726,703. Accounting machines. NATIONAL CASH REGISTER CO. March 18, 1953 [April 4, 1962], No. 7502/53. Class 106 (1). An accounting or similar calculating machine, provided with mechanism for suppressing zero prints in the higher orders, has means for modifying the action of this mechanism when entering non-additive data covering a restricted range of printing orders, so that zeros are suppressed in the unused orders both above and below that range but not within the range itself. The invention is applied to a machine for handling telephone accounts ; subscribers' numbers are entered mainly on the four lower dollar banks of the amount keys 100, Fig. 2, and zeros are printed in all those orders, but are suppressed in the generally unused two decimal orders as well as in the highest order. Two additional key banks 99 are provided for setting exchange identification letters, for which corresponding digits are printed. The control keys include a " Telephone No. " key 101, which brings into action the modified zero print suppression, and a " Notifier " key 111 for printing a subscriber's number and the amount of an overdue account, which has just been met, on an issuing tape for immediate transmission to the accounting department. Amount keyboard and differential mechanism. Coacting with each bank of keys 100 are a flexible detent slide 260 (Fig. 3), a slide 261 for controlling release of a zero stop 271 by a bail 272, a locking slide 262, an interlocking slide 263 and a differential stop bar 290. Associated with each stop bar 290 is a type-setting slide 466 which is connected through gears 497, 500 and interconnected ring gears 501, 502 with a related type wheel 465 in each of three printers. Rearward followed by return forward movement of a universal rod 310 during a machine cycle releases the bars 290 to their springs 307 and then restores them, the stroke of the slides being limited according to the set keys and the return movement being transmitted to one or more totalizers 350. During its rearward movement, the universal rod 310 picks up the typesetting slides 466 and moves them one step beyond zero into an " eliminated " position in which the type wheels 465 present a blank space or a dash at the printing line. Pawls 468 then couple the type-setting slides 466 to their stop bars 290 so that the setting of the stop bars is transferred to the slides 466 as the stop bars are restored. Suppression of zeros for additive data. To suppress a zero occurring in any order, the stop bar 290 is restored from the zero position, in which it is held by the zero stop 297, back to its normal home position in advance of the universal rod 310 and before the pawl 468 is operated to couple the bar with the type-setting slide 466. The type-setting slide 466 is then left in its " eliminated " position in which a zero is not printed: To effect this early return of the stop bars, each has associated with it a resetting pawl 531 carried by a cam-slotted lever 533 actuated by a roller 541 on the carrier arms 311 of the universal rod 310. A stud 538 on the arm 311 normally holds the pawl 531 inactive, but releases the pawl to a spring during the initial part of the forward stroke of the rod 310 so that the pawl can then engage behind a step 543 in the stop bar 290. This, however, can only occur if the stop bar is in its zero position since, otherwise, a pin 540 on the stop bar releases a latch 536 to hold the pawl 531 depressed and inactive. During the continued forward stoke of the rod 310 and of the roller 541 in the cam slot 542 of the lever 533, the pawl 531 is carried forwardly (to the left, Fig. 3) and, if engaged with the step 543, restores the stop bar 290. The pawls 531 are formed as yokes and overlap one another by means of projecting ears so that a pawl 531 held inactive by its latch 536, due to its stop bar advancing beyond zero, also holds lower order pawls 531 inactive. As a consequence, zeros are not suppressed in orders below one in which a digit has been set. However, the dollar pawl 531 does not overlap the dimes pawl; instead, a latch 2150 (Fig. 14) normally engages over the dimes pawl to hold it and the cents pawl inactive so that decimal zeros are always printed when additive data is being entered. Suppression of zeros for non-additive data. Td effect the modified control of zero printing when entering subscribers' numbers, a cam 2154 (Fig. 14) is rotated to disengage the latch 2150 from the dimes and cents resetting pawls 531, which then become active to suppress zeros in these two orders. A second cam 2195 (Fig. 15) is also rotated and this releases a latch 2190 to engage over the fourth dollar order resetting pawl 531 so that this and the three lower dollar resetting pawls 531 are held inactive, and zeros are printed in those four orders. The cams 2154 and 2195 are rings with internal teeth and are rotated in unison under control of the " Telephone No. " key 101 by means of pinions on a square shaft 2157. Further pinions on the shaft 2157 mesh with internally toothed rings 2160 and 2175 (Fig. 13), the ring 2160 having external teeth gearing with a pivoted segment 2165 normally blocked by an arm 2167, whilst the ring 2175 is adapted to be rocked clockwise by a spring-actuated lever 2178 under control of a cyclically operated cam 562. With the key 101 undepressed and the segment 2165 blocked, the discs 2154 and 2194 remain in their normal positions shown (Figs. 14 and 15) for the normal zero suppression action. Depression of the key 101 releases the segment 2165 so that, at an early stage in the machine cycle, the lever 2178 is able to rotate the ring 2175 clockwise, the cams 2154 and 2195 rotating with the ring 2175 and reversing the latches 2150 and 2190 to modify the zero printing as above stated. In repeat operations it is necessary for the differential slides 2190 to remain in their key-set positions, and the resetting pawls 531 for zero suppression must, therefore, be disabled. As regards the dollar orders, this is effected by a latch, similar to the latches 2150 and 2190, which is moved to engage the highest order resetting pawl 531 upon depression of the " Repeat " key 114. The decimal order pawls are normally latched down and ineffective provided the " Telephone No. " key 101 is not operated : to ensure this, an interlock is provided between the keys 101 and 114. Machine locking. Printing cashier's symbol. An ear 2231, Fig. 18, on a link 2232 normally blocks a machine release link 939. A cashier's key 2210, Fig. 22, inserted into a slot 89 forces the link 2232 rearwardly by engagement with its cam-shaped forward end 2236, a second ear 2239 on the link then blocking the release link 939. Upon full insertion of the key, the cam end 2236 of the link snaps into a slot 2237 in the key and both ears then clear the link 939 permitting the machine to be operated. A block 2225 is shaped and positioned on the key to set identification digits for the cashier at the printing line. This block is adapted to depress differentially two slides 2212 which are racked for driving a train of gears connecting with the cashier's number type wheels. A rod 2224 engages inclined slots in the slides so that the slides are tilted to engage fingers at their upper ends in slots 2226 in the key beneath block 2225. By this means the slides are restored as the key is withdrawn.. To prevent fraudulent release of the machine by partial insertion of a key sufficient to clear both ears 2231 and 2239 from the release link 939, a second key-operated link (not shown) is adapted to block the release link temporarily during key insertion. This ensures full insertion of the cashier's key and that only his own number is printed.