AUTOMATIC STORAGE AND RETRIEVAL SYSTEM

A system for storing and retrieving items to and from a storage receptacle which includes a track riding dolly carrying a robotic item handler for inserting and extracting items to and from storage The dolly also carries a multishelved caddy for receiving a plurality of items thereon. The item handler has the capacity to access each of the shelves of the caddy and may execute, under computer control, a selected sequence of item transfers between the caddy and storage during a single passage of the dolly from an on/off load point past the storage receptacle. A multishelved caddy loader queues a plurality of items received from an on-load device independently of the caddy, via vertical repositioning, and performs a bulk transfer of the queued items to the caddy when the caddy is available. A mass offloader device permits the bulk transfer of a plurality of items from the caddy to an offload receiver. A unit offloader sequentially offloads the offload receiver, via vertical repositioning of the offload receiver, onto an offload surface independently of the caddy.