Film cassette

#This invention relates to film holding apparatus and more particularly to cassettes for holding radiographic film.

#There has been developed a film cassette for x-ray or other radiographic film which is of unique, light-tight construction and is extremely simple to use. Representative cassettes of this type are disclosed in Harry S. Wolf U.S. Pat. No. 2,213,437 granted Sept. 3, 1940. Such cassettes customarily include a front panel and a back panel having a felt cushion. The film is positioned between intensifying screens located intermediate the two panels. The cassettes commonly are stored within the screens and film in place on shelves in radiographic rooms or other locations with only the edges of the cassettes visible. When a picture is to be taken, an orderly or technician selects the cassette with the appropriate screen and film combination, and the picture is made.

#Heretofore, difficulties have been encountered in the construction and handling of film cassettes and similar film holding apparatus. Of particular importance is the need for rapidly and accurately identifying a given cassette and distinguishing it from the comparatively large number of adjacent cassettes at the storage location. In the making of an x-ray picture, for example, one of the more significant parameters is the speed of the screens within the cassette, and it is important to determine the screen speed quickly and without excessive handling. Also, information often is needed concerning the particular department or radiographic room in which the cassette has been stored, the type of cassette, e.g. photo-timing, grid cassette, etc., or other factors necessary or desirable to determine selected parameters consistent with the purpose for which the cassette is employed. Prior cassettes have proved deficient in these respects, with the result that in several instances the cassettes have been incorrectly identified and a substantial amount of time was wasted before the proper cassette could be located.

#FIG. 1 is a perspective view of a cassette for holding x-ray film in accordance with one illustrative embodiment of the invention.

#FIG. 2 is a plan view of the back of the cassette.

#FIG. 3 is a sectional view taken along the line 3--3 in FIG. 2.

#Referring to FIG. 1 and 2 of the drawings, there is shown a cassette for x-ray film which includes a rectangular cover panel 10. The panel 10 is provided with the usual D-shaped ring 11 for opening and closing the cassette and with two hinges 12 and 13 along the edge of the panel opposite that adjacent the ring 11. Two leaf springs 15 and 16 are pivotally supported on the panel 10 intermediate their ends for movement between the full line position shown in FIG. 2 and the dotted line position. These springs serve to hold the panel in place when the cassette is closed.

#The hinges 12 and 13 are connected to one side of a hollow rectangular frame 20. As best shown in FIGS. 4 and 5, the frame 20 is of rectangular cross section, and each of the four sides of the frame is formed from a single sheet of stainless steel, for example. Each of the frame sides has an inner leg 21, a rear face portion 22 defining part of a back opening 23, an outer edge portion 22 defining part of a back opening 23, an outer edge portion 24 and a front face portion 26. The outer edge portions 24 extend in flat planes perpendicular to the plane of the cover panel 10 and meet at the four corners 25 of the frame. The front face portions 26 define a front opening 27 for the cassette which is smaller than the back opening 23.

#A generally circular indentation 30 is provided in each of the edge portions 24 of the frame 20. The indentations 30 are arranged in pairs adjacent oppositely disposed corners 25a and 25b (FIGS. 1 and 2) of the frame. Each indentation is disposed in close proximity with but is spaced from the adjacent corner.