Transferring letters singly from pile - using banks of photoelectric cells to control progress of letters between pairs of continuous belts

摘要

The letters are placed in a pile (1') in the machine, the uppermost contacting the underside of a continuous belt (25). This top letter is picked up by the belt and moved horizontally between a pair of continuous belts (48, 49) placed next to the pile. The letters are conveyed for further processing. Underneath the belts are banks (71, 72, 73) of photoelectric cells. These are connected into a control unit (60) containing a logic circuit and controlling operation of the belts. As each leading or trailing edge of a letter obscures these cells, belts are energised to ensure correct spacing of the letters.