Patent Publication Number: US-8977160-B2

Title: Overmolded shutter for use in toner containing supply items of an imaging apparatus

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 Disclosure 
     The present disclosure relates generally to toner cartridges and developer units used in electrophotographic imaging devices such as a printer or multifunction device having printing capability, and in particular shutters used to open and close toner ports on such toner cartridges and developer units. 
     2. Description of the Related Art 
     In toner cartridge design it is now common practice to separate the longer lived components from those having a shorter life. This has led to having the longer lived developing components such as the developer roll, toner adder rolls, doctor blades, the foregoing are also referred to as a developing unit, photoconductive drums, cleaning and charge rollers and a waste bin to be in separate assemblies from the toner cartridge. The toner supply, which is consumed relatively quickly in comparison to the previously described components, is provided in a reservoir in a separate toner cartridge that mates with the developer unit. The toner cartridge has a reduced number of components and is often referred to as a toner bottle even though it is more than a mere bottle for holding toner. Because both the developer unit and toner cartridge are each separable and removable from the imaging apparatus, both use shutter assemblies to open and close their respective toner entry port and toner exit port. 
     To deliver the toner from the toner cartridge to the developer unit, an auger in the toner cartridge may be used to feed toner from the toner cartridge via an exit port on the toner cartridge into an entry port on the developer unit and into a second auger that disperse the toner within the developer unit. As the toner is drawn out of the cartridge unit, it is augured through a shutter. The shutter in one position seals the exit port of the toner cartridge when it is not inserted in the imaging apparatus. Another shutter may be used for sealing the entry port of the developer unit when the toner cartridge has been removed. 
     The shutters in such shutter assemblies are rotatably mounted in the housings of the toner cartridge and the developer unit and are generally tapered or conical. This mounting requires that the spacing between the shutter and the housing be sealed in order to prevent a toner leak path from occurring between the shutter and the housing. Prior seals have been made from foam materials that are adhesively wrapped around the exterior of the shutter or rubber O-rings were used. 
     One problem with the traditional application of foam seals or O-rings is that it is difficult to have low frictional force between the shutter and the housing while maintaining proper sealing performance. Additionally, in some cases there are space constraints between the shutter and housing making it difficult to insert the shutter having a foam seal into the housing. The use of wrapped foam seals and O-ring seals result in high rotational frictional force during actuation of the shutter for opening and closing the toner port. This high frictional force must be overcome by a large force applied to the toner cartridge supplied by the shutter operator such as a plunger on a door of the imaging apparatus or by an arbor spring on the developer unit. If not, this will lead to risk of the shutter not fully opening which will impact the rate at which toner can be delivered or not fully closing which will increase the risk of toner leakage. 
     Another problem with the wrapped foam application is it is difficult to wrap a foam seal around a conically shaped shutter while aligning the mating joints and aligning the seal openings with the port openings in the shutter. This process can result in excessive rotational frictional force, foam misalignment and toner leakage. 
     To provide a seal for a supply item having a high effective sealing force without a high rotation frictional force would be advantageous. It would be a further advantage to have such a seal to prevent toner escaping from the supply item, such as a toner cartridge or developer unit, during shipping, storage, and when removed from the imaging apparatus. It would be a further advantage to be able to provide a shutter that will open fully to ensure a high rate of toner delivery. 
     SUMMARY 
     A shutter is shown for mounting in a housing of a supply item for an imaging apparatus. The shutter, when installed, is rotatable between a first position and a second position for closing and opening a port within the housing through which toner can flow. The shutter comprises a body including a cylindrical hollow portion, the hollow portion sized to be received within a corresponding opening in the housing adjacent the port, the hollow portion having a first opening and a second opening forming a channel therebetween for carrying toner wherein, when the shutter is in the first position, the first and second openings are not in fluid communication with the port and, when the shutter in the second position, one of the first and the second openings is in fluid communication with the port allowing for toner to pass through the port; and a seal overmolded onto the exterior of the body. The seal comprises a sleeve molded around the exterior of the body and positioned upstream of the one of the first and second openings that is in fluid communication with the port; and an endless rib molded on the sleeve, extending outwardly at an acute angle from the sleeve and having a height that is greater than a height of a gap formed between the body and a corresponding opening in the housing when the shutter is installed in the housing. When the shutter is installed in the opening in the housing, the endless rib deflects forming a sealing interface with the housing. 
     A plurality of gusset ribs may be spaced about the endless rib with each gusset rib molded between a face of the endless rib and the sleeve. The endless rib may be angled in one of a downstream orientation and an upstream orientation. A plurality of endless ribs may be provided, with endless ribs positioned upstream and downstream of the opening in the shutter that is in fluid communication with the port. The seal may be molded from a material selected from a group consisting of thermoplastic elastomers (TPE), thermoplastic urethanes, thermoplastic vulcanizates and silicon rubber. In a further embodiment, the endless rib may have a number of different rib profiles including a C-shaped profile and an S-shaped profile. Scoring on the outer surface of the shutter body may be provided to increase adherence of the molded seal to the surface of the shutter body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of the disclosed embodiments, and the manner of attaining them, will become more apparent and will be better understood by reference to the following description of the disclosed embodiments in conjunction with the accompanying drawings. 
         FIG. 1  is a block diagram of an example imaging system having an imaging unit and toner cartridge. 
         FIG. 2  is an illustration of one embodiment of an imaging unit and toner cartridge. 
         FIG. 3  is an illustration of the combination of a toner cartridge and a developer unit utilizing shutter assemblies. 
         FIG. 4  is an illustration of the toner cartridge and developer unit of  FIG. 3  shown in a partially assembled condition. 
         FIG. 5  is a partial sectional view of a toner cartridge shutter assembly shown in  FIG. 4  having one embodiment of an overmolded shutter of the present invention. 
         FIG. 6  is a close-up view of a portion of  FIG. 5  illustrating the interface between the toner cartridge housing and the overmolded shutter. 
         FIG. 7  is sectional view taken along line  7 - 7  of  FIG. 4  illustrating the axial and endless ribs of the overmolded shutter in one embodiment of the present invention. 
         FIG. 8  is an exploded view of the shutter assembly illustrated in  FIGS. 4-6 . 
         FIG. 9  is a perspective view of a shutter and overmolded seal showing a second end of an air duct. 
         FIG. 10  is a sectional view of the shutter of  FIG. 9  taken along section line  10 - 10  in  FIG. 9 . 
         FIG. 11  is a perspective view illustrating scoring on the shutter body prior to overmolding of the seal onto the shutter. 
         FIG. 12  is a perspective view of an alternative embodiment of an overmolded shutter. 
         FIG. 13  is a sectional view of the shutter of  FIG. 12  taken along section line  13 - 13  in  FIG. 12 . 
         FIGS. 14-18  are example schematic illustrations of endless rib configurations for the overmolded shutter of the present invention. 
         FIGS. 19-22  are example embodiments of rib profiles for endless and transverse ribs for the overmolded shutter of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the present disclosure 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 present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. 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. 
     Spatially relative terms such as “top”, “bottom”, “front”, “back”, “rear” and “side” “under”, “below”, “lower”, “over”, “upper”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are generally used in reference to the position of an element in its intended working position within an imaging device. The terms “left” and “right” are as viewed with respect to the insertion direction of a unit into the imaging device. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc. and are also not intended to be limiting. Like terms refer to like elements throughout the description. 
     As used herein, the terms “having”, “containing”, “including”, “comprising”, and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise. 
     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 multiple functions such as scanning, copying, and printing capabilities in one device. The term “button” as used herein means any component, whether a physical component or graphic user interface icon, that is engaged to initiate output. 
     Referring now to the drawings and particularly to  FIG. 1 , there is shown a diagrammatic depiction of an imaging system  20  embodying the present invention. As shown, imaging system  20  may include an imaging apparatus  22  and a computer  24 . Imaging apparatus  22  communicates with computer  24  via a communications link  26 . As used herein, the term “communications link” is used to generally refer to structure that facilitates electronic communication between multiple components, and may operate using wired or wireless technology and may include communications over the Internet. Imaging system  20  may be, for example, a customer imaging system, or alternatively, a development tool used in imaging apparatus design. 
     In the embodiment shown in  FIG. 1 , imaging apparatus  22  is shown as a multifunction machine that includes a controller  28 , a print engine  30 , a laser scan unit (LSU)  31 , an imaging unit  32 , a cleaner unit  33 , a developer unit  34 , a toner cartridge  35 , a user interface  36 , a media feed system  38  and media input tray  39  and a scanner system  40 . Imaging apparatus  22  may communicate with computer  24  via a standard communication protocol, such as for example, universal serial bus (USB), Ethernet or IEEE 802.xx. A multifunction machine is also sometimes referred to in the art as an all-in-one (AIO) unit. Those skilled in the art will recognize that imaging apparatus  22  may be, for example, an electrophotographic printer/copier including an integrated scanner system  40 ; or a standalone scanner system  40 . 
     Controller  28  includes a processor unit and associated memory  29 , and may be formed as one or more Application Specific Integrated Circuits (ASICs). Memory  29  may be any volatile on non-volatile memory or combinations thereof such as, for example, random access memory (RAM), read only memory (ROM), flash memory, and/or non-volatile RAM (NVRAM). Alternatively, memory  29  may be in the form of a separate electronic memory (e.g., RAM, ROM, and/or NVRAM), a hard drive, a CD or DVD drive, or any memory device convenient for use with controller  28 . Controller  28  may be, for example, a combined printer and scanner controller. 
     In the present embodiment, controller  28  communicates with print engine  30  via a communications link  50 . Controller  28  communicates with imaging unit  32  and processing circuitry  44  thereon via a communications link  51 . Controller  28  communicates with toner cartridge  35  and processing circuitry  45  therein via a communications link  52 . Controller  28  communicates with media feed system  38  via a communications link  53 . Controller  28  communicates with scanner system  40  via a communications link  54 . User interface  36  is communicatively coupled to controller  28  via a communications link  55 . Processing circuits  44 ,  45  may provide authentication functions, safety and operational interlocks, operating parameters and usage information related to imaging unit  32  and toner cartridge  35 , respectively. Controller  28  serves to process print data and to operate print engine  30  during printing, as well as to operate scanner system  40  and process data obtained via scanner system  40 . 
     Computer  24 , which may be optional, may be, for example, a personal computer, network server, tablet computer, smartphone or other hand-held electronic device, including memory  60 , such as volatile and/or non-volatile memory, input device  62 , such as a keyboard, and a display, such as monitor  64 . Computer  24  further includes a processor, input/output (I/O) interfaces, and may include at least one mass data storage device, such as a hard drive, a CD-ROM and/or a DVD unit (not shown). 
     Computer  24  includes in its memory a software program including program instructions that function as an imaging driver  66 , e.g., printer/scanner driver software, for imaging apparatus  22 . Imaging driver  66  is in communication with controller  28  of imaging apparatus  22  via communications link  26 . Imaging driver  66  facilitates communication between imaging apparatus  22  and computer  24 . One aspect of imaging driver  66  may be, for example, to provide formatted print data to imaging apparatus  22 , and more particularly, to print engine  30 , to print an image. Another aspect of imaging driver  66  may be, for example, to facilitate collection of scanned data. 
     In some circumstances, it may be desirable to operate imaging apparatus  22  in a standalone mode. In the standalone mode, imaging apparatus  22  is capable of functioning without computer  24 . Accordingly, all or a portion of imaging driver  66 , or a similar driver, may be located in controller  28  of imaging apparatus  22  so as to accommodate printing and scanning functionality when operating in the standalone mode. 
     Print engine  30  may include a laser scan unit (LSU)  31 , an imaging unit  32 , a toner cartridge  35 , and a fuser  37 , all mounting within imaging apparatus  22 . The imaging unit  32  further includes a cleaner unit  33  housing a waste toner removal system and a photoconductive drum, and a developer unit  34  that are removably mounted within imaging unit  32 . In one embodiment the cleaner unit  33  and developer unit  34  are assembled together and installed into a frame forming the imaging unit  32 . The toner cartridge  35  is then guided by the frame into a mating relation with the developer unit  34 . Laser scan unit  31  creates a latent image on the photoconductive drum in the cleaner unit  33 . The developer unit  34  has a toner sump containing toner which is transferred to the latent image on the photoconductive drum to create a toned image. The toned image is subsequently transferred to a media sheet received in the imaging unit  32  from media input tray  39  for printing. Toner remnants are removed from the photoconductive drum by the waste toner removal system. The toner image is bonded to the media sheet in the fuser  37  and then sent to an output location or to one or more finishing options such as a duplexer, a stapler or hole punch. 
     The toner cartridge  35  removably mates with the developer unit  34  in imaging unit  32 . An exit port on the toner cartridge  35  communicates with an entry or inlet port on the developer unit  34  allowing toner to be periodically transferred from the toner cartridge  35  to resupply the toner sump in the developer unit  34 . 
     Referring now to  FIG. 2 , an example embodiment of the imaging unit  100  is shown. Imaging unit  100 , as illustrated, comprises developer unit  400 , a cleaner unit  600  and a frame  800 . Developer unit  400  and cleaner unit  600  are assembled together with frame  800 , with toner cartridge  200  being slidably received on frame  800 . The imaging unit  100  is initially slidably received in the imaging apparatus  22 . The toner cartridge  200  is guided by frame  800  into operative engagement with the developer unit  400 . This arrangement allows the toner cartridge  200  to be removed and reinserted easily when replacing an empty toner cartridge without having to remove imaging unit  100 . Should a media jam occur beneath the imaging unit  100 , the toner cartridge  200  and imaging unit  100  may be readily removed to allow access to the media jam. The developer unit  400 , cleaning unit  600  and frame  800  may also be readily removed and reinserted when required; however, this would normally occur with less frequency than the removal and reinsertion of toner cartridge  200 . 
     In  FIGS. 3 and 4 , an example embodiment of the toner cartridge  200  and developer unit  400  is shown. For simplicity, cleaner unit  600  and frame  800  are not shown. The large arrow shown in  FIG. 3  indicates the insertion direction of the cartridge  200  into the frame  800  where it mates with developer unit  400  of the imaging unit  100 . The arrow also points toward what is termed the “front” of these various elements. Toner cartridge  200  comprises a housing  202  having a reservoir  204  enclosed therein (see  FIG. 4 ) for holding a quantity of toner. Housing  202  may be viewed as having a top or lid  206  mounted on a base  208 . Base  208  includes first and second side walls  210 ,  212 , connected to adjoining front and rear walls  214 ,  216 . Top  206  may be ultrasonically welded to base  208  forming reservoir  204 . First and second end caps  218 ,  220  are also mounted to housing  202  and include guides  222  to assist with supporting and inserting toner cartridge  200  for mating with developer unit  400 . First and second end caps  218 ,  220  may be snap fitted into place or attached by screws or other forms of fasteners. Guides  222  travel in channels provided within the housing of the imaging apparatus so that toner cartridge  200  does not load down the developer unit  400 . Guides  226  may also be provided on base  208  to assist with insertion and removal of toner cartridge  200 . A handle  224  may be provided on top  206  to assist with insertion and removal of toner cartridge  200  from the imaging unit  100 . A fill port  225  is provided on second side wall  212  and is used to fill toner reservoir  204  with toner. After filling, fill port  225  would be closed by a plug or cap. 
     Various drive gears are housed within a space formed between first end cap  218  and first side wall  210  with main interface gear  228  being visible. Various interlocks and linkages may also be housed within the space formed between second end cap  220  and second side wall  212 . Mounting structures  229  may be provided on the exterior surfaces of first and second side walls  210 ,  212  for use with the interlocks and linkages. Main interface gear  228  engages with a drive system within imaging apparatus  22  which provides torque to main interface gear  228 . A paddle is rotatably mounted within toner reservoir  204  with first and second ends of a drive shaft of the paddle extending through aligned openings  244  in the first and second side walls  210 ,  212 , respectively. A drive gear is provided on the first end of the drive shaft of the paddle and engages with main interface gear  228  either directly or via one or more intermediate gears. First side wall  210  may also be termed the “drive” or “driven” side of toner cartridge  200 . 
     A channel extending along the width of front wall  214  between the first and second side walls  210 ,  212  houses an auger and a shutter assembly  300 . In one embodiment channel  250  is positioned above the axis of rotation of the drive shaft of the paddle. Channel  250  may be integrally molded as part of front wall  214  or be formed as a separate component that is attached to front wall  214 . Channel  250  is generally horizontal in orientation along with toner cartridge  200  when toner cartridge  200  is installed in imaging unit  100 . An end of the auger extends through first side wall  210  and a drive gear is provided which engages with main interface gear  228  either directly or via one of more intermediate gears. A bushing may be provided where the end of the auger passes through first side wall  210 . A similar bushing may be provided on each of the ends of the paddle where they pass through the first and second side walls  210 ,  212 . Shutter assembly  300  is provided on the front wall  214  of housing  202  adjacent side wall  212  at one end of channel  250 . 
     Referring also to  FIG. 4 , channel  250  comprises an open portion and an enclosed portion  254 . The open portion is open to the toner reservoir  204  and extends from the first side wall  210  toward the second side wall  212  to the shutter assembly  300 . Enclosed portion  254  of channel  250  extends from the second side wall  212  and encloses a shutter  302  of shutter assembly  300 . The paddle, as it rotates, delivers toner from the toner reservoir  204  into the open portion of channel  250 . The auger rotates to deliver toner received in channel  250  to the shutter  302  which is housed in the enclosed portion  254  of channel  250 . An exit port  256  is provided through the wall  258  forming the enclosed portion  254  of channel  250 . Shutter  302  rotates between a first position where it closes exit port  256  and a second position where exit port  256  is open. As illustrated, exit port  256  is disposed at the bottom of channel  250  so that gravity will assist in having toner exit through exit port  256 . 
     Referring to  FIGS. 5-7 , a passageway  260 , separate from channel  250 , is provided in the housing  202  from the shutter assembly  300  to the toner reservoir  204 . In  FIG. 5  shutter  302  is in fully opened or second position. As illustrated, passageway  260  extends between shutter assembly  300  to about the apex of the lid  206 . A first end  262  of the of passageway  260  is in fluid communication with the enclosed portion  254  of channel  250  while a second end  264  of passageway  260  is in fluid communication with reservoir  204  and disposed above the toner contained within the reservoir  204  to reduce possible blockage of the second end  264  of passageway  260  by the toner. Passageway  260  is routed away from the path along which toner is delivered so that it will not become blocked by toner exiting toner cartridge  200 . A one-way valve that is biased to close is provided at the second end  264  of passageway  260  but is openable by air traveling along passageway  260  from developer unit  400  allowing the air to enter into toner reservoir  204 . Passageway  260  and a duct in the shutter  302  form an airway to allow higher pressure air to exit from the developer unit  400  and enter into reservoir  204 . 
     Referring to  FIGS. 5-11 , an example shutter assembly  300  having an overmolded shutter  302  for the toner cartridge  200  is shown. Shutter assembly  300  includes a shutter  302 , a retainer  304  and a lever  306 . In general, lever  306  is used to move shutter  302  between a first position where the exit port  256  is closed to channel  250  and a second position where the exit port  256  is open to channel  250 . A linkage (not shown) housed in second end cap  220  actuates lever  306  to move shutter  302  between the first and second positions during insertion and removal of toner cartridge  200 . A stop  310  is provided on one end of the shutter body  303 , as shown, on drive portion  312 . Stop  310  travels in a channel provided in retainer  304 . The length of the channel in retainer  304  limits the travel of shutter  302  to between the first and second positions. Other forms of travel stops and other locations for the stop may be used as is known in the art. 
     In an example embodiment shutter  302  has a generally cylindrical body  303 . Shutter body  303  has a drive portion  312  and a hollow portion  314 . Shutter  302  is inserted into the enclosed portion  254  of channel  250  in housing  202  aligning the hollow portion  314  of shutter  302  with an end of the auger. Shutter  302  is rotatable within enclosed portion  254  of channel  250 . Drive portion  312  passes through an opening  316  in retainer  304  and is rotatable within opening  316 . Fasteners  268  are inserted through openings  318  in retainer  304  and are received in corresponding openings  270  in housing  202  rotatably securing shutter  302  in housing  202  (see  FIGS. 3 and 4 ). Drive portion  312  has one or more keys  320  that are received into corresponding one or more keyways  324  in opening  322  of lever  306  to ensure proper orientation of lever  306  with shutter  302 . Another fastener  308 , such as a screw, passes through openings  322 ,  316  and is received in opening  326  provided on the end of drive portion  312  securing lever  306  to shutter  302 . A connection pin  325  is provided at the distal end of lever  306  for attaching a drive linkage used for operating of lever  306 . It will be realized that alternatively one or more keys may be provided on lever  306  and be received in corresponding one or more keyways provided in drive portion  312  of shutter  302 . Other forms of fasteners may also be used. 
     Hollow portion  314  extends from an inner end  328  of the shutter  302  toward an outer end  330  of the shutter  302  and has an open end  332  and a closed end  334 . Open end  332  and hollow portion  314  are sized to rotatably receive an end of the auger and provide support for the auger. Exit opening  336  is provided through a wall  333  of hollow portion  314 . A channel  337  is formed in shutter  302  between the open end  332  and exit opening  336  through which exiting toner passes on its way to the exit port  256 . When the shutter  302  is in its second or open position, rotation of the auger pushes toner in channel  250  through channel  337  and out exit opening  336  where it falls through exit port  256 .  FIGS. 5 and 7  illustrate the position of shutter  302  when in its second position or open position in toner cartridge  200 . When in its first position or closed position in toner cartridge  200 , the shutter  302  would be rotated approximately ninety degrees. 
     A duct  340  having first and second ends  342 ,  344  passes through shutter  302  and is disposed within drive portion  312 . First end  342  of duct  340  is positioned near exit opening  336 . Example duct  340  is shown routed through shutter  302  along a diameter thereof and does not intersect with channel  337 . However, other routings for duct  340  may be used through drive portion  312  of shutter  302 . In one embodiment a deflection rib  338  is disposed near closed end  334  of hollow portion  314 . Deflection rib  338  directs toner leaving exit opening  336  away from first end  342  of duct  340  and into exit port  256 . Deflection rib  338  may extend into exit port  256 . Deflection rib  338  helps to block exiting toner leaving exit opening  336  from entering duct  340 . Shutter body  303  may be cylindrical or may taper slightly inwardly along the hollow portion  314 . 
     The outer dimension of the shutter body  303  is smaller than the dimension of the opening in the enclosed portion  254  of channel  250  in housing  202  forming a gap G therebetween (see  FIG. 6 ). The gap G allows the shutter  302  to be rotated between its first and second positions but creates a toner leak path. The upstream end of leak path is at the end of channel  250  adjacent the inner end  328  of shutter body  303 , and flows downstream through the gap G to the port  256  in the housing  202 . Foam seals and O-ring seals have been used to seal the gap G, however, these seals exhibit the problems previously described. An overmolded seal having ribs may be provided on shutter  302  and be used to provide an effective seal while having a reduced frictional contact area with the housing allowing for lower torque to operate the shutter  302 . Overmolded seal  350  is used to seal the space  255  between shutter body  303  and the enclosed portion  254  of channel  250  to prevent the leakage of toner around exit port  256 . 
     Referring again to  FIGS. 2-4 , a shutter assembly  500  similar to shutter assembly  300  may also be used in the developer unit  400 . The developer unit  400 , illustrated in a partially assembled state in  FIG. 4 , comprises a housing  402  having a toner sump  404  formed by a rear wall  406 , first and second side walls  408 ,  410  and bottom  412 . A developer roll  420 , doctor blade  422  and toner adder roll are mounted between first and second side walls  408 ,  410 . The doctor blade  422  provides a metered uniform layer of toner on the surface of developer roll  420 . The developer roll  420  and doctor blade  422  enclose the toner sump  404 . A cooling duct  423  is positioned in front of doctor blade  422  and atop developer roll  420 . Duct  423  has nozzles at each end directed at the ends of the developer roller and its seals and provides cooling to the seals. A drive gear  424  is provided on one end of developer roll  420 . The toner adder roll which is hidden behind the doctor blade  422  is driven by gear  426 . An auger  430  having first and second ends  432 ,  434 , and a spiral screw flight  436  is received within a channel  450  extending along the width of rear wall  408  near the top of rear wall  408 . A first end  432  of the auger  430  extends through first side wall  408  and a drive connection  438  is provided to rotate auger  430 . Drive gears  424  and  426  receives torque from the imaging apparatus. The cleaner unit  600 , which would be in front of the developer unit  400 , and frame  800  are not shown. 
     A channel  450  for delivery toner from an entry port  456  (see  FIG. 2 ) comprises an open portion  452  and an enclosed portion  454 . Open portion  452  is open to the toner sump  404  and extends from the first side wall  408  toward the second end  434  of auger  430 . Enclosed portion  454  of channel  450  extends from the second side wall  410  and encloses a shutter  502  of shutter assembly  500 , the second end  434  of the auger  430  and is in fluid communication with the entry port  456 . Auger  430  is rotated via drive gear  438  to deliver toner received in shutter  502  into the open portion  452  of channel  450  and then into toner sump  404 . Shutter  502  rotates between a first position where it closes entry port  456  and a second position where entry port  456  is open. As illustrated entry port  456  is disposed at the top of channel  450  so that gravity will assist in having toner drop through entry port  456  and into the shutter. Shutter  502  is similarly constructed to shutter  302  except that the toner flow path is reversed from that in shutter  302 . For shutter  502 , toner drops through an exit opening in the wall of a hollow portion of the shutter  502  and into in a channel extending between the entry opening and an open end of the shutter. Toner and exits into channel  450  where auger  430  distributes the toner into the toner sump  404 . Shutter  502  is provided with an overmolded seal as previously described for shutter  302 . 
     Referring to  FIGS. 5-11 , an example overmolded seal  350  is shown overmolded onto body  303  of shutter  302 . In one form seal  350  is comprised of a sleeve  352  having one or more endless ribs  360  that is positioned upstream of the exit opening. The sleeve may extend along the length of the shutter body  303  and would have openings therethrough corresponding with the openings in the shutter body  303 . As illustrated, sleeve  352  would have opening  354  corresponding to exit opening  336  and first end  342  of duct  340  and other opening  356  corresponding to the second end  344  of duct  340  in shutter body  303 , if present. The ribs are “endless” because they are continuous and have no ends, joints or gaps. Ends, joints or gaps in these ribs are potential areas through which toner may leak. Endless ribs  360  are in one form generally circular or annular in a plane orthogonal to the rotational axis of the shutter body  303  but may follow other paths around the perimeter of the shutter body  303  or be on non-orthogonal planes to the rotational axis of the shutter body  303 . Sleeve  352  conforms to the shape of the surface of shutter body  303  and has a thickness TS that is less than the height of gap G. As illustrated in  FIG. 11 , the outer surface of shutter body  303  may be provided with one or more annular ribs  346 , and/or one or more axial ribs  347 . A rectangular windowpane grid is illustrated. Other scoring and grid patterns are a matter of design choice. The annular and axial ribs  346 ,  347  prevent the sleeve of seal  350  from slipping with respect to shutter body  303  during insertion into the housing and during operation of the shutter  302 . In the illustrated example, ribs  346 ,  347  are provided on hollow portion  314  of shutter body  303 . Grooves may also be scored into the surface of shutter body  303  and used in lieu of the ribs  346 ,  347  or in combination with them. Other forms of ribs and grooves may also be used such as a spiral rib or spiral groove alone or with the endless and axial ribs  346 ,  347 . The shape, spacing, and height or depth of the ribs and grooves is also a matter of design choice. 
     In one form, the overmolded seal  350  comprises a sleeve  352  having single endless rib  360  is positioned upstream of the exit opening  336  and downstream of the inner end  328  of the shutter body  303  and is used to block the flow of toner  10  along the potential leak path. Rib  360  has an upstream face UF and a downstream face DF. “Upstream” and “downstream” are relative to the direction of toner flow along a toner leak path. As one of skill in the art would recognize, the sleeve  352  of seal  350  shown in  FIG. 5  would be narrower and be provided upstream of exit opening  336 . As best seen in  FIG. 6 , the rib  360  projects outwardly at an angle from an outer surface of the sleeve  352 . Rib  360  has a height HR shown by the dashed outline of the tip of rib that is greater than the height of gap G within the space  255 . With shutter body  303  installed in the housing  202 , the tip T of rib  360  deflects by an amount D forming a sealing interface SI with the housing  202 , specifically the inner surface of the enclosed portion  254  of channel  250 . The effective sealing force may be controlled by the amount of deflection D and the resiliency of the material used in forming the endless and transverse ribs. For the shutter body  303  shown in  FIGS. 5-10 , sleeve  352  has openings  354 ,  356  therethrough. Opening  354  is disposed about both the first end  342  of duct  340  and exit opening  336  while opening  356  is disposed about second end  344  of duct  340 . As would be understood depending on the design of the sleeve and its coverage of the surface of the shutter body  303 , appropriate openings as required would be provided. 
     In another form, a second endless rib  362  may be provided downstream of exit opening  336 . Endless rib  362  may be angled oppositely from endless rib  360  as illustrated; however it may also be angled in the same manner as rib  360 . Rib  362  is also shown as having the same profile and height as rib  360 ; however, other heights and profiles may be used to provide a different sealing force than that applied by rib  360 . Further one or more gusset ribs  380  may be provided between a face on each endless ribs  360 ,  362  and sleeve  350  to inhibit the endless ribs  360 ,  362  from rolling or turning during insertion and operation of the shutter. 
     Also shown in  FIGS. 7-10  are transverse or axial ribs oriented general along the axis of rotation of the shutter body  303 . A first angled transverse rib  370  is positioned between and joined with endless ribs  360  and  362  adjacent exit opening  336  and the first end  342  of duct  340 . A second transverse rib  372  is positioned between and joined with endless ribs  360  and  362  adjacent exit opening  336  and the first end  342  of duct  340  but opposite first transverse rib  370  and is angled oppositely to first transverse rib  370 . Transverse ribs  370 ,  372 , along with the portions of endless ribs  360 ,  362  therebetween, surround exit opening  336  and the first end  342  of duct  340 . Because the amount of rotational travel of the shutter body  303  is limited by stop  310 , transverse ribs are not provided around the second end  344  of duct  340 . However providing additional transverse ribs about the second end  344  of duct  340  would be a matter of design choice. 
     Second transverse rib  372  may be angled oppositely from first transverse rib  370  as illustrated; however it may also be angled in the same manner as first transverse rib  370 . Second transverse rib  372  is also shown as having the same profile and height as first transverse rib  370 ; however, other heights and profiles may be used to provide a different sealing force than that applied by first transverse rib  370 . Further one or more gusset ribs  380  may be provided between each of first and second transverse ribs  370 ,  372  and sleeve  352  inhibit these transverse ribs from rolling or turning during insertion and operation of the shutter  302 . Because transverse ribs  370 ,  372  are molded as part of seal  350 , they are formed integrally with endless ribs  360 ,  362  so there are no gaps between the ends of the transverse ribs where they meet the endless ribs  360 ,  362 . 
       FIGS. 12 and 13  illustrate a further example embodiment of a shutter and overmolded seal. Like reference numerals will be used for like elements. For shutter  302 - 1 , sleeve  352 - 1  has an opening  354 - 1 . Opening  354 - 1  is disposed about exit opening  336 - 1 . Again, depending on the design of the sleeve and shutter body  303 - 1  and its coverage of the surface of the shutter body  303 - 1 , appropriate openings as required would be provided. Shutter body  303 - 1  has a drive portion  312 - 1  and a hollow portion  314 - 1 . Hollow portion  314 - 1  extends from an inner end  328 - 1  of the shutter  302 - 1  toward an outer end  330 - 1  and has [[a]] an open end  332 - 1  and a closed end  334 - 1 . Open end  332 - 1  and hollow portion  314 - 1  are sized to rotatably receive an end of the auger and provide support for the auger. Exit opening  336 - 1  is provided through a wall  333 - 1  of hollow portion  314 - 1 . A channel  337 - 1  is formed in shutter  302 - 1  between the open end  332 - 1  and exit opening  336 - 1  through which exiting toner passes on its way to an exit port. Shutter body  303 - 1  may be cylindrical or may taper slightly inwardly along the hollow portion  314 - 1 . 
     Overmolded seal  350 - 1  comprises a sleeve  352 - 1  having first and second single endless ribs  360 - 1 ,  362 - 1  that is positioned upstream and downstream respectively of the exit opening  336 - 1  and is used to block the flow of toner  10  along the potential leak path previously discussed. Endless ribs  360 - 1 ,  362 - 1  project outwardly at an angle from an outer surface of the sleeve  352 - 1 . Second endless rib  362 - 1  may be angled oppositely from rib  360 - 1  as illustrated; however it may also be angled in the same manner as rib  360 - 1 . Rib  362 - 1  is also shown as having the same profile and height as rib  360 - 1 ; however, other heights and profiles may be used to provide a different sealing force than that applied by rib  360 - 1 . One or more gusset ribs  380 - 1  may be provided between each ribs  360 - 1 ,  362 - 1  and sleeve  350 - 1  to inhibit the ribs from rolling or turning during insertion and operation of the shutter. 
     A first angled transverse rib  370 - 1  may be positioned between and joined with endless ribs  360 - 1  and  362 - 2  adjacent exit opening  336 - 1 . A second transverse rib  372 - 1  may be positioned between and joined with endless ribs  360 - 1  and  362 - 1  adjacent exit opening  336 - 1  but opposite first transverse rib  370 - 1  and is angled oppositely to first transverse rib  370 - 1 . Transverse ribs  370 - 1 ,  372 - 1 , along with the portions of endless ribs  360 - 1 ,  362 - 1  therebetween, surround exit opening  336 - 1 . Second transverse rib  372 - 1  may be angled oppositely from first transverse rib  370 - 1  as illustrated; however it may also be angled in the same manner as first transverse rib  370 - 1 . Second transverse rib  372 - 1  is also shown as having the same profile and height as first transverse rib  370 - 1 ; however, other heights and profiles may be used to provide a different sealing force than that applied by first transverse rib  370 - 1 . Further one or more gusset ribs  380 - 1  may be provided between each of first and second transverse ribs  370 - 1 ,  372 - 1  and sleeve  352 - 1  to inhibit these transverse ribs from rolling or turning during insertion and operation of the shutter  302 - 1 . 
     Because the endless ribs, and transverse ribs, if used, deflect rather than being compressed between the shutter body and the housing, the rotational frictional force for the deflected ribs is less than that for compressed form or O-rings. In one example configuration, the gap G may be in the range or 0.5 mm to about 3 mm with a nominal value of about 1.175 mm. The height HR of ribs  360 ,  362 ,  370 ,  372  may be in the range of 0.05 mm to about 1 mm with a nominal value of about 0.3 mm while the thickness TS of the sleeve  352  may be in the range of 0.1 mm to about 1.5 mm with a nominal value of about 0.5 mm. The amount of deflection D of the ribs  360 ,  362 ,  370 ,  372 , is in the range of 0.05 mm to about 1 mm with a nominal value of about 0.25 mm. As can be appreciated, the shutter body  303  is closely fitted in the enclosed portion  254  of channel  250 . 
       FIGS. 14-18  illustrate various configurations for the endless ribs.  FIG. 14  illustrates a sleeve  352 A having a single rib  360 A.  FIG. 15  illustrates a sleeve  352 B having a pair of similarly angled ribs  360 B,  360 C positioned together to form a double seal such as upstream of the exit opening.  FIG. 16  illustrates a sleeve  352 C having a pair of ribs  360 D,  360 E angled in the same direction; however rib  360 E has a greater height and more acute angle than rib  360 D. Ribs  360 D,  360 E are positioned together to form a double seal.  FIG. 17  illustrates a sleeve  352 D having two pairs of ribs  360 F,  360 G and  362 A,  362 B. Rib pair  360 F,  360 G are identical and angled in the same direction while rib pair  362 A,  362 B are identical and angled oppositely to rib pair  360 F,  360 G. Rib pair  360 F,  360 G may be positioned together to form a double seal upstream of the exit opening while rib pair  362 A,  362 B may be positioned downstream of an exit opening.  FIG. 18  illustrates a sleeve  352 E having two pairs of ribs  360 H,  360 J and  362 C,  362 D. Rib pair  360 H,  360 J are angled in the same direction however rib  360 J has a greater height and more acute angle than rib  360 H. Rib pair  362 C,  362 D are angled oppositely to rib pair  360 H,  360 J. Rib  362 C has a greater height and more acute angle than rib  362 D. Rib pair  360 H,  360 J may form a double seal upstream of the exit opening while rib pair  362 C,  362 D may be positioned downstream of an exit opening. These endless rib configurations are not meant to be limiting and other configurations of the endless ribs may be employed as one of ordinary skill in the art would recognize. 
     Referring to  FIGS. 19-22 , various example rib profiles are illustrated. These profiles may be used with the endless and transverse ribs previously discussed. Further the fibs rib profiles used in molding each of the endless and transverse ribs may be the same or each may be different.  FIG. 19  illustrates a rib profile wherein the opposite faces F 1 , F 2  are slightly curved or C-shaped and the faces taper inwardly from the root R at the sleeve to the tip T, with tip T being rounded.  FIG. 20  illustrates a rib profile wherein face F 1  tapers inwardly from root R in a generally linear fashion while face F 2  tapers inwardly in a slightly curved manner from root R with tip T being rounded and more bulbous and having a diameter  80  that is greater than the thickness  81  of the rib immediately adjacent the tip T.  FIG. 21  illustrates a rib profile wherein the opposite faces F 1 , F 2  are slightly curved in an S-shape and the faces taper inwardly from the root R at the sleeve to the tip T, with tip T being rounded.  FIG. 22  illustrates a rib profile wherein face F 1  tapers inwardly from root R in a generally linear fashion while face F 2  tapers inwardly in an S-shaped fashion from root R with tip T being rounded and more bulbous similar to the tip shown in  FIG. 20 . By using different rib profiles the magnitude of the seal force at the sealing interface and the shape and extent of the sealing interface between the rib tip and the wall of the housing in which the shutter body is inserted may be controlled. 
     Because the endless and transverse ribs are made using an overmolding process as is known to those of skill in the art, the features of the ribs as well as those of the sleeve in the overmolded seal may be more precisely controlled and positioned than is possible with the prior art foam seals. The acute angle to which the endless and transverse ribs are molded onto the sleeve may be between 10 to less than 90 degrees including all values and increments therein so that the ribs may deflect as described rather than being compressed between the shutter and the surrounding housing which occurs with foam and o-ring seals of the prior art. 
     Material suitable for forming the overmolded sleeve and ribs include thermoplastic elastomers (TPE), thermoplastic urethanes, thermoplastic vulcanizates such as SANTOPRENE®, or castable, injection molded or compression molded silicon rubber. 
     While the foregoing example embodiments of the overmolded shutter have been described as having entry or exit ports, such nomenclature is used only for descriptive purposes and is not intended to be limiting. Further, while the example overmolded shutters are described as having an open end, it should be realized that other configurations of channels for the passage of toner through the shutter body may also be used. 
     The foregoing description of several methods and an embodiment 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.