Gun mount and ejection system

An armament system for aircraft includes gun mount and ejection system for a machine gun. The gun mount and ejection system includes an ejection chute assembly including a hopper positioned intermediate the uprights of a carriage supporting the machine gun.

BACKGROUND AND SUMMARY OF THE DISCLOSURE

The present disclosure relates to weapon systems and, more particularly, to helicopter armament systems.

It is known to provide weapon systems on aircraft, including helicopters. For example, 50 caliber machine guns have been mounted on helicopters using an external store support assemblies. However, there remains a need for a system to integrate updated weapons, including the GAU-21 50 caliber machine gun, onto helicopters, including the UH-1Y. Additionally, there is a need for an effective ammunition feed system, and casing and link ejection system.

According to an illustrative embodiment of the present disclosure, a gun mount assembly for a machine gun includes a gun cradle including spaced apart side members and configured to releasably couple to a machine gun, a carriage supporting the gun cradle and including a pair of spaced apart uprights and a downwardly extending pintle, and an ejection chute assembly including a hopper having an outlet opening. The hopper is positioned intermediate the spaced apart uprights of the carriage and is supported for movement with the cradle. An ejection tube includes an upper end coupled to the outlet opening of the hopper, and an open lower end positioned below the upper end. The hopper is configured to collect spent casings and links ejected from the machine gun and convey the spent casings and links to the ejection tube through the outlet opening.

According to another illustrative embodiment of the present disclosure, a method of ejecting spent casings and links from a machine gun comprises the steps of providing an ammunition belt to a machine gun, the ammunition belt including casings interconnected by links, ejecting spent casings downwardly from the machine gun into a hopper, ejecting spent links laterally outwardly from the machine gun, passing the spent links through a link chute from the machine gun to the hopper, and passing the combined spent casings and links from the hopper downwardly through a flexible ejection tube and out through an open lower end.

DETAILED DESCRIPTION OF THE DRAWINGS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, which are described below. The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. It will be understood that no limitation of the scope of the invention is thereby intended. The invention includes any alterations and further modifications in the illustrated devices and described methods and further applications of the principles of the invention which would normally occur to one skilled in the art to which the invention relates.

Referring initially toFIGS. 1-3, a machine gun helicopter armament system10of the present disclosure supports a weapon12and is configured to be mounted to an external stores support assembly14. The support assembly14may be coupled to an enclosure13of aircraft16in a known manner. Illustratively, the aircraft16comprises a UH-1Y helicopter including left and right support assemblies14aand14bmounted to the left and right sides of the helicopter16. The enclosure13may be a crew compartment and illustratively includes a vertical mounting surface150and a horizontal floor151. The helicopter16may also include additional weapons, such as rockets18aand18b, supported by and/or adjacent to the respective support assemblies14aand14b. More particularly, the support assemblies14may each include a pair of spaced apart downwardly extending arms15supporting a cross member17which, in turn, supports rockets18. A pair of sway members19, illustratively adjustable turn buckles, extend at an angle between the arms15and the cross member17.

In the illustrative embodiment, the weapon12comprises a 50 caliber machine gun, such as a GAU-21 machine gun manufactured by FNH USA of McLean, Va. While a UH-1Y helicopter and a GAU-21 machine gun are used for illustrative purposes, it should be appreciated that other aircraft and weapons may utilize the armament system10of the present disclosure.

With reference toFIGS. 2 and 3, the armament system10illustratively includes a gun mount assembly20configured to support the machine gun12for azimuth movement (about a longitudinal (e.g. vertical) axis21) and elevational movement (about a transverse (e.g. horizontal) axis23). An ammunition canister and mounting assembly22is supported within the interior of the helicopter16and is configured to supply an ammunition belt24(FIG. 18) to the machine gun12through a feed chute26. The feed chute26couples to the firing chamber of the machine gun12in a conventional manner. The feed chute26is illustratively formed of interconnected stainless steel segments to provide flexibility and may be manufactured by Standard Armament of Glendale, Calif.

With reference toFIGS. 4-10, the gun mount assembly20illustratively includes a cradle28operably coupled to a carriage30. The machine gun12is coupled to the cradle28in a conventional manner. The cradle28includes a pair of laterally spaced apart side members29which are supported by the carriage30. More particularly, the carriage30illustratively includes a U-shaped body or yoke32having laterally spaced apart uprights34receiving the cradle28. The side members29of the cradle28are supported by a pivot coupling36, illustratively defined by opposing studs37supported by uprights34, for vertical pivoting movement (i.e., elevational or about axis23) relative to the carriage30. A base38connects the uprights34of the carriage30and is rotatably supported by a pintle40. The pintle40extends downwardly through a hollow support shaft or mounting tube42of the external stores support assembly14.

Referring now toFIG. 11, a first or upper end43of the pintle40is secured to the base38of the carriage30through fasteners44, such as screws extending through a collar45. A second or lower end46of the pintle40includes a nut48secured thereto and configured to secure the carriage30to the support assembly14. More particularly, the nut48is threadably received on a threaded lower portion47of the pintle40. A safety pin49prevents unintended loosening of the nut48by being received within slots51of nut48and passing through diametrically opposed openings53of pintle40.

With reference toFIGS. 11-14, the pintle40permits rotational movement about axis21(i.e., azimuth) of the carriage30. A pintle adapter or azimuth stop body50is supported by the mounting tube42and includes an arcuate raceway52extending between stops54and56. A stud57including a pin58extends downwardly from the base38of the carriage30and is configured to ride within the raceway52as the carriage30is rotated about the longitudinal axis. The stops54and56define the rotational limits of travel for the carriage30about axis21.

A pair of notches60and62are formed in the peripheral edge of the stop body50and are configured to alternately cooperate with a spring biased stow pin assembly64extending downwardly from the base38of the carriage30. The stow pin assembly64illustratively includes a pin63slidably received within a receiver65and spring biased downwardly in a down position (FIG. 11). A handle66is coupled to an upper end of the pin63to permit a user to raise and lower the pin63. The handle66is received within a first slot67when in a lowered position, and is received within a second slot69when in a raised position. When the pin63is lowered and received within notch60of the stop body50, the carriage30supports the machine gun12in a position substantially perpendicular to the helicopter16(FIG. 2). When the pin63is lowered and received within notch62of the stop body50, the carriage30supports the machine gun12in a stowed position substantially parallel to the helicopter16(FIG. 8).

With reference toFIGS. 15-17, a cradle elevation stop member70is secured to side member29aof the cradle28and is configured to provide discrete set points, as defined by depressions or recesses72a,72b,72cfor the elevation of the machine gun12. As shown inFIGS. 15 and 16, a spring biased toggle pin74may be set and released, through operation of a lever handle75, in position within one of the recesses72a,72b,72cto provide a desired set point for the angular orientation of the cradle28and hence the machine gun12about transverse axis23. In the illustrative embodiment, the recesses72a,72b,72care circumferentially spaced apart along an arcuate pathway76.

The ammunition canister and mounting assembly22is operably coupled to the machine gun12and includes an ammunition receptacle or canister82configured to receive a predetermined number of rounds of ammunition. In one illustrative embodiment, the canister82is configured to receive 600 rounds of ammunition forming ammunition belt24. The ammunition belt24is stored in a serpentine pattern within a storage compartment81of the canister82to facilitate feeding to the machine gun12through the feed chute26. The ammunition belt24may be of conventional design as including a plurality of rounds including a casing84receiving a bullet86, and a plurality of links88interconnecting adjacent casings84(FIG. 18). The casings84and links88are typically made of metal, such as brass.

As is known, when bullets86are fired from the machine gun12, the spent casings84and associated links88are ejected at elevated temperatures. More particularly, spent casings84generally fall from the bottom of the machine gun12while links88are generally ejected from the side of the machine gun12opposite the feed chute26. An ejection chute assembly90is provided to collect and distribute casings84and links88exiting from the machine gun12in order to reduce the likelihood of the casings84and links88from falling onto helicopter external stores, such as rockets18, or within the operator compartment of the helicopter16. More particularly, hot casings84and links88coming into contact with other stores on the helicopter16may adversely affect their operation and/or present safety concerns.

With reference toFIGS. 2-4,19and20, the ejection chute assembly90includes a hopper92including an outlet opening93coupled to a downwardly extending ejection tube94. The hopper92is illustratively formed of a durable metal, such as stainless steel or aluminum, and is received intermediate the uprights34of the carriage30and is coupled to the cradle28. Referring further toFIGS. 19 and 20, the front end of the hopper92includes an inclined deflector96extending between first and second side walls95aand95b, while an end wall97extends between the side walls95aand95bat a rear end of the hopper92. A bottom portion99extends between the side walls95aand95bintermediate the deflector96and the end wall97. The bottom portion99defines the outlet opening93for receiving spent casings84and links88.

The front end of walls95include a pair of notches98configured to receive a pin100extending laterally proximate a front end of the cradle28between side members29(FIG. 3). A collector102of the hopper92is defined between the side walls95aand95b, the deflector96, and the end wall97. A spacer tube103extends between a pair of apertures104formed within the side walls95aand95band provides additional rigidity to the hopper92. The spacer tube103is configured to slidably receive a laterally extending pin106for securing the ejection chute assembly90to the cradle28. A cotter pin105is illustratively secured to the hopper92through a lanyard107and is configured to be received within an aperture108formed within the end of pin106to secure the pin106within the spacer tube103.

The ejection chute assembly90is configured to facilitate conveyance of spent casings84and links88away from the gun12, particularly when used in connection with a gun having a high rates of fire (for example GAU-21 with potential of 1,100 shots per minute). The deflector96cooperates with the outlet opening93(FIG. 19) to facilitate discharge of the spent casings84and links88into the ejection tube94. More particularly, the deflector96is angled relative to the gun12such that spent casings84deflect or ricochet off of the deflector96, pass through the outlet opening93, and into the ejection tube94, without tending to collect or jam by bridging the opening93. The angle of deflection of the spent casings84is determined by the angle of discharge of the casings84from the gun12and the angle of the deflector96relative to the gun12. In the illustrative embodiment shown inFIG. 6, the deflector96is angled from the longitudinal axis109of the gun barrel by about 47 degrees (+/−5 degrees). As such, the angle α as shown inFIG. 20is about 47 degrees (+/−5 degrees) and the angle between the bottom portion99and the deflector96is about 133 degrees (+/−5 degrees).

As shown inFIG. 19, the ejection tube94illustratively includes a flexible portion110having an upper end coupled to a cylindrical connector111of the hopper92through a band clamp112. A bottom portion of the connector111has an enlarged, illustratively flared, portion113having an increased diameter to prevent the clamp112, and hence the tube94, from slipping off of the hopper92. An end sleeve114defines a lower open end116of the ejection tube94and is coupled to the flexible portion110through fasteners, such as grommets118. The flexible portion110is illustratively formed of a heat and flame resistant material. In one illustrative embodiment, the flexible portion110is formed of CEET ducting, including a support formed of a copper coated or bronze plated spring steel wire helix, a liner and a cover formed of woven fiberglass fabric impregnated and coated with neoprene rubber, and a fiberglass cord impregnated with neoprene rubber supported outside of the cover. The end sleeve114may comprise a heat shrinkable insulation sleeving that is configured to prevent damaging contact with the lower end of the flexible portion110and fraying thereof.

A securing device120illustratively secures the ejection tube94to the support18. The securing device120may comprise a releasable clip122coupled to a ring124which, in turn, is secured to the flexible portion110of the ejection tube94by a band clamp126. The clip122coupled to one of the sway members19of the support18to restrict movement of the ejection tube94(FIG. 2).

An upper opening128of the hopper92collects the ejected casings84and directs them to the tube94. Similarly, first and second ports or receivers130are supported by opposing side walls95of the hopper92and collect the ejected links88and direct them to the tube94. As noted above, the links88are generally ejected from the side of machine gun12opposite the feed chute26. As such, a link chute132is coupled to the receiver130opposite the feed chute26(FIG. 2). The opposing receivers130provides flexibility for coupling link chute132to opposing sides of the machine gun12depending upon the orientation thereof (for example, left or right side of the helicopter16). In other words, the link chute132may be positioned on either side of the machine gun12, opposite the feed chute26. The link chute132is illustratively formed of interconnected stainless steel segments to provide flexibility and may be manufactured by Standard Armament of Glendale, Calif.

In operation, ejected casings84drop through the upper opening128of the hopper92, while links88pass through the link chute132and through the receiver130of the hopper92. The casings84and links88pass through the collector102and down through the ejection tube94. The ejection tube94directs the ejected casings84and links88away from the helicopter16. Combining the casings84and links88in the hopper92reduces space requirements and reduces operational issues with the machine gun12. More particularly, the ejection chute assembly90facilitates ejection of casings84and links88associate with weapons operating at high rates of speed (for example, at the GAU-21 machine gun).

With reference toFIGS. 2-5and21, the ammunition canister82is configured to be releasably coupled to the interior of the helicopter16through a mounting assembly144. As shown inFIGS. 22 and 23, the canister82illustratively includes a first side wall134, and a second side wall136extending parallel to the first side wall134. A first end wall138extends between the first side wall134and the second side wall136. A second end wall140extends between the first side wall134and the second side wall136in spaced relation to the first end wall138. The storage compartment81is defined by the walls134,136,138, and140and is accessible through an open upper end142.

Referring now toFIGS. 22,24, and25, the mounting assembly144includes a pair of first mounting members, illustratively a first or left receiver146and a second or right receiver148supported by a vertical mounting surface150. The mounting surface150may comprise the longitudinally extending transmission wall of the helicopter16. The receivers146and148each illustratively include a first or lower coupler152aand a second or upper coupler152bsupported by a base153secured to mounting surface150. With reference toFIGS. 24 and 25, each coupler152aand152billustratively includes a C-shaped bracket154having an upper arm156and a lower arm158defining an end bracket receiving opening160. A resilient pad161, illustratively a polyurethane foam, may be supported by the base153and provides a cushion between the canister82and the mounting surface150.

Referring further toFIGS. 22 and 23, a pair of second mounting members, illustratively a first or left end bracket162and a second or right end bracket164are secured to opposing first and second end walls138and140, respectively, of the canister82. Each bracket162,164includes laterally spaced apart openings166aand166b(FIG. 23). The first end bracket162is configured to be releasably coupled to the first receiver146, and the second end bracket164is configured to be releasably coupled to the second receiver148. More particularly, a first pin170is illustratively slidably received by the first end bracket162and the lower coupler152aof first receiver146, while a second pin172is illustratively slidably received by the second end bracket164and the lower coupler152aof the second receiver148.

As shown inFIG. 22, the arms156and158of the brackets154each include upper and lower bushings171and173, respectively, configured to slidably receive one of the pins170and172. Each pin includes a spring biased ball174configured to engage respective bushing171,173as the pin170,172is moved axially therethrough.

A third pin176is illustratively slidably received by the upper coupler152bof the first receiver146, while a fourth pin178is illustratively slidably received by the upper coupler152bof the second receiver148. The pins170,172,176,178are secured to the respective bases153by lanyards180.

The combination of lower coupler152aand upper coupler152bfor each receiver146and148facilitates mounting of different size ammunition canisters to the mounting surface120. In the illustrative embodiment, the receiver146and148may be utilized to mount either GAU-21 or GAU-17 ammunition canisters. The upper couplers152bprovide additional flexibility in mounting canisters82of varying sizes (for example, to accommodate different types, sizes, and amounts of ammunition). For example, canister82ofFIG. 22includes only single brackets162and164on each end wall138and140, while larger canisters82may be taller and have a second set of brackets (not shown) above the brackets162and164for coupling with couplers152b.

The left and right end brackets162and164are mirror images of each other to facilitate mounting of the canister82on either side of the helicopter16. In other words, the canister may be coupled with the first side wall134facing the mounting surface150in a first orientation, and may be coupled with the second side wall134facing the mounting surface150in a second orientation (i.e., rotated 180 degrees about a vertical axis).

With reference toFIGS. 26-28, the ammunition canister82also includes a lid182coupled to second side wall136by a hinge184to cover at least a portion of open upper end142. A latch186is supported opposite the hinge184and is configured to engage a catch188supported by the first side wall134.

As shown inFIG. 22, a first outlet opening190is defined between the lid182and the first end wall138, while a second outlet opening192is defined between the lid182and the second end wall140. The ammunition feed chute26may be operably coupled to the canister82above the first outlet opening190in the first orientation of the canister82(FIG. 21), and may be operably coupled to the canister82above the second outlet opening192in the second orientation of the canister82. A first pair of feed chute catches194are supported by the first and second side walls134and136adjacent the first outlet opening190, and a second pair of feed chute catches196are supported by the first and second side walls134and136adjacent the second outlet opening192. Rollers198are provided on opposing sides of the lid182to facilitate feeding of the ammunition belt24from the canister82through the feed chute26.

The ammunition feed chute26extends from the outlet opening190,192of the ammunition canister82to a receiver chamber199of the gun12. The canister82is mounted adjacent the vertical mounting surface150and the floor151to minimize the consumption of usable space within the enclosure13, and to ensure sufficient positioning of the feed chute26so it limits restrictions on movement of the ammunition belt24through the feed chute26over the full range of movement of the gun12. The outlet opening190,192of the ammunition canister82is illustratively positioned below the receiver chamber199of the gun12to reduce the bending of the feed chute26therebetween and limit the drag on the ammunition belt24traveling through the feed chute26.

With reference toFIGS. 26 and 27, end walls138and140of the canister82include sights200such that ammunition belt24remaining in the storage compartment81of canister82is visible. As such, the operator can view how much ammunition is remaining or needs to be added. Illustratively, the sight200comprises a pair of upper vertical slots202formed in the first and second end walls138and140above the respective end brackets162and164, and a pair of lower vertical slots204formed in the first and second end walls138and140below the respective end brackets162and164.