Patent ID: 7240781

Claim:
A positive displacement sorter, comprising: a conveying surface traveling in a travel direction; a plurality of pusher shoes capable of traveling laterally of said conveying surface travel direction, said pusher shoes having article-contacting members extending at least partially above said conveying surface to displace articles on said conveying surface, corresponding portions of said pusher shoes being generally separated from each other in said travel direction by a shoe pitch; a plurality of diverter rails extending generally diagonally under said conveying surface and a plurality of actuators associated with said diverter rails, said actuators selectively directing pusher shoes onto corresponding diverter rails to divert ones of said pusher shoes and thereby displace an article; and a control, wherein corresponding portions of said actuators being separated from each other by more than said shoe pitch; wherein said control capable of controlling said actuators in a manner that selectively diverts at least two of said pusher shoes that are spaced apart from each other by more than said shoe pitch when actuated; wherein said plurality of diverter rails configured to cause one of the at least two of said pusher shoes to catch up with another of the at least two of said pusher shoes in said travel direction, wherein said at least two of said pusher shoes are substantially spaced apart by no more than said shoe pitch when displacing an article.