Auxiliary cutting implement for arrow

Abstract

An auxiliary cutting implement for attachment between a broadhead and arrow shaft includes preferably two or more coils each having two cutting edges formed along their opposite elongated side edges. As the coils pass through the animal they unroll and slice through animal flesh in all directions. The coils are biased toward their rolled position which increases the multi-directional movement of the coil and cutting edges through the animal resulting in a large cutting area and fast kill as compared to the broadhead alone.

Claims

1. An auxiliary cutting implement for use with an arrow and broadhead, said auxiliary cutting implement comprising: a) a central fitting having a central opening; and b) two or more elongated strips extending radially outwardly of said central fitting, each of said elongated strips having first and second opposite side edges formed as a cutting edge, each of said elongated strip further formed into a rolled coil, wherein said elongated strips are formed from a material having spring bias such that when said coils are unrolled, said strips are biased in a direction returning to their rolled condition.

2. The auxiliary cutting implement of claim 1 wherein said central fitting and said elongated strips are formed from the same piece of material.

3. The auxiliary cutting implement of claim 2 wherein said material is stainless steel sheet metal.

Description

DESCRIPTION OF THE DRAWING FIGURES

(1) The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become apparent and be better understood by reference to the following description of the invention in conjunction with the accompanying drawing, wherein:

(2) FIG. 1 is a perspective view of a prior art arrow;

(3) FIG. 2 is a perspective view of a prior art broadhead;

(4) FIG. 3 is a perspective view of a roll of sheet metal from which the auxiliary cutting implements may be made;

(5) FIG. 4 is a plan view of a three coil embodiment prior to formation of the strips into coils;

(6) FIG. 5 is a plan view of a four coil embodiment prior to formation of the strips into coils;

(7) FIG. 6 is a perspective view of an embodiment of a three coil auxiliary cutting implement;

(8) FIG. 7 is a perspective view of another embodiment of a three coil auxiliary cutting implement;

(9) FIG. 8 is a perspective view of a mechanical drawing of another embodiment of a three coil auxiliary cutting implement;

(10) FIG. 9 is a perspective view of an embodiment of a four coil auxiliary cutting implement;

(11) FIG. 10 is a perspective view of another embodiment of a four coil auxiliary cutting implement;

(12) FIG. 11 is a fragmented, perspective view of another embodiment of a four coil auxiliary cutting implement mounted to an arrow and prior to firing the arrow; and

(13) FIG. 12 is a fragmented, perspective view of an embodiment of the four coil auxiliary cutting implement following firing of the arrow to which it is mounted and removal from the stricken animal.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(14) Referring now to the drawing figures, there is seen in FIG. 1 a common prior art arrow 10 including an arrow shaft 12 having first and second ends 12a and 12b with an arrow nock 14 attached to first end 12a and an arrowhead in the form of a target point 16 attached to second end 12b. Fletchings 18 located adjacent nock 14 provide the aerodynamics allowing for a substantially straight flight path upon firing the arrow 10 from a bow (not shown). Arrows may have permanently mounted arrowheads or removable arrowheads which allow the archer to interchange arrowheads upon the arrow shaft as desired.

(15) FIG. 2 illustrates a typical broadhead type of arrowhead that is popular with hunters. The broadhead 20 shown in FIG. 2 is referred to as a mechanical broadhead in that the blades 22a, 22b thereof are movable from a closed position (not shown) to the open position shown. Blades 22a, 22b include respective elongated slots 22a′, 22b′ which are mounted on a common pin 24 allowing the blades to slide on the stationary pin and come to rest within respective longitudinal grooves 26a and 26b formed in the broadhead main body 26. The distal end of broadhead 20 includes a pointed tip 28 while the proximal end includes a threaded shank 30 allowing broadhead 20 to be removably mounted to the end of an arrow opposite the nock end. For example, in the arrow 10 of FIG. 1, the plain target point 16 may be removed from shaft 12 and replaced with broadhead 20 by threading threaded shank 30 into a threaded hole (not shown) provided at end 12b. The threaded hole may be formed directly into the shaft or it may be provided as a separate insert as is known to those familiar with archery and particularly bow hunting.

(16) As explained in the Summary of the Invention, designers of broadheads attempt to maximize the cutting capability of the broadhead blades without negatively impacting aerodynamic performance which has necessarily imposed limitations on the cutting area present day broadheads can provide. The present invention obviates these design limitations by providing an auxiliary cutting implement which is not part of the broadhead but rather is an attachment which is mounted between the arrow shaft and a detachable broadhead of any desired design (e.g., fixed blade, mechanical blade, double blade, triple blade, etc.).

(17) Referring to FIGS. 3-5, FIG. 3 shows an example of a roll of sheet metal 30 from which the invention may be formed (e.g., by cutting or stamping). The type of material chosen may vary as desired but it preferably a metal that will have a spring bias (shape memory) upon bending prior to reaching the fatigue point of the metal. In an embodiment, the material may be full hard stainless steel shim stock in a sheet thickness of about 0.007 to about 0.010 inches.

(18) A three coil auxiliary cutting implement may be cut from an unrolled segment 30a of material in the form seen in FIG. 4 which includes a central annular fitting 40 having a center hole 42 and three elongated, generally rectangular strips 44a, 44b and 44c extending radially therefrom in a substantially equally spaced manner thereabout.

(19) A four coil auxiliary cutting implement 51 may be cut from an unrolled segment 30a of material in the form seen in FIG. 5 which includes a central annular fitting 50 having a center hole 52 and four elongated, generally rectangular strips 54a, 54b, 54c and 54d extending radially from central fitting 50 in a substantially equally spaced manner thereabout.

(20) A three coil cutting implement is preferred for use with a three blade broadhead whereas a four coil cutting implement is preferred for use with a two blade broadhead. As such, the coils may be positioned in a location which aligns with the spaces between the blades to create symmetry which aids in aerodynamically balancing the arrow (see FIG. 11 where two coils 54a′ and 54b′ are located in between blades 22a and 22b while the other two coils are located on the opposite side and again in between blades 22a and 22b). While a maximum of six coils is preferred, it is possible to further increase the number of coils beyond six if desired.

(21) It may thus be realized that the auxiliary cutting implement may be formed as a unitary part where the central fitting and elongated strips are cut or otherwise formed into a single piece of material. Each elongated strip 54a, 54b, 54c and 54d includes respective first and second opposite elongated side edges 51a,51b, 53a,53b, 55a,55b and 57a,57b. These side edges form the cutting edges and there are thus two cutting edges per strip/coil. This contrasts with a broadhead which provides only a single cutting edge per blade. The side cutting edges may be formed in any desired blade cutting edge and point style such as straight, serrated and tanto, for example. The side cutting edges may be formed at the initial cutting of material segment 30a or may be performed in a subsequent operation.

(22) The strips are then preferably bent away from the plane P (seen best in FIG. 8) of the central fitting 40 and 50 at the point where the strips extend from the central fitting 40 and 50 (e.g., using a mandrel), and are formed into individual coils (e.g., using a sheet metal curling tool such as a step brake press) as seen in FIGS. 6-8 (three coils 44a′, 44b′ and 44c′) and FIGS. 9-11 (four coils 54a′, 54b′, 54c′ and 54d′). Using the four coil embodiment to illustrate, auxiliary cutting implement 51 may be mounted between an arrow shaft 12 and broadhead 20 by passing threaded shank 30 through central fitting hole 52 and threading threaded shank 30 into the threaded hole (not shown) provided at arrow end 12b. The arrow may then be fired with the coils imparting no adverse effects on the arrow aerodynamics.

(23) Once the broadhead 20 penetrates the animal, the coils 54a′, 54b′, 54c′ and 54d′, which trail behind the broadhead blades 22a and 22b, unroll as they encounter the force imparted by skin, flesh and organs. As the coils unroll, the cutting edges formed on either edge of the coil strips (two per coil) slices through the animal. Since the coils have shape memory they are biased toward the rolled coil position seen in FIGS. 9-11 such that they transition from this initial rolled coil position toward a fully unrolled position and bias back toward the coil position. FIG. 12 illustrates an actual four coil auxiliary cutting implement after removal from the animal. It can be seen the coils have unfurled and are between the rolled coil conditions seen in FIGS. 9-11 and the fully unrolled conditions seen in FIG. 5. As the coil transitions from the rolled coil condition as it travels through the animal, the cutting edges 51a,51b, 53a,53b, 55a,55b and 57a,57b of the coils (there are a total of eight cutting edges in the four coil embodiment) slice through the flesh in all directions producing a cutting area which is significantly greater than that produced by the broadhead blades themselves.

(24) While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as described.