Patent GB-968119-A (GB)
Title: Improved form reader apparatus
IPC: G06K13/08
Filed: 1961-12-14
Abstract: 968,119. Sensing record cards. INTERNATIONAL BUSINESS MACHINES CORPORATION. Dec. 14, 1961 [Dec. 28, 1960], No. 44807/61. Heading G4M. In a record card reading apparatus for reading records bearing instructions, the records are taken in turn from a stack 10 and passed to a gripper drum which carries them past a reading head and means are provided responsive to instructions on the record for releasing the record to be returned to the stack or retaining the record on the drum for re-reading and preventing the next record being fed to the drum. The records 11 are removed individually from the bottom of the stack by a picker 13 and a shoot 14,15 with feed rollers 16- 20 takes them to the drum 22. There are four gripper sets spaced ninety degrees apart on the drum and a sensing station 24 for reading the data (e.g. punched holes) on the record as it is carried past. The solenoid 25 determines whether or not the gripper shall be released to allow,the record to return to the hopper 10 at the lowermost point. The drum circumference is equivalent to 360 card columns. A record card has eighty columns so that there is room for a card in each quarter of the drum and a quarter revolution of the drum constitutes one card cycle. A number of circuitbreaker cams rotate once per card cycle. A frictional drive is applied to the drum and a pair of escapement devices which are alternately energized to allow the drum to rotate in column increments for 80 columns after which the drum moves freely for the next ten column spaces. The feed rollers 16-20 and the picker are driven through clutches which may be disengaged under separate control. The sensing station 24 consists of a bank of twelve star wheels 95 rotatabley mounted on levers 96. Each wheel 95 senses a row of the record so that the records are sensed column by column. A comb of spring blades normally presses the star wheels against the record but this is raised by a cam to allow the grippers to pass. A record card after leaving the stack 10 is forwarded by the rollers 16-19 to the end of the shoot 14, 15 where it is retained by a spring. As a gripper passes the idler roller 21 is moved towards roller 20 by energization of a feed solenoid. The roller 20 advances the record so that its leading edge engages a stop under the open gripper. The grippers are held open or closed by spring loaded toggle mechanisms. The toggle of this gripper is tripped by a stationary stud 117 at this moment causing it to close and hold the record to the drum When the record is to be released the gripper toggle strikes a release stud 124 at the lowermost position to open the gripper and allow the record to fall back into the stack. Friction rollers 26 rotate clockwise to support the greater part of the weight of the cards above a certain level. Card levers are provided on the shoot 14, 15 at CL1, at CL2, CL3 on the drum at CL4 for the reread operation and at CL5 for stacking.  Operation: - The apparatus reads columns 1 and 2 of a card and stores the data in two banks of buffer relays (termed "odd" and "even" relays respectively) and if networks of checking contacts indicate that both colums have an odd number of holes the drum steps to column 3. The relay columns now contain information identifying the rest of the information on the card. The data from the buffer relays is sent to a utilization device which determines whether it is interested in the rest of the data or not. If it is, an answer is produced to read the next two columns in the same way so that, if repeated advance signals are given the whole card is read out in two-column increments. If the utilization device signals that it is not interested in the record, an eject signal is initiated so that the drum is advanced from whatever position it had reached to the column 1 position of the next card. If the utilization device decides that a card still on the drum should be reread e.g. to repeat a series of instructions the release stud 124 is withdrawn by solenoid 25 and the cards re-circulate on the drum. Since the reading station 24 and the solenoid 25 are two  card cycles apart the decision to recirculate a card may be delayed until after the following card is read. By using a bigger drum or feeding the cards sideways instead of lengthwise more cards may be accommodated on the drum and the decision to recirculate may be delayed by a larger number of card cycles. Whenever solenoid 25 is operated to recirculate a card the feed of new cards to the drum is suspended until the last one fed has been carried past the loading point. The original sequence is thereby preserved.