GB298965A - Improved apparatus for photographic developing - Google Patents

Abstract

298,965. Hall, B. J. July 18, 1927. Continuous apparatus for doveloping. - As the prints travel through the apparatus, they are rubbed by an impregnated developing roller whose peripheral speed is different from the speed of the prints. The apparatus in one form comprises a revolving drum A, Fig. 1, in contact with which rotate a feed roller B, a developing roller D, a damping roller or pad F which may be raised by hand or mechanically from contact with the drum, and removable absorption rollers E to remove surplus developer from the prints a'. The drum and all the rollers are covered with fabric. The developing roller D is gear-driven so as to rotate in the opposite direction to the drum A with a peripheral speed slightly greater or less than that of the drum. The remaining rollers are driven by frictional contact with the drum. The covering of the drum A may be flexible, and may be passed round an idle roller near the roller D to increase the area of contact with this roller. To this covering may be attached a raised celluloid strip between which and the covering 'the edges of the prints are gripped. Alternatively, the periphery of the drum may comprise peripherally sliding sections, between any adjacent pair of which a print may be gripped. When developing continuous lengths of prints, this function is performed by the damping roller or pad F. A small roller running at high speed contrary to that of the print may be mounted adjacent to the drum to detach and discharge the prints therefrom. Developer may be applied to the roller D by a squeegee inclined to the roller to form a trough into which the liquid is poured; or the idler may be hollow and perforated, with a tubular spindle through which liquid is introduced; or it may dip into a trough of developer, or rotate in contact with an idle roller which is in contact with a roller dipping into the trough. Additional idlers are used if more than one developer is required, or if the prints are to be intensified. In a modification,. the drum A is replaced by a travelling band working over a stationary table, and the band may be made in sections which open apart where the band passes round its driving rollers, but close together elsewhere, so that the edges of the print may be gripped between two sections. In another modification, the drum A is replaced by a reciprocating table L, Fig. 8, and the prints may be prevented from adhering to the rollers D, E, either in thisform or in the drum form of apparatus, by circular rings d' of longer diameter inserted in peripheral grooves in the rollers.