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. An actuator actuates the pulley segments between the engaging and non-engaging positions when the pulley segments are outside of the contact zone. One of the key pulley segments in the pulley segment set is a key pulley segment that is positioned relative to the core pulley such that when the key pulley segment is actuated to the engaging position and rotated into the contact zone, 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.