Sortation conveyor apparatus and methods

Sortation conveyor apparatus and methods for selectively diverting articles from a primary conveying surface onto branch lines are provided. In one embodiment, the apparatus comprises a control system for selectively operating activating elements. The control system is configured to assign two or more pusher elements to each article to be diverted, and to ensure proper diversion of articles when adjacent articles are spaced apart on the primary conveying surface by a distance which is less than the width of an individual pusher element. In one embodiment, diversion is provided by a single activating mechanism for a plurality of pusher elements per branch destination, and by rotating the article during the initial diverting movement and contact with the pusher elements. In one embodiment, a method comprises assigning memory cells to first and second articles based upon the location of the articles along the primary conveyor, and determining if the second article is to be diverted to the same location as the first article, and if so, assigning the trailing cell assigned to the trailing end of the first article to other than the first article.