Patent GB-1403025-A (GB)
Title: Calculating machines
IPC: G06C15/12
Filed: 1972-09-07
Abstract: 1403025 Multiplication operation in calculating machines ING C OLIVETTI & C SpA 7 Sept 1972 [9 Sept 1971] 41631/72 Heading G4B Multiplication is effected in a 10-key calculating machine by entering the multiplier into the machine pin carriage 11, transferring the multiplier from carriage 11 into storage racks 17, entering the multiplicand into carriage 11 and then, using the normal carriage pin-sensing racks 11a, forming the product in an accumulator (not shown), the orders of the accumulator into which the multiplicand is entered by racks 11a and the number of times such entry is made being determined by a device hwich senses racks 17. Either the multiplier or the multiplicand can include a fraction (e.g. ¢), in which case depression of a ¢-key will enter five (e.g. 5/10) into the corresponding (i.e. lowest effective) order of carriage 11. If the ¢-key is not depressed, a zero is automatically entered into this lowest effective order. In the case of the multiplier, either this five or zero is transferred to the lowest order rack 17a If the multiplier and/or the multiplicand does not include the fraction ¢, multiplication is effected and mechanisms are provided to ensure, amongst other things, the desired aligments of cartiage 11, racks 17 and the device sensing the racks so that for example, a zero-containing lowest order is ignored. If both the multiplier and the multiplicand include the digit half, this is sensed after the entry of both factors and the actual multiplication cycles are blocked. Entry of multiplier.-A normal keyboard (not shown) is used to enter the whole number digits into carraige 11. If the digit ¢ is to be entered, the ¢-key (Fig. 7) is depressed, which through slide 26 and lug 29 causes slide 31 to set the "5" pin in the next carriage order. A lever 38 is also released to clockwise movement by depression of the ¢-key and this is used to prevent the automatic zero entry. In the case of a multiplier not including the digit ¢, non- depression of the ¢ key prevents the clockwise movement of lever 38 and this conditions mechanism (141, 149, 152, Figs. 7 and 10) for making the automatic zero entry when the transfer of the multiplier into the racks 17 is subsequently made. This transfer of the multiplier is made by depressing a key (not shown) to activate a mechanism (220-226, Fig. 7) interconnecting racks 11a and 17. Carriage 11  is returned to its starting position and cleared. Entry of multiplicand into the pin carriage 11 is carried out in the same way as for multiplier entry. Multiplication initiation.-A key (69, Fig. 3) is depressed and (i) conditions a cam-follower linkage (Fig. 8) to engage the totalizer with racks 11 during the ensuing multiplication cycles, (ii) conditions a further linkage (Figs. 2 and 8) to overridge (i) and make the first cycle a non-calculating cycle (totalizers not engaged) and (iii) links the sensing means 41-43 for racks 17 with carriage 11 for shifting therewith during the multiplication cycles. If the multiplicand does not include digit ¢, the automatic zero entry is made during the first, non-calculating, multiplication cycle and the consequent one-step shift of carriage 11 is also made by sensor 43, because of (iii) above, the sensor 43 then registering with the lowest but one order rack 17. A return shift through this one step, to re-align sensor 43 with lowest order rack 17a and to render ineffective the zero automatically entered into carriage 11, is effected by a linkage 92-103. If the multiplicand includes digit ¢, the lever 38 will have turned (as for multiplier entry, above) and through link 89 disables linkage 92- 103, so that the return shift through one step is not effected. Lever 38 also acts through link 83 to free a spring 81, which then tries to move sensor 43 into registry with the lowest but one order rack 17 and succeeds if the lowest order rack 17a holds zero (multiplier did not include ¢). A slide 110 can then move far enough to the left to condition a linkage (onlu partially shown in Fig. 1) to allow the multiplication to proceed. If however, the rack 17a holds the value "5", it blocks the leftward movement of slide 110 and the multiplication cannot therefore proceed. Multiplication.-The multiplicand is entered by racks 11a into the totalizer as many times as the number held in the lowest order rack 17. Each time, the rack is returned one step by sensor 43. When the rack reaches its zero position, the pin carriage 11 and sensor 43 are shifted one step left and the multiplication relating to the next order of the multiplier is then made. If any rack 17 is initially sensed to be at its zero position, a non-calculating cycle is made while moving to the next rack 17.