Patent GB-805639-A (GB)
Title: Apparatus for the production of photographic copies
IPC: G03B27/30
Filed: 1956-01-19
Abstract: 805,639. Photographic contact printing and migratory transfer apparatus. SCHWIENBACHER, G. Jan. 19. 1956 [Jan. 26. 1955], No. 1868/56. Class 98(2) In a combined contact printing and migratory transfer apparatus wherein the original and negative printing paper are passed by an endless band round a rotating cylinder for exposure, the original and negative are separated after exposure and the negative is passed to the transfer apparatus whereupon the positive transfer paper is introduced, the papers are caused to pass through the developer bath so that both sides of the exposed paper but only the transfer side of the positive paper are wetted and the papers are then pressed together. The apparatus has as additional features a container for the developer liquid which can be removed downwardly from the apparatus; a reserve container which is connected to the developer container and can be compressed or released to fill or empty the latter; a motor to drive the conveyer band of the printing apparatus and all the necessary rollers and feed means of the processing apparatus; a switch for the motor and the exposure lamp which is actuated by introducing the original and negative papers, and additional means to keep the lamp energized at least until the original and negative papers leave the printing cylinder and to keep the motor energized until the finished prints emerge from the apparatus. As shown (Fig. 1), the original and negative materials are introduced at 33 and contact the switch 31 which energizes the lamp and starts the motor 36. The latter drives roller 42 and the material is carried round the exposure cylinder 5 by an endless belt. On emerging on to the plate 6, the original is ejected upwards at 7 and the exposed negative moves on under the roller 9 and contacts the arm 10 of a double armed lever, the other arm 12 of which moves a slide 13 and permits a positive transfer paper 15 to fall between the rollers 16, 17. The positive paper is conveyed between rollers 20, 21 where it is wetted on one side with developer from tank 3 while the negative passes under roller 21 and is immersed in tank 3. The papers are brought together and passed between rollers 22, 23 to effect migratory transfer. Rollers 9, 17, 21 and 22 are all driven from motor 36, and this is kept energized after switch 31 has opened by means of contacts 35<SP>11</SP> (Fig. 3) and slip ring 34<SP>11</SP> on a disc 34. These contacts are in parallel with switch 31 and the disc 34 is driven from roller 42 at such a rate that the motor remains energized until the papers emerge at 45. A further contact 35<SP>1</SP> and slip ring 34<SP>1</SP> keeps the lamp energized until the original and negative paper have left the exposure cylinder. A compressible reserve liquid container 24 (Fig. 3) is connected to the bottom of tank 3 at 25 and liquid is forced into the tank 3 by depressing button 28 against the action of spring 30 whereby the plate 26 is forced against the container 24. In another embodiment, the positive paper is introduced by rotating rollers 16, 17 once every complete cycle by a multilated sprocket and pin on roller 16 which co-operate with a chain used to drive the other rollers and a second pin on the chain. The disc 34 and its slip rings are then replaced by a switch in parallel with switch 31 and which is normally closed, but is opened by the pin on the sprocket chain as the papers emerge at 45.