Dual-feed single-cam compound bow

Abstract

A cam is eccentrically journaled at one end of a compound archery bow and a pulley is journaled at the other end of the bow. A cable passes around the pulley to form a bowstring section and a second cable section, both sections forming a dual feed single cam compound bow. The amount of feed out to both ends of the bowstring is approximately the same. One embodiment of the cam provides a large radius cam groove and a smaller radius cam groove which are designed to synchronize the rate of cable feed out at both ends of the bowstring section during the drawing operation. An anchor cable is provided to tie the two limbs of the bow together during the flexing of the bow.

1. A compound archery bow comprising first and second bow limbs attached to a handle, said bow limbs having axle pins therein and wherein an eccentrically rotatably mounted cam defining a bowstring section cam and a return section cam is mounted on one of said axle pins with said axle pin passing through at least said return section cam, a cable having a bowstring section attached to said bowstring section cam and a return section attached to said return section cam, a bowstring cable and a return cable attached to said eccentrically mounted cam,  whereby rotation of the eccentrically rotatably mounted cam by the bowstring cable  section causes the bowstring cable  section to be let off and whereby during at least a portion of said cam rotation the return cable  section is also  let off. 
     
     
       2. A compound archery bow asset forth in  claim 1  and further including an anchor cable attached to the cam and whereby the rotation of the eccentrically rotatably mounted cam by the bowstring cable  section causes the anchor cable to be taken up. 
     
     
       3. An  A compound archery bow comprising an eccentrically rotatably mounted cam defining a bowstring section cam and a return section cam, said eccentrically rotatable cam being mounted on a bow limb with an axle passing through said cam, a bowstring  cable attached to the cam, a return cable attached to the cam  said cable having a bowstring section attached to said bowstring section cam and a return section attached to said return section cam and means for rotating the cam to cause the bowstring cable  section to be let off and during at least a portion of said cam rotation to cause the return cable  section to be let off. 
     
     
       4. An eccentrically rotatably mounted cam, bowstring cable and return cable  A compound archery bow as set forth in  claim 3 , and further including an anchor cable attached to the cam and whereby the rotation of the cam causes the anchor cable to be taken up. 
     
     
       5. The compound archery bow of  claim 3 , wherein said bowstring section cam and said return section cam define a large periphery cam and a small periphery cam. 
     
     
       6. The compound bow of  claim 5 , wherein said small periphery cam has an eccentric periphery. 
     
     
       7. The compound bow of  claim 6 , wherein said large periphery cam has an eccentric periphery. 
     
     
       8. A compound archery bow comprising first and second bow limbs attached to a handle, an eccentrically rotatably mounted cam mounted on one of said bow limbs with an axle passing through said cam, an anchor cable attached to an axle mounted in the second of said first and second bow limbs, a bowstring cable and a return cable attached to said eccentrically mounted cam, whereby rotation of the eccentrically rotatably mounted cam by the bowstring cable causes the bowstring cable to be let off and the anchor cable to be taken up, and, whereby during at least a portion of said cam rotation the return cable is also let off. 
     
     
       9. A compound archery bow as set forth in  claim 8 , wherein the first and second bow limbs each have a mounting fork, wherein a single axle is attached to each of said bow limbs through the respective mounting fork, and wherein each said single axle spans the respective mounting fork. 
     
     
       10. A compound archery bow comprising first and second bow limbs attached to a handle, said bow limbs each having a single axle pin therein and wherein an eccentrically rotatably mounted cam is mounted on the single axle pin on said second bow limb, an anchor cable attached to an axle pin in said first bow limb, a bowstring cable section attached to the cam, a return cable section attached to the cam, means for rotating the cam to cause the bowstring cable section to be let off and during at least a portion of said cam rotation to cause the return cable section to be let off, and whereby the rotation of the cam causes the anchor cable to be taken up by said cam. 
     
     
       11. A compound archery bow as set forth in  claim 10 , wherein the first and second bow limbs each have a mounting fork, wherein each of the single axle pins is attached to said bow limbs through the respective mounting fork, and wherein said single axle pins each span the respective mounting fork. 
     
     
       12. A compound archery bow comprising first and second bow limbs attached to a handle, an eccentrically rotatably mounted cam mounted on one of said bow limbs with an axle pin extending through said cam, an anchor cable attached between an axle pin on the one of said bow limbs opposite said cam and said eccentrically mounted cam, a bowstring cable and a return cable attached to said eccentrically mounted cam, whereby rotation of the eccentrically rotatably mounted cam by the bowstring cable causes the bowstring cable to be let off along an outer periphery of the eccentrically rotatably mounted cam, whereby during at least a portion of said cam rotation the return cable is let off along a path along a different length outer periphery of the eccentrically rotatably mounted cam, and whereby the rotation of the eccentrically rotatably mounted cam by the bowstring cable causes the anchor cable to be taken up. 
     
     
       13. A compound archery bow comprising first and second bow limbs attached to a handle, an eccentrically rotatably mounted cam defining a bowstring cam and a return cable cam mounted on one of said bow limbs with an axle extending through said bowstring cam and said return cable cam, an anchor cable attached to an axle in the one of said first and second bow limbs opposite said cam, a bowstring cable attached to said bowstring cam, a return cable attached to said return cable cam, means for rotating the cam to cause the bowstring cable to be let off and during at least a portion of said cam rotation to cause the return cable to be let off, and whereby the rotation of the cam causes the anchor cable to be taken up by said cam. 
     
     
       14. A compound archery bow comprising first and second bow limbs attached to a handle, said bow limbs each having a single axle pin therein and wherein an eccentrically rotatably mounted cam is mounted on said second limb on one of said axle pins, an anchor cable attached between the axle pin on said first limb and said eccentrically mounted cam, a second cable having a bowstring section and a return section, whereby rotation of the eccentrically rotatably mounted cam by the bowstring section causes the bowstring section to be let off and whereby during at least a portion of said cam rotation the return section is also let off. 
     
     
       15. A compound archery bow as set forth in  claim 14 , whereby the rotation of the eccentrically rotatably mounted cam by the bowstring section causes the anchor cable to be taken up. 
     
     
       16. A compound archery bow as set forth in  claim 14 , wherein the first and second bow limbs each having a mounting fork, wherein a single axle pin is attached to each of said bow limbs through the respective mounting fork, and wherein each said single axle pin spans the respective mounting fork. 
     
     
       17. A compound archery bow comprising first and second bow limbs attached to a handle, said bow limbs each having a single axle pin therein and wherein an eccentrically rotatably mounted cam is mounted on said second limb on one of said single axle pins, an anchor cable attached between the axle pin on said first limb and the cam, a second cable having a bowstring section and a return section and means for rotating the cam to cause the bowstring section to be let off and during at least a portion of said cam rotation to cause the return section to be let off. 
     
     
       18. A compound archery bow as set forth in  claim 17 , whereby the rotation of the cam causes the anchor cable to be taken up. 
     
     
       19. A compound archery bow as set forth in  claim 17 , wherein the first and second bow limbs each have a mounting fork, wherein a single axle pin is attached to each of said bow limbs through the respective mounting fork, and wherein each said single axle pin spans the respective mounting fork. 
     
     
       20. A compound archery bow comprising
   first and second bow limbs attached to a handle, said bow limbs each having a mounting fork;        at least one of said bow limbs having an axle pin attached therein through the respective mounting fork, said axle pin spanning the mounting fork;        an eccentrically rotatable cam mounted on said at least one axle pin with said axle pin passing through said cam;        an anchor cable attached at one end to said eccentrically mounted cam and attached at an opposing end to an axle on the other of said bow limbs;        a bowstring cable section and a return cable section attached to said eccentrically mounted cam;        wherein said cam defines a bowstring cable path and a return cable path each path including at least a portion along an outer periphery of said cam, and each path defined outward of said axle pin;        whereby rotation of the eccentrically rotatably mounted cam by the bowstring cable causes the bowstring cable section and the return cable section to be let off along their respective bowstring cable path and return cable path at least during portions of said rotation, and whereby during at least a portion of said rotation the anchor cable is taken up by said cam.     
     
     
       21. A dual- feed single - cam compound bow comprising      a pair of flexible resilient bow limbs forming first and second outer bow limb ends with a handle connecting inner ends thereof,        a single drop - off cam journaled on an axle pin at the first outer bow limb end and having eccentric peripheral groove portions wherein each groove portion is journaled on said axle pin,        a pulley concentrically journaled at the second outer bow limb end and having peripheral concentric groove portions,        an elongated cable having an intermediate portion trained around the concentric pulley to form two cable sections extending between the pulley and the cam, one section forming a bowstring having feed - out end portions at both ends thereof and the other section forming a take - up portion at the pulley end thereof and a feed - out portion at the cam end thereof, both received in eccentric groove portions peripheral to the cam in a manner to provide a pair of feed - out sections extending from the cam toward the pulley,        the ends of the two cable sections being positively anchored to the cam to produce the desired drop - off rotation of the cam when the bowstring is drawn, and        an anchor cable extending between the two limbs with one end thereof fixed to the second bow limb end and the other anchor cable end fixed to the cam and trained in a take - up groove portion of the cam to produce controlled flexing of the bow limbs during the drawing of the bowstring.     
     
     
       22. A compound bow as set forth in  claim 21 , wherein said anchor cable has two sections at one end thereon, and wherein each such section is mounted to the second outer bow limb end on opposite sides of said pulley. 
     
     
       23. A dual- feed single - cam compound bow comprising      a pair of flexible resilient bow limbs forming first and second outer bow limb ends with a handle connection inner ends thereof,        a single drop - off cam journaled on an axle pin at the first outer bow limb end and having eccentric peripheral groove portions wherein each groove portion is journaled on said axle pin,        a pulley concentrically journaled at the second outer bow limb end and having peripheral concentric groove portions,        an elongated cable, having an intermediate portion trained around the concentric pulley to form two cable sections extending between the pulley and the cam, one section forming a bowstring having feed - out end portions at both ends thereof and the other section forming a take - up portion at the pulley end thereof and a feed - out portion at the cam end thereof, both received in eccentric peripheral groove portions of the cam in a manner to provide a pair of feed - out sections extending from the cam toward the pulley,        the ends of the two cable sections being positively anchored to the cam to produce the desired drop - off rotation of the cam when the bowstring is drawn, and        an anchor cable extending between the two limbs with one end thereof fixed to the second bow limb end and the other anchor cable end fixed to the cam and trained in a take - up groove portion of the cam to produce controlled flexing of the bow limbs during the drawing of the bowstring.     
     
     
       24. A compound bow as set forth in  claim 23  wherein said anchor cable has two sections at one end thereon, and wherein each such section is mounted to the second outer bow limb end on opposite sides of said pulley.