399,217. Statistical machines. BRITISH TABULATING MACHINE CO., Ltd., Victoria House, Vernon Place, Southampton Row, London. April 1, 1932, No. 9438. Convention date, April 3, 1931. [Class 106 (i).] A record-controlled statistical machine has a pair of accumulators, means for distributing amounts read from the record selectively to the accumulators and means for comparing the totals on the two accumulators. If the totals are not identical, a warning is given, e.g. the record-card concerned is removed from the batch of cards. For example, in gas consumption a = b + c where a in the present reading of the meter, b the last reading and c the difference or consumption. The three terms a, b, c are punched in different fields of the same card ; a is added to one accumulator and both band c are added to the other, so that the comparing mechanism should subsequently find identical totals if the terms punched are correct. The comparing mechanism consists of commutator segments which coact with brushes geared to the counter wheels, the commutators of the two counters being wired together digit for digit in each denomination. The invention is shown as applied to a machine as described in Specification 247,200, [Class 106 (i), Calculating &c.], the cards being read by upper and lower brushes UB, LB. When start key ST is closed, cards are fed through the machine and upper card lever contacts UCL energize coils 22, 23 which close their contacts 22a, 23a ; and the lower card lever contacts LCL energize coils 20, 21 which close their contacts 20a, 21a. Contacts 21a, 23a supply current to the upper and lower brushes. The machine may be stopped by closing the key contacts 24 or automatically by the comparing mechanism, which energizes relay 18 to open its contacts 18a in the motor circuit ; relay 28 is simultaneously energized and by closing its contacts 28a automatically initiates resetting of the accumulators if switch 27 is closed. If this switch is open, reset key 29 is used. The counters are reset by zeroizing clutch magnets 75, Fig. 5a, energized by cam contacts 82 which are closed during successive tabulating cycles. When tabulating is interrupted only one of these contacts will be closed and the subsequent energization of coil 31 in the reset circuits closes contacts 31a to energize magnets 75 over the circuit 10, 31a, 82, 75, 83, 70, 69, 15. The closure of contact 82 is so co-ordinated with the tabulating cycles that resetting occurs for the counter (split into two accumulators) upon which the two totals do not agree. After the resetting, tabulating is restarted automatically on the next card if switch 34 is closed. There are three counters numbered 1, 2, 3 in Fig. 5b: for the totals-comparison each counter is split into two accumulators (upper and lower), each of five denominations. To check the equation a = b + c, a and bare entered by the upper brushes into the upper and lower accumulators respectively of a counter and c is entered by the lower brushes into the lower accumulator one cycle later. Splitting counters.-Magnets 36, Fig. 5b, control the entry in known manner of the amounts on to the counter wheels 48, Figs. 1 and 6, which are attached to indicator wheels 47. Wheels 48 mesh with wheels 49 which are loose on a clutch shaft 50 driven from shaft 51. There is a clutch between shaft 50 and each wheel 49 and a tripping arm 52, normally latched by armature 53 of a magnet 36, permits wheel 49 to be clutched to shaft 50 when magnet 36 is energized. When released, arm 52 is moved by a blade of a pair of contacts 43 which interrupt the circuit of magnet 36. The comparing mechanism is a commutator 55 with segments 56 against which rest one of a pair of brushes 57 geared to the wheel 49 so that the brush rests upon the segment corresponding to the number on the counter wheel. These parts are shown schematically in Fig. 5b; every segment 56 of the upper accumulator being wired by lines 60 to the corresponding denominational segment in the lower accumulator : these connections are only shown in Fig. 5b for the number 56789 as an example. The segments 59, Figs. 1 and 5b, are wired together as shown by lines 61. To split counter 1 into the pair of accumulators shown, the transfer is disabled between the 5th and 6th denominations. A transfer cam 62, Figs. 1 and 6, on each counter wheel 48 trips a member 63 to release a latch 64 which, during transfer time, is restored by a bail 65 and when so restored it advances the next higher wheel one step. The highest denomination of the lower accumulator has an auxiliary member 63a which normally engages latch 64, thus preventing its release and preventing transfer. If, however, it is desired to use the whole ten denominations .as a single counter during ordinary tabulation a switch 68, Fig. 5a, is closed to energize a magnet 66 which attracts its armature 67, Fig. 6, which thereupon rocks the member 63a awav from latch 64 which is therefore free to function normally at a transfer. The entry of amounts into the counters is controlled by coils 40, 41, 42 which operate contacts 40a, 41a, 42a, Fig. 5b. These coils are energized by contacts 86, 87, 88 which close during the entering portions of successive cycles. During the first cycle, with contacts 40a closed, the a and b terms, of the equation a = b + c punched on a card (A), are entered by brushes UB into the upper and lower accumulators respectively of counter 1: at the same time the term c from the previous card is entered into the lower section of counter 3. During the second cycle contacts 41a alone are closed, brushes UB enter the a and b terms from the next card (B) into the upper and lower sections of counter 2 and brushes LB enter term c from the previous card (A) into the lower section of counter 1. During the third cycle contacts 42a only are closed, a and b terms are entered into counter 3 and term c (card B) is entered into counter 2, lower section. Totals-comparison. This takes place in each pair of accumulators successively and in the cycle following the entry of the last term into that pair. Assuming for counter pair 1 that a = 56789 and b + c = 56789, the brushes 57 will occupy the positions indicated in Fig. 5b. Three contacts 91, 92, 93 each open momentarily in successive cycles after all the necessary entries have been made in their respective counter pairs. When all contacts 91, 92, 93 are closed they complete a circuit 10, 94, P5 (closed by a previous resetting cycle), 95, L6, 96, 97, 98, 93, 92. 91, 99, 15 to keep the machine in operation. Coil 95 closes contacts 95a to shunt contacts P5 and opens contacts 95b to de-energize coils 18, 28 so that resetting cannot take place. When a contact, say 91, opens memontarily, the above circuit through contacts 91, 92, 93 is maintained if the totals in upper and lower sections of counter 1 agree since a shunt circuit for contact 91 is made through 98, 93, 92, 103, 59 (lower units of counter 1), units brush 57, " 9 " segment, wire 60, " 9 " segment of upper section and so on backwards and forwards between the upper and lower sections until the circuit reaches wires 104, 99, 15. Hence as long as the totals on a counter pair agree the machine continues running. If a pair of totals disagree, the above shunt circuit is not completed and coil 95 is de-energized; contacts 95a open and contacts 95b close to energize relays 28, 18. Coil 18 opens contacts 18a to interrupt tabulating and coil 28 closes contacts 28a to initiate resetting of the appropriate pair of accumulators. During resetting, contacts P5 are reclosed to prepare the circuits for following totals comparison. Card-ejecting mechanism. When the totals in a pair of accumulators differ, a coil 102 is de-energized (as well as coil 95) and closes its contacts 102a to energize a magnet 105, Figs. 5a and 2. A rotary stacker 106 of conventional construction and driven from shaft 51, has clips 107 which receive the leading edge of the card after it leaves the lower brushes LB and carries it to a stack 108. When magnet 105 is energized its armature 109 releases a spring- pressed lever 110, the end 112 of which moves into engagement with a cam 111. At this moment the card is about to be engaged by clips 107 and the parts come to rest during resetting. When card-feeding is resumed the end 112 drops into a notch 113 of cam 111 and a rod 114 rigid with lever 110 rocks counterclockwise. Fingers 11 on rod 114 thereupon strike the leading edge of the card, stripping it from clips 107 and projecting it into a tray A. The machine according to the invention may also check the equations a + b = c and a + b = c + d.