In a conveying system for conveying small articles such as cassettes or pallets, it is frequently necessary to remove the articles from the conveyor for processing. Traditionally, an operator has manually gathered the articles as they pass along the conveyor, and manually stacked the articles in preparation for transporting to the processing equipment. The manual gathering and stacking of the articles requires considerable labor and is a substantial cost factor.
Automatic stacking mechanisms have been proposed in the past, such as shown in U.S. Pat. No. 3,470,996. In the stacking mechanism, as shown in the aforementioned patent, articles on a conveyor are pushed laterally by a pusher unit from a conveyor to a position beneath a stacking chute. A lift cylinder then operates to elevate the article upwardly into the chute and the elevated article is then held in the chute by a second plunger which is located opposite the pusher assembly. While devices of the type shown in the aforementioned patent can serve to stack articles one on top of each other, the mechanism requires that the articles slide against each other during movement from the conveyor to the stacking chute and this can cause substantial damage and scratching to the articles, if they are of a delicate nature.