GB191317015A - Improvements in and relating to Loading, Transferring, Developing and Fixing Photographic Plates and Films in Daylight. - Google Patents

Abstract

17,015. Adair, H., [Adair, A.]. July 24. [Cognate Application, 2076/14.] Envelopes, plate and like; focusing-devices; dark slides.-In lighttight envelopes of the type employed for loading and unloading cameras, dark slides, developing and fixing tanks, &c. in daylight, an envelope 1, preferably of stiff material, is provided with a rigid sliding sleeve 3 and a flexible fabric sleeve 4, which is crumpled to form a light - tight closure when the sleeve 3 is caused to slide inwards and is straightened out to allow the passage of the plate into or out of the envelope when the sleeve 3 is caused to slide outwards. In the modification shown in Fig. 8, the envelope 1 has a chambered and apertured end 15, in which slides a velvet-covered spring sleeve 16, the inner ends of which converge when the sleeve is pushed inwards. In a camera back, Fig. 12, for use with such envelopes, a focusing-screen 29 is held back against the action of a spring 30 by means of a lever 32 and a catch 34, to allow the free passage of a plate into and out of the camera back through lips 11, and is adapted to press the plate into the exposure position when the lever 32 is freed from the catch 34. A dark slide is also described having a spring-pressed light-tight presser-board adapted to hold the plate in position for exposure and to spring back, when released, to allow the free passage of the plate.