Abstract:
A modular, adjustable weight arrow tip is disclosed. The arrow tip has a body and one or more blades in various configurations. The arrow tip utilizes one more modular weights, preferably seated between the body rear end and the arrow shaft, to allow the user to be able to selectably adjust an incrementally stepped array of weights to achieve the desired flight and “front of center” for their application. The modular weights can be threaded or unthreaded, can utilize a modular weight seating collar, can have varying weights, and may be utilized with any type of archery tip.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of, and therefore claims priority to and the benefit of, U.S. patent application Ser. No. 14/170,815, now U.S. Pat. No. 9,097,500 filed on Feb. 3, 2014 and titled “Modular Adjustable Weight Arrow Tip.” 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to the field of archery arrow tips and archery arrow shafts, and more particularly to a modular, adjustable weight arrow tip and shaft. 
     BACKGROUND 
     Target archers and archers who bowhunt utilize different arrow tips (or “points”), but both wish to modify and tune the arrow, arrow tips, arrow weight, and arrow “front of center” to achieve perfect arrow flight. Most arrow shafts have a threaded insert at one end and are designed to receive an arrow tip. Two commonly used arrow tips are field tips and broadheads. Target archers commonly use field tips, which often consist of a rounded or conical point similar in shape to a bullet, with a threaded portion that secures it to the arrow shaft via a threaded insert. Bowhunters commonly utilize broadheads for hunting, which will often have two or more blades. There are many different kinds of broadheads known in the industry, including fixed blade broadheads and mechanical broadheads. Some broadheads include 2 opposing blades, while others utilize three or more blades. Many broadheads use straight edged blades, while others are curved. Additional, specialized arrow tips exist for turkey hunting, rabbit hunting, and other small game, for example “judo” points. Most all arrow tips have a threaded portion (or “stud”) adapted to be threaded into the threaded insert placed in the arrow shaft. This thread and insert system allows for archers and bowhunters to change arrow tips easily and quickly by merely unscrewing one tip and screwing in another. 
     Archers and bowhunters desire to control the aerodynamic properties and hunting properties of the arrow by selecting different weights of arrow tips. However, arrow tips with different weights, or even different shapes, will have different flight characteristics. For example, one field point may weigh 100 grains, while another field point may weigh 125 grains, and yet another may weigh 150 grains. All three different field points will have different flight characteristics. 
     Similarly, different broadhead arrow tips may have different weights, ranging from below 100 grains, to some specialty arrow tips weighing in at over 200 grains. The larger hunting arrow tips may be desired by a hunter for larger blades or more overall weight to produce more force upon impact. 
     At present, if an archer or bowhunter wishes to change the performance of their arrow via experimenting with different weighted arrow tips at the end of the arrow, they are generally required to purchase many different weighted field points or broadheads in order to test them and determine which performs best for the length of their arrow, spine of the arrow shaft and poundage of the bow they are shooting. Additionally, an archer may sight in their bow using field points that weigh 100 grains, but then later purchase broadheads or other hunting arrows tips that weigh 125 grains. In that instance, the archer may have to re-sight in their bow using 125 grain field points, or using the broadheads themselves. 
     Different arrows may have different spine flex, e.g., have different stiffness. In fact, a particular arrow manufacturer may have multiple arrow models/types having different spine flex, each different spine flex being optimized for different bows and different bow draw weights and lengths. If a weak arrow having too much flex is shot, it will have an undesirable amount of flex, and its flight trajectory may not be true. A stiffer arrow, on the other hand, will have less oscillation, or flex, when shot, will correct more quickly from the force of the bow, and have a better flight trajectory. Similarly, a shorter arrow will ordinarily have less spine flex than a longer arrow of the same type. However, having the right amount of weight at the front end of the arrow, for example, in the tip, can optimize the overall flex and trajectory. By adjusting the overall weight at the tip, a user can adjust how the spine reacts. Unfortunately, this normally requires the user to experiment with different tips, having different weights, to determine what works best for their bow, draw weight, draw length, arrow length, etc. 
     There are some prior art patents for arrow tips that incorporate limited aspect of adjustable weights, but such prior art patents are not user friendly, require specialized tools, and do not maximize the weight distribution and spine flex of the arrow shafts. Moreover, some of the prior art patents can even be dangerous to use. For example, U.S. Pat. No. 7,318,783 B2 discloses the use of one or more washers and weights to an arrow insert and arrow point in a location forward of the junction between the arrow shaft and the arrow tip, and located within a cavity formed by the broadhead blades. Adding weights to a threaded stub located between multiple sharp blades can obviously be dangerous. U.S. Pat. No. 5,269,534, discloses weights applied to the arrow shaft itself, behind the insert that accepts the arrow tip, and uses a horizontal bar to add and remove weights, actually adjusting the weight of the arrow, not the weight of the arrow tip. Special tools and/or systems are required to adjust the weights in these systems and they require extensive steps to accomplish change. 
     SUMMARY OF THE DISCLOSURE 
     The present invention will solve the archer&#39;s dilemma of weight distribution and spine flex of arrow shafts during flight and ultimately at the point of impact. The Modular Weight System (hereafter M.W.S.) will allow the individual archer to easily experiment with various front weights to enhance the flight of the arrow by adjusting the front load or “Front of Center” of the arrow. The M.W.S. is unique in that there is no known other system available that will allow such versatility and easy modification of the physics and physical characteristics of the arrow by adding or removing weights, particularly from the arrow shaft and arrow tip juncture. The M.W.S. will allow the archer to tune the flight of the arrow and spine characteristics of their arrow, preferably by inserting various modules, or modular weights, in between the end of the arrow shaft and the back of the arrow tip. The system has application to all arrows, crossbow bolts, bow fishing arrows, and the like, and associated tips, regardless of material, size or blade configuration. It can be used with all types of broadheads and hunting tips, including fixed blade and mechanical broadheads, field tips, etc. 
     Designed to allow the user to apply various weights, the M.W.S. allows the user to increase or decrease the weight of the arrow, and particularly at the arrow tip/arrow shaft junction, by adding or deducting weight modules. The user will be able to selectably adjust an incrementally stepped array of weights to achieve the desired flight and “front of center” for their application. 
     One object of the present invention is to provide a modular, adjustable weight arrow tip that is easy to use, and does not require special tools. 
     Another object of the invention is to provide an adjustable weight arrow tip that can be easily adjusted by adding or removing weights at the junction of the arrow tip and arrow shaft. These weights, or modules, can be used in conjunction with one another in a chain or stacking formation. 
     Another object of the invention is to provide an adjustable weight arrow tip that can optimize the overall flex and trajectory of an arrow. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The present invention is disclosed with reference to the accompanying drawings, wherein; 
         FIG. 1  is an side view of a prior art arrow tip, commonly referred to in this configuration as a broadhead. 
         FIG. 2  is a perspective view of one embodiment of the present invention. 
         FIG. 3A  is a side view of one embodiment of the modular adjustable weight. 
         FIG. 3B  is a top view of one embodiment of the modular adjustable weight. 
         FIG. 4  is a view of one embodiment having two modular adjustable weights stacked or “chained” together. 
     
    
    
     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. 
     DETAILED DESCRIPTION 
     For ease of reference, the following components and reference numbers are used:
           100  Arrow tip     105  Blades     106  Set screw     110  Body     111  Body front end     112  Body rear end     113  Arrow tip point     115  Shoulder     120  Modular weight shoulder     130  Modular weight seating collar     135  Arrow seating neck     140  Modular weight seating collar shoulder     145  Height of the modular weight seating collar  130 , designated as H 0       150  Threaded stud     160  Outside diameter of modular weight main body OD 1       165  Modular weight main body     170  Outside diameter of modular weight neck OD 2       175  Modular weight neck     180  Outside diameter of modular weight channel OD 3       190  Overall height of modular weight H 1        200  Height of modular weight without modular weight neck H 2        210  Height of modular weight neck H 3        300  Arrow     301  Arrow shaft opening     305  Arrow insert     310  Arrow insert threaded portion     315  Arrow insert unthreaded portion     320  Modular weight channel     500  Modular weight     510  Modular weight recessed portion       

     As discussed above, existing broadheads come in many different sizes, shapes, and configurations, including fixed blade and mechanical, among others. There are a wide number of manufacturers and brands, often with their own specialized blade designs, including broadheads sold under the trademarks Toxic, Grim Reaper, Slick Trick, Muzzy, Wasp, Magnus, RamCat, NAP, Swhacker, Rocket, Carbon Express, G5, and Trophy Ridge, to name a few. These different broadhead designs are well known to those of skill in the art, the teachings of which incorporated herein by reference. 
     Referring to  FIG. 1 , an example prior art arrow tip  100  is depicted. In the configuration shown in  FIG. 1 , the particular arrow tip  100  is more commonly referred to as a broadhead. Other arrow tips that can include and utilize the present invention include field points, bowfishing arrow tips, crossbow bolts, and other related archery products. In its basic embodiment shown in  FIG. 1 , the arrow tip  100  contains a body  110 , often cylindrical in nature, and a number of blades  105 . The body  110  will normally have a front end  111  and a rear end  112 . In  FIG. 1 , the front end  111  may have threaded arrow tip point  113  secured to the body  110 , or integrally formed as part of the body  110 . The body rear end  112  will often define a shoulder  115  that is designed to engage an arrow, and more particularly an arrow shaft, as described further below. The traditional broadhead will often have an arrow seating neck  135  and a threaded stud  150 . The length of the arrow seating neck  135  and threaded stud  150  is generally approximately ¼ inches each (for a total of approximately ½ inches), and may range from ⅜ inches to ⅝ inches in combined length. In most prior art arrow tips  100 , the length of the arrow seating neck  135  and threaded stud  150  are approximately equal. 
     Still referring to  FIG. 1 , the arrow tip  100  is configured to be inserted and secured to an arrow  300 . The arrow  300  will traditionally have a nock and fletchings on the back end (not depicted), and an arrow shaft opening  301  on the front end to receive the arrow tip  100 . The arrow  300  will normally have an arrow insert  305  placed inside the arrow shaft, and the arrow insert  305  will normally include a threaded portion  310  and a unthreaded portion  315  designed to receive the threaded stud  150  and arrow seating neck  135 , respectively, of the arrow tip  100 . The outer perimeter of the arrow opening  301  rests against the arrow tip shoulder  115  when the threaded stud  150  is screwed into the threaded portion  310  of the arrow insert  305 . Preferably, the body  110  is circular in cross section and has the same outer diameter at the body rear end  112  as the outer diameter of the arrow  300 . This provides better aerodynamic properties. 
     Depicted in  FIG. 2  (not to scale) is one embodiment of the current invention.  FIG. 2  discloses an arrow tip  100  having blades  105  and a body  110 . One or more of the blades may be secured to the body  110  using a set screw  106  that can go through the body  110  and one or more of the blades  105 . In this embodiment, the body  110  is circular in cross section, but has a varying diameter, from a smaller cross section toward the body front end  111  transitioning to a larger cross section toward the body back end  112 . The blades may be in any configuration, material, size, or shape known to those of skill in the art as discussed above. The blades  105  can be forward of the body front end  111 , as shown  FIG. 2 , or body front end  111  may have a separate sharpened point, with the blades behind the arrow tip point  113 , as shown in  FIG. 1 . In this second configuration, the arrow tip point  113  may be removable, often through a threaded connection, as in commonly known in the art. The blades  105  of the arrow tip  100  may be in a stand-alone, “fixed” configuration, e.g., the blades are secured in place even without being attached to an arrow. The blades  105  can be secured to the body using any means known in the industry, including by a set screw discussed below, a threaded arrow tip point  113  (as shown in  FIG. 1 ), collar on the trailing edge of the blades, or formed integrally with the body (e.g., not designed to be removable from the body). Alternatively, the blades  105  may only be “fixed” when the arrow tip  100  is screwed into the arrow (in this latter case, the compression against the arrow tip  100  securing the blades  105  in place). In a preferred embodiment, the body  110  is made of aluminum, and more preferably 7075 aircraft grade aluminum. Other acceptable materials known to those of skill in the art, and utilized in other existing arrow tips can be utilized, including steel and stainless steel. 
     Although many different blade configurations can be utilized, including any of the many blade configurations from the various manufacturers and brands discussed above, the arrow tip  100  in  FIG. 2  utilizes a main blade having a 1.21 inch cutting surface, and a “bleeder blade” having a 0.63 inch cutting surface, and generally in a perpendicular arrangement to the main blade. As discussed above, almost any blade configuration can be utilized, provided that appropriate changes are made to the arrow tip  100  to accommodate the modular weight discussed further below. 
     Referring to the configuration shown in  FIG. 2 , the arrow tip  100  includes a modular weight shoulder  120  at the body rear end  112 . The modular weight shoulder  120  is preferably circular in cross section, forming a planar section which is perpendicular to the longitudinal axis of the body  110 . The modular weight shoulder  120  is configured to rest against a modular weight  500 , if used, or against the arrow shaft opening  301 , if the modular weight  500  is not used. The outer diameter of the body  110  at the rear end  112  is preferably the same as the modular weight outer diameter  160  and the outer diameter of the arrow  300 . In one embodiment, the outer diameter of the body at the rear end  112  is between ¼ inches and ½ inches, although the size can vary. In a preferred embodiment, it has an outside diameter of approximately 5/16 inches. 
     Still referring to the embodiment of  FIG. 2 , the body rear end  112  may contain a modular weight seating collar  130 . In one embodiment the modular weight seating collar is circular in cross section, forming a planar section which is perpendicular to the longitudinal axis of the body  110  and threaded stud  150 , and parallel to the planar section of the modular weight shoulder  120 . At the trailing end of the modular weight seating collar  130  is a modular weight seating collar shoulder  140 , from which the threaded stud  150  extends, preferably along the same longitudinal axis of the body  110 . In one embodiment, the modular weight seating collar  130  is between ⅛ inches and ¾ inches in diameter. In a preferred embodiment, the modular weight seating collar  130  is approximately 5/16 inches in diameter. The diameter of the modular weight seating collar  130  may correspond to, or at least approximate, the outside diameter of the modular weight neck  170 , discussed further below. The modular weight seating collar  130  can be threaded or unthreaded. In a preferred embodiment, it is unthreaded. In a separate embodiment, the modular weight seating collar  130  can be the same approximate diameter as the threaded stud  150 , but be unthreaded, such that there is a single extension from the body rear end  112  (e.g., a single stud which is partially unthreaded toward the body rear end  112 , and partially threaded to be secured into the arrow insert threaded portion  310 . 
     In one embodiment, the height of the modular weight seating collar  130 , designated as H 0   145 , is between 1/16 inches and ¾ inches. Similarly, the threaded stud  150  may be between 1/16 inches and ¼ inches in diameter and between ¼ inches and 1.5 inches long. In a preferred embodiment, the threaded stud has a diameter of approximately 3/16 inches and a length of ⅝ inches. The diameter and length can be varied as necessary and desired. Unlike most conventional broadheads where there is approximately ½ unthreaded portion (arrow seating neck  135  of  FIG. 1 ) and a ½ threaded portion (threaded stud  150  of  FIG. 1 ) that extends into the arrow shaft insert  305 , one embodiment of the current invention has a ratio of unthreaded portion (the modular weigh seating collar  130 ) to threaded portion (threaded stud  150 ) of between 1:3 and 1:5 (e.g., for every ¼ inch of unthreaded portion, there is ¾ inches to 1¼ inches of threaded stud  150 ). Unlike the conventional broadheads, the current invention can contain very little or no unthreaded portions. The extra length of the threaded stud  150  can accommodate one or more modular weights  500 . 
     In alternative embodiments (not depicted), a modular weight seating collar  130  is not utilized and the threaded stud  150  is connected directly to the modular weight shoulder  120 . The modular weight  500  is depicted in dashed lines in  FIG. 2 . As can be seen in  FIG. 2 , additional portions of the threaded stud  150  remain that can be secured in the arrow shaft insert  305 . 
     Depicted in  FIG. 3A  is a side view of one embodiment of the modular weight  500 . In this embodiment, the modular weight has a main body  165 , having an outside diameter designated as OD 1   160 , and a neck  175 , having an outside diameter of OD 2   170 . In one embodiment, the modular weight  500  has a main body outside diameter  160  of between ¼ inches and ½ inches, although the size can vary. In a preferred embodiment, it has a main body outside diameter  160  of approximately 5/16 inches. In one embodiment, the modular weight neck  175  has an outside diameter  170  of between 1/16 inches and ¼ inches, although the size can vary. In a preferred embodiment, the modular weight neck  175  had an outside diameter  170  of approximately 3/16 inches. 
     In one embodiment, the overall height of the modular weight  500 , having a height designated at H 1   190 , is between ⅛ inches and ½ inches, although the size can vary. In a preferred embodiment, the overall height of the modular weight  190 , is approximately 5/16 inches. In one embodiment, the height of the main body of the modular weight, designated as H 2   200 , is between 1/16 inches and ½ inches, although the size can vary. In the preferred embodiment, the height of the main body of the modular weight  200  is 3/16 inches. In one embodiment, the height of the modular weight neck, designated as H 3   210 , is between 1/16 inches and ½ inches. In the preferred embodiment, the height of the modular weight neck  210  is approximately ⅛ inches. 
     The modular weight  500  has a channel  320  through which the threaded stud  150  may placed. The outer diameter of the channel  320 , designated as OD 3   180 , in  FIGS. 3A and 3B , may correspond to, or approximate, the diameter of the threaded stud  150 . In one embodiment, the outer diameter of the channel  180  is between 1/16 inches and ¼ inches. In a preferred embodiment, the outer diameter of the channel  180  is approximately ⅛ inches. The modular weight channel  320  can be threaded or unthreaded. In the threaded embodiment, it is secured to the arrow tip  100  by screwing it on the threaded stud  150 , and preferably seated against the modular weight shoulder  120 . The modular weights  500  can be of various size and configuration, and may not utilize the neck depicted in  FIG. 3A . For example, they can be of uniform cross section. The modular weights  500  may have different heights to accommodate different weights. Preferably the modular weight  500  is of circular cross section. 
     In another embodiment, the modular weight channel  320  of the modular weight  500  is not threaded. In this embodiment, the modular weight  500  can be secured between the modular weight shoulder  120  and the arrow  300  by compression fit using the threaded stud  150  in the threaded arrow insert threaded portion  310 . 
     In the embodiment of the arrow tip  100  using a modular weight seating collar  130 , the modular weight  500  can have a recessed portion  510  that corresponds to the size, shape, and configuration of the modular weight seating collar  130  such that the modular weight  500  can be secured such that there is no gap between the modular weight shoulder  120  and the forward facing portion of the modular weight  500 . The modular weight neck outside diameter  170  may also correspond to the outside diameter of the modular weight seating collar  130  as well as the modular weight recessed portion  510 . Similarly, the depth of the modular weight recessed portion  510  may correspond to the height of the modular weight neck  210 . This is helpful when multiple modular weights are used together. In this instance, the modular weight neck  175  of the first modular weight  500  is seated in the modular weight recessed portion  510  of the second modular weight  500 . 
     In one embodiment, the modular weight  500  is between about 10 and 100 grains in weight, although the modular weight can be of almost any weight. In one embodiment, the modular weight is made of stainless steel. In other embodiments, the modular weight is made of steel, aluminum, brass, or copper. 
     Depicted in  FIG. 4  is one embodiment of the invention of several modular adjustable weights stacked or “chained” together. This allows a user to customize the amount of weight. The extra length of the threaded stud  150  can help allow a threaded portion to remain available for securing to the arrow shaft insert  305 , despite a portion of the threaded stud  150  covered by the extra modular weights  500 . When used with an arrow, the threaded stud  150  is screwed into the arrow insert  305 , or otherwise fixed to the arrow shaft by means known to those of skill in the art. In the preferred embodiment the arrow shaft opening  301  rests against the trailing edge of the modular weight body  165 . In embodiments using a modular weight neck  175 , the neck preferably rests in the arrow insert unthreaded portion  315 . 
     In an alternative embodiment, the modular weight  500  does not have the same outside diameter as the arrow  300  and/or the rear end of arrow tip body  112 . The modular weight  500  can be made of metals, plastics, rubbers, synthetic materials, and liquids in various sizes, shapes and weights. The modular weight(s)  500  preferably reside in the junction between the arrow shaft and the body rear end  112  by means of tap and die threads, compression fit, adhesives and other means of affixing the weight to allow interchangeability and modular use. These modular weight(s)  500  can be used in conjunction with one another in a chain or stacking formation. 
     The total weight of the arrow tip  100 , including the body  110 , blades  105 , modular weight seating collar  130  (if used), and threaded stud  150  can vary based on the size and diameter of the body, blades used, blade configurations, etc. In one embodiment, the arrow tip  100  is 100 grains. In alternative embodiments, the arrow tip  100  is 125 grains, and in a third embodiment, the arrow tip is 150 grains. Obviously, the arrow tip  100  can be designed to any desired weight. The modular weight  500  can also be of various weights based on the size and diameter of the body and/or arrow  300  shaft, based on the materials used to construct the modular weight  500 , or the overall height of the modular weight. In one embodiment, the modular weight  500  is 25 grains. In alternative embodiments, the modular weight  500  is 10 grains, and in a third embodiment, the modular weight  500  is 50 grains. In another embodiment, multiple modular weights  500  of varying weights are provided such that any desired overall weight can be achieved. This allows a user to easily use and test various weight combinations with the user&#39;s particular configuration. For example, if the “base” arrow tip  100  weighs 100 grains, but the user has determined that a total weight of 125 grains provides the optimum “front of center” for the user&#39;s particular arrow and bow configuration, the user can simply add a 25 grain modular weight  500  to obtain the desired weight distribution. 
     The modular weight  500  can also be sold separate from an arrow tip  100 , and designed to be utilized with any of the various existing arrow tip designs. Moreover, the modular weight  500  could be configured to be secured into the arrow shaft (rather than to an arrow tip), for example, by having its own threaded portion and/or neck designed to engage the standard arrow insert  305  depicted in  FIG. 1 . In this embodiment, the modular weight channel  320  could be configured to receive the threaded stud  150  of an arrow tip  100 . 
     The modular weight  500  can also be configured to have a recessed portion on the trailing end that is sized to create a sleeve that goes on the outside of the arrow shaft when in use. Thus the front end of the modular weight  500  rests against the modular weight shoulder  120 , while the trailing end forms a sleeve that slides over the outer diameter of the arrow shaft. This embodiment can provide so additional structural rigidity to the front of the arrow. 
     The modular weight  500  can also incorporate small blades, spurs, or protrusions that extend out from its surface. This can provide additional cutting surfaces, help the arrow not pass through a target, and/or provide more force on impact. In such embodiment, the blades, spurs, or protrusions are preferably offset from the main blades and/or bleeder blades, to provide additional cutting surfaces. 
     Although particular embodiments of the present disclosure have been described, it is not intended that such references be construed as limitations upon the scope of this disclosure except as set forth in the claims.