摘要 |
A base cam/power cam assembly for a compound bow is disclosed, the base cam/power cam assembly comprising: a) a base cam for letting out a draw cable when the assembly rotates as the bow is drawn, the base cam having an oblong shape with a major axis and a minor axis and an eccentric rotation axis substantially perpendicular to the plane of the base cam; b) a power cam for taking up a power cable when the assembly rotates as the bow is drawn, the power cam being secured to the base cam and having an oblong shape with a major axis and a minor axis and an eccentric rotation axis substantially perpendicular to the plane of the base cam and coinciding with the rotation axis of the base cam; and c) an eccentric attachment for securing the end of a let-out/take-up cable to the assembly and for letting out the let-out/take-up cable when the assembly rotates as the bow is drawn. The major axes of the base cam and power cam are angularly displaced from one another, and are arranged so that a draw cable lever arm increases and a power cable lever arm decreases when the assembly rotates as the bow is drawn. Efficiencies of at least 82% and as large as 94% are achieved.
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