or the like such that they may
be manipulated by hand, as opposed to requiring a screw driver,
allen key, or socket head driver.
[0042] In particular, in the depicted embodiment, the fastener 100
inserted into opening 88 presses against the angled surface 50 of
the ridge structure 48 on the receiver extension 24. The fasteners
100 inserted into openings 90 and 92 press against the vertical,
side surfaces of the positions detents 54 of the ridge structure 48
(e.g., surface 56). Thus, in some embodiments, the width or
diameter of the fasteners 100 may be less than a width of the
depressed channel 52. The overall effect of the pressing of the
fasteners 100 against the various portions of the receiver
extension 24 is to apply opposing forces on the receiver extension
24 and the stock 70. In particular, the receiver extension 24 is
pressed (or pulled) away from the lower receiver 16, while the
stock is pressed into the lower receiver 16.
[0043] As the fasteners 100 are tightened and/or pressed into the
receiver extension 24, the force on the receiver extension 24
causes the receiver extension 24 to be "locked" into position, thus
eliminating any play or wobble between the receiver extension 24
and the lower receiver 16, by essentially applying a "pulling"
force on the receiver extension 24 (i.e., pulling the receiver
extension 24 away from the lower receiver 16). As will be
appreciated by one skilled in the art, this "locking" is caused by
friction and/or interference between the threads 46 on the receiver
extension 24 and the threads on the inner surface 38 of the
receiver extension hole 36 in the lower receiver 16. It should be
noted that the fasteners 100 allow the user to "tune" (or adjust)
the amount (or magnitude) of force exerted on the receiver
extension 24 and/or the stock 70 (i.e., the more the fasteners 100
are tightened, the greater the force is). This may be helpful in
compensating for manufacturing tolerances of the receiver extension
24, the lower receiver 16, and/or the stock 70. Additional
stability may be provided by the stock 70 being pressed into the
lower receiver 16 combined with the tight fit of the receiver
extension 24 within the receiver extension cavity 80.
[0044] It should also be noted that, in some embodiments, the force
applied to the receiver extension 24 by at least some of the
fasteners may be in a direction that is substantially directly away
from the lower receiver 16 (and/or substantially parallel to the
central axis 96 of the receiver extension channel 80). However,
because the fasteners 100 are pressing into the receiver extension
24 in a direction that is not perfectly parallel to axis 96 and/or
axis 55, the actual direction in which this force is applied may be
at angle, perhaps a small angle (e.g., less than 15 degrees), to
axis 96 and/or 55. In some embodiments, this angle may be the same
as the angle(s) between the central axes 94 of the openings 88, 90,
and 92 and the central axis 96 of the receiver extension cavity 80
(and/or the central axis 55 of the receiver extension 55), as
described above. As described below, in at least some embodiments,
this may be beneficial.
[0045] Referring now to FIG. 16, the fastener 100 inserted through
opening 92 presses against the elongated vertical surface 56 of the
position detent 54 nearest to the back end 44 of the receiver
extension 24. This vertical surface, along with the other vertical
surfaces (i.e., inner sides) of the position detents 54 provide
surfaces suitable for applying a force to the receiver extension 24
substantially directly (i.e., but perhaps at a slight angle) away
from the lower receiver 16. As also shown in FIG. 16, the fasteners
100 may include particular types of tips/ends 102. In FIG. 16, the
end 102 of the fastener 100 is rounded. However, other types of
ends 102 may be used, such as nylon tips (or tips made of other
pliable materials), tapered ends, or conventionally-shaped (e.g.,
"squared" heads) as is discussed below. It should be noted that
some types of ends (e.g., nylon) may help lock the fasteners 100
into position against the receiver extension 24 and/or minimize any
damage to (e.g., scratching) the receiver extension 24 (i.e., nylon
or rounded ends). In the embodiment shown in FIG. 17 (e.g., the
fastener 100 through hole 90), the fastener 100 has a tapered
tip.
[0046] Referring again to FIG. 15, the lateral positions of the
fasteners 100 relative to the receiver extension 24 should be
noted. More particularly, it should be noted that both ends of each
of the fasteners 100 are laterally positioned between the ends 42
and 44 of the receiver extension 24 (or the ends of the receiver
extension cavity 80) and/or that no portion of any of the fasteners
100 extends beyond the back end 44 (or the front end 42) of the
receiver extension 24 (or the ends of the receiver extension cavity
80). As such, the fasteners 100 allow the overall length of the
stock 70 to remain as short as possible (i.e., given a particular
length receiver extension).
[0047] Thus, the stock assembly (i.e., the receiver extension 24
and the stock 70) may be installed without the need for an end
plate or castle nut, using minimal tools (i.e., the only tool
required may be that used to
rotate/thread/adjust/tighten/manipulate the fasteners 100 through
the threaded inserts 98). More specifically, the stock assembly may
be installed without using any gunsmithing tools, such as a vise
and a special wrench (as is typically needed to properly install
castle nuts), while still utilizing a conventional carbine receiver
extension on a Stoner-design rifle with a conventional lower
receiver. However, in some embodiments, the stock 70 may be
configured to allow for the use of an end plate and/or castle nut
(e.g., such as in the case when those components are already
installed). In such embodiments, a portion of the stock 70 near the
front end 72 may be removable (e.g., a spacer or collar portion) to
provide sufficient room for the end plate and/or castle nut.
[0048] Additionally, because multiple fasteners 100 are used, at
least in some embodiments, to pull the receiver extension 24 away
from the lower receiver 16 and/or push the stock 70 into the lower
receiver 16, the stock assembly described above provides a level of
redundancy not provided by conventional stock assemblies (i.e.,
collapsible or fixed). That is, in the event that one of the
fasteners 100 loosens, or otherwise fails, during use, the
remaining fasteners 100 will continue to hold the receiver
extension 24 and/or the stock 70 in a suitable position (i.e., the
remaining fasteners 100 will continue to exerted the force(s)
described above and hold the receiver extension 24 and the stock 70
firm in place). In contrast, conventional stock assemblies may fail
(i.e., come loose) if the castle nut loosens (in collapsible stock
assemblies) or if the rifle receiver extension loosens from the
lower receiver (in rifle stock assemblies).
[0049] Referring now to FIG. 18, as described above, when the
receiver extension 24 is initially threaded into the receiver
extension hole 36 in the lower receiver 36, the receiver extension
24 may "wobble" relative to the lower receiver, as indicated by the
arrows shown. As shown in FIG. 19, when the stock 70 (not shown) is
installed, and the fasteners 100 are tightened as described above,
the receive extension may "cant" (or tilt) within the receiver
extension hole 36 due to the fact that the force exerted on the
receiver extension 24 may not be in a directly that is perfectly
parallel to the central axis 55 of the receiver extension. This is
evident in FIG. 19 because of the movement of the central axis 55
shown. This canting/tilting of the receiver extension 24 may
actually facilitate the "locking" of the receiver extension 24
relative to the lower receiver 16. More particularly, this
canting/tilting may cause a positive engagement between the threads
46 on the receiver extension 24 and the threads on the inner
surface 38 of the receiver extension hole 36 with a relatively
small force (i.e., at an angle to the central axis 55) being
applied on the receiver extension 24.
[0050] It should be noted that due to the tolerances typically used
when manufacturing receiver extensions 24 and lower receivers 16,
this canting/tilting may be relatively minor (e.g., at most a few
degrees). Thus, this canting/tilting will not adversely effect the
operation of the rifle (e.g., because the bolt carrier of a
Stoner-design rifle only extends into the receiver extension 24 a
few inches during cycling). As such, in at least some embodiments
described herein, this canting/tilting may actually be considered
to be beneficial, as it facilitates the "locking" between the
receiver extension 24 and the lower receiver 16.
[0051] In some embodiments, the stock 70 is sized so that it may be
utilized with different types of collapsible/carbine receiver
extensions. An example of such an embodiment is shown in FIGS. 20
and 21. In FIG. 20, the stock 70 is utilized with a conventional
(e.g., mil-spec) receiver extension 24. However, note that the
receiver extension 24 shown in FIG. 20 has six position detents 54,
as opposed to four (which is the case with the receiver extension
described above). As will be appreciated by one skilled in the art,
true "mil-spec" collapsible/carbine receiver extensions 24 usually
have four position detents 54. However, some collapsible/carbine
receiver extensions 24 have six position detents 54, but are still
regarded as "mil-spec" (i.e., such receiver extensions typically
have the same overall dimensions as true mil-spec receiver
extensions).
[0052] Still referring to FIG. 20, note the gap 104 between the end
44 of the receiver extension 24 and the end of the receiver
extension cavity 80 in the stock 70. Also note in FIG. 20 that the
fastener 100 inserted into opening 88 has a nylon tip, while the
others have tapered ends (i.e., in some embodiments, different
types of fasteners 100 may be used in the openings 88, 90, and
92).
[0053] Referring now to FIG. 21, the stock 70 shown in FIG. 20 is
being utilized with a slightly longer collapsible/carbine receiver
extension 24, as is evident due to the decreased size of gap 104.
An example of such a receiver extension 24 is the A5 receiver
extension for the A5 buffer system/stock assembly available from
Vltor Weapons Systems of Tucson, Ariz. In some embodiments, the
stock 70 is capable of utilizing both conventional
collapsible/carbine receiver extensions and receiver extensions
with different lengths (such as the A5) with no modifications
whatsoever.
[0054] However, optionally, an additional opening 106 (which may
have a threaded structure therein similar to that described above)
is provided in the stock 70 as shown by the dashed lines in FIG.
21. As is evident from the position of opening 106, the opening 106
may be used with the receiver extension 24 shown in FIG. 21 in a
manner similar to that of opening 92 when the receiver extension
shown in FIG. 20 is utilized. As another option, in some
embodiments, a spacer 108 is provided as shown in FIG. 21, which is
shown in greater detail in FIGS. 22 and 23. It should be noted that
both the additional opening 106 and the spacer 108 are not
required, at least in some embodiments, for the stock 70 to
accommodate such different types of collapsible/carbine receiver
extensions.
[0055] Other embodiments may be designed to be compatible with
rifles besides Stoner-design rifles (such as AK-47s and variants
thereof and the SCAR series of rifles available from FNH USA of
Mclean, Va.), which have been modified with a receiver extension
similar to receiver extensions for Stoner-design rifles.
[0056] It should also be understood that other accessories may be
integrated into the fixed stock 70 described above. For example,
the fixed stock 70 may also include one or more mechanisms to
attach a sling to the stock 70, such as slots (for looping a sling
therethrough) and "quick-detach" (QD) sling sockets compatible with
QD sling swivels. Additionally, stock extensions and/or butt (or
recoil) pads may be provided which can be attached to the back side
74 of the stock 70 to alter the overall length of the stock 70
and/or make the stock 70 more comfortable to use. Likewise, a
mechanism may be provided on the stock 70 to effectively make the
stock "adjustable" in length (e.g., a slider mechanism in which a
portion of the stock 70 may be actuated relative to the main body
of the stock 70 to adjust the overall length of the 70). However,
in at least some embodiments, the main body of the stock 70 would
still remain in a fixed position relative to the receiver
extension, in a manner similar to that described above.
[0057] Furthermore, the overall shape of the stock 70 may be
changed to provide a different overall "feel" to the user, such as
providing more or less area on the top side 76 for a "cheek weld,"
as is commonly understood.
[0058] Thus, according to one aspect of the present invention, a
fixed stock for Stoner-design rifles is provided. The fixed stock
includes a stock body with a receiver extension cavity formed
therein. The receiver extension cavity extends from a receiver
extension opening at the front end of the stock body towards the
back end of the stock body. The stock body also includes at least
one stock stabilizing member movable between a first position and a
second position. When the (at least one) stock stabilizing member
is in the first position, the stock stabilizing member does not
prevent a carbine receiver extension from being inserted into and
removed from the receiver extension cavity. When the stock
stabilizing member is in the second position, the stock stabilizing
member prevents the carbine receiver extension from being inserted
into and/or removed from the receiver extension cavity.
[0059] When a carbine receiver extension is positioned within the
receiver extension cavity and the stock stabilizing member is moved
from the first position into the second position, the stock
stabilizing member exerts (or applies) a force onto the receiver
extension and/or the stock body. When a front end of the receiver
extension is threaded into a lower receiver of a Stoner-design
rifle, the front end of the stock body contacts the lower receiver,
and the force exerted on the receiver extension is in a direction
away from the lower receiver while the force exerted on the stock
body is in a direction towards the lower receiver, causing the
stock body to press against the lower receiver.
[0060] In some embodiments, when the receiver extension is
positioned with the receiver extension cavity and the stock
stabilizing member is in the second position, the stock stabilizing
member contacts a surface of the receiver extension that is
substantially perpendicular to a central axis of the receiver
extension cavity (and/or the receiver extension).
[0061] In some embodiments, the stock body includes a plurality of
stock stabilizing members. When the front end of the receiver
extension is threaded into the lower receiver, the receiver
extension is positioned with the receiver extension cavity, and
each of the stock stabilizing members are in the second position,
each of the stock stabilizing members exert a force on the receiver
extension in a direction away from the lower receiver and a force
on the stock body in a direction towards the lower receiver.
[0062] In some embodiments, the stock stabilizing members are
fasteners (e.g., threaded members) inserted through stock
stabilizing member openings extending from a side (e.g., bottom
side) of the stock body into the receiver extension cavity. The
stock body may also include a threaded structure (e.g., a threaded
insert or helical insert) positioned adjacent to each of the stock
stabilizing member openings such that each the fasteners is
threaded through a respective one of the threaded structures.
[0063] In some embodiments, a fixed stock for Stoner-design rifles
is provided. The fixed stock includes a stock body with a receiver
extension cavity formed therein. The receiver extension cavity
extends from a receiver extension opening at the front end of the
stock body towards the back end of the stock body. At least one
stock stabilizing member is coupled to the stock body and movable
between a first position and a second position. When the at least
one stock stabilizing member is in the first position, the stock
stabilizing member does not prevent a carbine receiver extension
from being inserted into and removed from the receiver extension
cavity, and when the stock stabilizing member is in the second
position, the stock stabilizing member prevents the carbine
receiver extension from being inserted into and/or removed from the
receiver extension cavity. When a carbine receiver extension,
having a front end and a back end, is positioned within the
receiver extension cavity and the at least one stock stabilizing
member is moved from the first position into the second position,
the stock stabilizing member exerts a force onto the receiver
extension and the stock body so that when the front end of the
receiver extension is threaded into a lower receiver of a
Stoner-design rifle, the front end of the stock body contacts the
lower receiver, and the force exerted on the receiver extension is
in a direction away from the lower receiver while the force exerted
on the stock body is in a direction towards the lower receiver,
causing the stock body to press against the lower receiver. When
the carbine receiver extension is positioned within the receiver
extension cavity and the at least one stock stabilizing member is
in the second position, all of the at least one stock stabilizing
member is laterally positioned between the front end of the
receiver extension and the back end of the receiver extension.
[0064] While at least one exemplary embodiment has been presented
in the foregoing detailed description, it should be appreciated
that a vast number of variations exist. It should also be
appreciated that the exemplary embodiment or exemplary embodiments
are only examples, and are not intended to limit the scope,
applicability, or configuration of the invention in any way.
Rather, the foregoing detailed description will provide those
skilled in the art with a convenient road map for implementing the
exemplary embodiment or exemplary embodiments. It should be
understood that various changes can be made in the function and
arrangement of elements without departing from the scope of the
invention as set forth in the appended claims and the legal
equivalents thereof.
* * * * *