Abstract:
A magnetic blade retainer for an expandable broadhead utilizing the properties of magnetic attraction to reliably secure a plurality of blades completely within respective blade channels so that an expandable broadhead may closely resemble the flight properties of a practice arrow tip yet lethally expand upon impact with a target. Extraneous parts are eliminated, but a strong, disc magnet is inset or integrated into the forward portion of a broadhead tip assembly. Each blade is provided with a magnetic, flat forward end. The interaction of the flat forward end and the magnet magnetically retain each blade. The magnetic bond is broken when the arrow penetrates a target. An actuating spike further transfers the impact energy to each blade. The forces on the actuating spike then drag each blade backward and each blade extends as the rearward forces are translated by the wedging surface near the end of the channel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application claims priority under 35 U.S.C. §119(e) to U.S. Patent Application Ser. No. 62/085,331 entitled “Magnetic Blade Retainer for a Broadhead” and filed on Nov. 27, 2014. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not applicable. 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to arrowheads and more particularly to mechanical broadhead arrow tips with deployable blades. 
     2. Description of the Related Art 
     The archery industry has developed variations for folding the blades of a broadhead to serve bow hunters in the field. In these mechanical or expanding-blade broadheads the blades are operably coupled in a manner to allow the blades to move from an in-flight, retracted position to an on-impact, deployed position. The expandable broadhead is beneficial in that it is more aerodynamic than fixed-blade broadheads where the blades may serve as unintended wings and alter the intended flight of the arrow which is traveling at more than 350 feet per second. At that speed, any outside force or imperfection in the broadhead. The goal of a mechanical broadhead with expandable blades is to mimic flight characteristics similar to those of a field point tip while allowing for maximum cutting diameter and lethality more akin to fixed blade broadheads. 
     The first mechanical broadheads in the industry provided one or more blades partially folded such that the cutting edge was on the radially inward edge of the blade and the entire blade opened by pivoting around a point near the rear of the broadhead body. These blades require rotation from a retracted position to a deployed position about a rearward pivot point upon impact within a target, thereby exposing the cutting edge formed on the blade. Using this type of mechanical broadhead results in a substantial loss in kinetic energy to the blade rotating in a direction opposite to the flight path to end in a deployed position. As a result, less kinetic energy is available for target penetration on impact. In the field, this negative energy transfer leaves the broadhead less lethal resulting in hunting impacts which may only injure the animal. An injured animal may wonder out of an archer&#39;s sight. The archer will need to spend a great deal of time searching for the animal, but in many cases he will be unsuccessful which will leave the animal to die a protracted death as a result of its injuries and will ultimately result in a waste of the game animal. 
     With increasing frequency mechanical broadheads include one or more blades which longitudinally slide relative to the body from the in-flight, retracted position to the on-impact deployed position. During flight, the blades are closely positioned to the body, and upon impact the blades slide rearwardly through a range of motion to the deployed position. Specifically, the blades in this sliding-type mechanical broadhead extend from a longitudinal groove formed in the body such that the cutting edge of the blades extend radially outward from a partially-exposed to fully-exposed diameter. The current designs of such broadheads are less robust or reliable compared with other types of mechanical broadheads. Pins, elastics, gages, rubberbands, or other retaining mechanisms operably couple the blade to the body of the broadhead adding complexity to the design and opportunities for parts to be damaged during use, storage, or shipment. The mechanisms used to retain the broadhead blades during nocking and flight add a layer of unreliability to the broadhead causing them to malfunction at inopportune times such as in-flight or upon impact. Even though a few prior art references have paid passing, cursory mention to the idea of employing magnets in various elements of a mechanical broadhead body, no invention has disclosed how to implement the magnet, a successful implementation has not been disclosed. A need exists to successfully employ a magnet as the sole retaining device for the blade of an expandable broadhead. Despite recent developments in the broadhead art, and in particular use of powder injection molding for the manufacture of components adding significant flexibility in the design and manufacture of blade designs, broadheads still need improvement 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a new blade retainer for a broadhead arrow tip attachable to an arrow shaft, the blade retainer comprising a blade having a planar or flat surface on its leading end, while a magnet is disposed in the broadhead tip resulting in the blade being securely held to the magnet by the magnetic attraction of the flat blade end to the magnet. In the preferred embodiment, the blade retainer for an expandable broadhead comprises a flat forward face of a blade and a magnet disposed in the tip of the broadhead wherein the magnet acts to hold the blade in a compressed disposition by forces of magnetic pull between the magnet and the flat forward face of the blade. 
     In the preferred implementation of the invention, the broadhead is adapted for attachment to an arrow-shaft. The broadhead is formed of a body attachable to a tip. The magnet is integrated within the tip. The broadhead body is provided with channels within which a plurality of blades may be installed. In this embodiment, the blades slide rearwardly to an outwardly extending position when the broadhead impacts a target. The blades may be manually returned to their stowed position when they are slid forward to return to the compressed, in-flight blade position and again held by the magnetic blade retainer until the next frontal impact. In this preferred implementation, the blades are entirely hidden within the channels when they are folded in the compressed, in-flight position. In one implementation of the invention, the blades will be provided with a protrusion which exceeds the external margins of the body. These protrusions may be spikes or hooks integrated into the blade. These actuating spikes protrude from the exterior of the broadhead to contact the target and transfer the force of impact to the blade such that the blade begins to move rearwardly with enough force to overcome the magnetic forces of attraction holding the blade to the magnet. Therefore, the actuating spikes act to assist with breaking the magnetic bond holding the blades in a compressed position and further act to transfer energy to drag the blades within the channels to an expanded, cutting position. In the preferred embodiment, a plurality of blades are preferred; however, each blade will move independently of the other blades. Each blade has a flat forward face which, when folded, is attracted by magnetic force to the magnet in the tip. The magnetic attraction of the flat forward face of each blade is held securely by the flat surface of a powerful magnet inset in the tip. 
     With the arrangement provided herein, the rearward and resulting radial shifting of the blades results from the entry of the broadhead into the object upon contact. The deployed blades will expose hide or flesh cutting surfaces to cause maximum damage to the impacted target. 
     The body for the preferred broadhead using the magnetic retainer will be sufficiently sized to receive a plurality of folded blades within the external margin of its radial circumference. External threading will be provided on each of the distal and proximal ends. The threading on the proximal end will cooperate with the arrow shaft. The distal threading will cooperate with threading on the tip so that the tip may be removably attached to the body. Sliding channels punch all of the way through the distal end of the body. The sliding channels provide the paths through which blades may slide during deployment and then back through compression or even replacement when blades become damaged. In the preferred implementation, a bulbous sliding mechanism is integrated into the blade to facilitate the secure sliding in the channels and act as a channel stopper to halt the blade a the end of the channel. The blade further comprises a protruding, actuating spike near the bulbous structure and the flat distal surface abutting the magnetic tip. The proximity on the blade between the spike, the face, and the bulbous structure will facilitate maximum energy transfer upon impact. In the preferred implementation, the entirety of the blade is disposed within the body until it is deployed by impact with a target when the protruding spike actuates a separation of the magnetic force holding the blade to the magnetic tip. 
     The employment of the present invention permits successful sliding of an entire, lethal blade within a broadhead body without any external parts or retainers. The magnetic blade retainer will have advantageous uses in any broadhead having blades which move in any manner including but not limited to folding, articulating, pivoting, or sliding. There is no requirement for extraneous fasteners such as pins, rods, or rings to hold the blades in place. The only retaining force is provided by magnetic forces. When the blades are compressed for storage, nocking, or flight, the only visible portion of the blade is the integral spikes used to transfer the kinetic energy and deploy the blades upon impact with the target. The open-on-impact feature of the present retaining member is very important for user safety and effective harvesting of game. Stowed blades will allow the arrow to fly straighter and strike the intended target with more accuracy. The deploying blades will increase the cutting diameter and ensure that the target will not escape to die in isolation. With part count minimized, failure risk in minimized and noise from rattling of blade components is reduced. 
     The foregoing has outlined, in general, the physical aspects of the invention and is to serve as an aid to better understanding the more complete detailed description which is to follow. In reference to such, there is to be a clear understanding that the present invention is not limited to the method or detail of construction, fabrication, material, or application of use described and illustrated herein. Any other variation of fabrication, use, or application should be considered apparent as an alternative embodiment of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings further describe by illustration, the advantages and objects of the present invention. Each drawing is referenced by corresponding figure reference characters within the “DETAILED DESCRIPTION OF THE INVENTION” section to follow. 
         FIG. 1  is a partially disassembled, perspective view of the blade retaining magnet in a broadhead according to the present invention. 
         FIG. 2  is a partially disassembled, perspective view of the magnetic blade retainer implemented in an alternative broadhead embodiment according to the present invention. 
         FIG. 3  is a partially transparent side view of the embodiment illustrated in  FIG. 2 . 
         FIG. 4  is a perspective view of a blade according to the present invention when removed from the broadhead body. 
         FIG. 5  is a tip-end view of a blade according to the present invention when removed from the broadhead body. 
         FIG. 6  is a side plan view of a blade according to the present invention when removed from the broadhead body. 
         FIG. 7  is a perspective view of the broadhead body for the preferred implementation of the magnetic retainer with the tip, magnet, and blades removed. 
         FIG. 8  is a tip-end view of the broadhead body shown in  FIG. 7 . 
         FIG. 9  is a side plan view of the broadhead body shown in  FIGS. 7-8 . 
         FIG. 10  is a rear perspective of a tip assembly cap removed from a broadhead body according to the preferred implementation of the magnetic retainer. 
         FIG. 11  is a partially transparent view of a tip assembly cap removed from a broadhead body according to the preferred implementation of the magnetic retainer. 
         FIG. 12  is a tip-end view of a tip assembly cap removed from a broadhead body according to the preferred implementation of the magnetic retainer. 
         FIG. 13  is a sectional view taken along line B-B in  FIG. 12 . 
         FIG. 14  is a rear perspective of a tip assembly cap removed from a broadhead body according to another implementation of the magnetic retainer. 
         FIG. 15  is a partially transparent view of a tip assembly cap removed from a broadhead body according to another implementation of the magnetic retainer. 
         FIG. 16  is a tip-end view of a tip assembly cap removed from a broadhead body according to another implementation of the magnetic retainer. 
         FIG. 17  is a sectional view taken along line D-D in  FIG. 16 . 
         FIG. 18  is a side plan view of a magnetic broadhead with the blades in a retracted position. 
         FIG. 19  is a tip-end view of a magnetic broadhead with the blades in a retracted position. 
         FIG. 20  is a side plan view of another magnetic broadhead with the blades in a retracted position. 
         FIG. 21  is a tip-end view of another magnetic broadhead with the blades in a retracted position. 
         FIG. 22  is a perspective view of a magnetic broadhead with the blades in a retracted position. 
         FIG. 23  is a perspective view of a magnetic broadhead with the blades in a deployed position. 
         FIG. 24  is a perspective view of another magnetic broadhead with the blades in a retracted position. 
         FIG. 25  is a perspective view of another magnetic broadhead with the blades in a deployed position. 
         FIG. 26  is a perspective view as shown in  FIG. 23  with cross sectional indicators. 
         FIG. 27  is a longitudinal sectional view taken along line A-A in  FIG. 26 . 
         FIG. 28  is a perspective view as shown in  FIG. 25  with cross sectional indicators. 
         FIG. 29  is a longitudinal sectional view taken along line C-C in  FIG. 28 . 
         FIG. 30  is a side plan view of a magnetic broadhead showing the blades in a deployed position. 
         FIG. 31  is a tip-end view of  FIG. 30 . 
         FIG. 32  is a side plan view of another magnetic broadhead showing the blades in a deployed position. 
         FIG. 33  is a tip-end view of  FIG. 32 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In accordance with the accompanying drawings, applicant&#39;s magnetic blade retainer for a broadhead includes a magnet  40  and a blade  30  for use with a broadhead  1 . As illustrated in  FIGS. 1-3 , when the magnetic blade retainer is implemented, it will be joined with other broadhead  1  components including a body  20  and a tip assembly cap  10 . The magnet  40  occurs within the tip assembly cap  10 . Each blade  30  lies completely within the body  20  in a blade channel  23 . In the preferred instance, when each blade  30  is folded, it is contained within the external margins of the body  20 . When fully assembled, each blade  30  is slidably fixed in a blade channel  23  and the magnet  40  lies in the magnet cavity  14  between the body  20  and the tip  11 . See  FIG. 3 . The cooperation of the respective threaded aspects of the tip assembly cap  10  and the body  20  secure the body  20  to the tip  10 . The body blade channel  23  aligns with the tip blade channel  13  to allow full movement of each blade  30  from the stowed or in-flight, compressed position to the deployed, expanded position. The proximal end of the body  20  is provided with a mechanism to attach to an arrow shaft. As shown in  FIGS. 1-3 , a threaded arrow shaft receiver  25  will permit the distal end of an arrow (not shown) to be joined with the broadhead  1 . 
     The planar, or flat forward face  32  of each blade is held securely by forces of magnetic attraction to the flat surface  42  of a powerful magnet inset in the tip. With reference to  FIG. 3 , the preferred magnet  40  is a disc-style magnet with very strong magnetic properties and having a distal face  41  and a proximal face  42 . The magnet  40  desirably presents at least a proximal face  42  in order to allow maximum magnet attraction between the magnet and the front face  32  of the blade  30 . In the preferred embodiment, the magnet  40  lies completely within the tip inset, magnet cavity  14  beyond the cap threading  12 . The blade  30  slides completely within the channel created by the alignment of the body channel  23  and the tip channel  13  when the tip assembly or cap  10  is secured to the body  20 . 
     The blade  30  has important elements to facilitate the proper functioning and use of the magnetic retainer for the broadhead  1 . In  FIGS. 4-6 , a blade according to the preferred embodiment will be comprised of a flat forward face  32  at the leading edge of the blade. The forward face  32  is formed to lie perpendicular to the longitudinal surface of the blade, broadhead, and thus flight path of the broadhead. The flat forward face  32  provides an optimal surface to interact with the magnet  40 , particularly the flat proximal face  42  of the magnet shown in  FIG. 3 . A bulbous sliding mechanism, bulge, boss, jut, or other protruding structure  33  near the forward face  32  of the blade  30  fulfills two objectives in the preferred implementation of the present invention. First, the protrusion  33  slidably secures the blade  30  in the blade channel  23  by interaction with, or retention by the blade channel lip  27  better shown in  FIG. 7 . Next, the protrusion  33  acts as a channel stopper for the blade  30  so that the blade  30  is expanded to a maximum cutting diameter but held at that location and not allowed to exit the broadhead. An actuating spike, also called a hide hook  31  extends vertically to protrude toward the distal end of the blade  30 . In the preferred embodiment, the actuating spike  31  is disposed directly above the flat forward face  32  of the blade and the bulbous sliding structure  33 . The blade  30  has a cutting edge  35  and a supporting edge  36 . The blade  30  is further supported by the interface fit of the angled rear edge  34  against the angled wedging surface  24  of the blade channel  23  when the blade  30  is in a closed, in-flight position. This design also maximizes the cutting surface  35  and diameter of destruction of the blade. In preferred designs, the blade  30  may also have serrations  37  placed in the cutting edge  35 , again to enhance the destructive cutting power of the broadhead  1 . Windows or slots  38  may be excised from the blade  30 . This design feature has the added benefit of reducing the weight of the blade  30  which optimizes immediate deployment at impact. 
     Referring to  FIGS. 7-9 , the body  20  of the present invention is a longitudinally extending body with a radial circumference. The body  20  is substantially comprised of a tail and arrow shaft attachment section  25 , a support section, and a cap receiver section. Multiple blade channels  23  occur in the support section and the cap receiver section to receive multiple blades  30  within the external margins of the body. For assembly, the blades  30  are inserted into the channels  23  and the cap  10  is secured with the body threads  22 . See also  FIGS. 1-3 . When assembled, the cap  10  and the body  20  are radially aligned and share one external margin. To better secure the body  20  to the cap  10  and complete the blade channel  23  for smooth blade actuation, a planar distal face  21  is provided in the portions of the body leading end not traversed by the blade channels  23 . A body rim  26  acts as a stop to abut the cap  10  when the cap  10  and body  20  are assembled. The performance of the channels  23  is maximized by the inclusion of a lip  27  and a wedging surface  24  within each channel. The lip  27  cooperates with the bulbous bulge  33  of the blade  30 . The bulge  33  slides within the channel  23  and is retained by the lip  27 . When the magnetic pull of the magnet  40  on the forward blade face  32  is disrupted, the blade  30  begins to slide rearwardly. The rear edge  34  of the blade will depart the channel  23  and the supporting edge  36  will slide against the wedging surface  24  and urge the blade to exit the channel  23  and continue to the open or deployed position. When the bulge  33  comes to the rear of the channel  23  it will perform its second task which is to stop the blade at the end of the channel. The channel stop  33  comes into contact with the channel lip  27  and the support edge  36  of the blade  30  has its angle set by the pitch of the wedging surface  24 . The interference fit between the lip  27  and the wedge surface  24  will hold the blade  30  tightly, guide it toward the rear of the channel, and prevent the entire blade  30  from exiting the back of the channel  23 . In the preferred embodiment, the pitch of the wedging surface  24  will be set at forty-five degrees) (45°). 
     The tip assembly cap  10  is isolated in  FIGS. 10-13 . In the preferred embodiment, facets provide a penetrating end consisting of three cutting surfaces  15  and three cutting edges  16 . An alternative tip design is shown in isolation in  FIGS. 14-17  where a penetrating end consisting of a plurality of cutting surfaces  15  and a plurality of cutting edges  16 . The tip  11  is the convergence of the cutting edges  16  and the space between creates the cutting surfaces  15 . In either embodiment, it is preferred that a cutting edge  16  is aligned with tip blade channels  23 , and therefore the body blade channels  23 . See illustration of this alignment in  FIGS. 30-32 . The penetrating end enhances the entry of the blade cutting edge  35  and thus the lethality of the broadhead as it enters its target. The preferred threading  12  for the cap  10  to be joined with the body  20  is illustrated in  FIGS. 10-17 . The cap threading  12  will begin at the rear most portion of the cap  10  to mate with the forward most body threading  22 . The cap threading  12  will terminate with the end of the blade channels  13  such that the magnet  40  lying in the magnet cavity  14  will be forced into direct contact with the blade flat face  32  when the blade  30  is inserted into the blade channel  23  and the cap  10  is threaded to the body  20 . 
     With reference to  FIGS. 18-22 , the broadhead  1  is shown fully assembled but with the blades  30  in a closed, compressed position. The broadhead  1  is ready to be joined with an arrow shaft (not shown) and nocked, aimed, and loosed. The compressed, blades  30  are fully hidden so that only the actuating spikes  31  are visible. Looking through the top of the channel, the cutting edge  35  can be viewed. The broadhead in this configuration resembles or is very similar to the arrow tips, called field point or target point tips, used by archers when target practicing. The similarity between the present broadhead and the practice tips will maximize the consistent, trustworthy flight of the arrow so that the archer may hone the accuracy of his aiming skills. Then, when the archer&#39;s accuracy is vital to the successful destruction of a target, the broadhead  1  is more likely to perform as expected by the archer and result in a lethal first contact. 
     Referring to  FIGS. 22-25 , the before and after—closed to open—illustrations show the conversion of the target point-like broadhead to the expanded broadhead for cutting destruction. During use, the actuating spike  31  makes contact with the target and breaks the magnetic bond between the magnet  40  and the front face  32  of the blades  30  shown in  FIGS. 1-17 . The magnetic bond retains the blade  30  in the compressed formation until the leading end of the broadhead  1  comes into contact with a target. Upon contact, the penetrating tip  11  and cutting edges  16  and cutting surfaces  15  initiate entry of the broadhead  1  into the target. Once the penetration reaches the actuating spikes  31 , the force against the spikes  31  will completely separate the blade  30  front face  32  from the magnet  40 . 
     Reviewing  FIGS. 26-29  will illuminate how this action breaks the magnetic bonds and begins the sliding of the bulb  33  of each blade  30  in the respective cap channels  13  and aligned body channels  23 . The force of impact on the spikes  31  acts to slide the blades  30  back toward the arrow shaft, pushing the blades  30  against the wedging surface  24  until the bulb  33  abuts the channel lip  27 . The exposed cutting surfaces  35  enlarge the entrance wound caused by the broadhead  1  to the target. 
     The figures are presented to show the broadhead  1  in sets dictated by the broadhead versions. In each set of illustrations, the blades  30  are shown in a first position and a second position from various angles. In the first position shown in  FIGS. 22 and 24 , the blades  30  are compressed and the broadhead is ready for nocking, aiming, loosing, flight and initial penetration. Upon impact, the blades will make a smooth transition from the first position to the second position. In the second position shown in  FIGS. 23 and 25 , the blades  30  are extended as they will be after initial penetration to a fully open position as they will be when the impact is completed and the arrow has come to rest in its target. 
     With continuing reference to the sectional views of  FIGS. 26-29 , when in the extended disposition, the wedging surface  24  supports the blade support edge  36 . The blades  30  are urged toward the extended disposition during passage of the broadhead  1  through the target as result of the force generated on actuating spike  31  upon impact and penetration of the tip  11 . The transverse component of the force generated on the portion of the blade  30  forward of the point of contact with the wedging surface  24  being greater than the transverse component of the force generated on the portion of the blade  30  rearward of the point of contact with the wedging surface  24  continues to force the blade  30  toward an open, expanded position. The proximity on the blade between the spike, the face, and the bulbous structure will facilitate maximum energy transfer upon impact. 
     Referring again to  FIGS. 31 and 33 , the cutting radius of an expanded broadhead when the blades are extended, compared with the end views of the blades  30  when retracted (see  FIGS. 19 and 21 ) is immediately apparent. The attributes of the present invention will allow cutting diameters to be maximized. By way of example and not by way of limitation, the cutting diameters will range from 1.75 inches to 2.25 inches. 
     After use, the blades  30  are returned to their blade channels  13  and  23  by manual intervention of the archer. An archer may choose to clean, repair, or replace used blades  30  after use but once prepared, the blades are manually laid flat in the blade channels  23 ,  13  and the magnetic connection with the forwardly disposed magnet  40  is renewed. The renewed attraction will hold the blades  30  once again in a retracted, closed position as illustrated for example in  FIGS. 18-22 and 24 . 
     A broadhead  1  implementing the instant technology will desirably be sold separately from arrow shafts for purchase by archers. The archer will couple the broadhead with an arrow shaft by complementary threading or other acceptable means of joinder. The present invention can be implemented with any broadhead and therefore will fit any arrow size. The broadhead  1  is sold assembled, but may be disassembled as illustrated in  FIGS. 1-3  when the cap  10  is screwed off of the body  30  thereby exposing the opening of the blade channels  23  in the body  20 . When disassembled, the blade bulb  33  can slide free of the channel at the front face  21  of the body. This feature will permit blade replacement as may be necessary for selectable blade use or replacement of dulled or damaged blades  30 . The disassembly of the broadhead  1  will also expose the magnetic area. The magnet  40  may be free standing and separable as illustrated in  FIGS. 1-3 , or it may be fabricated with the cap  10 . The placement of the magnet  40  will be desirably disposed near the front of the broadhead  1  to achieve the objectives stated herein. The magnet&#39;s placement near the tip of the broadhead  1  will provide the broadhead with better balance and a forwardly disposed weight to maximize optimal flight attributes of the arrow. The weight-forward model will also reduce deflection on steeply angles shots. 
     The blades  30  may be fabricated of any material that will meet the objective of a broadhead blade so long as the flat front face  32  of the blade  30  is comprised of a material with an affinity for, or substantial attraction to a magnet force. The magnetic properties of the front face  32  of the blade may be integral to or applied to the blade  30  and or blade face  32 . The bulb  33  may be an integral part of the blade  30  or joined or coupled with the blade. The actuating spike  31  is desirably fabricated as integral to the blade  30  but may be joined with the blade as a separate component or as part of addendum to the blade comprising the spike, magnetic affinity aspect, and sliding bulb. The implementing broadhead  1  is desirably fabricated of a strong metal material such as aircraft-grade aluminum, steel, or an alloy. At least the cutting surfaces of the blade will be manufactured from materials such as stainless-steel and may be hardened, sharpened, or diamized by known techniques. 
     The present invention has refined and perfected a simple device for retaining the blades of an expandable broadhead and then also implementing the reliable expansion of the blades upon impact, and only upon impact. Because the blades are independently held to the retaining magnet, the part count is minimized, resulting in lower manufacturing costs and ease of assembly. The present invention has no need for fasteners, blade clips, blade set screws, O-rings, elastics or similar parts. Further, the present invention does not employ connecting rods or other additional translating ring components to connect blades together. With part count minimized, failure risk in minimized. The magnetic retainer of the present invention will reduce noise from rattling of blade components. 
     Regardless of the broadhead style or tip style used to implement the present invention, multiple blades will be distinctly preferred. The preferred embodiment will utilize three blades having their own blade channels in the body and cap and having their own independent contact point with the magnet. In the preferred embodiment, the blades move independently of one another, but joint movement will be possible with slight modifications. The magnet blade retainer will primarily serve  100  grain arrows but can be employed for any arrow weight. 
     It is further intended that any other embodiments of the present invention which result from any changes in application or method of use or operation, method of manufacture, shape, size, or material which are not specified within the detailed written description or illustrations contained herein are yet considered apparent or obvious to one skilled in the art are within the scope of the present invention.