Patent GB-284713-A (GB)
Filed: 1928-02-03
Abstract: 284,713. British Tabulating Machine Co., Ltd., (Assignees of Carroll, F. M.). Feb. 4, 1927, [Convention date]. Statistical apparatus; printing totals and subtotals.- The recordcard-controlled statistical machine described in Specification 280,580 is modified for subtraction. Separate counters for minuends and subtrahends have normally inoperative connections between them, these connections, when called into operation, transmitting the amount on the subtrahend counter to the minuend counter in such manner as to diminish the amount on the latter by the subtrahend amount. The inoperative connections include a special receiving counter, the complement of the subtrahend amount being transmitted to this receiver which subsequently retransmits this complement to the minuend counter. Total and sub-total printing takes place at the various stages, the minuend counter being finally reset to zero after the final difference is printed. The receiver accumulator unit, Fig. 23, and the minuend and subtrahend accumulators, are constructed the same as the accumulators of. the prior Specification, but are controlled differently. There may be a subtraction unit for each denomination, each such unit comprising usually a minuend accumulator unit, a receiver unit, and a subtrahend accumulator unit. The lever 641, Fig. 23, used in the prior case for transfer, coacts in the receiver unit not only with the cam members 644 but also with a stop magnet 642, which when energized unlatches lever 635 and relieves the tension on spring 632 operating the clutch member 628. If, when the magnet 642 is energized, the clutch happens to be in, a lug 636 on lever 635 raises an arm 665 of lever 629 to throw out the clutch. The spring 632 is retensioned towards the end of each cycle by a lever 652 being rocked clockwise by a notched shaft 653; this shaft is operated by mechanism similar to that which controls the shaft 147 co-acting with all counters except the receivers. Fig. 25 shows a debit accumulator unit (minuend) 151<d>, a credit unit (subtrahend) 151<c>, and a receiver unit 655. The connections are shown as permanent for convenience; many of them may be through plug-boards. During a subtracting operation the necessary circuits are controlled for six machine cycles by a subtraction timer similar to the total timer shown in Figs. 21 and 22 of Specification 280,580, the cams being modified to give the required sequence of operations. Total timer contacts have the prefix F, subtraction timer contacts the prefix H, and ordinary instantaneous point control contacts the prefix R. A subtracting operation is initiated by the operation of the automatic total timer which partly overlaps the totalling which automatically takes place when the cam group changes. In its second cycle of operation the automatic total timer energizes the magnet 537, Fig. 25, to cause the sub-totalling switch bar 93 to close its contacts; the sub-total of the debit unit is thereby printed by means of circuit 490, R2, 681, 93, 682, counter magnet 151d, 683, and 491; printing takes place as the counter wheel passes through zero, as in the prior case. During the third cycle of the total timer, contacts F7 close and contacts R11 cause energization, at the beginning of the fourth cycle, of the magnet 548 operating the totalling switch-bar 92. The magnet 151<c> is thereby energized to print the credit (subtrahend) total, this accumulator being cleared by the rocking of the shaft 147. Also, in the early part of this fourth cycle contacts H1 (closed in the third cycle) are still closed and contacts R19 close to energize the receiver magnet 655 one point later (to allow for the fugitive one) than the commencement of the operation of the credit accumulator unit. When the credit, unit reaches zero it closes contacts between the lines 687 and 688 and energizes, through line 692, the stop magnet 642 which then declutches the receiver unit. Thus the subtrahend (credit) total is printed, the counter cleared, and the complement with respect to nine transmitted to the receiver unit. During the fifth cycle of the total timer the magnet 655 is again energized by a circuit 490, R20, H2, 693, 655, 694, 491. The receiver clutch then moves the element 630 to zero, at which point a cam 644 rocks arms 672 and blade 673 to close contacts 679. At the same time the adjacent cam 644 rocks the lever 641 to relieve the spring 632 and declutch the receiver unit. The momentary closure of contact 679 closes a circuit 490, H3, 679, 702, 682, debit magnet 151<d>, 683, and 491; this energization of magnet, 151d throws in the debit (minuend) clutch, which is kicked out after adding the subtrahend complement from the receiving unit, since the kick-out cam on the sleeve 124d of the debit unit commenced to move at the moment the receiver clutch was thrown in. Thus if " 2 " were the subtrahend complement standing on the receiver unit, the latter will move eight points in restoring to zero. and during this time the kick-out cam on the debit unit sleeve 124<d> will likewise have moved eight points, and will disengage the debit unit clutch after the next two units have been entered into the debit unit. To allow for the fugitive one, an additional unit is entered into the debit accumulator during the next, or sixth, cycle through a circuit 490, R24, H11, 702, 682, magnet 151<d>, 683, 491. Contacts R24 are timed with respect to the clutch kick-out cam of the debit counter so that only one unit may be added. Printing from the debit counter usually gives a sub-total controlled from the sub-total switchbar 93, the shaft 147 maintaining the tension of the spring 142 of the debit counter. During the sixth cycle of the total timer, however, the switch bar 93 is controlled by contacts in the subtraction timer, which latter also rocks the shaft 147 to relieve the spring 142 so that the debit counter is cleared after the total of the difference has been printed. The circuit diagram of the machine (not shown) includes a special plugboard for connecting the receiver accumulator units as desired with respect to the remaining accumulators. A subtraction operation, may also be automatically initiated by closing a special subtraction switch which connects the subtraction and total timers. After preliminary circuits have been automatically closed, the circuits. are the same as described above with respect to Fig. 25.