Patent Application
20120172159
This invention relates to archery arrow tips, and more particularly to archery broadhead arrow tips.
Broadheads are often used by bow hunters while hunting large game animals. The broadhead generally has two or more sharp blades extending from the point. The blades form a wide cutting edge that cause massive bleeding once striking the target.
Broadheads are used in hunting popular big game animals such as deer, elk, antelope, bear, and elephants. The broadhead promotes internal bleeding upon impact as opposed to the shock or concussion produced by a rifle bullet.
Broadheads must be designed such that they can penetrate the hide, and in some circumstances, the bone of the target animal. Ideally, the hunter will aim for the lungs, or other vital organs of the animal to achieve a fast kill. The extended blades of the broadhead provide a large cutting surface to quickly bring down the target animal.
There are two main types of broadheads used today, mechanical broadheads and fixed-blade broadheads. Mechanical broadheads deploy the blades upon contact with the target. Mechanical broadheads are more streamlined in flight but are less effective at penetrating the target as a portion of the impact energy is absorbed to deploy the blades.
Fixed-blade broadheads have blades that are fixed into the open position. While sacrificing some flight characteristics, fixed-blade broadhead cut on impact in a much more efficient manner than mechanical broadheads. The blade creates a better wound channel for blood flow improving the likelihood of developing a good blood trail. The fixed-blade broadhead generally cuts deeper because it does not loose energy in the process of opening the blades as is common with mechanical broadheads. Fixed-blade broadheads are also stronger than comparable mechanical broadheads as there are no moving part. For these reasons fixed-blade broadheads are preferred by most hunters.
The blades occasionally become damaged thereby making the broadhead unusable. Sticking a hard object such as a tree, rock or even some bones can deform the broadhead blade. Shooting a deformed broadhead can result in erratic arrow flight. Shooters may have preference for distinct blade styles depending on the conditions. Also in certain jurisdictions, particular designs are prohibited.
Therefore, a broadhead having replaceable blades is desired.
The invention comprises, in one form thereof, a broadhead having removable blades. The removable blades fit into a series of recessed portion found in the broadhead body and are locked into place with a locking device such as a lock washer. The locking device is held between the tip and the arrow shaft. The inner diameter of the locking device retains the removable blades to the body.
More particularly, the invention includes a broadhead having a body with an axis, a threaded portion and a blade recess; a tip at a first end of the body; at least two removable blades having a cutting edge, a base and a blade lock, the base being fashioned to fit within the blade recess; and a lock washer having an inner bore sufficient to slide over the threaded portion and the base positioned in the blade recess to affix the removable blades to the body.
The invention includes many optional components listed in this paragraph. For example, the body may contain a washer stop to limit travel of the lock washer. Additionally, the blade recess may extend from the threaded portion and through the washer stop. Optionally, the tip has at least two tip blades that terminate at a common point. The tip blades may make a smooth transition to the removable blades. The tip may be removable or may be integrated into the housing body. A large portion of the total mass of the removable blades is located behind the rear portion of the lock washer, that is the end away from the tip. This may be at least 50% of the total mass of the removable blade and may also be at least 75% of the total mass. Optionally, the removable blades have a relatively steep angle and may be between 25 and 50 degrees relative to the axis of the body; in one embodiment the angle may also be more narrowly defined between 32 and 43 degrees. The removable blades may also contain a rear edge extending from the end of the cutting edge to a blade opening, the blade opening allowing the locking device to travel between the base and the cutting edge. The rear edge may extend substantially orthogonal to the axis of the body. The broadhead may have 2, 3, 4, 5 or 6 removable blades with 3 removable blades being the most common configuration. Optionally, when placing the removable blades into the blade recess, the blade lock on the removable blade aligns with the washer stop on the body to form a continuous edge along the circumference of the body.
The broadhead has a short overall length. This better aligns the concentricity ferrule axis with the shaft axis. The shorter length improves arrow flight and reduces the arrow fletching profile.
In another form, the invention includes a removable blade having a cutting edge with a blade angle; a base and a blade opening beginning at the end of the base and extending to a blade lock. Optionally, the removable blade may contain any of the features discussed above.
In yet another form, the invention includes a broadhead body having an axis with a first and second end; a treaded portion at the first end; a blade recess for receiving removable broadhead blades and a washer stop to limit travel of a locking device. Optionally, the broadhead body may contain any of the features discussed above.
In another form, the invention includes a method for assembling a broadhead. The method comprises the steps of providing a body having an axis, a threaded portion and a blade recess; inserting at least two removable blades comprising a cutting edge, a base and a blade lock, into the blade recess; and securing a lock washer over the threaded portion and the base positioned in the blade recess to affix the removable blades to the body.
An advantage of the present invention is that the blades are easily removable.
A further advantage of the present invention is that the by positioning more mass away from the tip, the arrow flight is more predictable.
An even further advantage of the present invention is that a shorter overall length of the broadhead allows the arrow flight to be similar to a field or practice point.
The present invention is disclosed with reference to the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate several embodiments of the invention but should not be construed as limiting the scope of the invention in any manner.
Referring to FIGS. 1 and 2A-2D, there is shown a broadhead according to one embodiment. The broadhead 100 includes a body 110, a tip 120, removable blades 130, and a lock washer 140.
The broadhead body 110 has a threaded portion 111 proximate the rear end of the body 110. The threaded portion 111 threads into an arrow shaft to attach the broadhead to the arrow. The broadhead body may be made from any suitable material such as, but not limited to stainless steel, carbon steel, aluminum, metals, ceramics and alloys.
The broadhead body further contains a number of blade recesses 112. Generally the number of blade recesses corresponds to the number of blades attached to the body. However, it is understood that the body may contain more recesses to accommodate a wider variety of blade choices. For example, the body may contain six blade recesses but the user may only insert three blades into the body. Most common the broadhead body has between two and six blade recesses. In one embodiment, the body 110 has three blade recesses 112.
The blade recesses 112 extend parallel along the axis of the body 110. In one embodiment, the blade recess extends into the threaded portion 111 to allow a portion of the removable blade 120 to extend into the arrow shaft (not shown). This provides additional rigidity to the blade upon impact. Thereby decreasing the likelihood of a blade becoming detached.
In embodiments where a tip 120 is integrated with the body 110, the body 110 further contains a washer stop 113. The washer stop 113 limits travel of a locking mechanism such as a lock washer 140. In one embodiment, the blade recesses 112 extend through the washer stop 113, and they may even extend into the tip.
The tip 120 has a point 121 with a number of tip blades 122 extending from the point towards the rear of the tip 120. Preferably, the tip 120 is integrated with the body 110 as a single component. However, it is understood that a removable tip may be used to allow further customization by the end user. The tip blades 122 terminate and form a rear seat 123. When inserted, the leading edge 136 of the removable blade 130 abuts the rear seat 123 to form a continuous cutting surface from the point 121 to the trailing edge 137. Preferably, the number of tip blades 122 correlates with the number of removable blades 130. In one embodiment, the tip 120 has three tip blades 122. Optionally, the tip 120 further contains depressions 124 or other design features to improve the flight characteristics or aesthetic properties of the broadhead.
The removable blades 130 contain a sharpened cutting edge 131 having a leading edge 136 and a trailing edge 137. The blade base 132 is inserted into the blade recess 112 such that the top portion of the blade base 132 remains flush with the body 110. The blade opening 133 proves a gap between the cutting surface 131 and the blade base 132. Once inserted, the inner bore 141 of the lock washer 140 slides over the blade base 132 into the blade opening 133. The front portion 142 of the lock washer 140 abuts the blade lock 134 of the removable blade 130 and the washer stop 113 of the body 110 to affix the removable blade 130 to the body 110. In one embodiment, the washer stop 113 and the blade lock 134 form a continues edge along the circumference of the body 110. The blade base 132 rests inside of the arrow shaft further securing the removable blade 130. In one embodiment, the blade base is at least 3/32″ long; in another embodiment, the blade base is at least ⅛″ long; in yet another embodiment, the blade base is at least ¼″ long; and in a further embodiment, the blade base extends rearward beyond the plane defined by the trailing edge of the removable blade.
To improve flight characteristics of the arrow, the center of mass for the removable blade 130 is moved behind the blade lock 134 towards the trailing edge 137. This provides an aerodynamic advantage and less wobble during arrow flight. Normal broad head changes the overall effective length of the arrow shaft bringing more mass “front of center.” The shorter broadhead more closely represents the trajectory of field or practice points and further reduces concentricity tolerance. When assembled to an arrow shaft, the cutting edge 131 overhangs the arrow shaft (not show). In one embodiment, at least 50% of the removable blade's 130 mass is located behind the rear portion 143 of the lock washer 140 when assembled. In another embodiment, at least 70% of the removable blade's 130 mass is located behind the rear portion 143 of the lock washer 140 when assembled.
Optionally, the removable blade 130 further contains a rear edge 135. In one embodiment, the rear edge 135 is sharpened to a form a cutting surface. The rear cutting surface makes it easier to remove the broadhead by cutting through any obstructions. Alternatively, the rear edge 135 may be a smooth surface or contain a barbed design.
When affixed to the body 110, the removable blades 130 provide a continuous cutting surface from the point 121 along the tip blade 122 and the cutting edge 131 to the trailing edge 137. In one embodiment, taking the cutting surface from the point 121 to the trailing edge 137, the cutting surface has an angle between 25 and 50 degrees relative to the center axis of the body 110. In another embodiment, the cutting surface has an angle between 30 and 45 degrees relative to the center axis of the body 110. In further embodiment, the cutting surface has an angle between 35 and 40 degrees relative to the center axis of the body 110. The cutting surface may be linear from the point 121 to the trailing edge 137 or it may be slightly curved.
As discussed above, the lock washer 140 affixes the removable blades 130 to the body 110. The front portion 142 abuts the blade lock 134 and when the body 110 is screwed into an arrow shaft (not shown), the arrow shaft presses against the rear portion 143 of the lock washer 140. The lock washer 140 is effectively positioned between the blade lock 134 and the end of the arrow shaft (not shown) to prevent movement. It is understood that although a lock washer is described herein, that other suitable locking devices are envisioned. For example, the threaded portion on the body may extend to the washer stop to allow for the connection of a threaded nut. Furthermore, the locking device may be shaped to correlate with the washer stop of the arrow shaft to provide a more reliable fit.
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In use, the broadhead may take on various shapes and sizes depending on the application. In one embodiment, the circumference of the broadhead measured along the circle formed by the trailing edge 137 of the removable blades 130 as shown in
While the invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention. For example, while a three blade design is shown in the
Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/419,514 filed Dec. 3, 2010, the specification of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61419514 | Dec 2010 | US |
