Abstract:
A less lethal projectile to be fired from a launcher comprising a body having a concentric cavity to hold a fluid payload, a nose cap attached to the body, said nose cap having a plurality of slits therein, which will spread open upon impact, allowing the fluid to escape.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Kinetic energy impact less-lethal projectiles have been in use for over 30 years. The early less-lethal projectiles were square cloth bags or sacks filled with No. 9 lead shot. There were two sizes, a 12-ga. Shotgun round containing 40 grams of lead shot and a 37 mm size containing 150 grams of lead shot. These projectiles were fired at a muzzle velocity of 230 and 300 feet per second (fps), for the shotgun, and from 110 to 250 feet per second (depending on the range) for the 37 mm rounds. The muzzle kinetic energy was about 70 and 120 ft-lbs, for the shotgun and from 70 to over 320 ft-lbs for the 37 mm projectiles.  
         [0002]     These projectiles were widely used by the law enforcement community after it was demonstrated by experiment that the energy delivered by the impact was below the level determined to be lethal by blunt trauma impact to the heart area. The bags were rolled up inside the shotshell of the 12 ga. Shotgun, and they unroll at about 20 feet from the muzzle. When the bags impacted at less than the unrolling distance, the area of contact was reduced to less than 1 inch, thus raising the energy per unit area to the point where the bag would penetrate into the body causing serious damage.  
         [0003]     In the late 1990 a new form of bag was introduced. The “sock bag” as it became known, was fabricated from a coarsely woven fabric in the shape of a tube, hence the name, and filled with # 9 lead shot and tied with a string to form the bag leaving a tail to act as an stabilizer. These bags suffered from the same problem as the rolled-up square bags, when impacting at 20 feet range, the kinetic energy density was about 220 ft-lbs/square inch with some expansion and if fully expanded the kinetic energy density was about 160 ft-lbs/sq in. when launched at 300 fps. In comparison a square bag at the same velocity would have a kinetic energy density of about 66 ft-lbs/sq in, when fully expanded and launched at 300 fps. The kinetic energy density goes up to over 230 ft-lbs/sq. in. when the bag strikes the target while still rolled up.  
         [0004]     A subsequent development introduced a foam projectile fired from a 40 mm launcher. This design abandoned the 12 gauge size in favor of the larger diameter impact area available from the larger diameter projectiles. The increased area of impact lowers the energy density and the compression of the foam nose lowers the sharpness of the impulse transmitted to the target individual at impact. A sharp impulse is more deleterious to tissue than a softer one.  
       SUMMARY OF THE INVENTION  
       [0005]     The projectile of this invention consists of three principal parts: the body, the nose cap and an internal payload. The projectile is fired from a conventional 40 mm (or 37 mm in another embodiment) launcher using a conventional 40 mm (or 37 mm) cartridge. The body is made from a plastic (such as polyethylene) with an integral rotating band molded in. Other similar plastics can be utilized. The body has a concentric cavity that holds a liquid payload. The liquid is captured in the body by a frangible disk, made of plastic or cardboard, that obturates the cavity. The nose cap consists of a thin polyethylene shell with a plurality of slits partially cut on the front and side of the cap. This shell has a flat front end with rounded corners where it meets the cylindrical body. The nose cap collapses at impact and the slits cut in the side open up and remain open, forming a triangular (or rhomboidal) opening. The nose cap retains this deformation. This deformation also increases the diameter of the projectile to about 2.5 inches (as measured from clay impacts), which lowers the energy per unit area to the desired level (less than about 90 ft-lbs/sq in). In an alternate embodiment a polyethylene endoskeleton of the same shape as the nose cap, but of smaller diameter, is covered with a thin rubber cap with matching slits to the polyethylene cap. The endoskeleton opens the set of slits and holds them open permanently. The rubber cap or overlay is designed to lessen the impact and effect on bare skin.  
         [0006]     The inertia of fluid that is encapsulated inside the body forces open (ruptures) the obturating disk at impact. The fluid continues moving forward and impinges on the inside of the nose cap and it is forced out radially through the open slits on the side of the cylindrical body. If the fluid contains a dye, the target individual will be marked for future identification and arrest, if warranted. Following standard practices, an irritant, such as OC (oleoresin Capsicum) or pepper extract, or CS or other tear gas solutions can be added to the fluid in the projectile to be dispersed at impact.  
         [0007]     The fluid is a mixture of constituents that is adjusted to have a density of about 2. The basic fluid is glycerin but Vaseline or other similar fluid bases can be used as well. The density augmenting fluid used was barium sulfate, but other mixtures can be used, such as ferric oxide, copper powder or other heavy inorganic materials. The viscosity should be about the range of about 2000 to 500 centipoise. This level of viscosity is important in preventing the fluid from spinning inside the spinning projectile. If the fluid attains a sufficient level of spin it will de-stabilize the projectile causing it to tumble. Longitudinal vanes can be inserted inside the projectile body to reduce any fluid spin at the lower end of the usable viscosity.  
         [0008]     The fluid mixture can be adjusted depending upon the desired application. The fluid mixture can be considerably less dense to utilize the projectile as a marking mechanism for structures, such as houses or buildings.  
       OBJECTS OF THE INVENTION  
       [0009]     Accordingly, several objects and advantages of the invention are as follows:  
         [0010]     An object of the present invention is to provide a less-lethal projectile which carries a liquid payload.  
         [0011]     It is also an object of the present invention to provide a less-lethal projectile which can be used to mark the target individual.  
         [0012]     A further object is to provide such a less-lethal projectile which carries a liquid payload and is stable in flight. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a side view, partially broken away, showing the projectile in flight;  
         [0014]      FIG. 2  is a side view, partially broken away, showing the projectile after impact;  
         [0015]      FIG. 3  is an exploded view of the embodiment of  FIGS. 1 and 2 ;  
         [0016]      FIG. 4  is an exploded view of another embodiment;  
         [0017]      FIG. 5  is an exploded view of yet another embodiment;  
         [0018]      FIG. 6  is a side view, partially broken away, of another embodiment, before impact;  
         [0019]      FIG. 7  is a side view, partially broken away, of the embodiment of  FIG. 6  after impact;  
         [0020]      FIG. 8  is a side view of another type of closure disk system; and  
         [0021]      FIG. 9  is a side view of another embodiment of the disk of  FIG. 8 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     Referring now to the drawings, there is shown in  FIGS. 1, 2 , and  3 , a projectile  10  having a body  12  with rotating band  14  integral to the body  12 . A supply of fluid  16  is contained within a cavity  18  inside of body  12 . A frangible closure disk  20  holds fluid  16  in cavity  18 . Frangible closure disk  20  has a circular groove  36 , which provides a weak point, allowing closure disk  20  to break loose more easily on impact.  
         [0023]     Frangible disk  20  has a small cylindrical projection  21  which projects into fluid cavity  18 . Projection  21  acts as an expansion volume, molded into disk  20 , where the fluid can expand, if the fluid is exposed to high storage temperatures. This expansion area is necessary, as fluid expansion, if not allowed for, would rupture disk  20  prior to launch or prior to impact.  
         [0024]     An inner, hard-nosed cap  22  is attached to body  12  by an adhesive at assembly. An outer soft-nosed cap  24  covers hard-nosed cap  22 . Soft-nosed cap  24  is bonded to hard-nosed cap  22  at manufacture as part of the molding process. There is an air gap or empty volume  26  between closure  20  and nose caps  22  and  24 . Slits  28 ,  30 ,  32  and  34  are present in the surface of both caps  22  and  24 . Slits  28 ,  30 ,  32  and  34  in hard and soft nose caps  22  and  24  are collinear, so that the slits coincide.  
         [0025]      FIG. 1  shows the complete projectile  10  in flight.  FIG. 2  shows projectile  10  after impact. Upon impact, the hard-nosed cap  22  is deformed and the force of the impact causes slits  28 ,  30 ,  32  and  34  to spread open, at which time the slits are permanently reformed to an open state. Soft-nosed cap  24  is bonded to hard-nosed cap  22  and the slits of soft-nosed cap  24  are spread open at impact, at the same time as the slits of hard-nosed cap  22 .  
         [0026]     On impact, closure disk  20  ruptures at weakened circular groove  36  by the inertia of fluid mass  16 , and disk  20  is pushed against the inside of hard nose cap  22 . Fluid  16  has escaped through open slits  28 ,  30 ,  32  and  34 , and has splashed the target radially from the point of impact.  
         [0027]     Referring now to  FIG. 4 , there is shown another embodiment of the invention which involves the use of only one cap rather than the combination hard inner cap and soft outer cap. There is shown the body  40  with integral rotating band  42  molded in. A cavity  44  is located inside of the body to contain a liquid. Body  40  has a shoulder area  46  at the outer diameter, on which is seated frangible closure disk  48 . Frangible disk  48  is held in place between shoulder  46  of body  40  and shoulder  56  of cap  54 . Frangible disk  48  has a circular groove  50 , which allows frangible disc  48  to break, from the force of the fluid contained in cavity  44  being thrust forward at the time of impact. This releases the fluid into cap  54 . Cap  54  is made from a flexible but relatively stiff rubber material.  
         [0028]     Cap  54  has a plurality of slits  60 ,  62 ,  64  and  66  which are deformed at impact and spread open, causing the fluid to escape through the open slits and splash the target radially from the point of impact, similar to the embodiment shown in  FIGS. 1-3 .  
         [0029]     Frangible disk  48  has a small cylindrical projection  68  which projects into fluid cavity  44 . Projection  68  acts as an expansion volume, molded into disk  48  where the fluid would expand if the fluid is exposed to high storage temperatures. This expansion area is necessary as fluid expansion, if not allowed for, would rupture disk  48  prior to launch or prior to impact.  
         [0030]     Referring now to  FIG. 5 , there is shown another embodiment of the invention which comprises a projectile having a body  70  with a rotating band  72  integral to the body  70 . The projectile has an open space or chamber  74  to hold a liquid, a frangible closure disk  76  having a cylindrical expansion area  78  and a circular groove  80 , which are all similar to the embodiment shown in  FIG. 4 . Body  70  has an annular shoulder  84  for placement of frangible disk  76 .  
         [0031]     In this embodiment cap  86  is also made of a flexible, but fairly stiff, rubber material which has a rounded front surface  88 . The rounded-front cap  86  may be more desirable in certain instances, relating to the effect of the impact on the target person. The rounded cap may do less damage to the target than the cap shown in the  FIG. 4 . Cap  86  has a series of slits as previously described,  90 ,  92 ,  94  and  96 . Cap  86  also has an annular shoulder  98  for the seating of frangible disc  76 , between shoulder  84  and shoulder  98 . On impact, frangible disc  76  breaks at circular groove  80  and is thrust forward into the front of cap  86 , releasing the liquid through slits  90 ,  92 ,  94 ,  96  which are spread open at the time of impact.  
         [0032]     While only one cap is shown, the cap may also be made with the double cap structure of  FIG. 1 , comprising an inner hard nose cap and an outer soft nose cap adhered together, both caps having a rounded front.  
         [0033]     Referring now to  FIG. 6  and  FIG. 7  there is shown another embodiment of the invention, which shows a projectile  100  having a body  102  with a rotating band  104 . Fluid  106  is contained in a chamber  108  within body  102 .  FIG. 6  describes the projectile prior to impact and  FIG. 7  after impact.  
         [0034]     In this embodiment, a central limiting column  110  is provided in body  102 . Cap  112  has a second limiting column  114 .  
         [0035]     A frangible disk  116 , having a circular groove  118 , rests against two shoulders  122  and  124 . Shoulder  122  is part of body  102  and shoulder  124  is located at the end of limiting column  110 . Cap  112  has a plurality of slits  126 ,  128 ,  130  and  132 .  
         [0036]     Frangible disk  116  holds liquid  106  within chamber  108  of body  102 . Disk  116  is held between shoulder  122  and shoulder  126  of cap  112 . Frangible disk  116  has a central hole to fit over the end of limiting column  110 .  
         [0037]     On impact, liquid  106  is thrust forward breaking frangible disc  116  at circular grooves  118  and  120 . On impact, frangible disk  116  breaks at both grooves  118  and  120  and is thrust forward into the inside of cap  112 . On impact limiting column in cap  114  strikes against the end of limiting column  110  in body  102 , which stops any further movement of the center of cap  112 . Slits  128 ,  130 ,  132  and  134  are forced open and fluid  106  escapes through the open slits and splashes the target radially from the point of impact.  
         [0038]     In the first embodiment shown, the inner cap is made of a plastic such as polyethylene. When polyethylene is used alone, it creates a sharp edge at the slits when they are forced open. To avoid potential injuries from the rotating projectile, a rubber nosecap is added to cover the sharp edges of the slits. It is necessary that the rubber nosecap not come in contact with the gun barrel as it is being launched. Any contact would change the launch dynamics, slowing down the projectile. Thus, the rubber cap is smaller in diameter than the body of the projectile, so that the rubber cap does not come in contact with the gun barrel as the projectile is being launched.  
         [0039]     Referring now to  FIG. 8 , there is shown another embodiment of the frangible disk. In this embodiment, frangible disk  140  is made of cardboard with a polymer coating layer  142 . Polymer layer  142  faces the liquid, so that the liquid does not penetrate disk  140 . Disk  140  has a circular notch or groove  144  allowing it to break easily on impact. Because cardboard disk  140  is not as strong as a plastic disk used in the earlier embodiments, it is necessary to use a washer  146 , having a large hole  148  through it, as support for disk  140 .  
         [0040]      FIG. 9  shows a washer  150  resting against shoulder  152  of cap  154 . Frangible cardboard disc  156  has a concave shape, facing washer  150 . A shoulder of the body of a projectile will press against disk  156  holding it firmly against shoulder  152 . The concave shape of disk  156  is to provide for expansion of the liquid in the projectile against disk  156 . In the event the liquid in the projectile is exposed to high storage temperatures, disk  156  will be pushed forward, towards washer  150 , so that disk  156  will not fracture prior to impact.  
         [0041]     Having thus described the invention,