Segmented pusher control for conveying system

Abstract

An article conveying system of the type having a conveying surface defined by the uppermost ones of a plurality of slats interconnected in an endless web for displacing articles laterally with respect to the conveying surface and including a diverter shoe movably mounted to each slat, includes a system of parallel tracks and diverting gates to independently selectively move one or more diverter shoes laterally while maintaining lengthwise alignment of the selected shoes in order to displace an article without rotation of the article. A control senses both the position of articles and the position of shoes in order to determine the relative spacing between shoes and articles. This allows the control to determine whether a shoe assigned to an article interferes with another article to accommodate article spacing of less than one shoe. Articles may be displaced using only one or two shoes by determining that the shoe is properly positioned with respect to the article. A divert control module maintains a dynamic accumulated article length for the accumulation section of a take-off conveyor based on article-length data received from a central sort controller, spur take-off speed and the time from the most recent divert in order to determine whether an article may be diverted to the associated spur.