Patent GB-629621-A (GB)
Title: Improvements in or relating to record card controlled calculating machines
IPC: G06F7/42
Filed: 1946-12-18
Abstract: 629,621. Statistical apparatus. BRITISH TABULATING MACHINE CO., Ltd. Dec. 18, 1946, No. 37311. Convention date, Dec. 21, 1945. [Class 106 (i)] In a record card controlled calculating machine, a denomination unit of a decimal accumulator is characterized by two sets of five relays each, the relays of each set representing respectively the values 1, 2, 3, 4 and 5, means for energizing selectively relays of each set to represent a digit in the 1-5 code, a set of five result relays for recording a denomination of the result, means controlled by the 1 to 4 value relays of the first two sets for determining whether the sum of the values on these relays exceeds 4, means controlled by the last means and by the 5 value relays for entering the 5 into the result relays when the digit of the result to be entered contains a 5 alone or in combination and means controlled by the 1 to 4 value relays for entering digits 1 to 4 in the result relays when the digit of the result to be entered contains one of these digits alone or in combination. In the described embodiment two sets of five translator relays TRA, TRB for two numbers to be added, controlled by timed cam contacts C5 (Fig. 1, not shown), are energized at appropriate times during card sensing so that when a circuit is completed at the sensing brushes 2, 3, Fig. 2, current is directed to the relays R7 which, alone or in combination, represent the numbers sensed from the card. A holding circuit is established in each case, and the energized relays R7 (distinguished according to the two numbers as R71, R72 in Fig. 3) control series of contacts forming adding networks. The result of the addition (AŒB) is represented on denominational sets of five wires each 10, the 1 to 4 wires being selected by the GROUP 1 network. Control of the energization of the " five " wire depends on the GROUPS 2 and 5 networks ; GROUP 2 determines whether the sum of the coded relays excluding the " five " relays totals five or more-in which case a relay R9 is energized and current will be passed to the " five " wire of the set 10 if both or neither of the relays 5 in GROUP 5 are energized. If only one of the relays 5 is energized the current passing through the GROUP 2 network passes through GROUP 4 to a transfer wire 9 which energizes a relay C to add " one " in the GROUP 1 network of the next higher denomination. If only one of the relays 5 is energized and a circuit through GROUP 2 is not completed, current from wire 7 passes through GROUP 5 and the R9 contacts (at rest) to the " five " wire of the set 10. GROUP 3 network is provided to cater for' '' long transfer (i.e. transfer to a register already standing at " 9 " and thus giving rise to further transfer). In the case of the units denomination it is redundant. The transfer wire 9 is connected to the GROUP 3 network of the higher denomination which network completes a circuit when the 1 to 4 relays that are energized represent a sum of four or more. In such a case the relay 9 is energized representing a five as previously described: Where the second number B is negative and the equivalent of subtraction is to be performed, a special hole in the card is sensed by a brush 11, Fig. 2, causing energization of a relay SR. This relay controls the adding in of one in the units denomination by completing the circuit of the relay C of GROUP 1, and also suppresses the transfer from the hundreds nomination by opening the circuit of the wire 9H. The output wires 10 from the adding networks lead to result relays from which by means of a series of cam-controlled contacts timed impulses representing the result govern printing or punching magnets.