Bowstring Cam for Compound Bow

Abstract

A bowstring cam assembly for compound archery bow has a bowstring cam member that is journaled at an end of the bow power limb. First and second power cams are affixed onto the bowstring cam member to rotate with it, and first and second flexible inextensible cam cables extend over the periphery of the associated power cams. The cam cables and the power cams cooperate to determine draw characteristics for the bow. The bowstring cam member is provided with an acircular cam profile. The second power cam is situated to one side of the axis of the bowstring cam, such that at an end of travel, i.e., at full release, both the first and second power cables are pulling in a common direction.

1 . An upper and/or lower bowstring cam assembly adapted to be rotatably held at an axis thereof onto a power limb of a compound archery bow, the bowstring cam assembly comprising:
 a bowstring cam member provided with an acircular profile and having a peripheral groove thereon adapted to receive a bow string;   first and second power cams affixed onto the bowstring cam member to rotate therewith, each of said first and second power cams each having a peripheral groove respectively adapted to receive first and second flexible inextensible power cables, such that the cam cables and the power cams cooperate to determine draw characteristics for said bow; and wherein   said second power cam is situated entirely to one side of the axis of the bowstring cam assembly, such that at one end of rotational travel of the bowstring cam assembly both said first and second power cables are situated on the same side of said axis, and are pulling in a common direction to rotate the bowstring cam assembly.   
   
   
       2 . The bowstring cam assembly of  claim 1  comprising a pivot pin disposed on said axis and extending outward beyond said second power cam. 
   
   
       3 . The bowstring cam assembly of  claim 1  comprising a crank member affixed onto said second power cam, and defining an offset, and a pivot pin extending out from said crank member at said axis. 
   
   
       4 . The bowstring cam assembly of  claim 1  wherein said first power cam is affixed adjacent said bowstring cam member, and said second power cam is affixed to said first power cam on a side thereof remote from the bowstring cam member. 
   
   
       5 . The bowstring cam assembly of  claim 4  comprising a crank member affixed onto said second power cam, and defining an offset, and a pivot pin extending out from said crank member at said axis. 
   
   
       6 . An upper and/or lower bowstring cam assembly adapted to be rotatably held at an axis thereof onto a power limb of a compound archery bow, the bowstring cam assembly comprising:
 a bowstring cam member provided with an acircular profile and having a peripheral groove thereon adapted to receive a bow string;   a pair of first power cams affixed onto opposite sides of the bowstring cam member to rotate therewith;   a pair of second power cams affixed onto opposite sides of the bowstring cam member to rotate therewith;   each of said first and second power cams having a peripheral groove respectively adapted to receive first and second flexible inextensible power cables, such that the cam cables and the power cams cooperate to determine draw characteristics for said bow; and wherein   said second power cams each are situated entirely to one side of the axis of the bowstring cam assembly, such that at one end of rotational travel of the bowstring cam assembly both said first and second power cables are situated on the same side of said axis, and are pulling in a common direction to rotate the bowstring cam assembly.   
   
   
       7 . The bowstring cam assembly of  claim 6  comprising pivot pins disposed on said axis and extending outward beyond said second power cams. 
   
   
       8 . The bowstring cam assembly of  claim 6  comprising a pair of crank members affixed onto said second power cams, and defining an offset, and a pair of pivot pins extending out from said crank members at said axis. 
   
   
       9 . The bowstring cam assembly of  claim 1  wherein said first power cams are affixed adjacent said bowstring cam member, and said second power cams are affixed to said first power cams on sides thereof remote from the bowstring cam member. 
   
   
       10 . The bowstring cam assembly of  claim 4  comprising a pair of crank members affixed respectively onto said second power cams, and defining offsets, and a pair of pivot pins extending out from said crank member at said axis.