Patent ID: 8796577

Claim:
A sorting system for postal mail, comprising: a plurality of input sections capable of operating in parallel, each including a feeder that takes in mail pieces one at a time and a scanner that scans each mail piece for destination indicia; a plurality of stackers each comprising at least one row of pockets in which mail is stacked; a routing section effective to route mail in accordance with a sort scheme from any input section to any pocket of a stacker, which routing section includes: first conveyors which transport singulated incoming streams of mail pieces away from each of the input sections, a merge section which receives singulated incoming streams of mail from the first conveyors and merges mail pieces from such singulated incoming streams of mail into outgoing streams each containing mail pieces destined for one or more rows of stacker pockets as determined by the sort scheme, the merge section including second conveyors which receive the incoming streams of mail pieces from the first conveyors, refeed chutes positioned in the second conveyors to receive mail pieces which must be removed from the merge section, first diverts in the first conveyors positioned to selectively divert mail pieces to a second conveyor based on the sort scheme, second diverts positioned in the second conveyors to selectively divert mail pieces to a refeed chute, merges positioned in the second conveyors to merge mail pieces into an outgoing stream on a second conveyor, and detectors which detect when a mail piece is in position to be diverted by a divert; third conveyors which transport streams of outgoing mail pieces from the merge section to the rows of pockets of the stackers; and a control system that determines a destination pocket in the stacker for each mail piece based on the sort scheme and the destination indicia read by the scanners of the input sections, and which operates the first diverts to create the outgoing streams of mail according to the sort scheme while operating the second diverts associated with refeed chutes when the control system determines that a mail piece entering a merge cannot be merged into an outgoing stream, due to a merge conflict with another mail piece wherein the second conveyors are arranged in pairs each ending in a merge of the pair to create one of the outgoing streams that is conveyed by a third conveyor, and each second conveyor includes multiple merges along its length at which it receives mail pieces from different first conveyors, and each of the first conveyors contains diverts whereby mail pieces on that first conveyor can be diverted to a second conveyor of each pair.