| 摘要 |
982,848. Radiographic film holders. GENERAL MAGNAPLATE CORPORATION. Jan. 23, 1962 [Jan. 24, 1961], No. 2411/62. Heading H5R. A film holder comprises a pair of flexible sheets overlying each other (between which the film is interposed), and connected together so as to allow relative movement only longitudinally, at least one of the sheets being a unitary structure including both a layer of a flexible crease-resistant opaque material and also an intensifying screen. The form shown comprises a pair of thin sheet-like members 12, 14 of flexible crease-resistant material. The longitudinal edges 26, 28 of both sheets are bent into a Z-shape, the two Z-shaped edges engaging as shown. Thus the two sheets can slide longitudinally with respect to each other, while the space between them is maintained light-tight. In this space is disposed the film 16. Each sheet member has a surface layer of material 18 acting as an intensifying screen, and a light-opaque layer 20 which may be aluminium foil, with an intermediate layer 22 of a crease-resistant plastics material. Between each of the adjacent layers 18, 22 and 20 is a thin lamination of a soft pliable material 24 such as polyethylene, which facilitates the bonding together of the layers. The total thickness of the holder, including the film, is less than 1/32 inch. A continuous length of the holder may be spooled into a roll (Fig. 6, not shown) and lengths cut off as required. The end of a severed length of the holder may be closed in a light-tight manner either by a suitable closure cap, or by sharply folding over the end. Fig. 7 (not shown) illustrates the holder wrapped round a cylinder or pipe under radiographic inspection. The edge of the holder may be marked with indicia, which will subsequently appear on the film, so that the position of any flaws in the pipe which show up on the film may be located more readily.
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