Abstract:
A device for driving a pin that fastens a printer cartridge drum to a printer cartridge at least on one end of the printer cartridge drum, the device comprising a device body defining a device body recess and a shaft configured to be inserted in the device body recess and to be moved within the device body recess, wherein the movement of the shaft within the device body recess is configured to drive the pin and alter the attachment of the printer cartridge to the printer cartridge at the at least one end of the printer cartridge drum.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     None 
     FIELD OF THE INVENTION 
     The present invention relates to electrophotography, particularly methods and apparatus for remanufacturing toner cartridges. 
     BACKGROUND 
     Used printer cartridges of fax machines, copiers, inkjet printers, and laser printers are often remanufactured. Printer cartridges typically include a toner hopper, a waste hopper, primary charge roller or PCR, a developer roller, and a drum. Generally, printers embed toner on paper by relying on electrical charges occurring within the printer cartridges. The toner is typically stored in the toner hopper and carries a negative charge. The drum is typically given a charge by the PCR. The charge of the drum is typically more positive than the charge of the toner, and thus the drum is able to attract the toner. Once the drum is given a charge by the PCR and a print pattern is set, the drum gets coated with toner. The drum that is coated with toner then rolls over a sheet of paper, which is usually given a negative charge by the PCR. The charge of the paper is less negative than the charge of the toner, and thus the paper attracts the toner. The toner is embedded on the paper according to the print pattern. 
     The drum is usually one of the components that wears out from usage and gets replaced during remanufacturing. The drum is typically attached to a drum axle, which is attached to a motor of the printer and allows the motor to rotate the drum. In some cartridges, the drum is attached to the drum axle with a mechanical spring pin that is inserted through a portion of the drum and a portion of the drum axle. Examples of these cartridges include cartridges for Hewlett-Packard laser printer model numbers 3000, 3500, 3600, 3700, and 3800. 
     To detach the drums from the drum axles of the above cartridges, a hammer and a chisel is conventionally used. The chisel is first aligned with the mechanical spring pin. Once the chisel is aligned, a hammer is used to cause the chisel to drive the mechanical spring pin out of the drum and the drum axle thereby allowing the drum to be detached from the cartridge. Other methods of detaching the drums include using a punch in lieu of the chisel. The punch may include a flatter head than the chisel, which provides a wider surface of pin contact than the chisel. Consequently, the punch may more effectively contact and drive the mechanical spring pin out of the drum and the drum axle than the chisel. 
     At least one problem with the conventional methods and tools is that they expose the drum to being damaged. For instance, the drum may include drum hubs made of soft plastic. Since irregular force is applied to the drum hub by the hammer, the chisel, or the punch, the soft plastic of the drum hub may be deformed. Another problem with the conventional tools is that they do not ease the step of aligning the mechanical spring pin with the device used to drive the mechanical spring pin out of the drum and the drum axle. The chisel or the punch may contact the mechanical spring pin, but may easily slip from the mechanical spring pin. Yet another problem with the conventional tools is that they only provide leverage in detaching the drum from the cartridge. The conventional tools do not provide leverage when a drum needs to be attached to the cartridge. Thus, the conventional methods and tools may not be desirable in high volume cartridge remanufacturing environments. Methods and apparatus for efficiently and quickly detaching the drums from the cartridges and reattaching the same are desired and are addressed by the present invention. 
     BRIEF DESCRIPTION 
     A device for driving a pin that fastens a printer cartridge drum to a printer cartridge at least on one end of the printer cartridge drum, the device comprising a device body defining a device body recess and a shaft configured to be inserted in the device body recess and to be moved within the device body recess, wherein the movement of the shaft within the device body recess is configured to drive the pin and alter the attachment of the printer cartridge to the printer cartridge at the at least one end of the printer cartridge drum. 
     The above description sets forth, rather broadly, a summary of embodiments of the present invention so that the detailed description that follows may be better understood and contributions of the present invention to the art may be better appreciated. Some of the embodiments of the present invention may not include all of the features or characteristics listed in the above summary. There may be, of course, other features of the invention that will be described below and may form the subject matter of claims. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and to the arrangement of the components set forth in the following description or as illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is substantially a front elevational view of an embodiment of a pin driver of the present invention. 
         FIG. 2  is substantially a front elevational view of an embodiment of an engagement pin of the present invention. 
         FIG. 3  is substantially a front elevational view of an embodiment of an alignment pin of the present invention. 
         FIG. 4  is substantially a top plan view of a prior art cartridge for which the various embodiments of the pin driver of the present invention may be used. 
         FIG. 5  is substantially a front elevational view of the portion of the cartridge in  FIG. 4  that includes the drum and the drum axle. 
         FIG. 6  is substantially a rear elevational view of the same cartridge portion as in  FIG. 5 . 
         FIG. 7  is substantially a perspective view of the same cartridge portion as in  FIG. 5  with a pin attaching the drum to the drum axle. 
         FIG. 8  is substantially a perspective view similar to  FIG. 7 , but with the pin driver embodiment shown in  FIG. 1  being used. 
         FIG. 9  is substantially a schematic view of an end of the pin driver and a portion of a drum hub to which the pin driver end may be configured to abut. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part of this application. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     The present invention comprises a pin driver and related methods of use. Referring to  FIG. 1 , the pin driver  20  may include a tool body  22 , a shaft  24 , an engagement pin  26 , and an alignment pin  28 . The tool body  22  may have a C-shape structure, which defines a first end  30  and a second end  32 . The first end  30  is preferably positioned at the bottom of the C-shape structure and preferably defines a first recess (not shown) proximate to the tip of the first end  30 . The first recess is preferably configured to accommodate the shaft  24 , which may be moved within the first recess. It can be appreciated that the first end portion  30  supports, at least partially, the movable shaft  24 . Thus, the first end  30  of the tool body  22  may be thicker than the second end  32  to provide structural integrity to the first end portion  30 . 
     The shaft  24  preferably includes continuous projecting helical ribs or male threads. The wall  34  that surrounds the first recess preferably includes corresponding set of female threads. The shaft  24  may be turned and moved within the first recess using a handle  36  attached to a first shaft end  38 . It can be appreciated that the turning of the shaft  24  either elongates or shortens the length of the shaft  24 , as measured from the first end  30  of the tool body  22 . It can further be appreciated that the turning of the shaft  24  moves the tool body  22  up and down the shaft  24 . 
     The shaft  24  preferably also includes a second shaft end  40 , which is opposite the first shaft end  38  where the handle  36  is positioned. An engagement pin  26  is preferably attached to the second shaft end  40 . The engagement pin  26  may be another shaft with a smaller diameter than the shaft  24  and may include an edge that tapers towards the tip. The edge may further include a substantially flat surface that is perpendicular to the engagement pin shaft. As the engagement pin  26  is attached to the shaft  24 , the rotation of the shaft  24  also rotates the engagement pin  26 . The engagement pin  26  is preferably configured to push a mechanical spring pin to detach a drum from a drum axle, as described below. 
     With continued reference to  FIG. 1 , the second end  32  of the pin driver  20  is preferably opposite the first end  30  of the C-shape structure of the tool body  22 . In  FIG. 1 , the first end  30  is positioned on the bottom of the tool body  22 , and thus the second end  32  is positioned on top of the tool body  22 . The second end  32  preferably defines a second end recess  42  (shown in  FIG. 9 ). The second end recess is preferably configured to accommodate the insertion of the alignment pin  28 . 
     The alignment pin  28  is preferably tied to the shaft  24  using a tie  44  known in the art. It is noted that the alignment pin  28  is only optionally tied to the shaft  24  to ensure that the alignment pin  28  is not misplaced or lost and to provide an alignment pin  28  that can easily be grasped when needed. The alignment pin  28  need not be tied to the shaft  24 . The alignment pin  28  may also be attached elsewhere around the pin driver  20  using methods known in the art. 
     Referring now to  FIG. 2 , the structure of the engagement pin  26  is shown in detail wherein the engagement pin  26  preferably includes an engagement pin shaft  46  directly attached to the shaft  24 . The engagement pin shaft  46  preferably has a smaller diameter than the shaft  24 . The engagement pin  26  preferably also includes a pin contact portion  48 , which is preferably attached to the end of the engagement pin shaft  46  that is opposite to the end where the shaft  24  is attached. The pin contact portion  48  preferably includes a structure that tapers from the engagement pin shaft  46  to its tip. The pin contact portion  48  is preferably sized to fit inside a recess defined by the mechanical spring pin to be removed by the pin driver  20  (not shown). 
     Referring now to  FIG. 3 , the structure of the alignment pin  28  is shown in detail. The alignment pin  28  preferably includes an alignment pin head  49 . The alignment pin head  49  may be cylindrical in shape and may define a pin head recess  51  to accommodate a tie  44 , which may be used to attach the alignment pin  28  to the pin driver  20 . An alignment pin shaft  53  is preferably attached to the alignment pin head  49 . The alignment pin shaft  53  preferably has a smaller diameter than the alignment pin head  49 . The alignment pin  28  preferably also includes an alignment pin contact portion  55  attached to the alignment pin shaft  53 . The alignment pin contact portion  55  preferably includes a cylindrical body and an edge that tapers toward the tip and forms a pointed edge  57 . It is noted that in other embodiments of the pin driver, the alignment pin head  49  may not include the pin head recess  51 . The alignment pin shaft  53  and the cylindrical body of the alignment pin contact portion  55  may be integrated and may have uniform diameter. 
     The present invention also includes methods relating to the use of the pin driver  20 . Before describing one of the methods, the order in which the steps are presented below is not limited to any particular order and does not necessarily imply that they have to be performed in the order presented. It will be understood by those of ordinary skill in the art that the order of these steps can be rearranged and performed in any suitable manner. It will further be understood by those of ordinary skill in the art that some steps may be omitted or added and still fall within the spirit of the invention. 
     The cartridge to be remanufactured is preferably disassembled such that the drum can be accessed. In the description below, the drawings corresponding to the description depict cartridges from original equipment manufacturers (OEMs), including Hewlett Packard company&#39;s HP3700, HP 3500, HP 3800, HP 3600, and HP 3000 cartridges. It is noted that the application of the invention is not limited to Hewlett Packard cartridges. The invention may be used with cartridges from various manufacturers. 
     Drum Disassembly 
     Referring now to  FIG. 4 , a drum  50  typically has a first end  54  and a second end  56 . The first end  54  is typically attached to a first cartridge portion  58  of the cartridge  52 . The second end  56  is typically attached to a drum axle  60 . The drum axle  60  is typically a piece of shaft that connects the drum  50  to a motor of a printer to allow the motor to rotate the drum. The drum axle is typically attached to a second cartridge portion  62 . 
     With reference now to  FIGS. 5 and 6 , the first end  54  of the drum  50  may include a drum hub  64 . The drum hub  64  may define a pair of opposing recesses, which may be a circular recess  66  on one end ( FIG. 5 ) and a square recess  68  on the other end ( FIG. 6 ). The drum hub  64  may be attached to a drum axle  60 , which may define a drum axle recess. The drum axle recess may be aligned with the pair of opposing recesses  66  and  68  of the drum hub to form a pin passage  70 . A drum spring pin  72  is typically inserted through the pin passage  70  to attach the drum  50  to the drum axle  60  ( FIG. 7 ). The drum spring pin  72  may be hollow, and each drum spring pin end may define a corresponding drum spring pin recesses  73  and  75 . The drum axle  60  may be attached to the second cartridge portion  62 . Thus, the second end  56  of the drum  50  is indirectly attached to the cartridge via the drum axle  60 . 
     Referring now to  FIG. 8 , once the cartridge has been disassembled to provide access to the drum  50 , the pin driver  20  is preferably positioned around the drum  50  such that the C-shaped tool body  22  is over the drum hub  64 . The drum hub  64  is preferably positioned in between the first end  30  and the second end  32  of the tool body  22 . If the drum hub  64  is of the type that includes a circular recess on one end and a square recess on another, the drum  50  is preferably rotated such that the first end  30  of the tool body  22  is facing the circular recess. The alignment pin  28  may be inserted through the second recess  42  defined by the second end  32 . The shaft  24  may be rotated, and the engagement pin  26  may be aligned with the drum spring pin  72  to be removed. Once the shaft  24  has been extended such that the engagement pin  26  contacts the drum spring pin  72 , the pin contact portion  48  of the engagement pin  26  may then be inserted into the recess  73  of the drum spring pin  72 . 
     The shaft  24  may be rotated until the second end  32  of the tool body  22  abuts the drum hub  64  ( FIG. 9 ). The drum hub  64  may include an indented sub-structure  65 , which defines the recess  67  for the drum spring pin  72 . The second end  32  of the tool body  22  may include a protruding portion  43  designed to fit within the indented sub-structure  65  of the drum hub. Once the protruding portion  43  of the second end  32  abuts the indented sub-structure  65  of the drum hub, the shaft  24  may be rotated until the alignment pin  28  is withdrawn from the second recess  42  and the drum spring pin  72  is detached from the drum hub. A portion of the engagement pin may have to be inserted through the pin passage to drive the drum spring pin  72  out of the drum hub. It can be appreciated that the protruding portion  43  aids in providing a much precise alignment between the second recess  42  and the pin recess  67 . The precise alignment may minimize the exposure of the drum spring pin from being damaged. 
     Drum Re-Assembly 
     Unlike the conventional methods described above, the pin driver  20  may provide leverage during both disassembly and re-assembly. To use the pin driver  20  during re-assembly, the pin driver  20  may be positioned around the drum  50  such that the C-shaped tool body  22  is over the drum hub  64 . The drum hub  64  is preferably positioned in between the first end  30  and the second end  32  of the tool body  22 . If the drum hub  64  is of the type that includes a circular recess on one end and a square recess on another, the drum  50  is preferably rotated such that the first end  30  of the tool body  22  is facing the square recess. The drum spring pin  72  is preferably inserted through the square recess. If the drum hub  64  does not have two types of recesses, then the drum spring pin  72  may be inserted through any drum hub recess. 
     The second end  32  may be positioned to abut the drum hub  64 , and the alignment pin  28  may be inserted through the second recess  42  of the second end  32 . A portion of the alignment pin  28  may be inserted through the pin passage  70  defined by the drum hub and the drum axle. The shaft  24  may be rotated, and the engagement pin  26  may be aligned with the drum spring pin  72 . The pin contact portion  48  of the engagement pin  26  may then be inserted into the recess of the drum spring pin  72 . The shaft  24  may be rotated until the drum spring pin  72  pushes out the alignment pin  28  or the desired length of insertion of the drum spring pin  72  through the pin passage is achieved. 
     It can now be realized that the present invention provides tools and methods for effectively detaching and reattaching a drum of a cartridge. The present invention eases the step of aligning the mechanical spring pin with the device used to drive the mechanical spring pin out of the drum and the drum axle. The tools and methods of the present invention help minimize the exposure of sensitive parts of the drum to being damaged. For instance, the present invention helps ensure that the drum spring pin, the parts of the pin driver, or the pin removal technique does not alter the physical characteristic hub of the drum, which is often manufactured with soft plastic. The present invention helps minimize the exposure of the drum spring pin from being damaged. It can further be appreciated that the tools and methods of the present invention may provide leverage in re-installing the drum to the cartridge. The present invention provides tools and methods that may be desirable in high volume cartridge remanufacturing environments. 
     Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, the lengths and the numbers of the various shafts of the pin driver may be varied. The shape and the thickness of the tool body may be varied. The invention is capable of other embodiments and of being practiced and carried out in various ways. The invention is not limited in its application to the details of the construction and to the arrangement of the components set forth in the above description or as illustrated in the drawings.