Unitary broadhead blade unit
A unitary blade unit for an archery broadhead includes a tip structure and blades inseparably connected into a single blade unit. The blade unit is made by molding such as metal injection molding or laser welding.
This application claims priority to, is a continuation of, and incorporates by reference U.S. Patent Application. No. 10/185,089, filed Jun. 28, 2002, which in turn claims priority to: (1) U.S. Provisional Patent Application No. 60/354,214, filed Feb. 4, 2002; (2) U.S. Provisional Patent Application No. 60/365,249, filed Mar. 18, 2002; (3) U.S. Pat. No. 6,726,581, filed Aug. 4, 2001 (continuation-in-part), which claimed priority to U.S. Provisional Patent Application No. 60/265,114, filed Jan. 31, 2001, and U.S. Provisional Patent Application No. 60/293,307, filed May 24, 2001; and (4) U.S. Pat. No. 6,605,012, filed Mar. 8, 2002 (continuation-in-part), which claimed priority to U.S. Provisional Patent Application No. 60/273,819, filed Mar. 8, 2001, and U.S. Provisional Patent Application No. 60/286,030, filed Apr. 24, 2001.
FIELD OF THE INVENTIONThe present invention generally relates to archery equipment. More particularly, the present invention relates to a unitary broadhead blade unit for hunting arrows, along with a method for manufacturing a unitary blade unit for a modular broadhead.
BACKGROUND OF THE INVENTIONTraditionally, archery broadheads are made from multiple pieces that are fitted together. The pieces may include individual blades, a tip, and/or other connecting parts. Traditional broadheads also include a means for connecting the broadhead to an arrow, such as a receptacle designed to fit over the shaft of an arrow, with threads or glue to secure the broadhead to an arrow. However, such broadheads can be expensive to manufacture, and they can become loose, and may even separate, through use or transport.
One attempt to overcome this problem is described in U.S. Pat. No. 6,290,903, to Grace, Jr. As described in
Accordingly, it is desirable to provide an improved unitary blade unit for a modular broadhead.
SUMMARY OF THE INVENTIONIn accordance with one embodiment of the invention, a method of manufacturing a unitary blade unit for a modular broadhead includes providing (i.e., using) a mold having one or more cavities that define a multiple-bladed blade unit. A mixture of metal and binder is inserted into the mold, and the mixture is compacted in the mold to form an intermediate blade unit. The intermediate blade unit is processed to remove at least a portion of the binder and sintered to form a sintered blade unit. The blades of the sintered blade unite are sharpened to form a cutting edge on each blade to yield a final blade unit. The final blade unit requires a separate ferrule in order to attach to an arrow. In certain embodiments, the mixture is in powdered form, and the sintering step may include sintering at an elevated temperature and pressure.
In accordance with another embodiment, a method of manufacturing a blade unit for a modular broadhead includes using metal injection molding to form a blade unit from a mixture that includes metal and a binder. The blade unit has at least two blades and requires a separate ferrule in order to attach to an arrow. In embodiments, the method may also include manufacturing a separate adapter for securing the blade unit to the ferrule. Further, the method may include forming the blade unit to include a first integral adapter for securing the blade unit to the ferrule, as well as manufacturing a second separate adapter for further securing the blade unit to the ferrule.
In accordance with an alternate embodiment, a method of manufacturing a blade unit for a modular broadhead includes arranging multiple components in the form of a blade unit for a modular broadhead. An energy beam is directed toward contact segments (i.e., locations where at least two components are in contact) to weld the components into a blade unit. The components may include blades, a cap structure for receiving a separable ferrule, and/or a collar for receiving a separable ferrule. In embodiments, the energy beam may be a laser, and the method may include focusing the energy beam toward a contact segment using one or more devices such as a focus cell, a lens, and/or a mirror. A focal point of the energy beam may be moved along a contact segment in a direction from a tip of the blade unit to a base of the blade unit.
BRIEF DESCRIPTION OF THE DRAWINGS
In the embodiment illustrated in
Returning to
In the preferred embodiment shown in
The base collar 20 such as that illustrated in
Returning to
In the preferred embodiment of
The frontal point 18 of the blade unit is the first part that will contact a target. Since it is just a point, and since it will receive a tremendous force upon impact, it is preferred that the blade unit be constructed in such a way that it has additional strength. This can be accomplished by tapered grinding, moving over a sharpening stone, or other sharpening of the razor edges 12. With such a procedure, each razor edge 12 may be sharpened at an angle that is greater than the angle that the razor edge 12 is adjacent to the base 14 of the blade 16. Near the frontal point 18, the angle is preferably less sharp, this providing a wider cutting edge near the frontal point 18 than near the base 14.
The unitary blade unit is preferably made of any metal. More preferably, the unitary blade unit is made using carbon steel, stainless steel, spring steel, tool steel, or titanium, or a composition including any of the above.
In a preferred method of manufacturing the unit using metal injection molding, the steps shown in
Alternatively, the blade unit may be made by assembling the blades into a unitary structure. Preferably, with this method the blades will be fastened together using any commonly known welding procedure such as laser welding, electron beam welding, TIG welding, plasma welding, resistance welding, electron beam welding, fusion welding, pressure welding, friction welding, ultrasonic welding, or other welding methods. Preferably, when manufacturing the unit by welding, the weld of each seam is begun at or near the frontal point and proceeds toward the base. Alternatively, fastening methods other than welding may be used. Exemplary laser welding equipment and procedures are illustrated in
The unitary blade unit provides several advantages over the prior art. For example, by providing a separate blade unit and ferrule, a user can replace only one part (i.e., either the blade or the ferrule) without replacing the other, thus reducing replacement costs. In addition, the separation of blade and ferrule allows the manufacturer to provide a weight-adaptable broadhead by manufacturing a standard blade unit and varying ferrules having different weights. In addition, the blade unit and the ferrule may be made of different materials. Thus, the weight of the overall broadhead (i.e., the combination of the blade and ferrule) optionally may be varied by changing the ferrule without replacing the blades, or vice versa. Further, although the blade-unit can be sharpened by grinding, polishing, sanding, or any standard sharpening method, the user may decide to simply dispose of the unitary blade unit and attach a new blade unit to an existing ferrule, resulting in ease of use for the user and the potential for increased sales for the manufacturer.
When made by metal injection molding, the blade unit designer receives a tremendous amount of freedom in the shaping and designing of the unit. Exact radii, tapering, and other intricacies can be achieved with minimal cost difference. Metal injection molding also allows metal parts to have a complex geometry with great strength.
The many features and advantages of the invention are apparent from the detailed specification. Thus, the invention is intended to include all such features and advantages of the invention which fall within the true spirits and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described in the specification, claims, and drawings herein. Accordingly, all appropriate modifications and equivalents may be included within the scope of the invention.
Claims
1. A method of manufacturing a unitary blade unit for a modular broadhead, comprising:
- providing a mold having one or more cavities that define a multiple-bladed blade unit;
- inserting a mixture of metal and binder into the mold;
- compacting the mixture in the mold to form an intermediate blade unit;
- processing the intermediate blade unit to remove at least a portion of the binder;
- sintering the intermediate blade unit to form a sintered blade unit; and
- sharpening the blades to form a cutting edge on each blade to yield a final blade unit, wherein the final blade unit requires a separate ferrule in order to attach to an arrow.
2. The method of claim 1 wherein the mixture is in powdered form.
3. The method of claim 1 wherein the sintering step comprises sintering at an elevated temperature and pressure.
4. A method of manufacturing a blade unit for a modular broadhead, comprising using metal injection molding to form a blade unit from a mixture that includes metal and a binder, wherein the blade unit has at least two blades and requires a separate ferrule in order to attach to an arrow.
5. The method of claim 4 further comprising manufacturing a separate adapter for securing the blade unit to the ferrule.
6. The method of claim 4 wherein the method includes forming the blade unit to include a first integral adapter for securing the blade unit to the ferrule.
7. The method of claim 4 wherein the method further includes manufacturing a second separate adapter for further securing the blade unit to the ferrule.
8. A method of manufacturing a blade unit for a modular broadhead, the method comprising:
- arranging a plurality of components in the form of a blade unit for a modular broadhead; and
- directing an energy beam toward a plurality of contact segments to weld the plurality of components into a blade unit, wherein each contact segment comprises a location where at least two of the plurality of components are in contact.
9. The method of claim 8 wherein the plurality of components comprises a plurality of blades.
10. The method of claim 9 wherein the plurality of components further comprises a cap structure for receiving a separable ferrule.
11. The method of claim 9 wherein the plurality of components further comprises a collar structure for receiving a separable ferrule.
12. The method of claim 9 wherein the plurality of components further comprises a tip structure.
13. The method of claim 8 wherein the energy beam is a laser.
14. The method of claim 8 wherein directing an energy beam comprises performing laser welding.
15. The method of claim 8 wherein directing an energy beam comprises focusing the energy beam toward a contact segment using a device.
16. The method of claim 8 wherein the device comprises one or more of a focus cell, a lens, and a mirror.
17. The method of claim 8 wherein directing an energy beam comprises moving a focal point of the energy beam along a contact segment in a direction from a tip of the blade unit to a base of the blade unit.
18. The method of claim 8 wherein a plurality of energy beams are directed toward a plurality of contact segments simultaneously, wherein each energy beam is directed toward a particular contact segment.
Type: Application
Filed: Apr 11, 2005
Publication Date: Aug 18, 2005
Inventor: Philip Muller (Mercerville, NJ)
Application Number: 11/102,939