Abstract:
A developer barrier sheet is positioned between a developer roller and a developer opening in a developer cartridge to reduce leaking of developer from the developer cartridge during shipping. The barrier sheet may be positioned into a developer cradle area before the developer roller is installed so that, upon installation of the developer roller, the barrier sheet is captured between the developer roller and various cartridge seals that surround the developer opening.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/008,138, filed Jun. 5, 2014, the entire contents of which are hereby incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    Developer cartridges for laser printers and copiers are replaceable components that supply developer or toner to the optical photoconductive drum (“OPC”) of a laser printer or copier. Developer cartridges generally include a housing for storing developer, a drive mechanism for receiving driving force from the printer or copier, and a series of rollers for transferring developer from the housing to the OPC. Developer cartridges are transported from manufacturing facilities throughout the world. One issue of concern for manufacturers of developer cartridges is the leaking of developer from the cartridge during transport. A variety of seals, blades, covers, and the like have been used in attempts to reduce the amount of developer that leaks from the cartridge during transport, but certain cartridge designs have remained prone to leaking during transport. 
       SUMMARY 
       [0003]    In some aspects, a developer cartridge includes a housing defining an elongated developer opening having a top edge and a bottom edge, a developer roller cradle adjacent the developer opening, and a pair of developer mounts on opposite ends of the developer opening. A developer roller is positioned in the developer roller cradle and rotatably supported by the developer mounts. A developer barrier is positioned between the developer roller and the developer roller cradle and covers the developer opening. The developer barrier contacts and wraps partially around the developer roller and includes a depending portion extending generally tangentially away from the developer roller cradle to facilitate removal of the developer barrier from between the developer roller and the developer roller cradle. 
         [0004]    A first seal may extend along a top edge of the developer opening and a second seal may extend along the bottom edge of the developer opening, and the developer barrier may directly engage the first and second seals. The first seal may include a doctor blade for regulating a thickness of a layer of developer on the developer roller during operation of the developer cartridge. A third seal may extend along one side of the developer opening and a fourth seal may extend along an opposite side of the developer opening. The developer barrier may directly engage the third and fourth seals. The housing may include a first concave semi-cylindrical surface on a first end of the developer opening, and a second concave semi-cylindrical surface on a second end of the developer opening opposite the first end. The developer barrier may directly engage the first concave semi-cylindrical surface and the second concave semi-cylindrical surface. The developer barrier may comprise a sheet of paper. The developer roller cradle may be at least partially defined by a first seal extending along the top edge of the developer opening and a second seal extending along the bottom edge of the developer opening. The developer barrier may directly contact the first and second seals. The developer barrier may be positioned directly between the developer roller and each of the first and second seals, and portions of the first and second seals that do not directly contact the developer roller with the developer barrier installed may directly contact the developer roller upon removal of the developer barrier. The first seal may comprise a doctor blade and the second seal may comprise a strip of polyester film (e.g., MYLAR, available from DuPont Teijin Films). 
         [0005]    In other aspects, a method of assembling a developer cartridge is provided. The developer cartridge includes a housing defining a developer opening and a developer roller cradle surrounding the opening. The method includes positioning a developer barrier sheet into the developer roller cradle to overlie the developer opening, and rotatably mounting a developer roller within the developer roller cradle to secure the developer barrier sheet between the developer roller and thOKe developer roller cradle. 
         [0006]    Rotatably mounting the developer roller within the developer roller cradle may include directly contacting the developer barrier sheet to both the developer roller and the developer roller cradle. Positioning the developer barrier sheet within the developer roller cradle may include positioning the developer barrier sheet against a first seal extending along a top edge of the developer opening and against a second seal extending along a bottom edge of the developer opening. Positioning the developer barrier sheet within the developer roller cradle may also or alternatively include positioning a depending portion of the developer barrier sheet to extend away from the developer roller cradle, and upon rotatably mounting the developer roller within the developer roller cradle, the depending portion may extend generally tangentially away from the developer roller cradle. 
         [0007]    In still other aspects, a method of remanufacturing a previously used developer cartridge is provided. The previously used developer cartridge includes a housing defining a developer opening and a developer roller cradle surrounding the developer opening. The developer cartridge further includes a developer roller rotatably positioned in the developer roller cradle. The method includes removing the developer roller from the developer roller cradle, cleaning at least a portion of housing, refilling the housing with developer, positioning a developer barrier sheet into the developer roller cradle to overlie the developer opening, and reinstalling the developer roller within the developer roller cradle to secure the developer barrier sheet between the developer roller and the developer roller cradle. 
         [0008]    Rotatably mounting the developer roller within the developer roller cradle may include directly contacting the developer barrier sheet to both the developer roller and the developer roller cradle. Positioning the developer barrier sheet within the developer roller cradle may include positioning the developer barrier sheet against a first seal extending along a top edge of the developer opening and against a second seal extending along a bottom edge of the developer opening. Positioning the developer barrier sheet within the developer roller cradle may include positioning a depending portion of the developer barrier sheet to extend away from the developer roller cradle, and upon reinstalling the developer roller within the developer roller cradle, the depending portion may extend generally tangentially away from the developer roller cradle. The housing may include a plurality of seals surrounding the developer opening, and the method may further include at least one of replacing and refurbishing at least one of the plurality of seals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a developer cartridge with a developer roller removed. 
           [0010]      FIG. 2  is a perspective view of the developer cartridge of  FIG. 1  with a developer barrier being positioned over a developer opening. 
           [0011]      FIG. 3  is a perspective view of the developer cartridge of  FIG. 1  with the developer roller being positioned in the developer opening while the developer barrier is in place. 
           [0012]      FIG. 4  is a side perspective view of the developer cartridge of  FIG. 1  with a shipping protector being installed over the developer roller. 
           [0013]      FIG. 5  is a perspective view of the developer cartridge of  FIG. 1  with the shipping protector in place and a securing member securing the developer barrier to the shipping protector. 
           [0014]      FIG. 6  is a perspective view of the developer cartridge of  FIG. 1  showing a user removing the developer barrier. 
       
    
    
       [0015]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
         [0016]    Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
       DETAILED DESCRIPTION 
       [0017]      FIG. 1  illustrates a partially assembled developer cartridge  10 . The cartridge  10  includes a housing  14  defining a developer opening  18 . The developer opening  18  is generally rectangular and includes a top edge  22 , a bottom edge  26 , and two side edges  30 ,  34 . A first seal  38  extends along the top edge  22 , and a second seal  42  extends along the bottom edge. Third and fourth seals  46 ,  50 , which may be in the form of side seals, extend along respective side edges  30 ,  34 . The first seal  38 , second seal  42 , third seal  46 , and fourth seals  50  generally may be comprised of foam, felt, or other suitable sealing materials. In some embodiments, including the illustrated embodiment, the first seal  38  may be or include a doctor blade, and the second seal  42  may be or include a polyester film strip. Each of the third and fourth seals  46 ,  50  defines a concaved, substantially semi-cylindrical surface  54 . The first seal  38 , the second seal  42 , and the semi-cylindrical surfaces  54  cooperate to define a developer roller cradle  58  that generally surrounds and is adjacent to the developer opening  18 . In some embodiments, the top edge  22 , bottom edge  26  and two side edges  30 ,  34  of the developer opening  18  may be defined by the first seal  38 , the second seal  42 , and the semi-cylindrical surfaces  54 , respectively. The housing  14  also defines a pair of opposed developer roller mounts  62  configured to support a developer roller  64  ( FIGS. 3-4 ) for rotation about an axis. The mounts  62  may directly or indirectly support the developer roller  64  alone or in combination with other components of the developer cartridge 
         [0018]      FIG. 2  illustrates a developer barrier sheet  66  being positioned to cover the developer opening  18 . The developer barrier sheet  66  of the illustrated embodiment is a generally rectangular sheet having a width that substantially corresponds to a distance between the developer roller mounts  62 . In this regard, the developer roller barrier sheet  66  is sized to extend width-wise between the two semi-cylindrical surfaces  54  and to at least partially cover the two semi-cylindrical surfaces  54 . In the cross-wise direction, the developer roller barrier sheet  66  is sized to extend along and substantially cover the developer opening  18  and at least portions of the first seal  38  and the second seal  42 . The barrier sheet  66  is further sized to include a depending portion  70  that extends in a generally tangential direction away from the developer roller cradle  58  and facilitates removal of the barrier sheet  66  from the cartridge  10 , as discussed below. In some embodiments, including the illustrated embodiment, the housing  14  may include an overhanging portion  78  positioned adjacent to the developer roller cradle  58  and a leading edge  74  of the developer barrier sheet  66  may be abutted against the overhanging portion  78  to properly locate the developer barrier sheet  66  with respect to the developer opening  18 . The specific size of the developer barrier sheet  66  depends upon the size of the developer cartridge  10  in which it is used. In general, the portion of the developer barrier sheet  66  that extends between the second seal  42 , the first seal  38 , and the surfaces  54  will be generally rectangular. The depending portion  70  of the developer barrier sheet  66  may be rectangular, as shown, or may be substantially triangular or some other shape that may allow for a reduction in material use. The barrier sheet  66  may be or include a sheet of paper, polymer film, woven material, other suitable web-like materials, and combinations thereof. 
         [0019]    With the developer barrier sheet  66  positioned in the developer roller cradle  58 , the developer roller  64  may be mounted to the developer roller mounts  62 , as shown in  FIG. 3 . Although specifics can vary depending on the construction of a specific developer cartridge  10 , installation of the developer roller  64  typically involves positioning one end of the developer roller  64 , which may include a bearing, bushing, or similar structure, into one of the developer roller mounts  62 , and then positioning the other end of the developer roller  64 , which may also include a bearing, bushing, or similar structure, into the other of the developer roller mounts  62 . As the developer roller  64  is installed, the developer barrier sheet  66  is captured between the developer roller  64  and the first seal  38 , second seal  42 , and semi-cylindrical surfaces  54 . When the developer roller  64  is fully installed, the barrier sheet  66  directly engages the first seal  38 , second seal  42 , and semi-cylindrical surfaces  54 , is wrapped around a portion of the circumference of the developer roller  64 , and overlies the developer opening  18 . In this regard the barrier sheet  66  is positioned and held snugly between the developer roller  64  and the first seal  38 , second seal  42 , and semi-cylindrical surfaces  54 . The presence of the barrier sheet  66  reduces leakage of developer from the cartridge  10  during transportation. As shown in  FIG. 4 , a shipping protector  82  may be installed to cover and protect the exposed surfaces of the developer roller  64  during transport. As shown in  FIG. 5 , the depending portion  70  of the developer barrier sheet  66  may then be secured to the shipping protector  82 , for example using a piece of tape  86 . 
         [0020]    Referring to  FIG. 6 , when a user receives the cartridge  10 , the user may use the piece of tape  86 , if present, or the depending portion  70  to withdraw the developer barrier sheet  66  from between the developer roller  64  and the developer opening  18 . When the developer barrier sheet  66  is removed, the developer roller  64  is brought into direct contact with the first seal  38 , the second seal  42 , and the semi-cylindrical side surfaces  54 , and the developer opening  18  becomes unobstructed such that developer may move through the developer opening  18  and onto the developer roller  64  for printing operations. In this way, portions of the first seal  38 , second seal  42  and semi-cylindrical side surfaces  54  that did not directly contact the developer roller with the barrier sheet  66  installed are brought into direct contact with the developer roller when the barrier sheet  66  is removed. 
         [0021]    While the developer barrier sheet  66  and method described above can be used to improve the sealing characteristics of many developer cartridges, the developer barrier sheet  66  is particularly well suited for use in remanufactured developer cartridges in which one or more of the doctor blade  38 , polyester film strip  42 , and side seals  46 ,  50  may be somewhat worn from an initial cartridge life-cycle. In such cases, one or more of the first seal or doctor blade  38 , second seal or polyester film strip  42 , and third and fourth or side seals  46 ,  50  may be adequate for preventing leakage of developer during operation of the cartridge, but may be inadequate for preventing leakage of developer during transportation of the cartridge. Accordingly, in some aspects, a method of remanufacturing a developer cartridge may include removing the developer roller  64  from the developer roller mounts  62 , cleaning the cartridge  10 , replacing and/or refurbishing one or more of the first  38 , second  42 , third  46 , or fourth seals  50  (for example the doctor blade  38 , polyester film strip  42 , and side seals  46 ,  50 ), refilling the housing  14  with toner, positioning the developer barrier sheet  66  in the developer roller cradle  58  to overlie the developer opening  18 , and reinstalling the developer roller  64 , which may be or include a new, replacement developer roller  64 , into the developer roller mounts  62 , thereby capturing the developer barrier sheet  66  between the developer roller  64  and the first, second, third, and fourth seals  38 ,  42 ,  46 , and  50 . 
         [0022]    While specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the disclosure, and the scope of protection is to be commensurate with the scope of the accompanying claims.