Patent GB-589006-A (GB)
Title: Improvements in or relating to devices for summing numbers algebraically
IPC: G06F7/42
Filed: 1945-03-14
Abstract: 589,006. Calculating - apparatus. BRITISH TABULATING MACHINE CO., Ltd. March 14, 1945, No. 6404. Convention date, March 15, 1944. [Class 106 (i)] A device for obtaining the positive algebraic sum of a plurality of numbers comprises an adding network (Fig. 5e and part 5c), having a set of contacts interconnected between input and output wires in accordance with the table of addition of any two digits, a relay totatiser (Fig. 5c) comprising a set of magnets for each denomination of a number, means for connecting the set of magnets for a denomination to the output wires, means for adjusting the set of contacts of the network to represent a digit, means (Fig. 5f) for setting up a second digit on a group of wires, and for connecting the input wires to the set-up of the second digit, whereby current directed through the network to the totaliser magnets energizes a magnet or magnets of the set to represent the units digit of the sum of the first and second digit. A known type of punching machine is adapted to control the entry of data into the adding device, while corresponding numbers are punched, digit by digit in descending order, in a plurality of fields A, B, C, of a record card 10, Fig. 2. Corresponding denominations in each field are related to a common column selecting'relay (e.g. 4C for " thousands," Fig. 5b), and this relay is energized when a brush 36, moving with the carriage of the punching machine, connects a common strip 38 with the appropriate contact 37 plugged to the relay socket 43. Energization of relay 4C closes two contacts 4Ca, 4Cb, Fig. 5a, in the " thousands " section of a network in which contacts A4a, A4b, ACa ... etc. are controlled by relays Al ... A5, AC, Fig. 5c, in the " thousands " section of the totaliser. By this network, the value represented in the thousands order of the totaliser, on relays A1 ... A5, AC (numbers 6 to 9 being represented as 5 + ... ) is reproduced in a set of relays OP ... 5P, Fig. 5b, the " thousands " order of the totaliser then being cleared. The relays OP ... 5P control contacts in an adding network, Fig. 5e and top L.H. of Fig. 5c, whereby the " thousands " digit, extracted from the totaliser, is added to the " thousands " digit of the number being entered and punched. The depression of the appropriate key, Fig. 5f, energizes a punch selector magnet 19, which pulls down the corresponding key lever of the punching machine and this causes the perforation of the card in known manner. Also, a corresponding relay R20 closes its contacts R20a and a circuit is completed through one of the wires 60 to the adding network, Fig. 5e and 5c. The output wire or wires 61 ... 67 of this network complete the circuits of totalizer relays in the " thousnads " order representing the units digit of the sum of the two digits which have been added. A carry from one denomination to the next is represented by the energization of a special relay AC in the higher denomination, and where the higher denomination already contains a " 9 " (represented by the energization of relays A4 and A5) contacts A4e, A5e are both closed and the circuit to the A.C. relay continues to the next higher denomination to energize a further A.C. relay. The subtraction of a number from the total is accomplished by closing a switch 75, Fig. 5e, whereby relay S is energized to transfer contacts in the network, which now causes the incoming digit to be entered as the nines complement. The " fugitive one " is added into the units order when a transfer from the " tens of thousands order causes the energization of a relay CS. This relay closes the circuit to an A.C. relay in the units order. When the settings of the totaliser relays are transferred to relays OP ... 5P, by the network of Fig. 5a, the A.C. relays control contacts in this network which add in the carried " 1 ". The 'total of the entered numbers is punched on the card, when switches 56, Fig. 5b, and 81, Fig. 5f, are closed, a circuit being completed through a network, Fig. 5f, controlled by relays 5P ... 1P, whereby an impulse passes to the punch selector magnet 19, representing the " tens of thousands " digit of the total. the carriage then steps on to the next lower denomination and so on.