Patent GB-538607-A (GB)
Title: Improvements in or relating to electric systems for the transmission of statistical data
Filed: 1940-02-05
Abstract: 538,607. Printing-telegraphy. BRITISH TABULATING MACHINE CO., Ltd. Feb. 5, 1940, No. 2239. Convention date, Feb. 3, 1939. [Class 40 (iii)] [Also in Group XIX] Apparatus for transmitting statistical data from a transmitting (Fig. 7) to a receiving (Fig. 7a) station comprises means for generating at the transmitter signals which consist each of an impulse of different characteristic frequency and denoting its datum by the instant it occurs during a constant time interval, a single means (wireless link from transmitter unit 100 to receiver unit 101) for transmitting all the signals to the receiving station and means at the latter to filter the signals according to their frequencies and apply them to different circuits. In reading Hollerith cards electrically at the transmitting station, each card column has allotted to it a particular frequency generated by alternators 111-112 and, the position of the single hole in each column denotes its value. The values related to several card columns are thus transmitted concurrently in the one machine cycle-by imposing the various frequencies on a carrier wave produced by alternator 95-to the receiving station where filters 158 and 159 correlate the various signals to their appropriate adding and printing magnets 58 and 37, which magnets then function in the usual way according to the time in the cycle at which the impulses are generated at the transmtter. Means provided to synchronize the various mechanisms in the two-stations include the alternator 96. The card-feed mechanism at the transmitter, and the counter, printer, and read-out mechanisms at the receiver are of the usual Hollerith form. Synchronizing means.-The driving motors TM, Fig. 7, and TMr, Fig. 7a, of the transmitter and receiver respectively, are energized over circuits G1, 95, 96, S1, 98, 97, S2, TM G4 and G1, 95, 96, S1, 99, 100, 101, 102, 103, 104, S3, TMr, G5. The alternator 95 gives the carrier frequency and the alternator 96 gives the frequency which drives the synchronous motors TM and TMr in synchronism. Card reading and transmitting circuits.-The lower brushes LB reading the card holes form circuits from the appropriate alternators 115, 122 over plug connections 132, 134 and through LB, 143, LCLf, 133, 137, 109, transformer 135, and filter 136 to transmitter 100 where these impulses, of different frequency according to the card column, are radiated on the carrier wave to the receiver 101. From the latter, the impulses pass through filter 145 and transformer 146 to filters 158 or 159 according as the impulses originate from alternators 115-122, or 111-114 respectively. The impulses passing the various individual filters 158 or 159 actuate adding magnets 58-or printing magnets 37-which function in the usual manner according to the instant in the cycle at which each impulse arrives i.e. according to the position of the single hole in the card column. Alternators 125-128, Fig. 7, generate signals of particular frequencies for controlling group number printing (125), resetting (126 and 127), and total-printing (128). The frequecies from these alternators 125-128 pass through filters 139, 149, 148, 138 respectively, Fig. 7a, to actuate the control relays shown below these filters.