Patent GB-499859-A (GB)
Title: Improvements relating to methods and apparatus for photographically composing text-matter
IPC: B41B17/06
Filed: 1937-04-27
Abstract: 499,859. Photographic type-composing. WESTOVER, G. April 27, 1937, No. 12022. [Class 98 (i)] Text matter is photographically composed in justified lines by assembling single characters on a movable transparent master plate, which is positioned under the control of a record strip to position single characters in desired succession, projecting each character separately on to a sensitized line strip, and advancing the line strip under the control of the record strip to produce interword spaces to justify the projected line. An arc lamp projects light horizontally through a shutter 4, comprising a series of slats 5 movable by a rod 7, to a reflector 15, and thence through a tube 13 which is given a vertical reciprocating movement to bring a sliding tube 14 over the selected character on the master plate 45, Fig. 4, in a frame 44. The tube 13 comprises two parts 13a, 13b, pressed downward by a spring 19. The part 13b carries a sleeve 21 with a cup-shaped member 22 terminating in the tube 14. A lever 26, Fig. 15, is connected by a link 27 to an operating lever 23, and surrounds a sleeve 29 mounted on the tube 13a. The other end of the lever 26 is pivoted to a fixed post 30. On the downward movement of the lever 26 a resilient pressure is applied through spring 33 to a crosshead 34 connecting two sliding pillars 35, 36 on the fixed support 31. The main actuating lever 28 is pivoted on the part 13b so as to apply a resilient downward pressure through spring 19 to the tube 14. The lever 28 carries a projection 28a coacting with tappet 28b on a crank arm carried by a crossshaft 39, which, through another crank with tappet 40b, actuates the shutter 4. A frame 41 supports within it a frame 42 carrying the negative holder 43 within which is a sub-frame 44. In operation, the lever 28 first lowers the frame 41 to a position in which the sub-frame 44 is located to bring the selected character in line with the tube 14, and then applies a resilient downward pressure to lower the tube 13 till the tube 14 encloses the character to be projected, finally opening the shutter 4 to project light through the plate 45 to the film. The plate 45 is a negative bearing the characters in 15 rows, each row containing 15 characters. The underface of the sub-frame 44 is provided with two series of rack teeth 50 at rightangles, adapted to engage with two bars 51 at right-angles, by which the sub-frame is accurately positioned with respect to the lens 59 below, Fig. 10. To enable the sub-frame 44 to be removed, a member 52, Fig. 4, is provided at one end of the frame 43 held in place by spring-pressed pins 53. The subframe 44 is loosely held in frame 43, the clearance permitting lateral adjustment by the rack bars 51, which are provided with a fine differential screw adjustment with respect to the fitting 56, Fig. 10. The lens 59 is mounted in an adjustable bushing 58 above a sleeve 60 surrounding a tube 61 which receives a projecting part 62 above the film spool magazine. The film spools carry the usual 16 mm. film which passes over a pair of geared feed drums so that the part to be photographed passes across the axis of the tubular member 62 which projects upward from the magazine. If in photogravure work a separate screen is employed for the text, such screen may be embodied in the character drawings and photographed directly on to the film, or a screen may be arranged adjacent to the film. The shaft of the supply spool has a friction brake to prevent excess unwinding. The intermittent drive mechanism for the sensitized film comprises a lever 82, 83, Fig. 23, pivoted at the ends to bars 84, 85, the bar 85 being connected at 87, 88 to cranks which drive the feed drums over which the film passes. The bar 84 is guided, Fig. 10, so that it moves longitudinally, and a hole 86 in the bar allows the passage of light between the plate 45 and the lens 59. The bar 84 is reciprocated by cam mechanism from the main driving shaft, its amplitude of movement being varied by an adjustable stop in accordance with the width of each character projected and the justification space under the control of the record strip. A movable wedge mechanism such as that described in Specification 8633/99, [Class 100], may be used. In order that the bar 85 may drive the drums 66, 67 in one direction only, the cranks 87, 88 are free to rotate on their shafts but are keyed thereto on the forward stroke by the energization of solenoids 90, Fig. 26, which attract a flanged disc 89. On the return stroke, solenoids 91. hold the disc 89 stationary. To vary the spacing of the characters, the relative lengths 82, 83 of the lever are varied by moving the fulcrum 82a. The lever is held in a sleeve 96 carrying a forked support 97 sliding in a guide under the control of pivoted members 103, 104 moved by a screw 106. In a inodification, Fig. 28, not shown, the movement of the bar 84 may be transmitted to the bar 85 in any desired ratio by means of a hydraulic system. The margins at the beginning and end of each line are fed by mechanism inde pendent of the film feed to avoid cmnulative errors. This mechanism comprises a shaft 92f driven by worm gearing from the main shaft, carrying a ratchet 92g, Fig. 3. Between adjacent lines of the text, the record strip trips a lever 92i to release a pawl 92j carried by a disc 92h loose on the shaft, which is then rotated by the cam 92g. The disc carries contacts which are closed when it is stationary and opened when it is rotated. The disc 92b carries a pair of cams 114, 115, Fig. 32, on its underside, arranged at 180‹, which, through linkage 116, operate a pawl 117 engaging a ratchet wheel 118 making one revolution per line, and which drive the feed drums. One cam feeds a margin at the end of a line, and the other at the beginning of the next line. To provide facilities for kerning, the tube 14 which confines the light may be provided with a hole of the desired contour. Specification 17199/08, [Class 100], also is referred to.