Patent GB-155329-A (GB)
Title: Improvements in and relating to methods of summation in card tabulating and statistic-compiling machines
Filed: 1919-08-14
Abstract: 155,329. Tallmadge, C. H. Aug. 14, 1919. Statistical machines. - Comprises a method of subtraction in cardtabulating and statisticscompiling machines, in which one face of a punched card is presented to the card-reading elements for ordinary addition, while the reverse face is presented for subtraction by complemental addition. The ordinarv Hollerith card if punched to represent a number in the usual way, reversed, and lowered two rows, would, if placed against the reading field, expose the co-digital of the number. The only modification necessary in the ordinary machine is, according to this invention, to provide an additional card rest, two rows lower than the usual rest, and means for moving one rest out of use while the other is in use. Instead of this a card may be used with the figure field displaced towards the top of the card, so that when reversed, the codigital is added. Figs. 7 and 8 show an equal margined card, which when reversed causes the codigital to be added. In all these forms, an additional counter is required to add unity for each card passed in a reversed manner through the machine, to give the true complemental. A card may be marked negative and punched a unit short of the desired number, such when reversed adding the true complemental. Fig. 11 shows a card punched in two columns. In the main column the number to be added is punched, while in the supplemental column the complemental of unity is punched. When passed through the machine in the ordinary way the number in the main column is taken notice of, while a contact through the hole 60 cancels the supplementary column. When reversed, the codigital is added in the main totalizer and unity in the supplementary totalizer. A card may be dually punched in a column, and when passed through the machine either direct or reversed would cause the number of its complemental to be added since the Hollerith tabulator takes notice of the lower punch mark only in any column. Means for effecting dual punching is shown in Fig. 25. The spring punches 88 are operated by lugs 90 on the usual key levers 83 pivoted at 84. A special key 92 is provided which when operated pushes forward a series of horizontal fingers 96 between the lugs 90 and the punches. Each finger 96 overlaps a punch and the next lower punch, so that on a depression of any key after depression of the key 92 two punchings are made in the card. To provide for the subtraction of a number ending in " 0," a separate tabulator for negative cards is used in which the units column is moved up one, " 1 " being opposite " 0 " in the tens column, " 2 " opposite " 1 " and so on, a contact " x " in the units column being opposite " 9 " in the tens column so that when this contact is used 10 is added to the units or 1 to the tens wheel on the totalizing counter. This may be effected with the ordinary tabulator by introducing a, multiple switch as shown in Fig. 23. The 0, 1, 2 &c. leads are connected to actuators 0, 1, 2, &c. of the totalizer wheel through levers 65. When a number is added complementally the switch is moved to connect lead 0 to actuator 1 &c. and lead 9 to actuator 10 corresponding with the contact x described above, as shown in dotted lines.