Patent GB-454249-A (GB)
Title: Improvements in or relating to calculating machines
IPC: G06F7/46
Filed: 1935-03-26
Abstract: 454,249. Calculating - apparatus. CAMPBELL, C., and BRITISH TABULATING MACHINE CO., Ltd., Victoria House, Vernon Place, Southampton Row, London. March 26, 1935, No. 9441. [Class 106 (i)] A method of dividing a number entered into a calculating mechanism by a second number of the form 2n x 3 consists in automatically performing the following operations in any predetermined order, namely, n halving operations, the addition of the quotient resulting from one of the halving operations to its dividend and division by nine by entering each digit of the dividend into each denomination, lower than its own, of a counter. Arrangements of calculating mechanism adapted to operate in accordance with the method are described. In one form as shown in Fig. 2, the mechanism comprises three counters of the kind normally used in Hollerith tabulating machines each being controlled by electromagnets 10. Counters 2, and 3 have normal reading-out mechanism N of the conventional commutator type while counters 1 and 2 have halving reading - out mechanism H whereby half the amount can be read out. This halving mechanism is similar to that described in Specification 437,578. The controlling circuits and operating relays are shown in Fig. 3. The amount to be divided is entered in a known manner into counter 1 and the division operation is initiated by energizing relay C which closes contacts C-c to provide a circuit on the closure of cam contacts CC-2 through relay coils 1CR, 2CR. These relays operate their contacts 1CR1-7, 1CR-8, and 2CR1-7, 2CR-8 so as to connect the reading-out mechanism of counter 1 to the operating magnets 10 of counters 2 and 3 whereby one half the amount is entered into these counters. On the closure of cam contacts CC-3 and the closed contacts 2CR-8 a relay 1Y is energized which opens contacts 1Y-b and closes contacts 1Y-c so that when the contacts CC-2 again close the relay 3CR is energized and closes its contacts 3CR1-8, 3CR-9, and 3CR-10 so as to connect the reading-out mechanism of counter 2 to the operating magnets of counter 3. The next closure of the cam contacts CC-3 through the closed contacts 3CR-9 energizes the relay 2Y which opens contacts 2Y-b and closes contacts 2Y-c. The following closure of cam contacts CC-2 energizes relays 1R, and 2R, which operate the reset clutch mechanisms of the counters 1 and 2, to restore them to normal zero position. During the next four cycles the amount in counter 3, which is three-quarters of the amount originally entered in counter 1, is divided by nine by repeated entries into counters 1 and 2, the entry into counter 2 being one denomination lower than into counter 1 and both entries in each subsequent cycle being two denominations lower than the corresponding entry in the preceding cycle. These operations are initiated by a cam associated with the reset mechanism of counter 1 closing contacts 1RC and completing the circuit through a relay 3Y to close contacts 3Y-c so that a column shift relay 1CS is energized when the contacts CC-2 next close. The relay 1CS closes its contacts 1CS-2-9 and 1CS-10-16, thereby connecting the lines 23 from the reading-out mechanism of counter 3 to the operating magnets of counters 1 and 2. The connections are such that the amount entered in counters 1 and 2 are one tenth and one hundredth respectively of the amount in counter 3. During the next cycle relay 2CS is energized to close contacts 2CS-2-7 and 2CS-8-12 and the amount in counter 3 is again read out and entered into the appropriate denominations of the counters 1 and 2. The relays 3CS and 4CS are then operated in succession to close their contacts 3CS-2-5, 3CS-6-8, 4CS-2-3, and 4CS-4, whereupon the amount is successively read-out and entered in counters 1 and 2. During the next cycle the relay 4CR having been energized to close contacts 4CR-1-7 the amount in counter 2 is transmitted to counter 1. The energization of relay B follows and the amount in counter 1 may be printed or otherwise utilized for a subsequent calculation. Relay B closes contacts B-1 and B-2 so that on the next cycle the reset magnets 1R, 2R and 3R are energized to restore the three counters. Relay B also opens its contacts B3 to de-energize the coil C to restore the circuits to normal. If the digits in the two highest denominations of the amount entered in counter 3 are zero one cycle may be eliminated by short circuiting the relay 4CS by providing a reading out mechanism comprising a zero contact 46, segments 47, and brushes 48. In an alternative arrangement shown in Fig. 5, half the amount in counter 1 is entered into that counter and half the resulting dividend is then divided by nine, the control circuits being modified accordingly. In another arrangement shown in Fig. 6, the number is first divided by nine, the quotient obtained is halved and added thereto and the result again halved, the control circuits being again modified. Specification 436,163 also is referred to.