Patent ID: 7963383

Claim:
A vertically accumulating storage and retrieval apparatus, comprising a first plurality of substantially vertically spaced shelf assemblies supported by support structure and a second plurality of substantially vertically spaced shelf assemblies supported by support structure; each of said shelf assemblies comprising: a shelf tray for receiving, storing, and discharging containers, the shelves of the first plurality of shelf assemblies being substantially staggered vertically relative to the shelves of the second plurality of shelf assemblies, with the free ends of each plurality of shelf assemblies facing the free ends of the other plurality of shelf assemblies, each shelf being mounted to its respective vertical support for pivotal movement between an upwardly tilted receiving position and a downwardly tilted discharge position; spring biasing structure for urging the shelf to the receiving position; a transfer control operatively connected to the shelf and having a lock position retaining the shelf when a shelf of a next lower shelf assembly is not prepared to receive a container, and a release position allowing the shelf to move to the discharge position under the weight of a container disposed on said shelf when the shelf of the next lower shelf assembly is prepared to receive a container.