Abstract:
Disclosed is a device made of a soft, flexible elastomer with freely movable members for use as a vibration dampener on an archery bow limb. Upon release of an arrow from an archery bow, the damper members reactively contact and rebound against the bow limb. The device can be installed on a mount to attach to both solid limb and split limb bows at the same general location on both the top and bottom limbs to greatly reduce the duration of vibration, the amount of hand shock and perceived noise generated upon release of an arrow from an archery bow.

Description:
THE FIELD OF THE INVENTION 
       [0001]    The present invention is a device used for dampening vibrations of a bow limb after the release of an arrow from an archery bow. 
       BACKGROUND OF INVENTION 
       [0002]    Archery bows generate excessive noise when fired due to the considerable amount of vibration of the archery bow limbs. Other bow limb vibration dampeners position the greater mass of the elastomer device at the end furthest from the mount. This allows the greater mass of the device to wiggle and jiggle in free space without making contact with the bow limb. Although these devices were effective in reducing vibrations in older bows, they are not as effective when attached to newer bows that have a generally parallel limb arrangement. This is due to the unique forces placed on the bow limbs upon the release of an arrow from an archery bow. The reason that more manufactures have started using this parallel limb mounting arrangement is because it has been observed that hand shock, vibration and noise are reduced. 
         [0003]    There exist a need for more modern compound bows with parallel and non-parallel limbs to place the elastomer dampening device closer to the surface of the archery bow limb to allow symmetric and asymmetric rebounding of the device against the surface of the bow limb. It has been observed that the actions of the device upon firing an arrow from an archery bow will greatly reduce the duration of vibrations, hand shock and perceived noise in the archery bow. 
       DISCUSSION OF PRIOR ART 
       [0004]    When a high performance archery bow releases an arrow from full draw most of its stored energy is transferred to the arrow. The arrow is accelerated from full draw of the archery bow to its undrawn state, thus sending the arrow down range to its target. Due to the dynamics of a high performance archery bow not all of the stored energy is transferred to the arrow, but instead some of this energy is transferred to the limbs which impart vibrations throughout the bow causing unwanted noise and hand shock to archer&#39;s hand. 
         [0005]    Inventors over the years have developed stabilizers that mount to the riser of an archery bow by means of a threaded fastener. Some of these stabilizers incorporate dampening devices installed both internally as well as externally. Hydraulic cylinders filled with oil, with or without pistons, with or without springs on either side as well as pneumatic/oil systems were designed. Other inventions used a simple tube and filled it with gel with or without some form of a solid media suspended in the compound. Many combinations of elastomeric polymers were also used in either in a stationary device or employed in conjunction with some form of a mechanical device. While a good number of these products work well to reduce vibration as well as hand shock, they are mounted a considerable distance from the tips of the bow limbs where the dynamics of vibration are the greatest upon the release of an arrow from an archery bow. 
         [0006]    A later invention, U.S. Pat. No. 6,257,220 McPherson (2001) places vibration dampening modules inside of riser at both the top and bottom of riser beneath limb attachment bolts. This proved to help reduce some vibration and noise. U.S. Pat. No. 6,588,414 McMillian III (2003) mounted a soft polymer insert through the riser handle where the stabilizer could be threaded into an insert isolated from the riser. While these devices help reduce noise and vibration to a certain extent, these devices were still mounted a distance from the limb tips. U.S. Pat. No. 6,526,957 Leven (2003) describes the use of the device to attach a stabilizer to the end of the limb fastened to the riser with the limb bolts. This device in pairs would also help reduce vibration to an extent, but would make the bow more cumbersome in the field as well as increase the overall weight of the bow. 
         [0007]    Another patent for vibration dampening devices used for sporting good implements and hand tools, U.S. Pat. No. 5,362,046 Sims (1994). This patent is restricted for use with “implements”, as defined in Sims patent, “wielded devices designed to impart and receive impacts including but not limited to: golf clubs, baseball and softball bats, tennis rackets, and hammers.” Later U.S. Pat. No. 5,772,541 Buiatti (1998) describes the invention as being used on hand held implements such as ball bats, golf clubs, and for the first time archery bow limbs from claim  12 . 
         [0008]    Due to the development in recent years of lower durometer elastomeric polymers with relatively higher tensile strengths, there have been several vibration damper inventions made that install on an archery bow string. U.S. Pat. No. 6,237,584 Sims (2001) known to the archery industry as “Leaches” and U.S. Pat. No. 6,761,158 Wright (2004) a prior art of the inventor known to the archery industry as “BowJax” were a few of the devices designed to reduce string vibration and noise known to an archer as “string twang”. These devices also worked to reduce the overall sound of the bow, but had little affect on limb vibration and hand shock. 
         [0009]    Later U.S. Pat. No. 6,298,842 Sims (2001) discloses a damper for archery bow limbs known as the “LimbSaver”. This device is mushroom shaped, with a head and integral stem fabricated from a elastomeric polymer known in the archery industry as “NAVCOM”. The stem is capable of oscillating over a 360 degree span in directions generally normal to the longitudinal axis of the device. The peripheral part of the head can oscillate around its circumference in directions generally paralleling that axis. U.S. Design Pat. No. D445,161 also depicts this mushroom shaped head and stem arrangement mounted to an archery bow limb. 
         [0010]    Other manufactures have also patented archery bow limb dampers, including U.S. Pat. No. 6,684,874 Mizek (2004), U.S. Pat. No. 6,910,472 Mizek (2005) this design is marketed under the name of “ThunderBlox”, by NAP. This product is an integral base and body, wherein the body is shaped like an inverted pyramid as it extends away from the base. It is hollow on top with four very small tabs placed inside. These tabs are free to vibrate inside the open hollow space when an arrow is released from an archery bow. The drawback with this design is that the mass of the tabs are negligible. 
         [0011]    U.S. Pat. No. 6,712,059 Donovan (2004) describes a device with a base that mounts flat to the bow limb and has a plurality of fins extending up from the base and perpendicular to the surface of the bow limb. The forces placed on a damper of this arrangement act normal to the longitudinal axis of the fins when mounted on a parallel limb bow limiting its effectiveness. 
         [0012]    Others also marketed limb damper devices from the following: 
         [0000]    Alpine Archery limb dampers, 
       Diamond Hush Kit, 
     CSS/Richwood Archery Tuners, 
       [0013]    Barrie Archery Hemi limb dampers,
 
and Hoyt Archery Alpha Shox limb dampers.
 
         [0014]    While some of these devices will work to a certain degree, other devices did little more than add weight to the bow limb and could not do a very good job of vibration dampening due to the stiffness of the materials used. Which leads to another important consideration to take into account, the choice of materials. As now there are elastomeric polymer compounds that are considered gels by their hardness scale that can be injection molded. For a thermoplastic elastomer to be classified as a gel the hardness must be 10 Shore A or less, and into the Shore OO scale. Older gel formulations required long cure times in the mold, and some required a protective coating to prevent deformation and drying out. These types of gel devices were often used for arm rests and shoe insoles, and would normally never be used as a vibration damper device unless sealed in a container as they were too fragile and susceptible to damage. The recent developments of these newer materials will prove to be far more effective for vibration dampening devices then have ever been realized before. 
         [0015]    One prior art of the inventor that seems to work well with parallel mounted limbs is the BowJax LimbJax, it uses four flexible members or arms that have integral balls at the distal end of arms. When an arrow is released from the bow, the four balls rebound against the surface of the bow limb canceling out vibrations. While this arrangement seems to work very effectively on solid limb bows with parallel mounted limbs, it still could use some improvement for use on a split limb bow. Most split limb bows have the limbs spaced too far apart for the balls to make contact with the limbs, plus the height of the disc shaped mount used to fasten the damper to the limbs limit the effectiveness of the device. 
       SUMMARY OF THE INVENTION 
       [0016]    The object of the invention is to provide a vibration dampening device that can be deployed on both split limb bows as well as solid limb bows. One preferred embodiment that seems to work well needs only to have damper device rotated 90 degrees when attaching to the bow limb. It will be apparent to the reader skilled in the art that when mounting on a solid limb, the hemispherical contacts will be placed for maximum coverage on limb. Likewise, when mounting damper device on split limb, it will need to be rotated to achieve this maximum coverage on each side of limb. Through experiments with high speed photography it has been observed that the movable members of the Limbjax move very close to the same frequency. It was further observed that balls at end of arms could not reach the surface of the split limb because of the interference with the split limb mount. One preferred embodiment would incorporate four outboard movable members of the same length and longer than inventors prior art, with two shorter members, each placed 35 degrees between the longer members. This would allow the members to oscillate at different frequencies to further enhance the vibration dampening characteristics of the device. This new invention has been observed to be superior to inventors prior art, especially for split limb bows as the problems of a large gap between limbs and the interference of the split limb mount is now negated. The invention discloses a vibration damper which is molded as a single piece of a soft, flexible elastomeric polymer with a central hub and through hole to accept a mount for placing said damper on either solid limb or split limb bows. The invention further discloses a vibration damper that when mounted to either solid limb or split limb bows by means of a mechanism described herein would greatly reduce sound, vibration, and perceived hand shock when an arrow is released from an archery bow. The device is also constructed from a thermoplastic elastomer compound with a hardness range between 30 Shore OO to 13 Shore A. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0017]      FIG. 1  is a perspective view of device for dampening limb vibrations from one preferred embodiment of the invention for mounting on a solid limb bow. 
           [0018]      FIG. 2  is a top view of a device from  FIG. 1 . 
           [0019]      FIG. 3  is a sectional view of device from  FIG. 1 . 
           [0020]      FIG. 4  is a top view of a device for dampening limb vibrations from one preferred embodiment of the invention with mounting for a split limb bow. 
           [0021]      FIG. 5  is a sectional view of device shown in  FIG. 4 . 
           [0022]      FIG. 6  is a perspective view of device shown in  FIG. 4 . 
           [0023]      FIG. 7  is a sectional view of integral base and stem to receive device from one of the preferred embodiments disclosed. 
           [0024]      FIG. 8  is an perspective view of  FIG. 7 . 
           [0025]      FIG. 9  is an exploded sectional view of split limb mount. 
           [0026]      FIG. 10  is a side view of assembled device shown in  FIG. 9 . 
           [0027]      FIG. 11  is a top view of a device for dampening limb vibrations from one preferred embodiment of the invention for mounting on a solid limb. 
           [0028]      FIG. 12  is a sectional view of device from  FIG. 11 . 
           [0029]      FIG. 13  is a perspective view of device as seen from the bottom from  FIG. 11 . 
           [0030]      FIG. 14  is a top view of a device for dampening limb vibrations from one preferred embodiment of the invention with mounting for a split limb bow. 
           [0031]      FIG. 15  is a sectional view of device from  FIG. 14 . 
           [0032]      FIG. 16  is a perspective view of device as seen from the bottom from  FIG. 14 . 
           [0033]      FIG. 17  is a top view of a device for dampening limb vibrations from one preferred embodiment of the invention for mounting on a solid limb bow. 
           [0034]      FIG. 18  is a sectional view of device from  FIG. 17 . 
           [0035]      FIG. 19  is a perspective view of device from  FIG. 17 . 
           [0036]      FIG. 20  is a top view of device for dampening limb vibrations from one preferred embodiment of the invention with mounting for a split limb bow. 
           [0037]      FIG. 21  is a sectional view of device from  FIG. 20 . 
           [0038]      FIG. 22  is a perspective view of device from  FIG. 20 . 
           [0039]      FIG. 23  is a top view of one preferred embodiment from  FIGS. 11  thru  13  mounted to the surface of a section of a solid limb for demonstration. 
           [0040]      FIG. 24  is a sectional view from  FIG. 23  of the device on a solid limb. 
           [0041]      FIG. 25  is a top view of one preferred embodiment from  FIG. 14  thru  16  mounted to the surface of a section of a split limb for demonstration. 
           [0042]      FIG. 26  is a sectional view of device from  FIG. 25  showing how device is attached across the split limbs. 
           [0043]      FIG. 27  is a perspective view of one of the preferred embodiments mounted on both top and bottom limbs of a solid limb bow. Bowstrings and cables as well as other accessories are left out of view as they are not relevant to the invention. 
           [0044]      FIG. 28  is a perspective view of one of the preferred embodiments mounted on both top and bottom limbs of a split limb bow. 
           [0045]      FIG. 29  is a side view of an archery bow with a more conventional limb arrangement with one of the preferred embodiments attached to each limb. 
           [0046]      FIG. 30  is a side view of a more modern archery bow with a parallel limb arrangement with one of the preferred embodiments attached to each limb. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0047]      FIGS. 1-3  show a device  10  for reducing vibration and shock in a solid limb archery bow according to one preferred embodiments of this invention. This embodiment show device with twelve arms  20  with hemispherical contacts  30  top and bottom of arms  20 . The bottom contact  30  is the one that makes contact with the limb when an arrow is released from an archery bow, the top is for cosmetic purposes as well as adding mass to the end of the arms  20 .  FIG. 3  shows the cross sectional view of the invention. Integrated base and stem  40  is inserted through the passage  11  of the body  10  and held in place by the retaining cap  50 . The integral base and stem  40  are of a rigid plastic allowing only the arms  20  with hemispherical contacts  30  from device  10  to move. This version of the preferred embodiment uses an adhesive or double stick tape to mount to a solid limb bow, the adhesive or tape is placed on the flat bottom of base  40  at  41 . 
         [0048]      FIGS. 4-6  show a device  10  for reducing vibration and shock in a split limb archery bow according to one preferred embodiments of this invention. The previous device  10  described in  FIGS. 1-3  is further mounted to an assembly for installing device  10  on a split limb. This assembly uses one disc  60  which is attached to integral base and stem  40  by adhesive, double stick tape or ultrasonic welding. Disc  60  contains a threaded female insert  65  and is covered with a soft polymer disc cover  61  to place between  60  and the limb to prevent wear on the bow limb finish. The bottom disc cover  71  is placed against other side of limb to protect finish and contains disc  70 . Disc  70  has an included eighty-two degree counter sink for the flat head screw  75 . When the two discs  60  and  70  are aligned the flat head screw  75  is threaded into insert  65  and when tightened, clamps discs to split limb. The soft polymer disc covers  61  and  71  help to keep device from moving on the limb when in use without having to over tighten flat head screw  75 . 
         [0049]      FIGS. 7-8  show the integral base and stem  40  used to attach device  10  to a solid limb bow or the split limb assembly. The integral base and stem  40  and retaining cap  50  are injection molded out of a rigid plastic known as ABS. The stem  45  is inserted through the passage  11  of the device  10 , then held in place by the retaining cap  50 . The retaining cap  50  has a large enough diameter flange  51  to prevent device  10  from slipping off base and stem  40 . The protruding portion  55  of the retaining cap  50  is glued into hollow end  49  of base and stem  40 . The bottom surface of base  40  at  41  uses adhesive methods described to attach directly to the solid limb of a bow, or attach to top side of disc  60  to install on a split limb bow. Since the base and stem  40  are of a hard plastic, only the arms  20  from device  10  are allowed to move when an arrow is released from an archery bow. 
         [0050]      FIG. 9  is an exploded sectional view showing how all of the components are placed together for mounting device  10  onto a split limb bow. From the top down, retaining cap  50  securely holds device  10  onto integral base and stem  40 . Threaded female insert  65  is first pressed into hole  66  of disc  60 , then bottom of base  40  at  41  is fastened into the counter bore  69  on the top side of disc  60  using one of the adhesive methods described. Disc covers  61  and  71  go between the top and bottom surfaces of the limbs and the discs  60  and  70  to prevent wear on the finish of the bow limbs. This also prevents the discs from sliding on the limbs without over tightening flat head screw  75 . The discs  60  and  70  are injection molded out of glass filled ABS and are very rigid to span across the gaps encountered in most split limb bows. 
         [0051]      FIG. 10  is an assembled side view of the mount from  FIG. 9  for attaching one of the preferred embodiments of device  10  onto a split limb bow. 
         [0052]      FIGS. 11-16  show a device  10  of one preferred embodiment for reducing vibration and shock in an archery bow limb, solid or split. This embodiment shown has four arms  20  that are of equal length, with two shorter arms  20  so that the arms  20  vibrate of phase when an arrow is released from an archery bow. As can be seen from the views, the integral mass  31  at the end of arms  20  adds more weight to the end of the arms  20 . This feature puts more mass in contact with the limbs at contact points  30 . The configuration of device  10  allows it to work well on solid limb bows and split limbs bows by simply rotating device  10  ninety degrees. The long arms  20  can reach out to the split limbs on either side of device  10 , likewise the arms  20  would be two long to be placed the same way on a solid limb bow as the hemispherical contacts  30  would miss the limb. When rotated ninety degrees then the contacts  30  make full contact to the limb surface. This preferred embodiment lends itself to more versatility as one size fits both solid and split limb bows. 
         [0053]      FIGS. 17-22  show a device  10  of one preferred embodiment for reducing vibration and shock in an archery bow limb, solid or split. The embodiment presented in these views has much larger spherical masses  30  attached to arms  20 . The device  10  shown also has round arms  20 , but arms  20  can be any cross-sectional shape. The much larger mass of this preferred embodiment puts more elastomeric material in contact with the excited surface of the bow limbs. The integral base and stem  40  with retainer cap  50  holds device  10  securely. Since the base and stem  40  are rigid plastic only the flexible elastomeric polymer arms  20  allow the spherical masses  30  to bounce against and away from the bow limbs when an arrow is released from an archery bow. 
         [0054]      FIGS. 23-24  shows the device  10  from one preferred embodiment for reducing vibration and shock mounted on a section of a solid limb  1  as seen from the top and sectional views. The limb  1  is sectioned along the longitudinal axis of the limb  1 . As can be seen in  FIG. 24  the arms  20  and mass  31  and contact  30  are free from limb running parallel to the surface of the limb  1 . The central hub of device  10  is held on the rigid base and stem  40  through the passage  11  so that this portion of the device  10  cannot flex. The arms  20  are free to move when an arrow is released from an archery bow, allowing the mass  31  with the hemispherical contacts  30  to rebound against the surface of the excited surface of the bow limb  1 .  FIG. 23  illustrates how the device needs to be placed to allow the best coverage on a solid limb bow. 
         [0055]      FIGS. 25-26  show the device  10  from one preferred embodiment for reducing vibration and shock mounted on a section of a split limb  2  as seen from the top and sectional views. The sectional view illustrates how the rigid discs  60  and  70  span the gap between the split limbs  2 . The device  10  is centered between the split limb  2  and the flat head screw  75  is tightened to securely hold device  10  to the split limbs  2 . Notice that the device  10  of this preferred embodiment is attached with the shorter arms  20  perpendicular to the longitudinal axis of the split limbs  2 . As in  FIGS. 23-24  the arms  20  and masses  31  and contacts  30  are parallel to the surface of limb  2  and do not touch the limb  2  until an arrow is released from an archery bow, at which time the contacts  30  rebound against the bow limb  2 . 
         [0056]      FIGS. 27-28  show two devices  10  from one preferred embodiment for reducing vibration and shock mounted on both a solid limb  1  bow from  FIG. 27  and a split limb  2  bow from  FIG. 28 . The limbs  1  and  2  are fastened to the bow riser  3  using bolts. As can be seen from these views the device  10  is mounted on the inner side of limbs  1  and  2  in the same general location top and bottom. Although the devices could be mounted to the other sides of the limbs  1  and  2 , they are most effective when mounted as shown due to the forces acting on the limbs  1  and  2  when an arrow is released from an archery bow. In  FIGS. 27-28  the bow riser  3  is held by the handle  4 , as the bow is drawn back the cams  5  roll over and the limbs  1  and  2  flex toward each other. When the arrow is released the device  10  rebounds its members against the bow limbs  1  and  2  when the limbs come to an abrupt stop at their undrawn state. The string and cables as well as accessories are left out of the views as they are not relevant to the invention. 
         [0057]      FIGS. 29-30  show the difference between a conventional bow limb arrangement and a more modern parallel limb arrangement. From  FIG. 30  although exaggerated, more bows these days are going toward a perfect parallel limb arrangement. When these modern bows are drawn back to full draw the limbs actually go beyond parallel. This arrangement was originally conceived as a way for the forces in the limbs to cancel each other out thus reducing vibration, hand shock and noise. There still exists a need for a device  10  like one of the preferred embodiments described be mounted on the limbs  1 . 
         [0058]    The drawings and descriptions represent only some of the embodiments of the invention. It is realized that skilled persons will understand that there are many ways to make a vibration damper according to the principles disclosed with additional embodiments without departing from spirit and scope of the claims. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                   
               
               
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       OTHER REFERENCES CITED 
       [0000]    
       
         Alpine Archery limb dampers—www.alpinearchery.com 
         Diamond Hush Kit, from Ad on page 43 Inside Archery December 2005 
         CSS/Richwood Archery Tuners, from Ad on page 51 of Arrow Trade November 2005 
         Barrie Archery Hemi limb damper, from Ad on page 99 Bowhunt America October/November 2005 
         Hoyt Archery Alpha Shox limb dampers, page 5 of Peterson&#39;s Bowhunting January/February 2006