GB1096830A - Photographic developing machine - Google Patents

Abstract

1,096,830. Photo-copying apparatus. J. HALDEN & CO. Ltd. Oct. 11, 1965 [Oct. 15, 1964], No. 42040/ 64. Heading G2A. The ammonia developing section of a photocopying machine comprises a tank 10 having an entrance in one side 12 and containing conveyer means 11 which carry an exposed copy sheet in a U-shaped path inside the tank so that the sheet is acted on by ammonia vapour within the tank, there being sealing means 20, 21 to substantially prevent the escape of ammonia vapour from the tank when the sheet enters and leaves. A copy sheet and an original are fed in contact by a conveyer 72 around a revolvable transparent cylinder 75 containing an arc tube 76 which exposes the copy sheet through the original. The original is then separated from the exposed sheet by an air knife 77 and the exposed sheet is fed upwards by the conveyer 72 over a suction box 80 is the developing section, where separator fingers 81 guide the sheet through an inlet 15 into the tank. The sheet is fed between rollers 27, 28, 29 and supporting blades 40, 41, 42, 45, 44, 43, then to fingers 47 and hence out of the tank between outlet seal 21 and perforated plate 16 of a suction box 13, which removes any ammonia vapour which escapes from the tank with the sheet. The sheet depresses a micro-switch 67 which causes a fan 60 to be switched on or accelerated, which fan draws vapour from the vapourizing unit 50 into a tube 66 connected to two transverse perforated tubes 38, thus feeding the vapour under pressure into the bag formed by the exposed sheet to develop the sheet. Depression of the switch 67 may also serve to increase the output of the heater 52 and the input of ammonia liquid by way of the pump 57. On leaving the tank, the developed sheet is fed to one of two delivery positions. The blades 40-45 may be perforated or serrated to permit the free circulation of ammonia vapour.