Patent GB-611478-A (GB)
Title: Improvements in or relating to record-card controlled accounting machines
IPC: E02B8/02
Filed: 1946-05-01
Abstract: 611,478. Statistical apparatus. BRITISH TABULATING MACHINE CO., Ltd. May 1. 1946, No. 13229. Convention date, May 15, 1945. [Class 106 (i)] A cyclically operating calculating machine controlled by record cards in which a digit is represented by one or more holes in a column in combination, comprises an electromagnetically operated accumulator and is characterised by means for sensing simultaneously all the holes in a column partially to complete through them the operating circuit of the accumulator, and by a commutator adapted to complete the circuit at one or more times in the cycle. In the embodiment described, the card, Fig. 7, comprises two fields, and digits are represented by a two-position code as shown. A perforation in the " X " position conditions the machine for subtraction. Card feeding. A cam (not shown) on a shaft 18, Fig. 1, oscillates a follower member 29 and, through linkage 31, 32, reciprocates a slide 35, comprising a picker blade 36, to feed the cards one by one from a magazine 38. The card feed is taken up by a pair of belts 57 co-operating with guides 63 and pressure rollers 90. Three card stops 78, 79, 80, operated by cam means through a follower 71, link 73 and bellcranks 72, serve to locate the cards exactly during the sensing operation. A known stacking device 85 transfers the cards to a hopper 86. Card reading. While the cards are held stationary by stops 79, 80, Fig. 6, they are sensed by brushes 96, 97 which co-operate with contacts 102 in insulating blocks 101 to partially complete a circuit to the totalizer in each case where a perforation occurs in the card. Commutators 107 complete these circuits as brushes 105, 106, rotating with shafts 46, 51, pass over contacts 104 connecting them through further brushes 108, 109 with common conducting segments 107. Totalizer. A known type of totalizer, Fig. 8, comprises means for clutching each denomination wheel to a constantly-rotating shaft 118 under the control of a lever 111 which is pulled to the declutching position (shown) by energization of a magnet SM and to the clutching position by energization of a magnet AM. In the case of addition, as an LB commutator brush 106, Fig. 6, passes over contacts 104 representing the digits 2, 1, 2, 5, and where the presence of a perforation in the card allows the completion of a circuit, the corresponding AM magnet receives an impulse causing the clutch to be engaged and the totalizer wheel to be driven until one of three knock-off pins 135, 136, 137 engages the lever 111 to cause declutching. This may occur up to three times in one cycle whereby the equivalent of any digit 1 to 9 may be entered. Cam means on the totalizer wheel moves a contact 142 when the wheel passes from 9 to 0, thus providing a circuit for the AM magnet of the next higher denomination. A knock-off pin 153 causes declutching in this case. Where an item is to be subtracted, a perforation is provided in the " X " position. This perforation is sensed at the UB station and causes the AM magnets to be energized automatically to add successively the digits 2, 2, 5, but declutching by magnet SM under the control of the card analysing commutator LB107 causes the complement of the digit to be entered. In the usual way a carry from the highest denomination is transferred to the units to account for the " fugitive one." Each denomination of the totalizer comprises a read-out commutator and is reset to zero by impulses from a common emitter co-operating with the read-out commutators.