Patent GB-614054-A (GB)
Title: Improvements in or relating to calculating machines for performing multiplication
Filed: 1946-07-03
Abstract: 614,054. Calculating-apparatus. BRITISH TABULATING MACHINE CO., Ltd. July 3, 1946, No. 19892. Convention date, July 9, 1945. [Class 106 (i)] A cyclically operable multiplying machine comprises a drum having configurations representing the partial products of all possible multiplier and multiplicand digit factors, the configurations being arranged in sets, each set representing a single digit of one of the factors, means for rotating the drum, two sets of sensing elements adapted to sense the configurations of the drum during its rotation, and a device settable to represent a digit of one of the factors, with mechanism controlled by the said settable device adapted to move either the drum or the sets of sensing elements or both, each in either direction parallel to the axis of the drum, to bring the set of sensing elements into co-operative relationship with the set of configurations representing the digit set on the settable device, whereby the sensing elements of the sets sense the configurations representing partial products of the said digit by all possible digits of the other factor, one of the sets of sensing elements sensing the configurations representing the right-hand digits of the partial products and the other the left-hand digits. The machine performs multiplication by partial products as exemplified in Fig. 14. Thus, in the first line, the result of multiplying 7283 by 4 is split up into LH and RH components, the tens component of each partial product coming under LH and the units component under RH. In the embodiment, the multiplier (e.g. 40068) is set up by positioning brushes 12, Fig. 13, relative to contacts 11. The multiplicand (e.g. 7283) is set up in LH and RH groups of contacts 11, Fig. 13a, by positioning similar brushes 12. The partial products are represented by slots 17, Fig. 11, in a drum 15, one side of the drum bearing representations of the LH (tens) components of the partial products and the other side the RH (units) components. The drum rotates 180 degrees during each cycle, and the slots 17 are sensed by members 27 (see also Fig. 5) which, when pushed into the slots, allow contacts 21L, 21R (see also Fig. 13a) to close. After each 180 degrees movement of the drum, cam means transfers contacts 53a ... d, Fig. 13a, to exchange the functions of 21L and 21R respectively during the next cycle. Normally, the members 27, Fig. 11, are positioned to co-operate with those slots 17 in the drum representing multiplication by " 5." In order to multiply by any other digit from 1 to 9, the drum 15 may be moved one step (equivalent to one denomination) to either right or left (indicated by 32), and also the set of members 27 may be moved right or left by a step equivalent to three denominations (indicated by 33); various combinations of these movements enable any of the other digits to be selected. The movements are controlled by a pair of magnets 40R, 40L, Figs. 2, 7 and 13, for the drum, and a further pair 49R, 49L for the set of members 27. A pair of discs 20R, 20L, Figs. 2 and 7, comprising cam surfaces 46 are acted upon by one or the other of two interposers 47 when one of these is projected into the path of a cam surface by operation of magnet 49L or 49R, and cause axial movement of a bar 23 supporting the members 27 (see Fig. 5) to the extent of three denominations. Another pair of discs 35R, 35L co-operate in a similar manner with interposers 37 to move the drum 15 axially one denomination. Immediately after these relative movements have been completed, teeth 60 on the drum engage complementary teeth integral with the bar 23 to prevent any further displacement during the sensing of the drum by members 27. The drum 15 and bar 23 are subsequently restored to their normal positions by fixed cams 47a. Column shift mechanism, Fig. 10, under control of a cam 65 rotating with the drum 15, comprises four relays 73 (see also Fig. 13) adapted to limit the rotation of a member 71 driven by a rack 66 following the cam 65. The member 71, rotating with a shaft 69 carrying a commutator arm 81 (shown diagrammatically in Fig. 13) co-operating with contacts 83, is stopped after one degree of movement if relay 73 (1) is operated, after two degrees of movement if relay 73 (2) is operated, and so on. If none of the relays 73 (1 ... 4) is operated, the member 71 and arm 81 complete five degrees of movement. Also controlled by this device are contacts 87 (LH and RH), Fig. 13a, relative to contacts 88. Operation. The multiplication shown in Fig. 14 is used as an example. First, a key 92 is operated to provide for column skipping where zeros occur in the multiplier; in this case relays R2, R3 become energized through the brushes 12 at the zero position in the TH and H denominations. The drum begins to rotate and contacts C1 close to complete a circuit from line 93 to line 97 (TTH), through brush 12 at the " 4 " position, and through relay 40R to set the drum 15 into the position for multiplication by " 4." As the drum continues to rotate and the members 27, Fig. 5, pass into slots 17 closing contacts 21L, 21R, Fig. 13a, current passes through a contact-breaker C3 at e.g. the " 8 " time in the cycle, through contacts 21R (7 and 2) (the multiplicand digits giving rise to " 8's " in the partial products) through corresponding brushes 12 in the RH network, to the adding magnets 13 in the 7th and 8th denominations. The remaining digits 3, 2 and 1 are added in a similar manner. The magnets 13 form part of a known type of totalizer such as that described in Specification 485,103. Left- and right-hand partial products are totalled separately, the results being added together later in known manner. When contacts C4, Fig. 13, close towards the end of the first cycle, contact 81 has been brought into engagement with contact 83 (1) and therefore relay R1 becomes energized. Thus, when contacts C1 close again during the second cycle, the transferred contacts R1c, R2c, R3c direct current to relay 73 (4) to set the drum in accordance with the multiplier digit in the T denomination.