Patent Publication Number: US-11656064-B2

Title: Broadhead

Description:
BACKGROUND 
     When hunting with a bow, a hunter attempts to make an arrow accurately hit and efficiently travel through a vital region of a target animal. However, a common problem for hunters is that animals, particularly big game, can travel several miles before expiring from a lethal arrow wound. This means that to harvest the animal, the hunter may be required to track and locate the animal over a long distance. 
     When tracking the animal, a hunter searches for signs such as blood trails from the animal. However, the animal&#39;s body may naturally reduce an amount of blood loss after the lethal shot, which can make it difficult or impossible to track the animal based on blood trails. Many times, this results in a loss of the animal. 
     A broadhead is an arrow component disposed at a forward tip of the arrow. The broadhead generally has a cross-section that extends wider (a distance orthogonal to a longitudinal axis of the arrow), than a shaft of the arrow. An advantage of using a broadhead includes an increased wound channel within a successfully hit target animal, which in turn increases an amount of blood loss and an amount of damage done to the target animal. This increased wound channel leads to improved tracking of the animal and a faster and more humane expiration for the animal. 
     When designing a broadhead, a manufacturer considers features such as a cutting diameter of the broadhead (e.g., an effective size of a wound channel), how the broadhead affects proper and consistent flight from a bow to a target, penetration abilities of the broadhead, and durability of the broadhead. A broadhead that improves upon one of more of these features would provide a hunter with a better hunting experience by improving tracking of a target animal and may provide a more humane harvest of the target animal by accelerating expiration of the animal. 
     This Background introduces a selection of concepts in a simplified form that are further described below. This Background is not an admission of prior art and should not be considered as such. 
     SUMMARY 
     This disclosure incorporates by reference provisional application No. U.S. 62/714,036 filed on Aug. 2, 2018. This disclosure describes a broadhead that is designed for increased internal hemorrhaging and external blood seepage of a target animal. The described broadhead may improve, or minimally affect, arrow flight and accuracy. Additionally, the broadhead may be formed as a single piece and without moving parts to avoid structural vulnerabilities and reduce variations in manufacturing and flight performance. Any reference herein to an “arrow” is intended to include an archery arrow, a crossbow bolt, and a crossbow arrow. Furthermore, the broadhead described herein may be used in any type of ballistic. 
     In an example embodiment, a broadhead includes a first portion, as defined along a longitudinal axis of the broadhead. The first portion includes multiple cutting walls that extend radially (outwardly) from the longitudinal axis and define a first plurality of voids between the cutting walls. The outer edges of the cutting walls form edges of a generally pyramid-shaped volume that includes the first portion and the first plurality of voids. In other words, the outer edges of the cutting walls form a portion of a wireframe of the pyramid shape, not including edges of a base of the generally pyramid-shaped volume. The broadhead also includes a second portion, as defined along the longitudinal axis, that abuts the first portion. The second portion includes multiple concave lobes defining a second plurality of voids. The concave lobes have an inner surface that extends radially outward from the first end along the longitudinal axis to an opposite, second end of the second portion. 
     In another example embodiment, a broadhead includes a plurality of cutting walls extending radially from a longitudinal axis. The plurality of cutting walls form edges of a generally pyramid-shaped volume and define a first plurality of voids between the cutting walls. The broadhead also includes a plurality of concave lobes defining a second plurality of voids. Respective edges of the plurality of lobes extend between two of the plurality of cutting walls. In some implementations, the edges of the lobes form an arc that curves toward a rearward end of the broadhead. 
     In another example embodiment, a broadhead includes a plurality of cutting walls extending from a chisel point and forming edges of a generally pyramid-shaped volume, with the chisel point being a top of the generally pyramid-shaped volume. The plurality of cutting walls define a first plurality of voids between the cutting walls. The broadhead also includes a plurality of concave lobes that define a second plurality of voids that are in communication with the first plurality of voids. The plurality of concave lobes have respective edges extending between two of the plurality of cutting walls to form respective outer edges of the concave lobes. 
     This Summary introduces a selection of concepts in a simplified form that are further described below in the Detailed Description. As such, this Summary is not intended to identify essential features of the claimed subject matter, nor is it intended to be used to narrow the scope of the claimed subject matter. One or more of the described features may be included in an implementation of a broadhead. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description is described with reference to the accompanying figures. Entities represented in the figures may be indicative of one or more entities and thus reference may be made interchangeably to single or plural forms of the entities in the discussion. 
         FIG.  1    is a perspective view of an example broadhead. 
         FIG.  2    is a side view of the example broadhead of  FIG.  1   . 
         FIG.  3    is another side view of the example broadhead of  FIG.  1   . 
         FIG.  4    is another side view of the example broadhead of  FIG.  1   . 
         FIG.  5    is a top view of the example broadhead of  FIG.  1   . 
         FIG.  6    is a bottom view of the example broadhead of  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION 
     Overview 
     The described embodiments of broadheads improve upon conventional broadheads. The design features of the described embodiments result in a broadhead that causes an increased wound channel in a target animal by scooping flesh of the target animal away from a longitudinal axis of the broadhead as the broadhead travels through the target animal By increasing the wound channel, the target animal loses blood more quickly, which can accelerate the expiration process and improve tracking of the animal. 
     In a particular embodiment, the broadhead has a forward-most end formed into a chisel point. Three triangular-shaped cutting walls extend rearward and radially outward from the chisel point. The cutting walls define voids between one another that are shaped as triangular prisms. Each of the cutting walls has an outer edge that functions as a forward attack cutting edge to assist the broadhead with penetrating through animal mass. At a rearward end, the outer edges of the cutting walls meet respective rear attack cutting edges at respective attack points, which define outermost points of the broadhead. The rear attack cutting edges form at least a portion of an edge of a respective concave lobe. The concave lobes define another set of voids that are in communication with the void between the cutting walls. Each concave lobe, respectively, forms an outer surface of a cone, a sphere, an ellipsoid, or a paraboloid extending radially outwardly from a longitudinal axis of the broadhead. The voids between the cutting walls and the other set of voids are symmetric about a plane that intersects a longitudinal axis of the broadhead. The broadhead further includes a post to couple the broadhead to an arrow. 
     Example Implementation 
       FIGS.  1 - 6    illustrate an example implementation of a broadhead  100 . The broadhead  100  includes a first portion  102  and a second portion  104 , as defined along a longitudinal axis  106 . The broadhead may also include a post  108  for coupling the broadhead  100  to an arrow shaft. The broadhead  100  may be formed as a single piece of material such that the first portion  102  and the second portion  104 , and optionally the post  108 , are integrally coupled. For example, the first and second portions  102 ,  104  can be formed from a common substrate. In some of these embodiments, the broadhead  100  is free from seams or joints between the first portion  102  and the second portion  104 . The broadhead  100  may be formed via a casting process using a mold or may be formed via removing a portion of material from a block of material. The broadhead  100  may, for example, comprise one or more of steel, stainless steel, titanium, high-carbon metal, graphene, carbon steel, tungsten carbide, iron, chromium. The broadhead  100  may also be chemically treated to resist oxidation, which may include enveloping the broadhead  100  in a film. 
     The first portion  102  may comprise a plurality of cutting walls  110  that extend radially from the longitudinal axis  106 . The broadhead  100  may include 2, 3, 4, 5, 6, 7, or more cutting walls  110 . The cutting walls  110  define respective ones of a plurality of voids  112  between the cutting walls  110 . In some embodiments, some or all of the voids  112  are substantially shaped as a triangular prism (e.g., pyramidal volume), as in the embodiment of the broadhead  100  shown. The plurality of cutting walls  110  may form edges of a generally pyramid-shaped volume that includes the plurality of voids  112 . 
     The second portion  104  may have a first end  114  abutting the first portion  102 . The second portion  104  may comprise a plurality of concave lobes  116  that define another plurality of voids  118 . The plurality of concave lobes  116  may each have an inner surface  120  that extends radially outward from the first end  114  along the longitudinal axis  106  to an opposite, second end  122  of the second portion  104 . In other words, the concave lobes  116  may have a radial thickness that is relatively small at the first end  114  and a radial thickness that is relatively large proximate to the second end  122 . 
     The cutting walls  110  may include two opposite surfaces  124  (or “inner surfaces”) in contact with to the voids  112 . The inner surfaces  124  may be generally planar and may define a surface of a respective one of the voids  112 . In some embodiments, two opposite surfaces  124  of a same cutting wall  110  are parallel and/or symmetric surfaces (or planes). Additionally or alternatively, one or more of the inner surfaces  124  may be parallel to a radius extending from the longitudinal axis along the cutting wall  110 . Further, the cutting walls  110  may have a substantially uniform width a width that is substantially uniform over a majority of the length of the cutting wall  110 . 
     In some embodiments, one or more of the cutting walls  110  includes two radially outer surfaces  126 ,  128  that intersect at a forward attack cutting edge  130 . One or both of the radially outer surfaces  126 ,  128  can be coplanar with a corresponding radially outer surface  132 ,  134  of another one of the cutting walls  110 . In some embodiments, each cutting wall  110  includes two radially outer surfaces  126 ,  128  that intersect at a forward attack cutting edge  130  and each radially outer surface  126 ,  128  is coplanar with a corresponding radially outer surface  132 ,  134  of another cutting wall  110 . In such embodiments, a sharpening stone may be used to simultaneously sharpen one side of a forward attack cutting edge  130  of one cutting wall  110  and one side of a forward attack cutting edge  130  of another cutting wall  110 . 
     A portion of an inner surface  124  of a respective cutting wall  110  that abuts the first end  114  of the second portion  104  may form a generally smooth interface with, or transition to, a corresponding abutting portion of the inner surface  120  of a respective concave lobe  116 . In some embodiments, the abutting portion (at the first end  114 ) of the inner surface  120  of a concave lobe  116  meets two adjacent cutting walls  110  at an intersection  136 . 
     In some embodiments of the broadhead  100 , such as the one shown, the concave lobes  116  have outer edges  138  around and defining the concave inner surface  120  and the voids  118 . The outer edges  138  may be generally planar such that the broadhead can rest on the outer edge  138 . Respective upper ends of outer edges  138  can extend from outer edges of respective cutting walls  110 . The outer edges  138  may further extend between two of the plurality of cutting walls  110 . In some of these embodiments, the outer edges  138  form arcs that curve (with a generally forward concavity) toward the second end  122  of the second portion  104  (e.g., the rearward end of the broadhead  100 ) between adjacent cutting walls  110 . Additionally, in such embodiments, the voids  112  and the voids  118  are in communication and form a combined void. 
     In some embodiments, the voids  112 ,  118  collectively make up about 40% of a volume consisting of the first portion  102 , the second portion  104 , and voids  112 ,  118 . For example, the voids  112 ,  118  may make up between 35% and 45% of the volume. In other examples, the voids  112 ,  118  make up between 40% and 50% of the volume. Such a broadhead may be a  125  grain broadhead. 
     In some embodiments, the voids  112 ,  118  collectively make up about 57% of a volume consisting of the first portion  102 , the second portion  104 , and the voids  112 ,  118 . For example, the void  112 ,  118  may make up between 52% and 62% of the volume. In other examples, the voids  112 ,  118  make up between 45% and 70% of the volume. Such a broadhead may be a  100  grain broadhead. 
     A concave lobe  116  may include an outer edge  138  that meets an outer edge  140  of an adjacent concave lobe  116  at a rear attack cutting edge  142 . In embodiments where the outer edges  138 ,  140  are generally planar, one side of a rear attack cutting edge  142  can be sharpened (e.g., using a planar sharpening stone) simultaneously with sharpening one side of an adjacent rear attack cutting edge  142 . The rear attack cutting edge  142  may meet the forward attack cutting edge  130  at an attack point  144 , which may define an outermost point (radially) of the broadhead  100 . 
     In some embodiments, some or all of the outer edges  138  of the concave lobes  116  form a wireframe of a portion of volume shaped generally as a sphere, cone, ellipsoid, or paraboloid. For example, the outer edges  138  may extend as longitude lines of the three-dimensional shape. These longitudinal lines may be generally triangular, as shown, with a base of the triangle at the second end  122  of the second portion  104  and a tip opposite the base extending toward the first end  114  of the second portion  104 . Additionally or alternatively, the second end  122  of the second portion  104  may extend beyond the outer edges  138  of the concave lobes  116  in a longitudinal direction. The outer edges  138  of the concave lobes  116  may be the farthest extension of the broadhead  100  in a radial direction at any given angle from the longitudinal axis  106  (e.g., the outer edges  138  may define a largest width of the broadhead  100  at every angle from the longitudinal axis  106 ). 
     In some embodiments, some or each of the concave lobes  116  form a portion of an outer surface of a sphere, cone, ellipsoid, or paraboloid. In the case of a sphere, ellipsoid, or paraboloid, the concave lobe  116  is concave along at least two orthogonal axes. 
     The cutting walls  110  may be generally triangular with respective first points collectively forming a chisel point  146  of the broadhead  100 , a respective second point abutting respective upper ends of an edge  138  of a respective concave lobe  116  to form the attack point  144 , and a respective third point at a transition to an inner portion of the respective concave lobe (the intersection  136 ). 
     In some implementations, the broadhead  100  further includes a field tip abutting the first portion  102  on an end opposite the second portion  104 . In other words, the field tip abuts the first portion  102  at a forward end and the second portion  104  abuts the first portion  102  at a rearward end of the first portion  102 . 
       FIG.  5    includes reference planes (e.g., longitudinal planes)  148 ,  150  that extend radially from, and/or are parallel to, the longitudinal axis. In some implementations, one or more of the concave lobes  116  (and a corresponding one of the voids  118 ) is symmetric about the reference plane  150 . In other implementations, one or more of the concave lobes  116  includes an offset such that the concave lobe  116  is either asymmetric or is symmetric about a plane that has a non-zero angle (an angle between 0 and 180 degrees, excluding 0 and 180 degrees) with the longitudinal axis  106  of the broadhead  100 . In some embodiments, the offset causes the concave lobe  116  to be formed as if the second end  122  is twisted from the first end  114 . 
     Similarly, one or more of the voids  112  may be symmetric about a longitudinal plane  150 , asymmetric, or symmetric about a plane that has a non-zero angle (an angle between, but not including, 0 degrees and 180 degrees) with the longitudinal axis  106  of the broadhead  100 . 
     One or more of the cutting walls  110  may be symmetric about the reference plane  148 . In some of these embodiments, the two opposite surfaces  124  are generally parallel and planar. In other implementations, one or more of the cutting walls  110  includes an offset such that the cutting wall  110  is either asymmetric or is symmetric about a plane that has a non-zero angle (an angle between 0 and 180 degrees, excluding 0 and 180 degrees) with the longitudinal axis  106  of the broadhead  100 . In some embodiments, the offset causes the cutting wall  110  to be formed as if the chisel point  146  is twisted from the rearward-most portion of the cutting wall  110  abutting the first end  114  of the second portion  104 . 
     For embodiments where one or both of the concave lobes  116  and the cutting walls  110  include an offset, the offset may be, for example, between 1 and 5 degrees, between 1 and 15 degrees, or between 1 and 30 degrees. 
     CONCLUSION 
     Although the invention has been described in language specific to structural features and/or methodological acts, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as example forms of implementing the claimed invention.