Patent Publication Number: US-9903693-B2

Title: Broadhead with extendable blades

Description:
This application claims priority from U.S. patent application Ser. No. 61/584,797, filed Jan. 9, 2012, entitled “Broadhead With Extendable Blades” which is a continuation-in-part of and claims priority from U.S. patent application Ser. No. 61/582,363, filed Jan. 1, 2012, entitled “Broadhead With Extendable Blades,” both of which are incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to arrowheads and, more specifically, to a type of arrowhead referred to as a broadhead, having an arrow tip and blades that are tucked in during flight and are deployed when the arrow strikes its target. 
     BACKGROUND OF THE INVENTION 
     Broadhead arrowheads are well known in the bow hunting art. In particular, broadheads having auxiliary blades that deploy when the arrow strikes its target are also well known, and will be referred to generally as expanding or expandable broadheads. 
     Expandable broadheads allow an arrowhead to have a relatively small and streamlined configuration during flight to enhance accuracy. Upon striking a target, a set of auxiliary blades expand for the purpose of enlarging the entrance wound, enabling a more certain and humane kill. 
     U.S. Pat. No. 6,517,454 (Barrie et al) discloses a broadhead with sliding, expanding blades. The blades are pivotally attached to the arrowhead and are held closed in flight by a rubber restraint. When the arrowhead penetrates the target, the forward edges of the blades also contact the target forcing the blades rearward, severing the restraint and allowing the trailing edges of the blades to dispose outward to a V-shape thereby exposing the sharpened edges of the blades. 
     Published U.S. Patent Application 2009/0029811 (Bolen III) discloses an expandable broadhead and blades therefor. In Bolen, the auxiliary blades face forward with the pivots for them positioned at the rear of the arrowhead. The blades are configured to fracture if, when they expand and strike the target, they encounter a hard or solid object, such as a bone. 
     U.S. Pat. No. 6,554,727 (Armstrong et al) discloses a deflection-resistant arrowhead having both fixed and mechanically expandable blades. In Armstrong, the blades have a rearward pivot and face forward, and are held in place by a severable restraint during flight. When the arrowhead strikes the target, a forward edge of each expandable blade also contacts the target forcing the blades rearward around the pivot to open and thus expose the sharpened edges of the blades. 
     U.S. Pat. No. 6,595,881 (Grace Jr.) discloses an expanding blade-archery broadhead with the blades, in their stored position, facing forward and having a rear or trailing pivot. A sliding collar deploys forward when the arrowhead strikes its target causing the blades to extend and pivot rearward, exposing the sharpened blade edges. 
     U.S. Pat. No. 6,669,586 (Barrie et al) discloses an expanding broadhead having expandable blades with forward pivots attached to a collar that is slidably mounted within the arrowhead body. When the arrowhead strikes the target, the mounting ring is brought into contact with a camming surface within the arrowhead which deploys the sharpened edges of the blades by severing the restraint. 
     U.S. Pat. No. 6,910,979 (Barrie et al) discloses an expandable broadhead with expandable blades having arcuate slots formed thereon. The blades are mounted to the arrowhead with a guide boss positioned within the slot. When the arrowhead penetrates the target, the lead edge of each blade comes into contact with the target of the blade is forced along the arcuate slot to deploy with the sharpened blade edges exposed. 
     U.S. Pat. No. 7,226,375 (Sanford) discloses an expandable arrow broadhead for attachment to one end of an arrow shaft. A set of rearward extending blades, pivoted at their front end are attached to an arrowhead and are held in place by a rubber band. When the arrow strikes its target, a collar within the arrowhead slides forward contacting the blades forcing them outward with sufficient force to sever the rubber band and deploy the sharpened cutting edges. 
     The foregoing references are incorporated herein in their entirety. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an arrowhead with expandable blades which, in their unextended position, provide an arrowhead profile that is configured to be accurate in flight. 
     It is a further object of the present invention to retain the expandable blades during flight without requiring the use of a retaining member. 
     It is a further object of the present invention to provide blades that are of greater length than those normally associated with expandable broadheads. 
     It is a further object of the present invention to provide a mechanism that quickly, reliably and accurately deploys the blades to a cutting position in a minimum amount of time. 
     It is a further object of the present invention to provide these blades in cross-configurations such that the actuating surface and cutting surface of each blade deploy on opposite sides of the arrowhead. 
     While the following describes a preferred embodiment or embodiments of the present invention, it is to be understood that this description is made by way of example only and is not intended to limit the scope of the present invention. It is expected that alterations and further modifications, as well as other and further applications of the principles of the present invention will occur to others skilled in the art to which the invention relates and, while differing from the foregoing, remain within the spirit and scope of the invention as herein described and claimed. Where means-plus-function clauses are used in the claims such language is intended to cover the structures described herein as performing the recited functions and not only structural equivalents but equivalent structures as well. For the purposes of the present disclosure, two structures that perform the same function within an environment described above may be equivalent structures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and further objects of the present invention will be best understood upon consideration of the accompanying drawings in which: 
         FIG. 1  is a top plan view of a broadhead arrow after penetration of a target, but prior to the deployment of the blades; 
         FIG. 2  is the broadhead arrow of  FIG. 1  after the blades have been deployed; 
         FIG. 3  is a perspective view of the ferrule of  FIG. 1 ; 
         FIG. 4  is front elevation of the ferrule of  FIG. 3 ; 
         FIG. 5  is a side elevation of the ferrule of  FIG. 3 ; 
         FIG. 6  is a view along D-D of  FIG. 5 ; 
         FIG. 7  is an enlargement of detail A in  FIG. 6 ; 
         FIG. 8  is a bottom view of the ferrule of  FIG. 3 ; 
         FIG. 9  is a view along  9 - 9  of  FIG. 8 ; 
         FIG. 10  is a perspective view of a broadhead blade 
         FIG. 11  is a plan view of the blade of  FIG. 10 ; 
         FIG. 12  is a partial perspective view of a broadhead blade with an impact bar; 
         FIG. 13  is an enlarged view of detail A of  FIG. 12 ; 
         FIG. 14  is a lateral view of the blade of  FIG. 12 ; 
         FIG. 15  is an enlarged view of detail C of  FIG. 14 ; 
         FIG. 16  is a partial perspective view of a broadhead blade showing an alternate attachment for an impact bar; 
         FIG. 17  is an enlarged view of detail B of  FIG. 16 ; 
         FIG. 18  is a perspective view of a tip blade; 
         FIG. 19  is a top plan view of the blade of  FIG. 18 ; 
         FIG. 20  is an exploded perspective view of a broadhead including the features described herein; 
         FIG. 21  is a perspective view of a fastener used to assemble the broadhead; 
         FIG. 22  is a plan view of the fastener of  FIG. 21 ; 
         FIG. 23  is a lateral perspective view of an assembled broadhead with the blades in the tucked or flight position; 
         FIG. 24  is a perspective view of the broadhead in flight with the blades in the tucked or flight position; 
         FIG. 25  is a perspective view of the broadhead of  FIG. 22  with the blades deployed; 
         FIG. 26  is a partial sectional view of  FIG. 21 ; 
         FIG. 27  is a partial sectional view of  FIG. 23 ; 
         FIG. 28  is a schematic view of a variation of a broadhead with the blades in the tucked or flight position; and 
         FIG. 29  is a schematic view of the broadhead of  FIG. 24  with the blades in the expanded position. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring now to  FIG. 1 , the numeral  10  indicates generally a broadhead arrowhead referred to throughout as “a broadhead.” Broadhead  10  has a proximal end  14  to which a threaded shaft  16  is formed. Shaft  16  is used to thread broadhead  10  onto an arrow shaft. Body  12  has a distal end  18  at which a blade mount  20  is formed as a site for the attachment of tip blade  22 . In the embodiment shown, broadhead  10  has a left expandable blade  24  and a right expandable blade  26  pivotally attached to body  12 . As seen in  FIG. 1 , left blade  24  has a lead segment  28  terminating at a lead edge  30  to which an impact bar  32  is attached. 
     In like fashion, right blade  26  has a lead segment  34  terminating at a lead edge  36  to which an impact bar  38  is attached. 
     Left blade  24  has a trailing blade segment  40  having a planar leg  42  along with a sharpened edge  44  is formed. In this embodiment, sharpened edge  44  is formed outboard of or in a direction away from body  12 . 
     In like fashion, blade  26  has a rear trailing segment  46  having a planar arm  48  on which is formed a sharpened edge  50 . As with sharpened edge  44 , sharpened edge  50  is formed outboard or in a direction away from body  12 . 
     As seen in  FIG. 1 , broadhead  10  is shown as having made contact with and penetrating target  52 . As seen in  FIG. 1 , arms  24  and  26  are in their closed or in-flight position. In this position, blades  24 ,  26 , present a balanced configuration that contributes to the stability and accuracy of an arrow&#39;s flight with broadhead  10  attached thereto. 
     Referring to  FIG. 2 , broadhead  10  is shown having penetrated target  52  to a distance sufficient to put impact bars  32 ,  38  into contact with target  52  to deploy left and right trailing blade segments  42 ,  48  and, thereby, sharpened edges  42 ,  50 . In this position, broadhead  10  will continue its travel into target  52  to engage sharpened edges  44 ,  50 , thereby increasing the size of the impact zone. 
     As seen in  FIG. 2 , body  12  has a rubber o-ring  54  mounted thereto to act as a retainer for blades  24 ,  26  in their closed position and to act as stop and to absorb the impact created when blades  24 ,  26  deploy. As seen in  FIG. 1 , right blade  26  has a brace edge  56  formed at the rear of right lead segment  34 . As will be described hereinbelow, as right blade  26  pivots to deploy trailing segment  48 , stop segment  56  will move toward and contact shock absorber  54 . It should be understood that a similar lock edge is formed on left blade  24 . Shock absorber  54  may be formed from a heavy rubber or otherwise flexible material and is held in place on body  12  by retainer  58 . Shock absorber  54  not only damps the rearward motion of blades  24 ,  26 , it also provides a stop to lock the blades in their deployed position such that contact between sharpened edges  44 ,  50  and target  52  does not cause trailing arms  42 ,  48  to move or otherwise collapse. 
     Referring now to  FIG. 3 , a perspective view of body  12  is shown. Blade mount  20  has a arrow tip blade mount slot  60  formed therethrough, partially along body  12 . A centrally positioned blade mount slot  62  is also formed in body  12 . Also shown in  FIG. 3  is threaded shaft  16  used to mount body  12  to an arrow shaft. 
     Referring now to  FIG. 4 , blade mount slot  62  is more clearly shown. Also as seen in  FIG. 4 , arrow tip blade mount  20  has a mounting aperture  64  through which a fastener can be passed to secure an arrow tip in place. 
     Referring now to  FIG. 5 , a lateral view of body  12  is shown with arrow tip blade mount slot  60  shown in greater detail. Also shown are upper blade mount bore  66  and blade lock bore  68 . As will be shown hereafter, bore  66  allows a fastener to be inserted into body  12  to retain left blade  24  and right blade  26 . 
     Referring now to  FIG. 6 , a sectional view taken along lines  6 - 6  of  FIG. 5  shows bore  66  is preferably formed as a blind bore into which a fastener may be inserted and attached. In like fashion, bore  68  is also formed as a blind bore. Preferably bores  64  and  68  are positioned on opposite sides of body  12 . 
     Referring now to  FIG. 7 , an enlarged view of detail A of  FIG. 6  is shown wherein it can seen that the lead portion  70  of bore  66  is internally threaded as is the lead portion  72  of bore  68 . These threaded portions provide the means by which fasteners such as that shown in  FIGS. 21 and 22  may be threaded into bores  66 ,  68  and retained in position. This configuration provides a more symmetrical distribution of mass when broadhead  10  is assembled, enhancing accurate and predictable flight. 
     Referring now to  FIG. 8 , a lateral elevation of body  12  is shown, demonstrating blade tip mount slot aperture  64 . In this embodiment blade mount  20  has a countersink  70  to receive the head of a fastener screwed into aperture  64 , thus improving the aerodynamic quality of body  12 . 
     Referring now to  FIG. 9 , a view along  9 - 9  of  FIG. 8 , it can be seen that the interior of blade mount slot  62  has a flat, smooth, machined surface  72 . 
     It is a feature of the present invention that blades  24 ,  26  will be attached to body  12  in a stacked configuration, that is, with the blades touching one another. It is also a feature that the outermost surface of each blade will be in contact with machined surface  72  and flat machined surface  74  formed on the opposite side of slot  62 , as seen in  FIG. 8 . Machining both the blade surfaces and the slot surfaces decreases the friction realized when blades  24 ,  26  move not only with relation to each other but with relation to inner surfaces  72 ,  74  of body  12 . 
     Referring now to  FIG. 10 , the numeral  24  identifies the left blade showing the left lead segment  28 , left lead edge  30 , the left trailing segment  40 , the left trailing arm  42  and the sharpened edge  44 . Blade  24  also has a first mount tang  76  having an oval-shaped guide slot  78  formed therethrough. Blade  24  also has a mounting aperture  80  formed proximate trailing portion  40  and a retainer notch  82 . 
     Referring now to  FIG. 11 , a plan view of the blade of  FIG. 10  is shown, illustrating the relative placement of the foregoing blade elements. A central window W may be formed in blade  24  to reduce the weight of the blade. Weight is a concern, with a broadhead usually weighing  100  grains or less. 
     Referring now to  FIG. 12 , a variation of blade  24  is shown having impact bar  32  attached to lead segment  30 . As shown in  FIG. 13 , impact bar  32  is formed as a hemispherical rod segment having a flat bottom  84  and a curved upper surface  86 . 
     As best seen in  FIGS. 14 and 15 , impact bar  32  is attached to lead edge  30  such that a portion of impact bar  32  extends past the upper surface  88  of lead portion  28 . As seen in  FIG. 15 , rounded surface  86  is presented toward the target. The offset portion  90  of impact bar  32  may be adjusted to fit the desired aerodynamic characteristics of the broadhead, extending portion  90  past upper surface  88  provides for a larger impact surface area  86 . 
     Referring to  FIG. 16 , right impact bar  38  is shown attached to right lead segment  34  of right blade  26 . As seen in  FIGS. 16 and 17 , impact bar  38  is attached to lead edge  32  such that the offset portion  92  extends past upper surface  94  of blade  26 . In this fashion, when the blades are assembled, both impact bars  32  and  38  will have offset  90 ,  92  facing in the same direction with respect to the blades such that one surface of the blades, in flight, will present a smooth surface with impact bars  32 ,  38  being flush with one surface of each of the respective blades  24 ,  26  while the remaining portions of the impact bars  90 ,  92  will extend downward in the same direction away from blade surfaces  88  and  94 , respectively. 
     Referring now to  FIG. 18 , a perspective view of tip blade  22  is shown. Referring now to  FIG. 19 , it can be seen that tip blade  22  is formed in a generally triangular shape with arcuate sharpened edges  96 ,  98  extending from a tip apex  100  downward to a tip base  102 . A mounting aperture  104  is formed through tip blade  22 . 
     Referring now to  FIG. 20  broadhead  10  is shown in an exploded perspective view. As seen, tip blade  22  is shown removed from tip blade slot  60 . In like fashion, blades  24 ,  26  are shown removed from slot  62 , and o-ring  54  is shown removed from body  12 . 
     Referring now to  FIGS. 21 and 22 , a preferred form of fastener  138  is shown. In this embodiment, fastener  138  has a head  140  and a shank  142 , with head  140  having machine threads  144  formed thereon and shank  142  having a smooth surface. Slot  1465  allows fastener  138  to be turned by a screwdriver. When threaded into bores such as  66 ,  68 , threads  144  engage threaded bore portions  70 ,  72 , while shank  142  presents a smooth surface around which blades  24 ,  26  can pivot. 
     Referring now to  FIG. 23 , broadhead  10  is shown assembled, with left and right blades  24 ,  26  in their “tucked” or flight configuration. As shown, broadhead  10  is not yet attached to an arrow shaft, so threaded mount  16  is exposed. Bore  64  is visible, as is the head of a threaded fastener  138 , while bore  68  is not. O-ring  54  is shown, held in place by shoulder  106  formed on body  12 . 
     Referring now to  FIG. 24 , broadhead  10  is shown as it appears in flight, with blades  24 ,  26  in their tucked or flight positions. 
     Referring now to  FIG. 25 , broadhead  10  with blades  24 ,  26  deployed as they would be after broadhead  10  has struck a target, with blades  24 ,  26  held in that position by contact with o-ring  54 . 
     Referring now to  FIG. 26  a partial sectional view is shown, with a portion of body  12  removed to illustrate the assembly of blades  24 ,  26 . In this configuration blades  24 ,  26  are stacked such that the lateral surfaces of blades  24 ,  26  slide over each other. In this view, the bottom surface of blade  24  rests upon machined surface  72  of blade mount slot  62  and it should be understood that the upper surface of blade  26  is in contact with similar machined surface  76 . 
     It should also be understood that blades  24 ,  26  are assembled as mirror images of each other and share the same structural configuration. 
     When in their “tucked” or flight configuration, retainer notches  82 ,  82 ′ engage o-ring  54  and hold blades  24 ,  26  in place, and keep sharpened edges  44 ,  50  in their swept-back position. Fastener  138  is passed through slots  78 ,  78 ′ and shank  142  provides a pivot surface for blades  24 ,  26 . In a variation of the foregoing, bore  68  can be positioned on body  12  to allow fastener  138  to pass through apertures  80 ,  80 ′ to prevent blades  24 ,  26  from deploying, allowing an archer to conduct target practice and determine the flight characteristics of broadhead  10  prior to its striking a target but without deploying the blades, and is an added safety feature keeping the blades from deploying during handling of broadhead  10 . 
     Referring now to  FIG. 27 , broadhead  10  is shown in its deployed, or after-strike configuration. Blades  24 ,  26  are expanded outward, with sharpened edges  44 ,  50  facing forward when having struck the target. When contact with lead edges  34 ,  36  forces blades  24 ,  26  to pivot, both are moved rearward along slots  78 ,  78 ′, constrained by fastener  138 , until rear blade edges  108 ,  110  move into contact with o-ring  54 . In this manner, o-ring  54  acts as a stop to keep blades  24 ,  26  and, thus, sharpened edges  44 ,  50  held in place with sufficient force to facilitate penetration of the target, while damping the motion of blades  24 ,  26  as their pivotal and sliding motion comes to an abrupt halt. 
     Referring now to  FIG. 28 , a variation of the present invention is disclosed. Broadhead  112  has a body  114 , a tip blade slot  116 , a tip blade  118 , a threaded mounting shaft  120  and an o-ring  122  mounted to body  114 . Broadhead  112  also has left and right blades  124 ,  126  mounted to body  114  substantially as described above with respect to broadhead  10 . 
     In this embodiment. however, blades  124 ,  126  have a somewhat different configuration. Both are more steeply angled (at angle A) to body  114 , and lead portion  128  of blade  124  extends outward a distance D 1  from body  114 , while lead portion  130  of blade  126  extends an equal distance D 2  This presents a larger impact surface for target  132  and one where the increased angle facilitates rapid deployment. 
     In addition, the relatively large angle A creates a larger moment about the pivots for blades  124 ,  126 , exerting more force over a relatively short distance, pushing sharpened portions  134 ,  136  to not only deploy more quickly, but with greater cutting force, overcoming some of the momentum lost when an arrow strikes its target and slows as it penetrates. 
     As seen in  FIG. 29 , it is expected that this configuration will cause sharpened portions  134 ,  136  of blades  124 ,  126  to deploy further in advance of contact with target  132  by distance D 3 . This allows tip  118  to penetrate deeper before blades  124 ,  126  deploy, for those applications where deeper penetration is an advantage for hunting certain types of game. In this configuration broadhead  112  exhibits characteristics similar to those of fixed-blade broadheads. 
     The foregoing disclosed embodiments provide cuts of up to about 2⅜ inches, believed to be larger than those created by existing broadheads. Manufacturing the broadhead components from highly machined and polished metal provides for a lightweight arrowhead with flight characteristics contributing to stable, accurate and predictable flight, and more humane kills. 
     This is achieved while still presenting a head configuration that successfully attains accurate flight. Changing broadheads for different hunting applications is facilitated by the universal-type screw mount utilized to mount broadhead  10  to an arrow shaft.