Patent GB-509698-A (GB)
Title: Portable dark room for developing and printing photographic roll films in daylight
IPC: G03D17/00
Filed: 1938-01-17
Abstract: 509,698. Photographic developing and printing apparatus. CERNY, J., and GRINSPUN, I. Jan. 17, 1938, No. 1504. [Class 98 (ii)] A portable device for developing .and fixing roll films and for taking prints from negatives comprises a box 5, Fig. 1, containing trays 31, 32, for the developing and fixing solutions, and having a removable lid 7 provided with an aperture 75 which is closable by a shutter 76, an intermediate lid consisting of a movable part 6" hinged to a fixed part 6<1> formed with a window 56.in line with the aperture 75, and a drawer 35 for containing a roll of printing paper 43. The side wall 3 of the box carries a bearing 27 for an axially movable cranked shaft 24 which extends into the box and on to the end of which may be screwed a drum 15. The bearing 27 is provided with vertical adjustment so that the drum may be lowered into either of the trays 31, 32. The drum, which is used in the developing and fixing of a film, comprises perforated side plates 9, 10, Figs. 5 to 7, separated by a sleeve 11' and detachably connected together by a nut 12 which screws on a rod 11 rigidly attached to the side plate 9. Channel-sectioned spiral grooves 13, for supporting the edges of the film to be developed are provided on the inner faces of the side plates which are also formed with corresponding apertures 18<1>, 19<1> to receive respectively the axles of an exposed spool 18 and an empty spool 19, the drum being dismantled' to insert the spools. Before assembling the parts of the drum the outer end of the backing paper of the film on the exposed spool is inserted in the slot in the empty spool. The drum is then assembled and inserted into the box 5 through the movable portion 6<11> of the intermediate lid, the shaft 24 being next screwed into a tapped hole 26 in the rod 11 of the drum. A key extending into the box, but operated from without, is then engaged with the axle of the empty spool and rotated to wind the backing paper off the exposed spool, the film unwinding at the same time and being guided by a plate 17<1>, Figs. 6 and 7, into the spiral grooves 13 of the side plates of the drum. When the film is wholly wound into the grooves, the drum is lowered into the developing tray and, after developing is transferred to the fixing tray. In using the device for taking prints from a negative, the negative is held in a carrier beneath the window 56 of the intermediate lid and the printing paper is held against the negative by a plate 57 which is pivoted about a horizontal axis and adapted to be pressed against the paper by a lever 61 operable from outside the box. After exposure, the plate is released and the print falls into the developing tray 31 and is subsequently conveyed to the fixing tray 32 by a pivoted carrier 86 operated from outside the box. The printing paper, with a backing paper, is contained on a spool 43 and is fed to the exposure window through a slit in the drawer containing the spool, feeding being effected by winding the backing paper on to a spool 44. A knife 52 severs the paper required for each print. In a modified construction the box carries within it a light-tight container for printing paper in sheet form the sheets being brought into position under the negative by hand. The box is provided with a sleeved aperture through which the hand is inserted.