Patent GB-289833-A (GB)
Title: Improvements in tanks for use in the preparation of cinematographic films
IPC: G03D13/04
Filed: 1928-04-27
Abstract: 289,833. Henry, L. May 3, 1927, [Convention date]. Trays, dishes, and containers for roll films.-Apparatus for developing and finishing kinematograph films comprises a set of nesting annular tanks 1, 2, 3, the outer one of which is opaque; a dark box 14 removably mounted in light-tight manner upon the outer tank 1; a drum 4 upon which the film can be wound; means for supporting the drum so that it may be lowered into one of the tanks or raised into the dark box; a partition associated with the support for effecting sliding light-tight engagement with the inner surfaces of the dark box; and means such as a slide for closing the dark box in light-tight manner after the drum has been raised thereinto, and before removing the box from the tanks. When in use, the tanks may be nested, the inner one containing the bath; or the inner tank or tanks when not actually required, may be withdrawn. The drum 4 is built up from a number of apertured panels, which are held together by end rings 6, 6<1> and are so ribbed that, when assembled, a helical groove for the film is formed on the outer surface of the drum. The upper ring 6 is provided with a detachable handle 8 the ends 7 of which serve to unite the drum to its support, which comprises parts 9, 9<1>, 29 having circular ribs 9<4>, 9<3>, 29<1>, the part 29 having also an upstanding flange provided with lighttight packing 30 in frictional engagement with the box 14. On the central part of the support is a knob 11 for hand manipulation of the drum when the cover 14b of the box has been removed, and at the base of the box is a slideway 28 adapted to receive a closure slide when the support and attached drum have been raised into the box. The upper ends of the tanks are of funnel form, and the dark box is secured to the outer tank 1 by a detachable ring 15 having a pin and slot connection 16 with the box. In order that the film may be fed into the apparatus from its exposure magazine 34, Fig. 3, the tank 1 is secured to the dark box, and the magazine is attached by a shackle 18 to a block 17 slidable into a cut-away portion of the dark-box 14. Within the block is a film passage containing a roller 21, and the film is threaded through the passage and secured to the lower end of the drum 4 after having been threaded through a slot 25, Fig. 10, in a guide member 26 which is sprung into the helical guideway at the bottom of the drum. Projections 27, 27' on the guide member 26 serve to lock the member to the block 17, so that when the knob 11 is turned, the drum screws downwards through the fixed member 26 into the tank 1, and draws the film from the magazine 34 into the helical guideway on the drum. When all the film has been wound in, its end is detached from the magazine, and a clip is attached thereto which, on further rotation of the knob 11 is drawn through the passage in the block 17 and is finally caught by the slot 25 on the guide member 26. The guide member is freed from the block 17, to permit rotation, raising, and lowering of the drum, by slightly withdrawing the block 17, the light-closure being maintained by a slide 22 which moves with the block. This slide is mounted on a hinged door 23 and has a pin 32 which engages a hole in the block 17 when the door 23 is closed. The film having been wound, the drum is pulled up by the knob 11 into the dark box 14 and the cover inserted in the slot 28. The ring 16 is detached, and the tank 1 is removed. The particular bath to be employed having been poured into the tank f, or into another tank nesting therein the tank 1 is re-attached to the box 14, the cover is removed from the slot 28, and the drum is lowered into the tank by pushing the knob 11. After treatment, the drum is raised into the dark box, the cover is again inserted in the slot 28, and the tank is removed. Successive operations are similarly performed. The washing operation between the various treatments is performed in the tank 1. For this purpose a sleeve 13 is inserted in the tank before this is secured to the dark box. In operation, this sleeve lies between the drum and the inner wall of the tank 1, and has at its upper end an inwardly bent extension 13<2> perforated at the central part 13<1> which rests in a funnel-shaped extension 1<1> of the tank 1. Water is poured on the flat surface of the support 9, 9<1>, 29 either from a tap or from a wide-necked bottle inverted over the knob 11, and passes, by way of apertures arranged in light-tight manner in the various member 9, 9<1>, 29 into the tank 1, where it flows down the outside of the drum, then up between the sleeve 13 and the inner wall of the tank, and is finally discharged through the apertures 13' into a sink or a bottle resting below the funnel 1<1>. The sequence of operations necessary for developing and chemically reversing a film is described. The Specification as open to inspection under Sect. 91 (3) (a) refers also to a window at one side of the apparatus, to be used in conjunction with a non-actinic lamp introduced inside the drum for inspecting the progress of treatment. It also describes a modified apparatus for dark-room development, comprising a single annular tank enclosing the film-supporting drum with axis horizontal, the outer wall of the tank being formed by a hollow block which can be removed from a surrounding casing when the film is being wound. This subject-matter does not appear in the Specification as accepted.