Abstract:
An arrowhead having a combination of fixed and expandable blades is provided. The new arrowhead has three mechanically expandable blades and six fixed blades. An expandable blade is snug fitted in between two fixed blades, eliminating the need for a mechanism to hold the expandable blade during the flight. In one embodiment of the present arrowhead, the expandable blades pivotally open from the front end of the arrowhead. And in the second embodiment of the present arrowhead, the expandable blades pivotally open from the rear end of the arrowhead.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to arrowheads and broadheads. 
       BACKGROUND AND SUMMARY OF THE INVENTION 
       [0002]    Various assemblies for enhancing the performance of arrowheads have been proposed. The main design objective of an arrowhead is to enhance both the flying performance and the striking power of the arrow when hitting the target. 
         [0003]    Small arrowheads have lower aerodynamics drag and provide accurate flight pattern, but at the same time, they have lower striking power compared to the larger arrowheads. Hunters have had to choose between small arrowheads that fly accurately, or large arrowheads that do not fly accurately but have higher striking power. 
         [0004]    In order to overcome this issue and to have both power and accuracy, arrowheads with mechanically expandable blades are introduced. Mechanically expandable blades remain small in diameter when flying and before hitting the target. The arrowhead expands in diameter only upon contact with the target, creating a larger area of penetration and a wide cut surface. 
         [0005]    The expandable blades, however, have several drawbacks. If the arrowhead with expandable blades hits the target at an angle, the blades may not open causing the arrow to ricochet away from the target. Further, as the expandable blades open only after penetrating into the animal&#39;s body, they have greater tendency to bounce off from the target than the fixed blades. Moreover, expandable blades are fragile compared to fixed blades and they may break upon contact, preventing them from normal functioning and making them unreliable in operation. These limitations have been circumvented by using a combination of fixed and expandable blades. Fixed blades in this case can be smaller in size and they can act as a support for the expandable blades to guarantee their proper functioning. 
         [0006]    The following U.S. Patents are examples of arrowhead having both fixed and expandable blades. U.S. Pat. No. 6,322,464 B1 to Sestak titled HUNTING ARROWHEAD WITH BROADHEAD AND EXTENDABLE BLADES, introduced an arrowhead with one broadhead and two extendable blades, where the expandable blades pivot in a plane of movement perpendicular to the plane of the fixed broadhead blade. U.S. Pat. No. 6,554,727 B1 to Armstrong et al. titled DEFLECTION-RESISTANT ARROWHEAD HAVING BOTH FIXED AND MECHANICALLY EXPANDABLE BLADES, proposed an improved arrowhead with a spear-point blade mounted on the tip of the arrowhead to provide entry into the target before the expandable blades are deployed. In a related invention, U.S. Pat. No. 8,062,155 B2 to Butcher titled ARROWHEAD HAVING BOTH FIXED AND MECHANICALLY EXPANDABLE BLADES, the number of expandable blades is increased and two sets of expandable blades are located proximate to the base of the fixed blade portion to allow the fixed blade to penetrate the target before the expandable blades are deployed. 
         [0007]    Although several mechanisms have been proposed for arrowheads having both fixed and moving blades, the design of the arrowheads can still be improved and modified for higher effectiveness. In the present invention, an arrowhead with multiple fixed and expandable blades is proposed, where the expandable blades are mounted between the fixed blades to ensure the opening of the expandable blades and the penetration of the hunting arrow into the animal&#39;s body. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention introduces an improved arrowhead having both fixed and expandable blades. Three sets of blades are mounted at the tip of the arrowhead. Each set of blades is constituted of two fixed blades and one expandable blade, wherein the expandable blade is located in between the two fixed blades. The blades are situated close to the tip of the arrowhead in order to minimize the time between entry of arrow tip and the beginning of deployment of the expandable blades. The present design ensures the proper opening of the expandable blades and it protects the moving blades from failure and breakdown. 
         [0009]    The arrowhead includes a support body having substantially conical tip portion with nine longitudinal slots, grouped three by three, formed in the sides thereof. Each group of three slots serving as a housing for one expandable blade located in between two fixed blades. The expandable blades are in retracted configuration during arrow flight. The fixed blades are triangular shaped with a cutting edge extending rearwardly from the tip of the arrowhead. At the base of the arrowhead a threaded male connector is attached to allow the arrowhead to be mounted in a female threaded connector at the front of a hunting arrow shaft. 
         [0010]    The first objective of the present invention is to increase the rigidity and robustness of the arrowhead, and to minimize the risk of its failure upon impact. The two fixed blades on both sides of the expandable blade act as a support for the expandable blade and prevent its potential breakdown. Further, fixed blades act as back up if mechanical blades fail to deploy. 
         [0011]    The second objective of the present invention is to have a wider range of cutting surface with more damage to bone and vitals of an animal resulting in larger bleed out of animal causing animal to parish quickly acting as a humane form of hunting and easier to track blood trail to retrieve animal. 
         [0012]    The third objective of the present invention is to minimize the risk of the expandable blade from staying closed when the tip of the arrow strikes the target. The expandable blades are placed in between fixed blades and they gradually expand while the fixed blades cut the animal&#39;s body and penetrate into the target. 
         [0013]    The fourth objective of the present invention is to minimize the chance of the hunting arrow from being bounced off from the target. The fixed blades guarantee the initial cut of the animal&#39;s body and prevent the deflection of the arrow. 
         [0014]    The fifth objective of the present invention is to use the hunting arrow for bow fishing. The fixed blades act as a hook for retrieval of the fish. 
         [0015]    The aforementioned objectives of the present invention are attained by a specific combination of fixed and expandable blades. Other advantages and novel features of the present invention will become readily apparent from the following drawings and detailed description of preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Embodiments herein will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the scope of the claims, wherein like designations denote like elements, and in which: 
           [0017]      FIG. 1  shows the front view of the arrowhead; 
           [0018]      FIG. 2  shows a perspective view of the arrowhead with expandable blades in retracted position; 
           [0019]      FIG. 3  shows a perspective view of the arrowhead with expandable blades in open position; 
           [0020]      FIG. 4  shows the longitudinally grooved slots at one facet of the main body with the slot that matches a fixed blade; 
           [0021]      FIG. 5  shows the longitudinally grooved slots at one facet of the main body with the slot that matches an expandable blade; 
           [0022]      FIG. 6  shows the front view of the main body when all blades are removed; 
           [0023]      FIG. 7  shows the back view of the main body when all blades are removed; 
           [0024]      FIG. 8  shows the perspective view of the main body when all blades are removed; 
           [0025]      FIG. 9  shows another embodiment of the expandable blade with the expandable blades being mounted on the two fixed blades with a mechanism to allow opening of the blade from the rear side of the arrowhead; 
           [0026]      FIG. 10  shows the perspective view of the main body when all blades are removed in another embodiment of the present invention; 
           [0027]      FIG. 11  shows another embodiment of the present invention without expandable blade; 
           [0028]      FIG. 12  shows another embodiment of the present invention with conical tip at its distal end; and 
           [0029]      FIG. 13  shows another embodiment of the present invention with four fixed blade and optional expandable blade. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0030]      FIG. 1  shows the front view of the arrowhead. The arrowhead includes a triangular base pyramidal shaped main body  10 , which supports six fixed blades  11  and three expandable blades  12 . In  FIG. 2 , the perspective view of the main body  10  is shown which includes a connecting shaft  26  with a male threaded connection to mount the main body  10  on an arrow shaft (not shown). The main body  10  can be made of steel alloy, glass fiber reinforced plastics, stainless steel, or other metal, depending on the type and distance of target. The expandable blades  12  in  FIG. 2  are held in retracted position with a stretchable elastic ring (not shown). The expandable blades  12  are set in between the two fixed blades  11  resulting in a reduced aerodynamics drag during the flight and an accurate flight pattern. 
         [0031]      FIG. 3  shows the expandable blades  12  in open position when the arrowhead hits the target. When the blades are open they increase the cutting surface and they inflect more damage to animal&#39;s body. The tip  15  of the main body  10  is pyramidal shaped with plurality of lateral cutting edges  16 . The tail  17  of the main body  10  is smoothly connected to the shaft  26  with a shallow angle to prevent the flow separation and turbulence behind the arrowhead and to reduce the aerodynamics drag of the arrowhead. 
         [0032]    As shown in  FIG. 4 , each facet of the triangular base main body  10  supports two pairs of fixed blades  11 , and one pivotally mounted expandable blade  12 . At each facet of the main body  10  two non-parallel slots  13  are grooved to receive two fixed blades  11 . Another slot  14  is grooved to receive one expandable blade  12 . The slot of the expandable blade ( 14 ) is between the slots of the fixed blades ( 13 ) and it is shorter than the other two. This configuration allows the opening of the expandable blade  12  shortly after the fixed blades  11  have penetrated into the animal&#39;s body, and reduces the risk of the expandable blade  12  to break or to stay closed after hitting the target. Furthermore, the two fixed blades  11  are not parallel. They make an acute angle with each other at the tip of the arrowhead to increase the cutting ability of the arrowhead. Moreover, the distance between the tips of the two fixed blades  11  is such that at each face of the main body, the expandable blade  13  can be snug fitted between two fixed blades  11 , and, as a result, there is no need to keep the three expandable blades closed with an elastic rubber band. Alternatively, the fixed blades  11  may be integrally formed with the main body  10  as a whole unit. 
         [0033]    The hunting arrow can also be used for fish hunting. In this case six fixed blades  11  ensure the retrieval of the fish when the arrowhead penetrates into the fish&#39;s body. The expandable blades  12  and the fixed blades  11  can be made of steel alloy, rigid plastic, stainless steel, or other metal, depending on the type of the target. 
         [0034]    Again referring to  FIG. 4 , the fixed blades  11  have a hole  23  from which a pivot  22  passes and it rigidly fixes the blades  11  to the main body  10 . The sharp cutting edge  24  of the fixed blade  11  is straight as shown in  FIG. 4 . Alternatively, the sharp cutting edge  24  can be curved. At each of three sides of the pyramidal shaped main body  10  a single pivot  22  is inserted through a hole  25  on the main body and it secures the three blades (two fixed and one expandable) together. 
         [0035]    In  FIG. 5 , the sharp edges  18  of the expandable blades  12  are shown. In closed position, the sharp edges  18  are placed within the slots  14  to protect them from damage and to make the arrowhead easier to handle by reducing the risk of cut fingers. A spur  19  is attached at the leading edge of the expandable blade  12 , and it is extended outwardly away from the main body  10  when the expandable blades are in retracted position. The spur  19  enables the expandable blade  12  to start its deployment after the arrowhead hits the target and penetrates into the animal&#39;s body. The tail  20  of the expandable blade  12  is rounded and a hole  21  is formed at the end of each expandable blade  12  to allow free rotation of the blade  12  around the pivot  22 . 
         [0036]    In  FIG. 6 , the front view of the main body  10  is shown when all blades are removed. In total, there are six slots  13  to receive six fixed blades  11 , and three slots  14  to receive three expandable blades. The triangular shape of the main body  10  allows an easy installation of 9 blades on a single arrowhead. In  FIG. 7 , the back view of the main body  10  is shown, and the perspective view of the main body is shown in  FIG. 8 . 
         [0037]    In  FIG. 9 , another embodiment of the arrowhead is presented, wherein two expandable blades  27  and  28  are between two fixed blades  11  and they are pivoted to the sides of the fixed blades  11 . In this embodiment, the expandable blades  27  and  28  are not installed on the main body  10 , and, instead, they are mounted on the fixed blades  11 . In  FIG. 9   a  the expandable blades  27  and  28  are in a retracted position, with the expandable blades  27  and  28  being hidden between the fixed blades  11 , thus reducing the aerodynamics drag of the arrowhead during the flight. 
         [0038]      FIG. 9   b  shows the blades arrangement when the arrowhead hits the target and the expandable blade  28  starts rotating around its pivot  30  in the clockwise direction, pushing downward at the same time the distal end of the expandable blade  27  and making it to rotate in the counterclockwise direction around its pivot  29 . 
         [0039]    As shown in  FIG. 9   b  the expandable blade  27  is fully opened when the central axes of the two blades  27  and  28  are perpendicular to each other. After the expandable blade  27  is fully opened, by further rotation of the expandable blade  28  in the clockwise direction, the expandable blade  27  will be locked in its position and it will stay open. In the locked position, shown in  FIG. 9   b , the distal end of the expandable blade  27  will be positioned in a small recess  34  in the main body as shown in  FIG. 10 . In the locked position, the angle between the axes of the two blades  27  and  28  is larger than a right angle (90 degree). Therefore, when the arrowhead penetrates into the animal body the two blades  27  and  28  stay open with their cutting edges  32  and  31  facing forward resulting to a larger cut and hemorrhage. 
         [0040]    Base on expandable blade length, the small recess  34  can be designed in the main body. There is a possibility of no recess in the main body with small length of the expandable blade  27  in another embodiment of the present invention. 
         [0041]    In another embodiment of the present invention, there is no expandable blade between two fixed blades  11 . Three sets of two fixed blades  11  increase the cutting ability of the arrowhead by itself as shown in  FIG. 11 . The fixed blades  11  are rigidly fixed to the main body  10 . 
         [0042]    In another embodiment of the present invention, the tip  45  of the main body  10  is conical shaped with sharp end  46  as shown in  FIG. 12 . The tip  45  of the main body  10  makes an important role for penetration purposes. 
         [0043]    In another embodiment of the present invention as shown in  FIG. 13 , there are two sets of fixed blades  11  which are mounted in the conical body  50  with the sharp tip  55  at its distal end. The expandable blade (not shown) can be placed between two fixed blades for gradually expand while the fixed blades cut the animal&#39;s body and penetrate into the target. 
         [0044]    The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 
         [0045]    With respect to the above description, it is to be realized that the optimum relationships for the parts of the invention in regard to size, shape, form, materials, function and manner of operation, assembly and use are deemed readily apparent and obvious to those skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.