Patent GB-454247-A (GB)
Title: Improvements in or relating to calculating machines
IPC: G06F7/46
Filed: 1935-03-26
Abstract: 454,247. Calculating - apparatus. CAMPBELL, C., and BRITISH TABULATING MACHINE CO., Ltd., Victoria House, Vernon Place, Southampton Row, London. March 26, 1935, No. 9439. Drawings to Specification. [Class 106 (i)] An apparatus for converting an amount in pence into an amount in the sterling rotation comprises in combination mechanism for dividing the amount by twelve to convert it into a decimal amount in shillings correct to two places of decimals, or by two hundred and forty to convert it into a decimal amount in pounds correct to three places of decimals, and mechanism for converting the decimal amount into the equivalent amount in the sterling rotation. The invention is described as applied to a record card controlled multiplying machine as described in Specification 405,031, and the electrical circuits are generally similar to those described in Specification 436,163. The machine is provided with seven accumulators; the first accumulator has five denominations which serve as a multiplier register and four denominations as a multiplicand register. Two accumulators are employed for summing the partial products ; two other accumulators sum the partial quotients resulting from the division by twelve. The sixth accumulator is one in which the final product is obtained as a sterling amount and incorporates means for dividing the amount thereon by twenty similar to that described in Specification 436,163. The last accumulator sums a series of products and is used for checking purposes. The record cards are fed from a supply magazine between reading brushes which read the factors and enter them in the multiplier and multiplicand registers, the card is then fed to the punching section of the machine. The multiplication process is performed by circuit arrangements as described in Specification 358,105 and the right and left-hand partial products are entered in their respective accumulators and then the right-hand amount is transmitted to the left-hand accumulator. The machine is now ready to divide the integral part of the product by twelve ; for this purpose the reading-out mechanism of the left-hand accumulator is connected by sets of relays and contacts to the operating magnets of the accumulators registering the partial quotients which quotients are then added by transmitting the right-hand amount into the left accumulator. This amount in shillings is then divided by twenty in a manner similar to that described in Specification 436,163 and the machine is ready to punch the result on the card. The lowest denomination of each of the partial quotient accumulators operates on the nonary notation so that the recurring decimals are added to give the correct result as vulgar fractions 0/9, 3/9, and 6/9. If a card already containing a product, is passed through the machine the multiplication and punching will be rendered ineffective, but its product will be added to the summation accumulator. The pounds and shillings digits are entered directly but the pence digit is entered through a pence translator. In a modification the product in pence is divided by two hundred and forty by altering the contacts and circuits of the dividing relays. The machine may be modified to divide the multiplicand by twelve or two hundred and forty and subsequently to multiply this quotient by the multiplier. The reading-out mechanism of the multiplicand register is arranged to control the division relays. The machine may also be adjusted to multiply an amount in shillings and pence by a number by entering the shillings portion directly into the left quotient's accumulator and the pence portion into the multiplicand register. Division by twelve may also be effected in the manner described in Specification 454,249, that is, by providing the multiplicand register with a reading-out mechanism by which half the multiplicand can be read out. The halving mechanism is similar to that described in Specification 437,578. The machine operates to obtain three-quarters of the multiplicand and to multiply this amount by i which is equivalent to dividing by nine. Specifications 413,327 and 454,248 also are referred to.