Patent attributes
A pulley arrangement for a compound archery bow (100) that combines the forgiveness and symmetry of a “dual cam” system with the positive draw stop (hard wall), enforced synchronization (or built-in timing) between opposite pulley assemblies, and high let-off associated with “single cam” systems. The pulley rigging (112) includes only a single cable reference anchor to a limb (104, 106). Certain pulleys (108, 110) include rotating module portions (183, 214) effective to change the wrapped lengths of power and control cables (270, 272) to change draw length (LD) while the bow (100) is strung, and at a brace condition with the drawstring (116) under full tension, and without changing the timing of the pulley members (108, 110), or changing the lengths of rigging members (112). Certain embodiments include a resilient element (196) in a positive draw stop (194) to reduce noise as the draw stop (194) engages a rigging element (270). A resilient element (206) adapted to reduce drawstring vibration may further be included, in one or more pulleys, and arranged to contact the drawstring (116) as the pulleys (108, 100) over-rotate. A preferred mounting arrangement employs a flanged bearing assembly (200) to resist bearing walk relative to the pulley on which the bearing assembly (200) is installed. Certain preferred embodiments of pulleys (108, 110) include a spiral cam shape at a let-off portion of the string cams (150, 210).
