Eccentric pulley mechanism for compound archery bow

In a compound archery bow including a pair of resilient bow limbs which are deflected from a braced position to a drawn position by the operation of a bowstring interconnected to said bow limbs through at least one tension cable, an eccentric pulley mechanism comprising:

• an inner eccentric wheel pivotally mounted about a fixed axis at an end portion of one of said bow limbs;
• an outer pulley wheel including a bowstring track means and a tension cable track means, said outer pulley wheel being rotatable relative to and about said eccentric wheel;
• and
• interengaging means for interengaging said eccentric wheel and said pulley wheel such that said eccentric wheel and said pulley wheel become operative for eccentric rotation about said fixed axis, said mechanism being operable for providing a first mechanical advantage when drawing said bowstring such that said pulley wheel rotates relative to said eccentric wheel and pays out a predetermined stretch of said bowstring while taking up a shorter stretch of said cable, said interengaging means interengaging said pulley wheel and said eccentric wheel in said drawn position,
• said mechanism further being operable for providing a second mechanical advantage when propelling an arrow such that when said bowstring is released said interengaged pulley wheel and eccentric wheel eccentrically rotate back about said axis and rapidly pay out said stretch of cable while taking up said stretch of bowstring thus transferring an increased velocity to said propelled arrow, said interengaging means automatically disengaging after said bow limbs return to said braced position.