Patent GB-787893-A (GB)
Abstract: 787,893. Calculating-apparatus. OLIVETTI & C. SOC. PER AZIONI, ING., C. Sept. 26, 1956 [Oct. 6, 1955], No. 29349/56. Class 106 (1). In a machine adapted for short cut multiplication, comprising a multiplier store which is not reset and whose denominational elements are sensed sequentially for setting a cycle counting device, each storage element is formed with digit steps and those for the short cut digits are reversed, relatively to those for other digits, whereby complementary values of the former digits are sensed. The invention is applied to a ten-key machine having a pin carriage 20 for setting differential actuator racks 21 associated with an addsubtract totalizer 22. The multiplier storage device or register comprises a set of slides 32 carried by transverse rods 34 and 34<SP>1</SP> secured to a side plate 35 on a shaft 36. This shaft is rocked to engage ears 37 on the slides with rack teeth 38 on the actuator racks, for the purpose of setting the multiplier. Latches 40, in a frame 41 pivoted at 42 to the side plate 35, normally engage the slides 32 to retain them in set position but are rocked clear, by engagement of a stationary stud 44 with a cam slot 43 in the frame 41, when the plate 35 is rocked to engage the slides with the actuated racks. Setting multiplier. Depression of a multiplier key 45, Fig. 2, initiates cyclic operation in which a control slide 48 is released to its spring 49 and arrested in position IV by the stop stud 46 of the key. An ear 55 on the slide 48 rocks a lever 56 counterclockwise which lowers a link 61 for a hook 62 thereon to engage a stud 63 on a lever 64. However, before the hook can engage the stud, a first lobe 72 of a main cam 71 rocks a lever 68 which shifts the link 61 forwardly so that the hook passes clear of the stud. Meanwhile, during this first half-cycle, the differential racks 21 are adjusted to the multiplier value set on the pin carriage 20. During the second half-cycle, the second lobe 73 of the cam 71 again shifts the link 61 forwardly and with its hook 62 now engaged with the stud 63. The lever 64 is consequentially rocked counterclockwise and a cam slot 66 therein rocks the plate 35 clockwise to engage the ears 37 with the differential racks 21, so that the slides 32 are adjusted to the multiplier value as the racks 21 are restored. The slides 32 are reset by abail 76, Fig. 2, adapted to be actuated by the follower (not shown) of a main cam. The follower normally lies clear of the cam and is inactive. Depression of the multiplier key 45 cams a second slide 88, Fig. 2, rearwardly and a slotted lug 87 on the slide cams a shaft 81 inwardly which shifts the follower into alignment with the cam, so that the bail 76 is actuated to reset the slides 32. The multiplier is, therefore, retained by the slides until a new value is entered by actuation of the multiplier key 45. Initiating multiplication and preventing operation with excessive values. Depression of the multiplication key 94, Fig. 6, releases a lever 97 to a spring 120, the lever actuating an arm 100 to operate the motor-bar of the machine. The lever also shifts a link 102 forwardly so that a lug 105 thereon rocks an arm 106 out of normal driving engagement with a stud 108 whereby cyclic return of the pin-carriage registering the multiplicand is prevented. The link 102 also rocks a lever 103 clockwise to move a bail 110 forwardly, see also Fig. 7, below the multiplier slides 32. The bail 110 is slidable laterally of the machine (upwardly, Fig. 7) on rods 109 and 112 under spring action and control of a lever 116 connected with the pin carriage 20. If the sum of the multiplier digits, set on slides 32, and the multiplicand digits, set on the pin carriage 20, exceeds the capacity of the multiplier registering slides 32 (one digit less than the totalizer 22), the beam 119 of the bail 110 abuts the rear edges of one or more of the higher order set slides 32 during its forward movement, forward movement of the link 102 is arrested and the lever 96 does not actuate the arm 100 to initiate operation. Operation is not, however, prevented if the excess is one digit and the highest digit of the multiplier is less than five. To this end, the beam 119 is reduced in height at its end 119<SP>1</SP> so as only to be arrested by a slide 32 set to a digit value of five or over. If no multiplicand has been set, the carriage 20 and bail 110 remain in their normal positions of Fig. 7, the bail is arrested by engagement with a fixed stud 121 and the arm 100 again is not operated to initiate operation. Multiplication. The multiplier register slides 32 are formed with digit steps 155 and 156, Fig. 1, adapted to be sensed by a finger 157 of a cycle counting slide 159 carried in front and rear plates 123 and 124 of a sensing carriage 122. The sensing carriage is mounted on transverse rods 127, 128 and is denominationally shiftable, to sense the slides 32 in succession, with the pin carriage 20. The counting slide is formed with ratchet teeth 160 engaged by a pawl 161 which restrains the slide against forward movement under spring action from its normal rearward position shown. During the first of each series of multiplicative add cycles, a bail 164 is lowered and trips the pawl 161, so releasing the counting slide for forward adjustment to the multiplier digit determined by engagement of its sensing finger 167 in one of the digit steps of the slide 32. During each subsequent-cycle of the series, the bail 164 is reciprocated rearwardly and then forwardly and returns the counting slide step-wise by engagement with the ratchet teeth 160. When, after a number of cycles corresponding to the sensed multiplier digit, the slide resumes its initial position, the bail 164 drops into a clearance notch 191 and into engagement with the end 195 of an adjacent slide 189. The slide 189 is consequently moved rearwardly and operates the step-shift mechanism of the pin carriage 20 in preparation for the next series of add cycles. For step-shifting the sensing carriage 122 with the pin carriage 20, a comb plate 130 is slidable on transverse rods 131 and 132, see also Fig. 7, above the sensing carriage and is rigidly connected by an arm 129 with the pin carriage. A slide 135 is carried in the front and rear plates of the sensing carriage and is cyclically advanced to engage a lug 146 in a notch of the comb. This movement of the slide is effected by a bail rod 137 carried by a lever 152, Fig. 6, pivoted at 148 and adapted to be oscillated by a main cam 153. The cam only actuates the lever after depression of the multiplication key 94, the resulting movement of lever 103 raising a link 151 which cams the lever 152 into engagement with the cam. Short cut multiplication. According to the invention, the steps 156 in each multiplier slide 32, Fig. 1, for the digits five to nine, are reversed relatively to the steps 155 for the digits one to four, so that complementary values are sensed by the counting slide 159. Each multiplier slide 32, has a projection 197 adapted to be sensed by lugs 198 and 200 of a sensing slide 199 mounted in the sensing carriage 122. The lower lug 200 is set further back than the lug 198, and the slide is adapted to be advanced cyclically by means of a rod 202. In the case of multiplier digits one to four, the upper lug 198 abuts the projection 197 and the totalizer remains in its normal add position. With the multiplier digits five to nine, the lower lug 200 abuts the projection, and the consequent further forward movement of the slide 199 and rod 202 results in the totalizer being positioned for subtraction. If the multiplier digit is zero, the projection 197 clears the lug 198, the slide executes a full forward movement which conditions the machine for a non-add operation. With digits five to nine, the subtract cycles are followed by an additional cycle in the next higher order. To this end, the sensing carriage has a further slide 221 with a lug 226 disposed half a denominational step to the right of the lug 200 and extending forwardly beyond that lug. During multiplication, the slide moves forwardly to the broken-line position of the lug 226 and then abuts the sides of the projections 197 of slides 32, set to multiplier digits five to nine, during denominational shift of the sensing carriage. The effect of this is to restrict movement of the sensing carriage to half a step, whereby a leftward offset sensing finger 158 of the counting slide 159 becomes effective to sense the next higher multiplier slide 32 in place of the normal finger 157. This finger 158 is positioned one digit step higher than the finger 157 so that the number of cycles effected will correspond to the multiplier digit registered increased by one. When the bail 164 enters the notch 191 of the counting slide 159 during the last of such a series of cycles, it also engages a step 224 in a downward extension of the slide 221, displacing the slide and lug 226 to clear the engaged projection 197 so that the sensing carriage is able to complete the previous step movement as it makes the next. Concluding cycle. When multiplication is complete, the sensing carriage 122, Fig. 1, reaches a position where a sensing lug 143 on the slide 135 is able to enter recesses 144 in the unset higher order slides 32. The slide 135 and bail rod 137, Fig. 6, are now allowed an increased movement permitting the lever 152 to follow the cam 153 fully. This positions the link 151 beneath a lug 245 of a cyclically rocked lever 246, resulting in a lowering of the link 151 which rocks the lever 97 counterclockwise so that a retaining arm 96 therein releases the depressed multiplication key 94 to stop the machine. An additional add cycle in the next higher order is, however, necessary when the concluding cycles are subtract ones. Under these conditions, the movement of the sensing slide 199 and rod 202 positions a lug 249, Fig. 6, on an arm 203 carrying the rod