1. Field of the Invention
The subject invention relates to ammunition feed systems and, more particularly, to a feed system and associated magazine providing continuous positive round control at firing rates of on the order of 6,000 rounds per minute, wherein the effective feed rate is doubled over the transfer rate of the magazine and wherein the packaging density is maximized. Hereinafter, rounds of ammunition may be referred to interchangeably as rounds, cartridges, bullets, or ammunition.
2. Description of Related Art
The existing armament system of a typical fighter aircraft feeds a gun operating at 6,000 rounds per minute, which translates to 100 rounds per second. The arrangement uses a drum-like feed unit disposed under the gun, which employs a helical feed and pickoff of rounds to achieve the required high feed rate. The ammunition is radially disposed about a helical member within the drum container, and when the unit is operated, the helix acts as a jackscrew, forcing ammunition from the drum at the desired rate. The drum-like unit takes up an exact cylindrical space, affording no flexibility of the installation envelope. In many cases a cylinder does not offer optimum packaging density, and it has appeared that additional space for avionics could be gained by employing a linear linkless ammunition feed system.
Linear linkless systems offer a very high packaging density which results from transporting rounds in a flexible ladder-type conveyor routed in serpentine fashion through adjacent linear paths in the magazine structure. While linear linkless systems are very space efficient, the operational rate of a conventional system matches the 100-round-per-second feed rate, resulting in tremendous wear and tear on the system and a large horsepower drive requirement.
Prior art is known which offers a partial solution to the high operating rate of a linear linkless system by placing rounds in two joined rows, nose to base, and moving transversely to the round axis. This double row conveyor arrangement is commonly referred to as a two-bay linear linkless magazine, and it operates at one-half of the gun rate. The drawback to this arrangement is that the two-bay width must be some percentage longer than two cartridge lengths and therefore is not applicable to installations requiring a narrow profile.