483,093. Calculating - machines. NATIONAL CASH REGISTER CO. Oct. 14, 1936, No. 27926. Convention date, Oct. 14, 1935. [Class 106 (i)] A calculating-machine of the Ellis type, having means for transposing the complement of an overdraft into a true negative amount, is now provided with a rotary main shaft adapted to be coupled to a constantly rotating drive shaft for one revolution upon depression of the motor bar and for three revolutions upon depression of the overdraft key. The invention is described as applied to the machine forming the subject matter of Specification 28253/08, [Class 106], modified to print true negative totals as described in Specification 420,807. The usual oscillating main shaft and flying lever are now dispensed with and the various mechanisms of the machine are driven by cams on a rotary main shaft, the machine release and totalizer-engaging mechanisms being modified for this purpose. Driving means. The main shaft 53, Fig. 3, is geared to an internal clutch member 47 free on a constantly rotating shaft 48. A clutch band 54 is secured at one end to the periphery of the member and at the other to a lever 55 pivoted to the member and pin-and-slot connected to a control arm 57. Upon the release of the arm by a lever 59, the arm rocks counterclockwise to expand the band and render the clutch effective. At the end of a revolution, the control arm is intercepted by the lever 59 which has been restored by a stud 79 on one of the intermediate gears, the clutch is opened and the main shaft arrested. Releasing machine for normal operations. The clutch release lever 59, Fig. 3, is linked to a latch 62. Upon the depression of the motor bar 73, a stud 65 on the usual three-armed lever 66 frees the latch, which with the release lever is rocked counterclockwise by a spring to enable the clutch to become operative for one revolution. If the motor bar is held depressed, a second operation is prevented by a non-repeat pawl 87. The motor bar is normally locked, but is released when the paper carriage is in certain positions or an operation-control key is depressed. The totalizers. The machine is provided with the usual balance totalizer and three adding totalizers adapted to be engaged with the actuators upon the rocking of cam plates embracing the totalizer shafts. Adding. The engaging cam plates of each adding totalizer are operatively connected to a link 189, Fig. 21, slotted to co-operate with a pin 213 on an adding engaging-plate 214 rocked in accordance with " add " timing by cams 218 on the main shaft 53. The links are normally raised out of the path of the pin 213 by a comb 193 controlled by a cam on the main shaft and are latched in this ineffective position by ears 187, that take under shoulders on the links and are controlled by stops on the paper carriage. Positioning the paper carriage releases one or more of the links and upon the operation of the machine the comb lowers these links to couple them to the engaging plate. At the end of the operation, the comb returns the links into position to be relatched by ears 187. Unselected links are held in their left-hand ineffective positions by a resiliently mounted bar 224. In non-add operations, all the links are held in raised position by a bail 281. The engaging link 322, Figs. 32 and 34, for the balance totalizer is similarly controlled in adding operations. The above totalizer-engaging mechanism is similar to that described in Specification 481,730. Subtracting. To engage the balance totalizer for subtraction, the engaging link 322, is rocked upwardly from the position shown in Fig. 32 to that shown in Fig. 34, whereby a notch in its upper edge is caused to engage a stud 346 of a subtracting engaging-plate 338 rocked in accordance with " subtract " timing by cams 344 on the main shaft. At the same time, a subtract link 305 connected to the usual transfer conditioning shaft is rocked downwardly to engage its ear 336 with a shoulder on the subtracting engaging-plate. For this purpose, the links 305, 322 are connected by a beam 319 pivoted to the subtract link and slotted to engage a pin 321 on the engaging link. Upon the depression of the subtract key 259, a lever 301 is rocked clockwise to interpose the hooked lower end of an arm 316 beneath a stud 318 on the connecting beam 319. Simultaneously, an ear 303 of the lever 301 is removed from beneath a shoulder of the subtract link to enable the latter to rock downwardly. This movement causes the connecting beam to rock about the stud 318 and elevate the engaging arm. The balance totalizer is now engaged during the first part of the operation by the right-hand movement of the link 322 and restored prior to the restoration of the actuators. The subtract link 305 partakes of the right-hand movement and is then held by the engagement of a lever 347 with a shoulder on the underside of the link. After transfer has been completed, the lever 347, which is resiliently connected to the comb 193, releases the subtract link for return to home position. Printing totals. A total is taken by engagement of a selected totalizer in accordance with subtract timing and arresting the actuators under control of the transfer mechanism in usual manner. Upon the depression of one of the usual total-taking keys 259, Fig. 29, a detent bar 373 slides to the right and rocks a total lever 374. The cam-shaped end 375 of this lever is thus caused to abut a stud 376 on the totalizer engaging link 189, Figs. 21 and 29, thereby the latter is raised and coupled to the stud 346 of the subtracting engaging-plate. During the ensuing operation, the link is guided by the upper surface of the flexibly mounted bar 224. The depression of a total key releases the repeat key or any amount keys that may be depressed at this time, the locking movement of the detent 373 being communicated to a rod 389 for this purpose. Printing subtotals. A subtotal is taken by depressing the subtotal key, Fig. 29, in conjunction with one of the total keys, with the result that the selected totalizer is engaged by the subtracting engaging-plate and disengaged by the adding engaging-plate. For this purpose, depression of the subtotal key causes the resiliently mounted bar 224 to become coupled to a link 380 pivoted to the adding engaging- plate 214. This plate makes its engaging movement prior to the disengaging movement of the subtracting engaging-plate with the result that, after the total has been taken from the totalizer, the bar 224 is shifted to the right and the engaging link 189, thus released, falls to its lowermost position in which it is coupled to the adding engaging-plate. The total is now reentered into the totalizer prior to disengagement. Overdraft converting and printing operation. When the balance totalizer is in overdrawn condition, the total key for the balance totalizer becomes locked and an overdraft key 408, Fig. 3, is freed. Depression of the overdraft key releases the machine for three cycles during which the complementary total standing on the totalizer is converted into a true negative total and printed. The method of effecting this conversion is similar to that described in Specification 420,807. In the first cycle, the complementary total is cleared from the balance totalizer and retained in an auxiliary register. In the second cycle the cleared balance totalizer is engaged subtractively and the complement standing on the register is entered thereinto. In the third cycle, the true negative total, now standing on the balance totalizer as a positive total, is cleared and printed by an ordinary total-taking operation. These operations are controlled by a cam 486, Fig. 10, fast on a shaft 67 that makes a single revolution during the three cycles of an overdraft operation. The cam determines the angular position of an arm 494, Figs. 10 and 21, that is connected by a link 496 to the total lever 374 for the balance totalizer, by a link 497 to the subtract lever 301, by a link 498 to means governing the selection of one of the adding totalizers wherein the complements of the negative totals are stored, and by a link 501 to the amount-key release means. Releasing machine for overdraft operation. The overdraft key 408, Figs. 3, 5, and 8, is formed in two parts comprising a stem 409 coupled by a latch 414 to a pitman 410. Depression of the key is normally prevented by a detent 420, Fig. 8, connected to the usual overdraft shaft 424, rocking of which, upon the overdrawing of the balance totalizer, disables the detent 420 and locks the balance totalizer total key by a latch 428, Fig. 21. Upon depression of the overdraft key, a slotted link 419, Fig. 3, rocks the three-armed lever 66 to release the machine, and a finger 450 of the link disables the non-repeat pawl 87. At the same time, cam-shaped projections 442, 445, Fig. 5, on the pitman rock a pawl 435 counterclockwise to couple the shaft 67 to a wheel 432 that makes one revolution for three of the main shaft. The pitman is latched down by a pawl 447, Fig. 8, that is disabled after three cycles by a cam 452 on shaft 67. In the event of the key being held down, a stud on the pawl 447 disables the latch 414 to enable the pitman to be spring- restored independently of the key stem. At the end of the operation, the overdraft shaft is restored to normal position by a latch 456 that causes the detent 420 to participate in the final clockwise movement of the pawl 447. Disabling printing-mechanism. The usual printer shaft 116, Fig. 11, is driven by cams 106 on the main shaft 53 through a lever 110 pin-and-slot connected to a link 112. As printing must be suppressed during the first two cycles of an overdraft operation, cams 470 are provided on the shaft 67 to swing the link 112 out of engagement with the lever 110 and into engagement with a fixed stud 472 during this period.