Patent Abstract:
A device and method introduces the use of conventional ammunitions to the archery/bow hunting industry. The device achieves stealthy delivery of firearm munitions and increases the firepower of standard arrows resulting in deeper penetration into a target. The device consists generally of a cylindrical housing threaded internally on one end for attachment to a firing pin assembly. A firing pin is slideably attached to the firing pin assembly. A cartridge is loaded into the housing until the flange on the cartridge casing abuts an interior shoulder. In an alternate embodiment, the interior of the housing further includes an annular retaining tab. The retaining tab separates the cartridge from the firing pin to prevent inadvertent discharge. A cap or nosepiece may be included to further protect the device from accidental discharge of the cartridge and to provide aerodynamic advantages. The housing further includes a set of stabilizing vanes.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 13/764,302, filed Feb. 11, 2013, which claims priority to Provisional Application No. 61/649,816, filed May 21, 2012 and is a continuation-in-part of application Ser. No. 13/726,446, filed Dec. 24, 2012, which is a continuation-in-part of application Ser. No. 13/488,684, filed Jun. 5, 2012, now U.S. Pat. No. 8,568,257, which is a continuation-in-part of application Ser. No. 13/199,901, filed Sep. 13, 2011, now U.S. Pat. No. 8,444,512, which is a continuation-in-part of application Ser. No. 12/928,772, filed Dec. 16, 2010, now U.S. Pat. No. 8,439,777. Each patent application identified above is incorporated here by reference in its entirety to provide continuity of disclosure. 
    
    
     FIELD OF INVENTION 
     This disclosure relates to hunting equipment, and more particularly to an arrowhead capable of delivering firearm munitions stealthily and accurately to a target. 
     BACKGROUND OF THE INVENTION 
     In the sport of game hunting, the element of surprise is a valuable asset in the hunter&#39;s arsenal. If an intended game target is unaware that a hunter is near, the hunter&#39;s chances of landing the game are increased. Several methods of hiding a hunter are typically employed such as camouflage attire, hidden game blinds, and scent dispersing apparatus to not only hide the scent of the hunter, but to attract the game. Additionally, hunters may choose to use bow and arrows or crossbows as their weapon of choice to avoid the loud, animal deterring sound of gunfire. The drawback of using a bow and arrow though is that the hunter typically needs to be closer to the intended target and the power that an arrow delivers to a target tends to be less than a typical firearm. A clean, accurate, and powerful strike to the intended game target resulting in quick drop and expiration is most desirable. 
     The novel device and method discussed herein allows for the use of a bow and arrow or crossbow and delivers more power, energy, and accuracy to the archery industry than typical arrowheads. The device provides increased firepower, safety, accurate flight, clean deployment from the bow or crossbow, stealthy flight, and deeper penetration than standard arrowheads resulting in on the spot game expiration. Specifically, the device incorporates a standard bullet casing housed in a containment unit and paired with a firing pin that discharges the bullet only upon contact with the intended target. The device is especially designed to insure a consistent ignition upon contact by transferring a larger proportion of momentum and energy of impact to the ignition process. 
     U.S. Pat. No. 6,311,623 to Zaruba discloses an arrowhead having a powder-charged projectile activated after a delayed interval. The device includes a bullet-shaped arrowhead housing, with or without a protective tip, having a cartridge contained in a cavity within. A plunger extending from the housing has a protrusion for contact with the cartridge upon impact with a target. The plunger is threaded onto an arrow shaft. In use, the arrow shaft collides with the target. The momentum of the arrow causes the protrusion of the plunger to contact the cartridge which ignites a primer to fire the projectile. 
     U.S. Pat. No. 3,580,172 to Hendricks discloses an underwater projectile for firing a cartridge upon impact with a target. The projectile includes a tubular body having an open fore end portion defining a gun bore and an intermediate portion defining a chamber for receiving a cartridge. A firing pin is slidably disposed within the intermediate portion of the tubular body and engages the primer of the cartridge to detonate the cartridge and the slug. 
     U.S. Pat. No. 2,780,860 to Arpin discloses a power spear. The device comprises a barrel which is threaded onto a shaft. The barrel includes a cartridge chamber which has a shoulder for seating a rearward facing cartridge blank. The barrel further includes an open end which houses a projectile or spearhead. The projectile has a pointed striking head on one end and a projection extending from a flat end opposite the pointed head. In use, the device contacts a target which drives the projectile rearward. The projection strikes the primer of the cartridge as to detonate it. The cartridge case itself acts directly against the flat end of the projectile and expels the projectile from the barrel. 
     U.S. Pat. No. 2,620,190 to Bean discloses a cap for darts and arrows. The cap is frictionally engaged with the arrowhead and shaft of an arrow. The cap is tubular in shape and conceals the leading edge of a cartridge to prevent accidental discharge. Upon impact, the momentum of the arrow detonates the cartridge. 
     Therefore, there is a need in the art to combine the power of firearm munitions with the stealthy delivery of an arrow which provides increased firepower, safety, accurate flight, clean deployment from the bow or crossbow, stealthy flight, and deeper penetration than standard arrowheads resulting in an increased chance of on the spot game expiration. 
     SUMMARY OF INVENTION 
     The device disclosed combines advantages of conventional firearms ammunition with those of archery and bow hunting. The device delivers more power, energy, and accuracy to the archery industry than typical arrowheads. The device provides increased firepower, safety, accurate flight, clean deployment from the bow or crossbow, stealthy flight, and deeper penetration than standard arrowheads. 
     Accordingly, the device is comprised of a generally hollow cylindrical containment housing in which a single standard firearm round is seated. A firing pin is secured to one end of the containment housing. The round or cartridge is comprised of a brass casing and slug as is common in the art. The generally cylindrical firing pin is threaded on both a narrow end for engagement with an arrow shaft and a wider end for engagement with the containment housing. The firing pin comprises an axially aligned protrusion for use with centerfire cartridges or offset protrusions for use with rimfire cartridges. In an alternate embodiment, the firing pin can be spring loaded. 
     The containment housing is generally a tapered, hollow cylinder typically bored to accommodate .38 caliber, .357 caliber, or .22 caliber bullets. Other calibers can be accommodated. The containment housing is threaded internally on an end for attachment to the firing pin and further includes an interior shoulder separating two cavities. A cartridge is loaded into the containment housing until the flange on the casing abuts the shoulder. In an alternate embodiment, the interior of the containment housing further includes an annular retainer tab integrally formed in the interior of the housing containment. The retainer tab separates the cartridge from the firing pin to prevent inadvertent discharge. In an alternate embodiment, the exterior of the containment housing comprises a set of vanes. 
     In an alternate embodiment, the containment housing is threaded externally on an end opposite the firing pin for attachment of a safety cap. The safety cap is generally cylindrical in shape, includes an aerodynamically shaped nose, and further includes internal threads for attachment with the external threads of the containment housing. The safety cap protects the cartridge from accidental discharge and is typically not removed until the time of deployment of the weapon. An alternate embodiment includes a “ratcheting” feature that prevents the safety cap from removal after installation. An additional alternate embodiment discloses a safety cap frictionally engaged with the containment housing intended to remain engaged with the housing during use. 
     In use, a cartridge is loaded in the containment housing. In some embodiments the cap is attached to the tapered end of the containment housing. The firing pin is attached to the containment housing. The device is threaded onto an arrow shaft or bolt. The device, attached to an arrow shaft or bolt, is deployed at a target. Upon impact, the cartridge is driven back into the firing pin. The firing pin contacts the primer of the cartridge causing discharge. The slug is propelled into the target. 
     In some cases, the arrow shaft shatters which prevents sufficient energy transfer to the firing pin. In a preferred embodiment, a retaining ring is provided which transfers energy from the shattered shaft to the firing pin thereby discharging the cartridge. 
     The result of use of the device is generally deeper penetration and quiet use of ammunition. A less powerful and lighter bow may be used in conjunction with the device and still achieve a more powerful strike than a standard arrowhead. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein: 
         FIG. 1  is an exploded perspective view of an ammunition delivery system arrowhead and arrow of this disclosure. 
         FIG. 2A  is an exploded, partial cut-away view of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 2B  is an assembled, partial cut-away view of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 3A  is an exploded, partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 3B  is an assembled, partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 4A  is an exploded, partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 4B  is an assembled partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 5A  is an elevation view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 5B  is an exploded, partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 5C  is an assembled partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 6A  is an elevation view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 6B  is an exploded, partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 6C  is an assembled partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 7A  is an elevation view of an alternate embodiment of a firing pin of the ammunition delivery system arrowhead of this disclosure. 
         FIG. 7B  is an end view of an alternate embodiment of a firing pin of the ammunition delivery system arrowhead of this disclosure. 
         FIG. 8A  is an assembled side view of an ammunition delivery system arrowhead of this disclosure, prior to launch and during flight. 
         FIG. 8B  is an end view of a housing of the ammunition delivery system arrowhead of this disclosure. 
         FIG. 9A  is an exploded, partial cut-away view of an alternate embodiment of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 9B  is an end view of a head of a firing pin of the ammunition delivery system arrowhead of this disclosure. 
         FIG. 10A  is an assembled cut-away view of an ammunition delivery system arrowhead of this disclosure. 
         FIG. 10B  is an assembled cut-away view of an ammunition delivery system arrowhead. 
         FIG. 10C  is an assembled cut-away view of an ammunition delivery system arrowhead. 
         FIG. 11  is an assembled cut-away view of an alternate embodiment of an ammunition delivery system arrowhead. 
         FIG. 12  is a test comparison of the penetration depths of a preferred embodiment of an ammunition delivery system arrowhead of this disclosure versus an arrow having a standard arrowhead. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the descriptions that follow, like parts are marked throughout the specification and drawings with the same numerals, respectively. The drawing figures are not necessarily drawn to scale and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness. 
     Referring to  FIG. 1 , arrow  100  is comprised of shaft  104  attached to arrowhead  101 . Shaft  104  has an open forward end  110  that includes internal threads  112 . Nock  106  is formed in distant end  114  to accommodate a bow string. Forward end  110  of shaft  104  is open and arrowhead  101  is positioned therein. Fletchings  108  surround the circumference of shaft  104  equidistantly at distant end  114  adjacent nock  106 . As is common in the art, two, three, or four fletchings may be incorporated. 
       FIGS. 2A and 2B  show ammunition delivery system arrowhead  101 . Arrowhead  101  is comprised of firing pin  120  threadably engaged with containment housing  124 . Containment housing  124  is generally cylindrical and encases cartridge  122 . 
     Firing pin  120  is comprised of threaded section  130 , middle section  132 , and head section  134 . Threaded section  130  includes threads  146  sized to engage threads  112  of shaft  104 . Threaded section  130  is integrally formed with middle section  132 . Middle section  132  is cylindrically shaped and typically has a diameter generally equal to the diameter of shaft  104 . Head section  134  is integrally formed with middle section  132  and further includes threads  136 . Protrusion  138  extends from head section  134 . Protrusion  138  is generally concentrically aligned with the longitudinal axis of firing pin  120  to operate with a centerfire cartridge but could also be offset in order to operate with a rimfire cartridge. Firing pin  120  is preferably manufactured of aluminum, steel, or rigid molded plastic. 
     Cartridge  122  is of design and composition common in the art. Cartridge  122  is comprised of casing  142  having base  140 . Slug  144  is housed in and extends from casing  144 . Cartridge  122  is preferably sized as .38 caliber, .357 caliber, or .22 caliber. However, containment housing  124  can be sized to accommodate any commercially available cartridge caliber as larger and smaller munitions are envisioned by this disclosure. Cartridge  122  may be a centerfire cartridge or a rimfire cartridge. Rimfire cartridges are typically limited to low pressure calibers because they require a thin casing so that a firing pin can crush the base and ignite the primer. Rimfire cartridges are relatively light and inexpensive as compared to centerfire cartridges. 
     Containment housing  124  is generally a hollow cylinder having rearward opening  152  and forward opening  150 . The exterior of containment housing  124  has a leading end separated from a trailing end by collar ring  128 . The diameter of the leading end is generally less than the diameter of the trailing end thus collar ring  128  provides aerodynamic advantages to help stabilize the arrowhead during use. The interior of containment housing  124  includes a cylindrically shaped cavity  158  adjacent a second concentrically aligned and cylindrically shaped cavity  148 . Shoulder  156  separates cavity  148  from cavity  158 . Rearward opening  152  is sized to accommodate head section  134  of firing pin  120 . Rearward opening  152  leads to cavity  148 . Cavity  148  includes threads  154  which engage threads  136 . Forward opening  150  leads to cavity  158 . Cavity  158  and forward opening  150  have a diameter only slightly larger than the diameter of casing  142  which allows cartridge  122  to be press fit inside containment housing  124  and frictionally held in place. In an alternate embodiment, an adhesive or induction welding may be employed to further secure cartridge  122  inside containment housing  124 . 
     Containment housing  124  is preferably manufactured of molded plastic. In one embodiment, the plastic is an acrylic resin which is transparent to allow the cartridge to be seen through the housing in order to determine if the weapon is loaded. In another embodiment, the plastic is a low cost variety of polypropylene. 
       FIG. 2B  shows arrowhead  101  as assembled. Cartridge  122  rests in cavity  158  and base  140  abuts shoulder  156 . Slug  144  extends through forward opening  150 . Head section  134  of firing pin  120  is threadably engaged with containment housing  124 . Threads  154  and threads  136  prevent firing pin  120  from advancing too far into cavity  148 . As a result, gap  162  exists between protrusion  138  and base  140 . Threads  146  of threaded section  130  engage internal threads  112  to securely attach the arrowhead to shaft  104 . 
     In use, cartridge  122  is loaded, slug  144  first, into containment housing  124  through rearward opening  152 . Cartridge  122  is advanced through cavity  148  and through cavity  158  until base  140  abuts shoulder  156 . Firing pin  120  is attached to containment housing  124  such that threads  136  engage threads  154 . Firing pin  120  is tightened to containment housing  124  such that gap  162  exists between protrusion  138  and cartridge  122  to complete assembly of the ammunition delivery system arrowhead. Arrowhead  101  is attached to shaft  104  such that threads  146  engage internal threads  112  to complete assembly of arrow  100 . 
     Arrow  100  is typically delivered to an intended target through the use of a bow or cross bow. When arrowhead  101  strikes the intended target, cartridge  122  slides backwards through containment housing  124  and is forced into protrusion  138  thereby impacting the primer, discharging the cartridge, and expelling slug  144  from casing  142 . Slug  144  is propelled into the intended target. As shaft  104  and firing pin  120  are rarely damaged in use, both shaft  104  and firing pin  120  may be reused with a new cartridge and containment housing repeatedly after recovery. 
       FIG. 3A  shows an alternate embodiment of arrowhead  102 . Containment housing  124  further includes retaining tab  160 . Retaining tab  160  is an annular wedge shaped projection extending from the interior surface of containment housing  124  into cavity  148 . The size of retaining tab  160  is relative to the caliber of cartridge being employed. A larger caliber results in the need for a larger retaining tab. In a preferred embodiment, retaining tab  160  may also be a single projection or a collection of projections spaced in the same plane around the interior circumference. Formed between retaining tab  160  and shoulder  156  is slot  166 . Slot  166  is sized to fit base  140  of cartridge  122 . 
       FIG. 3B  shows arrowhead  102  as assembled. Cartridge  122  is housed in cavity  158 . Base  140  rests in slot  166  adjacent retaining tab  160  and shoulder  156 . Slug  144  extends through forward opening  150 . Firing pin  120  is threadably engaged with containment housing  124 . Threads  154  and threads  136  prevent over insertion of firing pin  120  into cavity  148  resulting in gap  162  between protrusion  138  and base  140 . Retaining tab  160  prevents cartridge  122  from sliding backwards and contacting firing pin  120  during flight and to reduce the possibility of accidental discharge should the arrowhead be dropped or knocked against a hard surface. Threads  146  of threaded section  130  engage internal threads  112  to securely attach the arrowhead to shaft  104 . 
     In use, cartridge  122  is loaded into containment housing  124  through rearward opening  152 . Cartridge  122  is advanced through cavity  148  and cavity  158  until base  140  passes over retaining tab  160  and abuts shoulder  156 . The wedge shape and relative size of retaining tab  160  allows base  140  to pass over retaining tab  160  until base  140  abuts shoulder  156  and rests in slot  166 . Firing pin  120  is attached to containment housing  124  such that threads  136  engage threads  154 . Firing pin  120  is tightened to containment housing  124 . Retaining tab  160  and gap  162  separate protrusion  138  from cartridge  122 . Arrowhead  102  is attached to shaft  104  such that threads  146  engage internal threads  112  to complete assembly of arrow  100 . Arrow  100  is delivered to an intended target. When arrowhead  102  strikes the intended target, cartridge  122  slides backward through containment housing  124  breaking retaining tab  160 . Cartridge  122  contacts protrusion  138  discharging cartridge  122 . Slug  144  is propelled from casing  142  and containment housing  124  into the intended target. Shaft  104  may be reused with a freshly assembled ammunition delivery system arrowhead once the used arrowhead is removed. 
       FIG. 4A  shows an alternate embodiment, arrowhead  103 . Spring  194  is positioned between firing pin  120  and cartridge  122 . Spring  194  may be attached to firing pin  120 . In the preferred embodiment, spring  194  is formed from steel and has a spring constant in the range of 20 to 100 N/m, other spring constants will suffice. Also, in a preferred embodiment, the spring takes the form of a frustoconical helical spring. In this embodiment, the spring, when compressed, is thin enough to allow contact of the primer with the protrusion. In general, protrusion  138  is capable of extending through the length of a fully compressed spring  194 . In an alternate embodiment, spring  194  is comprised of synthetic foam. 
     Containment housing  124  further includes threads  164  and window  126 . Housing  124  is engaged with cap  170 . Threads  164  surround the exterior of containment housing  124  adjacent to forward opening  150 . Cap  170  is generally cylindrical and includes an open end, a closed end, and cavity  188 . Cap  170  may also include vent  190 . Vent  190  is a hole or plurality of radial holes which pass through cap  170  and in to cavity  188 . Adjacent the open end are threads  168 . Threads  168  are on the interior of cap  170  and are sized to engage threads  164 . Cap  170  protects cartridge  122  from accidental discharge should an assembled arrowhead be dropped or knocked against a hard surface. Window  126  is a hole passing through the exterior of containment housing  124  and opening into cavity  158 . Window  126  allows a user to visually identify if a cartridge has been loaded in containment housing  124  without removing cap  170 . In an alternate embodiment, cap  170  is made of a flexible material such as neoprene and does not include internal threads. In a preferred embodiment, cap  170  is press fit into place over forward opening  150 . 
       FIG. 4B  shows arrowhead  103  assembled. Cartridge  122  rests in cavity  158  and base  140  abuts shoulder  156 . Slug  144  extends through forward opening  150 . Head section  134  of firing pin  120  is threadably engaged with containment housing  124 . Threads  154  and threads  136  prevent firing pin  120  from over insertion into cavity  148 . As a result, gap  162  exists between protrusion  138  and base  140 . Spring  194  biases cartridge  122  away from firing pin  120  to safeguard cartridge  122  from accidently contacting protrusion  138  and discharging the cartridge. Threads  168  of cap  170  engage threads  164  to securely attach cap  170  to containment housing  124 . Gap  192  separates cartridge  122  from the interior surface of cap  170 . Threads  146  of threaded section  130  engage internal threads  112  to securely attach the arrowhead to shaft  104 . In an alternate embodiment, retaining tab  160  may be used in conjunction with a containment housing incorporating cap  170 . 
     In use, cartridge  122  is loaded into containment housing  124  through rearward opening  152 . Cartridge  122  is advanced through cavity  148  and through cavity  158  until base  140  abuts shoulder  156 . Firing pin  120  is attached to containment housing  124  such that threads  136  engage threads  154  and spring  194  abuts base  140 . Firing pin  120  is tightened to containment housing  124  against the bias of spring  194  until protrusion  138  is separated from cartridge  122  by gap  162 . Cap  170  is attached to containment housing  124  such that threads  168  engage threads  164 . Arrowhead  103  is attached to shaft  104  such that threads  146  engage internal threads  112  to complete assembly of arrow  100 . If needed, a user may observe a cartridge through window  126  without removing the cap. In preparation for deployment, cap  170  is removed from containment housing  124 . Arrow  100  is deployed. When arrowhead  103  strikes the intended target, cartridge  122  slides backward through containment housing  124  against the bias of spring  194  into protrusion  138  thereby discharging cartridge  122 . Slug  144  is propelled into the intended target. Shaft  104  may be reused with another ammunition delivery system arrowhead once the used arrowhead is removed. 
     In an alternate embodiment, cap  170  is not removed and thus remains engaged with housing  124  during use. Vent  190  allows the escape of ignition gases after the discharging of cartridge  122 . 
       FIGS. 5A and 5B  show an alternate embodiment, arrowhead  105 . Arrowhead  105  is comprised of firing pin  520  threadably engaged with housing  524 . Cone  526  is pressfit in to housing  524 . Cartridge  122  is seated within housing  524 . 
     Firing pin  520  is generally cylindrically shaped and comprised of threaded section  530 , middle section  532 , and head section  534 . All three sections of firing pin  520  are integrally formed and axially aligned. Threaded section  530  includes threads sized to engage threads  112  of shaft  104 . Head section  534  includes threads  536 . Head section further includes collar  537 . Collar  537  has a diameter slightly larger than the diameter of the remainder of head section  534 . Protrusion  538  extends from head section  534  and is generally concentrically aligned with the longitudinal axis of firing pin  520 . Firing pin  520  is preferably manufactured of aluminum, steel, or rigid molded plastic. 
     Housing  524  is generally a hollow cylinder having rearward opening  552  at end  553  and forward opening  550  at end  551 . End  553  has a slightly larger diameter than end end  551  thus the exterior of containment housing  524  tapers through its length from end  553  to end  551 . The interior of housing  524  includes a cylindrically shaped cavity  558  adjacent a second concentrically aligned and cylindrically shaped cavity  548 . Shoulder  556  separates cavity  548  from cavity  558 . Rearward opening  552  is sized to accommodate head section  534  of firing pin  520 . Rearward opening  552  opens to cavity  548 . Cavity  548  includes threads  554  which engage threads  536 . Forward opening  550  opens to cavity  558 . Housing  524  is preferably manufactured of molded plastic, transparent acrylic resin, or polypropylene. Cone  526  is made of lubricated nylon material and includes a pointed nose  570  and a generally dome shaped cavity  588 . 
     As shown in  FIG. 5C , as assembled, cartridge  122  rests in cavity  558  and base  140  abuts shoulder  556 . Head section of firing pin  520  is threadably engaged with housing  524 . Firing pin  520  is advanced into cavity  548  until collar  537  abuts end  553 . As a result, gap  562  exists between protrusion  538  and base  140  of cartridge  122 . Cone  526  is frictionally engaged with housing  524  in forward opening  550  but adhesive may also be used. Cavity  588  surrounds slug  144 . Threaded section  530  engages threads  112  to attach arrowhead  105  to shaft  104 . In an alternate embodiment, spring  194  may be positioned between firing pin  520  and cartridge  122 . Spring  194  may be attached to firing pin  520 . 
     In use, cartridge  122  is inserted into housing  524  through rearward opening  552 . Cartridge  122  is advanced through cavity  548  and through cavity  558  until base  140  abuts shoulder  556 . Firing pin  520  is threadably attached to housing  524 . Firing pin  520  is tightened to housing  524  until collar  537  abuts end  553 . Gap  162  is formed between protrusion  138  and cartridge  122 . Cone  526  is press fit in to forward opening  550 . Arrowhead  105  is threadably attached to shaft  104 . 
     Cone  526  is preferably left in place during use. Pointed nose  570  provides aerodynamic advantages and imparts deeper penetration into an intended target over blunt shaped cartridges. As arrowhead  105  strikes the intended target, cone  526  shatters and cartridge  122  slides backward through housing  524  into protrusion  538 . Cartridge  122  is discharged and slug  144  is propelled into the intended target. Shaft  104  and firing pin  520  may be reused with a new housing, cartridge, and nose. 
       FIGS. 6A and 6B  show an alternate embodiment, arrowhead  107 . Arrowhead  107  is comprised of firing pin  520  threadably engaged with housing  624 . Cap  626  is pressfit onto housing  624 . Cartridge  122  is seated within housing  624 . 
     Housing  624  is generally a hollow cylinder having rearward opening  652  at end  653  and forward opening  650  on the opposite end. Housing  624  includes a cylindrically shaped cavity  658  adjacent a second concentrically aligned and cylindrically shaped cavity  648 . Shoulder  656  is adjacent both and separates cavity  648  from cavity  658 . Rearward opening  652  opens to cavity  648 . Cavity  648  includes threads  654  which engage threads  536 . Forward opening  650  opens to cavity  658 . The exterior of housing  624  includes shoulder  668 . Housing  624  includes vanes  664 . Vanes  664  are generally triangular shaped and are integrally formed with housing  624 . As shown, vanes  664  comprise four equidistantly spaced groups of three longitudinally aligned vanes extending from housing  624  at end  653 . It is envisioned that more or fewer vanes in a group and more or fewer groupings of vanes is possible. The total number of vanes and the configuration of the vanes around housing  624  can be adjusted according to intended use or cartridge size. Vanes  664  provide aerodynamic advantages which help stabilize the arrowhead during use. Cap  626  is generally a hollow cylinder and includes a forward end  670  and an open end  672 . Forward end  670  includes hole  671 . Cap  626  includes a plurality of equidistantly spaced slits  674 . 
     As shown in  FIG. 6C , when assembled, cartridge  122  rests in cavity  658  and base  140  abuts shoulder  656 . Head section of firing pin  520  is threadably engaged with housing  624 . Firing pin  520  is advanced into cavity  648  until collar  537  abuts end  653 . As a result, gap  662  exists between protrusion  538  and base  140 . Cap  626  is frictionally engaged with housing  624  and advanced over forward opening  650  until cap  626  abuts shoulder  668 . Threaded section  530  engages threads  112  to attach arrowhead  107  to shaft  104 . In an alternate embodiment, spring  194  may be positioned between firing pin  520  and cartridge  122  and spring  194  may be attached to firing pin  520  with adhesive or other common in the art methods. 
     In use, cartridge  122  is inserted into housing  624  through rearward opening  652 . Cartridge  122  is advanced through cavity  648  and through cavity  658  until base  140  abuts shoulder  656 . Firing pin  520  is threadably attached to housing  624  at end  653 . Firing pin  520  is tightened to housing  624  until collar  537  abuts end  553  and thus gap  662  is maintained between protrusion  138  and cartridge  122 . Cap  626  is press fit over forward opening  550 . Arrowhead  105  is threadably attached to shaft  104 . 
     Cap  626  remains engaged with housing  624  during use. As arrowhead  107  strikes the intended target, cap  626  shatters and cartridge  122  slides backward through housing  624  into protrusion  538 . Cartridge  122  is discharged and slug  144  is propelled into the intended target. Slits  674  and hole  671  allow the escape of ignition gases after the discharging of cartridge  122 . Slits  674  also function as a flash suppressor diverting the discharge flare to radial angles away from the axis of travel. Shaft  104  and firing pin  520  may be reused with a new housing, cartridge, and nose. 
       FIGS. 7A and 7B  show an alternate embodiment of a firing pin. Firing pin  720  is comprised of threaded section  730 , middle section  732 , and head section  734 . Threaded section  730  includes threads  746  sized to engage threads  112  of shaft  104 . Threaded section  730  is integrally formed with middle section  732 . Middle section  732  is cylindrically shaped and typically has a diameter generally equal to the diameter of shaft  104 . Head section  734  is integrally formed with middle section  732  and further includes threads  736 . Protrusions  738  and  739  extend from head section  734 . Protrusions  738  and  739  are generally located near the perimeter of head section  734 . Protrusions  738  and  739  are offset from the longitudinal central axis of firing pin  720  in order to operate with a rimfire cartridge. The offset protrusions are not limited to two. Firing pin  720  is preferably manufactured of aluminum, steel, or rigid molded plastic. Firing pin  720  can be used with any of the previously described arrowhead configurations. 
       FIGS. 8A and 8B  show an alternate embodiment of an arrowhead  109 . 
     Referring to  FIG. 8A , arrowhead  109  comprises housing  824  and cap  826 . Firing pin  820  is slideably positioned within the housing. Firing pin  820  is also threadably secured to shaft  104 . Shaft impact ring  830  is slideably positioned on the firing pin. Further, the firing pin is secured in the housing by retaining collar  837 . 
     Referring to  FIG. 8B , in the preferred embodiment, housing  824  includes vanes  864 . Vanes  864  are generally triangular shaped and are integrally formed with housing  824 . As shown, vanes  864  comprise four equidistantly spaced groups of three longitudinally aligned vanes extending from housing  824 . In alternate embodiments, different numbers and positions of vanes are possible. Vanes  864  provide aerodynamic stabilization to the arrowhead during flight. 
     Referring to  FIG. 9A , firing pin  820  is slideably engaged with housing  824 . Firing pin  820  is centered on longitudinal axis  810 . Firing pin  820  includes cylindrical shaft  844  attached to head  840  having a shoulder  842  and a protrusion  841 . Firing pin  820  further comprises cylindrical shaft  832  adjacent cylindrical shaft  844 . Shoulder  833  separates cylindrical shaft  832  from cylindrical shaft  844  where cylindrical shaft  832  has a smaller diameter than cylindrical shaft  844 . Firing pin further comprises threaded shaft  834  adjacent cylindrical shaft  832 . Threaded shaft  834  is attached to shaft  104 . Retaining collar  837  includes hole  839 , rear shoulder  838 , front shoulder  831  and shoulder  835 . Firing pin  820  is inserted through hole  839  of the retaining collar. Shaft impact ring  830  is slideably positioned on cylindrical shaft  832  between shoulder  833  and threaded shaft  834 . 
       FIG. 9B  shows protrusion  841  is positioned off center of the longitudinal axis and near the perimeter of head  840 . 
     Referring to  FIGS. 10A and 10B , cap  826  fits onto housing  824  and is held in place by friction. Cap  826  is generally a hollow cylinder and includes a forward end  870  and an open end  872 . Forward end  870  includes hole  871 . Cap  926  includes a plurality of equidistantly spaced slits  874  which expand to hold the cap in place. When in place, the cap abuts shoulder  868 . 
     Housing  824  is generally a hollow cylinder, centered on longitudinal axis  810 , having rearward opening  852  and forward opening  850 . Housing  824  includes chamber  858  and chamber  848 . Cartridge  122  is seated within housing  824 . Chamber  858  is adjacent to and aligned with chamber  848 . Both chambers are generally cylindrical. Shoulder  856  separates chamber  848  from chamber  858 . Chamber  848  includes a rearward opening  852  and a forward opening  850 . Chamber  848  also includes threads  854  which engage threads  836 . 
     Cartridge  122  is positioned in chamber  858  where base  140  abuts shoulder  856 . The cartridge remains frictionally fixed in place. Cap  826  is fixed to forward opening  850 . Retaining collar  837  is threaded into housing  824  at rearward opening  852 . 
     Shaft impact ring  830  is slideably attached to filing pin  820 . Gap  860  exists between head  840  and cartridge  122 . Gap  862  exists between shaft impact ring  830  and shoulder  833 . Firing pin  820  is movable within retaining collar  837  between a first position where shoulder  842  abuts shoulder  835  and a second position where protrusion  841  impacts cartridge  122 . 
     Referring to  FIG. 10B , on impact with a target, arrow shaft  104  and firing pin  820  slide forward to an impact position where gap  860  is closed. The abrupt forward motion of firing pin  820  causes gap  861  to open and protrusion  838  to be driven into contact with base  140 . The primer of bullet  122  is ignited. 
     Referring to  FIG. 10C , in some cases, arrow shaft  104  fractures on impact as shown. When this occurs, the shaft splinters and fails to deliver sufficient force to the firing pin to discharge the cartridge. However, the fractured arrow shaft does impact shaft impact ring  830 . When it does so, shaft impact ring  830  is driven forward to shoulder  833  whereupon it stops and imparts additional energy to the firing pin sufficient to discharge the cartridge. 
     Cap  826  may be engaged with housing  924  during use or may be removed before use. If left in place, upon discharge of the cartridge, slits  874  and hole  871  allow the escape of ignition gases and function as a muzzle flash suppressor. 
     Referring to  FIG. 11 , in an alternate embodiment of arrowhead  109 , a spring  845  may be positioned in chamber  848  between head  840  of firing pin  820  and base  140  of cartridge  122 . Spring  845  maintains gap  860  prior to impact. Upon impact, the spring collapses and allows the firing pin to contact and discharge the cartridge. Spring  845  may be attached to firing pin  820  with adhesive or other common means known in the art. 
     In the preferred embodiment, spring  845  is formed from steel and has a spring constant in the range of 20 to 100 N/m and takes the form of a frustoconical helical spring. Other spring constants and forms will suffice. The spring, when compressed, is thin enough to allow contact of the protrusion with the base. 
       FIG. 12  shows the test results of an ammunition delivery system arrowhead of the present disclosure discharged into ballistics test medium  172 . Ballistics test medium  172  is a twenty inch block of PERMA-GEL™ synthetic “soft tissue” medium. PERMA-GEL™ is used for the testing and comparison of different types of projectiles and loads and can be found at www.perma-gel.com. The bow used in the test was a 62 pound pressure bow at a distance of twenty yards. A conventional arrowhead, fired from the same bow, entered ballistics test medium  172  at point  174  and stopped at point  178 . The conventional arrowhead traveled approximately 8.3 inches through ballistics test medium  172 . An ammunition delivery system arrowhead as disclosed herein entered ballistics test medium at point  180 . At point  182 , approximately 4.2 inches into ballistics test medium  172 , the cartridge housed in the ammunition delivery system arrowhead was discharged. The discharged slug continued to point  186  penetrating an additional approximate twelve inches for a total penetration of approximately 16.3 inches. 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Technology Classification (CPC): 5