Patent GB-1060572-A (GB)
Title: Apparatus for conveying and separating mutually adhering sheets
IPC: G03B17/52
Filed: 1964-02-10
Abstract: 1,060,572. Sheet separating apparatus. GEVAERT PHOTO-PRODUCTEN N.V. Feb. 10, 1964 [Feb. 11, 1963; Sept. 23, 1963], No. 5533/64. Heading B6H. [Also in Division G2] As two mutually adhering sheets are progressed towards a separating blade, their leading edges are urged apart, so that the blade can enter between them and cause them to be peeled apart as their progression is continued. In the diffusion transfer apparatus shown, the exposed light-sensitive sheet 26 is fed over a guide plate 18 so that its leading edge enters into a slot 22 in a drum 10, where it is held firmly, the slot at that time being opposite guide 18. As the drum rotates, sheet 26 wraps itself round the drum, and it is coated with developing liquid as it passes against a roller 14 which dips into a bath 13 of the liquid. A further roller 15 acts as a squeegee to remove surplus liquid. Just in front of slot 22 the drum has a sloping cam projection 23, which in Fig. 1 is shown as about to pass under the pressure roller 16. The image-receiving or copy sheet 27 is fed from a pile 63 of such sheets and conveyed between guides 19, 20 to the nip between roller 16 and drum 10. The feeding means for sheet 27 is actuated by a cam 62 fixed to the drum, and a microswitch 61, and is timed so that sheet 27 reaches the said nip just before sheet 22. The two sheets then pass together between the pressure roller and the drum, so that the image transfer is effected. The leading edges of the two sheets are, however, at all times slightly separated, since the edge of sheet 27 rests on the slope of cam 23. Continued rotation brings the sheets to a separating blade 17, which is tapered from a maximum central width as shown in Fig. 2. The blade is pivoted so as to rest under light spring-loading against the drum. As cam 23 passes under the blade, it lifts it slightly, so that the blade passes below the edge of sheet 27. Thus as the drum rotates further, sheet 27, which is above the blade, peels away from sheet 26, which is below it. Since sheet 26 remains lying on the drum, any desired number of copies may be made. Fig. 4 shows a modification which may be adapted to existing apparatus. The exposed developed light-sensitive sheet 26 and copy sheet 27 are shown as having already been passed between pressure rollers to effect the image transfer. The leading edge of sheet 26 is in front of the other sheet, and is shown as just passing over a roller 35. The separating blade 41 is lowered, so that its curved bottom edge engages against the leading edge of sheet 26, and deflects it into the path shown by the dotted line. Sheet 27 tends to continue in its original path, and so passes above the blade edge. Sheet 26 is taken up between rollers 36, 37, which draw it continuously forward, and so continue the peeling apart of the sheets. The separating methods of the invention may also be applied to apparatus in which the exposed sheet is actually passed through the developing liquid, and to arrangements where the developing liquid is contained in a rupturable capsule between the two sheets. In the modification of Figs. 7 and 8 (not shown), the separated sheets are conveyed out of the apparatus in opposite directions.