Patent GB-549173-A (GB)
Title: Improvements in or relating to developing apparatus for photographic film strips
IPC: G03D13/06
Filed: 1941-04-28
Abstract: 549,173. Photographic roll film developing apparatus. STACKPOLE CARBON CO. April 28, 1941, No. 5497. Convention date, May 6, 1940. [Class 98 (ii)] In apparatus comprising a tank having provision for rotatably supporting a film cartridge, a reel for receiving the film from the cartridge, and a film severing member mounted adjacent to the cartridge, means are provided for forcing the film against said severing member after most of it has been transferred to the reel and for locking the film-forcing means in film-cut position. The reel flanges may have internal spiral grooves to receive the film edges, and provision may be made in the tank for bowing the film transversely as it is fed to the reel so that it may engage the grooves. A light-tight cover may be provided, fitted with means for supporting and rotating the reel, means for effecting the severance of the film, means for locking the cover in position, and means for introducing and discharging liquids. In the form shown, the tank 1 has a reel chamber 2 and a cartridge chamber 3. The flanges of the reel 8 are spirally grooved at 10, and one mounted on separate, telescopic, interlocking hubs 12, 13, the hub 13 being hollow to receive a pivot boss 7 upstanding from the base of the tank. A cover 24, fitting the tank light-tight at its edges 67 has an aperture above the boss 7 over which is fitted in lighttight manner a reel-manipulating knob 23, having an axial extension 22 screwed into a bush 21 in the reel hub 13. A concentric knob 33 has a stem 31 passing through the extension 22 and having a screwed end adapted to engage a threaded bush 32 in the boss 7 to lock the cover to the tank. Above the chamber 3, the cover has an aperture through which a cylindrical filmcartridge housing 41 may be inserted into the chamber. This housing has a knurled flange 42 resting light-tight on the top of the cover 24, and its upper end is closed light-tight, when the film is to be wound from the cartridge to the reel, by a knob 47 having a stem 50 adapted to grip the cartridge 4. With the cover and attached reel and cartridge housing removed, the film is threaded on to the reel, its end being held on the reel hub by a roller 18 supported on the reel flanges in slots 17 which are inclined to provide a clamping action. The assembly is then placed on the tank, and the locking-knob 33 operated. Within the tank are ribs 52, 53 which serve to bow the film transversely as it is wound from the cartridge to the reel by operating the knob 23 On the wall of the chamber 3, near the film slot 44 of the cartridge housing 41, is mounted a knife 56, and the housing carries a rib 57, recessed at 58 to receive the knife, and serving to force the film against the knife to sever it when, on completion of the film-winding movement, the housing 41 is given a slight turn by operating the knurled vange 42. A ball click 62 on the flange co-operates with a pair of recesses on the cover to limit the turning movement. When the film has been so cut, the housing 41 is in a position in which the knife and the wall 3 of the chamber prevent ingress of light through the film slot 44, so that the knob 47 may be safely removed to permit the introduction of developing &c. liquids through the open top of the housing. The liquids pass into the tank through an aperture 43 in the wall of the housing, escape of air from the tank being facilitated by providing bosses 69 at intervals around the base of the light-trap channel 66 round the cover. The liquids are poured out through the open top of the housing, any liquid which enters the channel 66 being poured off at the same time through a spout 68. A key 36, as described in Specification 549,174, co-operating with the coverlocking stem 31 and with a recess 39 in the cover, may be provided to lock the reel 8 against turning when the cover is unlocked, in order to facilitate threading the film on to the reel. Reference has been directed-by the Comptroller to Specification 466,319.