Patent Publication Number: US-7725060-B2

Title: Skirt for toner cartridge

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
   None. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   None. 
   REFERENCE TO SEQUENTIAL LISTING, ETC. 
   None. 
   BACKGROUND 
   1. Field of the Invention 
   The present invention relates to a skirt for a toner cartridge, and more specifically relates to a skirt having a preselected geometry for use with a toner cartridge in order to inhibit creep and promote efficient movement of toner within an electrophotographic (laser) printer. 
   2. Description of the Related Art 
   Laser printers utilize a light beam which is focused to expose a discreet portion of an image transfer drum in a further attempt to attract printing toner to these discreet portions. Toner comprises a mixture of pigment, typically carbon black, and plastic. When the toner becomes electrostatically charged, the toner is attracted to exposed portions of the image transfer drum. When a medium, printing paper, passes over the rotating transfer drum, the toner is transferred to the medium. Afterward, the medium passes through a heat fuser so that the plastic is melted and permanently fused with the medium. 
   Existing laser printers utilize replaceable toner cartridges having a developer roll, a toner reservoir and a metering system. Within the toner cartridge a skirt is connected to a rotating shaft in order to define a paddle which moves the toner through one or more reservoir areas and toward the image transfer drum. The skirt sweeps and/or flicks toner from one portion of the cartridge to a second portion of the cartridge. After repeated operations, the toner becomes depleted due to the printing process. 
   There are generally three factors that influence a skirt&#39;s ability to transport toner: length, geometry and thickness. In order to work properly, the skirt must engage portions of the toner cartridge housing and must deflect to some extent for best moving the toner. However, one problem encountered during shipping of toner cartridges occurs when the cartridges are subjected to elevated temperatures of greater than 100 degrees Fahrenheit. When the skirt is subjected to such temperatures and deflected due to engagement with some portion of the toner cartridge housing, the deflection combined with the high temperatures can result in a permanently deflected skirt, which is typically referred to as “creep” of the material. A skirt which has been affected by creep is less effective in moving toner as it provides less interference with the housing and thus is limited in the amount of toner which can be transferred toward a desired location in the toner cartridge. When the skirt fails to provide an adequate amount of toner, then starvation occurs resulting in an incomplete print image or an image which is lighter than desired. 
   Software solutions have been implemented to position the skirt at a location with decreased or no contact with the toner cartridge when the cartridge is shipped or between operating cycles. However, such solution resulted in a decrease in throughput of media since the skirt was repositioned between each media page printed. With the detrimental effect to printing functionality, a mechanical solution was desirable. 
   It would be desirable if a skirt design limited or eliminated creep associated with toner cartridge paddles. 
   SUMMARY OF THE INVENTION 
   A skirt for a toner cartridge comprises a body having a pair of parallel edges, a plurality of beams extending along the body in the direction of the pair of parallel edges, the beams having a first end dimension B, the beams having a second end dimension b, the plurality of beams having tapered edges between the first end and the second end defining a ratio R defined by dimensions b/B being from about 0 to 0.9 for inhibiting creep deflection. The skirt further comprises a plurality of mounting apertures. The skirt further at least one of the plurality of mounting apertures being disposed between each of the beams. The body has a thickness of about 0.1 millimeter. The body has a thickness of about 0.2 millimeters. The body is formed of polyethylene terephthalate polyester (PET). The ratio R is about 0.27. 
   A paddle assembly for urging toner to a location within a toner cartridge, comprises a rotatable shaft, a skirt connected to the rotatable shaft, the skirt having a plurality of sides including an upper skirt edge and a lower skirt edge, a plurality of beams extending generally in the direction between the upper skirt edge and the lower skirt edge, the beams having a base portion adjacent the upper skirt edge with a dimension B and a tip portion adjacent the lower skirt edge with a dimension b, the beams being tapered from the tip portion to the base portion defining a ratio R of b to B of less than or equal to about 0.9 for inhibiting creep deflection. The beams are tapered with the ratio R being about 0.27. The paddle assembly further comprises a plurality of fasteners extending from the shaft through the skirt. The beams have a wider dimension at an upper area and a narrower dimension at a lower area. The lower edge of the skirt is an interference edge for engaging an inner surface of a toner cartridge. The paddle assembly further comprises an opening between the plurality of beams. The upper edge is disposed above the opening and the lower edge is disposed below the opening. The paddle assembly wherein the plurality of tapered beams define sides of the opening. The skirt further comprises a thickness of about 0.125 millimeters. The skirt further comprising a thickness of about 0.188 millimeters. The skirt has a thickness of between about 0.1 and 0.2 millimeters. 
   A skirt for a toner paddle comprises a body having an upper edge and a lower edge, a plurality of windows disposed between the upper edge and the lower edge of the body, the windows defined by tapered beams, the beams having a wider end near the upper edge and a narrower end near the lower end, the tapered beams being tapered having a ratio R of b/B of between about 0 to 0.9 to inhibit creep deflection. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The aforementioned features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
       FIG. 1  depicts a peripheral device having a laser print engine in perspective view; 
       FIG. 2  depicts a side-sectional view of the exemplary peripheral of  FIG. 1 ; 
       FIG. 3  depicts a perspective view of an exemplary toner cartridge; 
       FIG. 4  depicts a side-sectional view of the toner cartridge of  FIG. 3 ; 
       FIG. 5  depicts a front view of an exemplary skirt; 
       FIG. 6  depicts a graph beam width ratios to beam stiffness for optimization; 
       FIG. 7  depicts a front view of a representative beam having a first ratio; 
       FIG. 8  depicts a front view of a representative beam having an alternative ratio; 
       FIG. 9  depicts a front view of a representative beam having a further alternative ratio; 
       FIG. 10  depicts a first graph testing multiple skirt designs; and, 
       FIG. 11  depicts a second graph testing multiple skirt designs. 
   

   DETAILED DESCRIPTION 
   The following description and drawings illustrate embodiments of the invention sufficiently to enable those skilled in the art to practice it. 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 drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. For example, other embodiments may incorporate structural, chronological, electrical, process, and other changes. Examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The scope of the invention encompasses the appended claims and all available equivalents. The following description is, therefore, not to be taken in a limited sense, and the scope of the present invention as defined by the appended claims. 
   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. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings. 
   In addition, it should be understood that embodiments of the invention include both hardware and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the invention may be implemented in software. As such, it should be noted that a plurality of hardware and software-based devices, as well as a plurality of different structural components may be utilized to implement the invention. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible. 
   The term image as used herein encompasses any printed or digital form of text, graphic, or combination thereof. The term output as used herein encompasses output from any printing device such as color and black-and-white copiers, color and black-and-white printers, and so-called “all-in-one devices” that incorporate two or more functions such as scanning, copying, printing, and faxing capabilities in one device. Such printing devices may utilize ink jet, dot matrix, dye sublimation, laser, and any other suitable print formats. The term button as used herein means any component, whether a physical component or graphic user interface icon, that is engaged to initiate output. The term media and paper may be used interchangeably herein and may include plain paper, glossy photo paper, coated paper, card stock, index cards, labels, envelopes, transparency, MYLAR, fabric, or other printable materials. The term print engine, as used herein, means the at least one media feed assembly but may also include the carrier assembly and the base tray component in combination. The term operations panel, as used herein, means an interactive display allowing for menu display, menu selections, image viewing, editing of images, correction of error conditions and other operations and control functions. The term peripheral may include a single function or multi-function, or all-in-one, device which may be connected to a host computer, network connected or may be a stand-alone, which is a device which may function independently of any host computer. 
   The exemplary embodiments described herein provide a skirt for a toner cartridge which inhibits creep deflection during shipping and non-operational times and when engaging the toner cartridge and exposed to elevated temperatures. Referring now to  FIG. 1 , a perspective view of a laser printer  10  is depicted in perspective view. Although, the peripheral device is depicted, one skilled in the art should realize that the present design may alternatively be used with an all-in-one device, copier, tax, stand-along device or the like having an electrophotographic (laser) print engine. The laser printer  10  comprising a housing  12  including a primary toner access door  14  positioned on the front of the housing  12 . The housing  12  generally comprises a front surface, first and second side surfaces, a rear surface (not shown) and a bottom surface to enclose the laser printer operating mechanisms. On the front of the housing  12 , the toner access door  14  is pivotally mounted to allow opening and access for installation or removal of a toner cartridge  50  ( FIG. 2 ). The front panel of the primary access door  14  comprises a control panel  16  which includes a display  18 , an alpha numeric keypad  20 , a plurality of selection buttons  22 , as well as a flash memory slot  24 . The control panel  16  is in electronic communication with a controller (not shown), which may be embodied by one or more micro-processors, in order to operate the laser printer  10 . Beneath the primary access door  14  is a secondary access door  26  which allows access to additional toner cartridges, such as in the case where the laser printer is printing in both monochrome and color. For example, three additional toner cartridges may be utilized to provide the color printing comprising the toner colors cyan, yellow or magenta, although others colors may be utilized. 
   Beneath the access doors  14 ,  26  is an input tray access door  30 . When the input tray access door  30  is opened with a release  32 , an input tray  35  is accessible to load the printer  10  with media. The input tray may hold a stack of media for use with the laser printer  10  and further defines a starting point of a media feedpath  34  ( FIG. 2 ) extending from the media input tray to a media output tray  36 . The media feedpath  34  may be a duplex feedpath, as depicted, or a simplex feedpath. The media output tray  36  is located on top of the housing  12  and generally extends rearwardly to store printed media processed by the laser printer  10 . 
   Referring now to  FIG. 2 , the laser printer  10  is shown in side-section view. The primary toner access door  14  is raised and the secondary toner cartridge access door  26  is opened allowing positioning of a toner cartridge  50  within the housing  12 . The toner cartridge  50  is shown in solid line for positioning within the printer  10 . The cartridge  50  is also shown in broken line within printer  10  in broken line adjacent the feedpath  34 . Also, as shown in  FIG. 2 , the feedpath  34  is depicted extending between the input tray  35  and the output tray  36 . 
   Referring now to  FIG. 3 , a perspective view of the toner cartridge  50  is depicted in perspective view. The toner cartridge  50  is depicted with an upper portion or lid removed so that to depict an interior of the cartridge  50  and a paddle  80  exploded from the cartridge  50 . Although a single paddle  80  is depicted for purpose of clarity, multiple paddles may be used corresponding to the member of toner sumps within the cartridge  50 . The toner cartridge  50  comprises a housing  51  having a first wall  52  and an opposed second wall  54  with a lower support surface or floor  56  extending between the first side wall  52  and the second side wall  54 . The first and second side walls  52 ,  54  and the floor  56  define, in part, a toner reservoir  58  having a first toner sump  60 , a second toner sump  62  and a third toner sump  64 . The sumps  60 ,  62 ,  64  are storage areas or compartments within the cartridge  50  where toner (not shown) is positioned for printing with the laser printer  10 . Although three toner sumps  60 ,  62 ,  64  are depicted in the exemplary embodiment, one skilled in the art should realize that reservoirs of various size and shape and well as varying numbers of toner sumps may be utilized. According to the exemplary toner cartridge  50  depicted, three toner paddles  80  are utilized, one for each sump  62 ,  64 ,  66  in order to move toner from the first sump  60  to the third sump  64  and on to a toner adder roller (not shown) and further on to a developer roller (not shown) until the toner is deposited on an imaging drum (not shown). 
   The floor  56  further comprises at least one interference feature to aid movement of toner. Located in between the first toner sump  60  and the second toner sump  62  is an interference feature  66  which provides a surface against which the paddle  80  may create a force to move toner. Engagement of the paddle  80  and the interference feature  66  aids with movement of the toner from the first sump  60  to the second sump  62 . A second interference feature  68  is also positioned between the second toner sump  62  and the third toner sump  64 . Interference features  66 ,  68  aid the rotating paddles in moving toner from sump to sump for subsequent movement to a toner adder roller and developer roller. 
   Depicted along the first sidewall  52  are paddle journal apertures  61 ,  63  and  65 . Each of the journal apertures  61 ,  63 ,  65  provides a pivoting location for a paddle  80  positioned within the toner cartridge  50 . The paddles  80  are driven to rotate by a transmission (not shown), such as gear transmission, located on the outward side of the first sidewall  52 . Opposite each of the journal apertures  61 ,  63 ,  65  are a plurality of keyways  67  ( FIG. 4 ) which receives the opposite end of paddles  80 . Thus two opposed positions are created for receiving each paddle  80  and allowing for pivotal motion of each paddle  80  in order to move toner in reservoir  58  from a first end to a second end of cartridge  50 . 
   Moving from the paddle journal aperture  65 , in a direction opposite from the first toner sump  60  of the journal aperture  61 , a hump  70  extends from the floor  56 . The hump  70  is larger than the interference features  66 ,  68 . The hump  70  has a height which is greater than the interference features  66 ,  68 . This causes increased interference engagement with the skirt  84  and further results in toner being flung into the air and on to a toner adder roll. Moving further from the journal aperture  65  opposite hump  70  are apertures  75  on the first and second sidewalls  52 ,  54  and an area for receiving a toner adder roller. The toner adder roller (not show) is a foam roller which receives toner from flung upwardly by the engagement between skirt  84  and hump  70 . The toner adder roller must be thoroughly coated with toner therefore the hump  70  and skirt  84  fling toner upwardly to provide better coating on the toner adder roller. The toner adder roller engages a developer roller (not shown) to transfer toner from the toner adder roller. The developer roller is housed between journal apertures  77  to rotate within the cartridge  50 . 
   Exploded from the toner cartridge  50  is the paddle  80 . A single paddle  80  is depicted for clarity however one skilled in the art should realize that multiple paddles may be utilized or alternatively a single paddle may be utilized based on the configuration of toner sumps within the cartridge  50 . The paddle  80  comprises a shaft  82  having a first end  81  and a second end  83 . The first end  81  is positioned within the one of the apertures of first wall  52 . On the opposite side of the first sidewall  52 , the gear transmission, as previously described, is operably engaging the shaft  82  to rotate the paddle  80 . The shaft  82  is depicted as obloid shaped however various shapes may be utilized. Connected to the shaft  82  is an attachable skirt  84  which engages the floor  56  and hump  70  to fling toner in the air to properly coat the toner adder roller. The shaft  82  includes a plurality of fasteners  88  extending through mounting apertures  87  in the skirt  84 . The fasteners  88  may be a plurality of meltable structures which are melted and flattened during manufacture to form a head outside of the shaft  82  and to retain the skirt  84  on the shaft  82 . However, alternative fasteners may be utilized such as rivets, screws, or the like. 
   Within the second sidewall  54 , a toner fill aperture  55  is disposed in order to allow filling of the toner cartridge  50  during manufacture. The aperture  55  is oblong in shape in order to allow faster filling of toner, although various shapes may be utilized. A plug (not shown) covers the aperture  55  once the toner cartridge  50  is filled. 
   Referring now to  FIG. 4 , a side section view of the toner cartridge  50  is shown. Specifically, the inside of the second sidewall  54  is depicted as well as the floor  56  and the first and second interference features  66 ,  68 . Located within the forwardmost, middle and rearmost keyways  67  are paddles  80   a ,  80   b , and  80   c  having skirts  84   a ,  84   b , and  84   c  extending from shafts  82   a ,  82   b ,  82   c , respectively. Operation of paddle  80   a  in forwardmost keyway  67  in third toner sump  64  will be described. The fasteners  88   a ,  88   b , and  88   c  for skirts  84   a ,  84   b , and  84   c , respectively, are depicted in an unflattened state, however, as previously described, such fasteners are melted and flattened during manufacture of the present invention. The skirt  84   a  extends from the shaft  82   a  and engages the third toner sump  64  at position X. As seen in  FIG. 4 , the radius of the third toner sump  64  varies as the floor  56  moves upwardly into the hump  70 . Due to the dimension of the skirt  84   a  extending from the shaft  82   a  and the varying radius of hump  70 , the skirt  84   a  flexes as the paddle  80   a  rotates in the clockwise direction. The flexing of the skirt  82   a  causes the storage of energy which is required to fling the toner located in the third toner sump  64 . At position Y, the flexing of the skirt  84   a  is depicted in broken line with the paddle  80   a  rotated in the direction indicated by arrow W. As the paddle  80   a  rotates further to a third position at Z which is depicted in broken line, the paddle  80   a  is again shown with skirt  84   a  in an unflexed position. In this position the energy stored within the skirt  84   a  has been released so that the toner is flung into the air. The amount of toner flung, the height and distance are all dependent upon the amount of energy stored in the skirt  84   a  during engagement of the paddle  80   a  and hump  70  while in operation. Other relevant factors in the calculus of insuring proper toner coverage of the toner adder roll (not shown) include, but are not limited to, thickness of the skirt  84   a  and geometry of beams located within the skirt  84   a . As seen in the figure, the hump  70  extends higher than the interference features  66 ,  68 . This provides that the skirt  84   a  remains flexed for a longer period of time and flexed a greater distance than skirts  84   b ,  84   c . With skirt  84   a  flexed for a longer period of time and distance, stored energy in skirt  84   a  is released and the toner is flung when skirt  84   a  is at a higher position causing more upward direction of motion for the toner and better coverage of the toner on the toner adder roll. 
   Referring now to  FIG. 5 , skirt  84  is shown in front view. The exemplary skirt  84  is formed of polyethylene terephthalate polyester (PET), having the trade name MYLAR, although other materials may be utilized. The polyethylene terephthalate polyester (PET) is somewhat flexible yet firm enough to urge movement of toner within the cartridge  50  as the paddle  80  rotates. The skirt  84  has an upper edge  85  and a continuous lower edge  86  with a plurality of spaced apart tapered beams  90  extending between and connected to both the upper edge  85  and a continuous lower edge  86 . The skirt  84  also comprises first and second ends having parallel edges and corresponding to adjacent first and second sidewalls  52 ,  54  of toner cartridge  50  ( FIG. 3 ). A plurality of openings or windows  89  are disposed between the upper edge  85  and the lower edge  86 . Disposed between selected windows  89  are fastener openings or mounting apertures  87  which allow the fasteners  88  to pass through allowing for connection of the skirt  84  to the shaft  82 . Each of the windows  89  are separated by a beam  90 . The windows  89  are quadrilateral in shape however other shapes may be used which incorporate the beam taper angles described. The beams  90  include tapered edges  91  providing the angled sides of the windows  89 . The beams  90  taper from a wider portion “B” at an upper edge  93  of the skirt window  89  to a narrower portion “b” toward the bottom edge  95  of the skirt window  89 . The measurement “B” is a width between windows  89  at adjacent the upper edge  85  of the beam  90  while the measurement “b” is a width between windows  89  adjacent the lower edge  86  of the beam  90 . Tapered beams  90 , with a B greater than b, inhibit the phenomenon known as creep deflection in the skirt  84 . During shipping of the toner cartridges, printers and also during times when the printer is stopped, the skirt  84  may be positioned wherein the skirt  84  is resting on the hump  70  or otherwise engaging the cartridge  50  causing deflection of the skirt  84 . With prior art skirts, when a skirt came to rest against such a feature, high heat conditions, to which the cartridge may be exposed, for example during shipping, resulted in creep deflection of the skirt. At high temperatures and extended periods of time, prior art skirts may creep to a permanently deformed state which fail to properly engage the cartridge and fail to move toner efficiently and effectively during subsequent operation. The present skirt  84  includes tapered beam members  90  disposed between and defining the windows  89 . The greater the taper of the beams  90 , inhibits creep by decreasing beam stiffness, reducing internal stress, and therefore promotes improved performance of the skirt  84 . 
   As measured from the horizontal, defined along the lower edge  86  of the skirt  84 , the tapered beam/window edge  91  may be between about 45 degrees and 80 degrees. 
   Referring now to  FIG. 6 , a graph is depicted relating beam width ratios between the width near the tip “b” and the width near the base “B”. The ratio is plotted versus relative beam stiffness. The stiffness is calculated by first calculating beam deflection for a tapered beam of rectangular cross-section utilizing the following equation:
 
Beam Deflection (Maximum) For A Tapered Beam of Rectangular Cross Sections,  Y, Y= 12 P /( EF   2 ){ C   2   /F  log [( C+FL )/ C]+L/ 2( FL− 2 C )}
 
Where:
 
C=Rh 3  
 
F=(1−R)h 3 /L
 
Ratio Of Large Base B To Tip Base b, R=b/B
 
Height of Rectangular Section (Constant), h
 
Length of Beam (Constant), L
 
Force Applied to Beam (Constant), P
 
Deflection of Beam, Y
 
Beam Stiffness Equation: K=P/Y
 
Where:
 
Stiffness of Beam, K
 
Next the beam deflection is utilized to calculate the relative beam stiffness charted in  FIG. 6 . In order to minimize the bending stress developed in the cantilever beam  90 , the stiffness must be minimized. For example, if two beams of equal length, one of which is stiffer than the other, are deflected an equal amount the stiffer beam will be more likely to fail as the stress to create its deflection is higher. Any given material has a certain stress limit at which it plastically deforms, and then later a stress at which it fails completely. Therefore, reading the chart in  FIG. 6 , the best possible tapered beam configuration is one in which the beam width at the tip is 0. Visually, this would represent a triangular beam, with a taper angled such that the tip of the beam is a point. It is considered desirable to have a beam with characteristics of least stiffness, left most portion of the curve, minimizing K while supporting the interference edge with a manufacturable amount of plastic. Another consideration is to maintain the ability to move enough toner to adequately coat a toner adder roll. If the tip dimension “b” is too small, the possibility arises that there may not be enough surface area to move a sufficient amount of toner with the skirt  84 . After testing, the ratio R defined by b/B was found to be suitable between the values of about 0 and 0.9. The ratio R was found to be optimal around 0.27 and provided a relative beam stiffness of about 0.198.
 
   Referring now to  FIG. 7 , an exemplary beam  90  is depicted in front view corresponding to the position of the beam  90  in  FIG. 5 . The beam  90  includes tapered edge  91  defining sides of the windows  89  ( FIG. 5 ). The tapered edges  91  extend between a base portion having a dimension labeled “B” and a tip portion having a dimension labeled “b”. The base portion, tip portion and tapered edges define the four sides of the beam  90 . The corresponding dimensions depicted in the illustrative figure are B=1 and b=0.9. These dimension provide the ratio R of b/B equal to 0.9. 
   Referring now to  FIG. 8 , an alternative beam  190  is depicted in front view also corresponding to a position of the beam  90  in  FIG. 5 . The beam  190  also includes a base portion B with a dimension equal to 1 unit. The tip portion b has a dimension equal to zero (0). Accordingly, the beam  190  is depicted as triangular in shape. Tapered beam edges  191  extend between the base portion B and the tip portion b. According to the beam shape depicted in  FIG. 8 , the ratio R of b/B is equal to zero (0). 
   Referring now to  FIG. 9 , a further alternative beam  290  is depicted in front view as described in  FIGS. 7 and 8 . The beam  20  comprises a base portion having a dimension B and a tip portion having a dimension b. The tapered edges  291  extend between the base portion and tip portion of the beam  290 . The beam  290  has a ratio R of b/B equal to 0.1. As previously described, upon further testing a desirable ratio of about R=0.27 was found to provide desirable characteristics for moving toner while inhibiting creep for the current cartridge architecture. As one skilled in the art will understand, such value may change with variation in cartridge design. 
   Referring now to  FIG. 10 , according to a first example, skirt deflection of a variable number of beams over a period of time at an elevated temperature in order to re-create environmental conditions during shipping. As indicated, a skirt with straight, non-tapered beams (R=1) is shown in solid line with alternative tapered beam designs shown in varying broken lines. The skirt with the least deflection utilized a greater number of tapered beams. 
   Referring now to  FIG. 11 , according to a second example, the skirt deflection was again compared during a time period at an elevated temperature. The variable characteristic was the thickness of the skirt and the relationship with the skirt deflection. As indicated in the Figure, the skirts tested included thicknesses of 0.125 millimeter, 0.1 millimeter, 0.16 millimeter and 0.25 millimeter. Additionally, one non-tapered skirt was tested in addition to a tapered skirt, which is indicated as a straight beam. Of the various thicknesses tested, the thicker tapered beam skirt performed better having the least amount of deflection of the skirts tested. Additionally, thicker skirts create larger forces for flinging toner within the cartridge. Unfortunately, however, those increased forces caused increased vibration of the cartridge, increased toner leaks, and fine line jitter due to the increased thickness of the skirt. This unexpected result led to the thinning of the skirt to an operable dimension which reduced or eliminated the vibration, toner leaks and the like while providing proper toner delivery. A range of usable skirt thicknesses for current cartridge architecture was determined to be between about 0.1 and 0.2 millimeters. Accordingly, an optimized skirt thickness of 0.10 millimeters is utilized, however, one skilled in the art should realize that with varying cartridge design, skirt dimensions may vary as well. 
   The foregoing description of the various embodiments of the invention has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the invention to the precise steps and/or forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be defined by the claims appended hereto.