Patent GB-304599-A (GB)
Title: Improvements in or relating to calculating machines
IPC: G06F7/46
Filed: 1929-01-19
Abstract: 304,599. British Tabulating Machine Co., Ltd., (Assignees of Bryce, J. W.). Jan. 21, 1928, [Convention date]. Multiplying-apparatus.-A machine for multiplying multidenominational factors by the timed electric current method described in Specification 303,062 as for single digit factors, comprises multiplicand keys 31, multiplier keys 40, a commutator 46, two accumulators 13, 14 for receiving the tens and units respectively of the partial products, a denomination-selector 52 and a motor M with the necessary clutches &c. To obtain the complete product a. key 27 is depressed to transfer the amount on accumulator 13 to accumulator 14 which will then show the total. Setting up the multiplicand. By depression of keys 31 in the multiplicand banks, sectors 32, Fig.3<b>, are differentially rotated to position brushes 34<a>, 34<b> on contacts 2 9 and 1-9 wired to brushes 45<a>, 45b, Fig. 3. The brushes 34<a>, 34<b> are connected by wires 36a, 36<b>, 37<a>, 37<b> &c. with the selector 52 to direct the product impulses to the desired denominational elements of the accumulators. Entering the multiplier. When key 40 corresponding with the highest digit of the multiplier is depressed a bail 44, Fig. 3, is advanced to bring brushes 45a, 45b carried by it into engagement with corresponding sections of the commutator 46. At the same time, through an universal bail 41, a contact at 42 is closed to cause energization of a clutch magnet 17 to throw in the adding shaft 18 for one cycle. The remaining multiplier digits are similarly entered in succession. Multiplying commutator 46. This consists of a. cylinder provided with sets of contacts 49a, 49b arranged in accordance with the partial product tens and units digits, the brushes 45a cooperating with the tens digit contacts and the brushes 45<b> with the units digit contacts. The two sets of brushes are wired with the respective multiplicand contacts as already stated so that when the machine operates, currents flow through the clutch magnets 59<a>, 59<b> of the accumulator elements under the timing control of the commutator to enter the desired partial product digits in the two accumulators. Denomination-selector 52. This comprises a drum divided into two portions each having four sections containing contacts 56, 64 arranged stepwise and cooperating with brushes 56, 62 wired in cascade fashion with the various clutch magnets of the accumulators. At each rotation of the commutator 46 a circuit is closed at 68, 69, Fig. 3, to a clutch magnet to cause rotation of the drum 52 through one step to direct the next batch of partial product impulses into the accumulator elements one space to the right. Obtaining final product. The operation of key 27, Fig. 3, short-circuits resistance 48 and substitutes magnet 20 controlling a one-cycle clutch 19, Fig. 1, to cause oscillation of a shaft 22a. This in the known manner takes the reading of the accumulator 13 and transmits it by timed currents to the accumulator 14 which thereupon exhibits the complete product. The entire apparatus may be zeroized by operation of shaft 23.