274,411. Burroughs Adding Machine Co., (Assignees of Pasinski, W. J.). July 19, 1926, [Convention date]. Adding and subtracting apparatus with several totalizers; printing totals and sub-totals.-An adding and subtracting machine is adapted for accounting operations by the provision of an additional or lower counter 70. Fig 3, whereby amounts entered in or totals accumulated upon the ordinary add-and-subtract totalizer 20, 21 may be accumulated upon or entered in this additional counter and vice versa. Moreover, means are provided for preventing the taking of a negative total with the machine in adding condition and, conversely, the taking of a positive total with the machine set for subtraction. The various controls may be exercised by keys or automatically as described in Specification 193,455. Additional counter, construction of. The pinions 70 constituting this counter are mounted on a sleeve 71. Fig. 4, by means of ball bearings the balls of which are confined between a pair of ridges on a hub member 77, one ridge being formed by spinning and crowding up after assembly of the pinions. The sleeve 71 is mounted - on a shaft supported between end plates 78. 79 secured to the shaft 80 adapted to be rocked to engage the pinions with the actuating racks. lengthened for this purpose. Additional counter, engagement mechanism for. Slidable on shaft 80 is a yoke member 81 one arm of which is perforated to receive a rod 84 forming part of the counter frame. The yoke is extended upwardly and downwardly to support spring-controlled one-way pawls 85, 86 carrying rollers 87, 88 respectively to co-operate with cam arms secured to the rock-shaft 800. These cam arms are disposed in different planes (see Fig. 6) and in pairs at different distances apart so that by the lateral positioning of the yoke the counter engagement can be brought into different timing relation with the operation of the machine. Normally, that is, for adding amounts on the counter, the rollers are in the plane of thecam arms 94, 95 so that as the shaft 800 is rocked counterclockwise (forward stroke) the arm 94 will pass idly by pawl 85 but eventually the arm 95 will bear on pawl 86 and rock the frame to engage the counter with the racks in readinessfor the return stroke. At the end of this stroke cam 94 becomes operative upon pawl 85 and restores the counter to its disengaged position. Taking totals and sub-totals from the additional counter. The engagement of the counter with the racks is controlled for total-taking by the cam surfaces 96, 97 (Fig. 6) and for subtotal taking by the surfaces 98, 99, these various surfaces co-operating with the one-way pawls 85, 86 to control the time of engagement in accordance with the usual practice. The yoke 81 supporting the pawls is shifted axially, for selection of the cam surface to be effective, by means of a bell-crank lever engaged bv the lower end of a lever 102, Fig. 1, the upper end of which is piloted to a setting-lever 104 capable of manual displacement towards the front and rear, from the normal central or adding position, for total and sub-total taking purposes. The lever 104 is retained in set position by a notched latch 106 engaging a stud I07 on the lever and rocked by the usual bail 202 to release the lever at the end of the cycle. The lever when thus freed is restored to its normal position by the action of a pincer-like pair of spring-controlled levers 110 embracing a pin 112 on an arm of the lever 104. The usual total or sub-total key of the machine is employed in conjunction with the setting of lever 104 for taking totals or sub-totals from the lower counter. When the control lever 104 is shifted forward or backward a stud 210, Fig. 11, upon it operating in a cam slot rocks a lever 211 connected to a pitman 213 having an ear engaging behind the usual link 63 so as to shift this forward until a long slot therein co-operates with the pin 62 on the total key 60. Depression of this key therefore will release the racks as usual, but the link 63 will not be affected and therefore the upper counter will not be engaged. Non-computing. A key 170, Fig. 1, when depressed prevents action of the upper counter by lowering a lever 175 so as to disable the link 28 by placing it below the path of the oscillating stud 26 and thereby preventing engagement of the counter at the end of the forward stroke. The lever 175 also effects the disablement of the pass-by pawl 821 to prevent engagement of the counter by the pitman 914. A non-computing key 180 for the lower counter is also provided and when depressed rocks a lever 183 pin-andslot connected to a link 186. Fig. 3, having a stud 187 engaged by a spring-controlled bell-crank 188 pivoted at 189 and having an extension to cooperate with the pawl 86. Another bell-crank 192 also pivoted at 189 and engaging the stud 187, extends upwardly at 193 to co-operate with a stud 194 on the oscillating arm 813. The rearward movement of link 186 effected by the key causes the stud 187 to pass between the coaxial bellcranks and the arm 193 enters the path of stud 194 so that near the end of the forward stroke the bell-crank 192 is rocked clockwise and through the extension of the other bell-crank dis. places the pawl 86 to prevent the engagement of the counter. To prevent depression of the key 180 when the total-control lever 104 is out of central position, and vice versa, a notched lateral extension 198, Fig. 11, of the key stem co-operates with a stud 199 on the lever 104 to produce the necessary interlock. The non-computing condition of either or both counters may also be controlled automatically by the position of the carriage. For this purpose rollers of varying diameter may be located on the carriage to effect differential depression of a yoke 200, Fig. 1, extended at 201 to operate the lever 183, Fig. 3. The smallest degree of displacement of this lever disables the lower counter in the manner just described. A larger displacement causes a stud 182 on the lever to ride up a raised surface 204, Fig. 1, on lever 175 and thus disable the upper counter, the stud 187 still remaining effective upon the bell-cranks to render the lower counter also inoperative By the use of the largest diameter roller the link 186 is shifted to the left sufficiently to place the stud out of contact with the bell-cranks so that only the upper counter is in non-computing condition. Interlocks. (1) The subtraction lever 30, Fig. 1, and the lower counter total control lever 104 are interlocked so that the former cannot be moved when the latter is out of central or adding position and the latter cannot be moved when the subtraction lever is in certain positions. Pivoted to the subtraction lever at 220, Fig. 17, is a pair of connected Y-shaped levers one of which, 221, is hooked to engage a pin 222 on the lever 211 displaced whenever the lever 104 is shifted from central position. Normally, the parts are positioned as in Fig. 1, but when lever 30 is moved to " subtraction, Fig. 17, the pivot at 220 is carried to the right and as one of the Y- shaped levers is pin-and-slot connected at 225 to the lever 35 the Y levers are rocked counterclockwise and the pin 222 is seized, thus preventing movement of lever 104. If the machine is operated with the lever 30 in subtraction position the consequent displacement of lever 35 throws the Y levers to the right to free the lever 211. The lever 104 could now be shifted, but due to the construction of the machine two spacing strokes must first be given, as described in Specification 9102/13, a bail being held to the rear by any transfer pawl latches still displaced and causing a blocking of the lever 104. Similar interlocking effects obtain when the lever 104 is displaced with the lever 30 in either of its positions. The square stud 229 on lever 30 prevents movement of lever 104 unless lever 30 is right forward or right back, due to the obstructing effect of the end 227 of lever 211. (2) The upper counter non- computing key 170 cannot be depressed when the lever 30 is in subtraction position. A lug 235, Fig. 13, on link 172 pivoted to lever 30 passes beneath a pin 171 on key 170 so that if the lever is in subtraction position the key is blocked. Similarly, with the key down the lever 30 cannot be moved forward. (3) The lower counter total lever 104 cannot be shifted while the total key 60 or sub-total key 65 is depressed for a lug 240. Fig. 11. of the link 213 then stands in front of a stud 241 on the lever rocked by the total or sub-total key and so prevents movement of the lever 104. (4) Depression of the total key or sub-total key prevents depression of the non-computing key 170 of the upper counter owing to a shoulder 251 on a link 250 connected with the former keys being positioned beneath a stud 252 on key 170. If this key should be depressed first the link would not be obstructed by the stud but a pawl 253, Fig. 11. on lever 175 moved by thq key comes into obstructive relation with a stud 254 to stop the link from moving to the left. If under these conditions it is desired to take a total from the lower counter the total lever must be released and for this purpose a latch 106, rocked bv movement of the total control lever 104 displaces the pawl 253 to free the link 250 and therefore the total and sub-total keys. (5) With the total key depressed the subtraction lever 30 cannot be moved, owing to the obstructive relation of the pin 241. Fig. 17. and the enlargement 260 of the lever 30. When the lever is at " subtraction " the total key cannot at first be depressed owing to stud 261, standing above an arm of the Y lever 223. After the required spacing strokes, however, the Y lever is displaced to permit use of the key. Similar conditions obtain when the subtraction lever is moved to adding position. Printing characteristic symbols. The characteristic type segment is provided with extra steps and