Patent GB-551455-A (GB)
Title: Improvements in or relating to photographic copying apparatus
IPC: G03B27/50
Filed: 1942-08-26
Abstract: 551,455. Photographic copying-apparatus. KODAK, Ltd. Aug. 26, 1942, No. 12036. Convention date, Nov. 26, 1946. [Class 98 (i)] A photographic copying-apparatus comprises associated projecting and scanning means which are given the same angular movement so that successive portions of a document positioned on an arcuate support are projected on to sensitive material carried by a second arcuate support. The apparatus shown comprises a casing at the front of which is an arcuate transparent plate 20 on which the document is held by a platen 21. The sensitive material passes from a roll 28, between pressure and feed rollers 68, 69, to arcuate supporting ledges 30 at the sides of the exposure field. The mount 42 of the projecting lens is rotatably mounted in a bearing formed in a bracket 39 at the foot of a partition 17 extending across the casing. Secured to the mount 42 by connecting members 45 is a light-restricting scanning member 44, extending towards the transparent plate 20 and carrying lamps 47 and reflectors 48, 49 for illuminating the.document. During exposure the lens and scanning member have a clockwise angular movement from the position shown in Fig. 4, the end of the scanning member passing over the document from top to bottom. The image on the sensitive material is formed by reflection from a mirror 51 so avoiding lateral inversion of the image. A shaft (not shown) extends from one end of the lens mount into a housing 112, Fig. 6, where it carries a gear connected to a train controlled by an adjustable governor which controls the speed of the scanning movement, which is caused by a helical spring surrounding the shaft. The apparatus is operated by an arm 54 secured to a shaft 56 carrying a disc 60. To this disc is attached an arm 61 at the end of which is a pawl 63 adapted to engage an endless sprocket chain 71 which drives the 'feed-roll 69. During the downward stroke of the arm 54 the arm 61 rises, and the pawl moves the sprocket chain over an arcuate guide member 74, causing the sensitive material to be fed. Towards the end of this movement the pawl is disengaged from the chain by a cam surface 79 which engages a pin 76 on it. During the return movement of the arm, the pawl slips over the chain. When an exposure has been made the platen 21 is swung open, so rotating a shaft 23 to which it is secured and causing an arm 124, Fig. 6, on the shaft to operate through a lever 121 a pawl which then retains the gear train 112 to prevent further operation of the scanning means until the platen is again closed. A second arm 100 on the shaft 23 simultaneously moves to allow an arm 96 to move towards the right, Figs. 4, 7, 8, so turning a release member 92 to which it is connected in an anticlockwise direction, whereby a lug 93 on the member 92 rides off a cam surface 102 on the face of the journal 57. The member 92 bears on the tail of a U-section member 85 pivoted at 86 on the arm 61, and carrying a stud 87. After a new document has been placed on the platen, the arm 54 is given a downward stroke, causing the sensitized material to be fed as above described, and towards the end of this stroke the stud 87 on the member 85 snaps past a co-acting stud 83 on an arm 82 secured to a shaft 81 extending from the lens mount, the arm 82 being at this time in the position shown in broken lines in Fig. 4. The arms 61, 82 are thus latched together, so that on the return stroke of the arm 54 they move down together to the positions shown in full lines in Fig. 4, returning the lens and scanning-member 44 to starting position for a fresh exposure. On closing the platen 21 the shaft 23 is rocked, causing the release member 92 to turn clockwise, move axially. on the shaft 81 owing to the inclines 92, 93, and so turn the member 85 on its pivot 86, thus releasing the stud 87 from the stud 83. Simultaneously, the pawl holding the gear train 112 is rendered inoperative, and the lens and scanning device move to make the exposure. A mercury switch 103 is rocked to open the circuit of the lamps 47 by a pin 107 on the arm 96 when the platen 21 is open, and also at the end of an exposure by the engagement of the scanning member 44 with an arm 163. The length of sensitive material which has been exposed is indicated by a marginal perforation made by the pointed nose 147 of a rod 146 which is moved by the engagement of a pin 150 on the disc with a cam surface 149, Fig. 7. The exposed material passes out through a slot 156, and may be wound on a roller in a detachable casing 154, driven by a belt from a pulley on the shaft of the sprocket 73.