GB563922A - Improvements in and relating to carriers or holders for plates and films in photographic and like projecting apparatus - Google Patents

Abstract

563,922. Optical-projection apparatus; photographic enlargers. CLEMENTSON, J. S. May 18, 1943, No. 7905. [Classes 97 (i) and 98 (i)] A carrier for centring a plate or film in a photographic or like projecting apparatus, of the kind comprising a pair of adjustable cross slides, one of which is carried by the other and is adapted to receive a plate or film holder, is provided with ineans for attaching it in a lighttight manner to the bellows or tubular body carrying the lens of the apparatus, and one of the slides is provided with means for making a light-tight engagement with the front of the light chamber. In the form shown, the carrier comprises a frame a in the front of which is an aperture b which receives the usual frame attached to the rear end of the bellows or tubular lens-carrying portion of the enlarger, the parts being then secured together by moving plates c slidably mounted on the frame a at the vertical edges of the aperture b so that they engage over the edges of the bellows frame. Within the frame a is a horizontally adjustable slide.d, d<1> between the upright members d of which is mounted a vertically-adjustable slide g. On the rear face of this latter slide is carried an apertured metal plate m, spaced from it by strips k, k<1> so as to form open-ended horizontal channels into which may be slid a plate or film holder n. The plate m bears on a velvet or like facing around the aperture in the front of the light chamber to ensure lighttightness. The sliding edges of the slides are metal faced, and spring-pressed balls (not shown) in one edge of each take up slackness in the movement. The slides are moved by rods e, h which are held in the adjusted position by pinching screws f, j, or may alternatively be threaded into nuts so that adjustment is performed by rotating them.