A machine gun top cover assembly includes a top cover door attached to a main housing. The top cover assembly defines a rear transverse track section and a front transverse track section for guiding bolt assemblies of the gun. As the machine gun rotor assembly rotates, the rear track section prevents the bolt assemblies from moving into position for firing, and the front track section guides the bolt assemblies into position for firing. A selector switch on the top cover door selects between: (i) a safe position wherein, each of the bolt assemblies are sequentially directed into the rear track section; and (ii) a fire position wherein the bolt assemblies are directed into the front track section. The top cover assembly can include a solenoid for moving the selector switch between the safe position and the fire position in response to an electrical control signal.

BACKGROUND

The present invention relates generally to automatic weapons of the Gatling machine gun type. More specifically, it relates to a top cover assembly for such a machine gun that includes a safing selector that makes the machine gun easier to use.

The Gatling-type machine gun is a multi-barreled machine gun with a high rate of fire. It features Gatling-style rotating barrels with an external power source, such as an electric motor. Long existing motivations in the design of Gatling-type miniguns have been to minimize jams, extend the operational life and improve ease of use of such guns.

One Gatling-type machine gun is the M134 minigun, which is a six-barreled, electrically-driven machine gun originally designed and built by General Electric Company in the mid 1960's for the United States military. The M134 minigun (hereinafter referred to as either a minigun or machine gun) utilizes a main housing, which encloses and supports a main rotary body known as a rotor assembly. Cartridges, each of which represents a single round of ammunition, are handled within the main housing by bolt assemblies. The minigun has six bolt assemblies, one associated with each of the six barrels. The six bolt assemblies are slidably attached to and surround the rotor assembly. The rotor assembly comprises the core axis of the minigun. The six barrels are attached to the forward portion of the rotor assembly and are arranged for rotation as a cluster around the core axis of the minigun. As the rotor rotates, the bolt assemblies are driven forward and rearward by a helical track incorporated within the main housing which, in turn, causes cartridges to be delivered to the bolt assemblies, chambered, and fired. The empty cartridges are extracted from the chambers and ejected. The rotor is rotated by a series of gears driven by an electric motor.

FIGS. 1-4illustrate an assembly of the M134 minigun known in the prior art as the top cover and safing sector assembly. The top cover and safing sector assembly is externally attached to the main housing of the minigun. The safing sector forms a portion of the helical track used to drive the minigun bolt assemblies forward and rearward. The top cover is attached to the safing sector by a hinge pin that allows the top cover to pivot independently of the safing sector. The pivot feature between the top cover and the safing sector allows the top cover to be opened and closed independently of the safing sector. The top cover opens like a hatch to allow the operator access to the inner workings of the minigun. After the top cover has been opened, the safing sector can be either partially or completely removed from the minigun. The purpose of removing the safing sector is to dislocate the critical section of the helical track that causes the bolt assemblies to fire the cartridges. After the safing sector has been partially or completely removed, the minigun cannot be fired, hence the term “safing sector.”

Disabling the minigun so that it cannot fire is referred to as “safing” the gun. There are essentially two situations in which it is desirable to safe the gun. The most common is when the minigun is loaded with live cartridges and is not in use. The second situation is when a jam occurs during use of the minigun, causing it to stop firing. In order to safe the gun in either of these situations, a the top cover and safing sector system ofFIGS. 1-4requires the operator to first open the top cover to facilitate removal of the safing sector from its firing position. In a combat or training environment, safing the gun by removing both the top cover and safing sector is time consuming and inconvenient.

Furthermore, when a jam occurs, the operator may be required to remove live cartridges from the rotor assembly without firing them. Doing so requires rotation of the barrels of the minigun. In order to cycle live cartridges through the minigun without firing them, the top cover and safing sector must be removed before rotating the barrels. Following removal of the top cover and safing sector ofFIGS. 1-4, the barrels can be rotated manually, but not electrically. If the barrels are inadvertently rotated electrically with the safing sector in its partially or completely open position, the bolt assemblies will be damaged and the minigun will become inoperable. The barrels can only be rotated electrically when the safing sector is in its closed and firing position.

The prior art top cover and safing sector assembly described above and illustrated inFIGS. 1-4is disadvantageous in that safing the gun requires opening of the top cover and removing the safing sector. Simply opening the top cover does not provide improved safety or functionality. In addition, manual rotation of the hot barrels following recent use of the gun is difficult. Thus, safing a minigun that utilizes the top cover and safing sector ofFIGS. 1-4is at the very least inconvenient when attempting to do so in combat or training environments.

It would therefore be advantageous to provide a replacement for prior art top covers and safing sectors that will enable an operator to safe a minigun without opening the top cover and to rotate the barrels electrically after the minigun has been safed. It is an object of the present invention to provide such a replacement.

It is another object of the present invention to provide a top cover assembly for a Gatling-type multi-barrel machine gun that includes an improved mechanism for safing the weapon, which allows the user to easily switch between “Fire” and “Safe” settings.

It is still another object of the invention to provide a top cover assembly with such a mechanism that can be controlled both manually and remotely.

SUMMARY

To achieve the foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described in this document, there is provided a top cover assembly for a Gatling-type machine gun, which gun has a main housing, a rotor assembly supported by the main housing and adapted for being rotated, a plurality of bolt assemblies attached to the rotor assembly, and a helical track extending longitudinally within the main housing for driving the bolt assemblies in forward and rearward directions in response to rotation of the rotor assembly. The top cover assembly includes a top cover door coupled to a portion of the main housing and defining a transverse front track section and a transverse rear track section. In a presently preferred embodiment, the top cover door is hingedly coupled to a portion of the main housing, and each of the front track section and the rear track section is disposed on the inside of the top cover door. A selector switch is positioned on the outside of the top cover door for selecting between: (i) a safe position wherein each of the plurality of bolt assemblies is sequentially directed into the rear track section when the rotor assembly rotates; and (ii) a fire position wherein each of the plurality of bolt assemblies is directed into the front track section when the rotor assembly rotates. The rear track section is configured so that, as the rotor assembly rotates, the rear track section will prevent a bolt assembly from moving into position for firing. The front track section is configured so that, as the rotor assembly rotates, the front track section will guide a bolt assembly to move into position for firing.

In certain advantageous embodiments, the selector switch is coupled to a guide arm disposed on the inside of the top cover door such that: (i) when the selector switch is in the safe position, the guide arm is positioned in a first position to sequentially direct each of the plurality of bolt assemblies into the rear track section as the rotor assembly rotates; (ii) when the selector switch is in the fire position, the guide arm is positioned in a second position to direct a bolt assembly into the front track section as the rotor assembly rotates; and (iii) when the safe selector is moved between the safe position and the fire position, the guide arm is moved between the first position and the second position.

In some embodiments, the top cover assembly includes a selector lock disposed on the top cover door and configured to restrict the selector switch from being rotated between the safe and fire positions unless the selector lock is released.

In some advantageous embodiments, the top cover assembly can be configured for remote operation. For example, in one such embodiment the top cover assembly includes a solenoid configured to actuate movement of the selector switch between the safe position and the fire position in response to an electrical control signal. To provide a fail-safe in the event of a loss of power, the solenoid can be configured to hold the selector switch in the safe position when electric power to the solenoid is removed.

DESCRIPTION

Referring generally toFIGS. 1-4, there is shown a prior art top cover30and safing sector31and the way in which they are hingedly connected adjacent each other and to a main housing8of a conventional minigun. A helical track extends longitudinally within the main housing8and forms a continuous track with a track section20that is formed in the underside of the safing sector31, as illustrated inFIGS. 3 and 4. Conventional bolt assemblies each include a roller bearing that rides in the helical track through the safing sector track section20. As the barrels of the minigun rotate, the roller bearing enters the track section20at location23ofFIG. 4and exits the track section20at location24. The safing sector track section20includes forward and aft camming portions21,22, respectively. The camming portions21,22of the safing sector track section20are both bearing surfaces that force the bolt assemblies in forward and aft directions, respectively. A straight portion of the track section20, illustrated by sidewalls25ofFIG. 4, serves as a guide between forward and aft camming portions21,22and does not produce a camming action.

Still referring toFIG. 4, as each of the bolt assemblies enters the safing sector track section20at location23and is forced forward by the forward camming portion21, the firing pin of each bolt assembly is placed under heavy spring pressure in preparation for firing a respective cartridge. Just before the bolt assembly crests forward of the camming portion21of the track section20and enters the straight portion thereof defined by the sidewalls25, the cartridge is fired and the spring pressure is released. The bolt assembly continues through the straight portion of track section20until reaching the aft camming portion22of the track section20, at which point the bolt assembly is forced in the aft direction, guiding the bolt assembly back into the portion of the helical track within main housing8. It is the forward camming portion21of the safing sector track section20that causes the cartridge to be fired and the aft camming portion22of track section20that redirects the bolt assembly and guides it back into the helical track within main housing8. When safing the gun by removing the safing sector31, it is the removal of forward camming portion21of track section20that inhibits the minigun from firing. When the safing sector31is removed, the aft camming portion22of the track section20is also removed and the bolt assembly will not be properly guided back into the portion of helical track within main housing8by aft camming portion22. Consequently, inadvertently rotating the barrels electrically with the safing sector open can damage the bolt assemblies.

FIG. 5illustrates a Gatling-type machine gun10suitable for use with the present invention. The Gatling-type machine gun10includes a barrel assembly12, an electric drive motor14to rotate the barrel assembly12, a delinking feeder16, a clutch assembly (not shown), a gun main housing8, a gun control unit13, and a spade grip15. The barrel assembly12includes a barrel clamp assembly17to which a plurality of barrels18are circumferentially mounted. In the context of the specification, the terms “rear” or “rearward” mean in the direction towards the chamber end of the barrels18, while the terms “front” or “forward” mean in the direction towards the muzzle end of the barrels18.

Still referring toFIG. 5, ammunition is fired sequentially through the barrels18in a known fashion, i.e., first one barrel is used, then the next, then the next, etc. An electric cable (not shown) supplies power from the gun control unit13to the drive motor14. The delinking feeder16, which is an ammunition feed device, is engaged and disengaged via the electric cable. To provide access to the interior of the delinking feeder16, an access door assembly19is mounted on the delinking feeder16. The access door assembly19includes an access door that is movable between a first closed operative position and a second open position to facilitate the loading of an ammunition belt of linked cartridges (not shown).

As is well known to those of skill in the art, in the operation of the minigun10, the drive motor14causes the barrel assembly12to rotate, and each barrel18fires sequentially in rapid succession. During such operation, the delinking feeder16receives the ammunition belt of linked cartridges, sequentially separates or “delinks” the cartridges from the ammunition belt and feeds the cartridges to a receiver in the main housing8for firing. A helical cam track11extends longitudinally within the main housing8and guides each bolt assembly from a rear position where the cartridge is fed into the receiver to a forward position where the bolt compresses, causing the head to rotate, lock and fire the cartridge. Each bolt assembly includes a roller bearing that rides in the helical track11and forces the bolt assembly into the required positions.

Still referring toFIG. 5, when an arming switch on the gun control unit13is activated, and one or both firing buttons are then depressed, the gun will fire. When the firing buttons are released, the delinking feeder16is disengaged so the ammunition supply is discontinued. The electric drive motor14continues to rotate for a short period of time so that the weapon is cleared of remaining ammunition before stopping. A booster motor override control button on the gun control unit13, when depressed, activates an ammunition booster motor on the ammunition magazine (not shown) to facilitate the loading of the weapon. The booster motor pushes the ammunition belt from the ammunition magazine, through the feed chute, and to the weapon where it is inserted in the delinking feeder16, readying the weapon for firing.

In accordance with the present invention, the machine gun10includes a novel top cover assembly, generally designated by the reference numeral100. Referring toFIGS. 6-12, on one embodiment, the top cover assembly100includes a top cover door101having a rearward end120and a forward end122. The top cover door rearward end120is hingedly connected to the main housing8of the machine gun. On the underside of the top cover door forward end122are two transverse track sections, i.e., a front track section124and a rear track section126. A selector switch102is positioned on the outside of the top cover door101and is mounted to a track selector103(seeFIG. 6) so that the selector switch102and track selector103can be rotated together between a safe position (as shown inFIG. 9A) and a fire position (as shown inFIG. 9B). The track selector103is generally L-shaped (seeFIG. 6) and includes a shaft128that extends through a hole108(seeFIG. 12) in the top cover door101and a guide arm130that is disposed on the inside (i.e., the underside) of the top cover door101. The selector switch102is mounted on the track selector shaft128with a slotted pin106and is disposed on the outside of the top cover door101. A selector lock104is mounted to the top cover door101on another pin106that fits within another hole109in the top cover door101. The selector lock104floats within a slot110in the top cover door101. A compression spring105fits over the slotted pin106and forces the selector lock104outward into engagement with the selector switch102such that it restricts the selector switch102from being rotated between the safe and fire positions unless the selector lock104is first depressed. In this configuration, the selector lock104cannot be removed unless the selector switch102is first removed.

Referring toFIGS. 9-11, when the track selector switch102is in the safe position as shown inFIGS. 9A and 10A, the track selector guide arm130is disposed as shown inFIG. 11A. In this position, as the barrel assembly12rotates, each of the bolt assembly roller bearings is directed into the rear track section126, which prevents the bolt assemblies from fully compressing and thereby prevents the minigun from firing. As the barrel assembly12continues to rotate, the rear track section126guides the bolt assembly back into the helical track11within main housing8.

When the track selector switch102is rotated to the fire position as shown inFIGS. 9B and 10B, the track selector103and guide arm130rotate to the position shown inFIG. 11B. In this position, as the barrel assembly12rotates, each of the bolt assembly roller bearings is directed into the front track section124, which forces the bolt assembly to move in a forward direction and thereby compresses the bolt, causing the head to rotate, lock and fire the cartridge, as described above. As the barrel assembly12continues to rotate, the front track section124guides the bolt assembly back into the helical track11within the main housing8. When the selector switch102is in either of the safe or firing positions, the selector lock104will prevent the selector switch102from disengaging and moving between positions without operator input. To move the selector switch102between positions, the operator must first depress the spring-loaded selector lock104.

According to one advantageous aspect of the present invention, the top cover assembly100can be configured for remote operation. In one such configuration, shown in the embodiment ofFIGS. 10A and 10B, remote operation of the selector switch102is actuated by a solenoid108, which is managed from the gun control unit13. The top cover assembly100does not include a selector lock104. The solenoid108is configured to actuate movement of the selector switch102between the safe position and the fire position in response to an electrical control signal, which is received from the gun control unit13. The selector switch102is in the safe mode when the plunger of the solenoid108is extended (seeFIG. 10A) and is in fire mode when the plunger of the solenoid108is retracted (seeFIG. 10B). When the solenoid108is not receiving power from the gun control unit13, an internal return spring will extend the solenoid plunger in order to default the system to its safe mode. As the gun control unit13runs through its process, when it cuts power to the solenoid108an internal solenoid spring will force the assembly into the safe position. This also provides a fail-safe in the event of a loss of power.

Upon reading this disclosure, those skilled in the art will appreciate that various changes and modifications may be made to the preferred embodiments of the invention and that such changes and modifications may be made without departing from the spirit of the invention. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.