U.S. patent application number 12/354766 was filed with the patent office on 2011-12-15 for ammunition magazine.
This patent application is currently assigned to MAGPUL INDUSTRIES CORP.. Invention is credited to Eric C. Burt, Richard M. Fitzpatrick, Michael T. Mayberry, Brian L. Nakayama.
Application Number | 20110302816 12/354766 |
Document ID | / |
Family ID | 41129269 |
Filed Date | 2011-12-15 |
United States Patent
Application |
20110302816 |
Kind Code |
A1 |
Fitzpatrick; Richard M. ; et
al. |
December 15, 2011 |
AMMUNITION MAGAZINE
Abstract
The present invention is an ammunition magazine, preferably made
of a glass fiber reinforced polymer, utilizing a structurally
enhancing ridge, angular guide rails and a follower made to
interface with said guide rails to reduce wobble. The preferred
embodiment also features a protective cover that distributes forces
from the spring to more structurally sound areas of the magazine,
thus reducing feed end splay, and an ammunition indication system
comprised of at least one window and a noticeable marker on the
follower spring. The follower and magazine casing are also designed
to interface to prevent the follower from popping out of the feed
end and the floor plate of the magazine utilizes a locking plate
and sliding relationship between the floor plate, locking plate and
magazine to secure the floor plate onto the magazine casing. The
cover features built in tools for, among other things, unloading
and disassembling the magazine.
Inventors: |
Fitzpatrick; Richard M.;
(Longmont, CO) ; Mayberry; Michael T.; (Denver,
CO) ; Nakayama; Brian L.; (Arvada, CO) ; Burt;
Eric C.; (Broomfield, CO) |
Assignee: |
MAGPUL INDUSTRIES CORP.
Boulder
CO
|
Family ID: |
41129269 |
Appl. No.: |
12/354766 |
Filed: |
January 15, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11958274 |
Dec 17, 2007 |
7908780 |
|
|
12354766 |
|
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Current U.S.
Class: |
42/50 |
Current CPC
Class: |
F41A 9/70 20130101; F41A
9/83 20130101; F41A 9/69 20130101; F41A 9/65 20130101; F41A 9/62
20130101 |
Class at
Publication: |
42/50 |
International
Class: |
F41A 9/65 20060101
F41A009/65; F41A 9/61 20060101 F41A009/61 |
Claims
1. An ammunition magazine comprising: a. A casing having a mostly
rectangular cross-section with fore and aft sides and two longer
lateral sides and first and second open ends, the casing further
comprising: i. two guide rails extending a length of the magazine,
each one situated along the lateral sides in an interior of the
casing, the guide rails extending at least mostly to the first open
end and each presenting a flat forward surface, roughly parallel to
the fore side; ii. a ridge, centrally located on an interior side
of the fore side and extending to a terminus located at least
mostly, but not entirely, to the first open end; b. A follower
residing within the casing, said follower further comprising: i. A
follower platform with two opposite tines at fore and aft positions
and extending generally perpendicularly and distally therefrom; ii.
Two side fins situated to interface with the casing's guide rails;
c. A floor plate capable of interfacing the casing at the second
end; and d. A follower spring residing between the follower and
floor plate; wherein the tines and the side fins limit rotation of
the follower within the casing.
2. The magazine of claim 1, further comprising a stop tab,
projecting internally from the ridge terminus and generally
perpendicularly from the fore side, and a groove serving as a
detent, situated in the follower platform to interface with stop
tab, thereby preventing the follower from exiting the magazine
through the first end.
3. The magazine of claim 1, further comprising at least one window
in the casing, through which the spring is viewable.
4. The magazine of claim 1, the magazine further comprising a rim
about the second end and the floor plate being capable of a sliding
relationship over said rim.
5. The magazine of claim 4, the floor plate further comprising an
interior locking plate with a locking tab and a floor plate cover
with a mating slot and a ledge capable of interfacing with the rim,
the interior locking plate also having at least one support wall
extending therefrom on a side opposite the locking tab.
6. The magazine of claim 5, further comprising a stop tab,
projecting internally from the ridge terminus and a detent,
situated in the follower platform to interface with tab, thereby
preventing the follower from exiting the magazine through the first
end.
7. The magazine of claim 4, further comprising a stop tab,
projecting internally from the ridge terminus and generally
perpendicularly from the fore side, and a groove serving as a
detent, situated in the follower platform to interface with stop
tab, thereby preventing the follower from exiting the magazine
through the first end.
8. The magazine of claim 1, further comprising a constant internal
curve initiating at the second open end and continuing through a
majority of the casing of the magazine, though not as far as the
guide rails.
9. The magazine of claim 8, the magazine further comprising a rim
about the second end and the floor plate being capable of a sliding
relationship over said rim.
10. The magazine of claim 9, the floor plate further comprising an
interior locking plate with a locking tab and a floor plate cover
with a mating slot and a ledge capable of interfacing with the rim,
the interior locking plate also having having at least one support
wall extending therefrom on a side opposite the tab.
11. The magazine of claim 10, further comprising a stop tab,
projecting internally from the ridge terminus and generally
perpendicularly from the fore side, and a groove serving as a
detent, situated in the follower platform to interface with stop
tab, thereby preventing the follower from exiting the magazine
through the first end.
12. The magazine of claim 9, further comprising a stop tab,
projecting internally from the ridge terminus and generally
perpendicularly from the fore side, and a groove serving as a
detent, situated in the follower platform to interface with stop
tab, thereby preventing the follower from exiting the magazine
through the first end.
13. The magazine of claim 1, further comprising a protective cover
and interfacing geometry on the casing with which to secure the
protective cover, the protective cover capable of forcing the
follower downward and absorbing at least some pressure applied to
the magazine by the spring.
14. The magazine of claim 13, further comprising a constant
internal curve through a majority of the length of the
magazine.
15. The magazine of claim 14, the magazine further comprising a rim
about the second end and the floor plate being capable of a sliding
relationship over said rim.
16. The magazine of claim 15, the floor plate further comprising an
interior locking plate with a locking tab and a floor plate cover
with a mating slot and a ledge capable of interfacing with the rim,
the interior locking plate also having having at least one support
wall extending therefrom on a side opposite the tab.
17. The magazine of claim 16, further comprising a stop tab,
projecting internally from the ridge terminus and generally
perpendicularly from the fore side, and a groove serving as a
detent, situated in the follower platform to interface with stop
tab, thereby preventing the follower from exiting the magazine
through the first end.
18. The magazine of claim 17, the magazine casing being made from a
fiber-reinforced polymer.
19. The magazine of claim 15, further comprising a stop tab,
projecting internally from the ridge terminus and generally
perpendicularly from the fore side, and a groove serving as a
detent, situated in the follower platform to interface with stop
tab, thereby preventing the follower from exiting the magazine
through the first end.
20. The magazine of claim 19, the magazine casing being made from a
fiber-reinforced polymer.
21. The magazine of claim 13, the protective cover further
comprising at least one tool portion.
22. The magazine of claim 21, the at least one tool portion being
at least one tool selected from the set of magazine tools
consisting of: a magazine unloading tool, a magazine disassembly
tool, and a feed lip width gauge.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This Application claims priority on prior filed U.S.
application Ser. No. 11/958,274, filed on Dec. 17, 2007, which in
turn claims priority on earlier filed U.S. Provisional Application
No. 60/941,646, filed on Jun. 1, 2007. This Application
incorporates both in their entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of firearms and
more particularly relates to an improved ammunition magazine.
BACKGROUND OF THE INVENTION
[0003] Ammunition magazines are well known in the art of firearms.
Their basic construction is a containment shell with two open ends.
One end is deemed the "floor" of the magazine and is covered by a
plate while the opposite end is the "feed" end and interfaces with
the weapon. Inside the volume defined by the shell and plate is a
spring and follower assembly. When ammunition is loaded into the
magazine, the ammunition pushes the follower down towards the floor
and thereby compresses the spring. In use, when one cartridge of
ammunition is expended, the compressed spring releases and pushes
the follower and associated ammunition upwards toward the feed end
and the next round of ammunition is thereby readied.
[0004] Prior magazines have been manufactured in many different
configurations and of different materials. Perhaps the best known
in the U.S. are the AK-47 and the USGI AR15/M16 magazines. These
magazines function similarly, though they are made with slight
variations to interface with their host system. Of notable
difference is that the AK-47 magazine has a relatively constant
curvature while the AR15/M16 magazine has a less curved lower
region that gradually resolves to a more linear function towards
the feed end. Both use the same type of internal system. Of
particular note with both, and all follower magazine systems, is
that the system works well only as the follower smoothly and
levelly travels the inside of the magazine. As the follower must
move, there is room for the follower in all the known prior art
magazines to move axially, or "wobble" and possibly jam. This is
notorious in the AR15/M16 magazine style as the geometry of the
magazine is inherently not uniform.
[0005] The present invention is a polymer magazine with angularly
shaped guide rails to interface with the internal follower, thereby
restricting axial motion of the follower. The magazine also
features a load indicator and a two-piece floor plate locking
system. The present invention represents a departure from the prior
art in that the magazine of the present invention allows for more
stable and level motion of the follower while the magazine is
loaded or unloaded.
SUMMARY OF THE INVENTION
[0006] In view of the foregoing disadvantages inherent in the known
types of ammunition magazines, this invention provides an improved
magazine. As such, the present invention's general purpose is to
provide a new and improved magazine that is backwards compatible
with known weapon platforms and presents a more stable follower and
follower path.
[0007] To accomplish these objectives, the improved ammunition
magazine comprises a plurality of lateral angularly shaped guide
rails within the magazine shell and a follower that is configured
to abut them. By interfacing with more internal structure, all
non-advantageous linear and axial motion is inhibited and the
follower is then more stable in its progress. The magazine also
features a polymer construction and an ammunition load indicator
system. The magazine also features a cover for storage.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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
[0012] FIG. 1 is an exploded view of the magazine according to the
present invention.
[0013] FIG. 2 is a perspective view of the assembled magazine
according to the present invention.
[0014] FIG. 3 is a side plan view of the magazine of FIG. 2.
[0015] FIG. 4 is a perspective view of the magazine according to
the present invention, without the impact cover.
[0016] FIG. 5 is a hind plan view of the magazine of FIG. 4.
[0017] FIG. 6 is a sectional view of the magazine in FIG. 5, taken
along line 6-6.
[0018] FIG. 6a is a perspective view of the floor and lock plates
according to the present invention.
[0019] FIG. 6b is a side plan view of the floor and lock plates of
FIG. 6a.
[0020] FIG. 6c is an alternative perspective view of the floor and
lock plates of FIG. 6a.
[0021] FIG. 7 is a bottom plan view of the magazine body, according
to the present invention.
[0022] FIG. 8 is a cross-section of the magazine body of FIG. 7,
taken along line 8-8 and re-orientated with the bottom down.
[0023] FIG. 9 is a perspective view of the follower according to
the present invention.
[0024] FIG. 9a is a side plan view of the follower of FIG. 9.
[0025] FIG. 9b is a front plan view of the follower of FIG. 9.
[0026] FIG. 9c is a rear plan view of the follower of FIG. 9.
[0027] FIG. 9d is a bottom plan view of the follower of FIG. 9.
[0028] FIG. 9e is a sectional view of the follower of FIG. 9d,
taken along line 9e-9e.
[0029] FIG. 10 is a perspective view of the impact cover according
to the present invention.
[0030] FIG. 10a is a side plan view of the impact cover of FIG.
10.
[0031] FIG. 10b is a front plan view of the impact cover of FIG.
10.
[0032] FIG. 10c is a rear plan view of the impact cover of FIG.
10.
[0033] FIG. 10d is a bottom plan view of the impact cover of FIG.
10.
[0034] FIG. 10e is a sectional view of the impact of FIG. 10d,
taken along line 10e-10e.
[0035] FIGS. 11a-11c are successive plan views showing use of the
impact cover as a magazine unloading tool.
[0036] FIGS. 12a-12c are successive plan views showing use of the
impact cover to disassemble the magazine.
[0037] FIG. 13 is a side plan view of an alternate embodiment of
the magazine according to the present invention.
[0038] FIG. 14 is a rear perspective view of the magazine of FIG.
13.
[0039] FIG. 15 is a bottom plan view of the magazine of FIG.
13.
[0040] FIG. 16 is a side plan view of the magazine of FIG. 13, with
the impact cover in a stowed position on the magazine.
[0041] FIG. 17 is a rear perspective view of the magazine of FIG.
16.
[0042] FIG. 18 is a bottom plan view of the magazine of FIG.
16.
[0043] FIG. 19 is a sectional view of the magazine of FIG. 16.
[0044] FIG. 20 is a sectional view of the magazine of FIG. 17.
[0045] FIG. 21 is a sectional view of the magazine's external
components, along the same section line as FIG. 19.
[0046] FIG. 22 is a sectional view of the magazine's external
components, along the same section line as FIG. 20.
[0047] FIG. 23 is a left, front, top perspective view of a follower
for the alternative magazine embodiment depicted in FIG. 13.
[0048] FIG. 24 is a left, rear, top perspective view of the
follower of FIG. 23.
[0049] FIG. 25 is a top plan view of the follower of FIG. 23.
[0050] FIG. 26 a left plan view of the follower of FIG. 23.
[0051] FIG. 27 is a front plan view of the follower of FIG. 23.
[0052] FIG. 28 is a rear plan view of the follower of FIG. 23.
[0053] FIG. 29 is a bottom plan view of the follower of FIG.
23.
[0054] FIG. 30 is a left, front, bottom perspective view of the
follower of FIG. 23.
[0055] FIG. 31 is a left, rear, bottom perspective view of the
follower of FIG. 23.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0056] With reference now to the drawings, the preferred embodiment
of the ammunition magazine 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 FIG. 1, the magazine 1 generally comprises
a body 10 having a floor end 13 and a feed end 17. Feed lips 21 are
provided at the feed end 17 to interface with a weapon and to guide
cartridges into the firing chamber of said weapon. The floor end is
capped with a floor plate 20 which is secured by a lock plate 25. A
spring 35 rests against the lock plate 25, centered by walls 24,
and floor plate 20 combination and provides tension to bias the
follower 30 and the floor plate 20 so that the follower 30 will
progress up the magazine body 10 as ammunition is used. Floor plate
20 slides over a rim 23 of the floor end 13, using a ledge to
interface with the rim, and simultaneously over the lock plate 25.
The floor plate 20 and lock plate 25 interface together with a tab
26 on the lock plate resting within a slot 27 of the floor plate
(shown in FIGS. 6-6c), so, with the floor plate 20 holding the
magazine 1 and the lock plate 25 holding the floor plate 20
laterally, as it is forced against the floor plate 20 by the
spring, the floor plate 20 does not slide off the magazine 1. A
protective impact cover 40 is also provided for use during storage.
Magazine 1 also features two indicator windows 15 to view the
spring. An indicator, which could be as simple as a colored dot or
a dab of properly placed paint, is positioned on the spring and is
viewable through the windows when the magazine 1 is assembled.
Ideally, the windows 15 are positioned on either side of the
magazine body 10 and are close enough to the floor end so that they
are not obscured when the magazine 1 is inserted in a weapon's
magazine well. FIGS. 2-4 provide views of the magazine 1 assembled,
FIG. 4 without the impact cover 40.
[0058] Inside the body 10, along the fore side of the magazine 1,
is a ridge 19, shown in FIGS. 6, 7, and 8. The ridge serves three
purposes. The first purpose is to provide additional stability and
strength to the magazine body 10. The second purpose is to divide
tips of cartridges, left from right, in their off-set stacking in
the magazine. The third purpose is to provide an additional
interface with the follower 30 to prevent forward linear and axial
tilt. In order to accommodate stripper clips, the ridge 19 may
terminate at a point significantly below the feed lips, about 0.5
inches for a .223 caliber magazine, as shown in FIGS. 19-22. The
body also has two lateral guide rails 31 extending through the body
10. The guide rails 31 are flattened in front and angular towards
the rear so as to present a more solid surface for the follower to
abut and to guide cartridges as they travel through the magazine
body 10. So as to not interfere with feeding of cartridges in to
the weapon, the guide rails 31 should terminate 31a at
approximately a cartridge's diameter of the feed end 17 of the
magazine body (as defined by the level where the rib 19 terminates
with tab 29), or within 1/4 inch for a .223 magazine. This is,
however, only for the preferred embodiment, as the guide rails 31
can extend the entire length of the magazine body 10 and the
magazine will still be functional, just not preferred.
[0059] As shown in FIGS. 9-9e, the follower 30 has two tines, a
forward tine 33 and hind tine 37. Both tines are elongated and
extending from platform 34. The forward tine 33 presses against the
ridge 19 and prevents axial movement, particularly those movements
caused by the simple act of firing the weapon, which would push the
rear of the ammunition (and the follower 30) down. The hind tine 37
fits into trough 11 (FIG. 7) to prevent lateral movement. The
extension of the tines greatly inhibit axial and lateral movement
as the extension increases contact with the magazine body and
provide more counter-torque when forces would cause such movement.
The follower also has two lateral arms 36 that fit alongside of the
lateral fins 31 to further inhibit rotation. The follower 30
interfaces with spring 35 by attachment of the spring 35 to loop 38
and retention of the spring 35 by retaining wall 32.
[0060] At the top of ridge 19 is a slight tab 29 (FIGS. 6 and 8)
that protrudes towards the interior of the magazine 1. Tab 29
serves as a block to prevent the follower 30 from exiting the feed
end 17 of the magazine 1. It interfaces with a detent 39 provided
in the follower 30 (FIGS. 9, 9b, and 9e). In the embodiment shown
in FIGS. 19-22, the tab 29 is, of course, lower in relation to the
feed lips. The follower 30 then, as shown in FIGS. 23-31 has a
chamfered groove 90 so as to allow the follower 30 to still be
blocked, but in a manner that allows it to fully rise in relation
to the magazine. The groove 90 also allows further interface to
reduce disadvantageous tilt in the follower. Lock plate 25 may also
feature a ridge 96 to interface with the bottom of the follower 30
when the magazine is fully loaded, so as to support the follower 30
and round stack and reduce spring fatigue, as shown in FIGS.
19-22.
[0061] In the preferred embodiment, the magazine body is comprised
of a long glass-reinforced thermoplastic polymer selected to resist
the heat generated from firing a rifle. However, other polymers,
like polycarbonate, may be used and the magazines may be made in
any color or opacity (which can reduce or eliminate the need for a
magazine level indicator). Some polymers, such as polycarbonate,
may be used without reinforcement. Other reinforcement materials,
such as steel, carbon fiber, or other materials may also be used to
reinforce the magazine. Likewise, the magazine body may be made of
other materials having suitable strength and durability, such as
titanium, ceramics, laminates, amorphous metals, etc. The follower
is preferred to be made of polyoxymethylene, acetal resin available
commercially from DuPont under the trade name DELRIN.RTM., though
other materials are suitable, just not preferred.
[0062] The magazine 1 is structured to increase its structural
integrity. To that end, fore ridge 19 provides added durability to
the magazine. Protective cover 40 also provides reinforcement
during storage, as pressures from the stored ammunition and spring
35 would normally force the feed lips 21 of the magazine 1 apart.
Protective cover 40, shown in FIGS. 10-10e, interfaces with
geometry, namely notch 44 and hinge base 48, on the magazine body
10 with latch 43 and cover hinge 47 (FIGS. 2, 3 and 4), and forces
the ammunition downward with an underside spacer 45, thereby
absorbing and distributing the forces that would normally be
applied to the feed lips 21 in a more advantageous manner. Geometry
92 may be added to the magazine to allow the cover to fasten on the
bottom of the magazine for storage as well (FIGS. 13-18). A double
notch 94 may be utilized (FIG. 17) as this geometry can benefit the
molding process.
[0063] The cover 40 also serves as a magazine tool as the cover
latch 43 will fit between the feed lips 21 so as to push rounds of
ammunition 50 out of the magazine 1 (FIGS. 11a-11c). It also has a
specialized gauge 49 to determine if the feed lips 21 have either
splayed or compressed in a manner to prevent operability of the
magazine with the weapon. Gauge 49 is a flared area, specially
sized depending upon the size of ammunition, slightly above latch
43. The operable magazine 1 will accommodate the latch 43 between
the feed lips 21, but not the gauge. If the latch 43 is unable to
fit between feed lips 21, then the feed lips 21 have compressed in
some manner, perhaps due to impact or compression damage, and the
magazine 1 is then not fit for use. If the gauge 49 is able to fit
between feed lips 21, then the feed lips 21 have splayed, perhaps
due to long term storage without the impact cover 40, and the
magazine 1 is not fit for use. Measurements of the gauge and latch
widths will be dependent upon the type of ammunition used.
Likewise, this magazine 1 is capable of being used in multiple
weapon platforms, each with its own tolerances. The widths of the
latch 43 and gauge 49 would be dependent upon those tolerances and
different weapon platforms may be accommodated my merely fashioning
a different version of the impact cover 40 for that platform,
without changing the magazine as a whole. Impact cover 40 may also
be used to depress the locking plate tab 26 so as to remove the
floor plate 20 (FIGS. 12a-12c).
[0064] It should also be noted that magazine body 10 presents a
constant internal curve, with slight straightening near the
interior rear face of the feed lips only to allow interface with a
weapon. As such, the follower 30 and associated ammunition travel
more smoothly through the magazine body 10 with lessened round
stack variation.
[0065] 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.
* * * * *