Patent Publication Number: US-2006011181-A1

Title: Limb suspension system

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims priority to and all the benefits of U.S. Provisional Application Ser. No. 60/578,346, filed on Jun. 9, 2004 and entitled “Limb Suspension System.” 
    
    
     FIELD OF THE INVENTION  
      The invention relates to an archery bow. More particularly, this invention relates to an actuator that absorbs shock after each shot of an archery bow to reduce vibration of the archery bow.  
     DESCRIPTION OF RELATED ART  
      Archery bows typically include a pair of limbs each rigidly connected to a limb pocket or a riser. A wheel or cam is commonly rotatably attached to a distal end of the limbs and a bowstring and harness system is wound around the wheels or cams of the limbs. The limbs are typically flexible such that as the archery bow is drawn, potential energy is typically stored within the limbs themselves. When the bowstring is released, the potential energy is converted to kinetic energy for propelling an arrow as the limbs return to a rest position.  
      The accuracy of the archery bow largely depends on the elimination of extraneous motions of the archery bow. As the bowstring is released, the limbs vibrate causing the bowstring to oscillate as the arrow leaves the archery bow. The oscillation affects the trajectory of the arrow, greatly impacting accuracy while also causing unwanted noise and hand shock. Therefore, it is also desirable to provide an archery bow that absorbs shock after each shot for reducing vibration of the archery bow.  
     SUMMARY OF THE INVENTION  
      According to one aspect of the invention, an archery bow includes a limb extending between opposing first and second ends. A limb pocket receives the first end of the limb. A limb bolt actuator is positioned to retain the limb within the limb pocket for decoupling the limb from the limb pocket and dampening vibration exerted through the limb as the limb flexes and releases during each shot of the archery bow.  
      According to another aspect of the invention, an archery bow includes a riser extending between opposing ends. A limb is operably coupled to each of the opposing ends of the riser. A limb bolt actuator is positioned to retain each of the limbs against one of the opposing ends of the riser for decoupling the limbs from the riser and dampening vibration exerted through the limbs as the limbs flex and release during each shot of the archery bow.  
      According to yet another aspect of the invention, an archery bow includes a riser extending between opposing ends. First and second limbs each extend between opposing first and second ends. The first end of each of the first and second limbs is operably coupled to the riser. A limb pocket is operably coupled to each of the first and second limbs at the first end therof. A limb pocket actuator is positioned between the riser and the first end of each of the first and second limbs for decoupling the first and second limbs from the limb pocket and dampening vibration exerted through the first and second limbs as the first and second limbs flex and release during each archery bow shot. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:  
       FIG. 1  is a side view of an archery bow including a riser and first and second limbs extending out from the riser;  
       FIG. 2  is a fragmentary, perspective view of the archery bow including a limb bolt actuator disposed adjacent the first limb;  
       FIG. 3  is a side view of a portion of the archery bow including the limb bolt actuator;  
       FIG. 4  is a cross-sectional view of a portion of the archery bow including the limb bolt actuator fixedly secured to a limb pocket;  
       FIG. 5  is an exploded, perspective view of the limb bolt actuator;  
       FIG. 6  is a fragmentary, perspective view of an archery bow including the limb bolt actuator and a limb pocket actuator fixedly secured to the riser;  
       FIG. 7  is a fragmentary, rear perspective view of the archery bow showing the limb bolt and limb pocket actuators; and  
       FIG. 8  is a cross-sectional view depicting a housing and actuating member of the limb pocket actuator. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to  FIG. 1 , an archery bow, generally shown at  10 , includes a riser  12  extending between opposing ends  14 ,  16 . Although a compound bow is shown in  FIG. 1 , it is contemplated that the following description is equally applicable to other bows including, but not limited to, mechanical bows and cross bows. The archery bow  10  includes first  18  and second  20  limbs extending out from the respective ends  14 ,  16  of the riser  12 . Each of the first  18  and second  20  limbs includes a first end  22  proximate to one end  14 ,  16  of the riser  12 . A wheel or cam  24 ,  26  is rotatably coupled to an opposing second end  28  of each of the first  18  and second  20  limbs. A harness or cable system  30  and a bowstring  32  are wound around and between each wheel or cam  24 ,  26  and pulled in tension by the first  18  and second  20  limbs.  
      The archery bow  10  further includes a pair of limb pockets  34 ,  36  for pivotally attaching the respective first  18  and second  20  limbs to the opposing ends  14 ,  16  of the riser  12 . A pocket axle  38  pivotally couples each of the respective limb pockets  34 ,  36  to the opposing ends  14 ,  16  of the riser  12 . Specifically, each end  14 ,  16  of the riser  12  includes a pair of spaced apart fingers  40 ,  42 , shown in  FIG. 2 , for receiving the pocket axle  38  therethrough.  
      A limb bolt actuator, generally indicated at  44 , is positioned to retain the first end  22  of each of the first  18  and second  20  limbs within the respective limb pockets  34 ,  36  for decoupling the first  18  and second  20  limbs from the respective limb pockets  34 ,  36 . Only the limb bolt actuator  44  associated with the first limb  18  and one of the limb pockets  34  will be shown and described from this point forward with the understanding that the same applies equally to the limb bolt actuator  44  associated with the second limb  20  and other limb pocket  36 .  
      Referring to  FIGS. 2 through 5 , the limb bolt actuator  44  includes a limb bolt  46  having a cap  48  and a threaded shaft  50  extending out therefrom. The cap  48  includes a screw head  52 . The threaded shaft  50  is received within a cylindrical bore  54  formed in the limb pocket  34 . Preferably, the cylindrical bore  54  is formed within a protrusion  55  of the limb pocket  34 , which extends upwards through the first limb  18 . The cylindrical bore  54  includes a screw thread  56  that rotatably engages the threaded shaft  50  of the limb bolt  46  for tightening and loosening the limb bolt  46  into and out of the cylindrical bore  54 , respectively. It should, however, be appreciated that the attachment between the limb bolt  46  and the limb pocket  34  may be achieved in any of numerous ways.  
      The limb bolt actuator  44  also includes an actuating member  58  held between first  60  and second  62  interlocking devices or retainers. The actuating member  58  includes an aperture  64  for receiving the limb bolt  46  therethrough. It is, however, contemplated that the actuating member  58  may have any of various shapes and sizes. Preferably, the actuating member  58  is formed from an elastomeric material such as urethane or polyurethane in any durometer. Preferably, the durometer range for the elastomeric material is from 0 to 98 on the Shore 00 scale, 0 to 100 on the Shore A scale, and 0 to 75 on the Shore D scale.  
      It is also appreciated that the actuating member  58  may be a mechanical suspension system such as a coil spring, linear actuator, rotary actuator, and/or air bladder. If such a mechanical suspension system is utilized, the first  60  and second  62  interlocking devices may not be needed.  
      The first  60  and second  62  interlocking devices each includes an aperture  66  for receiving the limb bolt  46  therethrough. In addition, the first  60  and second  62  interlocking devices, which may be formed from a metal or plastic material, are shaped to complementarily and lockingly engage one another. Thus, the first  60  and second  62  interlocking devices are suited to retain and support the actuating member  58  therebetween. Depending on the elastomeric material chosen for the actuating member  58 , the limb bolt actuator  44  may be a static or dynamic system such that the actuating member  58  in the limb bolt actuators  44  supports the entire load or a portion of the load of the first  18  and second  20  limbs.  
      A generally rigid limb bezel  68  receives the limb bolt  46  therethrough and is disposed between the cap  48  and the first interlocking device  60 . The limb bezel  68  is formed from a metal material, preferably aluminum. The limb bezel  68  supports the limb bolt actuator  44  and retains the first limb  18  within the limb pocket  34 . Further, the limb bezel  68  maintains the loading perpendicular to the limb bolt actuator  44 .  
      The system lets the natural loading of the of archery bow  10  naturally compress the actuating member  58 . In other words, although the limb bolt actuator  44  is rigidly connected to the limb pocket  34 , the actuating member  58  is floatable even as it is retained between the first  60  and second  62  interlocking devices.  
      At rest, the archery bow  10  is statically supported while during the draw or at full draw, the first  18  and second  20  limbs pivot due to the increasing forces within the cable system  30 . At the same time, the actuating members  58  compresses to store energy for dissipating shock after the shot of the archery bow  10 . Thus, each limb bow actuator  44  acts as a shock absorber and isolator for dampening vibration exerted through the first  18  and second  20  limbs.  
      Referring back to  FIG. 1 , an actuating device, generally shown at  70 , extends between each end  14 ,  16  of the riser  12  and the respective limb pockets  34 ,  36 . The actuating device  70  includes a resilient material  72  and first  74  and second  76  connectors, as shown in  FIGS. 2 and 3 . The resilient material  72  is preferably an elastomeric material such as urethane or polyurethane in any durometer.  
      A limb axle  78  extends through both the first connector  74  and a portion of one of the limb pockets  34 . The first connector  74  thus rotates about the limb axle  78  to pivotally secure the limb support actuator  70  to the limb pocket  34 . A riser axle  80  extends through both the second connector  76  and a portion of the riser  12 . The second connector  76  thus rotates about the riser axle  80  to pivotally secure the limb support actuator  70  to the riser  12 .  
      Referring to  FIGS. 6 through 8 , an alternate embodiment of the archery bow  10  includes the limb bolt actuator  44  positioned to retain the first end  22  of the first limb  18  against one end  14  of the riser  12  for decoupling the first limb  18  from the riser  12 . The bolt  46  is screwed into a swivel member  81  within an interior of the riser  12  to fixedly secure the limb bolt actuator  44  thereto. It is, however, contemplated that the attachment of the limb bolt actuator  44  to the riser  12  may be achieved in any of numerous ways. Apart from the site of attachment, the limb bolt actuator  44  that is secured to the riser  12  is identical to the limb bolt actuator  44  secured to the limb pocket  34  described above.  
      Although the limb bolt actuator  44  is shown coupling the first limb  18  to one end  14  of the riser  12 , another limb bolt actuator  44  is provided to couple the second limb  20  to the other end  16  of the riser  12 .  
      Once again, the system lets the natural loading of the of archery bow  10  naturally compress the actuating member  58 . In other words, although the limb bolt actuator  44  is rigidly connected to the riser  12 , the actuating member  58  is floatable even as it is retained between the first  60  and second  62  interlocking devices.  
      Still referring to  FIGS. 6 through 8 , a limb pocket actuator, generally shown at  82 , is fixedly secured to one end  14  of the riser  12 . The limb pocket actuator  82  is positioned between the end  14  of the riser  12  and the first limb  18  for decoupling the first limb  12  from the limb pocket  34 . The limb pocket actuator  82  includes a housing  84  fixedly secured to the end  14  of the riser  12 . The housing  84  is formed from a metal material, preferably aluminum.  
      A portion of an actuating member  86  is received within the housing  84 , and a remaining portion of the actuating member  86  abuts an inboard surface  88  of the first limb  18 . More specifically, the actuating member  86  is molded or bonded to the housing  84 . Both the housing  84  and the actuating member  86  may have any of varying shapes or sizes. The actuating member  86  is preferably an elastomeric material such as urethane or polyurethane in any durometer. Preferably, the durometer range for the elastomeric material is from 0 to 98 on the Shore 00 scale, 0 to 100 on the Shore A scale, and 0 to 75 on the Shore D scale. Depending on the elastomeric material chosen for the actuating member  58 , the limb pocket actuator  82  may be a static or dynamic system such that the actuating member  58  in the limb pocket actuators  82  supports the entire load or a portion of the load of the first  18  and second  20  limbs. Further, the actuating member  86  is floatable relative to the rigid and stationary housing  84 .  
      It is appreciated that although the limb pocket actuator  82  is shown only with regard to the first limb  18  and one end  14  of the riser  12 , the limb pocket actuator  82  is also secured to the other end  16  of the riser  12  adjacent the first end  22  of the second limb  20 .  
      Finally, it is contemplated that although the limb bolt actuator  44  and the limb pocket actuator  82  are shown either with one another or with another actuator, such as the actuating device  70 , in  FIGS. 1 through 8 , the archery bow  10  may be configured to include only one type of actuator, i.e., the limb bolt actuator  44  mounted in the limb pockets  34 ,  36 , the limb bolt actuator mounted in the riser  12 , or the limb pocket actuator  82 .  
      The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.