Patent GB-385829-A (GB)
Abstract: 385,829. Calculating-apparatus. OLIVETTI & CO., Ing., C., Ivrea, Italy. April 29, 1932, No. 12387. Convention date, May 23, 1931. [Class 106 (i).] A machine for the four rules wherein the multiplication of a multiplicand by a single digit of the multiplier is effected in a single operation comprises mechanism for transmitting successively to a laterally movable totalizer the values of the single elementary products which values are obtained by effecting displacements proportional to the sum of the numbers forming the terms of a series, the position of which terms in the series depends on the value of the digit of one factor and the total number of which terms depends on the value of the digit of the other factor. The elementary product A.B may be written in the form A.B = 2B (A/2 - p) + (A/2 + P) which expresses the sum of a number of terms, viz. 2B, of an arithmetical series whose first and last terms are A/2 - p, and A/2 + p respectively. The fundamental series chosen is -0À75, -0À25, 0À25, 0À75, 1À25, ... and since the number of terms in the above equation is even, viz. 2B, it is possible to obtain a derived series from the chosen series by adding and subtracting a value from consecutive terms, which series, although not arithmetical, is adapted for use for effecting multiplication. Such a derived series is formed from the integers, viz. -2, -1, - 1, 0, 0, 1, 1, 2, 2, 3, 3, &c., and is obtained by subtracting from and adding to the terms of the chosen arithmetical series the value À25. The apparatus described is based on the use of that part of the series embracing the terms 0, 1, 1, 2, 2, 3, 3, 4, 4, 5. The units term U of the elementary products is obtained from the sum of a number of these terms and the tens term D is determined from the equation D=A+B- 10 D being O when A + B = or < 10. The elementary product may then be expressed as A.B. = U + 10D. The apparatus comprises two sets of templates 1, 5 with steps arranged in the manner shown in Figs. 1 and 2 and controlled as to extent of their movement by slide bars 3, 7 engaging Archimedian spiral grooves in setting discs 2, 6. The multiplicand is set by means of levers 16, Fig. 23, attached to the discs 2 which are thereby rotated through 9‹ for each unit of movement to effect the displacement of the slide bars 3. To each disc 2 is secured a partially toothed disc 14 and a bevel gear 15, Fig. 24, which latter gears with the planet pinions 18 on a lever 19 secured to the shaft 23. The pinions 18 on the other side gear with a bevel gear 17 secured to the corresponding setting disc 6 so that on the setting of each disc 2 the corresponding disc 6 is reversely rotated to a similar extent to displace its slide bar 7. The multiplier is set by means of levers 35, Fig. 28, through the known form of cam disc and pin wheel mechanism 36 to project the appropriate number of teeth into the path of a wheel 42 secured to the spindle 23. When the shaft 25 is rotated a movement of 9‹ is imparted to the shaft 23 for every unit in the multiplier digit and is transmitted through the arms 19 and planet pinions 18 to the setting discs 2, 6 the movement being through the same angle and in the same direction, thus modifying the position of the slide bars 3, 7. To each template 1 is secured a gear wheel 9, Fig. 24, and to each template 5 are secured the axle pins of planet gears 10 which mesh with the gear-wheel 9 and with the internal teeth of a toothed ring 11. The operation of the machine is effected by the forward and backward stroke of a hande secured to a hub 43 loose on the main shaft 24. To the hub are fixed mutilated wheels 37, 38, Figs. 26, 27 and 28 ; in the normal position the teeth of the wheel 37 engage with a wheel 41 keyed on the shaft 25 so that on a forward movement of the handle motion is transmitted to the shaft 23. During this movement if the sum of the digits of the multiplicand and multiplier in any one denomination is greater than 10 the teeth of the disc 14, by reason of the angular movement imparted to the disc 2, engage those of a corresponding gear wheel 31, Fig. 25, and transfer the tens past D of the product through the transmission pinions 32, 33 to the totalizer drum 34 of next higher denomination. On the continued forward movement the teeth of the wheel 37 leave the wheel 41 and the wheel 38 through a pinion 39 drives a wheel 40 secured to the shaft 24. This shaft 24 carries arms 27 which bear against pins 12, 13 projecting from the templates 1, 5 under the action of springs 28. On rotating the shaft 24 the templates are caused to follow the movement of the arms 27 owing to the springs 28 until one of the steps in each of the templates is arrested by the set slide bars 3, 7. The movement of the templates is communicated to the differential gear 9, 10, 11 imparting to the ring 11 a movement proportional to the units part U of the product. At the end of the forward stroke of the handle a device (not shown) is operative to shift the gear wheels 31 from engagement with the toothed disc 14 into engagement with the ring 11. On the return stroke the shaft 24 is returned to normal position, thereby the arms 27 compel the templates to return and the ring 11, through the transmission pinions 31, 32, 33, imparts its setting to the totalizer drums 34. Finally, when the wheel 38 disengages from the pinion 39, the wheel 37 returns the shaft 23 to normal position and the discs 2, 6 return to the position they occupied before the operation. The totalizer carriage is displaceable laterally towards the left and the next lower digit of the multiplier set by the lever 35. A suitable transfer mechanism (not described) for the totalizer, capable of transferring as many as four times during a single operation, is provided. Addition is effected by utilizing '' 1 " as a multiplier, while subtraction and division are performed similarly to addition and multiplication by a reversal of the timing of movement of the gear wheels 31 in respect of their co-operation with the ring 11 and toothed ring 14. The slide bars 3, 7 may be controlled by cams having a translatory movement or by means of a linkwork, the movements being effected by the manipulation of the keys of a keyboard. The rotary templates may be replaced by stepped plates having a rectilinear motion, as shown in Figs. 29 and 31 ; the extent of the movement is limited by the setting of the slide bars 3, 7 and is communicated through a rack 64 on the plate 45 and a pinion 48 on the plate 46 to a rack 47 operatively connected to the totalizer. In another modification, Figs. 32, 33 and 35, a single template 50 is employed for each denomination and the differential gear 9, 10, 11 is replaced by a single gear wheel 59. The template 50 is loose on the shaft 24 and is provided with a pin 51 maintained in engagement with an arm 52 secured to the shaft by means of a spring 60. The steps of the template can engage either the slide bar 3 or a pin 53 projecting from a member 56 slidably mounted on the wheel 59 and engaging a notch in the slide bar 7. The notch compels the member 56 to follow the displacement of the bar 7 but permits it and the pin 53 to move with the wheel 59 when the latter rotates counterclockwise. As the template rotates in the same direction as the wheel 59 the direction of rotation of the shaft 24 is contrary to that considered above. During the forward stroke of the handle the template is rotated and first a step strikes the pin 53 thus causing the wheel 59, which is loose on the shaft 24, to partake of the movement, which movement is arrested when the slide bar 3 strikes another step. On the return stroke of the handle the displacement of the wheel 59 is transmitted as above described to the totalizer.