Patent GB-549535-A (GB)
Title: Improvements in or relating to recording apparatus for statistical machines
Filed: 1941-05-23
Abstract: 549,535. Statistical apparatus. BRITISH TABULATING MACHINE CO., Ltd. May 23, 1941, No. 6655. Convention date, May 24, 1940. Addition to 547,437, [Group XX]. [Class 106 (i)] [Also in Group XX] In the apparatus forming the subject of the parent Specification, in which rows of characters representing data on record cards are recorded on film by photographing characters arranged in sets disposed in parallel lines or columns round a drum 400 which is rotated in timed relation with the cycle of the machine in which the cards are analysed, each row being formed by one character from each column on the drum, and the characters being selected for recording by shutters operated by impulses timed from the record card, the drum bears additional marks 402a each in line with one column of characters, and means are provided for controlling the shutters to photograph a number of these marks simultaneously in a line across the film, the code value of each mark being denoted by its position in this line. Fig. 5 shows a portion of a film record comprising listed items obtained from grouped record cards, the group numbers being represented by these code marks preceding each group, and in digits to the left of the items listed from the first card in each group. Thus the number 762 of the first group is represented in code by the lateral positions of the marks 402<SP>1</SP>a7, 402<SP>1</SP>a6, 402<SP>1</SP>a2 respectively, and in digits to the left of the first items listed. In addition, supplementary marks 420b, 420c may be provided on the drum and photographed on the film as control spots 402<SP>1</SP>b and 402<SP>1</SP>C which respectively indicate the beginning and end of a group and are in line with the group code marks and the group totals. The code and supplementary marks recorded on the film serve to control through photo-electric cells means which stop the film at any desired point in a viewing apparatus of the kind described in Specification 497,054, [Group XL]. Fig. 2 shows diagrammatically the main mechanical elements of a known "Hollerith" (Registered Trade Mark) accounting machine provided with additional means for controlling the photographic recording attachment and operating electrically. A main shaft 44 is driven from a clutch shaft 6 on energization of a main clutch magnet 117, gears 67a on the main shaft driving through further gears the clutch shafts 53 of three accumulators. A gear 44a on the end of the shaft drives through gears 44b, c a shaft 19 which makes one revolution for each machine cycle, and which drives a gear 83 freely rotatable on a reset and totalling shaft 75. Energization of a total and re-set magnet 81 causes a dog clutch to clutch the gear 83 to a gear 74 fast on the shaft 75, which is then driven from the shaft 19 at a two to one reduction of speed. The gear 74 provides the drive to the usual main reset shaft 72 from which the index wheel shaft 69 of each accumulator unit is driven to reset the accumulators. The drum 400 of the recording apparatus is geared to the shaft 19 so as to make one revolution to three of the shaft, there being three sets of characters and code-marks around its periphery. The brushes of four impulse emitters EM 1-4 are mounted on a shaft 85 driven from the shaft 19 but at half its speed, but during each half revolution of the shaft 85, i.e. one machine cycle, one of the two brushes of each emitter wipes over all the segment spots whilst the other wipes over the common segment. The card feed mechanism is driven through gearing from the shaft 6 on energization of a clutch 18. The electric circuits, controlling the machine are controlled by switches actuated by cams L on the continuously rotating shaft 19, cams P on a shaft 92 driven from the shaft 75 and making one revolution during a total taking cycle, and cams (not shown) driven from the card-feeding mechanism and therefore operating only during card-feeding cycles. Each card passes successively through two sensing stations, in the first of which the group number indications are read whilst in the second they are re-read and the listed items are also read. As the units, tens and hundreds brushes at the first station sense the group number indications, circuits are completed through the corresponding segments of the emitters EM 2 , EM 3 , EM, respectively which cause the closure of corresponding relay-operated switches provided with holding circuits, thus retaining a circuit "set-up" corresponding to the group number of the card. Should this number differ from that of the preceding card, which is simultaneously being sensed in the second station, thus indicating a group change, a circuit is broken which in a manner known in this type of machine deenergizes the magnet 18 to interrupt the card feed at the end of the cycle and energizes the re-set magnet 81. During the first half of the reset cycle, the total standing in the accumulator is recorded on the film, the shutter-operating magnets being connected into circuits including the read out commutator and the impulseemitter EM,. Thus, if the digit "4" is in any order of the commutator, the emitter completes the circuit to the shutter magnet of this order at the moment the drum 400 is in the position for the digit 4 to be recorded. During this half cycle the control spot 402c<SP>1</SP> is also recorded at the side of the total by energization of the corresponding shutter magnet. During the second half cycle the film is then fed through two line spacings by a double energization of a magnet operating the feeding means, the accumulators are re-set, and the new group number still retained in the set-up of the switches closed by the action of the emitters EM2, 3, 4 is recorded in the form of control spots 402<SP>1</SP>a, for which purpose circuits are completed through these switches to the corresponding shutter magnets when the line of control marks 402a on the drum is in exposure position. Simultaneously the control spot 402<SP>1</SP>b is recorded by energization of the corresponding shutter magnet. Finally, the film-feed magnet is energized to feed the film through one line space, completing the operations in the re-set cycle. The card feed is now resumed, and the shutter magnets are connected into circuits including the brushes in the second sensing station, which sense both the group number and the list indications on the first card of the new group and complete the circuits of the corresponding shutter magnets in timed relation with the rotation of the drum 400, so that the corresponding digits are recorded on the film. The feeding of cards continue until the next group change, together with the recording of the list items sensed in the second station, the film being fed one line space between each recording operation, but the group control number is not again recorded owing to the opening of contacts in the circuits between the group reading brushes of the second sensing station and the corresponding shutter magnets. The holding circuits of the group-number retaining relays controlled by the emitters EM2, 3, 4 are opened and the groupnumber set-up is re-made as each card passes through the first sensing station. When the first card of a new group is sensed, however, the holding-circuits remain closed to retain the setup of the group number until it has been recorded during the re-set cycle, as above described. Zero suppression circuits are provided to prevent the recording of zeros before the first significant digits. These circuits include contacts in the energizing circuit of each of the shutter-magnets, which are opened by the energization of corresponding relays. The relays are connected in parallel for simultaneous energization, but when any shutter magnet is energized during recording of the digits 9 to 1 it unlatches contacts to interrupt the relay-energizing circuit at a point such that the relay controlling its own circuit and all those controlling the shutter magnet circuits for the digits of lower orders are disconnected. Between the "one" and " zero " recording periods of the cycle the relay circuit is energized, thereby causing all the relays which control circuits for recording higher orders than the highest in which a digit has already been recorded to open the circuits of their corresponding shutter magnets, thereby preventing the recording of zero in these positions. Since, however, the relays associated with the circuits for recording digits of the lower orders are disconnected, the recording of zeros to the right of the first significant digit is not prevented. Specification 429,950 also is referred to.