Abstract:
An accessory for modifying the decay pattern of vibrations set up in an implement to which the accessory is attached, and the combination of a decay pattern modifying accessory and an implement. Methods of manufacturing decay pattern modifying accessories are also disclosed.

Description:
[0001]    This is related to U.S. Provisional Patent application Ser. No. 60/178,552, filed Jan. 26, 2000. The benefit of the filing date of that application is hereby claimed. 
     
    
     
       TECHNICAL FIELD OF THE INVENTION  
         [0002]    The present invention relates to novel accessories for archery bows and, more particularly, to such accessories which are capable of significantly reducing both bow jump and the noise made when an arrow is released.  
         BACKGROUND OF THE INVENTION  
         [0003]    U.S. patent application Ser. Nos. 09/478,921, filed Jan. 6, 2000 and 09/466,512, filed Dec. 17, 1999 disclose archery bow accessories respectively identified in the commercial world by the names LIMB SAVER™ and STRING LEECH™.  
           [0004]    A LIMB SAVER™ is an accessory that can be attached to the limbs of a bow and/or to the outer end of the stabilizer of a bow equipped with an accessory of that character to reduce the adverse effect of the vibrations set up in the bow when an arrow is released.  
           [0005]    A STRING LEECH™ is designed to reduce the noise generated when an arrow is released. Devices with this objective are known in the trade as string silencers.  
           [0006]    One type of STRING LEECH™ string silencer is knotted onto a bowstring, one at each end of the string. A second type of STRING LEECH™ is installed between two parts of a split bowstring and retained in place by complementary elements of the silencer.  
         SUMMARY OF THE INVENTION  
         [0007]    There have now been invented and disclosed herein certain new and novel archery bow accessories which are also designed to reduce the noise made when an arrow is released and, in addition, to significantly reduce bow jump caused by release of the arrow. These shock absorbing accessories are attached to the riser of the bow. They can be used alone or in combination with LIMB SAVER™ and STRING LEECH™ accessories and/or in combination with other devices designated to attenuate the adverse effect on accuracy attributable to bow jump and noise when an arrow is released.  
           [0008]    An accessory employing the principles of the present invention is attached to the riser of a bow, typically using the drilled and tapped hole provided for a conventional bow stabilizer.  
           [0009]    The novel shock absorbing accessories disclosed herein are made up of a rigid transfer rod or transfer rod assembly, a viseo-elastic shock absorbing component, and a compression ring. When an arrow is released, vibrations set up in the bow are transferred to the riser with the transfer rod (or assembly) directing vibrations from the riser to the shock absorbing component of the accessory. The shock absorbing material reduces the time for which vibrations of a character that might effect accuracy are felt by the user. Also, the shock absorbing material causes maximum energy to be transferred to the arrow being released.  
           [0010]    The shock absorbing component of the accessory is very effective, in part because it is preloaded as the accessory is assembled. The compression ring keeps the shock absorbing component in its compressed, preloaded state.  
           [0011]    Shock absorber accessories as disclosed herein work well both with double cam bows—where the entire bow tends to jump forward when an arrow is released—and single cam bows—where the bottom of the bow tends to kick forward and upward on arrow release.  
           [0012]    Accessories as disclosed herein are also relatively light, which is another significant advantage of these products.  
           [0013]    The performance of a bow equipped with an accessory as disclosed herein can be enhanced by attaching a bow stabilizer or a vibration pattern modifier of the character disclosed in co-pending application Ser. No. 09/478,921 to the accessory. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a pictorial illustration of a compound bow equipped with a shock absorbing accessory embodying the principles of the present invention and provided to reduce bow jump and noise when an arrow is released;  
         [0015]    [0015]FIG. 2 is a perspective view of the shock absorbing accessory;  
         [0016]    [0016]FIG. 3 is an exploded view of the shock absorbing accessory;  
         [0017]    [0017]FIG. 4 is a view similar to FIG. 3 but with a shock absorbing component of the accessory shown in section taken substantially along line  4 - 4  of FIG. 2;  
         [0018]    [0018]FIG. 5 is a graph showing the shock imparted to a representative compound bow when an arrow is released; and  
         [0019]    [0019]FIG. 6 shows how the shock is reduced when the bow is fitted with a shock absorbing accessory as shown in FIGS.  1 - 4 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    Referring now to the drawings, FIG. 1 depicts a compound bow  20  equipped with a vibration decay pattern modifying, shock absorber  22  embodying the principles of the present invention. Bow  20  has flexible limbs  24  and  26  mounted to the opposite ends of riser  28  and bow string  30 . The bow string is strung around cams  32  and  34  at the ends of limbs  24  and  26  with the ends of the bow string being anchored to shafts  36  and  38  which rotatably support cams  32  and  34  from the limbs  24  and  26  of bow  20 .  
         [0021]    As is best shown in FIGS.  2 - 4 , the vibration decay modifying accessory  22  has a unit  40  made up of elastomeric decay pattern modifying, elastomeric component  42  surrounded by a compression ring  44 ; a flanged tube  46  with integrated internal threads  90 , and a flanged vibration transfer component  48  with integrated, externally threaded elements  50  and  52  at its opposite ends.  
         [0022]    Referring now primarily to FIGS. 3 and 4, the elastomeric component  42  of unit  40  has a circular profile (see FIG. 2). The major elements of component  42  are a head  54  and an integral, depending stem  56  with straight and beveled conical profile elements  58  and  60 . The head  54  of component  42  has a vertical edge  63  between two, integral, tapered edges  62  and  64 . The lower part of head  54  constitutes a skirt  66  with an inner edge  68  which is concentrically spaced about the lower part of head  54  and its inner edge  70 . This leaves a gap  72  between the head  54  and stem  56  of component  54 , which allows decay pattern modifying movement of head  54  relative to stem  56 .  
         [0023]    Decay pattern modifying movement of head  54  is further promoted by concentric, inverted pyramid grooves  74  and  76  in the upper part  62  of head  54  and by pockets or recesses which are equiangularly spaced around the periphery of integral stem element  56 . These pockets, all identified by reference character  77  (see FIG. 3) for the sake of convenience, have closed inner ends and open onto the groove  72  between head and stem components  54  and  56 .  
         [0024]    The stem  56  of decay pattern modifying, elastomeric component  42  can vibrate or oscillate in directions generally normal to the longitudinal axis  78  of accessory  22  in any and all directions around the circumference of the transfer component  48 . At the same time, head  54  of the component  42  can oscillate laterally and vertically (with that component oriented as shown in FIG. 4), and the edge portion  63  can also oscillate around the circumference of the head in directions generally paralleling axis  78 .  
         [0025]    The effectiveness of accessory  22  is promoted by preloading the elastomeric component  42  of the accessory. Preloading is accomplished by first installing the elastomeric component  42  in ring  44 , which generally spans the edge element  63  of head  54 . Next, flanged component  46  is installed in a central bore  80  extending from top to bottom through elastomeric component  42  with a tubular element  82  of component  46  located in, and extending from the top to the bottom of component  42  and with a flange  84  of component  46  butting the top edge  86  of the elastomeric component  42 . Next, the externally threaded element  50  of vibration transfer component  48  is threaded into the tubular element  82  of component  46 , the external threads  88  on element  50  engaging the complimentary internal threads  90  in tubular element  82  and drawing components  46  and  48  together until the flange  92  on component  48  engages, and presses against, the bottom edge  94  of elastomeric component stem  56 , squeezing elastomeric component  42  in a vertical direction. This action generates a laterally extending force which is maintained in element  42  by the tubular element  82  of component  46  and compression ring  44 , which keep component  42  from expanding inwardly or outwardly by effective “squeezing.” 
         [0026]    The rotation of component  48  in sleeve  82  is continued until the flange  92  of component  48  engages the lower end  96  of tubular element  82 . As best shown in FIG. 4, this end  96  is spaced from the bottom  94  of elastomeric component stem  56 . The load applied to elastomeric component  42  can be provided at a selected level by adjusting this spacing.  
         [0027]    Accessory  22  is, in the illustrated, exemplary application of the invention, mounted to the riser  28  of bow  20  by threading element  52  of accessory component  48  into a drilled and tapped, blind aperture  97  in the riser until the bottom or lower edge  98  of the accessory component element  48  is seated on, and frictionally engaged with, the front edge  100  of riser  28 .  
         [0028]    [0028]FIGS. 5 and 6 compare the decay pattern of a bow such as the one illustrated in FIG. 1 without an accessory as disclosed herein (FIG. 5) with the decay pattern for the same bow equipped with an accessory of the character identified by reference character  22 . It will be apparent to the reader that accessory  22  significantly shortens the decay time of the vibrations set up in the bow when an arrow is released, especially those larger and consequently more deleterious vibrations. The result is a significant advantage. The practical result, as discussed above, is a marked reduction both in bow jump when an arrow is released and the noise generated when that action occurs.  
         [0029]    The shock absorbing elastomeric component  42  (see FIG. 4) of the present invention is preferably fabricated from a soft, viseo-elastic material with a Shore A hardness in the range of 3 to 20.  
         [0030]    One suitable viseo-elastic material is NAVCOM™. NAVCOM™ is a soft, amorphous, rubber-like material which contains a mixture of chloroprene and butyl polymers and has the following physical properties (representative).  
                                                                                   Shore A hardness: 17-90                    Ultimate   Tensile                   Shore   Elongation   Strength   Compression   Specific       Environment   A   (Percent)   (PSI)   Set (Percent)   Gravity                         7   1,075   373   6.01   1.014           12   900   643   7.3   1.025           20   835   1,069   6.9   1.063           30   1,056   1,621   4.0   1.074           40   326   1,453   N/A   1.185           90   175   2,440   N/A   1.379       Oven aged    7   N/A   N/A   56.3   —       for   12   —   —   31.1   —       70 hrs at   20   —   —   30.8   —       212 ± 5° F.   40   —   —   22.4   —           90   —   —   18.6   —                  
 
         [0031]    [0031]                                                       At room temperature - Medium           Resilience:   At high temperature - Fairly high                           Heat resistance   Good           Outdoor aging resistance:   Excellent           Low temp flexibility:   Good           Abrasion resistance:   Good           Flex life:   Good           Solvent resistance:           Hydrocarbons -   Fair to good           Oxygenated -   Fair to good           Air permeability:   Low to moderate           Moisture resistance:   Fair           Useful operating temperature:   −40° to 250° F.                        
         [0032]    While the invention is described and illustrated here in the context of a preferred embodiment, the invention may be embodied in many forms without departing from the spirit or the essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.