Broadhead With Deployable Cutting Blades

The foregoing and other objects, aspects and advantages of the invention will be better understood from the following detailed description of the preferred embodiments of the invention with reference to the accompanying drawings, in which:

FIG. 1 is an isometric view of a broadhead with fully retracted blades and reflects the "in flight" configuration of the broadhead;

FIG. 2 is an isometric view of the broadhead shown in FIG. 1 with fully opened blades and reflects the "impact" configuration of the broadhead;

FIG. 3 is a cross-sectional side view of a broadhead in the in flight configuration showing one upper blade in its fully retracted position;

FIG. 4 is a cross-sectional side view of the broadhead shown in FIG. 3 taken 90.degree. therefrom showing one lower blade in its fully retracted position;

FIG. 5 is a cross-sectional side view of a broadhead in the impact configuration showing the upper pair of blades in their open position;

FIG. 6 is a cross-sectional side view of the broadhead shown in FIG. 5 taken 90.degree. therefrom showing the lower pair of blades in their open position;

FIG. 7 is a cross-sectional side view of a plunger tip showing the pin position of the upper pair of blades;

FIG. 8 is a cross-sectional side view of the plunger tip shown in FIG. 7 taken 90.degree. therefrom showing the pin position of the lower pair of blades;

FIG. 9 is a plan view of a C-shaped ring used to lock the plunger in position;

FIG. 10 is a side view of the C-shaped ring shown in FIG. 9;

FIG. 11 is a cross-sectional side view of a broadhead in the impact configuration showing the upper pair of blades pivoted forward from their open position;

FIG. 12 is a cross-sectional side view of the broadhead shown in FIG. 11 taken 90.degree. therefrom showing the lower pair of blades pivoted forward from their open position;

FIG. 13 is an enlarged cross-sectional side view of the plunger and cap of the broadhead shown in FIGS. 3 and 4; and

FIG. 14 is an enlarged cross-sectional side view of an alternative plunger and cap for the broadhead shown in FIG. 13.

Referring now to the drawings, and more particularly to FIGS. 1 and 2, there is shown a broadhead 10 in its "in flight" and "impact" configurations, respectively, having a pointed plunger tip 12, a cylindrical body 14, and a threaded bottom 16. The broadhead 10 is secured to an arrow shaft (not shown) by threaded bottom 16. Shoulder 18 fits within a counterbore in the top of the arrow shaft. The cylindrical body 14 has slots 20 and 22 which house upper and lower pairs of cutting blades 24 and 26, respectively. Preferably, the slots 20 and 22 are positioned such that the blades 24 and 26 extend at each 90.degree. increment around the cylindrical body 14.

In operation, the plunger tip 12 is fully extended as shown in FIG. 1 when the broadhead is in flight. As described below, the cutting blades 24 and 26 are secured to the plunger 12 on pivot pins so that when the plunger tip 12 moves towards the cylindrical body 14, the cutting blades 24 and 26 are cammed open to the impact configuration shown in FIG. 2 when an animal is struck by the arrow. A tubular restraint 11 which encircles the body 14 can be used to hold the blades 26 within the body during the flight of the arrow. The tubular restraint 11 is preferably made of a plastic, vinyl, rubber, cardboard, or other cuttable material, and is installed on the broadhead 10 over the slots 22 when the broadhead is in the in flight configuration of FIG. 1. The tubular restraint 11 should be strong enough to withstand forces which tend to force the cutting blades 26 outward when the arrow is shot, i.e., due to inertia, the plunger 12 will tend to remain stationary when the arrow is shot, but the cylindrical body 14 will be urged forward with the arrow shaft. Hence, the tubular restraint 11 must be strong enough not to be cut upon shooting the arrow and will keep the plunger 12 forward in flight. However, the tubular restraint 11 must be weak enough to be cut when the plunger 12 impacts against an animal so that the blades 24 and 26 can be forced outwardly to cause maximum hemorrhaging. A C-shaped ring (not shown), housed within cap 28 locks the blades 24 and 26 in their open configuration when it fits into the channel 30 encircling the plunger tip 12 towards its top section. In addition, as will be described below, the C-shaped ring can be used as an alternative means to the tubular restraint 11 for keeping the plunger 12 and cutting blades 24 and 26 in their in flight configuration.

Referring now to FIGS. 7 and 8 in addition to FIGS. 3 and 4, the upper blades 24 fit within slot 50 and are connected to the plunger 12 by pivot pin 32 and the lower blades 26 fit in slot 51 at the base of the plunger 12 and are connected to the plunger by pivot pin 34. Preferably, a frictional engagement exists between the plunger 12 at slots 50 and 51 and the blades 24 and 26 which will aid in holding the blades 24 and 26 in the body 14 during the flight of the arrow. The frictional engagement can be provided by adding a bent washer, belleville washer, lock washer or some other additional element on the pivot pin between the pairs of blades 24 and 26 within the slots 50 and 51 as described in the co-pending application having Ser. No. 07/460,299 or by sizing the width of the slots 50 and 51 so that the pairs of blades 24 or 26 fit snugly within their respective slots or appropriately deforming the blades or by some other suitable mechanism.

Referring now to FIGS. 3, 4, 7, 8, 9, and 10, the C-shaped ring 48 positioned within the space between the cap 28 and the cylindrical body 14 has a smaller diameter than the plunger tip 12; therefore, the force of the impact must open the C-shaped ring slightly so that it may ride against the plunger tip 12 as it slides into the cylindrical body 14 and then snap into the channel 30 to lock the blades 24 and 26 open. The C-shaped ring 48 holds the plunger tip 14 in its fully extended position shown in FIGS. 3 and 4 by resting within a shallow, rear channel 56. Since the plunger tip 12 is larger in diameter than the C-shaped ring 48, the plunger tip 12 is prevented from moving during flight. An alternative method for holding the plunger tip 12 in its extended position is to have a plunger tip 12 fabricated which increases in diameter towards the front of the plunger tip 12. In the alternative method, the outwardly tapered sidewall of the plunger tip 12 would provide a functionally similar result as the shallow, rear channel 56. Upon impact with the animal, the C-shaped ring 48 is deformed by enlarging at gap area 58 so that it may ride against the outside wall of the plunger tip 12. The C-shaped ring 48 snaps into the front channel 30 to lock the blades 24 and 26 in the "impact" position so that a deer may not pull the broadhead 10 out of its body. It is also anticipated that other types of rings such as 0-rings, etc. could fulfill the function of C-shaped ring 48 and would perform as described above.

Referring now to FIGS. 5, 6, 11, and 12, which show cross-sectional views taken at 90.degree. increments with respect to one another of a broadhead 10 in its "impact" configuration in FIGS. 5 and 6 and in its "non-barbed" configuration shown in FIGS. 11 and 12, the upper blades 24 are cammed open on surface 38 and the bottom blades 26 are cammed open against the pin 44 when the plunger 12 is forced into the cylindrical body 14. The C-shaped ring 48 positively locks the blades 24 and 26 in their open positions so that the animal will have maximum hemorrhaging. To comply with gaming laws in some states, the blades 24 and 26 are able to pivot forward within the slots 20 and 22 on pivot pins 32 and 34, respectively, to a non-barbed configuration.

Referring now to FIGS. 13 and 14 which show the manner in which the cylindrical body 14 fits together with the cap 28. A threaded section 60 at the end of the body 14 mates with a threaded section inside the cap 28. With reference back to FIGS. 1 and 2, the threaded section 60 is split four ways for slots 20 and 22. FIG. 13 shows that the base of the cap 28 meets flush with a flat shoulder 62 of the cylindrical body 14. While the arrangement shown in FIG. 13 does work properly, there is a tendency, if the cap 28 is screwed down too tightly, for the cylindrical body 14 to be forced inward such that it frictionally hinders the plunger 12 from sliding freely into the body 14. It has been discovered that a bevelled shoulder 64 on the cylindrical body 14 and a corresponding bevelled base 66 on the cap 66 provides a lifting function as the cap 28 is screwed tight which avoids having the cylindrical body 14 squeezed inwardly against the plunger 12.

While the invention has been described in terms of its preferred embodiment where two pairs of cutting blades are positioned on pivot pins connected to a front plunger tip at different heights and are spaced at 90.degree. increments about the cylindrical body, those skilled in the art will recognize that the number of blades and their placement relative to the cylindrical body can be varied within the spirit and scope of the appended claims.