Patent GB-934435-A (GB)
Title: Improvements in or relating to photo-type composing machines
Inventor: BRAGG CECIL
IPC: B41B17/06
Filed: 1959-03-13
Abstract: 934,435. Photographic type-composing apparatus. MONOTYPE CORPORATION Ltd. March 11, 1960 [March 13, 1959], No. 8798/59. Class 98 (1). In a photo-type composing machine in which master characters carried by a rotatable disc are brought one by one as required into the projection position and is light-sensitive surface is exposed to the projected image with relative movement of that surface and the projection position between exposures to effect spacing of characters along a line of composition, the master characters are disposed circumferentially on two or more discs rotatable about a common centre and means are provided for positioning any one of the discs in a projection plane conjugate with the light-sensitive surface, the disc so positioned being connectable to means for rotating it to effect character selection while the other disc or discs are locked in positions in which apertures in them are in line with the projection position. As shown, discs 1, 2, 3 bearing characters, typically in italic, roman and bold founts respectively are freely rotatable on a hub 4 slidable along a spindle 5 and are controlled by a character selection disc 16 and a fount selection handle 11. To select a chosen fount, the disc 16 is set to a change fount position when the disc apertures 13 are aligned adjacent a locking bar 19 which engages in a lower of the two tooth gaps 15 in each disc. By then moving the handle 11 into the appropriate slot 1a 2a, 3a of the gate 12 arm 6 slidably carried by splined shaft 7 moves the hub 4 to position the chosen disc in the projection plane with its teeth 14 opposite a gap 19a in the locking bar 19 and the upper gap 15 in engagement with an arm 17 attached to the disc 16. The disc 16 is then rotated to select a chosen character by " dialling " it by inserting a finger in the adjacent internal serration 16c on the disc 16 and rotating it until contact is made with a trip member 106. Operation of this causes mechanical locking of the disc 16 by a lever not shown, movement of locating members 31, 32 on one of the arms 27 defining a gap 26 to clamp the chosen master character 20 against the other arm 27, the block 28 being positioned so that the disc passes between the arms while when changing discs the arms pass through the disc apertures 13, and lighting of the lamp C to projection print via lens D the character on a light-sensitive sheet on a film carrier E. Each master character is accompanied by a four bit binary code pattern 35, none, one or more of which bits may be transparent, representing an excess of 0 to 15 units over a minimum space of 5 units so that the lamp C energizes the corresponding one of four photo-electric cells which operate in a mechanism J one or more shafts 82 ... 85 having cut-away parts positioning vertically a particular stop plate 80 limiting movement of a feeler rod 79 which controls lateral spacing movement of a carriage F on which the film carriage E is mounted. The duration of the exposure is controlled by a timer A set by a manual control 110 and at the end of the exposure the lamp is extinguished and rotary solenoid 69 is energized to rotate shaft 68 anticlockwise and by cam 64 rock discs 62 anticlockwise to move a rack 54 into engagement with a toothed wheel 49 and to release the pawl 55 locking the wheel. Rotation of shaft 68 causes closing of contacts 71, thus energizing constant stroke rotary solenoid 70 whereby link 76 first pivots about pin-and-slot joint 77 until feeler rod engages the previously positioned stop plate 80 in the unit J and then pivots at 75 to cause the rack 54 to move to the right to drive the wheel 49 and so via gear-box 50 ... 53 drive shaft 46 to rotate drum 40 via clutch 47 and sleeve 45 to wind up the tape 41 which moves the carriage F. At the end of the energized movement of solenoid 70, normally closed switches 108 are opened by arm 109 and open the circuit to solenoid 69 which then returns under spring action to its original position, opening switch 71, re-latching wheel 49 and disengaging the rack 54. A dashpot 70a controls the return movement of the solenoid 70 and the idle return of the rack 54. At the end of a line, the shaft 46 rotates clockwise until a peg 43 on the drum 40 engages a stop 44 so that the carriage F returns to a fixed zero position, and interline spacing is effected by a mechanism G. To provide for composition in different point zones the positions of the lens D and film carriage E relative to the master character disc in use are varied and the corresponding along-the-line travel of the carriage F is provided by altering the unit of tape feed. To this end, when the shaft 46 is rotated under control of the mechanism J, a slide 97 driven by gears 99, 98 (Fig. 6) from the shaft and connected to one end of a lever 93 rotates the lever about a fulcrum on an adjustable block 94, the opposite end of the lever being connected to a link 91 bearing the shaft of a tape pulley 88. Except when the fulcrum of the lever is aligned with the pivot pin of the link 91, the roller 88 is translated in proportion to the rotation of the shaft 46 representing the character width on a unit basis and the lever ratio representing a factor related to the point zone magnification of the lens so that the total movement of the carriage F is equal to the space occupied by a selected character of chosen point size. If variation of point size is made during a line, the carriage drive must be disconnected before adjustment of the fulcrum block 94, the tape 41 meanwhile being held by a clamp 141. For indenting or producing justified lines, a knob 102 is provided for effecting additional movement of the carriage F by moving the tape pulley 89. Interword spaces and additional spaces in a line are obtained by setting the desired space value on a dial 103 and depressing the space bar 105 which controls circuits which by-pass the character binary code signals, prevent the character exposure means from operating, and permit operation of the mechanism J and the carriage feed mechanism to cause the required movement of the carriage.