Abstract:
An apparatus and method for reducing stress in a bow limb of an archery bow connected to a handle/riser of the bow by allowing a butt end of the bow limb connected to a forward end of the handle/riser by a limb bolt to flex forwardly when the bow is drawn and/or allowing the bow to flex rearwardly at the rearward end of the handle/riser when the bow is drawn.

Description:
CROSS-REFERENCE TO RELATED INVENTIONS 
       [0001]    This application is a Continuation of U.S. patent application Ser. No. 11/941918 filed, Nov. 16, 2007, which claims the benefit of U.S. Provisional Application No. 60/859,395, filed Nov. 16, 2006, the entire disclosures of which are hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to archery bows. More particularly, this invention relates to an apparatus and method for mounting a bow limb to the riser of a bow handle. 
         [0004]    2. Description of the Background Art 
         [0005]    Presently there exist many different ways for mounting the upper and lower bow limbs of a compound bow to the upper and lower ends of a riser of the bow handle. Most commonly, the butt of each bow limb is positioned into a rectilinear limb pocket aligned contiguous with the outer planar surface of the bow handle riser. The butt of the limb is then affixed to the riser by a limb bolt inserted through a hole in the butt of the bow limb, through a corresponding hole in the limb pocket and then threaded into a threaded hole in the forward most end of the outer planar surface of the riser. During drawing of the bow, the bow limb pivots against the rearward edge of the limb pocket. Typically, the draw weight of the bow may be slightly reduced by unthreading the limb bolt a slight distance to decrease the distance between the tips of the upper and lower bow limbs. 
         [0006]    Unfortunately, the pivoting of the limb against the rearward edge of the limb pocket during drawing of the bow, imparts great stress to the bow limb at the pivot point. Premature failure of the bow limb therefore often occurs at such pivot point. 
         [0007]    Further, it is noted that the “middle” portion of the bow limb between such pivot point and the limb bolt seeks to bow outwardly during the drawing of the bow. 
         [0008]    However, the limb bolt precludes the forward most butt of the bow limb from flexing to follow the natural outward flexing of the middle portion of the bow limb between such pivot point and the limb bolt. Hence, considerable stress is imparted to the forward most butt of the bow limb due to the fact that limb bolt rigidly secures the butt of the bow limb to the riser. 
         [0009]    Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the archery art. 
         [0010]    Another object of this invention is to provide a limb mounting system for a compound bow that reduces the stress imparted to a bow limb that pivots against the rearward edge of the handle riser drawing of the bow. 
         [0011]    Another object of this invention is to provide a limb mounting system for a compound bow that includes a pivotable bow limb fulcrum at the rearward edge of the handle riser during drawing of the bow. 
         [0012]    Another object of this invention is to provide a positive positioning system for connecting a bow limb to a handle riser that allows the forward most butt of the bow limb to flex and follow the natural outward flexing of the middle portion of the bow limb between such pivot point and the limb bolt during drawing of the bow. 
         [0013]    Another object of this invention is to provide a positive mounting system for connecting the butt of a bow limb to a handle riser including complementary limb bolt head, swivel washer and limb cap that allow the butt of the bow limb to swivel during the drawing of the bow. 
         [0014]    The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. 
       SUMMARY OF THE INVENTION 
       [0015]    For the purpose of summarizing the invention, the invention comprises a limb mounting system including ( 1 ) a bow limb positive positioning system and ( 2 ) a bow limb fulcrum system. 
         [0016]    The bow limb positive positioning system of the invention connects a bow limb to a handle riser while allowing the forward most butt of the bow limb to flex and follow the natural outward flexing of the middle portion of the bow limb between such pivot point and the limb bolt during drawing of the bow when the bow is drawn. The positive mounting system comprises complementary limb bolt head, swivel washer and limb cap that allow the butt of the bow limb to swivel during the drawing of the bow to allow the butt to follow the natural outward flexing of the middle portion of the bow limb between such pivot point and the limb bolt during drawing of the bow, thereby reducing the stress that would otherwise be imparted to the butt during drawing of the bow. 
         [0017]    The bow limb fulcrum system of the invention is positioned at the rearward edge of the handle riser to reduce the stress imparted to a bow limb that pivots against the rearward edge of the handle riser during drawing of the bow. 
         [0018]    The functionality of the bow limb positive positioning system and the bow limb fulcrum system of the limb mounting system of the invention work alone and in unison to significantly reduce the stresses that are imparted to the forward portion of the bow limb when the bow is at rest (when undrawn) as well as when drawn. 
         [0019]    The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which: 
           [0021]      FIG. 1  is a side elevation of a single cam bow; 
           [0022]      FIG. 2  is a rear elevation of the bow from the shooter&#39;s perspective; 
           [0023]      FIG. 3  is a ¾ view of the upper half of the bow; 
           [0024]      FIG. 4  is a side elevation of the bow with the various components of the upper limb mounting system exploded for identification; 
           [0025]      FIG. 5  is a ¾ exploded view of the limb mounting system; 
           [0026]      FIG. 6  is an enlarged ¾ exploded view of the components of the limb mounting system; 
           [0027]      FIG. 7  is an enlarged ¾ view of the butt end of the bow limb and the limb cap; 
           [0028]      FIG. 8  is a ¾ top down view showing the various components of the limb fulcrum system; 
           [0029]      FIG. 8A  is a cross-sectional view of  FIG. 8  along lines  8 A- 8 A showing the outward (i.e., convex) at-rest curve of the pad when uncompressed; 
           [0030]      FIG. 9  is a ¾ bottom up view of the limb fulcrum and its components; and 
           [0031]      FIGS. 10A and 10B  are a partial longitudinal cross-sectional views of the limb showing the cross-section of the limb mounting system when the bow is in undrawn and drawn states, respectively. 
       
    
    
       [0032]    Similar reference characters refer to similar parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0033]      FIG. 1  shows the general configuration of a compound bow  1  with the handle/riser  2  and grip  3 . The handle/riser  2  is connected to the bow limbs  10  by the limb mounting system of the invention including a limb cap  50  and a limb fulcrum  20 . At the outer end of the limbs  10  is the compounding system comprising a dual feed out single take up cam  4  mounted on the bottom limb  10  and the idler wheel  5  on the top limb  10 . These two components are interconnected by the harness system comprising the bowstring  80   a  and secondary payout  80   b  and the power cable  85 . Without departing from the spirit and scope of this invention, the present invention may be applied to other bow configurations such as dual cam bows, cam and a half bows etc. 
         [0034]    The bow limb positive positioning system of the bow limb mounting system of the present invention, as shown in general in  FIG. 4  and  FIG. 5 , comprises a limb bolt  30  positioned in a snug fit into a swivel washer  40  which in turn spherically fit into the top of the limb cap  50  and the limb cap  50  is a locational fit to the limb but  18 . The butt end  18  of the limb  10  is fastened to the handle  2  with the lower surface  13  of the limb resting in limb fulcrum  20  and the limb fulcrum  20  in turn is pivotally located at the rearward end of the handle/riser  2 . 
         [0035]    As shown in  FIGS. 6 and 10 , the head of the limb bolt  30  has a tapered surface  32  which is a mating fit with the upper impression  42  in the swivel washer  40 . The lower surface  44  of the swivel washer  40  matches the spherical surface  52  in the top of the limb cap  50 . The fit between the limb cap  50  and the bow limb  10  is best shown in  FIG. 7  in which the underside of the limb cap  50  is closely fitted to the bow limb  10  such that surface  54  on the limb cap  50  is coincident with the top surface of the limb  14  and vertical surface  58  of the limb cap  50  matches the vertical surface  18  at the limb butt  18  with the vertical surface  56  of the limb cup fitting closely to the vertical surface  16  at the butt  30  of the limb  10 . The result is a positive connection between the bow limb  10  and the handle  2  at the butt  30  of the bow limb  10 . It should also be noted that the body surface  34  of the limb bolt  30  is a close tolerance fit with the counter bore  7  ( FIG. 5 ) in the bow handle/riser  2 . 
         [0036]    The bow limb fulcrum system of the bow limb mounting system of the present invention provides a limb connection to the handle/riser  2  thru a limb fulcrum  20 . As best seen in  FIGS. 8-10 , the various components of the bow limb fulcrum system comprise a rectangular limb pad  24  having surface  24   a  securely fitted into a matching pocket  20   a  of the fulcrum  20 . Bow limb surface  13  in turn rests against the upper surface  24   b  of the limb pad  24 . The edges of the bow limb  12   b  are located closely with the inside of upper vertical surfaces  21   a  of the fulcrum  20  which prevents any lateral movement of the bow limb  10  with respect to the fulcrum  20 . As shown in  FIG. 8   a , limb pad  24  is preferably manufactured to be slightly bowed outwardly (convex-shaped) when in its relaxed state such that when under compression by the bow limb  10  after assembly, it lies flat in the pocket  20   a  (see  FIG. 8 ). 
         [0037]    The limb fulcrum  20  is also fitted with a pivot plate  26  with the upper surface of the pivot  26   b  a mating fit with the pivot surface  20   b  of the limb fulcrum  20 . The lower surface of the pivot plate at  26   a  is fitted to the upper surface  6  of handle/riser  2  and the inside edge surfaces  22   a  of the fulcrum  20  are mated to the sides of the bow handle/riser  2  at surface  8  on either side of the handle/riser  2 . This arrangement allows the bow limb  10  to pivot in the plane of the bow string  80   a  while maintaining the lateral position of the bow  10  to insure that it also stays in plane. 
         [0038]    As shown in  10 B, as the bow  1  is drawn, the middle portion of the bow limb  10  tends to bow outwardly pivoting forwardly (clockwise in  FIG. 10B ) on the fulcrum  20  as shown by arrow A and pivoting rearwardly (counter-clockwise in  FIG. 10B ) on the limb cap  50  as shown by arrow B (by virtue of the swivel washer  40  spherically floating between the tapered surface  32  of the bolt head and the cap  50 ), thereby significantly reducing the stresses that would otherwise be imparted to the bow limb  10 . 
         [0039]    The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. 
         [0040]    Now that the invention has been described,