Abstract:
An attachment is provided for operably connecting a shotgun to a weapons station. The shotgun includes a trigger and a butt stock. The weapons station can accommodate one of a Mk19 grenade launcher, an M2 .50 cal machine gun and an M240G machine gun. The attachment includes a trigger module, a pump grip adapter, and a gun frame. The module actuates the trigger and includes an actuator for pulling the trigger and an adapter for engaging the butt stock. The pump grip adapter includes slots for traveling pins on the weapons station to absorb recoil. The gun frame enables installation of the shotgun therein and mounts the trigger module and the adapter to the weapon station.

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described was made in the performance of official duties by one or more employees of the Department of the Navy, and thus, the invention herein may be manufactured, used or licensed by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 
    
    
     BACKGROUND 
     The invention relates generally to shotgun adapters. In particular, the invention relates to adaptation systems that enable a shotgun to be installed onto a remote weapons station. 
     A variety of small-arms-fire weapons can be installed onto a remote weapons station for infantry support. Such weapons include the Mk19 grenade launcher, M2 .50 cal machine gun, or M240G machine gun. 
     SUMMARY 
     Conventional infantry weapon adapters yield disadvantages addressed by various exemplary embodiments of the present invention. In particular, the embodied adapters provide for incorporation of a shotgun to a remote weapons station. 
     Various exemplary embodiments provide an adapter for operably connecting a shotgun to a weapons platform. The shotgun includes a body, a pump grip, a trigger and a butt stock. The weapons station can similarly accommodate one of a variety of weapons including the Mk19 grenade launcher, the M2 .50 cal machine gun, and the M240G machine gun. The adapter includes a trigger module, a pump grip adapter, a slide release mechanism, a charging linkage, and a gun frame. The module actuates the trigger and includes an actuator for pulling the trigger as well as an adapter for engaging the butt stock. 
     The pump grip adapter includes a boss and through-hole to interface with the charging linkage. The slide release mechanism allows the gun to be cycled out of sequence. The charging linkage allows the RWS to pump the gun by interfacing with the pump grip adapter and slide release mechanism. The gun frame enables installation of the shotgun therein and mounts the trigger module and the adapter to the station. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and various other features and aspects of various exemplary embodiments will be readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, in which like or similar numbers are used throughout, and in which: 
         FIG. 1A through 1C  are perspective views of a trigger assembly; 
         FIG. 2A  is a perspective view of a pump grip adapter in a first embodiment; 
         FIG. 2B  is a perspective view of a pump grip adapter in a second embodiment; 
         FIG. 3A  is an inverted perspective view of a shotgun adapter assembly; 
         FIG. 3B  is a upright perspective view of a shotgun adapter assembly with charging linkage and slide release mechanism; 
         FIGS. 4A and 4B  are perspective views of a slide release mechanism; 
         FIGS. 5A and 5B  are perspective views of a charging linkage; 
         FIGS. 6A and 6B  are perspective views of a frame that secures the adapter; and 
         FIG. 7  is a perspective view of an integrated weapons station. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. 
     Other embodiments may be utilized, and logical, mechanical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
     Various exemplary embodiments enable a Mossberg 500 or similar shotgun to be mounted in any remote weapon station (RWS) originally designed to hold a weapon, e.g., a Mk19 grenade launcher or an M2 .50 cal machine gun. The M1126 Stryker infantry carrier vehicle represents an exemplary RWS. 
     In addition to securing the weapon in position, various exemplary embodiments enable the shotgun to be fired remotely and cycled. The exemplary designs provide for quick installation and removal of the shotgun. Conventional designs lack any standard manner to mount a shotgun in a remote gun mount that were originally designed to contain the Mk19 or the M2 .50 cal. 
     The exemplary fixture can be reduced to five main parts: a Trigger Module or Assembly, a Pump Grip Adapter, a Slide Release Mechanism, a Charging Linkage and a Gun Frame.  FIGS. 1A and 1B  show isometric assembly views of the Trigger Module  100 .  FIG. 1C  shows an isometric exploded view of The Trigger Module  100  contained within a see-through housing box  110 . This box houses a solenoid  120  integrated with a base  125 , a helical spring  130 , and a linkage  140  that facilitates the remote firing of the shotgun. The spring  130  coils around a transverse rod  145 . 
     The linkage  140  connects to the solenoid  120 . The Module  100  bolts onto the rear of the shotgun using a butt stock adapter  150  in place of the standard butt stock. The adapter  150  attaches to the base  125 . A shoulder bolt  160  attaches an actuator bridge  170  to the box  110 . A mezzanine rod  165  attaches the linkage  140  to the bridge  170 . A trigger rod  175  extends across the bridge  170  to engage the shotgun&#39;s trigger. 
       FIG. 2A  shows an isometric view of a first embodiment of the Pump Grip Adapter  200 . This Adapter  200  replaces the standard plastic pump grip on the shotgun without any modifications to the weapon. The Adapter  200  includes a boss and through-hole to enable mounting on to the charging linkage. The Adapter  200  includes a housing  205  that includes a cover  210 . The housing  205  and cover  210  respectively include lower and upper slider slots  215  and  220  that extend longitudinally and transversely in parallel. 
     The Adapter  200  includes mount plates  230  and  235  for providing structural support. At the proximal and distal ends, the Adapter  200  includes an ingress  240  and an egress  245 , both substantially cylindrical for the Tube Magazine (shown in  FIG. 3A ) to extend therethrough. 
       FIG. 2B  shows an isometric view of a second embodiment of the Pump Grip Adapter  250 , which includes an ingress  260  at the proximal end and an egress  265  at the distal end. The ingress  260  inserts into the breech opening  240 , and the shotgun barrel inserts through the breech  265 . A top slot  270  provides clearance for the Adapter  250  to travel longitudinally along the shotgun barrel during recycling. The Adapter  250  includes bosses  275  and  280 , along with a through-hole  285  for connecting a charging mechanism (shown in  FIG. 5 ). 
       FIGS. 3A and 3B  show respective isometric assembly views of first and second embodiments of the Adapter Assembly  300  that enables the shotgun to be fired remotely and cycled. Viewed from above in  FIG. 3A , the first embodiment, featuring the Adapter  200 , includes distal and proximal frames  310  and  320  attaching together around the shotgun by side flanges  330 . A Tube Magazine  340  holding additional ammunition rounds passes through the Pump Grip Adapter  200 , with the ammunition loading aftward (to the right). The Tube Magazine  340  is depicted by a proximal tube portion that extends forward from the muzzle  245 , and a distal tube portion that extends aft from the breech  240 . A shotgun barrel  350  (with muzzle end pointing left) extends parallel to the Tube Magazine  340 : shown underneath in  FIG. 3A  and above in  FIG. 3B . 
     Release pins  360  enable convenient removal of the shotgun without disassembling the Adapter Assembly  300 . Viewed from below in  FIG. 3B , the second embodiment includes a Slide Release Mechanism  370  and a Charging Linkage  380 . A boss  385  connects the Adapter  200  along the slot  215  with the Charging Linkage  380  behind the shotgun&#39;s trigger on the side flanges  330 . The second embodiment also includes the distal frame  310  and a proximal frame  390  connected by side flanges  395 . 
       FIGS. 4A and 4B  show isometric assembly and exploded views  400  of the Slide Release Mechanism  370  that enables cycling of the shotgun weapon regardless of the firing sequence. A cable within a jacket  410  connects a plunger housing  420  with a release housing  430  and secures to the RWS by screw tabs  440 . The Charging Linkage  380  depresses an internal plunger within the plunger housing  420 , which in turn actuates a trigger lever  450 . Axial travel of the plunger can be adjusted by a set screw  460  that inserts into the jacket  410  and the release housing  430 . A spring within the plunger housing  420  applies force to the trigger lever  450  and to a slide release button on the shotgun. This enables the shotgun to be pumped to empty the ammunition chamber whether or not a round was fired. Threaded bolts  470  secure the trigger lever  450  to pivot within the release housing  430  to disengage the trigger rod  175  by turning laterally. A slide release plunger  480  within the slide release housing  420  is depressed though interaction with the Charging Linkage  380 . The linear motion of the plunger  480  transmits though the cable within the jacket  410  to rotate the slide release lever  450  within the release housing  430 . 
       FIGS. 5A and 5B  show isometric assembly and exploded views  500  of the Charging Linkage  380  that enables the RWS to actuate the Pump Grip Adapter  200 . A charging tray  510  mates to the Pump Grip Adapter  200 . The pin  360  connects the charging tray  510  to the charging rod  520 , which slides through an RWS interface tab  530 . A slider assembly  540  slideably attaches to an axial rod  550 . Nuts  560  and springs  570  on the rod  550  enable mechanical adjustment. The motion to operate the charging mechanism resident on the RWS transmits through the components of the Charging Linkage  380  to both release the slide and cycle the weapon. 
       FIGS. 6A and 6B  show isometric assembly and exploded views of the Frame  600  (as the second embodiment) that secures components of the Adapter  200  together for assembling in the RWS. The structure of the Frame  600  enables bolting other equipment above itself. Mountable stocks  610  and  620  (corresponding to the flanges  395 ) provide a platform for the fore housing  310  that contains the Adapter  200 . An aft housing  630  (corresponding to the frame  390 ) also connects to the stocks  610  and  620  to support the Trigger Module  100 . 
     A first tube  540  attaches to the first connector  250 , and a second tube  350  attaches to the second connector  260 . Two quick-release pins  465  enable release of the shotgun without removing the entire adapter. A linkage connects the pump action pin  580  to the RWS charging actuator. 
       FIG. 7  shows an isometric view of the RWS  700  with the Assembly  300  (that includes the Frame  600  for the Shotgun Adapter  200  and accompanying Trigger Module  100  mounted thereon). The RWS  700  includes a base platform  710  that supports additional equipment mounted onto the side  720  and on the top  730  such as antennas  740 . 
     The RWS Shotgun Adapter as an assembly  300  is implemented and operated in the following manner. 
     Replace the standard shotgun butt stock with the butt stock adapter  180 , 
     Replace the pump grip with the pump grip adapter, e.g., as shown in the first embodiment  200 , 
     Install the assembled frame  300  into remote weapon station  700  and secure with the pins  360 , 
     Attach pump action linkage to the boss  385 , 
     Attach additional equipment to the adapter  200 , 
     Install Shotgun and secure with the pins  360 , 
     Plug solenoid cable into the remote weapon station  700 , 
     Load the weapon, 
     Operate trigger to fire using RWS controls, 
     Eject spent shell using the actuator through the RWS controls, thereby completing the operation. 
     Various exemplary embodiments provide advantages in enabling a shotgun capability to be adapted to any remote gun mount that is capable of firing the Ml19 grenade launcher, the M2 .50 cal machine gun, or the M240G machine gun without any modifications being made to the mount. 
     Materials used for the initial invention are aluminum and steel. Alternative materials could be used depending on their strength characteristics. Alternative solenoids can be used as long as they meet the force and power requirements. The original design incorporated the Mossberg 500 series shotgun although other shotguns are adaptable. The equipment located on top of the adapter is specific to the original application; other equipment can be installed as required. 
     While certain features of the embodiments of the invention have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the embodiments.