Patent GB-785927-A (GB)
Title: Improvements in or relating to record card controlled business machines
IPC: G06K7/016
Filed: 1956-06-06
Abstract: 785,927. Statistical apparatus. BURROUGHS CORPORATION. June 6, 1956 [June 10, 1955], No. 17516/56. Class 106 (1). In a statistical machine of the kind in which punched record-cards 10, Fig. 1, are fed past sensing brushes 16, timing pulses indicative of the position of the card under the brushes 16 are produced by a plurality of sensing brushes CO-09 equally spaced in a line in the direction of advance of the card and a plurality of pulse generating devices each connected to a brush C0-C9 are energized in turn as the brushes are lifted in turn by the leading edge of the card. The brushes CO-C9 normally bear on an earthed plate 18, the card serving to insulate these brushes as it advances. As shown in Fig. 2 each brush (e.g. C0) is connected to a positive source by a resistor 30, a condenser 32 being connected in series with a diode 34 across the resistor and the coil of a relay R0 is connected across the diode. When the brush C0 is earthed to plate 18 the voltage drop across resistor 30 charges the condenser 32. When the brush C0 is lifted by the card, the current ceases and the voltage across resistor 30 falls. Condenser 32 accordingly discharges through the coil of relay R0 which is picked for a short period so that line L0 is connected to the earthed line 40. Relay R0 is arranged to remain picked for a period which corresponds to the time taken for the data sensing brushes to cross the zero index point row on the record card. After the card has passed under the brush CO it again makes contact with plate 18 so that the current flows again and the voltage drop is re-established across resistor 30. This causes condenser to be re-charged through diode 34, the diode preventing the relay being re-energized as the condenser charges. In the form of Fig. 3 the output from the lines L1-L9 (Fig. 2) are connected in common to gates one for each data sensing brush. A sequence of pulses from the relays R0-R9 is sent to the gates at each index point on the card and each sensing brush is connected to the corresponding gate. The outputs from the gates are each connected to a counter. The gates are of the kind normally open but closed by a pulse from the reading brush so that pulses from the timing device are passed to the counters until the brush signal arrives, and are thereafter blocked. The counters therefore record the value of the number in the corresponding column. By reversing the operation of the gates, i.e. causing then to open when a signal is received from a brush, the complement of the number is recorded in the counter. In the form of Fig. 4 there is a storage element for each index point position in three columns to be sensed. Elements S10-S19 correspond to positions 0-9 of the first column and elements S20-S29, S30-S39 to those of the other columns. Each storage element is connected to the output of an And gate G10 &c., the inputs to which are connected to the corresponding sensing brush (e.g. B1 is connected to all gates G10- G19) and to the outputs from the relays R0-R9 (relay R0 is connected to all gates G10, G20, G30). The three columns of storage devices are thereby adapted to record the data of the three columns sensed from the record card.