Ambidextrous bottom belt feed and box feed firearm

Abstract

A belt feed mechanism for a firearm can be oriented with a feed side (or ejection side) of the mechanism on either the left or right side of the firearm when mounted to the firearm. The belt feed mechanism is configured to slide out to the feed side of the mechanism for loading and push back in toward the ejection side of the mechanism to feed ammunition from a disintegrating ammunition belt into the firearm. The belt feed mechanism includes a male ammunition box dovetail extending downward from a cradle of the mechanism configured to insert into a female recess in an ammunition box to hang the ammunition box from the belt feed mechanism.

What is claimed is: 
     
         1 . A belt feed mechanism for a firearm configured to receive a disintegrating ammunition belt comprising links and rounds of ammunition at a feed side of the belt feed mechanism and eject the links at an ejection side of the belt feed mechanism, said belt feed mechanism comprising:
 a feed paddle configured to advance the disintegrating ammunition belt into the belt feed mechanism from the feed side of the belt feed mechanism as the feed paddle rotates about a longitudinal axis of the belt feed mechanism;   a paddle spring configured to store energy, bias the feed paddle to rotate, and rotate the feed paddle when the feed paddle is able to rotate; and   a drive pawl wheel configured to provide energy to the paddle spring for storage by the paddle spring.   
     
     
         2 . The belt feed mechanism of  claim 1 , wherein:
 the drive pawl wheel is configured to be rotated about the longitudinal axis of the belt feed mechanism by a bolt carrier group of the firearm when the firearm cycles;   the drive pawl wheel interlocks with the feed paddle such that the drive pawl wheel and feed paddle are limited to a predetermined limit of angular travel relative to one another; and   the paddle spring is pre-tensioned such that the paddle spring provides a predetermined minimum amount of bias pressure to the feed paddle relative to the drive pawl wheel and the drive pawl wheel is either:   held at o degrees of rotation relative to the feed paddle prior to being advanced to the predetermined limit of angular travel relative to the feed paddle by the bolt carrier group of the firearm when the bolt carrier group of the firearm moves from a rear position of the bolt carrier group to a forward position of the bolt carrier group; or   held at the predetermined limit of angular travel relative to the feed paddle prior to being advanced to o degrees relative to the feed paddle by the bolt carrier group of the firearm when the bolt carrier group of the firearm moves from the rear position of the bolt carrier group to the forward position of the bolt carrier group.   
     
     
         3 . The belt feed mechanism of  claim 1 , wherein:
 the drive pawl wheel and the feed paddle are configured to rotate in the same direction about the longitudinal axis of the belt feed mechanism as the firearm is cycled;   the drive pawl wheel comprises a plurality of teeth extending outwardly from the longitudinal axis of the belt feed mechanism; and   the belt feed mechanism further comprises an anti reversing latch configured to sequentially engage each tooth of the teeth the drive pawl wheel and limit rotation of the drive pawl wheel opposite the feed paddle as the firearm is cycled.   
     
     
         4 . The belt feed mechanism of  claim 1 , wherein:
 the belt feed mechanism further comprises a bump pawl configured to contact the bolt carrier group of the firearm as the bolt carrier group of the firearm moves forward and translate forward movement of the bolt carrier group into rotational movement of the drive pawl wheel by contacting a tooth of the drive pawl wheel as the bump pawl is moved out of the path of the bolt carrier group by the bolt carrier group.   
     
     
         5 . The belt feed mechanism of  claim 1 , wherein:
 the paddle spring is a torsion spring configured to engage the drive pawl wheel at a first end of the torsion spring and the feed paddle at a second end of the torsion spring opposite the first end of the torsion spring;   the belt feed mechanism further comprises a round stop at the ejection side of the belt feed mechanism;   the feed paddle is prevented from rotating by contact of an ammunition round of the disintegrating ammunition belt with a round stop of the belt feed mechanism or a bolt carrier group of the firearm;   the round stop is integral with a dust cover of the belt feed mechanism; and   the belt feed mechanism further comprises a feed port at the feed side of the belt feed mechanism.   
     
     
         6 . The belt feed mechanism of  claim 1 , wherein:
 the feed paddle comprises a plurality of teeth extending outwardly from the longitudinal axis of the belt feed mechanism, each tooth comprising an ammunition round portion and a link portion;   the teeth of the feed paddle sequentially engage sequential rounds of ammunition in the disintegrating ammunition belt as the firearm cycles to pull the disintegrating ammunition belt into the feed side of the belt feed mechanism;   the feed paddle advances rotationally about the longitudinal axis of the belt feed mechanism as a bolt carrier group of the firearm moves from a front position to a rear position of the bolt carrier group; and   as the feed paddle advances, a tooth of the plurality of teeth of the feed paddle engaging a link of the disintegrating ammunition belt separated from the disintegrating ammunition belt by the bolt carrier group removing a round of ammunition from the disintegrating ammunition belt ejects the separated link at the ejection side of the of the belt feed mechanism as the bolt carrier group moves to the rear position of the bolt carrier group.   
     
     
         7 . The belt feed mechanism of  claim 1 , wherein:
 the drive pawl wheel is configured to be rotated about the longitudinal axis of the belt feed mechanism by a bolt carrier group of the firearm when the firearm cycles;   the drive pawl wheel interlocks with the feed paddle such that the drive pawl wheel and feed paddle are limited to a predetermined limit of angular travel relative to one another;   the paddle spring is pre-tensioned such that the paddle spring provides a predetermined minimum amount of rotational bias pressure to the feed paddle relative to the drive pawl wheel;   the belt feed mechanism further comprises a main axle configured to extend along the longitudinal axis of the belt feed mechanism, wherein the drive pawl wheel is connected to and supports the main axle when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a needle bearing between the feed paddle and the main axle when the belt feed mechanism is assembled such that the feed paddle is supported by the needle bearing and the main axle and feed paddle rotate about the longitudinal axis of the belt feed mechanism independently of one another.   
     
     
         8 . The belt feed mechanism of  claim 1 , wherein:
 a cradle configured to mount to a receiver of the firearm via a front captured pin and a rear captured pin;   a housing configured to slidingly engage the cradle, wherein the housing has a loading position and a feed position relative to the cradle, said loading position being slid partially out of the cradle away from the firearm toward the feed side of the belt feed mechanism and said feed position being slid into the cradle toward the ejection side of the belt feed mechanism;   a housing spring configured to bias the housing toward the loading position; and   a feed mechanism plunger configured to extend from the housing into a corresponding feed mechanism plunger hole in the cradle when the housing is in the feed position, locking the housing into the feed position, and to extend from the housing into a corresponding groove in the cradle when the housing is in the loading position; and   a release button mounted on the cradle, said release button configured to remove the feed mechanism plunger from the feed mechanism plunger hole in the cradle when actuated such that the housing is released and the housing spring moves the housing from the feed position to the loading position.   
     
     
         9 . The belt feed mechanism of  claim 1 , wherein:
 the feed paddle is a first feed paddle;   the paddle spring is a first paddle spring;   the drive pawl wheel is a first drive pawl wheel;   the first drive pawl wheel is configured to be rotated about the longitudinal axis of the belt feed mechanism by a bolt carrier group of the firearm when the firearm cycles;   the first drive pawl wheel interlocks with the feed paddle such that the first drive pawl wheel and feed paddle are limited to a predetermined limit of angular travel relative to one another;   the first paddle spring is pre-tensioned such that the first paddle spring provides a predetermined minimum amount of rotational bias pressure to the first feed paddle relative to the drive pawl wheel;   the belt feed mechanism further comprises a main axle configured to extend along the longitudinal axis of the belt feed mechanism, wherein the first drive pawl wheel is connected to the main axle and supports the main axle when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a first needle bearing between the first feed paddle and the main axle when the belt feed mechanism is assembled such that the first feed paddle is supported by the first needle bearing and the main axle and first feed paddle rotate about the longitudinal axis of the belt feed mechanism independently of one another;   the belt feed mechanism further comprises a second drive pawl wheel connected to the main axle longitudinally opposite the first drive pawl wheel when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a second feed paddle;   the belt feed mechanism further comprises a second paddle spring connected between the second drive pawl and the second feed paddle to rotationally bias the second feed paddle relative to the second drive pawl;   the belt feed mechanism further comprises a second needle bearing between the second feed paddle and the main axle when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a cradle configured to mount to a receiver of the firearm via a forward captured pin and a rear captured pin; and   the cradle is configured to mount to the receiver with the front captured pin closer to a muzzle of the firearm than the rear captured pin such that the feed side of the belt feed mechanism is on a left side of the firearm or with the rear captured pin closer to the muzzle of the firearm that the front captured pin such that the feed side of the belt feed mechanism is on right side of the firearm.   
     
     
         10 . The belt feed mechanism of  claim 1 , wherein:
 the belt feed mechanism further comprises a cradle configured to support the feed paddle, paddle spring, and drive pawl wheel and to mount to a receiver of the firearm via a front captured pin and a rear captured pin; and   the belt feed mechanism further comprises an ammunition box dovetail, said ammunition box dovetail extending downwardly from the cradle when the belt feed mechanism is assembled on the firearm and the firearm is in an upright position;   the ammunition box dovetail is wider at a bottom of the ammunition box dovetail than at a top of the ammunition box dovetail;   an end of the ammunition box dovetail at the feed side of the belt feed mechanism extends further laterally at the bottom of the ammunition box dovetail than at the top of the ammunition box dovetail; and   the ammunition box dovetail comprises at least one recess configured to receive a detent ball of an ammunition box slid onto the ammunition box dovetail to retain the ammunition box onto the ammunition box dovetail.   
     
     
         11 . A firearm comprising:
 a barrel;   a bolt carrier group configured to load a round of ammunition from a belt feed mechanism into the barrel and fire the round of ammunition from the barrel when actuated;   a fire control group configured to selectively actuate the bolt carrier group;   a receiver configured to support the barrel, the fire control group, and the bolt carrier group; and   a belt feed mechanism configured to receive a disintegrating ammunition belt comprising links and rounds of ammunition at a feed side of the belt feed mechanism and eject the links at an ejection side of the belt feed mechanism, said belt feed mechanism comprising:   a feed paddle configured to advance the disintegrating ammunition belt into the belt feed mechanism from the feed side of the belt feed mechanism as the feed paddle rotates about a longitudinal axis of the belt feed mechanism;   a paddle spring configured to store energy, bias the feed paddle to rotate, and rotate the feed paddle when the feed paddle is able to rotate; and   a drive pawl wheel configured to provide energy to the paddle spring for storage by the paddle spring.   
     
     
         12 . The firearm of  claim 11 , wherein:
 the drive pawl wheel is configured to be rotated about the longitudinal axis of the belt feed mechanism by a bolt carrier group of the firearm when the firearm cycles;   the drive pawl wheel interlocks with the feed paddle such that the drive pawl wheel and feed paddle are limited to a predetermined limit of angular travel relative to one another; and   the paddle spring is pre-tensioned such that the paddle spring provides a predetermined minimum amount of bias pressure to the feed paddle relative to the drive pawl wheel and the drive pawl wheel is either:
 held at o degrees of rotation relative to the feed paddle prior to being advanced to the predetermined limit of angular travel relative to the feed paddle by the bolt carrier group of the firearm when the bolt carrier group of the firearm moves from a rear position of the bolt carrier group to a forward position of the bolt carrier group; or 
 held at the predetermined limit of angular travel relative to the feed paddle prior to being advanced to o degrees relative to the feed paddle by the bolt carrier group of the firearm when the bolt carrier group of the firearm moves from the rear position of the bolt carrier group to the forward position of the bolt carrier group. 
   
     
     
         13 . The firearm of  claim 11 , wherein:
 the drive pawl wheel and the feed paddle are configured to rotate in the same direction about the longitudinal axis of the belt feed mechanism as the firearm is cycled;   the drive pawl wheel comprises a plurality of teeth extending outwardly from the longitudinal axis of the belt feed mechanism; and   the belt feed mechanism further comprises an anti reversing latch configured to sequentially engage each tooth of the teeth the drive pawl wheel and limit rotation of the drive pawl wheel opposite the feed paddle as the firearm is cycled.   
     
     
         14 . The firearm of  claim 11 , wherein:
 the belt feed mechanism further comprises a bump pawl configured to contact the bolt carrier group of the firearm as the bolt carrier group of the firearm moves forward and translate forward movement of the bolt carrier group into rotational movement of the drive pawl wheel by contacting a tooth of the drive pawl wheel as the bump pawl is moved out of the path of the bolt carrier group by the bolt carrier group.   
     
     
         15 . The firearm of  claim 11 , wherein:
 the paddle spring is a torsion spring configured to engage the drive pawl wheel at a first end of the torsion spring and the feed paddle at a second end of the torsion spring opposite the first end of the torsion spring;   the belt feed mechanism further comprises a round stop at the ejection side of the belt feed mechanism;   the feed paddle is prevented from rotating by contact of an ammunition round of the disintegrating ammunition belt with a round stop of the belt feed mechanism or a bolt carrier group of the firearm;   the round stop is integral with a dust cover of the belt feed mechanism; and   the belt feed mechanism further comprises a feed port at the feed side of the belt feed mechanism.   
     
     
         16 . The firearm of  claim 11 , wherein:
 the feed paddle comprises a plurality of teeth extending outwardly from the longitudinal axis of the belt feed mechanism, each tooth comprising an ammunition round portion and a link portion;   the teeth of the feed paddle sequentially engage sequential rounds of ammunition in the disintegrating ammunition belt as the firearm cycles to pull the disintegrating ammunition belt into the feed side of the belt feed mechanism;   the feed paddle advances rotationally about the longitudinal axis of the belt feed mechanism as a bolt carrier group of the firearm moves from a front position to a rear position of the bolt carrier group; and   as the feed paddle advances, a tooth of the plurality of teeth of the feed paddle engaging a link of the disintegrating ammunition belt separated from the disintegrating ammunition belt by the bolt carrier group removing a round of ammunition from the disintegrating ammunition belt ejects the separated link at the ejection side of the of the belt feed mechanism as the bolt carrier group moves to the rear position of the bolt carrier group.   
     
     
         17 . The firearm of  claim 11 , wherein:
 the drive pawl wheel is configured to be rotated about the longitudinal axis of the belt feed mechanism by a bolt carrier group of the firearm when the firearm cycles;   the drive pawl wheel interlocks with the feed paddle such that the drive pawl wheel and feed paddle are limited to a predetermined limit of angular travel relative to one another;   the paddle spring is pre-tensioned such that the paddle spring provides a predetermined minimum amount of rotational bias pressure to the feed paddle relative to the drive pawl wheel;   the belt feed mechanism further comprises a main axle configured to extend along the longitudinal axis of the belt feed mechanism, wherein the drive pawl wheel is connected to and supports the main axle when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a needle bearing between the feed paddle and the main axle when the belt feed mechanism is assembled such that the feed paddle is supported by the needle bearing and the main axle and feed paddle rotate about the longitudinal axis of the belt feed mechanism independently of one another.   
     
     
         18 . The firearm of  claim 11 , wherein:
 a cradle configured to mount to a receiver of the firearm via a front captured pin and a rear captured pin;   a housing configured to slidingly engage the cradle, wherein the housing has a loading position and a feed position relative to the cradle, said loading position being slid partially out of the cradle away from the firearm toward the feed side of the belt feed mechanism and said feed position being slid into the cradle toward the ejection side of the belt feed mechanism;   a housing spring configured to bias the housing toward the loading position; and   a feed mechanism plunger configured to extend from the housing into a corresponding feed mechanism plunger hole in the cradle when the housing is in the feed position, locking the housing into the feed position, and to extend from the housing into a corresponding groove in the cradle when the housing is in the loading position; and   a release button mounted on the cradle, said release button configured to remove the feed mechanism plunger from the feed mechanism plunger hole in the cradle when actuated such that the housing is released and the housing spring moves the housing from the feed position to the loading position.   
     
     
         19 . The firearm of  claim 11 , wherein:
 the feed paddle is a first feed paddle;   the paddle spring is a first paddle spring;   the drive pawl wheel is a first drive pawl wheel;   the first drive pawl wheel is configured to be rotated about the longitudinal axis of the belt feed mechanism by a bolt carrier group of the firearm when the firearm cycles;   the first drive pawl wheel interlocks with the feed paddle such that the first drive pawl wheel and feed paddle are limited to a predetermined limit of angular travel relative to one another;   the first paddle spring is pre-tensioned such that the first paddle spring provides a predetermined minimum amount of rotational bias pressure to the first feed paddle relative to the drive pawl wheel;   the belt feed mechanism further comprises a main axle configured to extend along the longitudinal axis of the belt feed mechanism, wherein the first drive pawl wheel is connected to the main axle and supports the main axle when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a first needle bearing between the first feed paddle and the main axle when the belt feed mechanism is assembled such that the first feed paddle is supported by the first needle bearing and the main axle and first feed paddle rotate about the longitudinal axis of the belt feed mechanism independently of one another;   the belt feed mechanism further comprises a second drive pawl wheel connected to the main axle longitudinally opposite the first drive pawl wheel when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a second feed paddle;   the belt feed mechanism further comprises a second paddle spring connected between the second drive pawl and the second feed paddle to rotationally bias the second feed paddle relative to the second drive pawl;   the belt feed mechanism further comprises a second needle bearing between the second feed paddle and the main axle when the belt feed mechanism is assembled;   the belt feed mechanism further comprises a cradle configured to mount to a receiver of the firearm via a forward captured pin and a rear captured pin; and   the cradle is configured to mount to the receiver with the front captured pin closer to a muzzle of the firearm than the rear captured pin such that the feed side of the belt feed mechanism is on a left side of the firearm or with the rear captured pin closer to the muzzle of the firearm that the front captured pin such that the feed side of the belt feed mechanism is on right side of the firearm.   
     
     
         20 . The firearm of  claim 11 , wherein:
 the belt feed mechanism further comprises a cradle configured to support the feed paddle, paddle spring, and drive pawl wheel and to mount to a receiver of the firearm via a front captured pin and a rear captured pin; and   the belt feed mechanism further comprises an ammunition box dovetail, said ammunition box dovetail extending downwardly from the cradle when the belt feed mechanism is assembled on the firearm and the firearm is in an upright position;   the ammunition box dovetail is wider at a bottom of the ammunition box dovetail than at a top of the ammunition box dovetail;   an end of the ammunition box dovetail at the feed side of the belt feed mechanism extends further laterally at the bottom of the ammunition box dovetail than at the top of the ammunition box dovetail;   the ammunition box dovetail comprises at least one recess configured to receive a detent ball of an ammunition box slid onto the ammunition box dovetail to retain the ammunition box onto the ammunition box dovetail; and   the firearm further comprises the ammunition box.