GB541889A - Improvements in or relating to rapid photographic processing apparatus - Google Patents

Abstract

541,889. Photographic film processing apparatus. BAIRD TELEVISION, Ltd., and COLLIER, T. W. June 14, 1940, No. 10361. [Class 98 (ii)] The apparatus comprises an inner cylindrical casing, disposed in use with its axis horizontal, and having a helical channel along which the film is continuously driven, and an outer casing forming a liquid-tight closure with the channel, the convolutions providing a series of compartments in which successive treatments may be applied to the film. In the form shown, for processing kinematograph film, the channel is formed by an inner tubular member 1 having a helical rib 2 the edge 3 of which may be covered with rubber making liquid-tight contact with an outer cylindrical casing 4 the axis of which is horizontal in use. The member 1 is slotted between the helical turns to afford egress by way of the bore 22 for developing &c. liquids introduced through pipes 18, 20, 21 into the various chambers between the turns ; and it is preferably eccentrically disposed above the axis of the casing 4 in order to provide for a greater depth of liquid in the chambers. The film 10 is fed by a sprocket 8 through an aperture 11 into one end of the casing 4, and its edges engage in continuous slots 5 formed in the sides of the helical rib ; it is driven along the helical channel by sprockets 7 on a hand or motor driven shaft 6 geared at 9 to the shaft of the sprocket 8 ; and it leaves the other end of the casing 4 through a slot 12 after treatment. Chambers 13 and 14 may be interconnected and contain developer, 15 and 17 may contain washing water, and 16 fixing liquid. Drain cocks are provided in the base of the casing 4. For cleansing, the apparatus may be flushed by water fed into the pipe 22 and leaving by way of the drain cocks. An additional compartment may be provided through which air is circulated for drying the film. In a modification, the channel is formed by a drawn section of sheet metal helically wound on an inner casing, the adjacent turns being held in place by a continuous helix of moulded rubber wound therebetween. In this form, the various liquids are fed into the chambers formed by the convolutions by pipes within the inner casing, and overflow therefrom through outlets directly into said casing, drain cocks being provided as before in the base of the outer casing.