Patent Publication Number: US-9404722-B2

Title: Expandable broadhead with chisel tip

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation, and claims the benefit under 35 U.S.C. §120, of U.S. patent application Ser. No. 13/792,989, filed Mar. 11, 2013, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/740,008, filed Dec. 20, 2012, each of which is herein incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD OF INVENTION 
     The present invention generally relates to arrowheads for attachment to arrow shafts and, more particularly, to expandable broadhead arrowheads with chisel tips. 
     BACKGROUND OF THE INVENTION 
     In an effort to develop ever-more effective equipment for hunting and other sports, the archery industry has developed a wide range of arrowhead styles that are intended and suited for specific uses. One such style of arrowhead is the broadhead, a bladed arrowhead featuring multiple sharp cutting blades that are designed to greatly increase the effective cutting area of the arrowhead. This increased cutting area results in larger, more effective entrance and exit wounds in game hit by the arrowhead, leading to quick and humane kills and better blood trails. 
     While broadheads provide an improved cutting capability in comparison with non-bladed arrowheads (known as field points or nib points), many broadhead designs suffer from inferior aerodynamic properties when compared to their non-bladed counterparts. Broadhead blades deployed during flight of an arrow can result in undesirable effects, causing that arrow to veer off course from the flight path coinciding with the longitudinal axis of the arrow shaft. 
     Previous broadhead designs have attempted to improve the aerodynamics of the bladed arrowheads by hiding a substantial portion of each of the cutting blades within the ferrule during flight of the arrow, in a design known as an “expandable broadhead.” Upon impacting a target, the blades are deployed, opening up and exposing the sharp cutting surfaces of the blades. Examples of such previous expandable broadhead designs are described by U.S. Pat. No. 8,197,367, hereby incorporated by reference in its entirety, and are illustrated by the examples depicted in  FIG. 1A ,  FIG. 1B ,  FIG. 1C , and  FIG. 2 .  FIG. 1A , for example, depicts an existing expandable broadhead design  100  with two cutting blades  104   a  and  104   b . These cutting blades are rear deploying blades held in place with a shock-absorbing retaining device  105  consisting of an O-ring and/or collar that is designed to break on impact. The rear deploying design of the blades  104   a - b  enhances the kinetic energy of the expandable broadhead  100  on impact, ensures that the blades  104   a - b  deploy reliably, and increases the probability of substantial penetration into the target. With regard to various exemplary embodiments of such collars, U.S. provisional patent application Ser. No. 61/584,430 (filed Jan. 9, 2012, entitled Broadhead Collars) and U.S. patent application Ser. No. 13/736,680 (filed Jan. 8, 2013, entitled Broadhead Collars), are both incorporated herein by reference in their entirety. 
     The design  100  illustrated by  FIG. 1A  also features a two-sided “cut on contact” tip  102 , a sharpened double-edged piece of steel inserted into the nose of ferrule body  103 . The cut on contact tip  102  is designed to slice neatly through the hide of a target game animal and requires a low amount of energy for penetration. 
     Previous designs for expandable broadheads have incorporated cut on contact tips similar to cut on contact tip  102  of broadhead  100 .  FIG. 1B  depicts an example of an existing expandable broadhead design  106  that includes a ferrule body  107 , a cut on contact tip  108 , two rear deploying blades  110   a  and  110   b , and collar  112  as disclosed in U.S. provisional patent application Ser. No. 61/584,430 and U.S. patent application Ser. No. 13/736,680. 
       FIG. 1C  depicts an exploded view of an example of another existing expandable broadhead design  115 . This design  115  features a cut on contact tip  117 , two rear deploying blades  121   a  and  121   b , and a collar  123 . The cut on contact tip  117  is inserted into the ferrule body  120  and secured with a threaded fastener  116 . The rear deploying blades  121   a - b  are hidden within one or more blade recesses  119  in the ferrule body  120 , and secured to the ferrule body  120  by a threaded fastener  122 .  FIG. 2  depicts an example of yet another existing expandable broadhead design  200 , which includes a cut on contact tip  203  and three rear deploying cutting blades  205   a ,  205   b , and  205   c.    
     Exemplary views of existing cut on contact tips are illustrated by  FIGS. 3A-3C  and  FIGS. 4A-4C .  FIG. 3A  depicts a side view of cut on contact tip  300 ,  FIG. 3B  depicts a front view of cut on contact tip  300 , and  FIG. 3C  depicts a top view of cut on contact tip  300 . Similarly,  FIG. 4A  depicts a side view of cut on contact tip  400 ,  FIG. 4B  depicts a front view of cut on contact tip  400 , and  FIG. 4C  depicts a top view of cut on contact tip  400 . 
     While the cut on contact tips utilized by previous expandable broadhead designs can easily penetrate the hide of a targeted game animal with a low expenditure of kinetic energy, a need remains for an expandable broadhead design that features a chisel tip. Durability is one advantage provided by a chisel-tipped expandable broadhead, as the leading edge of the broadhead is the location most likely to sustain impact damage. The dense, sculpted chisel tip reduces the broadhead&#39;s susceptibility to such impact damage, especially when striking hard structures such as bone. 
     In addition to the chisel tip&#39;s resistance to impact damage, its comparatively large, dense structure increases the amount of mass in the nose of the expandable broadhead. This increase in density moves the center of mass of the projectile upon which the broadhead is mounted further forward, improving the flight characteristics of that projectile. The aerodynamics of the projectile upon which a chisel tip broadhead is mounted can be further improved by incorporating a spiraling, helical design for the chisel tip. This helical design directs air flow around the ferrule body of the broadhead, leading to increased rotation of the broadhead projectile and reducing the effects of side winds in flight. The effects of the directed air flow created by the chisel tip stabilize the flight path of the projectile to improve its flight characteristics and lead to enhanced accuracy and precision of arrow shots. 
     Furthermore, a chisel tip mounted on an expandable broadhead can result in an increase in the effectiveness of the deployment of the rear deployed cutting blades. The deployment of the cutting blades works best when the leading blunt edges of the retracted blades strike the hide of the targeted game animal on impact. By offsetting the alignment of the chisel tip&#39;s cutting edges with the alignment of the rear deployed cutting blades, the chisel tip ensures that the blunt edges of the retracted blades strike the animal&#39;s hide, causing the retracted blades to effectively deploy and expose their sharp cutting edges. 
     As discussed above, there is a need for an expandable broadhead design featuring a chisel tip that provides increased resistance to damage, results in improved flight performance, and aids in the effectiveness of deploying the expandable broadhead&#39;s cutting blades. Embodiments of the present invention, as described below, solve the need in the art for such a device. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention are directed to expandable broadheads for attachment to arrow shafts. In one embodiment, the expandable broadhead includes a ferrule body that has a nose section and at least one blade recess, a chisel tip inserted into the nose section of the ferrule body, and a plurality of blades residing at least in part in the at least one blade recess. The plurality of blades can be configured in a retracted configuration or a deployed configuration, and a shock-absorbing retainer can be provided to releasably engage with the plurality of blades, to retain the blades in the retracted configuration until impact. 
     In certain embodiments of the invention, the ferrule body is composed of a material selected from the group consisting of aluminum, titanium, magnesium, and carbon-fiber reinforced polymer. 
     In certain embodiments of the invention, the chisel tip is made from a material selected from the group consisting of stainless steels, tool steels, carbides, titanium alloys, tungsten alloys, and tungsten carbides. In further embodiments of the invention, the chisel tip is coated with a material selected from the group consisting of nickel, zinc, cadmium, and black oxide. 
     In certain embodiments of the invention, the shock-absorbing retainer includes one or more devices selected from the group consisting of an O-ring and a collar. 
     In certain embodiments of the invention, each of the plurality of blades includes a cutting edge, and the cutting edge is exposed in the deployed configuration. In further embodiments of the invention, each of the plurality of blades includes a blunt edge, and the blunt edge is exposed in the retracted configuration. 
     In certain embodiments of the invention, the chisel tip is multi-faceted. In further embodiments of the invention, the number of facets of the chisel tip is a multiple of the number of the plurality of blades. In still further embodiments of the invention, the chisel tip is a three-facet chisel tip or a four-facet chisel tip, and the facets of the chisel tip are concave. In other further embodiments of the invention, the number of facets of the chisel tip is different than the number of blades. 
     In certain embodiments of the invention, the expandable broadhead further includes cutting edges between the facets of the chisel tip. In further embodiments of the invention, the cutting edges are helical blades. In further embodiments of the invention, the cutting edges of the chisel tip bisect the separation angles of the plurality of blades. 
     In certain embodiments of the invention, the expandable broadhead has a cutting diameter of about 1 inch to about 2.5 inches in diameter 
     In certain embodiments of the invention, the expandable broadhead has a weight of about 75 grains to about 150 grains. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side view of an existing expandable broadhead design with two side cutting blades, a collar, and a cut on contact tip. 
         FIG. 1B  depicts a side view of an existing expandable broadhead design with two side cutting blades, a collar, and a cut on contact tip. 
         FIG. 1C  depicts an exploded view of an existing expandable broadhead design with two side cutting blades, a collar, and a cut on contact tip. 
         FIG. 2  depicts a perspective view of an existing expandable broadhead design with three side cutting blades, a collar, and a cut on contact tip. 
         FIG. 3A  depicts a side view of an existing cut on contact tip. 
         FIG. 3B  depicts a front view of an existing cut on contact tip. 
         FIG. 3C  depicts a top view of an existing cut on contact tip. 
         FIG. 4A  depicts a side view of an existing cut on contact tip. 
         FIG. 4B  depicts a front view of an existing cut on contact tip. 
         FIG. 4C  depicts a top view of an existing cut on contact tip. 
         FIG. 5A  depicts an exemplary side view of an expandable broadhead with a chisel tip, two side cutting blades, and a collar. 
         FIG. 5B  depicts an exemplary exploded view of  FIG. 5A . 
         FIG. 5C  depicts an exemplary side view of an expandable broadhead with a chisel tip, two side cutting blades, and a collar. 
         FIG. 6A  depicts an exemplary side view of an expandable broadhead with a chisel tip, three side cutting blades, and a collar. 
         FIG. 6B  depicts an alternate exemplary side view of the expandable broadhead shown in  FIG. 6A . 
         FIG. 7A  depicts an exemplary side view of a three-facet chisel tip. 
         FIG. 7B  depicts  FIG. 7A  when it is rotated ninety (90) degrees clockwise. 
         FIG. 7C  depicts an exemplary top view of  FIG. 7A . 
         FIG. 7D  depicts an exemplary side view of a four-facet chisel tip. 
         FIG. 7E  depicts  FIG. 7D  when it is rotated ninety (90) degrees clockwise. 
         FIG. 7F  depicts an exemplary top view of  FIG. 7D . 
         FIG. 8A  depicts an exemplary side view of a three-facet chisel tip. 
         FIG. 8B  depicts an exemplary cross-section view of a three-facet chisel tip, along line  8 B- 8 B of  FIG. 8A . 
         FIG. 8C  depicts an exemplary cross-section view of a three-facet chisel tip, along line  8 C- 8 C of  FIG. 8A . 
         FIG. 8D  depicts an exemplary cross-section view of a three-facet chisel tip, along line  8 D- 8 D of  FIG. 8A . 
         FIG. 8E  depicts an exemplary end view of  FIG. 8A . 
         FIG. 9A  depicts an exemplary side view of a four-facet chisel tip. 
         FIG. 9B  depicts an exemplary cross-section view of a four-facet chisel tip, along line  9 B- 9 B of  FIG. 9A . 
         FIG. 9C  depicts an exemplary cross-section view of a four-facet chisel tip, along line  9 C- 9 C of  FIG. 9A . 
         FIG. 9D  depicts an exemplary cross-section view of a four-facet chisel tip, along line  9 D- 9 D of  FIG. 9A . 
         FIG. 9E  depicts an exemplary end view of  FIG. 9A . 
         FIG. 10A  depicts an exemplary side view of an expandable broadhead design with a four-facet chisel tip and two side cutting blades. 
         FIG. 10B  depicts an exemplary end view of the expandable broadhead of  FIG. 10A . 
         FIG. 10C  depicts an exemplary side view of an expandable broadhead design with a three-facet chisel tip and three side cutting blades. 
         FIG. 10D  depicts an exemplary end view of the expandable broadhead of  FIG. 10C . 
         FIG. 10E  depicts an exemplary side view of an expandable broadhead design with a three-facet chisel tip and two side cutting blades. 
         FIG. 10F  depicts an exemplary end view of the expandable broadhead of  FIG. 10E . 
         FIG. 10G  depicts an exemplary side view of an expandable broadhead design with a four-facet chisel tip and three side cutting blades. 
         FIG. 10H  depicts an exemplary end view of the expandable broadhead of  FIG. 10G . 
         FIG. 11A  depicts an exemplary side view of an expandable broadhead design with two side blades, a collar, and a four-facet chisel tip. 
         FIG. 11B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 11A . 
         FIG. 11C  depicts an exemplary side view of a four-facet chisel tip. 
         FIG. 11D  depicts an exemplary cross-section view of a four-facet chisel tip, along line  11 D- 11 D of  FIG. 11C . 
         FIG. 11E  depicts an exemplary cross-section view of a four-facet chisel tip, along line  11 E- 11 E of  FIG. 11C . 
         FIG. 11F  depicts an exemplary cross-section view of a four-facet chisel tip, along line  11 F- 11 F of  FIG. 11C . 
         FIG. 11G  depicts an exemplary end view of the four-facet chisel tip of  FIG. 11C . 
         FIG. 12A  depicts an exemplary side view of an expandable broadhead design with two side blades, a collar, and a three-facet chisel tip. 
         FIG. 12B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 12A . 
         FIG. 12C  depicts an exemplary side view of a three-facet chisel tip. 
         FIG. 12D  depicts an exemplary cross-section view of a three-facet chisel tip, along line  12 D- 12 D of  FIG. 12C . 
         FIG. 12E  depicts an exemplary cross-section view of a three-facet chisel tip, along line  12 E- 12 E of  FIG. 12C . 
         FIG. 12F  depicts an exemplary cross-section view of a three-facet chisel tip, along line  12 F- 12 F of  FIG. 12C . 
         FIG. 12G  depicts an exemplary end view of the three-facet chisel tip of  FIG. 12C . 
         FIG. 13A  depicts an exemplary side view of an expandable broadhead design with two side blades, a collar, and a four-facet chisel tip. 
         FIG. 13B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 13A . 
         FIG. 14A  depicts an exemplary side view of an expandable broadhead design with two side blades, a collar, and a three-facet chisel tip. 
         FIG. 14B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 14A . 
         FIG. 15A  depicts an exemplary side view of an expandable broadhead design with three side blades, a collar, and a three-facet chisel tip. 
         FIG. 15B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 15A . 
         FIG. 16A  depicts an exemplary side view of an expandable broadhead design with three side blades, a collar, and a four-facet chisel tip. 
         FIG. 16B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 16A . 
         FIG. 17A  depicts an exemplary side view of an expandable broadhead design with three side blades, a collar, and a three-facet chisel tip. 
         FIG. 17B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 17A . 
         FIG. 18A  depicts an exemplary side view of an expandable broadhead design with three side blades, a collar, and a four-facet chisel tip. 
         FIG. 18B  depicts an exemplary perspective view of the expandable broadhead of  FIG. 18A . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     Embodiments of the present invention pertain to and provide designs for expandable broadheads with chisel tips for attachment to arrow shafts.  FIGS. 5A and 5B  provide exemplary views of a preferred embodiment of the present invention. In this preferred embodiment of the present invention, the expandable broadhead design  500  includes a ferrule body  516 . The ferrule body  516  includes at least one blade recess (such as shown in  FIG. 11B ), and the broadhead  500  further includes a chisel tip  502  inserted into the nose section  507  of the ferrule body  516 , a plurality of blades  504   a  and  504   b  residing at least in part in the at least one blade recess, and a shock-absorbing retainer  514 . 
     In a preferred embodiment of the present invention depicted by  FIGS. 5A-5B , the ferrule body  516  of the expandable broadhead  500  includes at least one blade recess (such as shown in  FIG. 11B ) to receive, at least in part, a plurality of blades  504   a  and  504   b . In certain embodiments, the one or more recesses for receiving the plurality of blades  504   a  and  504   b  consist of one or more slots (such as shown in  FIG. 11B ). In a preferred embodiment of the present invention, the ferrule body  516  also includes a nose section  507  and a rear section  509 . 
     In certain preferred embodiments of the present invention, the ferrule body  516  of the broadhead design  500  is a unitary molded or machined structure that includes various slots (such as shown in  FIG. 15B ), facets  508 , threads  518 , and the like. In other embodiments, the ferrule body  516  may include a plurality of components that are assembled. 
     In a preferred embodiment of the present invention, the rear section  509  of the ferrule body  516  includes threads  518  that couple with a conventional arrow shaft (not shown) or other projectile, such as a crossbow bolt. In certain embodiments, the nose section  507  of the ferrule body  516  may take a variety of forms, including but not limited to a conical, faceted, or a straight tapered structure. In a preferred embodiment, the nose section  507  of the ferrule body  516  includes one or more facets or flat regions  508 . The facets  508  increase the aerodynamic stability of the expandable broadhead  500  during flight, and in certain embodiments, the number of facets  508  may vary in accordance with various broadhead design factors. 
     In certain embodiments of the present invention, the ferrule body  516  includes one or more facets  508 . The facets  508  can be either concave, convex, or a combination thereof. In one embodiment, the facets  508  are grooves or depressions arranged generally parallel to the longitudinal axis. In another embodiment, the facets  508  are ridges or protrusions. The facets  508  provide a number of functions, such as aerodynamics, stability of the expandable broadhead  500  as it penetrates a target, and the release of fluid pressure that may accumulate in front of the expandable broadhead  500 . 
     The plurality of blades  504   a  and  504   b  of the present invention depicted in the exemplary broadhead design  500  can be referred to generically as cutting blades. In a preferred embodiment, the cutting blades  504   a  and  504   b  are rear deploying blades. As used herein, “rear deploying” refers to rearward translation of blades  504   a  and  504   b  generally along a longitudinal axis of the ferrule body  516  and outward movement of a rear portion of the blades  504   a  and  504   b  away from the longitudinal axis. The rearward translation can be linear, curvilinear, rotational or a combination thereof. In a preferred embodiment of the present invention, the rear deploying blades  504   a  and  504   b  are attached to the ferrule body  516  by a mechanism  510  that allows the blades  504   a  and  504   b  to move outward in a camming manner from the ferrule body  516  by a rearward translation that causes interaction between the ferrule body  516  and the blades  504   a ,  504   b . In certain embodiments, the pivot feature  510  is a threaded fastener, including but not limited to a pin, which can be removed to permit replacement of the blades  504   a  and  504   b.    
     In a preferred embodiment of the invention, the rear portion of a rear deploying blade  504   a  or  504   b  remains on the same side of a blade pivot axis in both the retracted and deployed configurations for the rear deploying blade  504   a  or  504   b . An example of the movement of the rear deploying blades  504   a  and  504   b  is illustrated by U.S. Pat. No. 8,197,367, hereby incorporated herein in its entirety by reference. The shock-absorbing retainer  514  assists in retaining the rear deploying blades  504   a  and  504   b  in the retracted configuration until impact. 
     In a preferred embodiment, as illustrated by  FIGS. 5A-5C , the rear deploying blades  504   a  and  504   b  include a blunt impact edge  506   a  and  506   b  and a sharp cutting edge  512   a  and  512   b . In certain embodiments, including the exemplary embodiment illustrated in  FIG. 5B , the rear deploying blades  504   a  and  504   b  include one or more cutouts  520   a  and  520   b . The cutouts  520   a  and  520   b  serve to reduce the weight of the rear deploying blades  504   a  and  504   b , to increase the strength and/or flexibility of the blades  504   a  and  504   b , or to perform other functions. 
     In one or more preferred embodiments of the present invention, in the retracted configuration of the plurality of rear deploying blades  504   a  and  504   b , the blunt impact edge  506   a  and  506   b  is positioned exterior to the ferrule body  516 . Each of the plurality of rear deploying blades  504   a  and  504   b  is releasably coupled to the shock-absorbing retainer  514  to retain the rear deploying blades  504   a  and  504   b  in the retracted configuration. When the impact edge  506   a  and  506   b  contacts an object, the blades  504   a  and  504   b  release from the retainer  514  and the blades  504   a  and  504   b  are displaced rearward. As the blades  504   a  and  504   b  move rearward, the blades  504   a  and  504   b  move from the retracted configuration to the deployed configuration through camming between the blades and ferrule body. 
     Different deployment configurations are desirable for a variety of reasons, such as, for example, the nature of the target or type of game being hunted. In one embodiment of the present invention, the threaded fastener  510  preferably used as the pivot feature on the present invention&#39;s expandable broadhead  500  permits quick and easy substitution of blades  504   a  and  504   b  having different deployment configurations. In some embodiments, it may be advantageous to attach cutting blades having different deployment profiles to a single ferrule body  516 . 
     In a preferred embodiment of the present invention, the shock-absorbing retainer  514  is made from a resilient or elastomeric material that absorbs some of the impact force between the rear deploying blades  504   a  and  504   b  and the ferrule body  516  in the deployed configuration of the blades  504   a  and  504   b . In the preferred embodiment, the shock absorbing properties of the retainer  514  reduces blade failure in the deployed configuration. In another embodiment, the retainer  514  plastically deforms upon impact of the cutting blades  504   a  and  504   b . The diameter of the retainer  514  can be selected based on the degree of impact absorption required, the configuration of the cutting blades  504   a  and  504   b , and other factors. In an exemplary embodiment of the present invention, the retainer  514  can be constructed as a metal snap ring made from a softer metal than the rear deploying blades  504   a  and  504   b . In another exemplary embodiment, the retainer  514  is constructed from a low surface friction material, such as, for example, nylon, HDPE (high-density polyethylene) or PTFE (polytetrafluoroethylene), to facilitate blade deployment. 
     In certain preferred embodiments of the invention, different types of shock-absorbing retainers can be used in the expandable broadhead design, as illustrated by the exemplary embodiment  550  of the present invention depicted in  FIG. 5C , which features the same chisel tip  502  as the broadhead design  500  depicted in  FIGS. 5A and 5B , but utilizes a different type of shock-absorbing retainer  530 . 
     In another preferred embodiment of the present invention, the shock-absorbing retainer  514  is made from a polymeric material, and is used in conjunction with an O-ring to retain the rear deploying blades  504   a  and  504   b  in place during flight until impact. The polymeric material should be flexible enough to withstand normal handling without any breakage issues. Furthermore, the material must be flexible enough that it doesn&#39;t break when the retainer  514  is pushed into position during assembly. At the same time, the material of the retainer  514  should be brittle enough upon impact so that it releases the blades  504   a  and  504   b  in a rapid loading impact situation. The descriptive name for a material possessing these qualities is “strain rate sensitive.” In a preferred embodiment of the present invention, the polymeric material is polypropylene. 
     The components of the expandable broadhead  500  can be manufactured using a variety of techniques. In one embodiment of the present invention, the ferrule body  516  and/or the rear deploying blades  504   a  and  504   b  are made using metal injection molding techniques. In another embodiment, the ferrule body  516  and/or the rear deploying blades  504   a  and  504   b  are manufactured using powder injection molding techniques. The powder mixtures used in either the metal injection molding or powder injection molding processes can include metals, ceramics, thermoset or thermoplastic resins, and composites thereof. Reinforcing fibers can optionally be added to the powder mixture. 
     In other embodiments of the present invention, the ferrule body  516  and/or the rear deploying blades  504   a  and  504   b  are made using other molding techniques, such as injection molding. The molding materials can include metals, ceramics, thermoset or thermoplastic resins, and composites thereof. Reinforcing fibers can optionally be added to the molding mixture. Suitable reinforcing fibers include glass fibers, natural fibers, carbon fibers, metal fibers, ceramic fibers, synthetic or polymeric fibers, composite fibers, or a combination thereof. 
     In certain embodiments of the present invention, the ferrule body  516  is made from a material selected from the group consisting of aluminum, titanium, magnesium, and carbon-fiber reinforced polymer. In a preferred embodiment of the present invention, the ferrule body  516  is made from aluminum. In another preferred embodiment of the present invention, the ferrule body  516  is made from titanium. 
     In certain embodiments of the present invention, the rear deploying blades  504   a  and  504   b  are cut from a sheet or blank of blade stock material. The blade stock material can be made from various different steels, including tool steels, stainless steels, high speed steel, carbon steels, carbides, titanium alloys, tungsten alloys, tungsten carbides, as well as other metals or any other suitable material that a cutting blade  504   a  or  504   b  could be fabricated from. 
     The expandable broadhead designs  500  and  550  of the present invention, as illustrated by  FIGS. 5A-5C , also include a chisel tip  502 . In a preferred embodiment of the present invention, the chisel tip  502  is a pressed in insert that is inserted into the neck section  507  of the ferrule body  516 . 
     In certain preferred embodiments of the present invention, as depicted by the exemplary side view of expandable broadhead  600  in  FIG. 6A  and the exemplary side view of expandable broadhead  610  in  FIG. 6B , the expandable broadhead designs  600  and  610  may include a three-faceted chisel tip  602  and three rear deploying blades  604   a - c  releasably coupled to a shock-absorbing retainer  606  or  608 . 
       FIGS. 7A-7C  illustrate exemplary side and top views of a chisel tip  700  of a preferred embodiment of the present invention. In this preferred embodiment, the chisel tip  700  has three facets  710   a - c , as depicted by the top view of the chisel tip  700  illustrated in  FIG. 7C . 
       FIGS. 7D-7F  illustrate exemplary side and top views of a chisel tip  730  of another preferred embodiment of the present invention. In this preferred embodiment, the chisel tip  730  has four facets  740   a - d , as depicted by the top view of the chisel tip  730  illustrated in  FIG. 7F . 
     In certain embodiments of the present invention, the chisel tip  700  or  730  can be made from various different steels, including tool steels (M-2, S-7, and D-2), stainless steels (301, 304, 410, 416, 420, 440A, 440B, 440C, 17-4 PH, 17-7 PH, 13C26, 19C27, G1N4 and other stainless steels), high speed steel, carbon steels, carbides, titanium alloys, tungsten alloys, tungsten carbides, as well as other metals. In a preferred embodiment of the invention, the chisel tip  700  or  730  is made from stainless steel. The heightened density and weight of the larger steel structure of the chisel tip  700  or  730  in this embodiment, when compared to an aluminum or titanium (materials which are more lightweight and less dense than steel) ferrule body, leads to a center of mass on the projectile that has greater forward of center properties. Increasing the mass forward of center on a projectile is a well-established method of improving the flight characteristics of that projectile. 
     In certain embodiments of the present invention, the chisel tip  700  or  730  can be coated with a material selected from the group consisting of nickel, zinc, cadmium, and black oxide. In a preferred embodiment of the invention, the chisel tip  700  or  730  is coated with nickel. The tip can also be coated with a friction reducing coating such as a PTFE impregnated ceramic or fluoropolymer, PVD (physical vapor deposition) or CVD (chemical vapor deposition) ceramic type coating. 
     As illustrated by the exemplary embodiments displayed in  FIGS. 7A-C  and  FIGS. 7D-F , preferred embodiments of the chisel tips  700  and  730  incorporate a helical design pattern for the cutting edges of the chisel tip  700  or  730 &#39;s facets  710   a - c  and  740   a - d , respectively. This spiraling helical pattern is also illustrated by the cross-sectional views of the exemplary three-facet chisel tip embodiment  800  displayed in  FIGS. 8A-8E , as well as the cross-sectional views of the exemplary four-facet chisel tip embodiment  900  displayed in  FIGS. 9A-9E . The helical pattern of the three-facet chisel tip  800 &#39;s cutting edges  804   a - c , as well as the helical pattern of the four-facet chisel tip  900 &#39;s cutting edges  904   a - c , directs the air flow around the ferrule body in the preferred embodiments of the present invention. The directed air flow leads to increased rotation of the broadhead projectile and reduces the effects of side winds in flight, stabilizing the flight path of the projectile to improve its flight characteristics and leading to enhanced accuracy and precision of arrow shots. 
     In addition to the helical design pattern illustrated by the exemplary embodiments displayed in  FIGS. 7A-F ,  8 A-E, and  9 A-E, both the three-facet and four-facet exemplary embodiments illustrated in these figures also include concave faces for the facets of the chisel tips  800  and  900 . The concave facets of the chisel tips  800  and  900  in the preferred embodiments of the present invention lead to the points  802  and  902  of the chisel tips  800  and  900  and the cutting edges  804   a - c  and  904   a - d  separating the facets of the chisel tips  800  and  900  both being of a more acute angle than the cutting edges and point of a chisel tip with facets cut flat. The increased acuteness of the preferred embodiments&#39; concave chisel tips  800  and  900 &#39;s points  802  and  902  and cutting edges  804   a - c  and  904   a - d , respectively, improve the penetration of the points  802  and  902  of the chisel tips  800  and  900  into a target or game animal and increase the sharpness of the cutting edges  804   a - c  and  904   a - d.    
     Various embodiments of the present invention have varying numbers of cutting blades as well as different numbers of facets on the chisel tip. However, in preferred embodiments of the present invention, the number of facets of the chisel tip is a multiple of the number of cutting blades of the expandable broadhead. 
     For example, in a preferred embodiment, an expandable broadhead with two cutting blades would be tipped with a chisel tip with two, four, six, etc. facets. Such a preferred embodiment is illustrated by  FIGS. 10A-B , displaying an expandable broadhead  1000  with two cutting blades  1002   a - b  and a four-facet  1006   a - d  chisel tip  1004 . In another preferred embodiment, an expandable broadhead with three cutting blades would be tipped with a chisel tip with three, six, nine, etc. facets. Such a preferred embodiment is illustrated by  FIGS. 10C-D , displaying an expandable broadhead  1020  with three cutting blades  1022   a - c  and a three-facet  1026   a - c  chisel tip  1024 . However, other embodiments of the present invention can include any combination of an amount of cutting blades and number of chisel tip facets.  FIGS. 10E-F  illustrate an exemplary embodiment of an expandable broadhead  1040  that has two cutting blades  1002   a - b  and a three-facet chisel tip  1024 , and  FIGS. 10G-H  illustrate an exemplary embodiment of an expandable broadhead  1060  that has three cutting blades  1022   a - c  and a four-facet chisel tip  1004 . 
     In the preferred embodiments of the present invention, in which the number of facets of the chisel tip is a multiple of the number of cutting blades, by controlling the rotational angle of insertion of the chisel tip relative to the principal axes of the ferrule body, the facets of the chisel point can be positioned so that the cutting edges between the facets provide a complementary set of cutting edges to the primary cutting blades of the expandable broadhead. As illustrated by the exemplary view of the expandable broadhead design  1020  depicted in  FIG. 10D , the angle of rotation of the chisel tip  1024  in preferred embodiments of the present invention should be such that the cutting edges of the chisel tip  1024  approximately bisect the separation angle of the cutting blades  1022   a - c.    
     The complementary positioning of the chisel tip&#39;s cutting edges in relation to the cutting blades of the expandable broadhead in the preferred embodiments of the invention leads to several unique performance enhancements over previous expandable broadhead designs. The complementary placement of the chisel tip&#39;s cutting edges in relation to the cutting blades leads to a greater number of incisions made by the expandable broadhead, leading to maximum effectiveness in cutting. 
     Furthermore, deployment of the cutting blades works best when the leading blunt edges of those retracted blades strike the hide of a targeted game animal on impact. By offsetting the alignment of the chisel tip&#39;s cutting edges with the alignment of the rear deployed cutting blades, the preferred embodiments ensure that the blunt edges of the retracted blades strike uncut portions of the animal&#39;s hide, causing the retracted blades to effectively deploy and expose their sharp cutting edges. 
     In addition to the functional improvements of the chisel tip, in a preferred embodiment, the contours of the chisel tip are arranged and configured to flow into adjoining contours of the ferrule body, creating an aesthetically pleasing design. 
     In certain embodiments of the present invention, the expandable broadhead has a cutting diameter of about 1 inch to about 2.5 inches in diameter, when the blades are in an expanded position. In a preferred embodiment, the expandable broadhead has a cutting diameter of about 2 inches, when the blades are in an expanded position. In another preferred embodiment of the present invention, the expandable broadhead has a cutting diameter of about 1.5 inches, when the blades are in an expanded position. 
     In certain embodiments of the present invention, the expandable broadhead has a weight of about 75 grains to about 150 grains. In a preferred embodiment, the expandable broadhead has a weight of about 100 grains. In another preferred embodiment of the present invention, the expandable broadhead has a weight of about 125 grains. 
     The following Examples are only illustrative. It will be readily seen by one of ordinary skill in the art that the present invention fulfills all of the objectives set forth above. After reading the foregoing specification, one of ordinary skill will be able to effect various changes, substitutions of equivalents, and various other embodiments of the invention as broadly disclosed therein. It is therefore intended that the protection granted herein be limited only by the definition contained in the appended claims and equivalents thereof. 
     EXAMPLES 
     Example 1 
     An expandable broadhead  1100  with a chisel tip  1102  as illustrated by  FIGS. 11A-11G , that includes two side cutting blades  1104   a - b , a collar  1106 , and a four-facet chisel tip  1102  with concave facets and helical cutting edges. 
     Example 2 
     An expandable broadhead  1200  with a chisel tip  1202  as illustrated by  FIGS. 12A-12G , that includes two side cutting blades  1104   a - b , a collar  1106 , and a three-facet chisel tip  1202  with concave facets and helical cutting edges. 
     Example 3 
     An expandable broadhead  1300  as illustrated by  FIGS. 13A-13B , having two side cutting blades  1104   a - b , a collar  1306 , and a four-facet chisel tip  1102  with concave facets and helical cutting edges, as shown in  FIGS. 11C-G . 
     Example 4 
     An expandable broadhead  1400  as illustrated by  FIGS. 14A-14B , having two side cutting blades  1104   a - b , a collar  1306 , and a three-facet chisel tip  1202  with concave facets and helical cutting edges, as shown in  FIGS. 12C-G . 
     Example 5 
     An expandable broadhead  1500  as illustrated by  FIGS. 15A-15B , having three side cutting blades  1504   a - c , a collar  1106 , and a three-facet chisel tip  1202  with concave facets and helical cutting edges, as shown in  FIGS. 12C-G . 
     Example 6 
     An expandable broadhead  1600  as illustrated by  FIGS. 16A-16B , having three side cutting blades  1504   a - c , a collar  1106 , and a four-facet chisel tip  1102  with concave facets and helical cutting edges, as shown in  FIGS. 11C-G . 
     Example 7 
     An expandable broadhead  1700  as illustrated by  FIGS. 17A-17B , having three side cutting blades  1504   a - c , a collar  1306 , and a three-facet chisel tip  1202  with concave facets and helical cutting edges, as shown in  FIGS. 12C-G . 
     Example 8 
     An expandable broadhead  1800  as illustrated by  FIGS. 18A-18B , having three side cutting blades  1504   a - c , a collar  1306 , and a four-facet chisel tip  1102  with concave facets and helical cutting edges, as shown in  FIGS. 11C-G .