Abstract:
A flameless tracer/marker provides heat mark chemicals with optional chemlucents chemicals that can be carried and delivered by a projectile to mark a target. This marking payload may be carried by small, medium and large caliber projectiles that are part of ammunition items including 20 and 40 mm grenade launched, 90 mm, 105 and 120 mm tank, 60, 81 and 120 mm mortar and 105 and 155 artillery ammunition. This ammunition is gun launched and the projectiles can provide a heat trace to the target and/or upon impact with the target the projectile breaks or shatters and leaves a heat signature on the target for up to several hours. Included with these heat chemicals may be optional chemlucents. This heat mark may be placed into a lethal and non-lethal projectile. This allows heavy and light armor targets, vehicles, buildings and personnel to be marked without extensive damage to the target and without seriously injuring a person. The target may now be heat marked and chemlucent marked.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims benefit under 35 USC 119(e) of provisional application 60/481,529, filed 21 Oct. 2003, the entire file wrapper contents of which provisional application are herein incorporated by reference as though fully set forth at length. 

   FEDERAL RESEARCH STATEMENT 
   The inventions described herein may be manufactured, used, and licensed by, or for the U.S. Government for U.S. Government purposes. 
   BACKGROUND OF INVENTION 
   1. Field of the Invention 
   This invention relates to munitions employed for training and tactical purposes. More particularly, the present invention relates to small arms, mortar and canon caliber munitions comprising a heat mark or signature including optional IR or visible chemlucent chemicals that can be seen by thermal and/or night vision devices (NVD) used by the U.S. military and their allies either during flight as a projectile tracer or delivered to a target for marking. 
   2. Background of the Invention 
   In both military and non-military organizations, training and tactical exercises commonly employ standard ammunition items such as 40 mm, tank, artillery, and mortar munitions. Projectiles such as these commonly carry explosives, pyrotechnics, chemiluminescents, and florescent powders. Explosives are used to defeat or destroy targets. Pyrotechnics are used to light a battlefield or provide a trace of the projectile flight. Chemiluminescents (reference is made to U.S. Pat. No. 6,497,181) can be used to mark a target in low light conditions in visible and IR light without any flame source and little heat output. Chemiluminescents may also be used to provide a trace of the projectile flight, as also taught in said U.S. Pat. No. 6,497,181. Florescent powders are used to mark a target during the day to show target impact location. As further used in this specification, the term “chemlucent” or “chemilucent” shall refer to chemiluminescent chemicals, such as are referred to in said U.S. Pat. No. 6,497,181 and other examples as later described in this specification such as in paragraphs [Para 23], [Para 24], [Para 28], [Para 34]. [Para 39], and [Para 40]. The lower case “chemlucent” and “chemilucent” are generally preferred to be used in this specification in place of the upper case words “CHEMLUCENT” and “CHEMILUCENT”, and done further to avoid possible confusion to ChemLucent™ &amp; ChemiLucent™, which are registered marks of CHEMICON International Company, Temecula, Calif. The latter deal with chemicals having peroxide solutions other than what are generally described in this specification. 
   Although this technology has proven to be useful, it would be desirable to present additional improvements. What is needed is a projectile that can mark a target with both heat and chemlucents or just heat. This marking may be visible during the day or night when viewed with thermal and/or night vision devices (NVD). The need for such a system has heretofore remained unsatisfied. 
   SUMMARY OF INVENTION 
   The present invention satisfies this need, and presents a system and an associated method (collectively referred to herein as “the system” or “the present system”) for marking a target with heat and optional chemlucents using small, medium and large caliber ammunition. 
   Targets marked with a heat mark or signature that may comprise optional IR or visible chemlucents can be seen by thermal and/or night vision devices (NVD) used by the U.S. military and their allies. The present system provides a heat mark chemicals with optional chemlucents chemicals that can be carried and delivered by a projectile to mark a target. This marking payload may be carried by small, medium and large caliber projectiles that are part of ammunition items including 20 and 40 mm grenade launched, 90 mm, 105 and 120 mm Tank, 60, 81 and 120 mm mortar and 105 and 155 artillery ammunition. This ammunition is gun launched. The projectiles can optionally provide a heat trace to the target. These projectiles are loaded into their appropriate cartridges using conventional components. 
   Upon impact with the target, the projectile breaks or shatters and leaves a heat signature on the target for up to several hours. Included with these heat chemicals may be optional chemlucents taught in U.S. Pat. No. 6,497,181. This heat mark may be placed into a lethal and non-lethal projectile. The present system allows heavy and light armor targets, vehicles, buildings and personnel to be marked without extensive damage to the target and without seriously injuring a person. The target may now be heat marked and chemlucent (optional) marked. 
   Tracer/marker projectiles are chambered in and fired from a gun in the same manner as all other ammunition. When fired, the primer is set off and the gases from the primer propel the projectile down the gun tube. The force exerted on the projectile as it begins to move is called the set-back force. The set-back force breaks the vials and/or bags of heat and optional chemlucent chemicals in the projectile. The heat and optional chemlucent chemicals mix and emit heat and light (optional). The optional chemlucents may emit IR or visible light, depending on the formulation of the chemlucent chemical. 
   The projectile continues down the tube and engages the rifling, which spins up the projectile. If the projectile is launched in a smooth bore gun tube, a canted fin imparts the spin to the projectile during flight. The heat chemicals and optional chemlucent chemicals become well mixed during flight and emit heat and light (optional). If the windshield or projectile is transparent or translucent, the optional chemlucent light provides a trace of the flight path to the target. The observer can follow the projectile flight by eye or NVD or heat vision equipment. If the projectile is opaque, the observer will not see any light emitted by the projectile during flight. 
   The projectile is typically made of plastic or composites in at least the front end of the projectile. Upon projectile impact with the target, the projectile shatters and deposits the heat chemical and chemlucent chemical (optional) on the targets. The target is now marked with heat for several hours. Optional chemlucents included in the projectile can emit IR or visible light. 
   Common to industry are conventional chemicals which, when mixed with liquids such as water or salt water will generate heat. Powdered metals (i.e., iron, aluminum etc.), when mixed with water or salt water will generate heat. Other chemicals, such as salts (i.e., calcium chloride or sodium acetate) when mixed with water or salt water will generate heat. Other chemicals may be used in the heat mark, i.e., Hydroxyethyl cellulose (HEC) as a thickening agent to control the thickness of the slurry so that it sticks better on the target. Silicone can be added to the mixture to also help the heat mark to stick to the target but will also serve as an insulator to prevent the heat from being drawn-off by target materials such as metals. The silicone can also make bag materials (optional) stick to intended targets. The silicone and HEC can therefore allow the heat mark to last a long time on the intended targets. Propylene glycol or other antifreeze agents may be added to the water to prevent freezing in cold locations. 
   In an embodiment, the heat chemicals and optional chemlucent chemicals may be contained in bags in the projectile. These bags are designed to not break on target impact, remaining intact on the target and providing the desired target mark. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The various features of the present invention and the manner of attaining them will be described in greater detail with reference to the following description, claims, and drawings, wherein reference numerals are reused, where appropriate, to indicate a correspondence between the referenced items, and wherein: 
       FIG. 1  is comprised of  FIGS. 1A and 1B  and represents a cutaway view of a 40 mm projectile showing the location of heat marking chemicals in bags suspended in silicone liquid or gel and the location of a transparent or translucent or opaque plastic or composite windshield; 
       FIG. 2  is comprised of  FIGS. 2A and 2B  and represents a cutaway view of a 40 mm projectile showing the location of heat marking chemicals in bags and chemlucent materials in bags suspended in silicone liquid or gel and the location of a transparent or translucent or opaque plastic or composite windshield; 
       FIG. 3  is a cutaway view of a 40 mm projectile showing the location of heat marking chemicals in vials suspended in a plastic spider; 
       FIG. 4  is a cutaway view of a 40 mm projectile showing the location of heat marking chemicals in vials and chemlucent material in vials suspended in a plastic spider; 
       FIG. 5  is a cutaway view of a mortar projectile showing locations for heat marking chemical in bags and optional chemlucent material in bags suspended in silicone liquid or gel; and 
       FIG. 6  is a cutaway view of a large caliber tank or artillery projectile showing locations for heat marking chemical in bags and optional chemlucent material in bags suspended in silicone liquid or gel. 
   

   DETAILED DESCRIPTION 
     FIG. 1  ( FIGS. 1A ,  1 B) is a diagram of a 40 mm projectile  100  (projectile  100 ).  FIG. 1A  is a cut-away exploded view of projectile  100 . Projectile  100  comprises a windshield  105  and a back end  110 . Windshield  105  may be transparent or translucent and comprises polypropylene. In an embodiment, windshield  105  is opaque. In still another embodiment, the windshield  105  is made of non-heat conducting materials, or painted with non-heat conducting paint, or lined on the inside of the windshield with a non-heat conducting liner (not shown). The back end  110  comprises zinc. Heat chemicals  115  comprising calcium chloride and thickener hydroxyethyl cellulose, or cellulose acetate butyrate, are contained in bag  120 . Bag  120  is comprised of low-density polyethylene. In an alternate embodiment, powdered metals or sodium acetate are used with the calcium chloride in  115 . 
   Liquid  125  comprising hydrogen peroxide and salt water possibly with propylene glycol are contained in bag  130 . Bag  130  comprises polyester. Bag  120  and bag  130  are contained in containment bag  135 . Containment bag  135  comprises 100 gauge nylon. During gun launch of projectile  100 , bag  120 , and bag  130  breaks, mixing liquid  125  with heat chemical  115 . Containment bag  135  is designed to break on target impact by projectile  100 . In an embodiment, containment bag  135  is designed to remain intact on target impact by projectile  100 . 
     FIG. 1B  is a cut-away view of projectile  100  showing the placement of containment bag  135  in projectile  100 . Projectile  100  also comprises a silicone liquid or gel  140 . The silicone  140  is used as a insulating agent as well as providing a sticky substance to help the heat mark or bag to stick to the target. In an embodiment, chemlucent chemicals in separate bags may also be placed in bag  130  or in projectile  100 . 
     FIG. 2  ( FIGS. 2A ,  2 B) is a diagram of a 40 mm projectile  200  (projectile  200 ).  FIG. 2A  is a cut-away exploded view of projectile  200 . Projectile  200  comprises windshield  105  and back end  110 . Liquid  125  is contained in bag  130 . Optional chemlucent chemical  1 ,  205 , is contained in bag  210 . Optional chemlucent chemical  2 ,  215 , is contained in bag  220 . Optional silicone gel  140  is contained in bag  225 . Chemlucent chemical  1 ,  205 , and chemlucent chemical  2 ,  215 , are collectively referenced as chemlucent chemicals  230 . 
     FIG. 2B  is a cut-away view of projectile  200  showing placement of bags  130 ,  210 ,  220 ,  225  and heat chemicals  115  inside projectile  200 . Heat chemicals  115  are placed in projectile  200  with bag  120 . In an embodiment, optional bags  210 ,  220 , and  225  are also placed in projectile  200 . During gun launch of projectile  200 , bag  130  and  120  breaks, mixing liquid  125  with heat chemical  115 . In an embodiment, optional bags  210 ,  220 , and  225  also break during gun launch, mixing liquid  125 , chemlucent chemicals  230 , and silicone liquid or gel  140  with heat chemical  115 . In an alternate embodiment powdered metals or sodium acetate or other salts may be used with or in place of calcium chloride in  115 . 
     FIG. 3  is a diagram of a 40 mm projectile  300  (projectile  300 ) showing a cutaway view of projectile  300 . Projectile  300  comprises windshield  105  and back end  110 . A gel  305  is placed in one or more sealed glass vials  310 . Gel  305  comprises water, propylene glycol, salt NaCl and hydroxyethyl cellulose. Glass vials  310  are commonly manufactured in industry by melting the ends of glass tubes. Glass vials  310  are surrounded by heat chemicals  315  comprising calcium chloride, or sodium acetate. The glass vials  310  are held apart by a plastic piece, termed a composite spider  320 . The glass vials  310  slide into and are held apart by holes in the spider  320 . Some of the glass vials  310  are filled with silicone liquid and gel  140 . In another embodiment, the glass vials  310  are placed directly into the heat chemicals  315 . 
     FIG. 4  is a diagram of a 40 mm projectile  400  (projectile  400 ) showing a cut-away view of projectile  400 . Projectile  400  comprises windshield  105  and back end  110 . Gel  305  is placed in sealed glass vials  310 . Optional chemlucent chemical  1 ,  205 , and chemlucent chemical  2 ,  215 , are placed in separate glass vials  310 . Glass vials  310  are surrounded by heat chemicals  315  comprising, for example, calcium chloride, and/or sodium acetate, and/or other salts and/or thickening agents such as hydroxyethyl cellulose. The glass vials  310  are held apart by a plastic or composite spider  320 . The glass vials  310  slide into and are held apart by holes in the spider  320 . In an embodiment, silicone liquid or gel  140  is placed in some of the glass vials  310 . In another embodiment, the glass vials  310  may be placed directly into the heat chemicals  315 . 
   During gun launch of projectiles  300 ,  400 , the glass vials  310  break, mixing gel  305 , chemlucent chemicals  230 , heat chemicals  315 , and silicone liquid or gel  140 . Upon impact with the target, projectile  300 ,  400  windshields  105  break, scattering this mixture over the target. 
   The method of assembling heat chemicals  115 ,  315 , chemlucent chemicals  230 , silicone liquid or gel  140 , gel  305 , and liquids  125  as presented in  FIGS. 1 ,  2 ,  3 , and  4  for a 40 mm projectile may be applied to any small, medium, or large caliber size projectile. Assembly of these all these projectiles is done by placing the aforementioned chemicals into the windshield  105  and then attaching the windshield to the back end  110  by thread (not shown) and/or epoxy (not shown). 
     FIG. 5  is a diagram of a mortar projectile  500  (projectile  500 ) showing a cut-away view of projectile  500 . Heat chemicals  115  are contained in bag  120 . Bag  120  may be comprised of low-density polyethylene. Liquid  125  is contained in bag  130 . Bag  130  comprises, for example, polyester. Bag  120  and bag  130  are contained in containment bag  135 . Containment bag  135  comprises, for example, 100 gauge nylon. Projectile  500  also comprises a silicone liquid or gel  140 . In an embodiment, chemlucent chemicals in separate bags may also be placed in containment bag  135 . During gun launch of projectile  500 , bag  120  and bag  130  break, mixing liquid  125  with heat chemical  115 . Containment bag  135  is designed to break on target impact by projectile  500 . In an embodiment, containment bag  135  is designed to remain intact on target impact by projectile  500 . 
     FIG. 6  is a diagram of an artillery or tank projectile  600  (projectile  600 ) showing a cut-away view of projectile  600 . Heat chemicals  115  are contained in bag  120 . Bag  120  may be comprised of low-density polyethylene. Liquid  125  is contained in bag  130 . Bag  130  comprises, for example, polyester. Bag  120  and bag  130  are contained in containment bag  135 . Containment bag  135  comprises, for example, 100 gauge nylon. Projectile  600  also comprises a silicone liquid or gel  140 . In an embodiment, chemlucent chemicals in separate bags may also be placed in containment bag  135 . During gun launch of projectile  600 , bag  120 , and bag  130  break, mixing liquid  125  with heat chemical  115 . Containment bag  135  is designed to break on target impact by projectile  600 . In an embodiment, containment bag  135  is designed to remain intact on target impact by projectile  600 . 
   The mortar projectile  500  and tank and artillery projectiles  600  may utilize the same alternate embodiments as shown for the 40 mm projectile  100 ,  200 ,  300 ,  400  in  FIGS. 1 ,  2 ,  3 , and  4 . In addition, heat chemicals  115 ,  315  and optional chemlucent chemicals  230  may be placed into any non-lethal projectile. The projectiles  100 ,  200 ,  300 ,  400 ,  500 , and  600  are assembled as depicted in  FIGS. 1 ,  2 ,  3 ,  4 ,  5 , and  6  and are then loaded into cartridges. The cartridges consist of a cartridge case, primer with a propellant system and the projectile. All these parts are common to the ammunition industry and assembled in accordance with the industry standard. The assembled cartridge is chambered in a gun in a manner similar to all other ammunition that is fired from a gun. The chamber is closed and the cartridge is fired in the same manner as all other ammunition. 
   When the gun is fired, a primer/propellant is ignited. The gases from the primer/propellant propel the projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600  down the gun tube. The force exerted on the projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600  as it begins to move is the set-back force. The setback force breaks the vials  310  or bags  120 ,  130 ,  135 ,  210 ,  220  in the projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600 . The heat chemicals  115 ,  315  mix and emit heat. In an embodiment, optional chemlucent chemicals  230  mix and emit light. If the optional chemlucent chemicals  230  are of IR formulation, IR light is emitted. If the optional chemlucent chemicals  230  are of visible formulation, visible light is emitted. 
   The projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600  continues down the tube and engages rifling, which spins the projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600 . If fired in a smooth bore gun tube, the the projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600  acquires spin during flight from a canted fin (not shown). Because of the spin, the heat chemicals  115 ,  315  become well mixed and emit heat. In an embodiment, optional chemlucent chemicals  230  become well mixed and emit light. 
   In one embodiment, projectile  500  or  600  comprises a windshield  105  and a back end  150 . Windshield  105  may be transparent or translucent and comprise, for example, polypropylene or polyethylene. In another embodiment, windshield  105  is opaque. In still another embodiment, the windshield  105  is made of non-heat conducting materials or painted with non-heat conducting paint or lined on the inside of the windshield with a non-heat conducting liner. The back end  150  of projectile  500  or  600  may be made of steel, aluminum or a transparent or translucent or opaque plastic or composite material. 
   For all projectiles  100 ,  200 ,  300 ,  400 ,  500  and  600  shown in  FIGS. 1–6 , the material of the windshield  105  and/or the material of the back end  110  or  150  are made of a material to accomplish the need or requirement of the user. If the user requires a heat trace of the projectile flight to the target as well as a mark on the target then the windshield  105  and/or the back end  110  or  150  can be made of a material that conducts heat and will break upon target impact to deposit the heat mark on the target. It is not necessary that the back end  110  or  150  breaks only that the windshield  105  breaks. 
   If the user requires a heat trace and a light trace from the optional chemlucents then in addition to the windshield  105  being made of a heat conducting material it must also be transparent or translucent to allow the light to pass through. If the user requirement is to have mark on the target only with no trace of the projectile flight then the windshield  105  and back end  110  or  150  must be opaque (to prevent light passage, only if optional chemlucents are used) and/or made of a material that does not conduct heat. A paint or inner liner to prevent the heat from coming through the windshield  105  or back end  110  or  150  may also be used to prevent a heat trace or light trace of the projectile flight to the target. 
   The heat conducting windshield  105  or back end  110  or  150  of projectiles  100 ,  200 ,  360 ,  400 ,  500 , and  600  allows heat emitted by heat chemicals  115 ,  315  to be visible to an observer, providing a trace of the flight path to the target using NVD or heat vision equipment. In an embodiment, light emitted by optional chemlucent chemicals  230  is visible to an observer through a transparent or translucent windshield  105  or back end  110  or  150 . If the windshield  105  or back end  110  or  150  of projectile is opaque, the observer does not see any light emitted by the projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600  during flight. Likewise, if the windshield  105  and back end  110  or  150  is opaque and does not conduct heat then no heat or light trace of the projectile flight will be seen, only a mark on the target will be seen after the windshield  110  breaks and deposits the heat chemicals on target. 
   Projectiles  100 ,  200 ,  300 ,  400 ,  500 ,  600  typically comprise plastic or composites in at least the front end (windshield  105 ). Upon impact with the target, the projectile  100 ,  200 ,  300 ,  400 ,  500 ,  600 , windshield  105  shatters and deposits the heat chemical  115 ,  315  and optional chemlucent chemical  230  on the targets. The target is now marked with heat for a time on the order of minutes to several hours depending on the formulation mixture. In an embodiment, the target is also marked with optional chemlucent chemicals  230  that emit IR or visible light. In a further embodiment, containment bag  135  is designed to remain intact when projectiles  100 ,  200 ,  300 ,  400 ,  500 ,  600  impact the target. Containment bag  135  remains intact and stays on the target while emitting the desired heat or light mark. 
   All drawings are illustrative in nature and do not depict the actual size or scale of the objects shown. It is to be understood that the specific embodiments of the invention that have been described are merely illustrative of certain applications of the principle of the present invention. Numerous modifications may be made to a system and method for a flameless marker/tracer utilizing heat marking chemicals as described herein, without departing from the spirit and scope of the present invention.