U.S. patent application number 12/028758 was filed with the patent office on 2010-08-19 for modular gunstock.
This patent application is currently assigned to MAGPUL INDUSTRIES CORP. Invention is credited to Richard M. Fitzpatrick, Michael T. Mayberry, Brian L. Nakayama, Eric S. Nakayama.
Application Number | 20100205846 12/028758 |
Document ID | / |
Family ID | 42341785 |
Filed Date | 2010-08-19 |
United States Patent
Application |
20100205846 |
Kind Code |
A1 |
Fitzpatrick; Richard M. ; et
al. |
August 19, 2010 |
MODULAR GUNSTOCK
Abstract
The present invention is a modular gunstock utilizing a
two-piece mounting structure and a stock module. The structure
comprises a weapon attachment, in the case of an AR15/M16 rifle a
receiver extension tube, and a sleeve slidable over said attachment
and containing mounting structure for the stock module. The
disclosed stock module is adjustable for length and features a
length pre-set system, a latch with independent dual-pawls and an
integrated impact buffer, modular tailpiece, and storage. The
sleeve also features a position selectable fixed cheek plate.
Inventors: |
Fitzpatrick; Richard M.;
(Denver, CO) ; Mayberry; Michael T.; (Denver,
CO) ; Nakayama; Brian L.; (Arvada, CO) ;
Nakayama; Eric S.; (Broomfield, CO) |
Correspondence
Address: |
GEOFFREY E. DOBBIN, PATENT ATTORNEY
4278 SOUTH 6220 WEST
WEST VALLEY CITY
UT
84128-6501
US
|
Assignee: |
MAGPUL INDUSTRIES CORP
Boulder
CO
|
Family ID: |
42341785 |
Appl. No.: |
12/028758 |
Filed: |
February 8, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60889244 |
Feb 9, 2007 |
|
|
|
Current U.S.
Class: |
42/73 ;
42/74 |
Current CPC
Class: |
F41C 23/14 20130101;
F41A 11/02 20130101; F41C 23/22 20130101 |
Class at
Publication: |
42/73 ;
42/74 |
International
Class: |
F41C 23/14 20060101
F41C023/14; F41C 23/06 20060101 F41C023/06 |
Claims
1. A modular gunstock comprising: a. a weapon interface structure
having a cylindrical profile; b. a sleeve module slideable upon the
cylindrical profile, the sleeve module further comprising interface
structure for a stock body; c. structure to fixedly interface the
sleeve module and the interface structure; d. an adjustable for
length stock body with a latching mechanism, the latching mechanism
further comprising two independently operated pawls designed to
interface with the interface structure for the stock body.
2. The modular gunstock of claim 1, the weapon interface structure
being a receiver extension tube.
3. The modular gunstock of claim 2, the structure to fixedly
interface the sleeve module and the interface structure being a
bolt secured end cap keyed into structure on the sleeve and being
secured to the interface structure.
4. The modular gunstock of claim 1, the interface structure for the
stock body being a rail, located on the lower half of the sleeve
module.
5. (canceled)
6. (canceled)
7. (canceled)
8. The modular gunstock of claim 1, the latch further comprising an
impact buffer.
9. (canceled)
10. The modular stock of claim 1, the stock body further comprising
a selectable and replaceable tailpiece.
11. The modular stock of claim 1, the sleeve module further
comprising a cheek plate removable from said sleeve module and
positionable in one of a plurality available selectable positions
relative the sleeve module.
12. A modular gunstock comprising: a. a weapon interface structure
having a cylindrical profile; b. a sleeve module slideable upon the
cylindrical profile, the sleeve module further comprising interface
structure for a stock body; c. structure to fixedly interface the
sleeve module and the interface structure; d. an adjustable for
length stock body with a latching mechanism; and e. a length of
pull pre-set system, the system comprising a plurality of threaded
holes located on an underside of the sleeve module, a stop bolt
capable of threadingly interfacing with any of the holes, a spring
biased lateral latch with an upwards angular block located on an
upper side of the stock body and positioned such that the angular
block will strike the stop bolt if the stock body is extended
relative to the sleeve module to a point determined by the location
of the stop bolt and the latch is in a neutral position, and may be
extended beyond said point of the latch is biased so the angular
block avoids the stop bolt.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority on prior filed U.S.
Provisional Application No. 60/889,244, filed Feb. 9, 2007 and
incorporates the same by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of firearms and
more particularly relates to a gunstock with enhanced modularity
and adjustment functions.
BACKGROUND OF THE INVENTION
[0003] Gunstocks or "buttstocks" as they are commonly known, are
well known in the art of firearms. These devices have been used
with "long arms" as a means for resting and securing the weapon
against the shoulder of the user when firing. Gunstocks have also
been used as a weapon in and of themselves in a melee fight. As
such, gunstocks have been developed along many different shapes and
designs and using various materials to increase durability, reduce
the effects of recoil, or "kick", provide adjustability and
customization, increase shooter accuracy, provide storage for gear,
and other goals too myriad to mention.
[0004] One recent goal, however, is to provide a modular gunstock
such that a single stock, or portion of a stock, may be used as a
platform upon which user customizations may be mounted. However,
previous modular gunstocks present a number of difficulties. The
first of which is that the mounting components for such systems
tends to be bulky, as they contain additional mounting features not
present in other stocks. Second, a structural failure in a mounting
component tends to render the weapon useless until a costly part is
replaced. As such, a new modular gunstock is needed that presents a
lower profile, with a simpler mounting paradigm, and is cost
effective to replace in the event of structural failure.
[0005] The present invention is a modular gunstock that provides a
two-piece mounting platform as a new modular paradigm. The present
invention represents a departure from the prior art in that the
modular gunstock of the present invention allows for a durable
two-piece mounting platform upon which stock options may be
mounted. As a two-piece platform, the design draws upon the
inherent strength of having two or more pieces working on concert,
a layering approach, and also allows for the replacement of one of
such pieces should either fail with lesser cost both to the user
and the manufacturer.
[0006] The present invention is described as a preferred embodiment
with an adjustable for length stock attachment. Particular problems
with such systems include lack of stability, insufficient strength,
and cheek weld disruption where the pieces join.
SUMMARY OF THE INVENTION
[0007] In view of the foregoing disadvantages inherent in the known
types of modular gunstocks, this invention provides a new modular
gunstock utilizing a two-piece mounting platform. As such, the
present invention's general purpose is to provide a new and
improved modular gunstock that is durable, lower cost and achieves
the goal of modular customization with greater efficiency. To these
ends, the modular gunstock comprises a receiver extension tube, or
"buffer tube", upon which a sleeve is slid into place and secured
to the tube by conventional means. The sleeve has on its external
surface mounting hardware for the remainder of the stock, in the
form of a rail. Other hardware is provided to provide interface
with the remainder of the weapon. Since the modular gunstock is
primarily mounted upon a buffer tube, it presents an instant
advantage over prior modular systems and earlier carbine systems as
previous systems had to be "timed" to properly engage the receiver
with their interface when screwed into the receiver. This modular
system required no such estimation. It should be noted that the
gunstock as depicted is for a U.S. standard M-16/AR-15 style rifle.
However, it should be appreciated that other weapon platforms which
use a gunstock will benefit from the present invention and that the
only changes necessary will be in the interface of the stock with
the weapon. As such, such changes should be read into and
considered as a within the scope of this invention.
[0008] Other features of this gunstock, as disclosed in the
preferred embodiment, include an adjustable for length stock with a
quick extension pre-set system and a dual, independent pawl latch.
The adjustable for length stock also features a shock cushion for
the latching mechanism, so as to minimize kick and bludgeon shock
to the latch, a storage compartment, a modular tail-piece and a
customizable fixed cheek piece. It should also be appreciated that
this disclosure is only describing one possible stock module to
interface with the system that is the invention. Other stock types,
including fixed stocks and precision shooting stocks, may be
manufactured for this system and still be considered within the
scope of this invention.
[0009] The more important features of the invention have thus been
outlined in order that the more detailed description that follows
may be better understood and in order that the present contribution
to the art may better be appreciated. Additional features of the
invention will be described hereinafter and will form the subject
matter of the claims that follow.
[0010] Many objects of this invention will appear from the
following description and appended claims, reference being made to
the accompanying drawings forming a part of this specification
wherein like reference characters designate corresponding parts in
the several views.
[0011] Before explaining at least one embodiment of the invention
in detail, it is to be understood that the invention is not limited
in its application to the details of construction and the
arrangements of the components set forth in the following
description or illustrated in the drawings. The invention is
capable of other embodiments and of being practiced and carried out
in various ways. Also it is to be understood that the phraseology
and terminology employed herein are for the purpose of description
and should not be regarded as limiting.
[0012] As such, those skilled in the art will appreciate that the
conception, upon which this disclosure is based, may readily be
utilized as a basis for the designing of other structures, methods
and systems for carrying out the several purposes of the present
invention. It is important, therefore, that the claims be regarded
as including such equivalent constructions insofar as they do not
depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a left plan view of the gunstock using an
adjustable for length stock module.
[0014] FIG. 2 is a cross-sectional view of the stock of FIG. 1.
[0015] FIG. 3 is a perspective view of the gunstock's extension
tube module installed on an AR-15 lower receiver.
[0016] FIG. 4 is a perspective view depicting the gunstock's sleeve
module installed.
[0017] FIG. 5 is a perspective view of the assembled mounting
structure's underside.
[0018] FIG. 6 is a right plan view of the assembled mounting and
the length of pull preset system, taken when the stock (not shown)
is in a collapsed position.
[0019] FIG. 6a is a bottom plan view of the system depicted in FIG.
6.
[0020] FIG. 6b is a sectional view, taken along line B-B of FIG.
6.
[0021] FIG. 6c is a rear plan view of the system depicted in FIG.
6.
[0022] FIG. 7 is a right plan view of the assembled mounting and
the length of pull preset system, taken when the stock (not shown)
is in an extended to the pre-set position.
[0023] FIG. 7a is a bottom plan view of the system depicted in FIG.
7.
[0024] FIG. 7b is a sectional view, taken along line B-B of FIG.
7.
[0025] FIG. 7c is a rear plan view of the system depicted in FIG.
7.
[0026] FIG. 8 is a right plan view of the assembled mounting and
the length of pull preset system, taken when the stock (not shown)
is in an extended to the pre-set position and the release latch is
biased to avoid the pre-set.
[0027] FIG. 8a is a bottom plan view of the system depicted in FIG.
8.
[0028] FIG. 8b is a sectional view, taken along line B-B of FIG.
8.
[0029] FIG. 8c is a rear plan view of the system depicted in FIG.
8.
[0030] FIG. 9 is a right plan view of the assembled mounting and
the length of pull preset system, taken when the stock (not shown)
is in a position between the pre-set and the end stop, maintaining
the latch bias of FIG. 8.
[0031] FIG. 9a is a bottom plan view of the system depicted in FIG.
9.
[0032] FIG. 9b is a sectional view, taken along line B-B of FIG.
9.
[0033] FIG. 9c is a rear plan view of the system depicted in FIG.
9.
[0034] FIG. 10 is a right plan view of the assembled mounting and
the length of pull preset system, taken when the stock (not shown)
is in an extended position to the end stop, maintaining the latch
bias of FIG. 8.
[0035] FIG. 10a is a bottom plan view of the system depicted in
FIG. 10.
[0036] FIG. 10b is a sectional view, taken along line B-B of FIG.
10.
[0037] FIG. 10c is a rear plan view of the system depicted in FIG.
10.
[0038] FIG. 11 is a right plan view of the assembled mounting and
the length of pull preset system, taken when the stock (not shown)
is in an extended position to the end stop, releasing the latch
bias of FIG. 8.
[0039] FIG. 11a is a bottom plan view of the system depicted in
FIG. 11.
[0040] FIG. 11b is a sectional view, taken along line B-B of FIG.
11.
[0041] FIG. 11c is a rear plan view of the system depicted in FIG.
11.
[0042] FIG. 12 is a right plan view of the assembled mounting and
the length of pull preset system, taken when the stock (not shown)
is in an extended position to the end stop, reversing the latch
bias of FIG. 8.
[0043] FIG. 12a is a bottom plan view of the system depicted in
FIG. 12.
[0044] FIG. 12b is a sectional view, taken along line B-B of FIG.
12.
[0045] FIG. 12c is a rear plan view of the system depicted in FIG.
12.
[0046] FIG. 13 is a perspective view of the latch mechanism for the
stock, according to the present invention.
[0047] FIG. 13a is a perspective view of the trigger mechanism of
the latch depicted in FIG. 13.
[0048] FIG. 13b is a perspective view of the trigger mechanism and
pawls for the latch of FIG. 13.
[0049] FIG. 14 is a left plan view of the mounting structure,
sleeve module, and latch mechanism, without trigger, of the
invention.
[0050] FIG. 15 is a rear plan view of the mounting structure,
sleeve module and latch mechanism in a locked state.
[0051] FIG. 15a is a partial sectional view of the system depicted
in FIG. 15, taken along line A-A.
[0052] FIG. 16 is a rear plan view of the mounting structure,
sleeve module and latch mechanism in an intermediate state.
[0053] FIG. 16a is a partial sectional view of the system depicted
in FIG. 16, taken along line A-A.
[0054] FIG. 17 is a rear plan view of the mounting structure,
sleeve module and latch mechanism in an unlocked state.
[0055] FIG. 17a is a partial sectional view of the system depicted
in FIG. 17, taken along line A-A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0056] With reference now to the drawings, the preferred embodiment
of the modular gunstock is herein described. It should be noted
that the articles "a", "an", and "the", as used in this
specification, include plural referents unless the content clearly
dictates otherwise.
[0057] With reference to FIGS. 1 and 2, the modular gunstock
comprises three main components. The first is a weapon mounting
structure 12 which is the actual attachment to the weapon (See,
FIG. 3). In the case of an AR15/M16 model weapon, the structure is
actually a replacement receiver extension tube. However the only
requirement is that the mounting structure 12 be cylindrical
(either round or polygonal) so that sleeve module 14 may slide over
it. As such, references to the mounting structure 12 as being an
extension tube should be construed as only relating to this
preferred and disclosed embodiment as alteration of the structure
for other weapon platforms that do not need a receiver extension
tube will be obvious permutations of the present invention and
should be read as included within this invention. Weapon mounting
structure features actual interfacing structure, in the case of
this preferred embodiment a threaded open end 26, and a threaded
nut 24 at its distal end. The preferred embodiment then simply
screws onto the weapon's lower receiver 30, shown in FIG. 3. It
should be noted that the key slot 32 is avoided by the invention at
this stage.
[0058] The second component is the sleeve module 14, which slides
over the mounting module 12, shown in FIGS. 2 and 4. ON the lower
half of sleeve module 14, is rail 52 which serves as structure for
the stock body. Rail also provides interface structure for yoke 42
and end cap 44. End cap 44 is attached and keyed into sleeve 14
between two prongs of rail 52. Bolt 22 is then used to secure end
cap 44 to threaded nut 24 on the mounting structure 12. Sleeve 14
is thereby secured to mounting structure 12 in a manner that
prevents rotation. Yoke 42 is positioned at a forward end of sleeve
14, on rail 52. It provides structure 41 to key into the receiver's
key slot 32, thereby preventing rotation in relation to lower
receiver 30. Yoke 42 is secured as a vice, biased by bolt 43, and
may provide additional useful structure as a quick-detach point for
certain accessories such as slings.
[0059] Sleeve module 14 also features a plurality of sets of
threaded holes 48a, 48b along its sides. These holes provide
mounting structure for cheek plate 46, as it is secured by
threading bolts 48 into one of each set 48a, 48b of holes,
depending on the location the user desires the cheek plate 46, as
shown. It should be understood that matching sets of holes are
ideally placed on the side not shown in the figures. As shown, the
sleeve module 14 provides three placement options for positioning
the cheek plate 46.
[0060] Rail 52, shown in FIG. 5, provides structure for mounting
the stock body and contains structure for the pre-set system
utilized by stock bodies which are adjustable for length. The
length of pull system comprises a series of pre-drilled threaded
holes 56, which are off-set from a center axis of the rail (shown
in better detail in FIG. 6a). A stop bolt 54 is provided to
interface with whichever hole 56 a user desires. End cap 44 also
provides a terminal stop 45, which is also off-set but opposite
holes 56. Angled detents 58 are provided for pawls in the latch
mechanism.
[0061] The length of pull pre-set system works as follows, shown in
FIGS. 6-12c. The stock is in a normal state, shown in FIGS. 6-6c,
where a stop bolt 54 is inserted in one threaded hole 56 and the
terminal stop 45 is in place. Release latch 88 is situated just
underneath the rail and is biased in a central orientation by
plunger 89, which is so biased by spring 89a. On top of release
latch 88, is an angled block 88a which will interface with stop
bolt 54 and terminal stop 45. In FIGS. 7-7c, the stock is depicted
as having been extended (moved back) until the block 88a abuts stop
bolt 54. As can be seen, the wide portion of the angled block 88a
actually abuts the stop bolt 54 and prevents the stock from being
further retracted. However, it should be noted that if the release
latch was on the other side of the stop bolt 54, the angled portion
of the block 88a would interface with the stop bolt 54 (if being
pushed forward) and would actually act as a lever, moving the
release latch 88 out of the way so that the stock could be
collapsed without engaging the release latch 88.
[0062] In order to avoid the stop bolt 54, the user presses the
release latch 88 to one side (FIGS. 8-8c). As the block 88a
circumvents the stop bolt 54, the stock may be retracted further
(FIGS. 9-9c) without hindrance, until it reaches the point of
terminal stop 45 (FIGS. 10-10c). It should be noted that in both
its natural stage (FIGS. 11-11c) and the biased stage (FIGS.
10-10c), the block 88a interfaces with the terminal stop 45.
Instead, to avoid the terminal stop 45, the release latch 88 must
be biased in the opposite direction as to avoid the bolt stop 54.
This is done intentionally so as to avoid accidental removal of the
stock from the system which only trying to avoid the bolt stop 54.
The release latch 88 maintains its central bias via spring loaded
plunger 89 which interfaces with a "V" shaped notch 88b on the
underside of the release latch 88. When the release latch 88 is
biased to one side or the other by the user, plunger 89 is
displaced by the walls of notch 88b and spring 89a is compressed
(FIGS. 8a, 9a, 10a, 12a). When the bias is released, spring 89a
decompresses, forcing plunger 89 forward and restoring release
latch 88 to its central orientation (FIGS. 6a, 7a, 11a) by pressure
against the notch 88b.
[0063] The latching mechanism is depicted in FIGS. 13-17a. As seen
in FIGS. 13-13b, the latch components are the latch housing 85,
which contains the shock cushion 86 and trigger structure 82. Lock
pawls 84 are mounted on the top of the housing 85. Lock pawls 84
are biased by springs 90 (FIGS. 15 & 16) in an upward
orientation. Trigger structure is also spring biased in an extended
position by latch spring 92, mounted upon post 94 in the housing
(FIG. 17a). Latch spring 92 rests inside orifice 87 in the trigger
structure (FIG. 13a). Trigger structure comprises the actual
trigger body 81 and two bias wedges 83, 93, to actuate lock pawls
84. As shown in FIG. 14, the latch mechanism resides below the rail
52 on the sleeve module 14. Pre-set latch 88 resides between the
latch mechanism and the rail 52.
[0064] In operation, the latch is usually in its locked position,
shown in FIGS. 15 and 15a, with lock pawls 84 resting within
detents in the rail 52. Lower wedge 83 provides a mechanical stop
to prevent the lock pawls 84 from accidentally being compressed. In
intermediate stages, the front slope of the wedge 83 actually
provides an assist to effectively and securely move the lock pawls
84 into their locked position (FIGS. 16 and 16a). To unlatch the
stock (FIGS. 17 and 17a), trigger body 81 is compressed against
trigger spring 92. This motion causes upper wedge 93 to approach a
pawl pin 91 that extends from each pawl 84 and push the pin 91
downward, compressing pawl springs 90 (not shown in FIGS. 17 and
17a) and lowering the lock pawls 84. This then allows the stock
body to slide transversely along the rail 52, subject to the
pre-set system. It should be noted that the lock pawl pins 91 do
not join the lock pawls 84 together. The lock pawls 84 operate
independently of each other so that failure of one, especially in
the open position, may be compensated by the action of the
other.
[0065] Other features of the stock body, in its preferred
embodiment and shown in FIGS. 1 and 2, include a storage
compartment 62, formed by having a hollow body enclosed by
attachable walls. One of said walls may be capable of opening
without removal. The stock also features a removable tailpiece 64.
Tailpiece 64 provides structural support and may be designed to
protrude from the stock body (as shown in FIG. 2) with a sling loop
or with other useful structure, like a glass strike plate. A
rubberized butt pad 66 may also be provided to provide some shock
absorption when impacts occur, either intentionally or
unintentionally. It should be noted that other stock bodies, each
with their own set of desirable features, may be designed and used
with the described mounting system. As such, no limitation in the
claims to the preferred stock body as described herein should be
inferred, but only read into the claims where the specific
structures of the preferred stock body are directly claimed.
[0066] Although the present invention has been described with
reference to preferred embodiments, numerous modifications and
variations can be made and still the result will come within the
scope of the invention. No limitation with respect to the specific
embodiments disclosed herein is intended or should be inferred.
* * * * *