GB202415A - Improvements in and relating to photographic dark slides - Google Patents

Abstract

202,415. Pack, W. May 19, 1922. Dark-slides; envelopes.- Relates to dark slides for a plate or film in an envelope which is positioned on the sliding cover of a magazine container by a frame attached thereto, the plate or film being passed into the container after withdrawing the envelope cover for exposure and by drawing the sliding cover. In the present construction a detachable frame 21, Figs. 5 and 8, slides on either side of the container 70, by edge grooves 17 and 19 or 18 and 20, and has a hinged frame 27, Fig. 3, fitted with springs 34, 35 and 32, 33 on opposite sides which press the edges of the film on to the sliding cover 8 and press the plate or film into the container after exposure and withdrawal of the cover. The springs 34, 35 have upturned flanges 36, 37 on which the envelope is placed with the frame 27 in open position, as shown in Fig. 8, and while serve to guide the film past the grooves in which the covers 8 slide. A pin 38 on the frame 27 pierces the envelope and engages a perforation 43, Fig. 9, in the film 40, or in a hole 77, Fig. 10, of a plate 75 attached to the glass plate 80. The edges 41 of the film or of the attached plate 75 cut the edges 61 of the envelope 55 when the latter is withdrawn as shown in Fig. 5. For plates in envelopes the frame 21 is placed in the grooves 18, 20, Fig. 8, which are located nearer the edge of the container frame than the grooves 17, 19 to allow for the difference in thickness. To retain the plates or films in the container, and prevent them getting into the grooves for the sliding covers 8, spring-controlled catches 65, 66 are provided on the inner faces of the container.