Patent Document

BACKGROUND OF THE INVENTION  
       [0001]     Embodiments of the present invention generally relate to a cover for a thermal transfer printer, and more particularly to a cover that protects against moisture infiltration when the thermal transfer printer is being cleaned.  
         [0002]     A typical thermal transfer printer system is fully programmable and capable of delivering variable information with every print. The system uses a high resolution print head in order to print characters varying from simple text to complex logos and a range of industrial bar codes. Each printer system uses thermal transfer technology that allows an operator to print directly on packaging material, instead of using separate labels.  
         [0003]     Thermal transfer printers are used in various industries, such as the food packaging industry. For example, thermal transfer printers are used to print information on flexible packaging used in the snack food industry.  
         [0004]     A typical packaging line includes various support structure and components in addition to a thermal transfer printer system. The support structures and components are periodically washed, such as through power washing, in order to maintain the efficiency and integrity of the packaging line and process.  
         [0005]     During a wash process, a thermal transfer printer is typically removed from a production line, or a plastic sheet is placed over the printer. Often, the printer is located in a position that is not conveniently accessible. As such, it may prove difficult to cover the printer in such a manner.  
         [0006]     Thus, a need exists for an efficient system and method of protecting a thermal transfer printer during a washing process. Further, a need exists for a system and method of quickly and easily covering and uncovering the printer.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     Embodiments of the present invention provide a thermal transfer printing system including a printer housing, a platen member, a first covering portion, or hood, and a second covering portion, or front cover. The printer housing includes a printhead, print media, and an opening, wherein the printhead is configured to urge the print media through the opening during a printing process.  
         [0008]     The platen member is positioned proximate the opening, and a substrate gap is defined between the platen member and the opening. A substrate, such as film, paper, cloth, or the like, is passed through the substrate gap and is sandwiched between the print media and the platen member when the printhead urges the print media through the opening during a printing process.  
         [0009]     The hood is affixed to the printer housing, and the front cover is removably secured to the hood. The printer housing is completely covered by the first and second covering portions. At least one of the hood and the front cover includes at least one seal member that forms a fluid-tight seal between the hood and the front cover when the front cover is secured to the hood. A gasket may be interposed between the hood and the printer housing. The hood and front cover may be formed of stainless steel, plastic, rubber, glass, plexiglass, or various other materials that are substantially impermeable to fluid, or otherwise prevent moisture from passing therethrough.  
         [0010]     The system may also include a pivoting or sliding bracket operatively connected to the platen member, which may be a platen roller or plate. The pivoting or sliding bracket is configured to move the platen member away from the printer housing.  
         [0011]     Embodiments of the present invention also provide a method of protecting a printer housing against moisture infiltration. The method includes affixing a fixed covering portion over the printer housing. The affixing step includes exposing a printing opening of the printer housing. The method also includes securing a removable covering portion to the fixed covering portion, wherein the removable covering portion covers the printing opening. The securing step includes providing a sealing engagement between the fixed and removable covering portions. Further, the securing may include snapably, threadably or latchably securing the removable covering portion to the fixed covering portion.  
         [0012]     The method also includes completely covering the printer housing when the removable covering portion is secured to the fixed covering portion. The method may also include providing a sealing member between the fixed covering portion and the printer housing.  
     
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS  
       [0013]      FIG. 1  illustrates an isometric view of a thermal transfer printer system, according to an embodiment of the present invention.  
         [0014]      FIG. 2  illustrates a schematic representation of a thermal transfer printer system, according to an embodiment of the present invention.  
         [0015]      FIG. 3  illustrates a schematic representation of a thermal transfer printer system, according to an alternative embodiment of the present invention.  
         [0016]      FIG. 4  illustrates an isometric partial exploded view of a thermal transfer printer system, according to an embodiment of the present invention.  
         [0017]      FIG. 5  illustrates an isometric view of a printer housing cover, according to an alternative embodiment of the present invention  
         [0018]      FIG. 6  illustrates a side view of a thermal transfer printer system according to an embodiment of the present invention. 
     
    
       [0019]     The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0020]      FIG. 1  illustrates an isometric view of a thermal transfer printer system  10 , according to an embodiment of the present invention. The system  10  includes a printer housing  12  and a substrate delivery and support structure  14  including a series of substrate support shafts  16  connected to a support bracket  18 . The bracket  18  may also support the printer housing  12 . Some or all of the substrate support shafts  16  may be rotatable. A printing substrate, such as paper, cloth, web material, foil  20 , or the like, is passed through, and supported by, the shafts  16 . The foil  20  passes through a gap  22  that is defined between the printer housing  12  and a platen support  24 . In order to print characters on the foil  20 , the platen support  24  may be urged toward the printer housing  12 , and a high temperature print head (not shown in  FIG. 1 ) is urged toward the plate support  24 , thereby sandwiching the passing foil  20  therebetween. The high temperature print head then transfers print media from a ribbon (not shown in  FIG. 1 ) to the foil  20 . Once the desired characters are printed on the foil  20 , the foil  20  passes out of the gap  22 . In general, the foil  20  may be continuously passed through the gap  22  at a constant or variable rate.  
         [0021]      FIG. 2  illustrates a schematic representation of the thermal transfer printer system  10 . The printer housing  12  includes a series of rollers  26  that support a print ribbon  28 . The ribbon  28  passes between a print head  30  and an opening  32  of the printer housing  12 . A mark sensor  34  is operatively connected to the printer housing  12  and is configured to detect printing cues located on the foil  20 .  
         [0022]     The foil  20  is continually passed through the gap  22  in the direction of arrow A. That is, the foil  20  does not cease moving during printing. The shafts  16  may rotate in the direction of arrows B in order to assist the movement of the foil  20  through the gap  22 . Optionally, the shafts  16  may be fixed.  
         [0023]     As the foil  20  moves in the direction of arrow A, the mark sensor  34  detects printing cues on the foil  20 . The mark sensor  34  then sends a signal to a processing unit  36 . The processing unit  36  may alternatively be remotely located from the printer housing  12 . The processing unit  36  then activates the print head  30  at an appropriate time based on the data received from the mark sensor  34 .  
         [0024]     In order to print characters on the foil  20  as it passes through the gap  22 , the print head  30  is moved through the opening  32  toward a platen roller  40  in the direction of arrow C, while the platen roller  40  may or may not be urged toward the print head  30  in the direction of arrow D. The print head  30  and the platen roller  40  sandwich the moving foil  20  and the ribbon  28  therebetween. The ribbon  28  moves along with, or optionally in opposition to, the foil  20  in the direction of arrow A as the print head  30  engages the ribbon  28 , which is indexed by the rollers  26 . The platen roller  40  rotates in the direction of arrow E as the foil  20  and ribbon  28  are sandwiched between the print head  30  and the platen roller  40 , and the high temperature print head  30  transfers print media from the ribbon onto the foil  20 .  
         [0025]      FIG. 3  illustrates a schematic representation of the thermal transfer printer system  10 , according to an alternative embodiment of the present invention. In this embodiment, the foil  20  is passed through the gap  22  in the direction of arrow A. However, during printing, the movement of the foil  20  is stopped. The print head  42  is then moved toward the fixed platen pad  44  in the direction of arrow C, and in the process, urges the ribbon  28  and the foil  20  into the platen pad  44 . The print head  42  is then moved in the direction of arrow F as it continues to print characters on the foil  20 . Once the printing process is complete, the print head  42  is moved away from the platen pad  44  in the direction of arrow D, and is also moved back to a home position in the direction of arrow A. The foil  20  then moves through the gap in the direction of arrow A.  
         [0026]      FIG. 4  illustrates an isometric partial exploded view of the thermal transfer printer system  10 . Various support and print shown in  FIGS. 1-3  structures (e.g., the rollers and the platen roller) are not shown in  FIG. 4  for the sake of clarity. The system  10  includes the printer housing  12  positioned within a hood  46  and a removable front cover  48 . The hood  46  and the front cover  48  may be formed of stainless steel, plastic, rubber, plexiglass or various other materials that prevent fluid from passing therethrough.  
         [0027]     The hood  46  includes an upper surface  47 , integrally formed with lateral walls  49 , and a rear wall  51 , defining a printer housing chamber  57  therebetween. A cable conduit  59  extends outwardly from the rear wall  51 , and provides a fluid-tight path for cabling and wiring (not shown) of the printer housing  12  to pass. The front cover  48  includes a front face plate  53  integrally formed with a base member  55 . A seal member  61  extends around the inner periphery of the front face plate  53  and the base member  55 . The front cover  48  is configured to sealingly secure to the hood  46 , thereby providing a fluid-tight barrier between the printer housing  12  and an outside environment. That is, the secure sealing engagement between the front cover  48  and the hood  46  prevents fluid from infiltrating into the printer housing chamber  57 .  
         [0028]     A gasket  50 , formed of neoprene, rubber, or otherwise elastomeric material, is positioned on a top surface  52  of the printer housing  12 . Fastener through holes  54  are formed through the gasket  52  and are aligned with fastener receptacles  56  formed through the upper surface  52  of the printer housing  12 . The hood  46  also includes fastener through holes  58  formed through the upper surface  47 . The hood  46  is positioned over the printer housing  12  so that the fastener through holes  58  are aligned with the fastener through holes  54  of the gasket  50  and the fastener receptacles  56  of the printer housing  12 .  
         [0029]     The hood  46  is mounted to a mounting bracket  60  having fastener through holes  62  that are aligned with the fastener through holes  58 . Fasteners  64  pass through the fastener through holes  58 ,  54  and are securely retained within the fastener receptacles  56  of the printer housing  12 . Thus, the hood  46  is secured to the mounting bracket  60 , which is secured to a support structure (not shown), and the printer housing  12 , with the gasket being sealingly sandwiched between the hood  46  and the top surface  52  of the printer housing  12 . The gasket  50  prevents moisture infiltration through the through holes  58  of the hood  46 .  
         [0030]     Optionally, the hood  46  may be fastened to the mounting bracket  60  and/or the printer housing  12  in a variety of other ways. For example, the hood  46  may be bonded, or welded to the mounting bracket  60  and/or the printer housing  12 . Alternatively, the hood  46  may snapably, latchably, or otherwise securely engage the printer housing  12  and/or the mounting bracket  60 .  
         [0031]     During a printing operation, the front cover  48  is removed from the hood  46  in order to allow access to the printer housing  12 . As such, the front face  66  and the underside  68 , which is proximate the gap  22  shown in  FIGS. 2 and 3 , are exposed.  
         [0032]     When the system  10  is to be washed, the front cover  48  is sealingly secured to the hood  46 . The face plate  53  of the front cover  48  sealingly engages the front edges of the upper surface  47  and lateral walls  49  of the hood  46 , while the base member  55  sealingly engages the lower edges of the lateral and rear walls  49  and  51 . The front cover  48  may snapably, latchably, or otherwise removably and sealingly engage the hood  46  to provide protection against moisture infiltration.  
         [0033]     The hood  46  is configured to remain fixed to the printer housing  12 , as discussed above, while the front cover  48  is configured to be removed from the hood  46  during a printing operation. Thus, the hood  46  remains permanently fixed to the printer housing  12  during printing and washing processes.  
         [0034]     Alternatively, the front cover  48  may include the lateral walls  49 , instead of the lateral walls  49  being integrally formed with the hood  46 . Further, instead of including a rigid front cover  48 , a retractable, flexible elastomeric or neoprene sheet may be included with the hood. The sheet or film may be rolled into open and closed positions with respect to the hood.  
         [0035]      FIG. 5  illustrates an isometric view of a printer housing cover  70 , according to an alternative embodiment of the present invention. The cover  70  includes a top surface  72  integrally formed with lateral walls  74  and a rear wall  76 , defining a printer housing chamber  78  therebetween. A retractable, flexible, fluid-proof covering member  80  is positioned underneath the top surface  72 . The covering member  80  may be formed of flexible rubber, plastic, neoprene, or otherwise elastomeric material. Lateral edges  82  of the covering member  80  may slidably and sealingly secure to guide tracks  84  positioned on interior surfaces  86  of the lateral walls  74 . The covering member  80  may be rolled onto a roller (not shown) positioned underneath the top wall  72 .  
         [0036]     In order to close the printer housing cover  70 , the covering member  80  is pulled downward in the direction of arrow F, and is moved over the guide tracks until it engages an interior surface of the rear wall  76 . The edge  88  of the covering member  80  may include a latch, snap, clasp, or the like configured to engage a reciprocal structure positioned on the interior surface of the rear wall  76 . Thus, the printer housing cover  70  may be sealingly closed.  
         [0037]     The covering member  80  may be manually moved over the guide tracks  84 . Optionally, a motor (not shown) may be operatively connected to the covering member  80 , such as through a roller support, in order to automatically open and close the printer housing cover  70 .  
         [0038]      FIG. 6  illustrates a side view of the thermal transfer printer system  10 . The platen roller  40  may be operatively connected to a pivoting bracket  90  that allows the platen roller  40  to be moved over a range of motion shown by angle α. The platen roller  40  is pivoted by way of the pivoting bracket  90  in order to allow a larger clearance area for the front cover  48  to be sealingly secured to the hood  46 . The platen roller  40  may be manually pivoted, or the pivoting bracket  90  may optionally be operatively connected to an actuator, which is configured to automatically pivot the platen roller  40 .  
         [0039]     Embodiments of the present invention provide an efficient system of protecting a printer housing from moisture infiltration during a washing process. Embodiments of the present invention also provide a system and method that allow a user to quickly and easily sealingly cover and uncover the printer housing.  
         [0040]     While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Technology Category: 5