Abstract:
A reusable cassette for containing and dispensing rolls of photosensitive film may be easily reloaded by the user. The cassette includes a self-centering drum mechanism to accommodate film rolls of different widths.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates generally to cassettes for containing and dispensing photosensitive film material and, more particularly, to a reusable cassette that can be reloaded with a roll of film by the user.  
         BACKGROUND AND SUMMARY OF THE INVENTION  
         [0002]    Disposable cassettes are known in the prior art for containing and dispensing rolls of photosensitive film used by the printing industry in image setters like the DPM 2340 manufactured by A.B. Dick Company, for example. Typical of such prior art cassettes is that described in U.S. Pat. No. 4,842,211 to Robbins. The film cassettes commercially available today are expensive because they are proprietary to the current single-source manufacturer, are disposable, and, therefore, do not permit reloading with film of the user&#39;s choice. Thus, the user of these disposable cassettes would experience a shutdown in his printing operations during periods of short supply or total unavailability of cassettes. Moreover, the disposal of these cassettes, which are fabricated of cardboard, plastic, and foam rubber, presents an environmental concern.  
           [0003]    It would therefore be advantageous to provide a reusable cassette in accordance with the present invention for containing and dispensing rolls of photosensitive film. An exhausted roll of film may be easily replaced by the user with a new roll, and the cassette will automatically accommodate film rolls of different width. The reusable film cassette of the present invention allows the user to obtain photosensitive film from any one of multiple vendors, thus reducing cost and avoiding reliance on today&#39;s single source of disposable film cassettes.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]    [0004]FIG. 1 is an overall pictorial diagram of a reusable cassette for containing and dispensing a roll of photosentive film, in accordance with the present invention.  
         [0005]    [0005]FIG. 2 is a pictorial diagram of the reusable cassette of FIG. 1, with the cover cut away to illustrate the details of the interior self-centering drum mechanism.  
         [0006]    [0006]FIG. 3 is an exploded view of the reusable cassette of FIGS. 1 and 2, with the cover removed.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0007]    Referring now to FIG. 1, there is shown an overall pictorial diagram of a reusable film cassette  100  for containing and dispensing a roll of photosensitive film  10 . Cassette  100  includes a pair of end caps  12 ,  14  and a cover  16  positioned therebetween. Cover  16  includes a frontal longitudinal film slot  18  through which film  10  exits cassette  100 . A foam rubber covered cloth material is preferably positioned along film slot  18  to provide a light seal to prevent exposure of film  10  within cassette  100  that would othewise be caused by the entry of light through film slot  18 . End caps  12 ,  14 , as well as cover  16 , may be conventionally fabricated of any of a number of plastic materials, such as Lexan, for example.  
         [0008]    Referring now to the detailed pictorial diagrams of FIGS. 2 and 3, each of the end caps  12 ,  14  includes an inwardly facing groove  20  along its peripheral edge, into which corresponding ends of cover  16  fit. Cover  16  is fixedly attached to end cap  12  by means of an adhesive or other means. A rod  22 , centrally positioned between end caps  12 ,  14  serves to secure end caps  12 ,  14  in spaced relationship to each other. One end of rod  22  is fixedly attached to end cap  12  by means of a bolt or other fastener  24 , while the other end of rod  22  is removably attached to end cap  14  by means of a thumb screw  26 , for example. Each of the end caps  12 ,  14  includes an inwardly facing, circular protrusion  28  over which are fixedly mounted respective outer ends of a pair of drum members  30 ,  32  that, when butted together as illustrated in FIG. 2, form a circular drum. Drum members  30 ,  32  may be conventionally fabricated of a transparent plastic or other desirable material. A circular film centering member  34  is positioned on rod  22  within drum member  30  proximate end cap  12 . A second circular film centering member  36 , constructed like film centering member  34 , is similarly positioned on rod  22  within drum member  32  proximate end cap  14 . The diameter of film centering members  34 ,  36  is selected to be slightly smaller than the inner diameter of drum members  30 ,  32  so that film centering members  34 ,  36  can move longitudinally within drum members  30 ,  32 , respectively. Each of the film centering members  34 ,  36  includes a plurality of longitudinally and outwardly extending foot members  38 . The outwardly extending portion of each of the plurality of foot members  38  is positioned for travel within a corresponding plurality of longitudinal slots in drum members  30 ,  32 . The longitudinal distance between inner ends of a corresponding pair of the slots in drum members  30 ,  32  represents the width of the narrowest roll of photosensitive film  10  to be accommodated within cassette  100 , while the overall length of drum members  30 ,  32 , when cassette  100  is assembled, represents the width of the widest roll of film  10  to be accommodated within cassette  100 . A spring member  40  is positioned between circular protrusion  28  of each of the end caps  12 ,  14  and each of the film centering members  34 ,  36 . The spring members  40  serve to urge foot members  38  of film centering members  34 ,  36  inwardly along the slots in drum members  30 ,  32  and against the respective ends of a roll of photosensitive film when it has been loaded into position over drum members  30 ,  32 . A plurality of indentations  42  on the inner surface of end caps  12 ,  14  receive foot members  38  when a maximum width roll of photosensitive film is loaded into cassette  100 .  
         [0009]    In preparation for loading a roll of photosensitive film  10 , cassette  100  is preferably positioned on end with end cap  12  resting on a flat surface. Thumb screw  26  is then removed, and end cap  14 , with drum member  32  fixedly attached thereto, is also removed. A roll of photosensitive film, typically supplied on a spool, is then positioned over drum member  30 , the free end of the film  10  is then guided through slot  18  in cover  16 , end cap  14  is placed into position with drum member  32  inserted within the spool on which the roll of photosensitive film is supplied, and thumb screw  26  is tightened. Each roll of photosensitive film preferably includes a daylight leader which allows the user to load the roll in normal ambient light, without the need for a darkroom. Subsequent rolls of film are loaded in the same manner. While the present invention has been described in the context of photosensitive film, it should be noted that cassette  100  may be used to contain and dispense rolls of other types of film materials, as well as other sheet materials, such as paper.