Abstract:
A coupler for mounting a vibration damper to a limb of an archery bow, including a solid body having an attachment groove provided in a bottom portion of the body, which has a cross sectional shape for engaging with a projecting portion of a limb retainer, and a coupling hole provided in the top portion of the solid body to which the vibration damper is attached.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to coupler for mounting vibration dampers to an archery bow and particularly to mounting vibration dampers to limbs of an archery bow. 
     2. Prior Art 
     It is inherent in the operation of an archery bow that when the arrow is launched from the bow, a substantial amount of vibration is generated. This is apparent in both traditional bows such as recurves and in compound bows, though it is more pronounced in compound bows since the amount of energy transferred is greater. 
     This vibration generated when an arrow is launched from the bow is undesirable for several reasons. Firstly, the vibration gives a strange feeling to the holder of the bow when the arrow is launched. Secondly and more importantly, the vibration has a deleterious effect upon the arrow flight. 
     Since a significant portion of this vibration is generated by the action of the limbs of the archery bow, means have been developed which mount onto the limbs themselves which absorb or reduce the amount of vibration. However, these means for absorbing the vibration from the limbs have certain disadvantages. In particular, such means are attached to the limbs by an adhesive. This adhesive is subject to failure with the result that the vibration absorbing means will be thrown off of the limb. If this should occur, this has a very deleterious effect upon the performance of the bow and may result in a broken limb. Still further, the chances of this occurring increases with limb speed. Accordingly, with the high performance bows with more and more limb and arrow speed, it is more likely that such vibration absorbing means will fail. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a general object of the present invention to provide a means for overcoming the disadvantages of the prior art. 
     In particular, it is an object of the present invention to provide a coupler which easily and economically allows for a strong mechanical connection to be made between the vibration damper and the limb of the archery bow. 
     In keeping with the principles of the present invention, the objects are accomplished by providing a unique coupler for mounting the vibration damper to the limbs of the archery bow. This coupler generally comprises a body having two sides, a means for mounting the body to the limb of the archery bow and a means for coupling the vibration damper to the body provided on the other side of the body. Typically the means for mounting the body to the limb would comprise a slot provided in the body which has a cross-sectional shape approximating the cross-sectional shape of the part of the bow which retains limb on the riser of the bow. The means for coupling the vibration damper to the body would typically comprise a threaded hole into which the vibration damper can be screwed into. Still further and for the purposes of stability of the limbs, it is preferable that the body be conical in shape with the widest portion of the conical shape engaging the limb. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-mentioned features and objects of the present invention will become more apparent with reference to the following description taken together with the accompanying drawings wherein like reference numerals denote like elements and in which: 
     FIG. 1 is a perspective view of a compound archery bow utilizing the couplers of the present invention to mount vibration dampers to the limbs; 
     FIG. 2 is an enlarged view of a portion of FIG. 1 showing the attachment of the coupler to the limb and a vibration damper provided on the coupler; 
     FIG. 3 is a cross-sectional view along the line  3 — 3  in FIG. 2 showing the construction of a first embodiment of the present invention; 
     FIG. 4 is a bottom view of the coupler of FIG. 3; 
     FIGS. 5A,  5 B and  5 C are, respectively, side cross-sectional views and a bottom view of a second embodiment of the coupler in accordance with the teachings of the present invention; and 
     FIGS. 6A and 6B are cross-sectional views of a third embodiment of a coupler in accordance with the teachings of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, shown therein, particularly in FIG. 1, is a compound archery bow  2  having couplers  4  in accordance with the teachings of the present invention for coupling vibration dampers  6  to the limbs  8  of the compound bow  2 . The vibration damping means  6  can be further provided with weights  10  for not only assisting in the absorption of the vibration but also for setting the balance of the bow  2 . The limbs  8  are further connected to the riser portion  12  of the compound bow  2  at the limb pockets  14 . 
     Referring now to FIGS. 3 and 4, FIG. 3 shows the first embodiment of a coupler in accordance with the teachings of the present invention in cross-section and further illustrates how the coupler  4  connects the vibration damper  6  to the limb  8 . As seen in FIG. 3, the coupler  4  is provided with a conical shaped groove  16 . This conical shape groove  16  substantially extends across to the central axis of the coupler  4  as is shown in FIG.  4 . The conical cross-section of the groove  16  is a shape which approximates the cross-sectional shape of the head portion  18  of the limb retaining bolt  20 . 
     As can be clearly seen in FIG. 3, the limb retaining bolt  20  extends through a hole or slot  22  provided in the limb  8  and is threaded into a threaded hole  24  provided in the limb pocket  14  of the riser  12 . 
     In use, the limb retaining bolt  20  is unscrewed to expose a sufficient amount of the head portion  18  so that the conical slot  16  can slide over and under the head  18  of the limb retaining bolt  20 . A driving tool such as an alien wrench can then be engaged with the hexagonal shaped adjustment hole  26  provided in the top portion of the head  18  of the limb retaining bolt  20  by inserting the tool through the threaded hole  28  provided in the coupler  4 . This allen wrench is inserted through the hole  28  before the vibration damper  6  is connected thereto. By means of the alien wrench the limb retaining bolt  20  is tightened until the limb  8  is securely attached to the limb pocket  14  and the draw weight of the bow  2  is set to the desired amount. 
     A vibration damper  6  is then connected to the coupler  4 . This connection is accomplished by means of a threaded shaft  30  which is molded into the vibration damper  6  which itself is made from a vibration absorbing material such as rubber. A typical example of a vibration damper  6  is a DOINKER made by Leven Industries. 
     Accordingly, utilizing the coupler  4 , the vibration damper  6  can be reliably mechanically connected to the limb  8  of the bow  2  and the chances of the vibration damper  6  becoming disconnected from the limbs  8  is drastically reduced and is very little if properly maintained. 
     Referring to FIGS. 5A,  5 B and  5 C, show therein are cross-sectional views and a bottom view of a second embodiment of a coupler  4 ′ in accordance with the teachings of the present invention. This second embodiment of the coupler  4 ′ of the present invention is provided in two portions  30  and  32  instead of the single part of FIG.  3 . The lower portion  32  is provided with a groove  16 ′ which is substantially the same in cross-section and shape and function as the groove  16  of the coupler  4  of the first embodiment. The lower portion  32  is further provided with three threaded holes  34  which are spaced at equal intervals around the lower portion  2 . It would be equally feasible to provide four holes except that the utilization of four holes will increase the cost and complexity without increasing the functionality and reliability of the coupler. The upper portion  30  is provided with a threaded hole  28 ′ which is substantially the same as the threaded hole  28  provided in the coupler  4  of FIG.  3  and the first embodiment. This threaded hole  28 ′ is for the attachment of the vibration damper  6 . The upper portion  30  is further provided with three unthreaded holes  34 ′ which correspond to the threaded holes  34  provided in the lower portion  32 . 
     In use, the lower portion  32  is inserted onto the head portion  18  of the limb retaining bolt  20  in substantially the same way as the first embodiment. The limb retaining bolt  20  is then tightened to securely hold the bottom portion  32  of the coupler  4 ′ to the limb  8  and the limb pocket  14  of the riser  12 . After the lower portion  32  is securely fastened to the limb  8  by means of the limb retaining bolt  20 , the upper portion  34 ′ is connected to the lower portion  32  by means of screws (not shown) which are inserted through the holes  34 ′ of the upper portion  30  and screwed into the threaded holes  34  in the lower portion  32 . In a similar manner as the first embodiment, the vibration damper  6  is screwed into the threaded hole  28 ′ by means of the threaded shaft  30  which is molded into the vibration damper  6 . 
     Referring to FIGS. 6A and 6B, shown therein is a cross-section of a third embodiment of a coupler  4 ″ in accordance with the teachings of the present invention. Similarly to the second embodiment, this third embodiment is provided in upper and lower portions  40  and  42 . The lower portion  42  is provided with a groove  16 ″ which is substantially the same in cross-section and shape and function as the groove  18  provided in the coupler  4  of the first embodiment. The lower portion  42  is made in a cylindrical shape and the circumferential surface is provided with an outer threaded portion  44 . The upper portion  40  is provided with a hole  28 ″ which is substantially the same as the hole  28  provided in a coupler  4  of the first embodiment. The lower surface of the upper portion  40  is further provided with a cylindrically shaped recess  46 . The cylindrical shape recess  46  is substantially the same in diameter and shape as the cylindrical shape bottom portion  42  and is further provided with an interior thread  48 . In practice, it would also be possible to reverse the placement of the threads  44  and  48  on the upper and lower portions  40  and  42 . 
     In use, the groove  16 ″ of the lower portion  42  is inserted onto the head  18  of the limb retaining bolt  20  in substantially the same way as in the first embodiment. The limb retaining bolt  20  is then tightened to securely fasten the bottom portion  42  of the coupler  4 ″ to the limb  8  and limb pocket  14  of the riser  12  of the compound bow  2 . The inner threads  48  of the upper portion  40  are then screwed onto the outer threads  44  of the lower portion  42  and the upper portion  40  is tightened onto the lower portion  42 . The vibration damper  6  is connected to the upper portion  40  of the coupler  4 ″ by screwing the threaded shaft  30  into the threaded hole  28 ″. 
     It should be apparent to those skilled in the art that each one of the first, second and third embodiments of the present invention functions in substantially the same way once it is installed on the limb  8  of the bow  2  and provides a reliable and stable connection to the limbs  8  of an archery bow  2 . Still further, it should be apparent to those skilled in the art that the shape of the couplers in the first, second and third embodiments can be almost any solid shape such as a cone, a cube or a cylinder though a truncated conical shape is preferred. Also, while the size of the couplers of the first, second and third embodiments can be any size which is compatible with the size of the limbs  8  of the bow  2 , typically the couplers are approximately 1.25 inches in diameter at the base, 0.75 inches in height and 0.75 inches across the top of the truncated conical shape. Still further, the threaded hole  28  is typically a {fraction (5/16)}×24. Also, the coupler of the first, second and third embodiments can be made from any material which is strong enough to resist the stresses and strains of the bow  2  and could be made from a metal such as aluminum or a very hard and strong plastic such as nylon or bakelite. 
     It should be apparent to those skilled in the art that the above-described embodiments are merely illustrative of a few of the embodiments which could be created without departing from the spirit and scope of the present invention.