Abstract:
A system is provided for movably supporting an ink film in a printer. The system has cylindrical supply and take-up cores for supporting and taking up the film during printing operations. The cores may be made of molded plastic resin. The ends of the cores are sized to selectively fit within a frame in such a way as to provide stable operation, including where applicable, while a frame cover is closed. In a preferred embodiment, the diameters of the first and second ends of the supply and take-up cores are essentially the same, and the diameters of the second and first ends of the respective cores are essentially the same. A molded cylindrical brake portion frictionally contacts the teeth of a brake gear to provide the desired film tension with improved handling and with reduced likelihood of jamming.

Description:
This application is a divisional of U.S. patent application Ser. No. 10/695,838, which was filed Oct. 30, 2003, the disclosure of which is hereby incorporated herein by reference in its entirety. 

   BACKGROUND OF THE INVENTION 
   The present invention relates generally to devices for supporting a flexible film in a printer or the like. The invention also relates to systems for handling flexible sheet material, and methods of selectively providing ink film for printing. 
   SUMMARY OF INVENTION 
   The present invention relates to a system for movably supporting a film, such as an ink film (which may be a contrast agent film) or another suitable transfer medium. According to one aspect of the invention, the system may be used to support the film within suitable packaging such as for display, storage and/or sale. In addition, the system may be used to wind or reel the film in an operative, movable manner within a printer, for example one located within a facsimile machine. The system may be used, for example, to support a film within a printer of the type shown in U.S. Pat. No. 6,543,945. 
   According to a preferred embodiment of the invention, the film support system is made up of first and second rotatable devices, each having first and second ends. The first device may be used to supply the film; the second device may be used to take up or otherwise receive the film from the first device. In the preferred embodiment, the devices may be hollow molded cores. 
   According to another aspect of the invention, the diameter of the first end of the second rotatable device may be essentially the same as that of the second end of the first device, and the diameter of the second end of the second device may be essentially the same as that of the first end of the first device. If desired, the first end of the first device may have a greater diameter than the second end of the first device. If desired, the diameters of the ends may be selected, relative to corresponding support structures in the printer, to provide a quality control function, to ensure that inferior film products are not installed in the printer, and/or to ensure that film is easily installed in the printer in the proper orientation. 
   According to yet another aspect of the invention, a cylindrical brake portion may be provided for frictionally contacting, but not meshing with, a brake gear in the printer, to apply a back tension to the ink film as it is pulled onto the take-up device. In a preferred embodiment, the brake portion is integrally molded as part of the supply device. The cylindrical exterior surface of the brake portion may be concentric with other cylindrical exterior surfaces of the supply device. 
   According to another aspect of the invention, the supply and take-up devices may be used to locate the film within a printer or other machine. If desired, the ends of the supply and take-up devices may be located in suitable support structures or devices, such as, for example, the semi-cylindrical support sections shown in U.S. Pat. No. 6,543,945. According to a preferred embodiment of the invention, a cover may be moved onto the ends of the supply and take-up devices after the ends are located in the support devices, and a take-up gear within the machine may be used to drive the take-up device to take up the film from the supply device. If desired, the brake gear may be used to apply friction to the supply device, to thereby generate tension within the extended portion of the ink film, while the take-up (drive) gear is rotated. 
   These and other objects and advantages of the invention may be best understood with reference to the following detailed description of preferred embodiments of the invention, the appended claims and the several drawings attached hereto. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partially broken away plan view of an ink ribbon supply system constructed in accordance with a preferred embodiment of the invention, with a cover removed. 
       FIG. 2  is a partially broken away left side view of the supply system of  FIG. 1 , with the cover in an intermediate position, moving toward an operative, closed position; 
       FIG. 3  is a partially broken away right side view of the supply system of  FIG. 1 , with the cover in its intermediate position; 
       FIG. 4  is a plan view of the supply core of the supply system of  FIG. 1 , with the ink ribbon removed; and 
       FIG. 5  is a plan view of the take-up core of the supply system of  FIG. 1 , with the ink ribbon removed. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring now to the drawings, where like elements are designated by like reference numerals, there is shown in  FIG. 1  a film support system  10  constructed in accordance with a preferred embodiment of the present invention. A detailed description of the illustrated system  10  is provided below. The present invention should not be limited, however, to the specific features of the illustrated system  10 . 
   The film support system  10  has an ink film  12 , a supply core  14 , a take-up core  16 , and a frame  18 . Rotation of the supply core  14  is braked (that is, resisted but not prevented) by a brake gear  20 . The take-up core  16  is rotated by a drive gear  22 . In operation, rotation of the drive gear  22  causes the film  12  to be taken up around the take-up core  16  while tension is generated within the film  12  by friction between the brake gear  20  and a cylindrical brake portion  24  of the supply core  14 . 
   The film  12  may be formed of a known flexible sheet-like or ribbon printing medium. The illustrated film  12  contains a flexible backing material and a suitable contrast agent such as colored or black ink. A leading edge  26  of the film  12  may be attached to a main portion  28  of the take-up core  16 . An extended portion  30  of the film  12  is stretched between the cores  14 ,  16 . The remainder  32  of the film  12  is wound around the main portion  34  of the supply core  14 . The width of the film  12  is such that it covers all or most of the main portions  28 ,  34  of the cores  14 ,  16 . In a preferred embodiment, the extended film portion  30  is positioned in a printer of a facsimile machine to be operated upon by a printer head (not shown) or the like. As the extended portion  30  is wound around the take-up core  16 , a new extended portion is drawn off from the supply core  14 , such that a fresh film portion is periodically or continuously moved into position adjacent the printer head as desired. 
   The illustrated supply core  14  is a single piece of integrally molded plastic. The core  14  has first and second ends  36 ,  38  in addition to the brake and main portions  24 ,  34 . The four supply core portions  24 ,  34 ,  36 ,  38  have cylindrical exterior surfaces that are concentric with each other. The main portion  34  is located between and is contiguous with the brake portion  24  and the second end  38 . The brake portion  24  is located between and is contiguous with the first end  36  and the main portion  34 . 
   When the system  10  is assembled within a printer, the first and second ends  36 ,  38  fit into respective semi-cylindrical, upwardly open support sections  40 ,  42  ( FIGS. 2 and 3 ) in the frame  18 , and the brake portion  24  is in frictional contact with the brake gear  20 . The supply core ends  36 ,  38  are settled into and rotatably supported on the support sections  40 , 42 , such the frame  18  aligns the centerline  44  of the core  14  on the desired axis of rotation. The brake portion  24  may slip over the brake gear  20  to prevent the system  10  from becoming jammed or stuck as a result of contaminants in the brake gear  20 , or as a result of a malfunction of the brake gear  20 . In addition, since the brake portion  24  does not have any teeth, it is easy to smoothly locate and remove the system  10  from its printing position. That is, an advantage of the illustrated system  10  is that it is not necessary to mesh any teeth into the teeth of the brake gear  20 . 
   The take-up core  16  is a single piece of molded plastic, with first and second ends  46 ,  48  ( FIG. 1 ) and an integrally molded gear  50 . The main portion  28  of the take-up core  16  is located between and is contiguous with the first and second ends  46 ,  48 . The second end  48  is located between and is contiguous with the main portion  28  and the molded gear  50 . The ends  46 ,  48  and the main portion  28  have cylindrical exterior surfaces that are concentric with each other and with the teeth of the molded gear  50 . 
   When the system  10  is assembled within the printer, the take-up core ends  46 ,  48  fit into respective semi-cylindrical, upwardly open support sections  52 ,  54  of the frame  18 , and the teeth of the molded gear  50  are meshed with the teeth of the drive gear  22 . The take-up core ends  46 ,  48  are settled into and rotatably supported on the support sections  52 ,  54  such that the frame  18  maintains the centerline  56  of the take-up core  16  on the desired axis of rotation. 
   As shown in  FIGS. 2 and 3 , the frame  18  has a movable cover  58  with semi-cylindrical openings  60 ,  62 ,  64 ,  66  for covering the support sections  40 ,  42 ,  52 ,  54  to fully enclose the respective ends  36 ,  38 ,  46 ,  48  of the cores  14 ,  16 . The cover  58  has an open position, an intermediate position and a closed position. When the cover  58  is in its open position (not shown), the cores  14 ,  16  and film  12  can be moved into or removed from the support sections  40 ,  42 ,  52 ,  54 , for example to replace a spent or damaged film  12 . The cover  58  is shown in  FIGS. 2 and 3  in its intermediate position, moving in the direction of arrow  68  from the open position to the closed position. 
   In the closed position (not shown), the lower-most edges of the downwardly open semi-cylindrical cover openings  60 – 66  match the upper-most edges of the support sections  40 ,  42 ,  52 ,  54  to form smooth, encircling, rotation-facilitating axle connections between the core ends  36 ,  38 ,  46 ,  48  and the frame  18 . In this way, the cover  58  contributes to the positional maintenance of the core centerlines  44 ,  56  on the desired axes of rotation. In the closed position, lower guide edges  70 ,  72  of the cover  58  rest on corresponding guide edges  74 ,  76  of the lower portion  78  of the frame  18 . 
   If desired, the frame  18 , including the cover  58 , may be constructed generally like the frame (or case) and cover shown in U.S. Pat. No. 6,543,945. According to a preferred embodiment of the invention, and as discussed in more detail below, the lengths and diameters of the core ends  36 ,  38 ,  46 ,  48  are sized to provide stable positioning and rotatability within the frame  18  while the cover  58  is in its closed position. 
   According to one aspect of the invention, however, the radial dimensions of the core ends  36 ,  38 ,  46 ,  48  are not necessarily the same as and do not necessarily match the radial dimensions of the corresponding frame enclosures  40 ,  60 ,  42 ,  62 ,  52 ,  64 ,  54 ,  66 . If desired, the frame  18 , including the cover  58 , may be sized to operatively receive supply and take-up cores that are substantially different than the ones described in the present specification. 
   Referring now to  FIG. 4 , the diameter  90  of the first end  36  of the supply core  14  may be in the range of from about 0.440 inches to about 0.500 inches. In the illustrated embodiment, the first end diameter  90  is about 0.470 inches. The inner diameter  91  ( FIG. 1 ) of the hollow core  14  is selected to provide sufficient wall strength without using an excessive amount of plastic material. 
   The diameter  92  ( FIG. 4 ) of the brake portion  24  is such that the desired friction is applied to the ends of the teeth of the brake gear  20  during operation. The brake portion diameter  92  is greater than the first end diameter  90 . For example, the brake portion diameter  92  may be in the range of from about 0.750 inches to about 0.810 inches. In the illustrated system  10 , the brake portion diameter  92  is about 0.780 inches. 
   Note that the brake portion diameter  92  is preferably selected such that the brake portion  24  is biased in a first direction  93  ( FIG. 1 ) by pressure applied by the brake gear  20 , while the first supply core end  36  is biased in the opposite direction by pressure applied by the encircling frame connection  40 ,  60 . The friction generated where the first supply core end  36  rotatably slides within the frame  40 ,  60  supplements the friction applied to the supply core  14  by the brake gear  20 , and contributes to the stable tension-generating braking operation of the film system  10 . 
   The diameter  94  of the supply core main portion  34  may be less than the diameter  92  of the brake portion  24 . The main portion diameter  94  is selected to provide the desired room for the wound up film  12 ,  32 . In addition, the relative diameters  92 ,  94  of the brake portion  24  and the main portion  34  should be arranged to provide the desired tension to the extended film portion  30  during printing. The main portion diameter  94  may be, for example, in the range of from about 0.720 inches to about 0.780 inches. In the illustrated embodiment, the main portion diameter  94  is about 0.750 inches. 
   The diameter  96  of the second end  38  of the supply core  14  may be greater than the first end diameter  90 , to provide for rotation of the supply core  14  in a stable condition within the frame  18 . The difference between the end diameters  90 ,  96  may also be used to provide a quality control function, to ensure that inferior film products are not installed in the printer, and/or to ensure that film is easily installed in the printer in the proper orientation. The main portion diameter  94  is greater than the second end diameter  96  so that the main portion  34  does not tend to slip into the frame opening  42 ,  62 . The second end diameter  96  may be for example, in the range of from about 0.600 inches to about 0.660 inches. In the illustrated embodiment, the second end diameter  96  is about 0.630 inches. 
   Referring now to  FIG. 5 , the diameter  98  of the first take-up core end  46  may be essentially the same as the diameter  96  of the second supply core end  38 . In particular, to provide the desired fit, selective assembly and stable rotation in the frame  18 , the diameter  98  of the first take-up core end  46  should be closer to the diameter  96  of the second supply core end  38  than to the diameters  90 ,  100  of the other core ends  36 ,  48 . In the illustrated embodiment, the diameter  98  of the first take-up core end  46  is in the range of from about 0.600 inches to about 0.660 inches, more preferably, the diameter  98  is about 0.630 inches. 
   The diameter  102  of the main portion  28  of the take-up core  16  may be much greater than the diameter  98  of the contiguous first end  46 , but less than the main portion diameter  94  of the other core  14 . For each core  14 ,  16 , the main portion diameters  94 ,  102  should be essentially uniform across the entire lengths of the main portions  28 ,  34 . Further, the diameter  102  of the main take-up portion  28  should be sized relative to the teeth of the molded gear  50  to provide the desired driving force (torque in the film winding direction). The take-up core main portion diameter  102  may be, for example, in the range of from about 0.675 inches to about 0.735 inches. In the illustrated embodiment, the take-up core main portion diameter  102  is about 0.705 inches. 
   The diameter  100  of the take-up core second end  48  may be less than the diameter  98  of the take-up core first end  46 , to thereby rotate in a stable condition as desired within the corresponding frame opening  54 ,  66 . The take-up core second end diameter  100  may be essentially the same as the supply core first end diameter  90 . In particular, to provide the desired fit, selective assembly and stable rotation in the frame  18 , the take-up core second end diameter  100  should be closer to the supply core first end diameter  90  than to the diameters  96 ,  98  of the other core ends  38 ,  46 . The take-up core main portion diameter  102  may be greater than the take-up core second end diameter  100  so that the take-up core main portion  28  does not tend to slip into the frame opening  54 ,  66 . The take-up core second end diameter  100  may be, for example, in the range of from about 0.440 inches to about 0.500 inches. In the illustrated embodiment, the take-up core second end diameter  100  is about 0.470 inches. 
   In operation, the system  10  may be stored, handled and marketed in a suitable package (not shown). During such storage, the cores  14 ,  16  are located close to each other. Once the system  10  is removed from the package, the cores  14 ,  16  are moved away from each other, such that the film  12  unwinds partially from the supply core  14  to form the extended portion  30  between the two cores  14 ,  16 . While the printer cover  58  is in its open position, the core ends  36 ,  38 ,  46 ,  48  are placed into and maintained by gravity within the upwardly open support sections  40 ,  42 ,  52 ,  54 . Then the cover  58  is rotated ( 68 ) into its closed position, such that the core ends  36 ,  38 ,  46 ,  48  are enclosed within the circular frame openings  40 ,  60 ,  42 ,  62 ,  52 ,  64 ,  54 ,  66 . At this stage, the molded gear  50  is meshed with the drive gear  22 , the cylindrical brake portion  24  is in frictional contact with the brake gear  20 , and the extended film portion  30  is located adjacent the printing head. 
   During printing, the film  12  is periodically and/or progressively transferred onto the take-up core  16  until all or most of the film  12  is wound around the take-up core  16 . Then the cover  58  is returned to its open position, the cores  14 ,  16  and film  12  are removed from the frame  18 , and a new system  10  is positioned within the frame  18  for further printing operations. 
   The above description and drawings are only illustrative of preferred embodiments which can achieve and provide the objects, features and advantages of the present invention. It is not intended that the invention be limited to the embodiments shown and described in detail herein. Modifications coming within the spirit and scope of the following claims are to be considered part of the invention.