GB550726A - Photographic developing apparatus - Google Patents

Abstract

550,726. Photographic developing apparatus. CORNERCROFT, Ltd., and RYCROFT, N. Aug. 22, 1941, No. 10713. [Class 98 (ii)] Photographic developing, fixing, and washing apparatus is provided with a spool having the inside face of each of the flanges thereof formed with a spiral groove, and a correspondingly coiled flexible apron arranged between the flanges with the edges of the convolutions thereof in permanent engagement with the grooves so as to form a spiral passage for the reception of a photographic film. As shown in Fig. 1, the spool comprises a pair of flanges of which the flange 2 is integral with a tubular hub 3 and the flange 4 is slidably adjustable along the hub to accommodate films of different widths.. The inner face of each flange is formed with a spiral groove 5, the inner end of which terminates abruptly to form a stop, and the outer end of which is carried to the periphery and is flared to facilitate the introduction of the film. The apron 9 may be of cellulose acetate, and is pre-formed for arrangement between the flanges of the spool by coiling it on itself with the required number of convolutions. The coil may be dipped first in hot water to soften it and then in cold water to set it. The free end of the hub is threaded externally to receive a nut 10, and a distance piece 11 of an appropriate length for the desired width of apron is inserted between the nut 10 and the flange 4, the apron 9 being maintained in position by pressure between the flanges. At the outer end the spiral passage is closed by a gate 12 pivoted on trunnions 13 between the flanges and provided with recesses engaging projections on the flanges and with a rib forming a stop for the outer ends of the apron and film. The loaded spool is placed in a light-proof container 16, Fig. 3, having a removable cover 17 provided with flanges 17a, 17b cooperating with a channel 16a on the container to exclude light. The cover has a central hollow boss 17c adapted to enter the outer end of the spool hub, the outer end 17d of the boss being cup-shaped to provide a filling orifice. The spool can be rotated or oscillated in the container by a spindle 18 having a forked end 19 engaging a pin 20 fixed transversely in the spool hub. The inner end of the hub has an opening 21 and is supported clear of the bottom of the container by projections 22. A central spigot 23 engages a recess 24 in the hub. The flanges of the spool may have openings to facilitate circulation.