US Patent 7143757 Compound bow with cam arrangement

An archery bow (B) having at least one draw force module (1a or 1b). The module includes a concentric bowstring (3) pathway (12a) and at least one eccentric cable (6a) pathway (7a) with a decreasing radius proportional to the increasing spring rate of the flexing limb so the peak weight remains the same through a portion of the draw force curve and decreases at the end.