Four-stack cartridge magazine

Claim 2

A cartridge magazine for a firearm having a reciprocal bolt comprising, a case divided into a primary chamber and a secondary chamber, each of said chambers being adapted to hold a double stack of cartridges in staggered arrangement, self-contained means for successively positioning the cartridges for pickup by the bolt, and a partition for separating said primary and secondary chambers, said partition including a divider section mounted to said case for pivotal displacement about one axis to a position opening said chamber simultaneously for loading the cartridges thereinto and for rotational displacement about another axis normal to said one axis to releasably retain the cartridges in said secondary chamber until those in said primary chamber are entirely removed therefrom.

Claim 3

The magazine as defined in claim 1 wherein said case comprises a first side related to said primary chamber and a second side related to said secondary chamber, said sides each including an upper portion curving upwardly and inwardly to form therebetween a mouth arranged to successively receive the cartridges from said chambers for pickup by the bolt, and including a spring-pressed follower disposed in each of said chambers for biasing the cartridges therein towards said mouth, a partition separating said primary and secondary chambers, a divider section of said partition displaceably mounted in said case for cooperation with said upper portions to successively position the cartridges in said primary chamber at said mouth for pickup by the bolt and simultaneously hold the cartridges in said secondary chamber away from contact by the bolt until those in said primary chamber are entirely removed therefrom and to open the adjacent ends of said compartments for loading the cartridge into, and means cooperating with said divider to release the cartridges from said secondary chamber for successive pickup by the bolt when those in said primary chamber are entirely removed therefrom.

Claim 4

The magazine as defined in claim 3 wherein said last means cooperating with said divider comprise a slide displaceably mounted on said case so as to releasably hold said divider in an operative position relative to said upper portions for retaining the cartridges in said secondary chamber until those in said primary chamber are entirely removed therefrom, and a lug on said follower in said primary chamber arranged to displace said slide for release of said divider when the last cartridge in said secondary chamber is picked up by the bolt to permit rotational displacement of said divider by the bias of the cartridges in said secondary chamber thereagainst to release the cartridges therein for successive pickup by the bolt at said mouth.

Claim 5

The magazine as defined in claim 3 and including means for mounting said divider for pivotal displacement about one axis between the operative position and a lower depressed position and for rotational displacement about another axis normal to said one axis between a blocking position wherein the cartridges in said secondary chamber are blocked by said divider from displacement to said mouth for pickup by the bolt when said divider is also in the operative position and a release position wherein the cartridges in said secondary chamber are released by said divider for displacement to said mouth, spring means cooperating with said divider for biasing said divider to the operative position, a finger extending from said divider for reception by an opening in said case, an upper portion of said opening cooperating with said finger for limiting rotational displacement of said divider between the blocking and release positions when in the operative position, and a pocket portion of said opening disposed for receiving said finger when said divider is actuated to the depressed position by downward pressure of the cartridges thereagainst for centering said divider between the blocking and release positions to open said chambers for loading the cartridges thereinto.

Claim 6

The magazine as defined in claim 4 wherein said slide includes a tang arranged for contact with said finger when said divider is in the operative position to releasably block said divider in the blocking position, and arranged to be free of said finger through displacement of said slide by said follower in said primary chamber when the last one of the cartridges in said primary chamber is picked up by the bolt.

Claim 7

The magazine as defined in claim 5 wherein said follower in said primary chamber is contoured commensurate with said first side upper curved portion and said divider to permit overtravel of said follower towards said mouth after the last one of the cartridges in said primary chamber is picked up by the bolt, and said lug on said follower in said primary chamber is located thereon to actuate said slide for sufficient displacement during the overtravel to displace said tang of said finger for release of said divider.

Claim 8

The magazine as defined in claim 5 wherein said divider is provided along the top thereof with a first edge arranged for cooperation with said upper curved portion of said first side to successively retain the cartridges in said primary chamber at said mouth for pickup by the bolt when said divider is in the blocking position, and with a second edge arranged for cooperation with said upper curved portion of said second side to block upward displacement of the cartridges in said secondary chamber to a position in said mouth for successive pickup by the bolt when said divider is in the blocking position, and said first edge and said second edge being related to said upper curved portions so as to release the cartridges in said secondary chamber and successively retain the cartridges therein in position for pickup by the bolt when said divider is in the release position.