Patent GB-190525857-A (GB)
Title: An Improved Method of and Apparatus for Developing Photographic "Roll Films".
Inventor: KELLY WILLIAM FRASER CLAUGHTON
Filed: 1905-12-12
Granted: 1906-12-12
Abstract: 25,857. Kelly, W. F. C., and Bolas, T. Dec. 12. Cameras; roller slides; trays, dishes, &c.- A method of and apparatus for developing photographic roll films is described, in which the film is caused by mechanical means to traverse a special developing-dish. At each side of the trough a, Fig. 2, are provided pins b, on which spools for roll films can turn. The ends of the trough are formed with wells a', Fig. 3, and a valved aperture a<2> is provided for emptying the trough. A spool bearing an exposed film having been placed on the pins b at one end of the trough, an uncharged spool is placed on the pins at the other end and the protective black band d is detachably attached to the core of the uncharged spool. Developing-solution having been poured into the trough a, the backing d is wound on to the uncharged spool, the film travelling with it. This winding is continued to and fro until development is complete. The band d supports the tension of winding and may be replaced or supplemented by textile material, celluloid, or the like. The sensitive film may conveniently be attached to the backing by a strip of surgical plaster, or the backing may be perforated to allow one end of the film to be passed through and keyed in position. To relieve any strain on the film a suitable mechanical device may be used to drive one spool from the other, such as grooved wheels in the grooves of which runs a band of the same length and thickness as the roll film so that its movement as it winds and unwinds corresponds exactly with that of the film. In the simple form in which there are two unconnected spools each having a handle, the tension in the film may be partly relieved by providing each with a free-wheel or ratchet so that the handle does not rotate when the spool is unwinding. The trough may be constructed to the dimensions of a roll-film camera back, in which case exposures are made in the trough, or, as then used, the camera back, which must be provided with the usual inspection chamber for viewing the numbers. The trough is provided with a lid a3 having a red window a<4> for viewing the progress of development, and means a<5> are provided for pouring in liquid. The end plates c<1> of the spools are slightly convex, and are adjustable along the core to enable films of varying width to be treated. In Figs. 1 and 4 is shown an arrangement to permit of a single handle driving each spool alternately. The handle rotates freely on a pin, one limb h of an anchor pawl h<1> engaging a ratchet-wheel i<1> on the spool axle. When the anchor pawl h<1> is shot over, the limb h<2> engages a second ratchet-wheel i<1> attached to the side of a loose driving-drum g<x>, which by means of a band f<x> drives a similar drum at the other end of the trough, and thereby drives the second spool. To ensure immediate and thorough wetting of the film surface, a detachable brush bears gently on the film. For convenience in loading or unloading the spools, the centres are coupled by yielding connexions k which permit of slight relative motion.