GB667325A - Improvements relating to holder frames for photographic material - Google Patents

Abstract

667,325. Holders for photographic or X-ray sensitive material. METROPOLITANVICKERS ELECTRICAL CO., Ltd. (General Electric X-ray Corporation). Feb. 20, 1950, No. 4316/50. Class 98 (i). A holder frame or cassette comprises a pair of thin, rigid, separable plates which secure a sheet of photographic sensitive material placed between them for exposure to light or to rays such as X-rays, one plate having at least a part transparent to the rays by which the exposure is effected, together with magnetic means whereby the plates are lightly hold together in closed position but so as to permit easy separation. When the exposure is made by X-rays or like radiation both sheets are opaque to light, and light sealing means form a pocket for the sensitive material. As shown, an X-ray cassette comprises plates 12, 13 hinged at 14 and preferably made of non-magnetic material. Plate 13 is made of material permeable to X-rays, such as the reaction product of phenol and formaldehyde; plate 12 may be made of aluminium. A channel member 16 fixed to plate 13 forms a pocket 20 in which a sensitive sheet is laid, and which is closed by an interfitting rib 18 on plate 12 when the plates are brought together. One or more magnets on one plate and an armature on the other hold the plates together ; e.g. magnets 24 are mounted in recesses in the channel member 16, and rib 18 is made of iron or other magnetic material. The cassette is opened by prizing the plates apart with a wedge or like tool, or by placing it in a neutralizing magnetic field. A layer of lamb's wool may be fixed to one plate to press the sensitive sheet, together with intensifying screens, if desired, against the other plate.