Patent GB-635580-A (GB)
Abstract: 635,580. Calculating-apparatus. NATIONAL CASH REGISTER CO. May 21, 1947, No. 13675. Convention date, Nov. 2, 1946. [Class 106 (i)] The differential mechanism of a calculating machine comprises in each denomination two members connected to move complementarily and so arranged that one member engages an operated digit key after moving an amount corresponding to the complement of the said digit and the other is in consequence set to the true value of the digit, the latter member driving a transmitting means connected to printing mechanism, the printing mechanism being left in set position at the end of an operation and restored at the beginning of the next operation. General operation. In the machine described, the two members are, respectively, an upper rack 103, Fig. 2, which moves to represent the complement of a set digit, and a lower rack 109 which moves to represent the actual digit. A balance totalizer 611 is driven by the upper rack 103 and transaction totalizers arranged on three lines 132, 134, 136, each carrying nine totalizers, are driven by the lower rack 109. The balance totalizer comprises in each denomination a pair of (" plus " and " minus ") wheels intergeared to rotate in opposite directions. When the minus wheel stands at " 0 " the plus wheel stands at " 9 ". In adding, the plus wheels are engaged with the upper actuating racks 103 and transfer mechanism and the complement of the item is added to said wheels and simultaneously subtracted from the minus wheels. In subtracting, the minus wheels are engaged with the upper actuating racks and transfer mechanism and the complement of the item is added to said wheels and simultaneously subtracted from the plus wheels. When the highest wheel of the side of the totalizer selected for engagement passes through zero in the adding direction, one unit is added to the lowest wheel on that side. As long as the balance is positive the minus side holds the true amount but the positive side is selected for total and subtotal taking, since this side sets the upper racks 103 to the complement of the true amount and the lower racks 109 thus transmit the true amount to the printing wheels. When the balance is negative, the minus wheels, which then hold the complement of the balance are engaged with the upper racks, the lower racks setting the printing mechanism to the true amount. The plus wheels drive indicator wheels carrying two sets of numbers, " 0 " of one set being adjacent " 9" of the other, and so on. One set thus displays the amount on the positive side and the other on that on the negative side. Known shutter mechanism covers the set of numbers which is not to be read. The sign of the total can thus be ascertained by inspection. Differential-actuating mechanism for totalizers and for printing wheels. A driving shaft 116, Fig. 2, journalled in the machine frame is rotated clockwise by cams 126 on the main shaft 71 acting through links, levers and a rack, not seen in Fig. 2. A shaft 112 is carried in links 113 pivoted to cranks 114 fixed to the driving shaft 116. In each denomination, a floating pinion 106 on the shaft 112 gears with a primary differential slide 103 and a secondary slide 109, the latter driving the line (transaction) totalizers 132, 134, 136. Resistance to the movement of the secondary slide is greater than that to the movement of the primary slide. The floating pinion 106 thus rolls over the secondary slide 109, driving the primary slide 103 to the right until the latter is arrested by a depressed numeral key, the slide 103 then having moved a distance corresponding to the complement of the depressed-key value. Continued movement of the floating pinion 106 then drives the secondary slide 109 a distance corresponding to the value of the depressed key. Initial movement to the right of the secondary slide 109, Fig. 19, causes a cam 138 thereon to rock clockwise a lever 140 pivoted at 141 and carrying a pin 143 in a cam slot in a latch 145 so that the latch is engaged with retaining teeth 148 in the primary slide 103 to lock this in set position during movement of the secondary slide 109. The latch 145 is carried on a rod 146 carried in a frame 149 which as described below is rocked counterclockwise in total taking to render the latch 145 ineffective. In order to transmit the amount set to the printing wheels 177, Fig. 2, each primary slide 103 engages a primary pinion 155 having a lug 159, Figs. 4, 5, while each secondary slide 109 engages a secondary pinion 157 having a lug 163. An intermediate pinion 161 has lugs 160, 162 co-operating with the former lugs 159, 163. If the setting be, e.g. 7, the complementary movement (to the right, Fig. 4) of the primary slide 103 turns the primary pinion 155 and lug 159 clockwise two steps. The secondary slide 109 then turns the secondary pinion 157 and lug 163 seven steps counterclockwise, the secondary lug 163 pushing the intermediate lug 162 and thus the intermediate pinion 161 seven steps counterclockwise until the other lug 160 on the intermediate pinion 161 abuts the previouslymoved primary-pinion lug 159. The intermediate pinion 161 gears with a segment 165, Fig. 7, normally connected by a latch 168 to a printer sector 170 driving a ring gear 171, the ring gears for each denomination being connected in a manner similar to that disclosed in Specification 280,828, [Class 100 (iv)], by a pinion 174, shaft 175, another pinion and another ring gear 176 to a corresponding printing wheel 177. An aligning bar 204 operated by cams on the main shaft co-operates with the printer sector 170. The means moving the bar can be disabled, the bar then remaining engaged with the sector 170, by appropriately setting a finger lever 225. Return of the primary and secondary slides 103, 109 leaves the intermediate pinion 161, the segment 165 and printing sector in set position from which they are restored early in the next operation. Restoration is effected by cams on the main shaft 71, Fig. 16, which lowers a link 241 to rock clockwise a restoring lever 239 having teeth 238 which drive counterclockwise a shaft 166, Fig. 7, having fixed to it a crank 234 which picks up and restores the segment 165 and connected parts. The action of this restoring mechanism is inhibited by the finger lever which disables the aligning-bar moving means. The segments 165 are turned clockwise to position 9 prior to total and subtotal taking as described below. Controlling printing of zeros. After the printing wheels have been set, arms 257, Fig. 7, are rocked counterclockwise and carry with them a rod 256 on which are pivoted zeroeliminating pawls 255. Tails on the pawls 255 are thus moved away from a fixed rod 267. A spring 268 then tends to rock the pawls clockwise but this is prevented in any denomination in which a digit is set because a surface 271 of the printer sector 170 will then have moved clockwise to block the pawl. If no digit is set, the pawl 255 rocks clockwise, Fig. 25, to disengage a latch 168 which normally connects the printer sector 170 to its segment 165. Continued movement of the pawl 255 then turns the printer sector 170 one step by the engagement of the nose 254 of the pawl with a shoulder 270 of the sector, this step turning the printing wheels back from zero to a blank space. All zeros to the left of the highest figure are thus eliminated. To prevent elimination to the right, each pawl 255 has a pin 272 which, if the pawl cannot rock because a digit is set in that denomination, prevents the rocking of the next lower pawl, and this in turn holds the next lower pawl, and so on. The three lowest denominations are not provided with zero eliminating mechanism. The printing wheels remain in the blank positions until the arms 257 are restored early in the next operation, the tails 266 of the pawls 255 being forced against the fixed rod 267 so that the pawls are rocked counterclockwise, projections 269 thereon engaging the latches 168 to push the printer sectors 170 on to zero and then to relatch them to the segments 165. Addition in transaction totalizers. Each of the three transaction totalizer lines is controlled by a corresponding bank of selecting keys 77, Fig. 1, for selecting as described below the desired one of the nine totalizers on the line, and by control keys for causing the taking a subtotal (" read " key 74), a total (" reset " key 75) or subtraction (key 76) in the selected totalizer. If a selecting key 77-is depressed, but no control key, the corresponding totalizer is selected for addition. If no selected key 77 is depressed, the corresponding totalizer line is not engaged, regardless of whether a control key 74-76 is depressed. Depression of any selecting key 77 moves to the right a bar 283, Fig. 10, which by a link 289, swings counterclockwise a non-add stop lever 290 away from a control finger 294 pivoted on a shaft 380 and later urged counterclockwise by a spring 383, Fig. 11, connected to a crank-lever 304 rocked clockwise by cams on the main shaft. A stop lever 301 is positioned by the control keys 74-76. If no control key is depressed, an " add " stop 379 is in the path of finger 294 to position it for addition. An arm integral with the finger has a slot 384 in which slides a pin 385 on a link 386 pivoted to the cranklever 304. By engaging with cam slopes 387 in a control lever 388, the pin 385 sets the control lever 388 in accordance with the (add)' setting of the finger 294, this setting being communicated by a link 389 to a lever 390, Fig. 10, an arm 392 of which sets a plate 394 having a slot 398 in which runs a totalizerengaging pin 399 on a link 400 pivoted to a crank 401 on the engaging shaft 402 carrying the cams 403, Fig. 28, which shift the totalizer frame 363 into engagement with the differential slides 109. The pin 399 is thus placed between horns 420, 421, Fig. 10, on a slide reciprocated by control-shaft cams in such a timing as to rock the