423,169. Calculating - apparatus. BURROUGHS ADDING MACHINE CO., 2nd Avenue, Detroit, Michigan, U.S.A. June 24, 1933, No. 18088. Convention date, Oct. 3, 1932. [Class 106 (i)] Adding and subtracting apparatus.-In a machine with an adding and subtracting totalizer means are provided to enable true negative totals to be taken. On a change of the totalizer from positive to negative condition, manipulative members such as the total keys are locked and the depression of a special release key is necessary to condition the machine for a total-taking operation. The operation of the release key serves to insert the " fugitive 1," to release the total keys, condition the machine for subtraction, and initiates an operation of the machine. A total or sub-total is taken during the next operation on depression of the appropriate key. The invention is shown as embodied in a machine of the Burroughs portable type as described in Specification 265,122, [Class 106 (i)]. The totalizing register is of the tumbler type having geared adding and subtracting pinions 10, 20, Figs. 1 and 3, mounted on shafts supported in a frame 12 with studs 13 journalled in the arms 14 of a main frame rockable about a shaft 15 by a cam 16 operatively connected to the main shaft 6. The shaft 6 may be hand-operated or be oscillated by connections with a motor operated shaft 7. To one of the studs 13 is secured an extension 48 carrying a plate 47 with studs 46, 51 adapted to co-operate with notches in spring-controlled latch arms 40, 41 pivoted to the frame 14 to hold the totalizer in add or subtract position respectively. The setting of the totalizer to the add or subtract position is under the control of an arm 39 of a pivoted yoke member 37 movable to one or other of two positions, to condition the totalizer during its movement into engagement with the differential actuating sectors 3, under the control of the + or - starting bar. Depression of the " + " bar lowers its slide plate 25 to move downwardly, through a stud 27, the motor control plate 28 to cause the motor to give the machine an operation cycle. The plate 25 has an arm 34, which under certain conditions engages a stud 35 on an arm of the yoke member 37. With the totalizer in the add position and the " + " bar depressed, the arm only contacts with the stud. If, however, the totalizer had been left in the subtract position, it will be tumbled to the add position as it moves to rack engaging position, since the arm 39 in its upper or normal position abuts against the stud 51 during this movement. Depression of the " - " bar lowers its slide plate 60 and through a pin 62 moves the motor control plate 28. The plate 60 has an extension 63 which contacts with a stud 64 on a yoke member 66 to rock the arm 39 through a pin- and-slot connection 69. If the totalizer is, at the time, in the subtract position, the lowering of the arm permits the totalizer to retain its position ; if the totalizer is in addition position the arm 39 frees the latch 40 and abuts the pin 46 to cause the totalizer frame to rock. The arm 39 is normally held in the add position by a spring 68 acting on the yoke member and is latched in the subtract position by a latch 73 engaging a pin 72 on a link 70 connected to an arm of the yoke member. A projection 76 on the latch co-operates with the stem of the error key E. Release of the latch is delayed until the end of the machine operation by the provision of a yoke 82 and latch 88 co-operating with a stud 87 on the link and held in blocking position until the usual control slide 80 is returned to forward position, a pin 94 thereon freeing the latch. The latch 73 is rocked on the rearward movement of the slide 80 by the known control rod 78 to condition the link for subsequent release by the latch 88. Total key lock. The pinions 10, 20 of highest denomination have projections 100, 101, for co-operation with the noses of pawls 103, 106, pivotally mounted on the frame 14 and interconnected by pin and slot 108. The pawl 106 has a forward projection 115, Fig. 4, underlying the end of a lever 117 connected to an arm 120 on a shaft 121, another arm 122 of which engages a lug on a lock plate 124, Fig. 6, for the total keys. Under normal conditions the total and sub-total keys T, ST can be depressed as their stems are free to pass through notches 127, 128 in the lock plate. If a negative total occurs, the projection 100 rocks the pawl 103 and causes the arm 122 to displace the lock plate to lock the total keys against depression. The lock plate may also be positively moved forward by the provision of a pin 130 on the subtraction slide 60 engaging a cam projection 131 on the plate. The change from negative to positive condition releases the lock plate. On the rocking of the frame 14 to put the totalizer pinions into engagement with the sectors 3, the arm 115 is moved slightly so that the lever 117 moves sufficiently to displace the lock plate to lock the total keys. Release key and connections. A release key 140 is provided which is normally locked against depression by the plate 124, but when the total keys are locked the release key may be depressed. Depression of this key (1) inserts the " fugitive 1," (2) releases the total keys, (3) conditions the machine for subtraction, and (4) causes an automatic operation. (1) The units order pinions have a segment 150, Fig. 3, similar to the transfer segments which can be engaged with one or other of the pinions 10, 20. The segment has an upwardly extending arm 152 with a lug 157 engaging a latch 155, the latch being provided with a pin 158 co-operating with an arm 159 of a yoke member 160. Another arm 162 of the yoke is connected to a lever 163, the forward end of which underlies the release key 140, Fig. 4. When the release key is depressed the latch frees the segment which under spring action would be moved to insert the " fugitive 1," such movement is governed by a second latch 170 forming part of a yoke member 172. To the other arm of the yoke is secured a stud 173 co-operating with one or other of the recesses in arms 180, 185 pivoted to a four-armed lever 175, the other arms of which carry slotted links 177, 178 engaging over the totalizer pinion shafts. The movement of the arms 180, 185 is limited by pins 182, 187 projecting from a pivoted plate 183. When the totalizer is rocked from the add position as shown in Fig. 7 to the subtract position the lever 175 is rocked to raise the arm 180 which rocks the yoke 172 to release the latch 170 leaving the segment 150 under the control of the latch 155. Other items may be subtracted because the latch 155 is only released by depression of the release key. If items are added the totalizer frame is rocked and a projection 165 thereon by its engagement with a tail 166 of the latch 155 will free the latch during the machine operation; no " fugitive 1 " is entered, as the latch 170 is restored by the rocking movement, unless the negative total has been taken. To control this condition the segment arm 152 is engaged by projections 201, 202 of an arm 200 carrying a stud 203 that co-operates with the ends of the arms 180, 185. On depression of the release key the segment is rocked and the stud 203, lying in the path of the end of the arm 180 with the totalizer in subtract position, displaces the arm to free the latch 170 and to rock the plate 183 which moves the arm 185 to the position shown in Fig. 9. On the restoration of the segment therefore the latch 170 falls into latching position. As the totalizer is in the subtract position after taking a negative total, if items are to be added the totalizer frame will be rocked to add position and the projection 165 will free the latch 155, and the plate 175 will be rocked to raise the arm 185 from the position in Fig. 9, so as to free the latch 170 and thereby release the segment to enter the " fugitive 1 " in the add direction. During this operation the stud 203 engages the end of the arm 185 and the plate 183 is rocked to its other position. (2) When the plate 183 is rocked on depression of the release key a pin 189 on the plate rocks a yoke member 212 having an arm connected by a spring 214 to a lever 215, one arm of which engages the rear end of the lock plate 124 so as to move it forward by the action of the spring 214 when the release key is restored to unlock the total keys. The lock plate is held forward by the lever 215 until the totalizer goes to positive condition when the yoke 212 is restored by the plate 183. The lock plate is then free to return to normal position as the lock lever 122 is also released. If the totalizer remains in negative condition, the arm 122 prevents return of lock plate to normal so that total keys are locked but release key is freed. (3) The lever 163 underlying the release key has an abutment adapted to co-operate with a pin 220 on the plate 60 of the " - " motor bar so that the release key conditions the machine for subtraction. (4) Depression of the plate 60, as previously described, operates the motor control plate 28 to initiate an operating cycle. Negative total-taking operation. In normal operations a slide 232 mounted on an arm 233 is positioned so that an abutment thereon overlies a stud 236 on the plate 25 of the add motor bar. When a negative total occurs the " fugitive 1 " is entered, causing a movement of the lever 215 to push the lock slide forward and at the same time, through another slide 230, Fig. 6, adjusts the slide 232 so that the abutment overlies a stud 237 on the subtract motor bar 60. Specifications 265,134, 265,135, 265,136, 265,137, 265,140, and 265,152, [all in Class 106 (i)], also are referred to.