Patent GB-567142-A (GB)
Title: Improvements in apparatus for processing photographic films
IPC: G03D13/04
Filed: 1943-09-25
Abstract: 567,142. Photographic film-processing apparatus. CORNERCROFT, Ltd., and RYCROFT, N. Sept. 25, 1943, No. 15756. Addition to 551,135. [Class 98 (ii)] The apparatus claimed in the parent Specification is modified in that (1) the loading device derives its traversing motion by direct engagement with the helical film track on the rotating drum ; (2) provision is made for winding two or more films simultaneously from the loading device on to the drum in superimposed but spaced relation; and (3) the drum and loading device are entirely enclosed in a removable outer.casing to permit daylight loading and processing. The Specification describes also a drum formed or provided at its ends with single-turn helical flanges parallel to each other with identical film supports disposed therebetween to define the helical film-track ; and a sump for the processing liquids, into which the periphery of the rotating drum dips, said sump being formed in the base of the apparatus and communicating with an external filling orifice and a valvecontrolled discharge orifice. As shown, a hollow drum of stainless steel, metal rendered acid-resisting, or plastic, comprising two dished parts 2, Fig. 1, either bolted together directly or welded to an intermediate annular member, is mounted on a tubular spindle 24 removably supported in an inner structure 20 surrounded by a casing 22 engaging in light-tight manner a channel 41 in a base 21; and provision is made for rotating the spindle either by a hand wheel 28 or by a detachable power-drive member 29. Parallel, single-turn helical flanges 4 on the drum carry between them a series of identical film supports 5, spaced apart around the drum and having spaced projections 5a provided with undercut film-locating grooves. Slidably mounted on a guide bar 11 supported parallel to the axis of the drum by the structure 20 is a film loading device comprising a sleeve 16 to which is pivoted at 15, Fig. 4, a shoe 10 shaped so as to lie under its own weight or under restraint in the helical track formed by the projections 5a on the drum, and provided at the end remote from the pivot 15 with film guides 12, and between the ends with bearing lugs 19 in which spools of film may be rotatably disposed. The plate 10 is adapted by its contact with the helical track to be traversed along the bar 11 as the drum is rotated, so that, after the leading end of the film 9 has been secured by a clip to one of the film supports 5, the film will be delivered from the spool into the helical track on the drum as this is rotated. The guides 12 on the plate are designed to arch the film transversely as it is fed to the drum to permit the edges of the film to engage the undercut grooves in the projections 5a, thereby dispensing with the need for a clip for the trailing end of the film. When the film has been wholly transferred from the spool to the drum, the loading device continues its traverse until it is shunted past the end of the drum by one of the helical flanges 4. The shoe may be modified to receive two or more spools so that two or more films may be wound simultaneously onto the drum, in superimposed spaced relation, being received on the drum in separate pairs of undercut grooves in the projections 5a. The periphery of the drum dips as it rotates into a sump 32 formed in the base 21 ; processing liquids are introduced into the sump from an external orifice 33 via a pipe 34, and are discharged therefrom through an outlet pipe 48 provided with a spring-biassed valve 35 displaceable by an external knob 37 into open or closed position. Access to the drum is obtained by unscrewing the filling orifice fitting 33, a retaining screw cap 43, and the driving member 47 connected to the drum spindle, thus releasing the outer casing 22 for removal from its supportchannel 41 ; thereafter the drum may be removed by withdrawing a spindle-supporting screw 44 and sliding the spindle 24 out through the bearing 23.