Synchronized segmentally interchanging pulley transmission system

Abstract

A segmented pulley transmission [] is provided. A pulley assembly [] is rotationally mounted on an axle []. The pulley assembly [] includes a core pulley [] having a first set of mating features on a peripheral surface thereof. A pulley segment set comprises a number of pulley segments [] slidably mounted in the pulley assembly and arranged in a ring concentric with the core pulley []. The pulley segments [] are individually actuatable out of the pulley assembly into an engaging position and into the pulley assembly into a non-engaging position. The pulley segments [] have a second set of mating features [] on an peripheral surface matching the first set of mating features. An endless drive member [] has corresponding mating features on an inside surface for engaging the first and second sets of mating features of the core pulley [] and the pulley segments [] in an engaging position. Contact between the endless drive member [] and a core pulley defines a contact zone [CZ]. An actuator [] actuates the pulley segments [] between the engaging and non-engaging positions when the pulley segments [] are outside of the contact zone [CZ]. One of the pulley segments [] in the pulley segment set is a key pulley segment [] that is positioned relative to the care pulley [] such that when the key pulley segment [] is actuated to the engaging position and rotated into the contact zone [CZ], the corresponding mating features of the endless drive member [] engage the first set of mating features of the core pulley [] and the second set of mating features [] of the key pulley segment [] without the introduction of significant slack or tension.