Patent GB-902672-A (GB)
Title: Improvements in or relating to multiplier accounting machine
IPC: G06F7/46
Filed: 1959-03-24
Abstract: 902,672. Digital electric-calculating apparatus. BURROUGHS CORPORATION. March 24, 1959 [March 31, 1958], No. 10191/59. Class 106 (1). An electro-mechanical multiplying apparatus comprises a source supplying digit-indicating signals on separate channels, function table switch means settable in accordance with a multiplier digit to connect multiplicand digit channels to the digit signal channels representing in each case a digit of the partial product formed by the product of the multiplier and multiplicand digits concerned, multiplicand switch means set in accordance with the multiplicand and connecting the multiplicand digit channels to denominational channels in dependence on the multiplicand digits set in the different denominations, and columnshifting arrangements connected between the denominational channels and an accumulator. The embodiment described employs an accumulator 13, Fig. 1, as disclosed in Specification 902,671, in which the accumulator wheels are frictionally driven and arrested at differential times under the control of digit signals of varying length derived from a " pulse generator " comprising cam-controlled switches operated synchronously with the accumulator shaft. The multiplying apparatus is adapted for connection to a key-set mechanical accounting machine such as that described in Specification 709,181 and includes two switch assemblies 11, 12 settable by means of coded projections 17a on extensions 17 of the differential actuators of that machine. The switch assemblies 11, 12 receive the multiplier and multiplicand respectively. When the product has been formed in the accumulator, it is transferred via the extensions 17 to the accounting machine. Multiplication.-The function table switch means is in two parts, one for the right-hand partial product digits and one for the left-hand. The table is first set according to the lowest order significant multiplier digit, then first the right-hand digits of the partial products of this multiplier digit and the multiplicand digits are entered in the accumulator, followed by the left-hand digits. This procedure is then repeated for the higher order multiplier digits in sequence. The multiplier unit 8 comprises two function table discs 50, 128, Fig. 1A, for the right-hand and left-hand partial product digits respectively and right-hand and left-hand shifter discs 62, 73 for column-shifting purposes. The discs are positioned by the selective engagement of individual electromagneticallycontrolled clutches 19A-19D and bear printed circuits which are sensed by contactors 125, 122 on a " platen " 123. The latter is moved by cams 146, during each multiplier digit cycle, from the central ineffective position shown first to engage the contactors 125, 122 with the righthand function and shifter discs 50, 62, then to engage them with the left-hand function and shifter discs 128, 73, and finally back to the central position. Setting the function table and shifter discs.- For setting purposes, the outside surface 52, Figs. 1A and 15, of the right-hand function disc 50 is printed with various isolated contact areas 53a, 53b, &c. over which move contactors for the digits 1-9 and common return contactors 55, 56. The contactors are in circuit with the clutch associated with the disc and the common digit leads 15, Fig. 29, of the multiplier switch assembly 11. The latter has in effect ten digit switches for each of twelve orders, a switch being closed in each order corresponding to the digit set in that order so as to connect a lead 14 for that order to the corresponding digit lead 15. Each order has additionally a switch 160 which remains closed only if the order registers zero. Initially, the lowest order lead 225 is marked and the signal is passed to the switch of the lowest significant digit, as shown 4 in the third order, and from there to the corresponding contactor 54A, Fig. 15, and via the contact surfaces to the clutch to cause the disc to be set to position " 4," at which point the clutch circuit is broken. An auxiliary disc 58, Fig. 1A, is carried by the same shaft as the disc 50 and bears contact surfaces engaged by a contact spider arranged so to control the clutch for the left-hand function disc 128 that it also assumes a position corresponding to the multiplier digit. In a similar manner, the right-hand shifter disc 62 is caused to move, to a position corresponding to the order containing the lowest significant multiplier digit, under the control of the zero switches 160. In Fig. 29, the outside selector surface of this disc 62 and its co-operating contactors are diagrammatically represented as a simple rotary selector switch 164 under the control of the clutch solenoid 42A. Again, an auxiliary disc 72 is driven with the disc 62 and the left-hand disc 73 is caused to follow up. These setting movements occur with the platen 123 in its central position; after it has moved away from the right-hand discs towards the left-hand ones, the right-hand discs are repositioned for the next higher multiplier digit. For this purpose, the right-hand shifter disc clutch is pulsed by the timing circuits to advance the disc one step. If, however, the next zero switch 160 is closed, further steps will follow until an order containing a digit other than zero is reached whereupon the open zero switch 160 for that order will cause the clutch to be de-energized. For the purpose of re-positioning the right-hand function disc, the left-hand shifter disc 73 has contact areas on its outer surface 109, diagrammatically shown in Fig. 29, engaged by contactors connected to the leads 14 of the multiplier switch assembly 11 for orders 2-12. By this means, when the left-hand shifter disc is in one position, it applies a signal to the next multiplier order to permit the right-hand function disc to be repositioned in accordance with the multiplier digit in that next order. Interlocking and timing circuits, Fig. 31 (not shown), ensure that the clutches operate in the correct sequence and in the proper relationship to the accumulator and platen-shifting operations. Selecting denomination under control of the paper carriage.-The multiplier and multiplicand switch assemblies each have twelve orders and the accumulator has twenty and the particular orders of the accumulator in which the product is formed may be varied. As described above, the right-hand shifter disc 62 is first set so that the first right-hand partial product digit (the units digit of the product of the lowest order multiplier and multiplicand digits) is entered into the lowest order of the accumulator. However, by marking contactors W-Z, Fig. 20, on the selector face of the disc 62, the disc may be shifted a further 2, 5, 7 or 8 column steps. The contactors W-Z are marked by means of a switch, Fig. 33 (not shown), the arm of which is moved by an electromagneticallycontrolled mechanism for sensing the presence, and length, of a control projection in the paper carriage programme unit of the accounting machine. To allow for this denominationselection, when re-positioning the right-hand function disc under the control of the lefthand shifter disc, the outer surface 109 of the latter is also engaged by contactors, Fig. 22 (not shown), marked by the carriage-controlled switch. Function, table discs.-The inner surface 57 of the right-hand function disc 50 is shown in Fig. 16. It is divided into segments each corresponding to a multiplier digit, one of which is effective at any time. The effective segment is sensed by nine contactors 125a which engage the radial contacts P and are connected to the nine digit channels of the pulse generator, and nine contactors 125b which engage the contacts M within the segment and are connected to the digit leads of the multiplicand switch assembly. The printed circuits connect each M contact to that P contact corresponding to the units digit of the product of the corresponding multiplicand digit and the multiplier digit associated with that segment. The circuit-paths thus established, in the case in which the multiplier is four, are shown diagrammatically in Fig. 35. In this example, forty-seven is set in the multiplicand switch assembly so that the only complete circuits established are from the digit channels 6 and 8 to the denominational channels for the fourth and third orders respectively, 6 being the right-hand partial product digit for 4x4 and 8 for 4 x 7. The 6 and 8 digit signals are then applied via the right shifter disc 62 to the accumulator 13; the circuit for the 8 digit signal is shown in Fig. 30. The left-hand function disc 128 is similarly formed to embody the left-hand partial product digit table. Shifter discs.-The inner surface 66, Fig. 21, of the right-hand shifter disc 62 has twelve concentric rings of input contacts engaged by contactors 122, Figs. 1A, 26 and 30, connected by leads, e.g. L-3, Fig. 30, to the denominational leads of the multiplicand switch assembly 12. The concentric rings are connected to an outer ring of output contacts, e.g. OP-3, engaged by a ring of twenty contactors 122 connected by leads, e.g. OL-3, to the twenty orders of the accumulator 13. The relationship between the output contacts of the disc and the twenty contactors depends on the angular position of the disc. The left-hand shifter disc is similar, but is arranged to be effectively one step ahead of the right-hand disc. Round-off.-At the completion of the multiplication, the shifter discs complete circuits for rounding off by adding 5 in a selected order and zeroizing the lower orders in the manner described in Specification 902,671.