GB275349A - Improvements in or relating to methods of development of photographic film or the like and apparatus therefor - Google Patents

Abstract

275,349. Stringer, H. B., and Stratton, A. May 17, 1926. Developing-apparatus for roll films.-A photographic roll-film or paper strip is developed &c. by winding it upon itself from one spool to another while maintained completely immersed in the developer &c. In the apparatus shown, the spools 2, 3 are detachably mounted in a tank 1, and either is adapted to be rotated by a handle 21 on a gear wheel 18 connected, as through a friction clutch comprising discs 22, 23 pressed together by a spring 24, to a shaft 13 carrying a disc 15 having projections 16 which engage re - cesses in the end of the spool and transmit the drive thereto. An intermediate gear wheel 19 may be provided to transmit the drive from one spool to the other. To connect the ends of the film &c. to either spool, this may be slotted as at 34 and surrounded by a sleeve 35 slotted at 36 along a generating line. With the slots 34, 36 in register the end of the film &c. is inserted in the slot 34, and the sleeve is rotated to grip the film &c. between the sleeve and the body 7. The film &c. is so wound that its sensitive surface faces outwards, and it is wound continuously back and forth from one spool to the other until developing, fixing &c. is complete. It is left slack between the spools before winding commences to compensate for the tautening which occurs as film accumulates on the wind-on spool. This tautening action is used on completion of the liquid treatments to squeeze out water from the film &c. A light-tight cover, held in position by clips, permits development in daylight and has a filler tube having a capped inlet and communicating with the tank. An outlet for the liquids may also be provided. In apparatus for treating narrow material, the axes of the spools may be in alignment, and guide rollers may be provided for guiding the film &c. between the spools.