Patent ID: 9643780
Date: 2017-05-09
CPC Classifications: B65G

Claim:
1. A system for storing and retrieving items comprising: a rack including a plurality of layers, each layer including an aisle and a plurality of rows extending substantially perpendicular from the aisle, the items being storable in storage locations along the rows, each aisle having a loading position at one end and transfer positions located along the aisle adjacent ends of the rows; a shuttle on each layer, at least one of the shuttles being a dual shuttle including a first cart movable along the aisle between the loading position and the transfer positions, the dual shuttle including a second cart configured to be carried by the first cart between the loading position and the transfer positions, the second cart movable in either direction between a transfer position and a storage location along a row while carrying an item; a first cart conveyor located on the first cart operable when the first cart is at the loading position to move the item onto or off the first cart, the first cart conveyor being an endless loop conveyor; a lift substantially adjacent the rack for lifting items to the respective loading positions for the layers, the lift including a lift platform having a lift platform conveyor for moving items off the lift platform and toward the loading positions of the respective layers, the lift platform conveyor being an endless loop conveyor; and each layer of the rack including a rack conveyor adjacent the loading position for transferring items between the lift platform and the loading position, the rack conveyor sized to as to be able to hold at least one item thereon so that the rack conveyor can move items onto one of the lift platform conveyor and the first cart conveyor while the second cart is located in a given row, the second cart being independently drivable off the first cart to perform at least one of placing or retrieving an item in the given row while the first cart moves along the aisle spaced from the given row.