CARD ADVANCEMENT MECHANISM

摘要

Apparatus for controlling the advancement of punch cards or like sheet material past a plurality of work stations such as may comprise a data recorder used in the preparation and processing of punch cards. Control means are provided to sense the nature of an operation being performed on a particular card as well as the presence of punch cards at other of the plural work stations comprising the system and in response thereto selectively energize the advancement mechanism such that each punch card processed through the system will be advanced at an optimum rate. In the event no punching or printing operation is to take place on the punch card the speed of the advancement mechanism is increased considerably in excess of that which would otherwise enable the advancement mechanism to be accurately stopped. The processing rate achieved by the advancement mechanism is further enhanced by implementing the control apparatus in such a manner that the system may be conveniently shifted from a high speed mode of operation wherein the entire system is dedicated to the processing of a particular card therethrough, to a time-overlap mode of operation wherein the stacking of card n takes place simultaneously with the punching and/or printing of card n+1. A high degree of throughput is achieved in the time-overlap mode of operation by ensuring a continuous feed of punch cards into the card preparation portion of the data recorder thus facilitating the simultaneous printing on two successive cards by the same print mechanism. This latter feature ensures a minimal separation between successive punch cards, which separation is within a fraction of an inch.