Abstract:
The present invention relates to a family of arcuately expandable mechanical broadheads, wherein at least one thin metal strip may be curled around and restrained to the shaft of a broadhead that once released may unfurl into a cutting surface thereby enhancing, and adding to, the wound surface of a target mass.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    Pursuant to USC 35 §119(e) 3 the present application claims the benefit of a Provisional Application of Ser. No. 60/001,336 filed Nov. 1, 2007 by the present inventor, which is incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a mechanical broadhead. More specifically the present invention relates to a family of arcuately expandable mechanical broadheads. 
       BACKGROUND OF THE PRIOR ART 
       [0003]    Bow hunting is one of mans&#39; oldest arts and has benefited over time from technological improvements towards the fundamental equipment namely the bow and the arrow including various parts and materials relative thereto. Regarding the arrow, stone points have replaced bare wood. Metal points and metal broad heads replaced the stone points. Countless alterations have been made toward these and other fundamentals relative to this ancient, crowded art. 
         [0004]    One such improvement toward the typical metal broadhead is the so called, mechanical broadhead. These devices are found to possess a retracted state and a deployed state. During portage, loading, launch and flight, mechanical broadheads while in the retracted state will provide a minimal drag profile along the outermost longitudinal surface. Though, upon surface penetration of a target mass these type devices&#39; blades expand outward and provide greater cutting during penetration of the flesh of the game animal. The stated goal amongst a great many bow hunters is toward a mechanical broad that performs in flight as well as a field point. “Field points” describes an arrow used in practice as well as in competition and feature a bare, tapered point in which nothing extends outward of the lateral surface of the arrow shaft. Drag and deflection are held to a minimum with field points. 
         [0005]    U.S. Pat. No. 6,830,523 issued to Kuhn is substantially exemplary an “unfolding” type broadhead, in which the blades are hinged from a retracted state to an unfolded, deployed state. Well known in this crowded art, these type devices require heavy steel blades as a result of the impact received on impact and further, in that the trailing edge is not physically secured to the shaft of the broadhead nor that of the arrow shaft. Therefore the hinge, point of attachment and the blades themselves must be constructed so as to survive these very significant impact forces. 
         [0006]    The second type mechanical broadhead is the so called “sliding” type mechanical broadhead. U.S. Pat. No. 6,935,976 issued to Grace Jr. et al is exemplary relative to this type arrowhead. These type sliding broadheads are those in which the blades slide, upon impact, and ramp outward to a deployed state. These devices also suffer from the fact that careful attention much be given to the weight and strength of these type blades whereby upon impact they do not break or disintegrate upon impact. These type considerations, and responses thereto, invariably increase the weight of these type arrowheads. Further, while being deployed upon impact, the mass of these type blades cause the arrow to lose valuable speed thereby lessening the effect thereof. 
         [0007]    Another drawback relative to the above prior art broadheads is that impact upon bone can seriously hinder in not prevent further penetration of the target animal, in that these type broadhead are extremely rigid and would not contour along the terminal ballistic path if encountering bone, even as a glancing blow. These type broadheads&#39; blades would tend to “dig in” and be stopped by a significant, bony obstacle, which could result in a wounded, but not incapacitated animal. 
       SUMMARY 
       [0008]    The present invention relates to a family of mechanical broadheads in which retractable blades may be arcuately expanded from a wound to an unfurled, deployed position. The blades of the present invention may be coiled around a ferrule body and uncoiled upon impact. The blades may be restrained by a sliding outer body, bales, or by having been locked and cocked into place while under the tension of a coil spring and being extended though stationary slots. Blades of the present invention could be constructed of very thin sheet type metal, and much like a paper cut, would be able to slice through flesh with very little resistance due in part to the very thin profile of the cutting surface and body. Prior art mechanical blades are not capable of being constructed of paper thin metals for obvious reasons. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  shows a perspective view of the sliding outer body embodiment of the present invention while in the retracted state. 
           [0010]      FIG. 2  shows a perspective view of the sliding outer body embodiment of the present invention while in the deployed state. 
           [0011]      FIG. 3  shows a perspective view of a first alternate embodiment 
           [0012]      FIG. 4  shows a perspective view of the first alternate embodiment with the outer body in the deployed position with no blades present. 
           [0013]      FIG. 5  shows a perspective view of a second alternate embodiment in a cocked state. 
           [0014]      FIG. 6  shows a perspective view of the second alternate embodiment in the deployed or triggered state. 
           [0015]      FIG. 7  shows a side elevation of the blade ferule and point absent the cover of the second alternate embodiment. 
           [0016]      FIG. 8  shows the attachment point for the fixed axle of the second alternate embodiment. 
           [0017]      FIG. 9  shows the spring and winding chamber of the second alternate embodiment. 
           [0018]      FIG. 10  shows the stop bar assembly of the second alternate embodiment. 
           [0019]      FIG. 11  shows a bale secured arcuately expandable third alternate embodiment in a retracted state. 
           [0020]      FIG. 12  shows a bale secured arcuately expandable third alternate embodiment in a deployed state. 
           [0021]      FIG. 13  shows a bale secured arcuately expandable third alternate embodiment in a retracted state. 
           [0022]      FIG. 14  shows a bale secured arcuately expandable third alternate embodiment in a deployed state. 
       
    
    
     DESCRIPTION OF THE INVENTION 
     A First Embodiment of the Invention 
       [0023]    Referring to  FIG. 1 , a first embodiment a sliding outer body broadhead  10  of the present invention is shown and includes a sliding outer body  12 . Disposed along the outer surface of the sliding outer body  12  are fixed blades  14 . These blades along with being capable of slicing into a target mass will urge the outer body in a direction opposite to that of the flight of the arrow. A plurality of weight relief holes  18  are disposed along the body of the sliding outer body  12 . A locking clip  26  is shown attached to a point  28 . The point  28  is disposed on the leading distal end of the sliding outer body broadhead  10 . Still referring to  FIG. 1  a stop ring  32  is disposed on the broadhead rearward of the sliding outer body  12  and provides a stop relative to the sliding outer body&#39;s travel. 
         [0024]    Referring to  FIG. 2 , the first embodiment  10  is shown in a deployed state in which a plurality of flexible blades  20  are extended outward of a ferrule body  22 . The ferrule body  22  is pivotably disposed relative to the shaft of the broadhead. The blades  20  are secured to the ferrule body by corresponding set screws  24 . The blades would preferably be constructed of a thin metal not dissimilar in thickness to that of the steel tape found in tape measures, though could be constructed of much thinner material. 
         [0025]    Still referring to  FIG. 2 , upon impact the sliding outer body  12  would be urged backward releasing the blades  20  which, in the retracted state, are secured tightly around the grooves of the ferrule body  30  sufficient to be contained by the sliding outer body. The blades would preferably be constructed of flat stock whereby the natural state of this material would be flat and linear and would resist being coiled and once coiled would flatten if not restrained. In order to return to a retracted state, a blade guide  16  is disposed along the leading edge of the outer body  12 , in which a single blade may be aligned and wound by rotating the blade point  28 . This process would continue until all blades were wound and covered. 
         [0026]    It may be preferable that the sliding outer body  12  be rotatable relative to the device and that the ferrule body be fixed and non rotatable. In the later case, retracting the blades would be effected by sliding the outer cover forward engaging the rearmost blade then winding the cover until the secure blade disappears under the sliding blade cover. This operation would be continued until each blade is retracted. The sliding cover would then be secured by the clip  26  and recess latch. 
         [0027]    Referring to  FIG. 3 , a first alternate embodiment is shown using a more sweeping type fixed blades in which two retractable blades would be contained in an arrangement similar to that of the first embodiment.  FIG. 3  shows the sliding outer cover in the retracted state.  FIG. 4  shows the sliding outer cover in the deployed state. 
         [0028]    Referring to  FIG. 5  a second alternative embodiment, a spring loaded cockable broadhead  34  is shown. The blades  20  as with the previous embodiment are constructed of thin, flexible sheet type steel. In this figure the blades are in a retracted cocked state, wherein the point  28  is shown in an cocked position being extended slightly forward relative to the broadhead. 
         [0029]    Referring to  FIG. 6 , the spring powered cockable broadhead is shown in a deployed state while piercing into a target mass  29 . The point  28  is shown depressed after meeting sufficient resistance from the target mass  29  upon or just prior to penetration, whereupon the blades  20  are projected outward from a plurality of slots  36  found in a blade retention cover  41 . Blade slots  36  allow for the blades  20  to extend outwardly in a substantially transverse plane to that of the broadhead  34 . A screw connector  40  is shown, as typical with broadheads in general, provides a means for connecting the broadhead to the shaft of the arrow. 
         [0030]    Referring to  FIG. 7 , a view of the cockable broadhead is shown in which the blades and the retention cover are not included. The fixed axle  42  is shown and a spring/trigger housing  66  is shown just to the rear of the point  28 . 
         [0031]    Referring to  FIG. 8  an enlarged view of the axle  42  is shown along with a set screw  67  whereby the axle  42  may be secured to the shaft of the broadhead in a non rotatable state. 
         [0032]    Referring to  FIG. 9  The spring/trigger mechanism is shown in a wound and cocked position. The point  28  is shown extended outwardly in a windable/cocked position. The point  28  is fixedly disposed on a winding shaft  38  which in turn is rotatably disposed on the fixed axle  42 . Fixedly disposed on the winding shaft  38  is a ratchet assembly  54  comprising a ratchet gear  46  and a stop bar assembly  59 . The ratchet gear  46  is held to a clockwise/only moveable state by means of a stop bar  56  and a stop bar spring  65 . The point  28  is able to crank in a clockwise motion in which to wind a spring  45 . The spring  45  is held fixed to the rotatable hub with tab  44  and though not shown the spring  45  would be anchored to the fixed axle  42 . A winding assembly  48  comprises a generally bracket shaped assembly which meshes into the winding gear  52 . When the point  28  is extended outward, as with winding a watch, the winding assembly will mesh with the winding gear  52  with which to enable the tightening of the spring  47  causing the blades to retract into a cocked state. 
         [0033]      FIG. 10  shows an enlarged view of the stop bar assembly  59  in which a spring  60  secures a ratchet member  56  in a stable downward position relative to the stop bar  58 . The ratchet member  56  is hingeably disposed on a shaft  64  extending outward from a stop bar anchor  62 . 
         [0034]    Referring to  FIG. 11  a third alternate embodiment: a bale secured broadhead  69  of the present invention is shown. This embodiment is comprised of a plurality of blades  20  capable of being held arcuately wrapped to the shaft of the broadhead by means of a pair of bales  70 . The bales are pivotably disposed rear of the blades and when securing the blades  20  would be clipped by means of respective clips  72  disposed forward of the blades  20 . Though not shown the blades  20  are disposed as with previous type embodiment on the ferule body by means of set screws or other suitable fasteners. Still referring to  FIG. 11 , the blades  20  are shown in a retracted state. Though not shown, the ferule body of the bale secured broadhead would be pivotable disposed along a fixed axle ridgidly disposed within the screw base allowing for free revolution therealong. A hinge collar  76  and a clip collar  78  would be fixedly disposed along the fixed axle. 
         [0035]      FIG. 12  shows a perspective view of the bale secured blades in a deployed state. 
         [0036]      FIG. 13  shows the bale secured broadhead in a retracted state. 
         [0037]    Operation of the third alternate embodiment. 
         [0038]    In order to retract the blades  20  with the bale secured broadhead  69  the user would clip the bales in place and wind the point until the blades  20  are tightly wound along the shaft of the broadhead where the blades are respectively attached thereto. 
         [0039]    It should be noted that within the bow hunting/broadhead art these devices are typically screwable or otherwise affixable to the shaft of an arrow. The simplicity of the present invention&#39;s blade(s) would allow for the attachment of same to what is commonly known as a field point. In fact a channel could be recessed within the shaft of an aluminum or carbon fiber shaft for the expressed purpose of attaching these type blades directly onto the shaft further reducing the cost of production thereby. 
         [0040]    While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. This is especially true in light of technology and terms within the relevant art(s) that may be later developed. Thus, the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.