Data card reader with magazine - has rotating drum surrounding magazine and containing reader head

摘要

The data cards are stored in a vertical stack, and a selector mechanism releases the required card which then drops down under gravity. The stack of cards is accommodated inside a drum which has its axial horizontal. The drum is perforated with a large number of small holes and rotates, to carry the card past the reader head to the top of the store, whee it is reinserted into the stack of cards. A nozzle connected to a compressed air supply is placed outside the drum, and blows air through the holes to lift the card and press it against the reader head.