Abstract:
Core and spindle technology for use with ribbon materials. The invention has use in many environments in which a ribbon or sheet material is wound onto a core, for example in printers and related equipment used to produce data bearing identity documents. The core and spindle are constructed to prevent the core from locking on the spindle as a result of the core contracting as ribbon material is wound onto the core. The core and spindle permits contraction of the core without squeezing or binding the core to the spindle, so that the core can easily be removed from the spindle once the ribbon is wound onto the core.

Description:
PRIORITY INFORMATION 
     This application claims the benefit of U.S. Provisional Application No. 60/342,919 filed Dec. 21, 2001. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to consumable ribbon materials, particularly in printers and related equipment. More particularly, the invention relates to an improved core and spindle for ribbon materials used in equipment, such as printers, for producing data bearing identity documents, including cards such as identification cards, drivers licenses, credit cards and the like, and booklets such as passports and the like. 
     BACKGROUND OF THE INVENTION 
     Ribbon materials, such as printing ribbons, cleaning tape, index tape, labels, topping foil, and holographic overlay tape, used in printers and related equipment for producing data bearing identity documents are known. The ribbon material is usually supplied from a supply roll, and, after use, is wound onto a take-up roll. The take-up roll typically comprises a cylindrical core or spool that is mounted on a spindle which is driven in rotation so as to wind used ribbon material onto the core as the ribbon is used. The core is intended to slide on and off of the spindle so that the core can be easily inserted onto and removed from the spindle. 
     A problem with existing core and spindle technology is that as the ribbon material is wound onto the core, the ribbon material compresses the core radially inward, causing the core to contract. As the core contracts, the interior surface of the core engages the exterior surface of the spindle with an increasing compression force. In effect, the core squeezes the spindle as the ribbon material is wound onto the core. When this occurs, removal of the core from the spindle is difficult if not impossible. Often times, the compression force is so great that the ribbon material must be unwound from the core, while the core is still disposed on the spindle, until the compression force is removed, at which point the core can be removed from the spindle. A similar problem can occur with supply rolls when new ribbon material is being wound onto a supply roll core disposed on a spindle. 
     Therefore, there is a need for improved core and spindle technology for ribbon materials that prevents the core from being squeezed onto the spindle as ribbon material is wound onto the core, thereby facilitating removal of the core from the spindle. 
     SUMMARY OF THE INVENTION 
     The invention provides improvements relating to core and spindle technology for use with ribbon materials. The invention has use in many environments in which a ribbon or sheet material is wound onto a core. In the preferred embodiment, the ribbon materials are those associated with printers and related equipment used to produce data bearing identity documents, including cards such as identification cards, drivers licenses, credit cards and the like, and booklets such as passports and the like. Examples of ribbon materials include printing ribbons, cleaning tape, index tape, labels, topping foil, and holographic overlay tape. The invention is beneficial for both ribbon take-up rolls in which used ribbon material is wound onto the core, as well as ribbon supply rolls in which new or unused ribbon material is wound onto the core. 
     In one aspect of the invention, a core for ribbon material is provided. The core comprises a hollow cylinder having a first open end and a second open end, an exterior surface and an interior surface, and a plurality of circumferentially spaced ribs connected to and extending inwardly from the interior surface. 
     In yet another aspect of the invention, a spindle for receiving a core thereon is provided. The spindle comprises a cylindrical member having a first exterior surface, and a plurality of ridge members extending outwardly from the first exterior surface. Each ridge member has sidewalls and an outer wall between the sidewalls. The outer walls of the ridge members define a second exterior surface, and the ridge members are spaced from each other so that facing sidewalls of adjacent ridge members define a channel between each adjacent ridge member. 
     In still another aspect of the invention, a combination of a core and spindle is provided. The core, which is to receive ribbon material thereon, includes a hollow cylinder having a first open end and a second open end, an exterior surface upon which ribbon material is to be wound, and an interior surface. In addition, a plurality of circumferentially spaced ribs are connected to and extend inwardly from the interior surface. The spindle, which is to receive the core thereon, includes a cylindrical member having a first exterior surface, and a plurality of ridge members extending outwardly from the first exterior surface. Each ridge member has sidewalls and an outer wall between the sidewalls. The outer walls of the ridge members define a second exterior surface, and the ridge members are spaced from each other so that facing sidewalls of adjacent ridge members define a channel between each adjacent ridge member. Further, the channels are sized to receive the ribs in close fitting relation, and, when the core is disposed on the spindle, a gap is provided between an inner edge of each rib and a base of each channel. 
     For a better understanding of the invention, its advantages and objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description, in which there is described a preferred embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a core and spindle according to the present invention. 
     FIG. 2 illustrates the core disposed on the spindle. 
     FIG. 3 is a top view of the core and spindle. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention relates to a core and spindle for use with ribbon material that prevents squeezing of the core onto the spindle as the ribbon material is wound onto the core. In the preferred embodiment, the core and spindle are used with ribbon materials that are used in the production of data bearing identity documents, including cards such as identification cards, drivers licenses, credit cards and the like, and booklets such as passports and the like. Examples of ribbon materials to which the invention applies includes, but is not limited to, mono-chromatic or multi-color printing ribbons, cleaning tape, index tape, labels, topping foil, and holographic overlay tape. The types of equipment that utilize these ribbon materials includes printers and laminators, as well as peripheral equipment utilized with printers and laminators. 
     The core and spindle of the present invention can form part of a take-up roll, in which use ribbon material is wound onto the core, or form part of a supply roll, in which new or fresh ribbon material is wound onto the core. 
     In order to describe the inventive concept, the invention will be described herein in relation to a core and spindle of a print ribbon take-up roll in a printer that is used in the production of data bearing identity documents. It is to be understood, however, that the invention is applicable to many other types of equipment that utilize a core and spindle. 
     FIG. 1 illustrates a core  10  and a spindle  12  for use in a printer. Used print ribbon  14 , illustrated in dashed lines, is wound onto the core  10  as the core  10  is rotated in the direction of the arrow by the spindle  12 . The core  10  thus acts as a take-up roll for the ribbon  14  as it is used up by an upstream printhead (not shown) of the printer. The print ribbon  14  is supplied by a supply roll (not shown) that is positioned upstream of the printhead. 
     The print ribbon  14 , which is illustrated in dashed lines in FIG. 1, preferably comprise a series of differently colored panels, such as cyan, yellow, magenta, and black. Alternatively, the print ribbon  14  comprises a single, solid color, i.e. monochromatic. The spindle  12  is mounted so as to be rotatably driven by a shaft  16  via a motor, such as a stepper motor (not shown), in known fashion. The core  10  is designed to interact with the spindle  12  such that as the spindle  12  is driven in rotation, the core  10  is simultaneously rotated with the spindle  12  whereby the print ribbon  14  is wound onto the core  10 . 
     With reference to FIGS. 1-3, the core  10  is seen to include a generally hollow cylinder  20  having a first open end  22  and a second open end  24 . The cylinder is preferably made from a plastic material. The cylinder  20  further includes an exterior surface  26  and an interior surface  28 . The exterior surface  26  of the cylinder  20  is preferably designed to enhance the effectiveness of the take-up of the used ribbon  14  onto the cylinder  20 . For example, the exterior surface  26  can be an increased friction surface, such as by providing a layer of high friction rubber material on the exterior surface  26 . Alternatively, the exterior surface  26  can be provided a slightly rough texture to increase the friction thereof. 
     A plurality of ribs  30   a-f  project radially inward from the interior surface  28  of the cylinder  20  toward the central axis of the cylinder. The ribs  30   a-f  are rectangular in shape and extend from adjacent the first end  22  to adjacent the second end  24 . As shown in FIG. 1, the ribs  30   a-f  stop short of the end  22  so that they are recessed relative to the end  22 . Similarly, the ribs  30   a-f  stop short of the end  24  so that they are recessed relative to the end  24 . The area between the ends of the ribs  30   a-f  and the ends  22 ,  24  provides space to allow insertion and seating of a radio frequency identification tag (not shown) completely within the cylinder  20  at one or both ends  22 ,  24  of the cylinder. A radio frequency identification tag suitable for use with the core  10  is described in U.S. patent application Ser. No. 10/308,244 filed on Dec. 2, 2002 entitled Radio Frequency Identification Tags On Consumable Items Used In Printers And Related Equipment. 
     As best seen in FIG. 3, the ribs  30   a-f  are arranged so that each rib is positioned diametrically opposite another rib. For example, rib  30   a  is diametrically opposite the rib  30   d , rib  30   b  is diametrically opposite rib  30   e , and rib  30   c  is diametrically opposite rib  30   f . Thus, the embodiment illustrated in FIGS. 1-3 includes three pairs of diametrically opposed ribs. However, it is to be realized that a larger or smaller number of ribs could be utilized. Further, when an odd number of ribs, for example three ribs, are used, the diametrically opposed positioning of the ribs cannot be used. 
     The ribs  30   a-f  each extend radially inward approximately the same distance to an inner edge  32 . The distance is selected so that when used ribbon  14  is wound onto the cylinder  20  and the cylinder is compressed, the inner edges  32  do not engage the surface  42  of the spindle  12  as will be described below. Likewise, in the non-compressed condition of the cylinder, shown in FIG. 3, the inner edges  32  do not engage the spindle surface  42 . 
     Returning to FIG. 1, the spindle  12  comprises a generally cylindrical small diameter member  40  defining a first exterior surface  42 , and a plurality of ridge members  44   a-f  extending outwardly from the first exterior surface  42 . The spindle  12  is preferably molded from a plastic material so that the member  40  and ridge members  44   a-f  are a one piece unit, with the spindle  12  being molded around the shaft  16  to connect the spindle to the shaft. 
     The respective lengths of the member  40  and ridge members  44   a-f  are greater than the distance between the ends  22 ,  24  of the cylinder  20  such that when the cylinder  20  is disposed on the spindle  12 , an end of the member  40  and the ends of the ridge members  44   a-f  extend beyond the end  22  of the cylinder  20 , as shown in FIG.  2 . 
     With particular reference to FIG. 1, the ridge members  44   a-f  will now be described. The ridge members  44   a-f  are identical to each other so only the ridge member  44   b  will be described in detail. The ridge member  44   b  comprises a pair of sidewalls  46  that are connected to and extend outwardly from the first exterior surface  42 , and an outer wall  48  between the sidewalls  46 . The sidewalls  46  and outer wall  48  extend adjacent to, but stop short of, the end  50  of the member  40  thereby leaving a cylindrical strip of the first exterior surface  42  adjacent the end  50 . Further, the ends of the sidewalls  46  adjacent the end  50  angle toward each other so that the ridge members  44   a-f  adjacent the end  50  are tapered, thereby forming angled guide surfaces  52 . In addition, a portion  54  of the outer wall  48  adjacent the guide surfaces  52  is slightly curved. The outer wall  48 , together with the outer walls of the other ridge members, defines a second exterior surface  56  (see FIG. 3) having a diameter greater than the diameter of the first exterior surface  42 . 
     As seen in FIGS. 1 and 3, the ridge members  44   a-f  are spaced from each other so that the facing sidewalls  46  of adjacent ridge members define a plurality of channels  58 . The number of channels  58  corresponds to the number of ribs  30   a-f , and the channels  58  are sized to receive the ribs  30   a-f  therein as shown in FIGS. 2 and 3. Stops  60  are provided at the ends of the channels  58  against which the ends of the ribs  30   a-f  abut when the cylinder  20  is fully disposed on the spindle  12 . The stops  60  thereby limit travel of the ribs  30   a-f  within the channels  58  and properly position the core  10  on the spindle  12 . Further, the base of each channel  58  is defined by the first exterior surface  42 . 
     The spacing between each facing sidewall  46  is only slightly greater than the width w of the ribs  30   a-f , so that the ribs  30   a-f  are received within the channels  58  with minimal play or spacing between the surfaces of the ribs and the sidewalls, as best seen in FIG.  3 . As a result, little relative movement is permitted between the core  10  and the spindle  12 . This will minimize the eccentricity and backlash between the spindle  12  and the core  10 . 
     To insert the core  10  onto the spindle  12 , the core  10  is simply slid onto the spindle  12 . The guide surfaces  52  of adjacent ridge members help guide the ribs  30   a-f  into the channels  58  so that precise alignment of the ribs and channels prior to sliding the core onto the spindle  12  is not necessary. When fully inserted onto the spindle  12 , the ends of the ribs  30   a-f  engage the stops  60 . 
     As illustrated in FIG. 3, when the core  10  is inserted onto the spindle  12 , the inner edges  32  of the ribs  30   a-f  are spaced from the first exterior surface  42  which defines the base of each channel  58 , thereby leaving a space  62  between each inner edge  32  and the first exterior surface  42 . The spaces  62  allow the core  10  to contract or compress radially when used ribbon  14  is wound onto the core  10 . The size of the spaces  62  is chosen so that, at the maximum anticipated extent of contraction of the core  10 , the inner edges  32  remain spaced from the first exterior surface  42 . Therefore, when the core  10  is contracted, there is no contact between the inner edges  32  and any exterior surface portion of the spindle  12 . As a result, as the core  10  is contracted radially by the ribbon  14 , the core is not squeezed onto the spindle  12 . When it comes time to remove the core from the spindle, the core slides off the spindle just as easily as it was slid onto the spindle. At the same time, the ribs  30   a-f  disposed within the channels  58  ensure that the core  10  can be rotated by and be positioned concentric to the spindle  12  as the spindle is rotatably driven. 
     FIG. 3 further illustrates the core  10  as including a plurality of projections  70  between adjacent pairs of the ribs  30   a-f . In the illustrated embodiment, three projections  70  are provided. However, a smaller number of projections, including a single projection, and a larger number of projections could be used. The projections  70  are disposed adjacent the end  24  of the cylinder  20  and extend only a short distance along the length of the core, as illustrated in dashed lines in FIG.  2 . The projections  70  extend radially inward from the interior surface  28  a distance that allows the core  10  to be slid onto the spindle  12 , and so that the inner edges of the projections are separated from the exterior surface  56  defined by the ridge members  44   a-f.    
     Attached to each projection  70 , and extending on either side thereof, are flaps  72 ,  74 , as evident from FIG.  3 . Preferably, the flaps  72 ,  74  are integrally formed with the projections  70 , although it is possible to form the flaps separately from the projections  70  and to secure the flaps to the projections using a suitable fastening mechanism, for example glue. The flaps  72 ,  74  have inner edges that, like the inner edges of the projections  70 , are sized so that they are spaced from the exterior surface  56  defined by the ridge members  44   a-f  when the core  10  is inserted onto the spindle  12 . The thickness of the flaps  72 ,  74  is less than the length of the projections  70 . In addition, the end surfaces of the ribs  30   a-f , the end surfaces of the projections  70  and the flaps  72 ,  74  lie in a single common plane. 
     The flaps  72 ,  74  provide surface area upon which data pertaining to the core  10  can be secured. For example, data identifying the supplier of the core  10  and/or ribbon material can be provided on the flaps. A variety of additional data can be stored on the flaps, including, but not limited to, data pertaining to ribbon type, what type(s) of machine the core  10  can be used with, manufacturing data, etc. The data is preferably written indicia provided on the flaps  72 ,  74 . 
     As described above, the inner edges of the projections  70  and flaps  72 ,  74  are spaced from the exterior surface  56  of the core  10 . The spacing is such that, when the core contracts, the projections  70  and flaps  72 ,  74  do not contact the exterior surface  56 . Therefore, removal of the core  10  from the spindle  12  is not hindered. It is to be realized, however, that the core  10  can be used without the projections  70  and flaps  72 ,  74  if desired. 
     The above specification, examples and date provide a complete description of the invention. Many embodiments of the invention, not explicitly described herein, can be made without departing from the spirit and scope of the invention.