SYSTEM FOR AUTOMATICALLY STAGING LETTERS USED IN CONNECTION WITH A LETTER SORTING MACHINE

摘要

A storage and retrieval machine comprising a base adapted to move horizontally along a supporting surface, a generally vertical mast supported by the base, a carriage supported for generally vertical movement along the mast, and an extendable and retractable shuttle mechanism supported by the carriage, the shuttle mechanism including an upper plate fixed against horizontal movement relative to the carriage, an intermediate plate which is located below the upper plate and which is supported by the upper plate for horizontal movement relative thereto, a lower plate which is located below the intermediate plate and which is supported by the intermediate plate for horizontal movement relative thereto, and hoops on the lower plate for selectively engaging a load, the shuttle mechanism being operable between a retracted condition wherein the intermediate plate is located directly below the upper plate and the lower plate is located directly below the intermediate plate, and an extended condition wherein the intermediate plate extends outwardly in one direction relative to the upper plate and the lower plate extends outwardly in the one direction relative to the intermediate plate.