471,765. Cash registers. SOC. ANON. OFFICINE DI VILLAR PEROSA. March 28, 1936, Nos. 9297 and 9298. Convention dates, March 29, 1935 and March 3, 1936. [Class 106 (i)] In a cash register having differential mechanism of the kind wherein a driving member associated with each amount bank receives a constant to-and-fro excursion at each operation to move an actuator through an angle proportional to the value of the depressed key, the actuators are zeroized during the first period of each operation and, during the second period, are given an operative rotation under the control of the amount keys in adding operations and of the totalizer wheels in total and subtotal taking operations. Keyboard. The machine is provided with banks of amount keys 5, Fig. 1, a bank of characterizing keys 4, Fig. 23, each controlling a totalizer, and an operation control lever 6, Fig. 29, geared to a cam plate on the differential shaft 20, Fig. 1. The lever and plate have five positions for adding and the taking of totals and subtotals from the grand and subsidiary totalizers. The lever is normally locked but is released upon the insertion of a key in a slot 163, Fig. 29. Differential mechanism. Associated with each amount bank, Fig. 1, is an actuator 21 and a driving arm 23 to which is pivoted a lever 25 terminating in a hook 26 and carrying a one-way pawl 27. Cams on the main shaft 3 rock the shaft 20 and arms 23 first clockwise and then counterclockwise at each machine operation. During the clockwise excursion, arms 36 on the shaft 20 reset the actuators by abutment with spokes 37, the movement of the drivers 23 being rendered ineffective during this period by the pawls 27 wiping idly past the stems of the depressed keys. On the return movement of the drivers, the pawls 27 abut the depressed keys and force the levers clockwise to engage the hooks 26 with teeth 22 on the actuators, the hooks being maintained in engagement by studs 29 taking over shoulders 32 on latches 24 connected to the hooked levers by springs 33. At the end of the operation the actuators will have been rotated counterclockwise through angles proportional to the values of the depressed keys. They are locked in this condition by aligners 61 and are freed from the hooks 26 by rock-arms 35 disabling the latches 24. Totalizers. The machine is provided with a grand totalizer C, Fig. 1, that receives all the items, and with three subsidiary totalizers (one only shown in Fig. 1) spaced around the peripheries of the actuators 21. Each totalizer comprises denominational wheels 44 mounted on a shaft 46 carried by a frame 41, Fig. 16, that is rockable about a shaft 43 to engage the wheels with the actuators. Shafts 47 mounted in the frames carry transfer mechanism of known kind. Engaging-mechanism for the subsidiary totalizers. The means for rocking the frames 41, Fig. 16, to engage the totalizer wheels 44 of the subsidiary totalizers with the actuators 21 comprise a segment 113, Fig. 17, shifted clockwise and counterclockwise twice during each operation by a cam 114 on the main shaft 3. Associated with each totalizer is a three-armed lever 118 pivoted to the segment 113. One arm of each lever 118 is hooked to co-operate with a lug 111 on the associated totalizer frame and, in the absence of preventing means, would engage the totalizer at tho end of each of the first and second periods of an operation. Disposed in the path of an arm 119 of the three-armed lever 118 is a stop 120a on a lever 120 controlled by the associated item-characterizing key 4. This stop normally disables the hook 124 and prevents the engagement of the totalizer. However, upon the depression of the appropriate key 4, the stop 120a is shifted out of the path of the arm 119 and engagement of the totalizer occurs at the end of the first period. In adding and total-taking operations, the characterizing key 4 is released prior to the end of the operation and no second totalizerengagement occurs, but in subtotal taking operations the key is not released until the end of the operation and the totalizer is reengaged as described below. Engaging-mechanism for the grand totalizer. The means for engaging the grand totalizer is similar to that for engaging the subsidiary totalizers and comprises a bell-crank 128, Fig. 19, rocked at the end of the first and second periods of each operation by a cam 130 on the main shaft 3. A hooked lever 126, mounted on the bell-crank, co-operates with the lug 111 on the grand totalizer frame and is controlled by a stop 132 on a lever 133, that is in turn controlled by a lever 135 connected by a spring 148 to an arm 143 of the differential shaft 20. In adding operations, the stop 132 is displaced after the first period to render the engaging hook 126 effective and is restored to disabling position prior to the second excursion of the hook. In total and subtotal taking operations, the lever 135 is variously controlled by an arm 145 set by a slot 147 in the operation control cam-plate 7, as described below. Printing totals. A total-taking operation is initiated after the setting of the control lever, Fig. 29, to the position E or F to select the grand or a subsidiary totalizer, respectively. The first period of a total-taking operation is similar to that of an adding operation and includes the clockwise resetting of the actuators 21, Fig. 1, by the arms 36 of the shaft 20. As the selected totalizer is engaged at the end of the first period, means under the control of the operation control cam-plate shift a comb-shaped key 64 axially of the selected totalizer shaft 46 to locate projections on the key in the paths of internal teeth 44a on the totalizer wheels. During the second period of the operation, the totalizer shafts which are permanently geared to the shaft 20, receive a counterclockwise rotation with the result that that totalizer which is engaged with the actuators is reset and rotates the actuators clockwise past the reset position through angles commensurate with the totalizer setting. During the first period of an operation following a total-taking operation the actuators are restored counterclockwise to normal position by wheels 55 in constant mesh therewith, the shaft 107 carrying the wheels 55 receiving at this time a clockwise rocking from the shaft 20 that, through a key 106 on the shaft, is transmitted to the wheels through internal teeth 55a. The totalizerengaging mechanism operates in total-taking operations in precisely the same manner as in adding operations. Printing subtotals. In taking a subtotal, the selected totalizer is re-engaged with the actuators at the end of the second period of the operation so that the total is returned from the actuators to the totalizer wheels during the first period of the succeeding operation. The grand totalizer is selected for subtotal taking by adjusting the control lever, Fig. 29, to the position J, in which position the arm 145, Fig. 19, is set by the slot 147 to intercept a stud 137a on a lever 137 flexibly mounted on the lever 135. The clockwise rocking of the arm 143 causes the lever 137 to rock counterclockwise and remove its abutment 141 from the path of a stud 142 on the arm, so that upon the return of the latter, the arm 135 remains in rocked position in which the stop 132 is disabled and the totalizer is re-engaged by the hook 126. When the control lever is adjusted to one of the positions, H, F to take a subtotal or total from a subsidiary totalizer, the arm 145 is set to intercept a pin 136 on the lever 135 and disable the grand totalizer engaging-mechanism. Control of keys by operation control lever. The item-characterizing keys 4, Fig. 23, cooperate by pins 175 with a detent plate 176. In adding and total-taking operations, the detent is rocked upwardly by a cam 203 to release the depressed key prior to the second engaging movement of the associated hook, 124, Fig. 17. On the other hand, in subtotaltaking operations the detent is controlled by a second cam 204 and the key is not released until after the totalizer has been re-engaged. The connections between the detent and the cams include an arm 181a on a shaft 182 rocked by a lever 183, the lower end of which is slotted to receive a stud 187 positioned by a slot 193 in the operation control cam plate 7 so as to co-operate with one or other of two levers 194, 195 rocked by the cams 203, 204, respectively. The rotation of the operation lever to one of its extreme positions, to select the grand totalizer for total or subtotal taking, rocks the shaft 182 counterclockwise to release any key that may be depressed and raises the detent a sufficient extent to lock the keys by means of the offset parts 177d of the slots therein. Movement of the operation lever to any total or subtotal position releases all depressed amount keys and locks all the amount keys in raised position. Printing-mechanism. The actuators 21, Fig. 1, are connected through pinions 48 and nested sleeves 49 to typewheels 8, Fig. 5. As the actuators rotate in opposite directions in adding and total-taking operations, each type-wheel is provided with two sets of type having a common zero. The sets of type are preferably of differing natures to distinguish totals from items. Totals, subtotals and items are further distinguished by characters printed from a type-wheel set by the operation control lever. Differentially moved indicators. The items and totals are indicated to the operator and purchaser by drums 10, 11, Figs. 1 and 13, geared to the actuators and visible through windows 52, 58 in the casing. As the drums rotate with the actuators in opposite directions in adding and total-taking operations, each drum is provided with two sets of numerals arranged as shown in F ig. 15. A shutter 59 extends across each window and is adjustable to render either set of numerals visible. The shutter is operated through a bell-crank 93 and stud 92 by a hook 91 carried by