Patent GB-191203199-A (GB)
Title: Improvements in and relating to Photographic Plate Packs and Adapters therefor.
Inventor: VARNALS DORA
IPC: G03B17/34
Filed: 1912-02-08
Granted: 1913-02-06
Abstract: 3199. Varnals, D. Feb. 8. [Cognate Application, 5290/12.] Change-boxes, self-contained.-The plates are packed in a case of cheap material comprising two telescopic parts A, B, Figs. 2 and 3, which have all the catches and mechanism necessary to change the plate and which are adapted to be used with an adapter also formed of the telescopic parts K, L, Fig. 16. These parts are adapted to be connected to the respective parts of the inner case and are provided with necessary shutter slides. The outer case A has an exposure aperture a and internal stops a' on the sides, which engage corresponding stops b<2> on the outside of the part B, to prevent the parts from being drawn out too far in changing a plate. The plates rest on two ledges d<8> formed on two plate carriers D, which slide down the sides of the inner case B. The front edges d<1>, Fig. 5, slide between the narrow side flanges adjacent to the front opening b of the inner case B and two strips b<5> which are attached to and overlap the ends of a cross-piece b<4> on the upper end of the part b and of the same thickness as the edge d'. The rear ends d<2> each carry a spring d<3>, Fig. 2, which is detachably secured thereto. The ledges d<8> leave room for one plate to pass in front and behind, the front plate of the pack being unsupported except by being pressed against the open front b by the springs d<3>. The strips D are fitted with ribs to separate the sides of the plate from the sides of the case. A sloping block F is fitted at the inner end of the part b and raises the rear plates above the level of the ledges d<8>. The block is fixed in place by the frame E. The stamped-up tongues e<4> engage in the block, and the tongues e<3> are bent over to form a lighttight joint along the edges of the bottom of the part B. The projecting tongues e<1>, d<10> of the parts E, D are for the purpose of attaching the inner package to the adapter. The top of the pack is closed by a cover G with padded slots for the tongues d<10>, and a projecting face g<3> which lies adjacent to the strip b<4> and between the strips b<5>. The cover G extends below the level of the strips. In assembling the parts, the inner part B is fitted with the internal fittings and the outer part a is sprung over the stops b<2>, a sliding sheet having a white face for recording exposures being slid up between the openings a, b. The front plate in the pack is a dummy plate. On pulling apart the tongues e<1>, d<10> as far as the stops a<2>, b<2> allow, the strips b<5> engage the front plate and separate it from the rest of the pack, which is retained in the outer part a. The case is turned to drop the plate to the back, and on returning the parts the plate is returned at the back of the pack. The plates are packed in such a way that the emulsion side is not rubbed or scratched in changing. A blank H, Fig. 13, of black paper having a matt surface on one face and a hot pressed or rolled surface on the other is secured by a temporary adhesive to the plate. The verlapping edges are folded over the front of the plate, and the ends h' are folded over along the back edges to form runners for the plates. alternatively, a backing of black or non-actinic paper is secured to the plate, and the runners are secured on this backing. The part K of the adapter is fitted with light padded grooves to take an exposure slide k<5>, and the part L is fitted with internal and external padded troughs l<4> to form a light-tight fitting for attachment to the camera when the part K is pushed home. Grooves n, Fig. 17, are provided at the back of the part L for inserting a card on which the exposures are recorded. The card is supplied with the pack and is housed between the openings a and b. The upper part of the back contains a counting-mechanism, the counting-wheel m<4> being given one step movement by the action of a projecting part m<7> on the slide m each time the inner part K is pushed home. The part B is secured to the part L by means of a false bottom l<6>. The tongues e<1> are passed through the slots l<7> and corresponding slots in the part L, and are bent over and secured by a screw bolt l<12>, which screws up into the bush l<8>. An additional fitting l<9>, Fig. 22, with light-trapped slots l<10> is inserted between the bottom of the part L and the piece l<6>. The part A is secured to the part K by a similar false top. The tongues d<10> pass up through the light-trapped slots k<7>, and are bent over and secured bv a screw bolt k<11>.