Patent Abstract:
An ammunition feed adapter and method of use is provided that converts a semi-automatic or fully automatic firearm from a magazine-fed firearm into a belt-fed firearm enabling the firearm to be used as a sustainable source of firepower. Modification of a soldier&#39;s standard issue automatic or semi-automatic rifle into a belt-fed firearm increases the options for strategic maneuvering of a combat unit on the field of battle by overcoming the limitations of traditional sources of sustained firepower, such as a Squad Automatic Firearm.

Full Description:
PRIORITY 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 61/050,020, filed May 2, 2008, which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    The present invention relates to adapters for firearms. More specifically, the present invention relates to an adapter for modifying a firearm, designed to accept a magazine, to accept cartridges from an ammunition belt so as to provide the firearm with an increased supply of ammunition without requiring the changing magazines. 
       BACKGROUND 
       [0003]    When deployed in the field, soldiers are often faced with situations where a means of sustained firepower is desirable to deal with a specific threat on the battlefield. The traditional means of such firepower is a Squad Automatic Weapon (SAW). A SAW is a dedicated belt-fed gun which is configured to fire in a fully automatic mode for a prolonged length of time. A combat unit&#39;s source of sustained firepower is a key consideration when making strategic choices about how to best defend a position or otherwise maneuver. 
         [0004]    However, a particular combat unit may not even have a SAW assigned to it. Or, when a unit has been assigned a SAW, the soldiers operating it may not be able to utilize the weapon effectively. A typical reason why the SAW has limited effectiveness is because the cartridge belts used to feed the SAW are distributed among several members of the unit, and those unit members can become separated from the SAW&#39;s operators. When the SAW&#39;s effectiveness is limited, the unit must rely on the automatic and semi-automatic magazine-fed firearms carried by individual members of the squad in order to maneuver. The lack of sustained firepower limits the unit&#39;s effectiveness in the field and jeopardizes the lives of soldiers. 
         [0005]    There are several other reasons why a combat unit may be unable to properly utilize its SAW. First, the SAW&#39;s weight, size, and the number of personnel it may require for operation create problems. These characteristics of the SAW make adjusting a defensive perimeter in response to changing situations difficult. Overall, the SAW&#39;s unwieldiness limits its strategic use in response to the large variation in circumstances encountered on the battlefield. For example, if three soldiers are carrying ammunition for the SAW and they come under hostile fire, it is common for them to have to throw ammunition to the soldier operating the SAW while avoiding being shot by the enemy. If the ammunition does not make it to those operating the SAW, the SAW may quickly run out, leaving the soldiers to rely on their rifles or other light firearms. 
         [0006]    Second, it is not uncommon for an enemy to target the SAW in an initial attack. A sniper, for example, appreciates that the SAW can cause considerable damage to his or her fellow soldiers. Thus, the soldier holding the SAW will often be the initial target of the sniper, hoping to deprive the unit of its automatic firearm, and its suppressive fire capabilities, when hostilities begin. If that soldier is hit, the squad is placed at a significant disadvantage in an ensuing fire-fight, especially if other soldiers are under fire and cannot make it to the SAW. 
         [0007]    Other factors that limit the SAW&#39;s use are: its complexity and need for special training to use; ammunition is often distributed throughout the unit and therefore unavailable when individual unit members become separated; and a stationary firearm requires a more defined position. In the absence of a source of sustained firepower, such as a SAW, the combat unit must rely on the semi-automatic and fully automatic firearm carried by the individual members of the unit when planning strategic maneuvering on the battlefield. Additionally, the SAW is generally heavier and more difficult to maneuver, and includes a spare barrel and ammunition above the amount carried by a rifleman. 
         [0008]    The automatic or semi-automatic firearms carried by the individual soldiers are fed by magazines that typically hold 20-30 rounds of ammunition. If the firearm is a full automatic, the firearm will often be able to empty the entire magazine within a matter of a few seconds. Thus, a soldier may attempt to move from cover and fire only to find out that the magazine has just run out of ammunition, or runs out while the soldier is still moving. 
         [0009]    To limit such situations, some automatic firearms will have a “burst” mode, wherein the firearm will shoot a number of bullets, typically three, with each pull of the trigger. However, in a fire-fight, burst mode may be inadequate to deal with the situation. Rather, a soldier may wish to be able to use a firearm in a full automatic mode for more than three or four seconds at a time. A firearm which is capable of firing 400 rounds per minute is significantly less effective than it could be if the user must change the magazine 12-15 times to fire that many rounds. 
         [0010]    To overcome the problem of a continuous need to change magazines, a SAW is belt-fed. A belt may hold many times as many rounds as a magazine and belts often can be attached to one another to provide a virtually endless supply of ammunition. Most firearms carried by the other members of the squad, however, are designed to operate using magazines and will not accept belt-fed ammunition. 
         [0011]    Thus there is needed a means for providing a combat unit with sustained firepower which allows the unit to immediately and effectively respond to the constantly changing situations on a battlefield. More specifically, there is a need for a system for the rapid conversion of a magazine-fed firearm into a belt-fed firearm. 
       SUMMARY 
       [0012]    Embodiments of an adaptor to provide for modifying a firearm to accept belt-fed ammunition, and related methods, are disclosed. 
         [0013]    In some embodiments, an ammunition feed adapter for converting a magazine-fed firearm to use an ammunition belt to provide a continuous source of ammunition. The ammunition feed adapter may be relatively lightweight, easy to use and manufacture, and can be designed for use with a variety of magazine-fed firearms. 
         [0014]    According to some embodiments, an ammunition feed adapter may quickly modify firearms that are designed to receive cartridges from a magazine into a firearm that can receive ammunition from a linked ammunition belt. Magazine-fed firearms modified with the ammunition feed adapter of the present invention are converted into a source of sustained firepower and allow multiple members of a squad to operate in a full automatic mode for much longer than a magazine will allow. In some embodiments, no modification to the firearm may be needed to use the feed adaptor. 
         [0015]    According to another embodiment, the ammunition feed adapter may use only the recoil of the host firearm&#39;s action as a source of mechanical energy to provide a continuous feed of ammunition to said firearm. 
         [0016]    According to another embodiment, the ammunition feed adapter may be connected to the host firearm through a cartridge lift follower body assembly in the same manner in which a ammunition magazine would be connected to the same firearm. The cartridge lift follower body assembly introduces a de-linked cartridge from the ammunition belt into the host firearm&#39;s firing mechanism. 
         [0017]    According to other embodiments, the ammunition feed adapter may receive cartridges from an ammunition belt using a belt puller assembly. The belt puller assembly positions a linked cartridge for entry into the cartridge lift follower body. The action of the belt puller assembly is coupled to, and driven by, the mechanical force generated by the host firearm&#39;s action. 
         [0018]    Similarly, cartridges from the ammunition belt that are received by the belt puller assembly and transferred to the cartridge lift follower body assembly, may be de-linked by a de-linker assembly. The de-linker assembly is also coupled to, and driven by, the mechanical force generated by the host firearm&#39;s action. 
         [0019]    In other embodiments, the mechanical force supplied to the belt puller assembly and the de-linker assembly may be transferred through and coordinated by an operating rod assembly and timing plate assembly respectively. The operating arm assembly may be attached to the host firearm&#39;s action, such as a bolt mechanism. Manually charging of the firearm or discharge of a cartridge, i.e. the opening and closing of the firearm&#39;s action, moves the operating arm assembly forwards and backwards, providing the mechanical energy for the operation of the belt puller assembly. In some embodiments, the operating arm assembly can coordinate the forward and backwards movement of the de-linker assembly. 
         [0020]    In addition, according to another embodiment, the operating arm assembly transfers the mechanical energy from the host firearm&#39;s action to the timing plate assembly. In turn the timing plate assembly drives and coordinates the actions of the belt puller assembly and, additionally, the introduction of a cartridge by the cartridge lift assembly. Also, an optional forward firearm mount assembly can be used to further stabilize the ammunition feed adapter during use. 
         [0021]    In accordance with still another embodiment, the ammunition feed adapter may be transferred from firearm to firearm. Thus, for example, if the ammunition feed adapter is being used with one automatic firearm and the barrel of the firearm begins to overheat, the ammunition feed adapter can be transferred to another firearm to sustain continued automatic fire capability. 
         [0022]    These and other aspects of embodiments of an ammunition feed adapter, and related methods, are shown and described in the following figures and related description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein: 
           [0024]      FIG. 1  shows a side view of one embodiment of the ammunition feed adapter according to the present invention; 
           [0025]      FIG. 2  shows a top view of the ammunition feed adapter; 
           [0026]      FIG. 3A  shows a side, cutaway view of the cartridge lift follower body; 
           [0027]      FIG. 3B  shows a front view of one embodiment of the cartridge lift follower body; 
           [0028]      FIG. 3C  shows a side view of the cartridge lift follower and associated parts according to one embodiment of the present invention; 
           [0029]      FIG. 3D  shows a top view of the cartridge lift arm assembly according to one embodiment of the present invention; 
           [0030]      FIG. 3E  shows a side view of the cartridge lift arm assembly; 
           [0031]      FIG. 4A  shows a perspective view of one embodiment of the belt puller tray; 
           [0032]      FIG. 4B  shows a side view of one embodiment of the belt lock assembly; 
           [0033]      FIG. 4C  shows a side, cutaway view of the belt puller assembly in the set position; 
           [0034]      FIG. 4D  shows a side, cutaway view of the belt puller assembly moving a cartridge to the load position; 
           [0035]      FIG. 4E  shows a side view of the belt puller assembly as it moves beneath the cartridge when returning to the set position. 
           [0036]    FIG.  4 F(a) shows a side and end view of one embodiment of the puller arm; 
           [0037]    FIG.  4 F(b) shows a perspective view of one embodiment of the belt puller arms; 
           [0038]      FIG. 4G  shows one embodiment of the spring guide arms; 
           [0039]      FIG. 5A  shows the timing plate in its full back position; 
           [0040]      FIG. 5B  shows the timing plate in its full forward position; 
           [0041]      FIG. 6  shows a side and top view (top and bottom respectively) of the operating arm assembly and its engagement with the de-linker latch according to one embodiment of the present invention; 
           [0042]      FIG. 7A  shows a side view of the ammunition feed adapter with a more detailed cutaway view of the de-linker assembly according to one embodiment of the present invention; 
           [0043]      FIG. 7B  shows a top, cutaway view of the de-linker assembly; 
           [0044]      FIG. 7C  shows a side, cutaway view of the de-linker rod and associated components according to one embodiment of the present invention; 
           [0045]      FIG. 7D  shows a side, cutaway view of the de-linker assembly receiving the operating rod arm assembly; 
           [0046]      FIG. 7E  shows another side, cutaway view of the de-linker assembly as it is being pulled rearward by the operating rod arm assembly; 
           [0047]      FIG. 7F  shows yet another side, cutaway view of the de-linker assembly, as it is being released from the operating rod arm assembly; 
           [0048]      FIG. 8  shows a side view of the ammunition feed adapter and one embodiment of the forward firearms mount assembly according to the present invention; and 
           [0049]      FIG. 9  shows an ammunition feed adapter configured for use on a number of firearms as the barrels of the firearms become overheated. 
       
    
    
       [0050]    It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of disclosed ammunition feed adaptors and associated methods. It is appreciated that it is not possible to clearly show each element and aspect of every possible embodiment in a single figure, and as such, multiple figures are presented to separately illustrate the various details in greater clarity. Similarly, not every embodiment need accomplish all advantages or features of the present invention. Finally, the dimensions, tolerances and hardness of the materials used to construct the ammunition feed adapter described herein may vary due to the caliber and type of firearm. 
       DETAILED DESCRIPTION 
       [0051]    The invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims. 
         [0052]    Turning now to  FIG. 1  and  FIG. 2 , an ammunition feed adapter, generally indicated at  4 , may be provided with a main frame  10 , a cartridge lift follower body assembly  40 , a belt puller assembly  100 , a timing plate assembly  300 , an operating rod assembly  400 , a de-linker assembly  500  (See  FIG. 7A ), and a forward firearm mount assembly  600 . The adapter  4  may be manufactured so that one or more of the non-moving parts of the various assemblies are formed or molded as a single unit. Alternatively, as described herein, the various assemblies can be individually manufactured using standard tools or machines, the individual assemblies may then be fixedly or removably attached to the main frame in order to produce the present invention. The dimensions, tolerances and hardness of the materials used to construct the ammunition feed adapter described herein may vary due to the caliber and type of firearm. 
         [0053]    The ammunition feed adapter  4  is attached to the host firearm using the magazine well. The cartridge lift  40  fits into the magazine well as would a normal magazine used by the host firearm, with the magazine catch  52  securing the adapter into position. 
         [0054]    The operating rod assembly  400  attaches to the firearm&#39;s action mechanism, such as a bolt lever, which provides the mechanical energy needed for the operation of the ammunition feed adapter  4 . As the bolt is moved rearward, either manually or by discharge of ammunition in the firearm&#39;s chamber, the operating rod  404  pulls the de-linker rod  504 , rearward, towards the belt puller assembly  100 , where the rod  504  engages a cartridge  101 . The cartridge  101  is disengaged from the belt link and forced into the cartridge lift assembly  40  for introduction into the host firearm&#39;s firing mechanism. At the same time, the operating arm  404  acts on the timing plate  304  also moving it rearward. As a consequence of the rearward movement of the timing plate  304 , the belt puller arm  124  is pulled outwardly towards the timing plate assembly  300  which in turn moves the next cartridge into a loading position, i.e. resting against the cartridge stop  104 . Also, as the timing plate  304  is moved rearward, it acts on the cartridge lift outer arm  72  ultimately resulting in the cartridge  101  being inserted into the gun&#39;s chamber. 
         [0055]    Now turning to  FIG. 3A  and  FIG. 3B , the cartridge lift  40  includes a cartridge lift follower body  44  which is a rectangular box with a generally open top. Cartridge retainer lips  48  are attached to the top of the lift body  44  to help guide a cartridge into the firearm&#39;s chamber. The cartridge lift follower body  44  is shown with an arcuate slot  46  in the front of the lift body which allows a cartridge to pass during chambering. In addition, a channel  54  in the rear allows for bolt clearance during operation of a firearm. Finally, a magazine catch  52  is provided to allow the magazine latch of the host firearm to securely connect the ammunition feed adapter thereto. 
         [0056]    The cartridge lift follower  56 , embodied in  FIG. 3C , can be made out of square steel tubing with end caps  58   a,    58   b  extending beneath the follower  56 . The cartridge lift follower  56  has a longitudinal slot for receiving the cartridge support spring  60 . The cartridge support spring  60  is a length of flat spring designed to dampen the impact of a cartridge against the cartridge retainer lips  48  (See  FIG. 3B ) when it is lifted into place by the cartridge lift follower  56  prior to chambering. The support spring  60  is held in place by using a retainer pin  64  that extends through the cartridge lift follower body at one end thereof. The end  62  of the support spring  60  is bent so that the front of a cartridge remains elevated as it leaves the retainer lips  48  in order to facilitate chambering of the cartridge. A space  63 , between the end cap  58   a  and the bent end  62  of the support spring  60 , allows the spring to extend when compressed. 
         [0057]    To further lessen the impact of a cartridge against the retainer lips  48 , a capture link  68  is provided. Capture link  68  is attached to and suspended beneath the cartridge lift follower  56 . The capture link  68  can be made of steel rod bent to form an open-ended link that attaches to the lift body  56  via a hole  67  that is drilled laterally in the lower center portion thereof. The cartridge lift follower return spring  88  (See  FIG. 3A ) is connected to the follower arm  80 , holding the cartridge lift follower  56  at the bottom of the cartridge lift assembly  40 . The lift follower return spring  88  provides a downward force on the lift follower  56  when it is attached thereto via the capture link  68 . This force dampens the impact of a cartridge against the retainer lips  48  and also is responsible for the return of the lift follower  56  to the bottom of the cartridge lift assembly  40  at the end of each cycle. 
         [0058]    Now referencing  FIG. 3D  and  FIG. 3E , a top view of one embodiment of the cartridge lift arm  70  is provided. The cartridge lift arm  70  further comprises an axel  76  that connects an outer arm  72  to an inner arm  80 . The outer arm  72  is contacted by the timing plate arm  308 , forcing it backwards (discussed in more detail below). The backwards force is transferred along the axel to the inner arm which pushes the cartridge lift follower  56  in an upward direction. 
         [0059]    The axel  76  has an end  77   a  to which the outer arm  72  is attached thereto. The axel  76  also has a second end  77   b  having a smaller diameter, as compared to  77   a,  to which the inner arm  80  is attached. One way the inner arm may be attached to end  77   b  is by boring out a piece of rod so that it slips over the end  77   b,  set screw  84  is then used to secure inner arm  80  in the desired position. A coil spring  88  provides the energy required for the return of the inner arm to the bottom of the cartridge lift follower body  44 . The coil spring  88  is mounted to the main frame  10  (See  FIG. 1 ) at one end  89  and to the inner arm  80  at the other end  86 . 
         [0060]    Now turning to the belt puller assembly  100 .  FIG. 4A  shows one embodiment with belt tray  102  and sides  102   a,    102   b.  The sides  102   a  and  102   b  act as cartridge guides during operation of a host firearm. Side  102   a  has an arcuate slot  103  cut therein to allow the de-linker assembly  500  to act upon the linked cartridges. Similarly, side  102   b  has an opening  105  cut therein to allow exit of the de-linked cartridge from the belt puller assembly  100  into the cartridge lift follower body  44 . A cartridge stop  104  is also provided in order to hold the rear of a cartridge in alignment. Finally, the belt tray has at least on slot  106  formed on the floor of the tray which provides access and guidance for the belt puller teeth  144  (See  FIG. 4C ). 
         [0061]    Also shown is the mounting plate  108  which can be formed as part of the belt tray  102  or can otherwise be fixedly attached. The mounting plate  108  has a slot  109  located on the face thereof to allow the belt puller arm  124  to pass therethrough. The mounting plate  108  is used to attach the belt puller assembly  100  to the main frame  10  ( FIG. 1 ). Adjacent the mounting plate  108  is the belt puller guide  112 . The belt puller guide  112  can be made from a piece of flat metal bent at two ninety degree angles. The resulting three sides of the belt puller guide  112  and the back side of the mounting plate  108  define a compartment  113  containing the belt puller teeth guide spring arms  116  and a section of the belt puller arm  124  as described in further detail below (See  FIG. 4C ). 
         [0062]    Before describing the action of the belt puller assembly  100  in further detail,  FIG. 4B  provides one embodiment of the belt lock  176  which attaches to the belt puller tray. As shown, one way the belt lock  176  may be affixed to the tray is by using screws  198 . The side member of the belt lock frame  180  are descended along the outer surface of sides  102   a  and  102   b  ( FIG. 4A ), the screws are tightened, and finally the screws  198  are filed flush with the inner surfaces of sides  102   a  and  102   b.  The belt lock retainer rod  184  is mounted to the frame  180 . The retainer rod  184  can be made from a length of steel rod that has been turned on a lathe at one end to fit into the mounting hole  186   a  and drilled and threaded on the other end in order to be able to receive a mounting screw  185  inserted through mounting hole  186   b.    
         [0063]    In addition, attached to the belt lock retainer rod  184  is at least one retainer  188  or, more preferably, a set of retainers  188 . The retainers  188  are spaced along the rod at a width that keeps them from contacting the links of the ammunition belt and are also shaped to fit the intended cartridge with respect to said cartridge&#39;s diameter. At least one of the retainers  188  has a belt lock tab  189  which allows the retainers to be manually lifted in order to remove the ammunition belt from the belt puller assembly  100 . A spring  196  raps around the rod  184  and hooks to a retainer at one end and extends to the roof of the frame  180  at the other end thereby providing a constant downward force on the retainers  188 . 
         [0064]      FIGS. 4C through 4E  show more detailed cutaway, side views of the belt puller assembly  100 . Linked cartridges of an ammunition belt are loaded into the belt tray  102  by inserting the first cartridge  101  into belt lock  176  until it passes the retainers  188 . Pushing the ammunition belt into the belt lock  176  provides enough force to the generally curved back of the belt puller teeth  144  to force them downward. Once the cartridge  101  has cleared the tip of the teeth  144 , the teeth return to the “set position” as seen in  FIG. 4C . (The set position correlates with the host firearm&#39;s bolt being open.) The teeth  144  return to the set position because an upward force is applied to the base  142  of the teeth  144 , which is supplied by the spring  172  and the spring guide arms  116 . The spring  172  and guide arms  116  are secured to the belt puller guide  112  using pins and base plate  160 . In the set position, the retainers  188  and teeth  144  are positioned so that the cartridge  101  is locked into the belt puller assembly  100 . However, the ammunition belt can be removed by pressing down on the lock tab  189  and pulling the belt free from the belt puller assembly  100 . 
         [0065]    As seen in  FIG. 4D , when the host firearm&#39;s bolt is closed, the belt puller arm  124  moves in an outward direction  125  via the timing plate assembly  300  (See  FIGS. 5A and 5B ) and operating rod assembly  400  (See  FIG. 6 ), which are described in further detail below. The outward force pulls the cartridge  101  into the “load position” against the cartridge stop  104 . FIG.  5 B shows a cartridge  101  as it is being moved to the load position. As this is happening, the retainers  188  will be lifted, against the downward force of the belt lock spring  196  ( FIG. 4B ), by the second cartridge until the second cartridge passes. Once the second cartridge has cleared, the retainers  188  will return to the set position holding the ammunition belt in place. The first cartridge  101 , in the load position, is ready to be de-linked and enter the cartridge lift follower body  40 .  FIG. 4E  shows the belt puller arm  124  moving inward after the host weapon fires a bullet, with the teeth  144  dipping under the next cartridge on the cartridge belt. Contact between the generally curved back of teeth  144  and the next cartridge forces the guide arms  116  downward, compressing the spring  172 , and allowing the teeth  144  to pass underneath the cartridge. 
         [0066]    Firing of the host firearm results in a large amount of torque which is transferred to the puller arm  124 . To counter this force, a preferred embodiment of the invention will have a kickback stop  143  and an extended teeth base  142  which increase the friction through contacts made with the belt tray  102  and guide arms  116  in order to counter the force generated by the gun&#39;s recoil. 
         [0067]    The belt puller arm  124  can be made out of flat steel bar, or other suitable material, with at least one tooth  144  attached at one end. At the other end is attached a bearing that extends orthogonally from the puller arm  124  and engages the timing plate  304  ( FIG. 1B ). The guide arms  116  can be made out of similar material as the belt puller arm. FIG.  4 F(a) and  4 F(b) show one embodiment of the puller arm  124  and  FIG. 4G  shows one embodiment of the guide arms  116  of the present invention. As seen in FIGS.  4 F(a) and  4 F(b), said orthogonally extended bearing is comprised of a bearing ring  136  and roller bolt  132 . Also, in one embodiment, the puller arm  124  includes at least two puller teeth  144  that are attached in a hinge-like fashion. 
         [0068]    Where the teeth  144  are attached, the puller arm  124  is formed into a threaded hinge  130  to receive a headless screw  128 . Extending downward from the base of the teeth  144  is a connector link  152  where the screw  128  passes through to connect the teeth  144  and the arm  124 . As seen in  FIG. 4G , the spring guide arms  116  have a slot  118  therein to accommodate the puller arm  124  when assembled. In other embodiments, the belt puller assembly  100  may include a rotating gear that would function is a manner similar to the assembly with puller arm  124  described above except that a gear having teeth to advance the belt would rotate to advance each round. 
         [0069]    Referring now to  FIG. 5A and 5B , the timing plate assembly  300 , in connection with the operating rod assembly  400  ( FIG. 6 ), couples the movement of the belt puller tray assembly  100  with the firing of the host firearm. The timing plate assembly  300  includes two basic parts, the timing plate guide  312  and the timing plate  304 . The timing plate guide  312  is mounted to the main frame  10 , or alternatively, formed as part of the frame itself. The plate  304  is positioned above the guide  312  and connected thereto using bearings  134  mounted on plate  304  (such as roller bolts  132  and roller bearing rings  136  described above) and which extend through the bi-lateral slots  314  in the guide  312 . The diagonal slot  306  connects the plate  304  to the belt puller arm  124  by extending the bearing  133 , which is attached to the arm  124 , through said diagonal slot. The timing plate assembly  300  further comprises a space  316  in the guide  312  wherein the belt puller arm  124  is positioned in order to guide its movements, a timing plate arm  308  that is formed or attached to the timing plate  304 , and a timing plate cam  316  that is formed or attached to the guide mount  312 . 
         [0070]    The timing plate  304  is propelled in the direction indicated by arrow  200  when the timing plate arm  308  receives catch pin  412 , of the operating rod assembly  400 , as the host firearm is manually charged or a cartridge is discharged. Moving the timing plate in a backwards direction forces the belt puller arm in the direction indicated by arrow  212  by virtue of said arms being connected to the diagonal slot  306  and its travel therein. The plate&#39;s  304  movement is guided by the slots  314  in the timing plate guide mount  312 . When the plate is in the position seen in  FIG. 5A  the belt puller teeth  144  are in the set position and the host firearm&#39;s bolt is open. Closing of the host firearm&#39;s action will lead to the timing plate  304  being moved in a forward direction indicated by arrow  202  until it reaches the full front position and resulting in the belt puller teeth  144  moving the next cartridge into the load position. The cycle is then repeated. 
         [0071]    Now turning to  FIG. 6 , a side and top view of one embodiment of the operating rod assembly  400  is provided which shows the operating rod arm  404  with a mounting attachment  408 , catch pin  412  and catch arm  416  attached thereto. The operating rod arm  404  is connected to the host firearm&#39;s action mechanism, such as a bolt, using the mounting attachment  408 . The mounting attachment  408  can be made to accommodate a variety of firearms. One embodiment uses a set screw as a means of attaching to the cocking lever of a firearm. Another embodiment has a mount that fits over the cocking lever, with a slide lock that is rotated downward, keeping the operating rod arm  404  in alignment. 
         [0072]    The operating rod assembly  400  coordinates the operation of the ammunition feed adaptor as follows. The catch arm  416  contacts the back of the timing plate arm  308  ( FIG. 5A ) when the host firearm&#39;s bolt closes in order to drive the timing plate  304  forward. The catch pin  412  contacts the front of the timing plate arm  308  after the host firearm is fired, driving the timing plate  304  backwards. Also, the catch pin  412  is received by the de-linker latch  572 , and coordinates the action of the de-linker assembly  500  as described below. The spacing of these contact points is key to the operation of the ammunition feed adapter with a given weapon. The difference in spacing between the contact points on a particular ammunition feed adapter allows for precisely timed and coordinated function with a variety of host weapons. 
         [0073]    Turning now to  FIG. 7A  and  FIG. 7B , a cutaway side and top view, respectively, of one embodiment of the de-linker assembly  500  is shown mounted on main frame  10 . The de-linker rod  504  extends from the base  508  towards and through the de-linker rod guide  544 . The guide  544  aligns the end of the rod  504  for entry into the belt puller assembly  100  when the de-linker return spring  540  is in the fully relaxed position. When in the fully relaxed position the, the base  508  rest against the de-linker return stop  560 . 
         [0074]    At the other end, the de-linker rod  504  is attached to the base  508 . In one embodiment of the present invention the main frame  10  is made out of square steel tubing and the base  508  is shaped and sized such that it is able to slide freely within the frame  10  without becoming bound. The base  508  has a ridge extending upward that fits into a longitudinal slot cut into the top of the main frame  10  in order to keep the de-linker rod  504  aligned with respect to the frame  10  while in operation. 
         [0075]    Attached to the ridge extending through the main frame  10  is a latch frame  576 . The latch frame  576  extends over the external surface of the main frame  10  and provides an attachment point for the de-linker latch arms  572 ,  573 . The dual arms  572 , 573  can be formed from one piece of material and are attached with a means which allows them to freely rotate up and down. However, the default position is parallel with the main frame  10  which is maintained by applying a downward force using a spring  580  that is attached to the latch frame  576  at one and the latch arms  572 ,  573  at the other. Both latch arms  572  and  573  are made to have a generally curved shape, with arm  573  having a slightly greater length than arm  572 . Finally, arm  572  has a latch  574  that is designed to receive the catch pin  412  of the operating rod arm  404 . 
         [0076]    As seen in  FIG. 7C , one embodiment of the de-linker rod  504  is bored on one end to accept the cartridge buffer  520  and buffer spring  516 . The cartridge buffer has a flat cut  521  made thereon to accommodate a pin  524  which is inserted through a hole drilled in the de-linker rod  504 . Additionally, the cartridge buffer head  522  is counter bored to form a guide which, upon impact, aligns the cartridge for entry into the lift body assembly  40 . 
         [0077]    Now turning to  FIG. 7D-7F , the operation of the de-linker assembly  500  is coordinated by the function of the operating rod arm  404 . The operating rod arm  404  is attached to the host firearm&#39;s action  702  which provides the mechanical force for the entire operation of the ammunition feed adapter. When the action is moved in the direction indicated by arrow  220 , the catch pin  412  impacts the curved surface of latch arm  572  and forces the arms  572 ,  573  upward until the pin  412  is received in slot  574 , connecting the de-linker assembly with the operating rod assembly. 
         [0078]    The energy generated from the discharge of a cartridge causes the firearm&#39;s action  702  to open. This energy is transferred to the de-linker system through the operating arm  404 , forcing the de-linker rod  504  rearward until it engages the next cartridge, driving the cartridge into the cartridge lift follower body. Finally, when the latch arm  573  contacts the timing cam  316  on the timing plate guide mount, the arms  572 ,  573  are again forced upward, the catch pin  412  is released, the de-linker return spring  540  is allowed to decompress, which forces the base to return to rest against the de-linker return stop  560 . The cycle is then repeated. 
         [0079]    Now referring to  FIG. 8 , a side view of one embodiment of the forward firearm mount assembly  600  is provided. To increase the stability of the ammunition feed adapter when mounted to a firearm, an optional forward firearm mount assembly  600  may be used. The firearm mount adapter  600  has an internal section  604  that extends into the main frame  10  of the ammunition feed adapter and is held in place by inserting a quick disconnect pin  612  through aligned holes in the frame  10  and internal section  604 . An end cap  608 , which sits against the outer edge of the frame  10 , aids in aligning the two holes. Also, the end cap is configured to receive a number of mounts  620  which are designed for specific use with various firearms. The head  624  of a generic mount  620  sits within a recessed portion of the firearm mount adapter base  646  which is affixed to the host firearm at a given location, for example the barrel. This allows the adapter to be released and mounted into the magazine of the firearm in a few seconds. Once mounted in the magazine, the adapter allows the firearm to be belt-fed rather than relying on magazines. 
         [0080]    Turning now to  FIG. 9 , an ammunition feed adapter is shown configured for use on a number of firearms. The adapter  4  may include a collapsible tripod  700  if desired, to allow the host firearm to be used in a manner similar to a SAW. 
         [0081]    One concern with automatic firearms is the considerable heat which can be generated. Firing hundreds of rounds through a barrel in a very short period of time can cause the barrel to overheat. The heat of the barrel can also cause the ammunition rounds to fire prematurely, often called “cooking off.” Because many lighter firearms were not designed to handle sustained firing for prolonged periods of time, leaving a firearm in full automatic fire mode can overheat the barrel in as little as a minute. One advantage of the present invention is that the adapter  4  can be quickly changed out of one firearm and into another. 
         [0082]    Thus,  FIG. 9  shows the adapter  4  mounted in a generic magazine-fed weapon. A typical assault rifle can fire up to 600 rounds per minute. However, such a volume will cause the barrel to quickly heat up. Rather than waiting for the barrel to cool back down before firing, the rifle  720  is simply removed from the adapter  4  and a new rifle  730  is attached in its place. The second rifle  730  can be used for firing while the first rifle cools down. Multiple rifles can be used with the adapter  4  to maintain automatic fire for prolonged periods of time. The entire process of changing the rifles  720 ,  730 , etc., takes only moments longer than changing a magazine in the rifles individually. One soldier can be changing rifles while another is attaching belts together to provide a continual supply of ammunition. 
         [0083]    Additionally, unlike a SAW, if the soldiers are forced to evacuate their position, each can take one of the rifles and those which are not being used with the adapter  4  can be readied for use by simply inserting a magazine. 
         [0084]    One major advantage of the present invention is that it will allow a squad of soldiers to have multiple rifles which are capable of use as belt-fed automatic firearms. This dramatically lessens the abilities of enemies to cripple the squad by initially targeting the SAW. It also allows smaller, lighter firearms to be used for automatic fire from a number of locations—allowing the defensive perimeter to change much more rapidly. 
         [0085]    There is thus disclosed an ammunition feed adapter that can convert a magazine-fed gun into a belt-fed gun. It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims.

Technology Classification (CPC): 5