Machine gun top cover and safing blade assembly

A top cover and safing blade assembly replaces the prior art top cover and safing sector in 7.62 miniguns. The top cover and aft camming portion of a longitudinal helical track are combined in a single unit, thus permitting the forward camming portion of the helical track, incorporated in the safing blade, to be removed separately. Safing the gun by opening the safing blade and rearming it by closing the safing blade can be accomplished in far less time than is required in prior art safing systems. Live cartridges can be quickly cleared from the minigun by electrically rotating the barrels after the safing blade has been locked in its open position.

REFERENCE TO RELATED APPLICATION

This application is related to the subject matter of U.S. patent application Ser. No. 11/585,529 entitled MACHINE GUN filed on Oct. 24, 2006, by the same inventor.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates generally to automatic weapons of the Gatling machine gun type and, more specifically, to the class of such guns known as 7.62 miniguns and improvements therein that serve to make them easier to use by incorporating a safing blade mechanism in the top cover of such guns.

The 7.62 minigun is a six-barreled, electrically-driven machine gun originally designed and built by General Electric Company in the mid 1960's for the U.S. military. This gun has been in use since its inception by both U.S. and foreign military forces.

The 7.62 minigun, hereinafter referred to as either a minigun or machine gun, utilizes a main housing enclosing and supporting 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 includes six bolt assemblies, one associated with each of the six barrels. The six bolt assemblies are 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 means of a series of gears driven by an electric motor.

FIGS. 1-4depict a basic prior art top cover and safing sector assembly. The top cover and safing sector assembly is externally attached to the main housing of a 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 means of a semi-permanent retaining 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 of the minigun quick access to the inner workings thereof. After the top cover has been opened, the safing sector can be either partially or completely removed from the minigun. The purpose of partially 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 hereinafter referred to as safing the gun. Since their inception, all 7.62 miniguns have employed top covers and safing sectors of the same basic design.

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 conventional top cover and safing sector system requires 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 a time consuming and physical inconvenience.

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 prior to rotating the barrels. Following removal of the top cover and safing sector, 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 removal of 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 prior art minigun is 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 top cover and safing sectors of the prior art 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.

In accordance with the illustrated preferred embodiment of the present invention, a one-piece top cover and safing blade assembly replaces the prior art two-piece top cover and safing sector. The top cover and safing blade assembly is arranged to be mounted using existing locating features within the main housing of the minigun, thereby facilitating its ready adaptation to existing miniguns.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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. As illustrated inFIGS. 3 and 4, a helical track20is provided in sating sector31. Helical track20extends longitudinally within main housing8. Conventional bolt assemblies include a roller bearing that rides in helical track20. As the barrels of the minigun rotate, the bolt assemblies enter helical track20at location23ofFIG. 4and exit helical track20at location24. Helical track20includes forward and aft camming portions21,22, respectively. Camming portions21,22of helical track20are both bearing surfaces that force the bolt assemblies in forward and aft directions, respectively. A straight section of helical track20, illustrated by sidewalls25ofFIG. 4, serves as a guide between forward and aft camming portions21,22and does not produce a camming action. As the bolt assemblies enter helical track20at location23and are forced forward by forward camming portion21thereof, the firing pin of each bolt assembly is placed under heavy spring pressure in preparation for firing a respective cartridge. Just prior to a given bolt assembly cresting forward camming portion21of helical track20and entering the straight section thereof defined by sidewalls25, the cartridge is fired and the spring pressure is released. The bolt assembly continues through the straight section of helical track20defined by sidewalls25until reaching aft camming portion22of helical track20, at which point the bolt assembly is forced in the aft direction, guiding the bolt assembly back into the portion of helical track20within main housing8. It is forward camming portion21of helical track20that causes the cartridge to be fired and aft camming portion22of helical track20that redirects the bolt assembly and guides it back into the helical track20within main housing8. When safing the gun by partially or completely removing the prior art safing sector31, it is the removal of forward camming portion21of helical track20that inhibits the minigun from firing. In addition, when safing the gun, aft camming portion22of helical track20is also removed, further inhibiting the barrels from being rotated electrically. If the safing sector31is removed and the barrels are rotated electrically, the bolt assemblies will be damaged as the result of not being properly guided back into the portion of helical track20within main housing8by aft camming portion22of helical track20.

Referring now generally toFIGS. 5-10, there is shown a top cover and safing blade assembly1in accordance with the present invention. Top cover and safing blade assembly1is adapted for attachment to main housing8of a conventional minigun and includes a top cover2and a safing blade3. Top cover2includes a pair of side retainer pin housings13,14, a pair of spring-loaded retainer pins4,9, a pair of retainer pin springs32, a bearing bushing10, a latching mechanism retainer18, and a plunger keeper16. Spring-loaded retainer pins4,9serve to attach top cover and safing blade assembly1to main housing8. Retainer pins4,9are spring loaded in their open or retracted position and extend through forward holes6of top cover2into locater holes in main housing8. Top cover and safing blade assembly1is attached to main housing8by pushing the retainer pins4,9forward, against the pressure applied by retainer pin springs32, into the locator holes within main housing8and then locking them into the forward position by rotating a thumb tab12,19of each of the retainer pins4,9into their respective pin retainer notches11. Safing blade3is secured by and allowed to pivot about retainer pin4and retainer bushing10through an opening5in safing blade3. Safing blade3is secured in its closed position by a latching mechanism17thereof and a latching mechanism retainer18of top cover2. Latching mechanism17is spring-loaded in its extended or locked position and is retracted by depressing a tab7. When tab7is depressed, latching mechanism17is retracted to clear latching mechanism retainer18and allowing safing blade3to be rotated to its open position.

In order to safe the gun, the safing blade3must be rotated from its closed position, as illustrated inFIG. 7, to its open position, as illustrated inFIGS. 8 and 9. The operator accomplishes this by depressing tab7and rotating safing blade3outward to its open position. When the safing blade3is fully open, a spring-loaded plunger15, incorporated in safing blade3, snaps into engagement with a plunger keeper16that is provided in top cover2. Safing blade3will remain open, and the gun will remain safed until the operator depresses plunger15to release its engagement with plunger keeper16and permit rotation of safing blade3to its closed position. Safing blade3may be locked in its closed position by first depressing tab7or by the preferred method of rapidly rotating safing blade3downward to thereby force latching mechanism17past latching mechanism retainer18.

Referring now toFIG. 10, there is shown an underside view of top cover and safing blade assembly1ofFIG. 5. The underside of safing blade3is depicted by the hatched area illustrated inFIG. 10. The geometry of forward and aft camming portions21,22of helical track20is similar to the geometry of those same elements as depicted inFIG. 4. When safing blade3is in its open position or, in other words, when the gun is safed, as illustrated inFIGS. 8 and 9, forward camming portion21of helical track20is removed from the overall length of helical track20, leaving aft camming portion22thereof in place. With the forward camming portion21of helical track20removed and the aft camming portion22retained in its operational position, the barrels of the minigun may be rotated electrically without it firing and without the bolt assemblies thereof being damaged.

In contrast to the prior art two-piece top cover30and safing sector31illustrated inFIGS. 1-4, the present invention combines the top cover30and aft camming portion22of helical track20into a single unit, top cover2ofFIGS. 5-10, allowing forward camming portion21of helical track20, which is incorporated in safing blade3, to be removed separately. Safing the gun by means of opening safing blade3requires far less time and effort than prior art safing systems. Likewise, far less time is required to transition the minigun back to its armed and ready condition. In the event it becomes necessary for the operator to remove live cartridges from the minigun without firing them, safing blade3can be locked in its open position, and the minigun barrels can be rotated electrically to thereby quickly clear the minigun of live cartridges.

To remove the top cover and safing blade assembly1from main housing8, thumb tabs12,19of retainer pins4,9, respectively, are rotated out of their pin retainer notches11and allowed to retract, under pressure exerted by locking pin spring32, from the locator holes within main housing8. This permits top cover and safing blade assembly1to be removed in its entirety from main housing8.