Patent GB-1195744-A (GB)
Title: Calculation and Display of Justification Information
IPC: B41J19/64
Filed: 1967-08-10
Abstract: 1,195,744. Typewriters &c. INTERNATIONAL BUSINESS MACHINES CORP. 10 Aug., 1967 [19 Sept., 1966], No. 36753/67. Heading B6F. [Also in Division G4B] A device for use in justifying a trial line printed by a typewriter comprises an axially movable cylinder 52 with a slot 51 calibrated at 50 in units of spacing and a second cylinder 41 within the first cylinder and rotated one step at each operation of a space-bar 14, Fig. 3, for word spacing. The cylinder 41 has a chart 42, Fig. 4, comprising horizontal lines N1, N2, &c. which are aligned with the slot 51 after one, two, &c. word-spacing operations, respectively. Each line has differently coloured parts 46 each of a length equal to the unit spacing P of scale 50 multiplied by the number of interword spaces associated with the line. In the machine described, after a type head 12 reaches a predetermined position near the end of a trial line, the cylinder 52 is caused to move axially therewith so that the scale 50 indicates the number of units of spacing between the head and a margin 45, Fig. 4. When the trial line has been completed, the leftward coloured part which is fully exposed by the slot 51 indicates the number of units of spacing to be added to each standard word spacing for approximate justification and by reference to the scale 50 also indicates a smaller number of units remaining which have to be distributed for complete justification. For example, if (1) the standard word spacing is 3 units, (2) 7 word-spacing operations had occurred so that slot 51 is on line N7 as shown, Fig. 4, and (3) the scale 50 indicates that there are 30 units of spacing between the end of the trial line and the margin 45, four units must be added to each word spacing as indicated by the fourth coloured part 46 being completely exposed and one additional unit to two of the word spacings for justification as indicated by the scale 50. As described below, the machine can be set so that during retyping of the line, the first two operations of the space-bar 14 cause word spacings of 3 + 4 + 1 units and the next five operations cause word spacings of 3+4 units. The step-by-step movement of the cylinder 41 is effected by a ratchet-and-pawl mechanism 61, 62, Fig. 2, actuated by a pull-rod 64 when the space-bar 14 is operated. A spring 65 is woundup during this movement, and returns the cylinder 52 to its initial position when a detent pawl 66 is released by operation of the carriagereturn mechanism. The cylinder 52 is fixed to a rack 54, Fig. 2, urged in spacing direction by a spring 71 and normally connected by a pin 72 to a rack 73 forming part of a margin mechanism 70 and having a pawl 74 normally engaging a stationary margin rack 18. Gearing 76, Fig. 5, connects rack 73 to a rack 75 urged in the spacing direction by a spring 75b. When the printing head 12 reaches the preselected justification range, the pawl 74 is released by a lug 22 on the printing head carrier 20 and a pawl 23 on the carriage 20 of the head 12 drops behind a lug 75a on rack 75. During subsequent movement of the head 12, the rack 75 moves with the head 12 and through the gearing 76 transmits to the rack 73 and therefore the rack 54 and cylinder 52 a magnified movement of the head. When carriage return after typing the justified line is effected, the parts 52, 54, 73, 75 are moved back to their initial positions. An escapement pitch selector (15, Fig. 1) is provided on the machine, and a number of slots 51 and charts 42 are provided on the cylinders 41, 52 corresponding to the various pitches. A pitch selector 15 permits the selection of any one of three pitches of escapement. The machine can be set in accordance with the information obtained from the chart 42 so that during typing of a justified line, operation of the space-bar 14 effects the required word spacing. Actuation of the space-bar 14 rotates through an interposer 14a a shaft 30, Fig. 3, carrying a key 32. The key 32 operates on one of a number of links 31 according to the axial position of the key, the links 31 being connected by cables 11b to mechanism controlling the escapement so that a spacing is obtained according to which link 31 is operated. The shaft 30 is moved axially to align the key 32 with the required link 31 by means of a knob 33 connected by gearing to the shaft 30. The knob 33 co-operates with an indicator plate 34 with segments coloured similarly to parts 46 of the chart 46 and, for the example given above, is set to give a spacing of eight units. After two word spacing operations the knob 33 is automatically rotated one step, thus moving the key 32 so that subsequent word-spacings are seven units as required in the example given. For this purpose a settable wheel 37 is rotated to a position indicating "2". When the space-bar 14 is depressed for the first two word-spacing operations, a pawl 38 actuated by the bar engages a pinion 35 to step the wheel 37 to its zero position. In this position a deep tooth 35a in the pinion 35 allows the pawl 38 to move so that it also engages a pinion 33b attached to knob 33, so that the latter is rotated one step to move the key 32 in order that succeeding word spaces are reduced from eight to seven units.