GB739019A - Improved apparatus for making photographic negative and positive copies - Google Patents

Abstract

739,019. Photographic exposing and developing device. SCHWIENBACHER, G. Aug. 24, 1953 [Aug. 22, 1952], No. 23318/53. Class 98 (2). A single unit comprising a glass cylinder with internal tubular lamp and external driving belts for rotation of the cylinder and transport of copy material, and also a developing vessel, is characterized in that the lamp is switched on only during passage of the copy material, in that the lesser light strength at certain parts of the lamp is compensated for by greater permeability of the glass surrounding the filament at such parts, that undesired light strength at the side of the lamp facing the inlet and outlet of the copy material is compensated by a covering therefor, that the driving belts are white and are arranged close together for the purpose of reflecting light, that heating means with an automatic maximum temperature switch is provided underneath the developing vessel, and that a pipe is provided which rises from the lowest point of the developing vessel to above the level of the liquid for convenience in emptying the vessel. Fig. 4 shows the exposing device drawn to a larger scale than the unit as a whole as in Fig. 1, the exposing device comprising glass cylinder c carried by white driving belts mounted on rollers d1-d4 and provided with internal lamp e. Copy material on introduction through slot s1 in a casing a is caused to depress a lever h1 to operate mercury switch f and thereby light the lamp while the copy materials are carried round the cylinder as far as the stripping lug l, at which point contact of the copy materials with a felt strip l1 on the lug l permits release of the lever h1 to extinguish the lamp, and the copy materials pass out through a further slot s2 in the casing a. The developing portion of the unit, Fig. 1, comprises vessel b1 with cover b, heating means i, thermostatic switch i1 and flexible emptying pipe n1. Guiding walls p1-p4 are provided inside the vessel b1 whereby the exposed negative material and also a receiving sheet may be passed through the vessel b1 and then deflected upwards between squeezing rollers k1, k2 to obtain a positive copy immediately from the negative. The rollers k1 k2 are driven by a motor through gearing m1 which is also arranged to drive the belt rollers d1-d4 of the exposing device.