OPTICALLY TRACKED PROJECTILE

Abstract

A projectile, that can be tracked by optical means, is fitted with a special tracer incorporated into the projectile's trailing edge. The rearward facing special tracer is incorporated into a metal disk which is crimped to the projectile's metal jacket. The special tracer includes micro-prismatic features that reflect light at the incidence angle. Alternatively, the disk incorporates a fluorescent dye that is responsive to a laser emission. External emitted radiation is reflected or re-emitted from the trailing edge of the projectile, allowing for an external electro-optic tracking device to identify the position of the projectile in flight.

Claims

1. An ammunition projectile configured to be fired from a weapon, said projectile having an elongated circular body with side and rear surfaces and a photo-luminescent material, disposed on the rear surface, that re-emits radiation when excited by incoming radiation from a radiation source.

2. The ammunition projectile defined in claim 1, wherein said photo-luminescent material is additionally disposed on a side surface of the projectile body.

3. The ammunition projectile defined in claim 1, wherein said photo-luminescent material is a fluorescent dye.

4. The ammunition projectile defined in claim 3, wherein said fluorescent dye responds to excitation in one of the UV, visual and IR spectral bands.

5. The ammunition projectile defined in claim 3, wherein said fluorescent dye responds preferentially to the laser light illumination in a narrow frequency range.

6. The ammunition projectile defined in claim 3, wherein the fluorescent dye forms a coating on the projectile body.

7. The ammunition projectile defined in claim 3, wherein said projectile includes a protective ablative material disposed on the projectile body to protect said fluorescent dye during cartridge ignition.

8. The ammunition projectile defined in claim 7, wherein said fluorescent dye forms a coating on an inside surface of said transparent material.

9. An ammunition projectile with a full metal jacket configured to be fired from a weapon, said projectile having an elongated circular body with a rear trailing edge that incorporates a thin metal disk, said metal disk being crimped to the rear trailing edge of the projectile, said metal disk having an exterior-facing, outer metal surface fabricated from a metal that includes reflective, micro-prismatic surfaces.

10. The ammunition projectile defined in claim 9, wherein said metal disk is fabricated from a reflective nickel alloy.

11. The ammunition projectile defined in claim 9, wherein said metal disk is fabricated from a highly polished aluminum alloy.

12. The ammunition projectile defined in claim 9, wherein said metal disk is coated with a reflective chrome finish.

13. The ammunition projectile defined in claim 9, wherein said metal disk is fabricated by at least one of stamping, etching, and forming with a die that produces prismatic features.

14. The ammunition projectile defined in claim 9, wherein the outer surface of said metal disk includes a thin metal surface layer adhering to an underlying polymer sheet with prismatic features.

15. The ammunition projectile defined in claim 9, wherein said metal disk is crimped to the metal jacket at the rear trailing edge of the projectile.

16. The ammunition projectile defined in claim 15, wherein said metal disk is optimized for rearward reflectance of reflected light over a flight path of the projectile.

17. A cartridge munition comprising, in combination: a cartridge shell having a base; a projectile having a rear portion inserted into the shell and mechanically connected thereto, thereby forming a propulsion chamber within the shell, said projectile having a full metal jacket; a pyrotechnic propulsive charge disposed within the propulsion chamber; and a pyrotechnic igniter disposed in the base of the shell by means of which the propulsive charge may be ignited such that propulsive gases of the propulsive charge exert a force on the rear of the projectile when they burn, causing the projectile to be driven out of the cartridge shell when the munition is chambered in a gun, wherein the projectile has an elongated circular body with a rear-facing trailing surface, adjacent the propellant, that incorporates a retro-reflector.

18. The cartridge munition of claim 17, wherein the pyrotechnic propulsive charge comprises a composition with a balanced stoichiometric combustion producing minimal combustion residue, thereby to avoid dimming the retro-reflector.

19. A method of manufacturing an ammunition projectile having a retro-reflective rear surface, said method comprising the steps of: (a) shaping a metal jacket forming an elongated cylindrical body with a rounded nose at a front end and a trailing edge with a circular opening at a rear end, a metal jacket being formed over one or more underlying metallic materials; (b) inserting a round disk in the circular opening, thereby fully encapsulating the formed underlying metal or metals and closing the opening, said disk having an outer surface facing rearward; and (c) crimping the trailing edge of the metal body around the disk to form a substantially impervious seal.

20. The method defined in claim 18, wherein the rear-facing outer surface of the disk includes reflective, micro-prismatic surfaces forming a retro-reflector.

21. The method defined in claim 18, wherein the rear-facing outer surface of the disk is coated with a fluorescent material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG. 1A shows the impact location and dispersion for ball ammunition.

[0041] FIG. 1B depicts the impact locations and dispersion for normal energetic tracer projectiles.

[0042] FIG. 1C depicts the impact locations and dispersion for ball/tracer mix.

[0043] FIG. 2A depicts a standard cartridge housing a projectile.

[0044] FIG. 2B depicts a standard cartridge housing a projectile in cross-section.

[0045] FIG. 2C depicts a standard cartridge in a breach firing a projectile, the projectile having exited the cartridge traveling in a barrel where burning, expanding propellant gases (not depicted) propel the projectile.

[0046] FIG. 3A provides a perspective view depicting a projectile tracking device that includes an emitter 18 illuminating a light cone 20 that intersects the ballistic path of a projectile in flight 10.

[0047] FIGS. 3B and 3C provide views that further illustrate a methodology to observe and record the projectile's location with a tracking device that illuminates the projectile's path.

[0048] FIGS. 3A-3C illustrate how an external radiation emission source 18 mounted on the barrel of the weapon emitting light in a cone of illumination 20 intersects with the projectile 10, along the projectile's flight path.

[0049] FIG. 4 depicts a external view of a FMJ projectile incorporating a special tracer.

[0050] FIG. 5A depicts two views of a special tracer that is in a wafer form.

[0051] FIG. 5B depicts a view of a special tracer that is in a wafer form and a magnified view of the surface morphology of the disk.

[0052] FIG. 5C depicts a view of a special tracer that is in a wafer with a non-burning phosphorous composition optimized to re-emit laser light.

[0053] FIG. 6A is a cut-away view of a projectile with a full metal jacket (FMJ) and a special tracer.

[0054] FIG. 6B depicts the special tracer, crimped to the projectile's trailing edge forming a fully encapsulating metal jacket.

[0055] FIG. 6C is a detailed, cross-sectional view of the crimped wafer forming the trailing edge of the projectile providing the projectile with a sealed outer metal body.

[0056] FIG. 6D are two perspective views (one in cross-section) of FMJ projectile and a special tracer crimped to the trailing edge.

[0057] FIG. 7 depicts one external perspective view and three cross-sectional perspective views of an FMJ projectile, with differing internal configurations, all incorporating a special tracer in the trailing edge.

[0058] FIG. 8A depicts a perspective and rear view of a projectile with a special tracer and a magnified view of the wafer's outer surface, the outer surface including micro-prismatic facets and morphology formed into a metal.

[0059] FIGS. 8B, 8Ca and 8Cb depict variant external morphology of a special retro-reflective tracer with magnified cut-away side views in 8Ca and 8Cb.

[0060] FIG. 8D depicts side or cross-sectional views of the metal, magnified pyramid morphology with illustrated path of retro-reflected light.

[0061] FIG. 8E shows that the angle of radiation incidence and reflectance are approximately parallel with a micro-prismatic surface.

[0062] FIG. 8F depicts a projectile's attitude in fight and a corresponding micro-prismatic surface, in the special tracer, perpendicular to the flight attitude. The figure further depicts the angle of illumination incidence and reflectance that results from the micro-prismatic surface.

[0063] FIG. 9 depicts a projectile with a special tracer that includes a fluorescent dye in a medium adhering to the disk, the fluorescent dye being able to re-emit light after illumination by a laser pulse.

[0064] FIG. 10 depicts are projectile with a special tracer that incorporates a fluorescent dye in a sub-strata with a protective or ablative coating.

[0065] FIG. 11 is a graph response curve (signal return versus time in milliseconds). Incorporating fluorescent phosphorous materials into a special tracer allow the projectile to re-emit light after excitement by laser.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0066] The preferred embodiments of the present invention will now be described with reference to FIGS. 1-11 of the drawings. Identical elements in various figures are designated with the same reference numerals.

[0067] FIGS. 1A-1C respectively show a Monte Carlo simulation of 0.308 sierra ball, tracer and ball/tracer bullet mix. Tracer bullets are normally fired with a ball to tracer mix. The mean impact point of bullets with and without burning tracers is significant when firing at longer ranges. The comparative tracer and ball comparisons highlight the ballistic drawbacks associated with use of energetic tracers.

[0068] According to the invention, the trackable projectile or bullet 10 is fabricated with a full metal jacket (FMJ) 26 and incorporates a special tracer 28. The special tracer is a not energetic but is provided with special characteristics that are incorporated into a thin metal disk 28. During assembly of the projectile, the disk or wafer 28 is crimped 32 to the trailing edge of the projectile's metal jacket 26 and forming a sealed metal jacket surrounding the bullet's internal material or materials 26A. The special tracer in wafer form either reemits or reflects radiation rearward.

[0069] The special tracers 28 are crimped 32 thus forming a trailing edge of the projectile 30. When illuminated by laser light from the vicinity of a weapon, the special tracer 34 light is reflected, allowing for identification and locating of the projectile in flight. FIGS. 6A-6D depict a projectile with a special tracer. The special tracer 28 is crimped by the bullet's exterior metal jacket 26 to form a sealed metal jacket 26A surrounding the bullet's interior metal or components. The special tracer 28 is formed to include micro-prismatic structures 34 in the exterior metal surface as depicted in FIGS. 8A-8D. With reference to FIGS. 3A-3C and 8E viewed in combination, the diagrams illustrate how an external device with an emitter 18 and detector 24 illuminate the projectile's flight path 20, and light 72 reaching the disk 34 is reflected in the direction of the incident radiation by the micro-prismatic structures 68, returning the light 74 at an angle of incidence to the external optical detector 24 co-located with the emitter 18. The array of micro-prismatic structures 68 produce a conical reflectance return 74 allowing for the reflected light to be observed by a detector 24. The cone of reflected light produced by the projectile 10 provides for continued tracking of the projectile, through its ballistic flight path 22 and provides for continued tracking where the rotational variation of spin has induced projectile yaw, precession and nutation.

[0070] A partially completed projectile may be assembled with the special tracer 28, fit the rear of the projectile as depicted in FIG. 6C, and then crimped 32 to the FMJ 26 by crimping or metal forming, thus completing a fully encapsulating metal jacket 26A and retaining the special tracer 28 within the finished projectile 10.

[0071] After completing manufacture of the projectile 10, the projectile is then loaded into a cartridge case 04 that is filled with propellant 08 forming a completed projectile 02 (FIGS. 2B and 2C). The product may benefit from use of a propellant 08 with an optimized stoichiometric balance, as such propellants are known to burn and minimize reside from propellant combustion. Thus, a clean burning propellant in combination with special tracers is useful in precluding the unwanted deposition of carbonaceous residue on a special tracer's surface.

[0072] In a second embodiment the wafer includes a fluorescent material (e.g., a dye) that is responsive and re-emits light when radiated with a laser. The light re-emission 46 returns a light signal to an optical detector or 24 tracking device. When illuminated by a light from the vicinity of a weapon 18, light is re-emitted from the projectile's trailing edge 30 in the direction of the weapon. FIGS. 6A-D depict projectiles with a special tracer. The special tracer 28 is crimped by the bullets exterior metal jacket 28 to form a sealed metal jacket 28A surrounding the bullet's interior metal or components. The special tracer disk 28, 36 includes fluorescent dyes responsive to laser emission that include phosphorous. FIG. 5C depicts a special tracer that exhibits a special light response (reemission) that is crimped to a FMJ projectile 58 that, when excited by laser light, reemits radiation as identified in FIG. 11. A cartridge with this type of special tracer in the trailing edge may incorporate an ablative or protective material 36B that burns or otherwise vaporizes after cartridge ignition.

[0073] There has thus been shown and described a novel trackable ammunition projectile which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.

REFERENCE NUMBERS

[0074] 02 Cartridge. [0075] 04 Cartridge Case with primer. [0076] 06 Primer [0077] 08 Propellant. [0078] 10 Trackable Projectile (or Bullet) with a Special Tracer. [0079] 11 Barrel of a Weapon. [0080] 12 Weapon. [0081] 14 Breach (in a barrel). [0082] 16 Projectile attitude (in a flight path). [0083] 18 Emitter (Laser or LED). [0084] 20 Light Emission Cone (from an emitter near the weapon). [0085] 22 Projectile Flight Path. [0086] 24 Detector. [0087] 26 Full Metal Jacket (FMJ) of a projectile. [0088] 26A Fully encapsulating metal jacket composed of a FMJ and crimped metal tracer disk. [0089] 28 Special Tracer (prior to crimping). [0090] 28B Special Tracer Wafer with Laser Re-emitting phosphor prior to crimping. [0091] 30 Special Tracer Crimped into the Projectile by the outer metal jacket forming the surface of a projecile's trailing edge. [0092] 32 Crimp of projectile's metal jacket to position Special Tracer Wafer within the projectile. [0093] 34 Special Tracer Wafer of metal with formed with micro-prismatic surface (seen under magnification). [0094] 36A Special Tracer Wafer with a Laser Re-emitting phosphor in a sub-straight crimped into a projectile. [0095] 36B Protective Coating for a Laser Re-emitting phosphor Tracer Wafer fit the rear of a projectile. [0096] 46 Light Return form a Special Tracer. [0097] 52 Projectile with a Special Tracer and a conventional metal core. [0098] 54 Projectile with a Special Tracer and a penetrator and core (Type 1). [0099] 56 Projectile with a Special Tracer and a penetrator core (Type 2). [0100] 58 Projectile with a Special Tracer incorporating a re-emitting phosphor responsive to laser illumination. [0101] 59 Projectile with a Special Tracer with a micro-prismatic surface. [0102] 60 Micro-prismatic Retro-reflective surface morphology. [0103] 62A Top view of a 3 sided micro-prismatic pyramid. [0104] 62B Side view of a 3 sided micro-prismatic pyramid. [0105] 64 An array of 3 sided micro-prismatic pyramids. [0106] 66 A side or cut-away view (with magnification) of the special tracer wafer's micro-prismatic exterior surface. [0107] 68 An alternate design cut-away view (with magnification) of the special tracer wafer's micro-prismatic exterior surface. [0108] 70 Coincident Light Fall and Reflectance Incident Angle. [0109] 72 Incoming light falling onto the special tracer. [0110] 74 Reflected light returning to the angle of incidence. [0111] 76 Rearward conical emission dispersion producing a return reflection over a preponderance of a projectiles trajectory. [0112] 78 Rearward Special Trace's surface is perpendicular to the projectile's flight position.