PRODUCTS AND PROCESSES FOR MAKING BROADHEADS OF AMORPHOUS ALLOYS

Embodiments of the present disclosure include broadhead assemblies and components for use with an archery bow and arrow. Embodiments of the present disclosure include products and methods of making broadhead assemblies and components using bulk solidifying amorphous alloys.

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Description

This application claims priority to provisional application Ser. No. 62/048,839 filed on Sep. 11, 2014, which is incorporated herein by reference.

FIELD OF THE INVENTION

This disclosure relates broadly to broadheads for arrows and more particularly to broadheads made from amorphous alloys and methods of manufacturing such broadheads.

BACKGROUND OF THE INVENTION

In archery, an arrow is normally equipped with a point or head that engages a target. In bowhunting, broadheads may be used to increase damage to or bleeding of the target and otherwise facilitate capture of the target. Some broadheads have two or more fixed blades which radially extend from a center core portion or ferrule. Example embodiments include two, three, four or more blades. In some embodiments, the blades are removably mounted to the ferrule to assemble the broadhead, in alternate embodiments it is desirable to have a unitary broadhead where the blades and ferrule are formed as a single piece. Alternately, mechanical broadheads have two or more movable blades which are retracted during flight and which deploy upon impact with a target.

In traditional broadheads, the blades are made of sharpened steel, which can be expensive to manufacture. The blades may become dull and may need to be sharpened or replaced after successive uses. Further, the blades may be damaged by use, can rust due to exposure during use or storage or can break if bent or twisted incorrectly.

SUMMARY OF THE INVENTION

Embodiments of the present disclosure include fixed and mechanical broadhead assemblies and components for use with an archery bow and arrow. Embodiments of the present disclosure include products and methods of making broadhead assemblies and components using bulk solidifying amorphous alloys.

In one embodiment, a method of making a broadhead assembly including providing a reusable mold defining an internal mold cavity matching the shape geometry of a broadhead assembly with a ferrule and a plurality of integrated blades with edges, wherein the mold cavity profile net-to-shape size is less than 0.5% larger that the profile of the intended finished broadhead assembly. Typically, the mold defines a passageway to deliver liquid metal from an entry site to the mold cavity. A feedstock of metal is heated to a liquid non-crystalline state and then injected into the mold cavity via the passageway to fill the mold cavity. The liquid-state metal is rapidly cooled to an amorphous non-crystalline solid state. The mold is then opened and the finished broadhead assembly is ejected. The blade edges can then be sharpened to a desired cutting radius in a finishing step.

In an alternate embodiment, a method of making a broadhead component includes providing a reusable mold defining an internal mold cavity matching the shape geometry of a broadhead component, wherein the mold cavity profile net-to-shape size less than 0.5% larger that the profile of the intended finished broadhead component. The mold typically defines a passageway to deliver liquid metal from an entry site to the mold cavity. A feedstock of metal is heated to a liquid non-crystalline state, and then injected into the mold cavity via the passageway to fill the mold cavity. The metal is then rapidly cooled to an amorphous non-crystalline solid state. The mold is then opened and the finished broadhead component is ejected.

Certain embodiments of the present disclosure include unitary or monolithic broadhead assemblies as well as components made from amorphous alloys. Example components are broadhead ferrules or broadhead blades. Components made individually can be assembled into broadhead assemblies with other components made from amorphous alloys or with other components made from other materials.

Other objects and attendant advantages will be readily appreciated as the same become better understood by references to the following detailed description when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a broadhead with three fixed blades.

FIG. 2 is a perspective view of an alternate fixed blade broadhead.

FIG. 3 is a perspective view of a further embodiment of a fixed blade broadhead.

FIG. 4 is a perspective view of a broadhead embodiment with two fixed blades.

FIG. 5 is a perspective exploded view of a body and blades which can be assembled to form a fixed bladed broadhead.

FIG. 6 is a perspective exploded view of an embodiment with blades which can be assembled to form a mechanical broadhead.

FIG. 7 is a perspective exploded view of an alternate embodiment with a piston assembly and blades which can be assembled to form a mechanical broadhead.

FIG. 8 is a perspective view of a ferrule piece which can be used in certain broadhead embodiments.

FIG. 9 is a perspective view of an alternate ferrule piece which can be used in certain broadhead embodiments.

FIG. 10 illustrates a diagram of a process for manufacturing archery broadhead assemblies or components.

FIG. 11 is a rear view of the embodiment of FIG. 1 illustrating example part line locations for a three piece mold to make the illustrated embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations, modifications, and further applications of the principles being contemplated as would normally occur to one skilled in the art to which the invention relates

FIG. 1 shows a representative embodiment of a broadhead or broadhead assembly generally designated 10. As intended for all of the embodiments disclosed herein, the broadhead 10 is adapted for mounting to an open end of a hollow arrow shaft 14. To be used with an archery bow. Preferably, rearward end 24 includes threads configured for pairing with threads 16 inside of the arrow shaft. In other forms, broadhead 10 may be mounted to an arrow shaft in other ways, such as with mechanical fasteners, adhesives, resins, an arrow shaft insert/adaptor, or using other attachment techniques.

Arrows equipped with broadheads such as broadhead 10 can be used, for example with archery bows for hunting. Typically, a bow includes a riser with a handle and an arrow rest, an upper limb portion and a lower limb portion. A bowstring extends between the limbs and may be secured to the limb tips or may be arranged as a compound bow, with related cables, on a cam or pulley system. From the perspective of the archer, the bowstring is considered rearward relative to the riser which defines forward. Directional references herein are not intended to be limiting.

When the bowstring is drawn it bends the limb portions inward, causing energy to be stored therein. When the bowstring is released with an arrow engaged to the bowstring, the limb portions return to their rest position and take up the bowstring which launches the arrow with an amount of energy proportional to the energy stored in the bow limbs. The present invention can be used with compound bows, recurve bows, crossbows or other types of bows, which are considered conventional for purposes of the present invention.

As used herein, a broadhead assembly includes a body and blades, wherein the blades may be fixed relative to the body during use, which includes blades which are integrally formed with the body as one piece, blades which are permanently mounted to the body and blades which may be selectively assembled and secured on the body to be fixed in place. The term broadhead assembly also includes mechanical broadheads where one or more blades may move with respect to the body during deployment, such as by sliding or rotating. The broadhead assemblies herein typically have a mass size referred to as 100 grain or 125 grain, but alternately other sizes can be made.

The broadhead assembly 10 illustrated in FIG. 1 includes body 20 and three fixed blades 40. Body 20 has a forward end with a pointed tip 22, and a rearward end 24 configured to be connected to arrow shaft 14. Threaded rearward portion 24 transitions into a solid cylindrical portion 26 which ends at a forward shoulder 28, where shoulder 28 is slightly rearward of blades 40. Shoulder 28 abuts the forward facing surface of arrow shaft 14 when assembled. Alternately, an adaptor, washer or o-ring can be used between the broadhead and/or shoulder 28 and the arrow shaft.

The forward end of broadhead body 20 includes tip 22. The tip 22 may be made integrally with or separately and attached to a forward portion of the body. Typically, the pointed tip 22 is tapered rearwardly and outwardly. Separately mounted tips, for example, can be blade, chisel or trocar shaped. The tip base may extend outward from or may merge with the profile of blades 40.

A mid-portion of body 20 defines a ferrule portion 30. Ferrule portion 30 is illustrated with a generally circular cross-section along its length, although alternately other geometries may be used. The cross-sectional area may vary along the length of the ferrule portion 30. For example, the illustrated ferrule portion has a somewhat hourglass shaped profile, with a thinner middle section and larger diameter/thicker areas adjacent the tip 22 and adjacent shoulder 28. The thicker portions correspond in placement to the front and rearward portions of blades 40.

In certain embodiments, optional cavities such as dimples 32, 34 are defined in the ferrule portion. Dimples 32 and 34 reduce the mass of the broadhead. Dimples 32 and 34 define a smaller local cross-sectional area which is advantageous during cooling of the material during manufacturing. Dimples 32 and 34 may also create air gaps to enhance penetration during use.

Blades 40 extend radially outward from ferrule portion 30. In the illustrated embodiment, three equally spaced planar blades 40 extend from ferrule portion 30. The blades are spaced at approximately 120 degree intervals around the circumference of the ferrule portion. Other embodiments may include two, four or more blades, normally at equally spaced intervals. Blades 40 each include a sharpened cutting edge 42, optionally with a forward end which merges into tip 22. An inner edge 46 of each blade is connected to ferrule portion 30, and each blade has a trailing edge 48. In certain embodiments, blades 40 are formed integrally as one piece with body 20 such that inner edges 46 transition into ferrule portion 30 as a fused or monolithic structure. Alternately, blades 40 may be separate pieces which are mounted and secured to ferrule portion 30, for example with inner edges 46 received in corresponding slots or grooves defined in ferrule portion 30.

Embodiments of the present disclosure include broadheads and methods of making broadheads using bulk solidifying amorphous alloys, sometimes referred to as bulk metallic glass (BMG) materials. Brands of such materials include LIQUIDMETAL® and VITRELOY™ alloys. Conventional metals have an atomic structure that is referred to as crystalline, meaning they have a repeating structure formed in a crystal lattice array or pattern. The crystalline lattice array orders the atoms in spaced arrangements, which creates free volume areas and the materials may be subject to regional weaknesses due to grain boundaries and slip planes. In contrast, amorphous alloys are formed with a non-patterned atomic structure.

Amorphous alloys are formed by cooling a molten metal material quickly into a “glassy state,” before the atoms or molecules can settle into an orderly arrangement. Different from a crystalline structure, atoms in an amorphous structure are randomly arranged and the atomic structure contains no discernible pattern. Correspondingly, the atoms are packed more closely together with a lower free volume between them than would occur in a crystalline lattice array. As such, strength, hardness, elastic, wear resistance and other properties superior to the limits of conventional metals can be achieved because there is reduced free space within which the atoms can move and no grains or slip planes to cause regional weaknesses. For example, amorphous alloys may have strength-to-weight ratios typically twice that of titanium, magnesium or aluminum, can have a hardness typically twice that of steel and titanium and may allow for up to two percent elastic deformation before breaking or being permanently deformed.

A significant advantage of using amorphous alloys in an injection or casting process is that because the atoms are tightly spaced, there is virtually zero shrinkage during cooling, so the mold can effectively be made to a net-to-final-shape size. The expected shrinkage rate while cooling is less than 0.2%, which can be compared to an expected shrinkage rage of more than 0.6% for metal die cast components and plastic injection molded components. This compares even more favorably to metal injection molding (MIM) processes where the sintering step can cause shrinkage of 15-20% from a “green state.”

In certain preferred embodiments, the amorphous alloy used contains greater than 50% zirconium, for example with which can be described with the formula (Zr, Ti)a (Ni, Cu, Fe)b (Be, Al, Si, B)c, where a is in the range from about 30 to 74, b is in the range from about 5 to 60 and c is in the range from about 0 to 50 in atomic weight. One specific example formula is Zr67Cu10.6Ni9.8Ti8.8Be3.8 (wt %). Alternately, the alloy may be based on a ferrous material (Fe, Ni, Co).

Embodiments of the present disclosure include unitary or monolithic broadhead assemblies as well as components made from amorphous alloys. Aspects also include processes for making broadhead assemblies and components. Example processes include a form of injection molding where the amorphous alloy is heated to a molten state, for example an ingot is heated in a feed mechanism, and then injected under pressure into a mold. The mold cavity defines a unitary broadhead assembly or a specific desired component.

A measured amount of the molten alloy flows, for example due to an impelling force such as applied via a nozzle or a plunger, through an injection path or sleeve from the feed mechanism into the mold cavity and completely fills the mold cavity. Optionally, the mold cavity may be initially held in a negative pressure or vacuum state to assist in drawing the material fully into the mold cavity and to fully “pack” the material into all volumes of the mold cavity. After the mold is fully filled, a controlled cooling or quenching process begins which cools the alloy at a rate to ensure that the alloy forms an amorphous alloy rather than a crystal structure. When the material is sufficiently cool, the vacuum is released and mold can be opened. The finished piece is then ejected from the mold. After ejection, finishing steps can be performed separately, such as removing sprues, polishing and/or sharpening blade cutting edges.

FIGS. 1-9 show different embodiments of broadheads and components which can be made according to aspects of the present disclosure. In certain embodiments, the fixed broadheads can be made with three blades, as shown in embodiments 10, 10′ and 10″ in FIGS. 1-3 or in a two fixed blade version 110 as illustrated in FIG. 4. The two blade version 110 is configured to be mounted to an arrow shaft with an adapter. When made as integral assemblies, the front blade portions merge with and help form the tip and also merge with the front portion of the central ferrule portion. Similarly, a rear portion of each blade merges with the ferrule portion.

Optionally, each blade may define a central cut-out portion 44. The cut-out portion forms an opening which reduces the mass of the blade and correspondingly the assembly mass. Openings also enhance aerodynamics of the broadhead during use, for example by minimizing wind planning. In certain optional embodiments, such as broadhead 10″ illustrated in FIG. 3, the blade may define cross-members or struts which extend across the cut-out portion and which may sub-divide it into smaller openings.

In alternate embodiments, aspects of the present disclosure can be used to form separate components such as ferrules or blades which can be combined to form a broadhead assembly. For example, FIG. 5 illustrates an exploded view of parts of a broadhead assembly 210, portions of which can be made according to the present disclosure. Broadhead assembly 210 includes a ferrule portion 230. As illustrated, three blades 240 can be arranged with their inner edges to be received in corresponding slots or grooves in ferrule portion 230. A forward tip portion 222 can be securely mounted to the front of ferrule portion 230. Tip portion 222 has a base which extends more broadly than the forward tips of blades 240. When in place, tip portion 222 covers and secures the forward tips of blades 240 in place. The rearward portions of the inner edges of blades 240 are also secured to ferrule portion 230, for example with a saucer shaped washer or ring which is held in place, for example via friction, via an o-ring or by being sandwiched between the shoulder of the ferrule portion and an arrow shaft.

FIG. 6 illustrates an example of a mechanical broadhead assembly 310, portions of which can be made according to the present disclosure. Broadhead assembly 310 includes a ferrule portion 330. As illustrated, three blades 340 can be pivotally mounted with one end arranged in corresponding slots or grooves in ferrule portion 330. Blades 340 are typically pivoted forward of their pivot points to a configuration substantially parallel to the ferrule portion for storage and during flight of an arrow. Upon impact, the target preferably impacts a forward portion of each blade 340, causing the forward portions of the blades to rotate away from the ferrule portion to a deployed position.

FIG. 7 illustrates an example of a different mechanical broadhead assembly 410, portions of which can be made according to the present disclosure. Broadhead assembly 410 includes a housing 420 attachable to an arrow shaft. Housing 420 defines an internal bore. A ferrule portion 430 includes a forward tip and a rearward sliding shaft portion. The sliding shaft portion is arranged to be slidably mounted in the bore of housing 420. As illustrated, two blades 440, or alternately three blades, can be pivotally mounted with one end arranged in corresponding slots or grooves in ferrule portion 430. Ferrule 430 projects from housing 420 and blades 440 are typically pivoted rearward of their pivot points to a configuration substantially parallel to housing 420 for storage and during flight of an arrow. Upon impact, the target preferably impacts the tip and drives ferrule portion 430 rearward and into housing 420. Housing 420 applies a camming action to the inner edges of blades 440, causing the rearward portions of the blades to rotate away from the ferrule portion to a deployed position.

FIGS. 8 and 9 illustrate broadhead body pieces 520 and 620 which can used with two blades and three blades respectively. Bodies 520 and 620 each define a shaft portion 530 and 630. The forward end the shaft portion defines a tip 522 and 622, and the rearward end 524 and 624 is configured to be attached to an arrow shaft, typically with a threaded connection. In these embodiments, a hub assembly (not shown) may be slidably mounted on the shaft portion with two or three cutting blades, respectively, pivotally attached to a hub. Optionally, the blades abut a rearward shelf 528 and 628 on the body, which assists to maintain the blades in a closed position prior to impact. Upon impact, the target surface impacts the hub assembly, which causes the blades to disengage from the rearward shelf. As the broadhead continues to travel forward, the hub assembly moves rearward relative to the shaft portion. The blades slide along camming surfaces on the shelves so that the blades simultaneously pivot to rotate outward and translate rearward to a deployed position.

FIG. 10 illustrates an example process for molding broadheads and/or components using amorphous metal alloys. An initial step 702 involves defining a shape geometry for an archery broadhead assembly or component. Then, the shape geometry is used to determine the location for at least one parting line for at least one of a pattern, die or mold 704. In a clam-shell type mold, typically there are two parting lines. Additional parting lines may be present if a multi-piece mold is used and/or if a side action is used in defining the mold cavity. In certain embodiments, once the parting lines are defined, surfaces are then identified that are perpendicular to the parting lines. To assist in mold use and piece ejection, the shape geometry is modified to allow at least 1° clearance around the parting lines.

A reusable pattern, die, or mold is created 706 which defines at least one and preferably a plurality of internal mold cavities matching the shape geometry. When using amorphous alloys, the shape geometry profile substantially matches the profile of the finished part, and is designed to have each mold cavity volume sized at effectively a net-to-shape size, where the mold cavity has a tolerance less than 0.5% larger, and preferably less than 0.2 larger than the broadhead assembly or component. In certain embodiments, the mold allows the blades to be molded at a thickness of approximately 0.015 inches for fixed broadhead assemblies or approximately 0.025 inches for blades in mechanical broadhead assemblies.

The mold is created with a passageway to deliver liquid metal from an entry site to the mold cavity. A feedstock of metal alloy, typically a crystalline alloy initially, is rapidly heated to a liquid non-crystalline state 708. The feedstock may be initially formed in ingots of a selected mass which matches the desired mass of the finished product plus an allocation for any excess which may be lost in processing, such as a sprue which is later trimmed. Alternately, the feedstock may be a larger volume of material in a separate reservoir for one mold cavity or as part of a shared reservoir which can be fed simultaneously or separately to multiple mold cavities.

The liquid-state non-crystalline metal is then fed via a passageway into the mold cavity 712, typically under positive pressure. Optionally yet desirably, a negative pressure and/or partial vacuum is applied 710 to the mold cavity prior to and while introducing the liquid-state alloy. The cavity is filled with a desired amount of the liquid-state metal until it is full and packed at a desired density. The liquid-state metal is then rapidly cooled to a non-crystalline solid state 714. The vacuum is then released and the mold is opened 716. Finally, the finished broadhead component or assembly is removed from the mold 718, for example using ejector pins. After ejection, finishing steps such as trimming, drilling, polishing, sharpening, etching, coloring, labeling, etc. can be applied to the broadhead or component.

In certain embodiments, the mold is a two-piece type mold, with the two pieces each defining a portion of the mold cavity, where the two pieces can be closed to define the complete mold cavity. A two piece mold, for example, is useful to forming the broadhead assembly of FIG. 4, the planar broadhead blades shown in FIGS. 5-7 or the ferrules illustrated in FIGS. 8-9. A three or more piece mold, for example, may be useful to form the broadhead assemblies of FIGS. 1-3, the body and ferrule portions of FIGS. 5-6 and the housing and ferrule portions of FIG. 7. Optionally a multi-piece mold may include side-action components to define slots, grooves or holes in the formed pieces.

In certain embodiments for forming blades, the mold pieces define cut-out portions in the blade. In example embodiments, the mold cavity defines an open periphery volume around one or more central closed areas. The closed areas may occur where portions of the mold meet. When the formed piece is ejected the closed central areas result in open central cut-out portions in the blade. The central cut-out portions may be one opening per blade as illustrated in FIGS. 1-2 or multiple smaller openings, as illustrated in FIGS. 3 and 5.

A three piece mold, for example, is useful in forming an integral one-piece broadhead assembly with three blades. FIG. 11 illustrates a rear view of the three blade broadhead of FIG. 1 with example mold lines M showing planes through the blades which could form parting lines for a three piece mold. In this embodiment, the mold pieces each span approximately 120 degrees and meet at parting lines M along the outer forward and trailing edges of each blade. They also meet at forward and rearward locations, and define at least one liquid allow injection passage, for example along the central axis of the threaded portion 24. The inward portions of each mold piece define volumes for the broadhead body 30 and the blades 40, and meet in areas where metal material is not desired, for example to define cut-out portions 44 in each blade.

The blade sharpening process is significantly enhanced in certain embodiments of blade and broadhead assemblies made using amorphous allow molding. Traditionally with steel or broadhead blades made from other crystalline metal materials, the blades, whether formed individually or as part of an assembly, were formed with an cutting edge thickness substantially corresponding to the thickness of the planar material of the blade. In many instances this was a minimum of 0.015 inches (381 microns) for a fixed blade and 0.025 inches (635 microns) for a mechanical blade. After being formed, the blade cutting edge then had to be sharpened, for example by grinding, chemical etching, electron emission or otherwise to a desired cutting edge radius, preferably in a range of two (2.0) microns or less. This required the removal of material from the initial thickness down to the desired cutting edge radius, and could include a rough grinding step, a finish grinding step, honing and or stropping, where the grinding and honing were sometimes done at two different angles.

Using an amorphous alloy molding process, the formed blade edge thickness can be initially made with a mold radius of approximately 10 microns or less, and alternately with a radius of 5-6 microns or less. The resulting edge thickness can then be further sharpened, as desired, to a final cutting radius in the range of two (2.0) microns or less. This requires substantially less processing and removal of material than is needed with crystalline metal broadhead blades.

In certain embodiments, broadhead assemblies are formed of a single homogeneous metal alloy. Alternately, different alloys could be fed into different portions of the mold cavities to form different portions of the broadhead, with the alloys fusing at their transition points to form a single piece broadhead assembly. In still alternate embodiments, a blade may be pre-formed and held in a selected location in the mold cavity prior to introduction of the alloy. The liquid alloy is then introduced into the mold cavity and formed about a portion of the blade to form an integrated assembly. This optionally allows the blade to be constructed from a dissimilar metal or material than the body.

In further embodiments, the blades may be formed separately from the body portion and then removably attached to the ferrule portion. Alternately, the blades may be permanently attached or fused to the ferrule portion, such as by welding, for example with a laser.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come with the spirit of the invention are desired to be protected.

Claims

1. A method of making a broadhead assembly, comprising:

a. providing a reusable mold defining an internal mold cavity matching the shape geometry of a broadhead assembly with a ferrule and a plurality of integrated blades with cutting edges, wherein the mold cavity profile net-to-shape size is less than 0.5% larger than the profile of the intended finished broadhead assembly, and wherein the mold defines a passageway to deliver liquid metal from an entry site to the mold cavity;
b. heating a feedstock of metal to a liquid non-crystalline state;
c. injecting the liquid-state non-crystalline metal into the mold cavity via the passageway to fill the mold cavity;
d. rapidly cooling the liquid-state metal to an amorphous non-crystalline solid state;
e. opening the mold and ejecting the finished broadhead assembly; and,
f. sharpening the blade cutting edges.

2. The method of claim 1, wherein the amorphous alloy contains greater than 50% zirconium.

3. The method of claim 1, wherein the mold cavity profile net-to-shape size is less than 0.2% larger than the profile of the intended finished broadhead assembly.

4. The method of claim 1, wherein each blade cutting edge thickness is molded with a radius of approximately 10 microns or less, and wherein the blade cutting edges are sharpened, after ejection, to a final cutting radius of approximately 2.0 microns or less.

5. The method of claim 1, wherein said mold is a two piece mold and said broadhead assembly has two blades.

6. The method of claim 1, wherein said mold is a three piece mold and said broadhead assembly has three blades.

7. The method of claim 1, wherein said mold defines a plurality of parting lines and wherein the shape geometry allows at least 1° clearance around the parting lines.

8. The method of claim 1, comprising applying a partial vacuum to the mold cavity while injecting the liquid-state metal.

9. The method of claim 1, wherein said shape geometry defines dimples in the ferrule portion.

10. A method of making a broadhead component, comprising:

a. providing a reusable mold defining an internal mold cavity matching the shape geometry of a broadhead component, wherein the mold cavity profile net-to-shape size less than 0.5% larger than the profile of the intended finished broadhead component, wherein the mold defines a passageway to deliver liquid metal from an entry site to the mold cavity;
b. heating a feedstock of metal to a liquid non-crystalline state;
c. injecting the liquid-state non-crystalline metal into the mold cavity via the passageway to fill the mold cavity;
d. rapidly cooling the liquid-state metal to an amorphous non-crystalline solid state;
e. opening the mold and ejecting the finished broadhead component.

11. The method of claim 10, where the broadhead component is a ferrule.

12. The method of claim 10, where the broadhead component is a blade.

13. The method of claim 12, wherein the broadhead component is a blade with at least one cut-out portion.

14. The method of claim 13, wherein the blade defines cross-members which sub-divide the cut-out portion into smaller openings.

15. A method of making a broadhead component, comprising:

a. defining a shape geometry for a broadhead component;
b. using the shape geometry to determine the location for at least one parting line for at least one of a pattern, die or mold;
c. creating at least one of a pattern, die or mold defining a plurality of internal mold cavities matching the shape geometry of a broadhead component;
d. heating a feedstock of metal to a liquid non-crystalline state;
e. injecting the liquid-state non-crystalline metal into said mold cavities under positive pressure to fill the mold cavities;
f. rapidly cooling the liquid-state metal to an amorphous non-crystalline solid state; and,
g. opening the at least one of a pattern, die or mold along the at least one parting line and ejecting a plurality of finished broadhead components from the mold cavities.

16. The method of claim 15, wherein the mold cavity profiles are less than 0.2% larger that the profiles of the finished broadhead component.

17. The method of claim 16, wherein the shape geometry is a blade with a cutting edge, and comprising sharpening the cutting edges of said plurality of finished broadhead components to a final cutting radius of approximately 2.0 microns or less.

18. The method of claim 16, wherein the broadhead component is a ferrule with a length, and wherein the cross-sectional area varies along the length of the ferrule.

19. The method of claim 16, wherein the broadhead component is a ferrule and wherein said shape geometry defines dimples in the ferrule.

20. The method of claim 15, comprising applying a partial vacuum to said plurality of mold cavities while injecting the liquid-state metal.

Patent History
Publication number: 20160074932
Type: Application
Filed: Sep 4, 2015
Publication Date: Mar 17, 2016
Inventor: Robert Mizek (Downers Grove, IL)
Application Number: 14/845,328
Classifications
International Classification: B22D 17/00 (20060101); C22C 16/00 (20060101); C22C 45/10 (20060101); F42B 6/08 (20060101); B22D 21/02 (20060101);