693,659. Calcutating-apparatus; transfer mechanism; zeroizing-mechanism. NATIONAL CASH REGISTER CO. April 20, 1951 [June 29,1950], No.9243/51. Class 106 (i). In a calculating-machine, the totalizer has, in each order, a single main pinion engageable directly with its actuator for addition and an auxiliary double pinion having one set of teeth engaging the main pinion and another set in a different plane which is aligned with the actuator for subtraction by a transverse shift of the totalizer frame, a pair of transfer teeth being mounted integrally with the main pinion in offset relation for co-operation in addition and subtraction respectively with two mutually offset portions of a common transfer lever. The invention is applied to a full keyboard motordriven machine of the Allen-Wales type, as described, for example, in Specifications 698,524, 606,627 and 608,989. Each differential actuator lever 76, Fig. 2, carries a rack 123 engaged during the middle part of each cycle by an aligning bar 124 operated by cam-controlled scissor arms 136, 137. To prevent rebound of the stop-bars 74, Fig. 10, each carries a rack 144 engaged during its forward movement by a pawl 145. Addition and subtraction. Secured to each totalizer wheel is a main pinion 275, Fig. 12, constantly meshing with one set of teeth 279 of a double pinion. In addition, the main pinions are aligned with the actuator racks 276 which pass between the sets of teeth 277, 279 of the double pinions. For subtraction, the totalizer frame is shifted laterally to align the teeth 277 of the double pinions with the actuators. Depression of the subtraction key moves a link 299, Figs. 5 and 23, forwardly to rock a link 301 so as to position a surface 308 thereon in the path of a stud 307 in a plate 306 on a shaft which is oscillated during each cycle. Consequently, in the following cycle, the link 301 is depressed and rocks a lever 303 formed with a cam slot 304 engaged by a roller 305 secured to a shaft 250 on which is mounted the totalizer frame which is thus moved to its subtraction position. The link 301 remains in the depressed subtraction position until the next add operation when, since the slide 299 remains in its rearward position, a surface 317 on the link 301 is engaged by a stud 316a in the plate 306 and the link is moved upwardly to restore the totalizer frame to the add position. The subtraction key is held depressed during a subtraction operation by a latching slide released by cam means. For addition and subtraction, the totalizer is disengaged during the first half-cycle and then engaged. An arm 403, Fig. 27, is rocked counter-clockwise and then restored in each cycle and pivoted thereto is an arm 404 urged into alignment with the arm 403 by a spring 406 and formed with a hook which normally engages a stud 408 in a lever 409. Immediately the arm 403 starts to rock, the lever 409 is rocked counter-clockwise. A link 418, urged upwardly by a spring 424 but normally held in a lower position by the engagement of a lever 427 over a stud 420, is thus moved to the left to rock a lever 430, a stud 429 in which is engaged by a hook of the link 418, clockwise. A stud 433a in the lever 430 rocks a lever 289 which by means of a cam slot rocks a lever 286 fast on the shaft 250 of the totalizer to disengage the latter. In the middle of the cycle, after the arm 404 has disengaged the stud 408, it is engaged by a further stud 412 in the lever 409 which rocks it clockwise until its tail 413 engages a stud 414 in the arm 403 when the final counter-clockwise movement of the arm 403 restores the lever 409 clockwise. The lever 430 is thus returned counter-clockwise and a pawl 431 carried thereby engages a stud 433 in the cam lever 289 to return it and thus to engage the totalizer. A stud 415 in a sprung detent lever locates the lever 409 in the position to which it is moved. When the totalizer is disengaged, extensions 240, Fig. 12, of a plate 241 adjustable on a spring-loaded bail 242, engage the totalizer pinions to prevent accidental rotation. An extension 244 of the bail engages the fixed machine frame when the totalizer is engaged to hold the projections 240 from the pinions. Transfer mechanism. Each totalizer wheel has two offset transfer teeth 267, 268, Figs. 13 and 21, which co-operate respectively with offset portions 328, 322 of a transfer lever 320, Fig. 2, in subtraction and addition, the totalizer being shifted axially as described above for subtraction. When a transfer lever is rocked by a transfer tooth, it is held by a latch 352. An ear on the lever is thus moved from the path of a lug on the actuator rack 276 of next higher order so that the latter, which is slidable on its lever 76, may be driven through an additional step by a spring. Any operated transfer levers are restored early in the next machine operation when, as the totalizer is disengaged, ears on the totalizer frame engage forward tails 356 of the transfer latches 352. Fugitive-one mechanism. When a " trans. fer " lever 360, Fig. 19, associated with the highest order is operated, it is held by a latch 361 which by means of a link and arms on a cross-shaft rocks a bail adjacent to the units order, an abutment on this bail being thus moved from the path of a lug on the units order actuator rack so as to permit the latter to move an extra step to enter the fugitive one additively or subtractively according as to whether the totalizer is going positive or negative. To prevent entry of the fugitive one when the capacity of the totalizer is exceeded, an ear 384 on a tail of the latch 361 co-operates with an E-shaped arm 381, see also Fig. 23, which is pivoted on the same stud 303a as the cam lever 303 which is rocked clockwise to shift the totalizer to the subtraction position. A spring between studs 384a and 382 in the cam lever 303 and arm 381 urges the arm 381 upwardly when the machine is adding and downwardly during subtraction. When the totalizer is positive and subtraction is being performed, the centre projection of the arm 381 engages the ear 384 of the latch 361 so that the arm 381 cannot complete its downward rocking. When the totalizer goes negative, however, the latch 361 is able to rock counter-clockwise to enter the fugitive one and the arm 381 is able to rock clockwise, the ear 384 entering the upper portion of the " E." If further subtractions cause the capacity to be exceeded, the lever 360 will be rocked but only a small counter-clock. wise movement of the latch 361 is permitted, the ear 384 engaging the downwardly projecting end of the upper projection of the arm 381. This small movement is insufficient to cause the entry of the fugitive one. Similarly, the latch 361 is able to complete its movement during addition when the totalizer goes positive but not if the totalizer is already positive. Total-taking. During a two-cycle totaltaking operation, if the total is positive, the main totalizer pinions are engaged with the actuators and are reversely rotated until each positive transfer tooth engages the corresponding abutment on the transfer lever or, if the total is negative, the negative transfer teeth are driven against the corresponding abutments on the transfer levers, the totalizer being moved automatically to the subtraction position. When the total key 27, Fig. 30, is depressed, a finger 504 thereon engages a stud in a slide 506 which is consequently also depressed. A tooth 511 on the slide 506 co-operates with a stud in a lever (not shown) held by cam means against movement until the end of a cycle so that the slide is held depressed and also preventing depression of the total key during a cycle. Depression of the slide 506 rocks an arm 531 carrying a stud 542 normally held in an upper notch in a link 543 urged downwardly by a spring 549 and pivoted to a plate 540 which is thus rocked to draw a link 546 to the right. A stud 567 in the plate 540 rocks a lever 492 associated with the driving mechanism to start a machine cycle. During this first cycle, a stud 560, Fig. 9, in the link 546 rocks a stop bail 564 to prevent movement of the stop bars 74. As the link 546 moves rearwardly, an arm 570, see also Fig. 23, pin-and-slot connected thereto, is rocked and in its turn rocks a bail 574 carrying a lever 579 urged counter-clockwise by a spring 580. If the total is positive, the fugitive-one control member 381 described above is in its counter-clockwise position and an extension 583 thereof will hold the lever 579 depressed to an ineffective position. However, if the total is negative, the member 381 is in a clockwise position and the lever 579 in an upper position so that a hook 584 thereof will engage a stud 585 in the subtraction control slide 299 described above which will be moved forwardly to cause the totalizer, if in the add position to be moved to the subtract position. The rocking of the arm 570, Fig. 27, also frees a latch 602 on a cam-operated link 605 so that when the link is moved to the left, the latch engages a notch 609 in a control link 603 which is consequently moved to the right when the link 605 is restored at the end of the first cycle. At this time, a pawl 550, Fig. 30, in a plate on the main shaft raises a stud 551 in the link 543. As this moves the stud 542 from the upper notch in the link 643, the latter and the connected parts are partially restored so that the stop bail 564, Fig. 9, is moved from the path of the stop-bars. The restoration of the link 543 is, however, limited by the arm 570 which is held by the latch 602 against which the control link 603 is pressing. At the end of the first cycle, a latch 477 is held in a counter-clockwise position by the link 603. The tait of a lever 480 associated with the driving mechanism is thus able, when freed by a cam, to pass over a tongue on the latch 477 so as to initiate a further cycle. As the latch 602 is moved to the left in this further cycle while the link 603 is held by the latch 477