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A drum magazine for a gun has a housing with a feed throat extending from the housing and within the housing are mounted concentric sprockets. The sprockets have serrations for nesting cartridges and each sprocket is independently rotatable with stops for limiting the rotation of the outer sprocket

A drum magazine for a gun has a housing with a feed throat extending from the housing and within the housing are mounted concentric sprockets. The sprockets have serrations for nesting cartridges and each sprocket is independently rotatable with stops for limiting the rotation of the outer sprocket and stops limiting rotation of the intermediate sprocket. A latch is arranged to prevent rotation of the outer sprocket in a counter direction to the direction of feeding cartridges out of the magazine until the intermediate sprocket is rotated in the counter direction a predetermined amount. A connector is connected to the outer sprocket and passes through the outer sprocket to engage with the cartridges nested in the intermediate sprocket so that by virtue of the connector, the sprockets rotate together. A similar connector is provided between the intermediate sprocket and the inner sprocket. A U-shaped pusher is provided to push the last few remaining cartridges in the magazine out of the feed throat.

대표청구항 ▼

1. A drum magazine for a gun including a stationary housing, an inner rotatably mounted member and an outer rotatably mounted member substantially concentric therewith, drive means for rotating the members in a first direction, stop means for limiting rotation of the outer member with respect to the

1. A drum magazine for a gun including a stationary housing, an inner rotatably mounted member and an outer rotatably mounted member substantially concentric therewith, drive means for rotating the members in a first direction, stop means for limiting rotation of the outer member with respect to the housing, and latch means between the outer member and the housing arranged to lock when the stop means limit the rotation of the outer member to thereby prevent rotation of the outer member in a counter direction to the first direction until the inner member is rotated in said counter direction a predetermined amount. 2. A drum magazine as claimed in claim 1, wherein said members each comprise a substantially concentric sprocket means, each said sprocket means including a tubular member and having an outer periphery provided with a plurality of serrations arranged to nest a plurality of cartridges. 3. A drum magazine as claimed in claim 2, wherein more than two sprocket means are provided, and the stop means comprise abuttable stop members provided between the housing and the outermost sprocket means and between adjacent sprocket means except between the innermost sprocket means and the sprocket means adjacent thereto. 4. A drum magazine as claimed in claim 3, wherein further latch means are provided between adjacent sprocket means except between the innermost sprocket means and the sprocket means adjacent thereto, each said latch means being engageable when the cooperating stop members abut each other such that each said latch means prevent rotation of an associated latched sprocket means until the serrations thereof are required to be filled with cartridges. 5. A drum magazine as claimed in claim 4, wherein the latch means between the housing and the outermost sprocket means comprise a strip member pivotally connected to the outermost sprocket means and spring biassed toward the inner peripheral wall of the housing, and a recess in said peripheral wall, the strip member having an ear for engaging with the lip of the recess when the stop members associated with the housing and the outermost sprocket means abut. 6. A drum magazine as claimed in claim 5, wherein the further latch means between adjacent sprocket means comprise a strip member pivotally connected to the inner of the two adjacent sprocket means which is spring biassed toward the inner wall of the tubular member of the adjacent outer sprocket means, and a recess in said inner wall, the strip member of the further latch means having an ear for engaging with a lip of the recess in said inner wall when the stop members associated with the adjacent sprocket means abut. 7. A drum magazine as claimed in claim 5, wherein said strip member has a tang on the opposite side of the associated pivot from the ear which tang passes through the tubular member of the sprocket means to which it is attached and toward the adjacent inner sprockey means, whereby the tang is arranged to have a length sufficient to be contacted by a cartridge on said adjacent inner sprocket means for the strip member to be rotated thereby such that the ear of the strip member disengages its associated lip and permits the sprocket means to which the strip member is attached to rotate. 8. A drum magazine as claimed in claim 7, wherein the strip member is located in the wall of the tubular member of the sprocket means to which the strip member is attached and arranged to be depressed therein by cartridges on said sprocket means. 9. A drum magazine as claimed in claim 2, wherein the sprocket means each comprise the tubular member with at least two circular, radially extending flanges spaced therealong, each flange having serrations arranged to nest a plurality of cartridges therebetween, the serrations of the innermost sprocket means being spaced from the inner surface of the next adjacent outer sprocket means by substantially the same distance as the serrations of the outermost sprocket means are from the housing interior peripheral wall, a cartridge feed aperture in each tubular member except the innermost for permitting cartridges to pass through the apertured tubular members and feed ramps arranged to guide cartridges from each of the sprocket means to a feed throat of the housing. 10. A drum magazine as claimed in claim 9, wherein the strip member has a finger adjacent said ear but directed inwardly to pass through an aperture in the tubular member of the sprocket means to which said strip member is attached, said finger having a length and position such that when the strip member is depressed by cartridges it is displaced between cartridges on the inner adjacent sprocket means to rotate said adjacent sprocket means in a direction against the force of the drive means to thereby free the pressure on the cartridges in the feed ramps. 11. A drum magazine as claimed in claim 2, wherein each sprocket means is provided with the serrations directly in the outer periphery of the tubular member. 12. A drum magazine as claimed in claim 1, wherein the rotatably mounted members are concentrically arranged within the housing and the outermost member comprises a base plate and cartridge guide rails extending from said base plate which define substantially concentric cartridge paths and a bridge linking said paths. 13. A drum magazine as claimed in claim 12, wherein the inner member is a driving means which comprises a spring driven rotor, and a pivotal pusher connected to said rotor for applying force to push the cartridges around said paths. 14. A drum magazine for a gun as claimed in claim 1, wherein there is provided a connector having a part thereof attached to one of said members through which drive is capable of predeterminedly passing from one of said members to the other said member such that the members rotate together and wherein disconnection of said connector enables one member to rotate with respect to the other member. 15. A drum magazine as claimed in claim 14, wherein both members are capable of carrying cartridges. 16. A drum magazine as claimed in claim 15, wherein the members are sprocket means each having an outer periphery having a plurality of serrations arranged to nest a plurality of cartridges. 17. A drum magazine as claimed in claim 16, wherein the sprocket means comprise at least two circular, radially extending flanges axially spaced along a tubular member, each flange having serrations to nest a plurality of cartridges between said flanges. 18. A drum magazine as claimed in claim 2, wherein the housing is a plastic moulding which is pan-shaped and has a cover also formed by moulding plastics. 19. A drum magazine as claimed in claim 18, wherein a recessed track is formed in the housing and cover for locating and guiding the sprocket means. 20. A drum magazine as claimed in claim 2, wherein the sprocket means are made from a plastic material. 21. A drum magazine for a gun as claimed in claim 2, wherein said housing has a peripheral wall defining a circularly cross-sectioned interior, a cover for the housing, a feed throat extending through said wall for releasing cartridges from said housing, and at least two rotatable concentric sprocket means, the sprocket means each comprising a concentric tubular member, at least two circular, radially extending flanges spaced therealong, each flange having serrations to nest a plurality of cartridges therebetween, a cartridge feed aperture in each tubular member except the innermost for permitting cartridges to pass from the inner sprocket means to the other sprocket means, feed ramp means arranged to guide cartridges from each of the sprocket means to the feed throat, and a pusher mounted on the inner most sprocket means which is arranged to push those remaining cartridges not pushed by nested cartridges along the feed ramp means to the feed throat, wherein the pusher comprises a U-shaped member with the free ends thereof mounted on a pivot extending between the flanges of the innermost sprocket means, each limb of the U-shape being adjacent an associated flange and a rod located along the base of the U-shaped member which is nested in similar fashion to the cartridges on the flanges, whereby the length of the limbs of the U-shaped member is sufficient to enable the last cartridge in the magazine to be pushingly fed by the rod to the outer extremity of the feed throat. 22. A drum magazine as claimed in claim 21, wherein a last round stop actuator comprise a spring biassed member located adjacent to a limb of the pusher for travelling with said limb, whereby the spring biassed member is extended outside the housing when said pusher rod is extended toward the outer extremity of the feed throat. 23. A drum magazine as claimed in claim 22, wherein the last round stop actrator is a leaf spring having one end connected to the pivot of the pusher and the other end thereof connected to a button, whereby the button is adjacent and biassed toward the cover and protrudes therefrom when the rod is extended in the feed throat. 24. A drum magazine as claimed in claim 22, wherein the last round stop actuator is a plunger and spring assembly located in the rod of the pusher arranged so that the plunger is adjacent and biassed toward the cover and protrudes therefrom when the rod is extended in the feed throat. 25. A drum magazine as claimed in claim 2, wherein the sprocket means are driven by a torsion spring, there being a central axle and a slot in the tubular member of the innermost sprocket means with said torsion spring tensioned therebetween. 26. A drum magazine as claimed in claim 21, wherein stop means are provided for sequentially limiting the relative rotation between each of the sprocket means and the housing, which stop means serve to sequentially align the feed ramp means of the sprocket means in turn, starting with the outer sprocket means. 27. A drum magazine for a gun including a stationary housing, an inner rotatably mounted member and an outer rotatably mounted member substantially concentric therewith, drive means for rotating the members in a first direction, stop means for limiting rotation of the outer member with respect to the housing, latch means between the outer member and the housing arranged to lock when the stop means limit the rotation of the outer member to thereby prevent rotation of the outer member in a counter direction to the first direction until the inner member is rotated in said counter direction a predetermined amount, said latch means including a connector having a part thereof attached to one of said members through which drive is capable of predeterminedly passing from one of said members to the other said member such that the members rotate together and wherein disconnection of said connector enables one member to rotate with respect to the other member.