Patent GB-719376-A (GB)
Title: Improvements in or relating to composing apparatus for reproducing typographical andlike matter by photographic means
IPC: B41B17/04
Filed: 1950-07-20
Abstract: 719,376. Photographic type-composing. CLOWES & SONS, Ltd., W., and CROUCHER, H. G. July 13, 1951 [July 20, 1950], No. 18120/50. Class 98(1) The machine comprises a support for an element or elements bearing characters to be photographically reproduced, means for supporting a lightsensitive receiving surface, an optical system for projecting images of the characters on the surface, the support, receiving surface supporting means and optical system being capable of relative movement perpendicular to the projection axis so that images of selected individual characters can be projected on the surface for reproduction, mechanism controlled by previously prepared record-bearing means for effecting such relative movements in succession to reproduce the characters in spaced and justified lines, the relative distances in a direction parallel to the projection axis between the optical system, the plane of the character to be reproduced and the receiving surface plane being adjustable, means for maintaining during such adjustment the required varying proportions between the adjusted distances so as to vary the size of a reproduced character and to focus the image thereof correctly upon the receiving surface, and means controlled by record-bearing means either comprised in or driven in synchronism with the aforesaid mechanism for adjusting the distances to enable the size of each reproduced character to be varied. Character-projection system. As shown in Fig. 3, the machine has a lighttight cover 9. A mounting tube 33 carrying a lamp 32 and a condenser 36 is slidable in the cover by means of a pair of supporting levers 38 pivoted 43 to a bracket 2b on the frame of the machine. A pair of levers 39, pivoted to bracket 26 at 42 and connected to levers 38 by a link 37, are connected to a lens mounting 77 slidable in a guide 79. A member-75 pivoted to a lever 39, engages a wedge 74, which is moved by a rod 73 connected to control mechanism when the size of image is to be changed to move the light source and the lens 77a together. A shutter 80 is mounted in front of lens 77a to make exposures. To prevent overheating, a shutter 52 may be mounted in front of condenser 36 and opened just before, and closed just after, the shutter 80. An iris diaphragm 54 is mounted below shutter 52, and is actuated by a stud 55 engaging a cam slot 56 in a fixed tube so that as the degree of enlargement is varied, the intensity of the light is also varied to keep the required exposure time constant. A plate carrying the characters for projection is mounted in a case 62 in a frame 61, which is grooved to move along a frame 60 in one direction, the frame 60 being movable in the perpendicular direction. Case 62 can thus be positioned, by mechanisms not shown but similar to those used in machines of the kind known under the Registered Trade Mark " Monotype" in two directions at right angles, to bring a selected character into position for projection. Case 62 has pairs of depending lugs 66 sliding on rods 67, connected by cross rods 68 to pairs of elements 69 which rest on pairs of wedges 70. These wedges, or, according to the Provisional Specification, rotatable cams, are movable by means of the control mechanism to move the case 62 vertically. Thus the lens 77a and the case 62 are movable to focus images of different sizes on the photographic film, supported on a plate 83 of a movable table 82 of the kind described in Specification 706,312 [Group XVI], the movements of the table being such that successive projected characters form lines of type. The line-shift mechanism is modified slightly to provide different inter-line spacings. This is in addition to the variation of spacing according to character size, described below. In an alternative form, the lamphouse and lens are threaded, and are movable by means of surrounding nuts which are prevented from moving axially, but which are rotated by racks movable by the control mechanism. The same objects may be achieved by moving the sensitized surface while the character-bearing plate remains in the same plane; two further modifications for carrying out these movements are described. Character carrier Positive or negative normal or reversed characters may be carried by a transparent sheet, but preferably the characters are provided on separate blocks, e.g. of glass, bearing the character and set in a stainless steel frame. The blocks are assembled in a frame and held between transparent or perforated metal plates. When the apparatus is used in conjunction with photogravure and like processes, line screens may be used together with the character transparencies. Film perforating and winding mechanism The sensitized surface may be e.g. a photographic plate or cut film, but is preferably film wound on rollers 89, 89a. In some circumstances such film has to be perforated, and this is done by punches 115, Fig. 9, sliding through the casing of a film container 4 which rests on plate 83. The winding spool 89 engages a pin 133a on a driving disc 132a journaled in a wall 85a of the casing 4, which wall may, if desired, be adjustably positioned in the casing in accordance with the width of film. Disc 132a is splined on a shaft 130a journaled in brackets 856, 85c, and connected by a one-way drive to a pinion 136a meshing with a fixed rack 137. The film is not wound during the line-by-line movement in reproduction, but when a page is completed, the return movement causes the film to be wound to provide a fresh surface for the next page. The film may also be wound manually, by means of a tool or by means of a differential gear, if the length of film to be wound is greater than a page. Line-by-line movements are effected by mechanism described in Specification 706,312, [Group XVI]. The stroke of a part actuated by this mechanism is limited by a block placed between this part and a fixed part of the machine. By using a number of blocks of different sizes brought selectively into position, the distance between lines of text can be varied. Means are described for stopping the machine when the film is exhausted by means of a lever system, or, according to the Provisional Specification, by means of a steel tape or counting mechanism as described in Specification 719,372, [Group XVI], Removal and replacement of film container. The film container 4 is removed from or replaced on the plate 83 through a door 103, Fig. 14. On insertion of the container 4 into guides 84, a flange 170 on the sliding lid 88 of the container engages a groove in a bracket 172 mounted on a slide 160 mounted in the 'frame of the machine. This slide is normally urged to the right by a spring, but when the door is closed, it is moved to the left by a handle 160a which is then held by a catch. Lugs 174, 174a, 174b on the slide engage lugs 175, 175a, 175b on the door to keep it closed, and by means of bracket 172 lid 88 is slid to uncover enough film for the printing of the first line. As composition of lines proceeds the container 4 moves to the right, exposing more film as required. When the container is first inserted, a cam surface 178 thereon engages a pin 179, which is linked to a lever 182, which is thereby held up so that when door 103 is closed, a lug 184 on slide 160 passes thereunder. When container 4 starts to move when composition begins, surface 178 moves away from pin 179 and lever 182 drops so that a recess 183 therein engages lug 184. The door cannot then be opened until the container 4 is brought back to its initial position. A rack 102 on slide 160 engages a pinion 98. When the door is opened, the movement of the slide rotates the pinion, which actuates mechanism which raises the objective lens to prevent damage when the container is removed or replaced. Control mechanism. This mechanism, shown in Fig. 17, is similar to that described in Specification 719,371, and is controlled by a record strip prepared by keyboard means as described in Specification 719,372, [Group XVI]. A cylinder block 1090 has four pistons (of which only three are shown) actuated by different compressed air supplies. Each piston has a stop in a different place, so that a base plate 1091 on a rack 156x is moved through a different distance according to which air supply is used. A pawl 158x engages ratchet teeth on the back of rack 156x to prevent its return movement; this pawl can be released by actuating either a compressed air piston M5x or a rod 508c. The rack engages a gear wheel 1061 splined to a shaft 1060 carrying a disc 1050 on which four gauge rods are mounted. These rods control the setting of the optical system for different sizes of projected characters. A lever 1000 is rocked continuously by a cam on the main shaft of the apparatus, and is connected to mechanism which, when actuated, connects it to a slidable rod 1002 for two strokes. Rod 1002 is connected to a cross-head 1004, slidable on the shaft 1060 and on a shaft 1052 splined to a pinion 1053 engaging rack 156x, and urged to the right by a spring 1002a. Shaft 1052 and pinion 1053 are connected to mechanism (not shown) of the kind described in Specification 779,374, [Group XVI], for justification of the characters. Shafts 1052, 1060 are connected respectively to longitudinally slidable bars 1014, 1013, so as to move longitudinally with the bars but to rotate freely with respect to them. When cross-head 1004 is moved to the left, a buffer 1007 thereon engages one of the gauge rods on disc 1050, thereby moving shaft 1060 through a distance depending on which rod is brought into position by movement of rack 156x. This causes movement of bar 1013, which is connected to the rod 73 controlling the setting of the projection lens. Bar 1013 is held in place by a spring-urged wedge 1200. When character size is to be changed, lever 1000 is engaged to move the cross-head 1004, and a rod 1127 is raised by a compressed air piston, thus bri