Firearm magazine with round counter

Abstract

A round-counting magazine may include a housing, the housing having a proximal end and a distal end. It may further include a follower having at least one magnet, a plurality of indentations formed in a first channel on a first side of the housing, wherein each indentation comprises a magnetic sensor, and wherein the first channel is positioned adjacent a path of the at least one magnet when the follower moves along a length of the housing. The magazine may further include at least one side cover positioned over the first channel and thereby protecting the magnetic sensors. A floor plate assembly on a bottom of the magazine may include a floor plate including a receptacle and a lock plate, where the receptable is shaped and sized to receive at least one power source and at least a portion of the lock plate.

What is claimed is: 
     
         1 . A magazine for a firearm, comprising:
 a housing, the housing having a proximal end and a distal end;   a follower having at least one magnet;   a plurality of indentations formed in a first channel on a first side of the housing, wherein each indentation of the plurality of indentations comprises a magnetic sensor, and wherein the first channel is positioned adjacent a path of the at least one magnet when the follower moves along a length of the housing;   at least one side cover positioned on at least one side of the housing, including at least a first side cover positioned on the first side of the housing, and wherein the plurality of indentations comprising the magnetic sensors are positioned between the first side cover and a bottom of the first channel;   a floor plate assembly positioned at the distal end of the housing, wherein the floor plate assembly comprises:
 a floor plate, wherein at least a portion of the floor plate is positioned below an opening in the distal end of the housing, and wherein the floor plate comprises a receptacle; and 
 a lock plate, and wherein the receptacle is shaped and sized to receive at least one power source and at least a portion of the lock plate. 
   
     
     
         2 . The magazine of  claim 1 , wherein the floor plate comprises a first rail positioned around at least a portion of an outer circumference of the floor plate, and wherein the floor plate assembly further comprises:
 a floor plate retainer having a second rail and a third rail, wherein the second rail is configured to interface with the first rail of the floor plate, and wherein the third rail is positioned proximal to the second rail and is shaped and sized to interface with a corresponding rail or groove at the distal end of the housing.   
     
     
         3 . The magazine of  claim 2 , wherein:
 the floor plate comprises:
 a body, 
 a rim, wherein the rim is positioned proximal to the first rail and is arranged around a proximal opening of a receptacle, 
 a through hole positioned at or near one end of the body; 
   the floor plate retainer comprises a screw hole; and   the floor plate assembly further comprises a retaining screw, wherein at least a portion of the retaining screw is shaped and sized to pass through the through hole and the screw hole to secure the floor plate to the floor plate retainer.   
     
     
         4 . The magazine of  claim 1 , wherein:
 the floor plate comprises a vertical portion, wherein at least a portion of the vertical portion extends above the opening in the distal end of the housing;   the lock plate comprises a body, an extension extending proximally from one end of the body, and a plurality of protrusions extending distally from the body, the extension having a recess that is shaped and sized to receive the vertical portion of the floor plate; and   the receptacle comprises a plurality of ribs arranged at or near a proximal end of the receptacle;   and wherein one or more of the plurality of protrusions are configured to abut one or more of the plurality of ribs.   
     
     
         5 . The magazine of  claim 1 , further comprising:
 a recess intersecting the first channel, wherein the recess extends along the first side of the housing between the first channel and one of a fore-end and an aft-end of the first side of the housing;   wherein the first side cover comprises:
 a first elongated section extending from substantially the proximal end to substantially the distal end of the housing, wherein the first elongated section is arranged over or partially within the first channel comprising the plurality of indentations and magnetic sensors; and 
 a second elongated section, wherein the second elongated section extends from the first elongated section towards one of the fore-end and the aft-end of the first side of the housing, and wherein the second elongated section is arranged over or partially within the recess. 
   
     
     
         6 . The magazine of  claim 5 , wherein each of the first and the second elongated sections comprises:
 a flat or substantially flat portion configured to remain flush against the first side of the housing; and   an arm portion extending at an angle with respect to a corresponding flat or substantially flat portion;   and wherein at least one arm portion of the first and the second elongated sections partially overlaps a second, different side of the housing.   
     
     
         7 . The magazine of  claim 5 , further comprising:
 at least one circuit board; and   one or more electrical bus plates for coupling the at least one circuit board to the plurality of magnetic sensors and the at least one power source.   
     
     
         8 . The magazine of  claim 7 , wherein the one or more electrical bus plates comprises:
 a first electrical bus plate substantially positioned within the floor plate assembly, wherein at least a portion of the first electrical bus plate extends above the opening in the distal end of the housing; and   a second electrical bus plate coupled to one or more of the plurality of magnetic sensors and the at least one circuit board;   wherein the at least one power source is directly coupled to the first electrical bus plate;   and wherein the first and the second electrical bus plates are configured to directly or inductively exchange power.   
     
     
         9 . The magazine of  claim 8 , wherein at least a portion of the second electrical bus plate is positioned adjacent, or within, the first channel and the recess on the first side of the housing. 
     
     
         10 . The magazine of  claim 1 , wherein the at least one power source comprises a battery inserted through a capped opening at one of a fore-end or an aft-end of the floor plate. 
     
     
         11 . A magazine for a firearm, comprising:
 a housing, the housing having a proximal end and a distal end;   a follower;   a plurality of indentations formed in a first channel on a first side of the housing, wherein each indentation of the plurality of indentations is shaped and sized to receive a magnetic sensor;   a first side cover positioned on a first side of the housing, wherein the plurality of indentations comprising magnetic sensors are positioned between a bottom of the first channel and the first side cover;   a second side cover comprising a proximal end and a distal end, the second side cover positioned on one of a front side or a rear side of the housing, wherein the second side cover comprises a second channel extending along at least a portion of a length of the second side cover;   a circuit board;   a floor plate assembly positioned at the distal end of the housing, wherein the floor plate assembly comprises:
 a floor plate having a horizontal portion and a vertical portion, wherein the vertical portion is positioned at one end of the horizontal portion and extends proximally to the horizontal portion; 
 a lock plate, wherein at least a portion of the lock plate extends through the floor plate; 
   wherein the vertical portion of the floor plate is configured to interface with the distal end of the second side cover;   and wherein at least a portion of the circuit board is positioned in a gap between the vertical portion of the floor plate and one of the front or the rear side of the housing.   
     
     
         12 . The magazine of  claim 11 , wherein the circuit board comprises a first electrical bus plate positioned adjacent one or more of the horizontal portion of the floor plate and the lock plate, and a second electrical bus plate, and wherein at least a portion of the second electrical bus plate is arranged in the gap between the vertical portion of the floor plate and one of the front or rear side of the housing. 
     
     
         13 . The magazine of  claim 12 , wherein the circuit board is electrically coupled to an NFC antenna, the NFC antenna configured to communicate round count information with another NFC antenna positioned in a magazine well of a firearm. 
     
     
         14 . The magazine of  claim 13 , wherein at least a portion of the lock plate protrudes through an opening in the first electrical bus plate, the first electrical bus plate further comprising:
 one or more receptacles for receiving one or more batteries, wherein the one or more receptacles are mounted on a distal face of the first electrical bus plate.   
     
     
         15 . The magazine of  claim 11 , wherein the second side cover comprises one or more notches or grooves positioned on one or more sides of the second channel, wherein the one or more notches or grooves are shaped and sized to interface with corresponding notches or grooves positioned along one of the front or the rear side of the housing. 
     
     
         16 . The magazine of  claim 11 , wherein at least a portion of the lock plate protrudes through a tapered opening in the floor plate. 
     
     
         17 . A round-counting magazine comprising:
 a housing configured to hold a stack of two or more cartridges and having a feed end opposite to a distal end, and a front end opposite to a rear end;   an end plate slidingly coupled to the distal end of the housing;   a follower slidingly arranged within the magazine and biased to feed the two or more cartridges toward the feed end of the housing;   a channel running along a first side of the housing from substantially the feed end of housing to substantially the distal end of the housing, the channel aligned with a path traversed by one or more magnets of the follower;   a recess intersecting the channel and running along the first side of the housing between the channel and a rear end of the housing;   a plurality of magnetic sensors arranged along the first channel;   a first electrical bus arranged in the second channel and configured to inductively draw power from a magazine well of a firearm;   a power assembly affixed to the end plate, the power assembly comprising:
 a power storage device; and 
 a second electrical bus coupled between the power storage device, the first electrical bus, and the plurality of magnetic sensors. 
   
     
     
         18 . The round-counting magazine of  claim 17 , further comprising a side cover arranged over the channel and the recess. 
     
     
         19 . The round-counting magazine of  claim 18 , further comprising a side cover arranged over and partially within at least one of the channel and the recess. 
     
     
         20 . The round-counting magazine of  claim 17 , further comprising a side cover overmolded onto the plurality of magnetic sensors and the first electrical bus. 
     
     
         21 . The round-counting magazine of  claim 17 , wherein the channel and the recess are on an outside of the housing. 
     
     
         22 . The round-counting magazine of  claim 17 , wherein the channel and the recess are on an inside of the housing. 
     
     
         23 . The round-counting magazine of  claim 17 , wherein the plurality of magnetic sensors are arranged on a circuit board within the channel. 
     
     
         24 . The round-counting magazine of  claim 17 , wherein the plurality of magnetic sensors are fabricated directly to a material forming the channel.