GB682268A - Improvements in or relating to photographic film processing tanks - Google Patents

Abstract

682,268. Photographic developing apparatus. NEVILLE BROWN & CO., Ltd., and JOHNSONS OF HENDON, Ltd. April 13, 1951 [April 14, 1950], No. 9229/50. Class 98 (ii). The apparatus comprises a tank and a filmcarrying spool removably retained and axially slidable therein, including resilient means interposed between the tank and the spool, whereby when the spool is urged axially from a normal position and then released, it is then returned to the normal position. As shown, the tank comprises a cylindrical body 1 with a light-trapped lid 2, enclosing a film-carrying spool 3, all made of moulded plastic material. Spool 3 has a hollow spindle 6 carrying discs 7, 8 with spiral grooves 9 for engaging the film edges, the discs being perforated at intervals along the grooves to allow passage of processing liquids. A stud 12 passes through a ring 11 carried by projections 10, and a stainless steel spring 13 bearing at one end against an internal shoulder 14 of spindle 6 and at the other end on one end of stud 12, pushing a flange 12a of the stud against ring 11. The ring 11 and projections 10 are surrounded by a wall 16 having ribs 15a, which fits into a well 15 to locate the spool. Processing liquid may be poured in by a funnel 4, through spindle 6, and passing between the wall of well 15 and the ribbed outer surface of wall 16. A stirring rod (not shown) is inserted into spindle 6 so that its hexagonal end engages the correspondingly shaped shoulder 14, so that the spool may be rotated thereby and may also be given an axial reciprocating movement. Various modifications are referred to : the spring 13 may be replaced by other resilient means, such as a leaf spring; the resilient means may be attached either to the spool or to the base of the tank, or may be mounted freely between them, and may, when the spool has an integral upwardlyprojecting rod, be mounted between the spool and the lid; the spool may have an apron for holding the film instead of grooves; and a number of spring studs may be mounted around the lower disc of the spool, all bearing on the bottom of the tank.