Patent Abstract:
The present invention is an ammunition magazine, preferably made of a 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.

Full Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §120   
       [0001]    The present application for Patent is a Continuation-in-Part of patent application Ser. No. 14/098,467 entitled “Ammunition Magazine” filed Dec. 5, 2013, which is a Continuation of patent application Ser. No. 13/307,431 entitled “Ammunition Magazine” filed Nov. 30, 2011 and issued on Jan. 28, 2014 as U.S. Pat. No. 8,635,796, which is a Continuation of prior filed U.S. application Ser. No. 12/354,766, filed Jan. 15, 2009 and issued on Dec. 6, 2011 as U.S. Pat. No. 8,069,601 which, in turn, is a Continuation-in-Part of prior filed U.S. application Ser. No. 11/958,274, filed on Dec. 17, 2007 issued on Mar. 22, 2011 as U.S. Pat. No. 7,908,780, which, in turn, claims priority to earlier filed U.S. Provisional Application No. 60/941,646, filed on Jun. 1, 2007. Each of these patents and applications are assigned to the assignee hereof and are hereby expressly incorporated by reference herein. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present invention relates to the field of firearms and more particularly relates to an improved ammunition magazine. 
       BACKGROUND 
       [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 DISCLOSURE 
       [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&#39;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. 6   a  is a perspective view of the floor and lock plates according to the present invention. 
           [0019]      FIG. 6   b  is a side plan view of the floor and lock plates of  FIG. 6   a.    
           [0020]      FIG. 6   c  is an alternative perspective view of the floor and lock plates of  FIG. 6   a.    
           [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. 9   a  is a side plan view of the follower of  FIG. 9 . 
           [0025]      FIG. 9   b  is a front plan view of the follower of  FIG. 9 . 
           [0026]      FIG. 9   c  is a rear plan view of the follower of  FIG. 9 . 
           [0027]      FIG. 9   d  is a bottom plan view of the follower of  FIG. 9 . 
           [0028]      FIG. 9   e  is a sectional view of the follower of  FIG. 9   d , taken along line  9   e - 9   e.    
           [0029]      FIG. 10  is a perspective view of the impact cover according to the present invention. 
           [0030]      FIG. 10   a  is a side plan view of the impact cover of  FIG. 10 . 
           [0031]      FIG. 10   b  is a front plan view of the impact cover of  FIG. 10 . 
           [0032]      FIG. 10   c  is a rear plan view of the impact cover of  FIG. 10 . 
           [0033]      FIG. 10   d  is a bottom plan view of the impact cover of  FIG. 10 . 
           [0034]      FIG. 10   e  is a sectional view of the impact cover of  FIG. 10   d , taken along line  10   e - 10   e.    
           [0035]      FIGS. 11   a - 11   c  are successive plan views showing use of the impact cover as a magazine unloading tool. 
           [0036]      FIGS. 12   a - 12   c  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&#39;s external components, along the same section line as  FIG. 19 . 
           [0046]      FIG. 22  is a sectional view of the magazine&#39;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 
       [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  (see  FIG. 6   a ), 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. 6-6   c ), 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&#39;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 0.223 Remington caliber magazine, as shown in  FIGS. 19-22 . The factors that govern this dimension relate to cartridge size, stripper clip design and geometry, the method used to move the cartridges from the stripper clip to the magazine, and the number of rounds on the stripper clip, among other factors. 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 into the weapon, the guide rails  31  should terminate  31   a  at approximately a cartridge&#39;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 about ¼ inch for a 0.223 Remington magazine or 5/16 of an inch for a .308 Winchester caliber magazine. This is, however, only for certain embodiments, as the guide rails  31  can extend the entire length of the magazine body  10  and the magazine will still be functional. 
         [0059]    As shown in  FIGS. 9-9   e,  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 inhibits axial and lateral movement as the extension increases contact with the magazine body and provides more counter-torque when forces would cause such movement. The follower also has two lateral arms  36  that fit alongside of the guide rails  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 . In some embodiments, the hind tine  37  can be excluded and the interaction of the lateral arms  36  and the guide rails  31  can be a primary inhibitor of rotation of the follower. In other embodiments, the one or more tines  33 ,  37  can be split via a vertical separation or gap (not illustrated). 
         [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 ,  9   b , and  9   e ). 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. In an embodiment, the 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 an embodiment, the magazine body is comprised of a reinforced thermoplastic polymer selected to resist damage from use (e.g., the ejection of a magazine which causes the magazine to impact a hard surface, which may occur during a speed reload). However, other polymers 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 may be used without reinforcement. Various reinforcement materials, such as glass, carbon (e.g., carbon fiber or carbon nanotubes), minerals, or metals (e.g., steel, titanium, aluminum, etc.) 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, or acetal resin, available commercially from DuPont under the trade name DELRIN, 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. 10-10   e,  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 redirecting 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 ( 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. 11   a - 11   c ). 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 ( FIGS. 10-10   e ). 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 by 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. 12   a - 12   c ). 
         [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.

Technology Classification (CPC): 5