Patent GB-536644-A (GB)
Title: Improvements in or relating to accumulators for calculating machines
IPC: G06F7/46
Filed: 1939-11-16
Abstract: 536,644. Calculating and statistical apparatus. BRITISH TABULATING MACHINE CO., Ltd. Nov. 16, 1939, No. 30229. Convention date, Nov. 16, 1938. [Class 106 (i)] An accumulator particularly suitable for use in a record-card controlled machine comprises for each denomination a set of value-retaining relays, one for each digit, cyclically operable commutating means for preparing the energizing circuits of these relays in succession at a point in the cycle of the commutating means corresponding to the digit associated with the relay, a group of value-accumulating relays, one for each digit, each arranged to advance or retard the point in the cycle at which the energizing circuit of each value-retaining relay is prepared by the commutating means to an extent corresponding to the value-accumulating relay digit, and means for restoring any energized value-accumulating relay to normal after the last point of a cycle, energizing the value-accumulating relay corresponding to the value-retaining relay in that cycle and restoring the energized value-retaining relay. As applied to a perforated cardcontrolled machine the cards are fed past an upper roll 231, Fig. 5a, and a lower roll 220 and group control column brushes are wired to group control magnets GC with holding magnets GCH, so that if a card grouping agrees with the following card the magnet is energized to prevent total taking by opening a contact 270 of a set which may be plug-connected in series through jacks JGC and plug sockets 272, 273, and 274 with major, intermediate, and minor group control magnets MA, INT, and MI for stopping adding and automatically taking a total. An adding and a subtracting commutator are provided for each denomination similar in construction but driven in opposite directions. That for adding has a non- conducting disc 42, Fig. 2, with conducting rings 47 connected to peripheral segments 46 to contact with brushes 43, brushes 45 on a block 49 mounted in brackets 44. The segments 46 pass the brushes 43 synchronously with the passage of digit points on the cards past the brushes 75. The circuit for the units denomination has a column of valueretaining relays 0u, 1u, 2u ... 9u with on the right of it a developed adding commutator 43, 45, 46, 47 and to the right of that a developed subtracting commutator 62, 63, 65, 66 and to the left of the column of valueretaining relays a column of value-accumulating relays ROu, Rlu, R2u ... R9u. The entry circuits to the commutators are shifted under the control of amounts stored in the valueaccumulator so that each new amount entered is stored with that already standing on the value-accumulator relays. Thus if the valueaccumulating relays stand at zero an addition entry of 4 comes from the brush 75 to a plug socket 70 and is directed to the 4u relay-closing contacts 4ul for holding, 4u2 to energize valueaccumulating relay R4u and prepare a carrying circuit at 4u3, the relay R4u setting up its own holding circuit at R4u-1, an entry circuit at R4u-2, a carrying circuit at R4u-3, a subtracting circuit at R4u-5 a reading-off circuit at R4u-6, Fig. 5a, for printing. Thus an addition of 5 to the 4 amount already on the accumulating relay R4u is directed to the 9u relay and a subtraction entry of 3 would go to the lu relay. Transfer mechanism.-To the left of the column relays R0u, R1u ... R9u are shown the carry circuits, and shortly after the new entry is added a carry test circuit is made at RC16 while the old amount is standing in the series R0u, R1u-3 ... R9u-3 and the unit digit of the sum thereof with the new entry (directed through the circuits controlled by the ROu .. R9u as above described) is first set on the series 0u3, 1u3, 2u3 ... 9u3 and if this digit is smaller than that standing in the accumulator relays a circuit is made through relay 20u which closes contacts 20u-3, Fig. 5c, in the tens commutator circuits. The set-up in the tens value-accumulating relays R0t, R1t &c. is momentarily removed by cam contacts CR19 and relay 25 to allow the set-up for the addition of one in the tens to be completed by cam contacts CR 14 causing the R1t relay to be energized and held, after which the contacts CR15 open to deenergize the relay 1t. Corresponding circuit arrangements allow the carry to proceed through a 9 standing on the tens value-accumulating relays to the hundreds and so on. Subtraction quantities are indicated on the card by a special perforation at an " 11 " point on the card read by a brush 230 in the upper bank UB which through a magnet SSP, Fig. 5a, holding magnet XGH cam contacts CF13, and CF23 energizes a relay CSS to cause contacts CSS-1, Fig. 5b, to put the subtraction commutator in circuit. In a manner similar to the carry " for additions above the " borrowing " for subtraction is effected on closing of the carry test contacts CR16, the contacts CSS-20, Fig. 5b, being now shifted so that a new value in the units being greater than the old calls for a negative carry and energization of the relay 20u. At the end of the additions or subtraction the holding circuits to the relays Ou, 1u, 2u ... 9u employed are opened. Total taking under minor group control, the socket 274, Fig. 5a, being connected to a jack JGC. Disagreement of control number between a pair of succession cards energizes the magnet MI which closes contacts MI2 energizing the total magnet TM and printing clutch magnet PCM. Total taking under minor, major, and intermediate controls is as described in U.S.A. Specification 2,079,418. According to the value-accumulating relays holding the amounts ROu-6, R1u-6 &c. or for units R0t-6 &c. for tens ROh-6 &c. for hundreds have been selectively set and differentially transmit through an emitter 67 the amounts to printing magnets PM in known manner. At the end of the print cycle the value-accumulating relays are de-energized after which contacts 80a, Fig. 5b, 80b and 80c, Fig. 5c, are closed to set up zero again in the accumulator. The card feeding mechanism is generally similar to that disclosed in Specification 375,889.