Mail sorting.

摘要

A method is disclosed for sorting a set of mail items according to a predefined delivery sequence, the method comprising the steps of: generating for each of a first subset of the mail items a first sequence number according to the position of their respective destination addresses in the delivery sequence; sorting, using a sorting machine, the first subset into batches according to the first sequence number disregarding a number N of the most significant digits thereof; associating with each of a second subset of the mail items, one of the first sequence numbers corresponding to the destination addresses of the mail items in the first subset between which their respective destination addresses lie in the delivery sequence; generating for each of the second subset, a second sequence number according to the position of their respective destination addresses in the delivery sequence among the destination addresses of mail items in the second subset associated with the same first sequence number; sorting, using a sorting machine, the second subset into batches according to the second sequence number and the first sequence number disregarding N of the most significant digits of the first sequence number; interleaving the batches of mail items from the first subset and from the second subset; and sorting the mail items according to the N most significant digits of the first sequence numbers. In this way, all the mail is sorted in sequence, but sorting of the mail can begin prior to all the mail being physically present at the sorter or its location in the sorting scheme being known.