Material handling apparatus with delivery vehicles and recirculation

A method for sorting a plurality of items to a plurality of sort locations, comprising the steps of:

• conveying items from an input area to a loading area;
• scanning the items to detect a first characteristic of the items;
• scanning the items between the input area and the loading area to detect a second characteristic of the items;
• loading each item on an independently operable vehicle that is moveable along a vertical loop of track in an aisle between a first set of sort locations and a second set of sort locations;
• selectively operating the vehicles to direct items to a reject area adjacent the loading area in response to not detecting the second characteristic during the step of scanning the items to detect a second characteristic;
• selectively operating one of the vehicles to raise an item above the height of the input area in response to detecting the second characteristic during the step of scanning the item to detect a second characteristic;
• selectively operating the one vehicle to convey the item to a recirculation path after the step of selectively operating the one vehicles to raise the item, wherein the step of selectively operating the one vehicles to convey the item to a recirculation path is in response to not detecting the first characteristic during the step of scanning the item to detect a first characteristic;
• selectively operating the one vehicle to convey the item to one of the sort destinations after the step of selectively operating the one vehicle to raise the item in response to detecting the first characteristic during the step of scanning the item to detect a first characteristic and detecting the second characteristic during the step of scanning the item to detect a second characteristic;
• and
• conveying the item along the recirculation path toward the input area if the item is conveyed to the recirculation path.

An apparatus for sorting a plurality of items, comprising:

• a group of sort destinations wherein each sort destination is configured to receive one or more items;
• a first track, wherein the plurality of sort destinations are positioned along the first track;
• a second spaced apart from the first track to form an aisle between the first and second track;
• a plurality of delivery vehicles vertically and horizontally displaceable within the aisle for delivering items to the sort destinations;
• an input station comprising a qualification station configured to analyze an item to detect a first characteristic of the item indicative of the sort destination to which the item is to be sorted and a second characteristic of the item;
• a conveyor for conveying items from the qualification station to a loading station where items are loaded onto the delivery vehicles;
• a recirculation path providing a path along which the item can be transported back toward the input station, wherein the recirculation path has an entrance along the first or second tracks such that the delivery vehicles move upwardly from the loading station to reach the recirculation path;
• a reject area positioned adjacent the loading station;
• a controller for controlling operation of the delivery vehicles, wherein the controller is configured to selectively identify items as qualified for delivery in response to detection of the second characteristic and to selectively identify item as not qualified for delivery if the second characteristic is not present,
• wherein the controller is configured to direct items identified as not qualified for delivery to the reject bin;
• and
• wherein the controller is configured to control the delivery vehicles carrying items identified as qualified for delivery so that such delivery vehicles drive upwardly away from the loading station;
• wherein the controller is configured to control the delivery vehicles carrying items identified as qualified for delivery so that such delivery vehicles carrying an item for which the first characteristic is detected are directed to one of the sort locations and delivery vehicles carrying an item for which the first characteristic are not detected are directed to the entrance of the recirculation path and displaced toward the recirculation path.