Patent Publication Number: US-9429376-B2

Title: Manual GAU-21 charger

Description:
CLAIM OF PRIORITY 
     This application claims priority under 35 U.S.C. Section 119(e) of U.S. Provisional Patent application Ser. No. 62/064,738 filed Oct. 16, 2014 entitled MANUAL GAU-21 CHARGER, the teachings of which are included herein in their entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure provides a manual charger mechanism for a gun, such as a GAU-21 gun. 
     BACKGROUND 
     A legacy charging design for a GAU-21 weapon does not have acceptable clearances for mounting its cradle externally on aircraft. This disclosure provides a compact charging design that allows the cradle to be mounted externally, such as on an aircraft, with adequate clearances. 
     The legacy charging design also has charging forces that are too high. This disclosure provides a design that reduces charging forces, making it easier for a user to charge the weapon. 
     SUMMARY 
     A mechanical gun charger configured to charge a gun, including a cradle configured to support a gun. A lever is rotatably coupled to the cradle, wherein an outboard cable coupled between the lever and a first pulley is configured such that displacement of the lever causes the first pulley, a shaft, and a second pulley to rotate. A charging cable is coupled to the second pulley and is configured to couple to and charge the gun upon rotation of the second pulley. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  illustrates a perspective view of a GAU-21 gun placed in a cradle having a manual charging system; 
         FIG. 2  and  FIG. 3  illustrates the manual charging system with the cables removed for clarity; 
         FIG. 4  illustrates an outboard cable that is wrapped once around a tracked perimeter of a small pulley, and then fixed to the small pulley at a point using a quick release ball swage, and a charging cable extending from a gun bolt stud of the gun, and then fixed to the large pulley at point using a quick release latch; 
         FIG. 5  illustrates a user pulling the charging handle, where the outboard cable pulls the small pulley and consequently the shaft and the large pulley, the large pulley causing the charging cable to pull the gun bolt stud of the gun rearward to charge the weapon; 
         FIG. 6  illustrates the large pulley; and 
         FIG. 7  illustrates an inner spacer assembly configured to locate the large pulley in its correct position to align with the gun&#39;s charging cable behind the gun bolt stud. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  through  FIG. 7  illustrates a manual charging system  20  configured to charge a gun  10 . The charging system  20  includes a geared pulley system which reduces the charging force to manually charge the gun  10 . 
       FIG. 1  illustrates a perspective view of a GAU-21 gun generally shown at  10  in a cradle  12  having a manual charging system generally shown at  20  according to this disclosure. 
     As shown in  FIGS. 1-5 , the charging system  20  includes a charging handle  22  having a cam  24  on one end and a lever extending from the cam  24 , a small pulley  26 , a large pulley  42 , an outboard cable  28 , and a charging cable  40  which together reduce the charging force. The outboard cable  28  and the charging cable  40  are not shown in  FIGS. 1-3  for clarity, and are shown in  FIGS. 4-5 . The small pulley  26  is rotatably mounted to the outboard left hand (LH) side of the cradle  12 . A pulley guard  52  is annularly positioned over a peripheral track of the small pulley  26 . Pulley guard  52  encompasses the small pulley  26  and keeps the outboard cable  28  from coming loose and falling off the track on small pulley  26 . 
     As shown in  FIG. 4  and  FIG. 5 , the outboard cable  28  is fastened at one end to the charging handle  22  proximate the cam  24  at thumb screw  34 , and to the small pulley  26  at point  30  using a ball swage at the other end. The outboard cable  28  is wrapped once around the small pulley  26  in a peripheral track thereof and is fixed at point  30  to the small pulley  26  in order to set the rotational direction. The small pulley  26  is secured to an outside end portion of a shaft  54  at one end of the shaft  54 , and the large pulley  42  is secured to an inside end portion at the other end of the shaft  54 , behind the gun  10 . The small pulley  26  and large pulley  42  rotate in unison in the same direction as they are fixedly coupled to the common shaft  54 . 
     The tension-adjusting thumb screw  34  on the charging handle  22  is configured to adjust the tension in the outboard cable  28  such that there is always a proper amount of tension in the outboard cable  28  and to avoid slack. A torsion spring  56  keeps the charging handle  22  in a home position ( FIG. 4 ) against a stud stop  38  when not in use. The charging handle  22  is configured to rotate approximately ⅓ turn to charge the gun  10 . 
     As shown in  FIG. 4  and  FIG. 5 , the charging cable  40  is connected to and extends from a gun bolt stud  46  of gun  10  at one end, and is fixed to the large pulley  42  at point  44  using a quick release latch  58  ( FIG. 6 ) at the other end of the charging cable  40 . The large pulley  42  is fixed to the shaft  54 . The charging cable  40  is routed into a cable housing  47  of gun  10  and is fixed to the gun bolt stud  46 . Charging cable  40  pulls gun bolt stud  46  rearward. Charging cable  40  rotates around the large pulley  42  when the charging handle  22  is pulled to charge gun  10 . 
     As shown in  FIG. 5 , by pulling the charging handle  22  clockwise (as viewed from the LH side), the outboard cable  28  pulls the small pulley  26 , and consequently the shaft  54  and large pulley  42 . Turning large pulley  42  causes the charging cable  40  to pull the gun bolt stud  46  of gun  10  rearward to charge the gun  10 .  FIG. 6  shows the large pulley  42  having the quick release latch  58  that allows the gun&#39;s charging cable  40  to be used. The latch  58  can pivot 90° and lock in place so that the end of charging cable  40  does not slide out when installed. 
     As shown in  FIG. 3  and  FIG. 7 , an inner spacer assembly  60  having an opening  63  configured to receive the shaft  54  extending therethrough, such that the assembly  60  is interposed between the small pulley  26  and the large pulley  42 . The assembly  60  is configured to precisely locate the large pulley  42  in its correct position to align with the gun&#39;s charging cable  40 . The perimeter of the large pulley  42  is linearly aligned behind the gun bolt stud  46  and the cable housing  47 , as shown in  FIG. 4  and  FIG. 5 . The assembly  60  has a ball plunger  62  that rides in a track  64  ( FIG. 6 ) on the large pulley  42 . This ball plunger  62  is intended to keep the large pulley  42  from rotating due to tension in the outboard cable  28  when the gun&#39;s charging cable  40  is not connected to the large pulley  42 . The tension from the gun&#39;s charging cable  40  is enough to offset the tension in the outboard cable  28  so there is no rotation when it is connected. 
     The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present disclosure being limited solely by the appended claims.