US 4,658,700 A · Drum magazine

Abstract

This invention relates to magazines for guns. The drum magazine of the present invention comprises one or two generally cylindrical drums with openings for the exit of cartridges from within the drum. A spring driven rotor within the drum carries two concentric rings of cartridges in a channel defined by the outer circumference of the rotor and the interior of the cylindrical drum wall. The rotor engages the inner concentric ring of cartridges and each cartridge in the outer ring of cartridges is forced to move by contact with a cartridge of the inner ring. During feeding, the cartridges are advanced as two rings until they meet the cam blade, which gradually forces the cartridges into a single column which moves approximately twice as fast as the velocity of the cartridges in the rotor. When the last cartridge leaves the rotor during feeding and enters the exit passage, a follower arm is provided to continue to push the last cartridge out of the magazine.

Claims41

Dependent claims

A drum magazine for successively feeding a plurality of cartridges to a firearm, comprising:

(a) a drum shaped housing means having a cartridge exit opening extending from the side of said housing means;
(b) rotational cartridge carrying means within said housing means which defines a cartridge space, between said cartridge carrying means and the inner wall of said housing means, for two offset concentric rings of cartridges, wherein each of the cartridges of the outer concentric ring are nested in the recess formed by two adjacent cartridges in the inner concentric ring of cartridges and are urged to revolve around said drum by the rearward of said adjacent cartridges in the inner ring of cartridges, said rotational cartridge carrying means comprising means for individually defining the positions of each cartridge of the inner ring of cartridges and for individually urging each of said cartridges of the inner ring of cartridges to revolve around said drum as said cartridge carrying means rotates;
and
(c) cam means within said housing means defining, with said housing means, a passage from the cartridge space to the exit opening of said housing means, for urging two offset concentric rings of cartridges alternately together into a single row as said cartridges are moved out of said magazine.

1 more element

A magazine for successively feeding a plurality of cartridges to a firearm, comprising:

(a) two drum shaped housing means, each having a cartridge exit opening extending from the side of said housing means;
(b) connecting means for joining each of said housing means at the exit openings of each of said housing means, said connecting means having passages within for receiving single rows of cartridges exiting from the exit openings of each of said housing means and merging the two rows of cartridges into a staggered double row of cartridges as they exit said connecting means;
(c) extension means extending from said connecting means for placement in round-feeding relation with a firearm, said extension having a round-feeding opening and having a passage from said connecting means to the round-feeding opening approximately the width of a staggered double row of cartridges;
(d) rotational cartridge carrying means within said housing means which defines a cartridge space, between said cartridge carrying means and the inner wall of said housing means, for two offset concentric rings of cartridges, wherein each of the cartridges of the outer concentric ring are nested in the recess formed by two adjacent cartridges in the inner concentric ring of cartridges and are urged to revolve around said drum by the rearward of said adjacent cartridges in the inner ring of cartridges, said rotational cartridge carrying means comprising means for individually defining the positions of each cartridge of the inner ring of cartridges and for individually urging each of said cartridges of the inner ring of cartridges to revolve around said drum as said cartridge carrying means rotates;
and
(e) cam means within said housing means defining, with said housing means, a passage from the cartridge space to the exit opening of said housing means for urging two offset concentric rings of cartridges alternately together into a single row as said cartridges are moved out of said magazine.

3 more elements

Dependencies are inferred from the claim text.

Drum magazine

Life of this patent

Drum magazine

Life of this patent

Abstract

Claims41