Patent Publication Number: US-2015083012-A1

Title: Rear ejection impact marking ammunition assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This non-provisional patent application hereby claims priority to and the benefit of U.S. Provisional Patent Application No. 61/510,012, titled Rear Ejection Impact Marking Ammunition Assembly, filed Jul. 20, 2011, and which is incorporated herein in its entirety by reference thereto. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention are directed to ammunition, and more particularly to ammunition configured to mark an impact area, and related methods. 
     BACKGROUND 
     The United States Armed Forces uses training ammunition to provide realistic high-fidelity training to its service members. The rise in night-time visual devices has required corresponding advances in training ammunition. Typically, tracers are placed in the aft-most end of the projectiles while impact markers are placed in the fore-most end; i.e., the nose of the projectiles such that they are activated and/or dispersed upon projectile impact. This provides an impact signature visible to the gunner to help confirm whether the fire is on target, whether correction to the aim is needed and, most importantly, the direction of the correction. A major disadvantage of a nose-mounted impact marker comes from the very fact that the signature material/device is positioned in the projectile&#39;s nose; in that the projectile&#39;s body is between the impact signature and the gunner so that the projectile body can block or otherwise obscure a major portion of the impact signature. This condition is further exasperated should the projectile impact a soft target such as earth, snow, water, and the like. Under these conditions, the projectile may penetrate into the “soft” target before the impact signature material deploys, thus completely obscuring the projectile&#39;s impact from the gunner. Thus there is a need to make the impact signature visible to the gunner regardless of the nature of the target. Furthermore, the applicable tracer and impact signature materials need to be such that they do not cause range fires upon activation/ejection/deployment. 
     SUMMARY 
     The present disclosure is directed to a rear ejection impact marking ammunition assembly that overcomes drawbacks of the prior art and provide other benefits. The ammunition assembly in accordance with at least one embodiment provides a target-marking ammunition assembly fireable from a firing system toward a target. The assembly comprises a tubular body having a marking chamber disposed between opposing leading and trailing end portions. The trailing end portion has an opening therein in communication with the marking chamber. A nose ogive is attached to the leading end portion of the tubular body. A pusher is disposed in the nose ogive and is at least partially adjacent to the marking chamber. The pusher is axially moveable relative to the tubular body&#39;s trailing end portion. A signature material is disposed in the marking chamber, and an aft cover member is connected to the trailing end portion of the tubular body. The cover has an aperture therein in communication with the marking chamber and positioned to contain the signature material in the marking chamber until impact. The pusher is axially movable toward the trailing end portion and at least partially into the marking chamber to eject the signature marker from the marking chamber through the trailing end portion when the nose ogive impacts the target. The signature material marks the target upon ejection from the marking chamber after the nose ogive and pusher impact the target. 
     In another embodiment, a target-marking ammunition assembly comprises a tubular body having an interior chamber disposed between opposing leading and trailing end portions. An ejectable payload is disposed in the interior chamber, and a nose portion is attached to the leading end portion of the body. A pusher is adjacent to the nose and the leading end portion of the body. At least a portion of the pusher is adjacent to the interior chamber and is axially moveable relative to the interior chamber and the body&#39;s trailing end portion to push the payload rearwardly away from the nose. An aft cover member is connected to the trailing end portion of the tubular body and is configured to retain the payload in the body until the nose portion impacts a target. At least a portion of the aft cover is separable from the body when the pusher pushes the payload rearwardly away from the nose. The pusher is axially movable toward the trailing end portion and at least partially into the marking chamber to eject the payload from the interior out the trailing end portion when the nose impacts the target, wherein the payload ejected from the trailing end portion is configured to mark the target without being obscured by the body or the portions of the target after impact. 
     In another embodiment, a target-marking ammunition assembly, fireable from a firing device, comprises a body having an interior chamber disposed between opposing leading and trailing end portions. An ejectable payload is disposed in the marking chamber, and at least a portion of the payload is a tracer element configured to emit a traceable signature from behind the body during travel along a trajectory. A nose portion is coupled to the leading end portion of the body. A pusher is adjacent to the leading end portion of the body, and at least a portion of the pusher is adjacent to the interior chamber and being axially moveable relative to the interior chamber and the body&#39;s trailing end portion to eject the payload rearwardly through the body&#39;s trailing end portion to mark the target without the ejected payload being obscured by the body or the portions of the target after impact. An aft cover member is connected to the trailing end portion of the tubular body and is configured to retain the payload in the body until the nose portion impacts a target. The aft cover member has a window portion that provides visibility from the rear of the body to the payload in the interior chamber during travel along the trajectory. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an ammunition assembly in accordance with an embodiment of the current disclosure, along with a trajectory path  12  from a firing system, such as a gun, to an impact area at a target. 
         FIG. 2  is schematic cross-sectional view of an ammunition assembly in accordance with an embodiment of the present invention. 
         FIG. 3  is schematic cross-sectional view of an ammunition assembly in accordance with another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure describes an ammunition assembly  10  configured to mark an impact area in accordance with certain embodiments of the present invention. Several specific details of the invention are set forth in the following description and the Figures to provide a thorough understanding of certain embodiments of the invention. One skilled in the art, however, will understand that the present invention may have additional embodiments, and that other embodiments of the invention may be practiced without several of the specific features described below. 
       FIG. 1  is a schematic view of an ammunition assembly  10  in accordance with an embodiment and showing a trajectory path  12  from a firing system  14 , such as a gun  15 , to an impact area  16  at a target  18 . One embodiment of the ammunition assembly  10  shown in  FIG. 2  is a training round that would have an impact signature visible to the gunner  11  regardless of the nature of the target  18 . The illustrated ammunition assembly  10  has a projectile  100  containing signature material  22  and that provides an aft ejecting impact signature  20  ( FIG. 1 ); i.e., upon projectile impact. The signature material  22  is projected aft directly towards the gunner without projectile body and/or target obscuration. 
     In at least one configuration, the projectile  100  has a substantially tubular body  24  with a pusher  26  in the nose ogive  28  and a protective cover  30  at the projectile rear  32  with the signature material  22  between the two. The tubular projectile body  24  is fabricated of a structurally strong material such as a steel alloy, or other suitably strong material, sized to fit the barrel  34  of the firing system  14  ( FIG. 1 ), such as the gun  15 , and equipped with driving/rotating bands  36  ( FIG. 2 ), if required. The pusher  26  is fabricated of a more ductile material, such as an aluminum alloy, and is configured to be a tapered interference fit in the forward end  38  of the tubular projectile body  24 , similar to a Morse taper fit as used on machine tools. The forward end  40  of the pusher  26  could mate up to a streamlined thin-wall windscreen  42  forming the forward nose  44  of the projectile  100 . Immediately aft of the pusher  26  is the payload  46 , such as a signature material  22 , most likely contained in a selected ampoule  48  ( FIG. 3 ). Aft of the signature material ampoule  48  and forming the rear-most section of the projectile  100  is the aft cover  50 . This aft cover  50  is configured as a stepped “hat” with the smaller diameter fitting into the inner cavity  52  of the tubular projectile body  24  and abutting the aft end  54  of the signature material ampoule  48 . The larger diameter of the aft cover  50  matches the outer diameter of the tubular projectile body  24 . 
     Upon firing the ammunition assembly  10 , the propellant gases act on the large diameter of the aft cover  50 , pushing it and the rest of the projectile  100  down and out of the weapon&#39;s barrel  34 . The stepped “hat” configuration of the aft cover  50  serves to transmit the propelling force of the propellant gasses directly upon the entire projectile  100  through the tubular projectile body  24 . This action, combined with the tapered configuration/interface of the forward end of the tubular projectile body  24  and pusher  26 , prevents the premature forward or aft ejection of the signature material ampoule  48 . 
     Upon impact with the target  18 , the impact forces will collapse the thin-wall streamlined windscreen  42  allowing the pusher  26  to be acted upon by the force of target impact. This force will drive the pusher  26  into the projectile&#39;s tubular body  24 , the ductile pusher  26  swaging down as the tapered configuration/interface dictates. Should the target impact be off-axis, the ductile nature of the pusher  26  will still enable the pusher  26  to be driven into the tubular projectile body  24 . The act of the target impact forces driving the pusher  26  into the tubular projectile body  24  will cause the pusher  26  to in turn crush/rupture the signature material ampoule  48  then push it and the aft cover  50  rearward out of the tubular projectile body  24 , thus ejecting the signature material  22  (or other payload) rearward towards the gunner. As discussed above, the payload can be a signature material  22  that marks the impact area  16  ( FIG. 1 ) of the projectile  100 . 
     In other embodiments, the ammunition assembly  10  can carry other payloads within the projectile body  24  that are ejected out the rear end of the projectile  100  upon impact. For example, the payload can be an energetic material, a gas generating material, an ignition material (one which can intentionally generate sufficient heat to ignite material at the impact area  16 ), a signature-effect material, or other selected payloads. Depending upon the nature of the signature material  22 ; for example a chemiluminescent material, in one embodiment of the projectile  100  and its components, the signature material  22  could perform a tracer function prior to target impact and subsequent ejection/target impact marking functioning. 
     In another embodiment shown in  FIG. 3 , the ammunition assembly  10  is configured as a tracer round. This tracer round has a construction generally similar to the assembly of  FIG. 2 , except the aft cover (also referred to as a base plug  60 ) has a transparent or translucent window portion  62  that provide visibility from the rear of the projectile  100  into the area of the body  24  carrying at least a portion of the signature material  22 . In the illustrated embodiment, the signature material  22  includes an activateable chemiluminescent material configured to be activated by the forces at shot start, or by centrifugal forces at or near exiting the barrel  34  of the gun  15  or other firing device  14  ( FIG. 1 ). 
     In operation of at least one embodiment, the tracer ammunition assembly  10  is fired from the gun  15  ( FIG. 1 ), and the chemiluminescent material in the projectile body  24  is activated at shot start or upon exiting the gun barrel  34  so as to generate light  35  ( FIG. 1 ) within the projectile body  24 . The light is visible to the gunner through the window portion  62  of the aft cover  50  as the projectile  100  travels away from the gunner along the trajectory path  12  to the intended target  18 . The light within the projectile body  24  can be within the visible spectrum so the gunner can see the light with the naked eye. In another embodiment, the light can be in the infrared spectrum, ultraviolet, or other non-visible spectrum, such that the gunner can see the light using the appropriate vision enhancing equipment. The fact that the light is generated within the projectile body  24  and is visible from behind the ammunition round along its means that the gunner can see the tracing light, but personnel in front or to the side of the ammunition round along its trajectory path  12  will not be able to see the light within the projectile body  24 . 
     The tracer ammunition assembly  10  of the illustrated embodiment also has the pusher  26  within the projectile body  24 . When the projectile  100  impacts the target  18  ( FIG. 1 ), the pusher  26  causes the signature material  22 , such as the chemiluminescent material and/or other marking material (e.g., dye powder or the like), is ejected out the rear of the projectile body  24 . Accordingly, the ejected signature material  22  is visible to the gunner or other personnel at impact without the projectile body  24  or portions of the target  18  ( FIG. 1 ) obscuring the signature material  22 . 
     From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the invention. Additionally, aspects of the invention described in the context of particular embodiments or examples may be combined or eliminated in other embodiments. Although advantages associated with certain embodiments of the invention have been described in the context of those embodiments, other embodiments may also exhibit such advantages. Additionally, not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, the invention is not limited except as by the appended claims.