Patent GB-818786-A (GB)
Title: Photographic reproducing machine
IPC: G03B27/50
Filed: 1957-05-08
Abstract: 818,786. Photographic type-composing. MERGENTHALER LINOTYPE CO. May 8, 1957 [Aug. 2, 1956], No. 14645/57. Class 98(1) A photographic reproducing machine includes a holder for an input strip with images to be reproduced spaced along it, means for positioning the strip with one of its images at the photographic station, an optical system including a fixed lens for projecting the image on to an output strip of photographic material, a mirror normally positioned in the projection path between the lens and the output strip for projecting an image on to a viewing screen and means for moving the mirror out of the projection path when the output strip is to be exposed. As shown in Figs. 1 and 5, a strip of film or paper 1 bearing lines of type 2 has sprocket holes 3 engaging sprocket 6 on a shaft 7, whereby it may be fed between guide plates 4, 5 mounted on a frame member 9 on carriage 8 either manually, by means of a knob 18 on shaft 7, or automatically by means of a rotary solenoid 21. A detent wheel 10, having a number of dwells engaged by a spring-urged roller, holds the strip 1 in position with a line 2 registering with apertures 16, 17 in plates 4, 5. The strip 1 is illuminated from behind by a tubular lamp 26 when transparent or by lamps 27 from in front when opaque. Light from the strip is reflected by a mirror 28 and a pair of mirrors 29 to a lens 30. A shutter 31, close to the lens, consists of a pair of blades pivoted scissors-fashion and operated by a roller mounted on the arm of a rotary solenoid 35. Light passing through the lens and shutter is reflected by a pair of mirrors 37 to a strip 38 of photographic material, which is unwound from a roll in a removable light-tight housing 39 and moved across a platen 40 by rollers and is fed to a cylindrical chamber 41. Knives are provided to sever the portion of exposed strip in the chamber 41. A spring-loaded arm carrying a roller held in contact with the feed roll 38 operates switches 195, 197, Fig. 31, to light lamps 196, 198 when the roll is nearly exhausted and exhausted respectively. Variation of magnification. The mirrors 29 are mounted on a carriage 44 movable by means of rollers 45, 47 on a pair of vertical rails 46 (see also Fig. 3). A pair of levers 48, 49 are both connected to a sleeve which is freely mounted on a shaft 51. Lever 49 is in engagement with carriage 44 to move it along the rails, while lever 48 is in contact with a roller 52 mounted at the end of a lever 53 pivoted to a bracket 54, and carrying a roller 55 which bears on the edge of a cam 56. The shaft 57 of cam 56 is driven through worm gear by a hand wheel 62 on a shaft 61. The mirrors 37 are mounted on a carriage 63 also movable along the rails 46, connected to endless bands 65 passing over idler pulleys 66 and pulleys 67 mounted on shaft 57. Thus, rotation of hand wheel 62 moves both pairs of mirrors 29, 37 to vary the optical path and to alter the magnification of the image. The line of type at the aperture 16, 17 is so arranged that a line touching the tops of the upper case characters intersects the optical axis; the image formed on the strip 38 will be similarly aligned. The point size is indicated by a pointer 69 on a vertical scale 68, and a scale on the hand wheel 62 is graduated in fractions of a point. The time of exposure is adjusted according to the magnification by means of a cam 70, mounted on a shaft 57, which engages a roller 71 on a pivoted lever 72. The free end of lever 72 is pivoted to a link 73 having a pin-and-slot connection 74 with a bell crank 76 which carries a toothed sector 78 engaging a gear 78 for adjusting the setting of an exposure timer 79. The pin-andslot connection 74 allows adjustment for the effect of emulsion speed of the photographic strip 38. Means operated by another cam on shaft 57 adjust the distance through which the strip 38 is advanced by the main crankshaft of the machine after projection of each line in accordance with the size of the projected image. and provision is made to increase or decrease this movement of the strip by a small amount independently of the image size. An image of the projected line is formed on a screen 111 by a mirror 109. Means operated by the main crankshaft move the mirror 109 from a position in the light beam for viewing the image to a position clear of the light beam for printing. A shutted 110 (not shown), also operated by the main crankshaft covers the screen 111 during printing. Operating sequence. The main cam shaft 20 (Fig. 31) is driven by a continuously running motor through a slipping clutch (not shown). Initially, the cam shaft is held stationary by a pin 144 engaged in a hole 145 in part of the clutch. When a switch 147 is closed, a circuit is completed through a switch 149 and a solenoid 150, which pulls pin 144 clear of the hole. When the camshaft 20 begins to turn, a cam 148 opens the switch 149, so that solenoid 150 is re-energized and pin 144 bears, by spring action, on the periphery of the clutch member. A cam 151 then closes a switch 152 to energize solenoid 35 which closes the normally open shutter 31. At the same time the shutter 110 in front of the viewing screen is closed by cam 125 and the mirror 109 is moved out of the light beam by a cam 139. The energizing circuit of solenoid 35 is then broken, so that shutter 31 opens to expose the strip 38, and at the same instant a cam 153 closes a switch 154 to set the timer 79. At this point, the pin 144 engages a second hole 155 in the clutch member, and camshaft 20 is halted until, near the end of the exposure time set, a timer switch 156 closes and completes a circuit energizing solenoid 150, which pulls pin 144 clear of the hole. Switch 156 opens again as the shaft begins to rotate again, the energizing circuit of solenoid 35 is opened and the shutter 31 closes, and a cam 19 closes a switch 157 to energize solenoid 21, actuating mechanism which advances strip 1 to bring the next line of type to the position for projection, and to advance the strip 38 and a translucent paper sheet 241 (see below). Near the end of the rotation of camshaft 20, cam 139 moves mirror 109 back into the path of the image forming beam, solenoid 35 is energized to open the shutter 31, and cam 125 reopens the shutter 110 before the screen 111, on which the image of the new line of type is displayed. Pin 144 then snaps back into the hole 145, stopping the cam-shaft. In order that several lines may be printed automatically in sequence, a Geneva wheel with one wide notch and several narrow notches is set back by a number of notches equal to the number of lines to be printed. The wheel is fast with a cam which closes contacts 168, energizing a solenoid 170 to keep the switch 147 closed so that camshaft rotates continuously, until a pin mounted off centre on a disc on camshaft 20 turns the Geneva wheel, engaging one slot at a time, until the large slot is reached. At this point the cam opens contacts 168, and the camshaft stops. Means are also provided whereby the advance of the strip 38 after exposure is omitted, for use e.g. when the text is to be arranged in double column form. Adjustment of original strip. The frame 9 of the carriage 8 for the strip 1 carrying the text has upper and lower rails 213, 209 resting on rollers 214, 210, Fig. 5. mounted in bell-crank levers 215, 211 pivoted to cross members 216, 212 carried by the main frame. Lever 215 is loaded by a spring 215a, and levers 211 are pivoted to an actuating member 218. The frame 9 can thus be moved up and down by rotation of a cam 219, against which member 218 bears, by means of a shaft 220 extending to a knob on the front of the machine. The cross members 216, 212 are connected by a bridge member 222 (see also Fig. 6), and a rack 224 is slidable in grooves in the lower member 212 and also in a ledge 223 formed on the bridge member 222. A plunger 225 carrying a knob 226 is slidable in rack 224, and carries a pin 227 engaging a vertical slot in rail 209. Thus rotation of a pinion which meshes with the rack which is connected to a knob on the front of the machine moves the frame 9 sideways. A dial geared to the operating knob indicates the extent of the sideways shift. The possibility of a tilting movement of carriage 8 is indicated. To move carriage 8 to change the text bearing strip 1. pin 227 is withdrawn from the slot in rail 209. The carriage can then be pulled sideways, additional support being given by rollers 238 mounted on the cross members 216, 212. The strip 1 may be advanced without otherwise operating the machine by means of a switch 239 (Fig. 31), which actuates the solenoid 21. Another switch 240 prevents the advance of the strip while the machine operates. Make-up sheet. A sheet of translucent paper 241 (Fig. 1) is fed from a roller in the bottom of the machine past the viewing screen 111 to a take-up roller at the top of the machine. As shown in Fig. 14, the sheet is fed between feed rollers 244, 247 at the top of the machine. The shaft 245 of roller 244 is journalled to the side frames. while shaft 248 roller 247 is journalled in arm 249 pivoted to the side frames. A wide gear 246, Fig. 15, is mounted on shaft 245 and meshes with narrow gears 250, 253 mounted respectively on shaft 248 and a stud 254 journalled in a depending arm 255 adjustably mounted on a fixed stud 256. Gear 250 is maintained in mesh with gear 246 by action of spring 251, and gear 253 is driven by a chain-and-sprocket drive from the drive shaft for strip 38. The chain tension can be adjusted by rotating arm 255 about stud 256, which is in line with shaft 245. The sheet 241 may be prepared as a chart to guide the operator in make-up of the text, or, it may be blank and used to mark off the space occupied by each projected line. Specification 801,481 is referred to.