Abstract:
A container for flowable materials includes a first chamber storing flowable material within the container. A second chamber is separated from the first chamber within the container and contains a stirrer. A metering mechanism permits selective transfer of flowable material from the first chamber to the second chamber.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates generally to the storage and dispensing of consumables in imaging systems. Specifically, the invention relates to the storage of toner within hoppers in cartridges in electrostatic printing (EP) imaging systems.  
         BACKGROUND OF THE INVENTION  
         [0002]    Imaging systems such as printers, fax machines, and copiers are virtually omnipresent, and can be found in homes and offices worldwide. The development of such systems has facilitated improvements in communications that have in turn fostered profound changes in the ways that people live and work. Telecommuting, “virtual” offices, and intra-office networks represent but a few examples of the advancements that have been made possible by modern imaging systems.  
           [0003]    Imaging systems using electrostatic printing have found wide acceptance. In electrostatic printing, toner stored in a hopper is deposited on a media sheet, then heat-fused to the media sheet. Within the hopper are stirrers to maintain the toner in particulate form by preventing coalescing, or “clumping”, of the toner. Stirrers also serve to transfer toner towards the developer drum, and create a dusting of toner to assist the developer roller in attracting toner particles to the developer roller surface.  
           [0004]    One example of hopper stirrer arrangements is set forth in U.S. Pat. No. 5,854,961 to Hoberock, which is directed to a toner delivery and metering apparatus including a generally U-shaped or trough member which is operative to receive toner material. The dry, non-magnetic toner particles are agitated and stirred with an oscillating or rotating stirrer blade and passed between the sidewalls of a toner supply rod. The toner supply rod is rotatably mounted in the bottom of the trough member, and is operative to pass the toner particles onto the surface of the applicator and charging roller by controlled oscillatory and agitating motion at the lower opening within the trough member.  
           [0005]    Typical color toner particles are comprised of EP-enhancing particulates bonded to the surface of colorized polymers. Since mechanical stirrers contact particles that remain in the hopper as well as those that are transferred, particles within the hopper can be subjected to repeated and unnecessary contact with the stirrer elements. The particulate/polymer bonds can become damaged by contact with the mechanical stirrers, thus causing the toner to act inconsistently with the EP process. This inconsistency degrades print quality, and shortens the life of the cartridge/toner.  
           [0006]    In an attempt to reduce stirrer/particulate contact, hoppers have been developed in which a primary stirrer in contact with most of the toner is used infrequently, while a smaller, secondary stirrer operates constantly in a conventional manner.  
           [0007]    While known “two-level” stirring reduces particulate damage somewhat, such arrangements still cause unnecessary particulate damage due to constant stirrer/particulate contact. It can be seen from the foregoing that the need exists for a simple, inexpensive, arrangement for minimizing particulate damage in toner hoppers.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention is directed to a container for flowable materials including a first chamber storing flowable material within the container. A second chamber is separated from the first chamber within the container and contains a stirrer. A metering mechanism permits selective transfer of flowable material from the first chamber to the second chamber. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a schematic sectional view of a container in accordance with the principles of the present invention.  
         [0010]    [0010]FIG. 2 is a schematic sectional view of an alternative embodiment of a container in accordance with the principles of the present invention.  
         [0011]    [0011]FIG. 3 is a schematic sectional view of an alternative embodiment of a container in accordance with the principles of the present invention.  
         [0012]    [0012]FIG. 4 is a schematic sectional view of an alternative embodiment of a container in-accordance with the principles of the present invention.  
         [0013]    [0013]FIG. 5 is a schematic sectional view of an alternative embodiment of a container in accordance with the principles of the present invention.  
         [0014]    [0014]FIG. 6 is a schematic sectional view of an alternative embodiment of a container in accordance with the principles of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]    An embodiment of a container  10  in accordance with the principles of the present invention is shown in FIG. 1. The container  10  is adapted and constructed to hold a predetermined quantity of consumable flowable material, such as toner  12 , for use in an imaging system (not shown).  
         [0016]    An angled partition  14  divides the interior of the container  10  into a first, storage chamber  16 , and a second, distribution chamber  18 . A distribution mechanism, such as a charging roller  20 , is located within the distribution chamber  18 . The charging roller  20  receives toner from within the distribution  18 , and distributes it to an EP drum  22  for transfer to imaging sheet material. A stirrer  24  rotates within a stirrer well  26  to facilitate uniform distribution of the toner  12 .  
         [0017]    A metering mechanism  28  is provided between the storage chamber  16  and the distribution chamber  18 . The metering mechanism  28  selectively regulates the amount of toner  12  flowing from the storage chamber  16  to the distribution chamber  18 . In the FIG. 1 embodiment, the metering mechanism  28  takes the form of an opening  30  between the partition  14  and an outer wall  32  of the container  10  sized to restrict the flow of toner  12  between the storage chamber  16  and the distribution chamber  18 . Toner  12  is gravity-fed through the opening  30  to the stirrer well  26  to supply toner on demand. Rotation of the stirrer  24  causes excess toner to be “splashed” back to the outside of the stirrer well  26 , thus permitting an appropriate amount of toner to flow freely to the stirrer  26 .  
         [0018]    An alternative embodiment of a container  34  incorporating the principles of the present invention is shown in FIG. 2. The interior of the container  34  is divided into-a first, storage chamber  36 , and a second, distribution chamber  38 . A distribution mechanism, such as a charging roller  40 , is located within the distribution chamber  38 . The charging roller  40  receives toner from within the distribution  38 , and distributes it to the EP drum  42  for transfer to imaging sheet material. A stirrer  44  rotates within a stirrer well  46  to facilitate uniform distribution of toner  48  within the distribution chamber  38 , and to deliver toner to the charging roller  40 .  
         [0019]    The storage chamber  36  is divided into a plurality of storage sub-chambers  36 A,  36 B. The storage sub-chambers  36 A,  36 B are formed by a series of selectively opening closure members  50 A,  50 B within the storage chamber  36 . The closure members  50 A,  50 B are shown in the form of removable partitions. It is also contemplated that the closure members  50 A,  50 B could be provided as “hoppers” with angled bottoms sloping downwardly to a selectively actuated opening or openings. Irrespective of their specific construction, the closure members form a metering mechanism capable of serially supplying fresh (not mechanically agitated) “batches” of toner to the distribution chamber  38 , so that only one zone of toner is in process at a given time. In practice, when the container is originally installed, the distribution chamber is provided with an initial charge  52  of toner. When a trigger event has occurred, e.g., depletion of the charge  52  or a predetermined number of images have been processed by the imaging system, the closure member  50 A opens, thus allowing a charge  54  of toner contained within the sub-chamber  36 A to flow into the distribution chamber  38 . Similarly, once when a second trigger event has occurred, e.g., depletion of the charge  54  or an additional predetermined number of images have been processed by the imaging system, the closure member  50 B opens, thus allowing a charge  56  of toner contained within the sub-chamber  36 B to flow into the distribution chamber  38 .  
         [0020]    Yet another embodiment of a container  60  in accordance with the principles of the present invention is shown in FIG. 3. The container  60  is adapted and constructed to hold a predetermined quantity of consumable flowable material, such as toner  62 , for use in an imaging system (not shown).  
         [0021]    An angled partition  64  divides the interior of the container  60  into a first, storage chamber  66 , and a second, distribution chamber  68 . A distribution mechanism, such as a charging roller  70 , is located within the distribution chamber  68 . The charging roller  70  receives toner from within the distribution  68 , and distributes it to an EP drum  72  for transfer to imaging sheet material. A stirrer  74  rotates within a stirrer well  76  to facilitate uniform distribution of the toner  62 .  
         [0022]    A metering mechanism  78  is provided between the storage chamber  66  and the distribution chamber  68 . The metering mechanism  78  selectively regulates the amount of toner  62  flowing from the storage chamber  66  to the distribution chamber  68 . In the FIG. 3 embodiment, the metering mechanism  78  takes the form of a paddle wheel  80  located in an opening  82  between the partition  64  and an outer wall  84  of the container  60 . The paddle wheel  80  rotates to meter individual charges or loads of toner into the distribution chamber  68 . The paddle wheel  80  can be stopped at “closed” increments to minimize leaking during removal, installation, and transport of the container  60 . It is also contemplated that an alternative incremental feed mechanism, such as an auger, could be located and operated in a similar manner.  
         [0023]    Another alternative embodiment of a container  86  incorporating the principles of the present invention is shown in FIG. 4. The interior of the container  86  is divided into a first, storage chamber  88 , and a second, distribution chamber  90 . A distribution mechanism, such as a charging roller  92 , is located within the distribution chamber  90 . The charging roller  92  receives toner from within the distribution  90 , and distributes it to the EP drum  94  for transfer to imaging sheet material. A stirrer  96  rotates within a stirrer well  98  to facilitate uniform distribution of toner  100  within the distribution chamber  90 , and to deliver toner to the charging roller  92 .  
         [0024]    The storage chamber  88  is divided into a plurality of storage sub-chambers  88 A,  88 B,  88 C,  88 D. The storage sub-chambers  88 A,  88 B,  88 C,  88 D are formed by a series of dividers  102 A,  102 B,  102 C within the storage chamber  88 . A selectively retractable closure membrane  104  seals the bottoms of the storage sub-chambers  88 A,  88 B,  88 C,  88 D. A retraction mechanism, such as a take-up roller assembly  106 , is connected to the membrane  104 . The retraction mechanism is adapted to selectively remove the membrane  104  from the respective bottoms of the storage sub-chambers  88 A,  88 B,  88 C,  88 D to serially supply fresh (not mechanically agitated) “batches” of toner to the distribution chamber  90 , so that only one zone of toner is in process at a given time. It is contemplated that the retraction mechanism will be actuated through the control mechanism of the imaging system, either electronically, or mechanically by being slaved to the gear train via a reduction gear.  
         [0025]    Another alternative embodiment of a container  108  incorporating the principles of the present invention is shown in FIG. 5. The interior of the container  108  is divided into a first, storage chamber  110 , and a second, distribution chamber  112 . Distribution mechanisms and including a charging roller, EP drum, and stirrer are provided as previously described.  
         [0026]    The storage chamber  110  is separated from the distribution chamber  112  by a selectively opening closure member  114 . The closure member  114  reciprocates horizontally, thus supplying fresh (not mechanically agitated) “batches” of toner to the distribution chamber  112 , so that only a limited amount of toner is in process at a given time. When a trigger event has occurred, the closure member  114  briefly opens, thus allowing a predetermined amount of toner to flow into the distribution chamber  112 .  
         [0027]    Yet another embodiment of a container  116  in accordance with the principles of the present invention is shown in FIG. 6. The interior of the container  116  is divided into a first, storage chamber  118 , and a second, distribution chamber  120 . Distribution mechanisms and including a charging roller, EP drum, and stirrer are provided as previously described.  
         [0028]    The storage chamber  118  is separated into a plurality of sub-chambers  118 A,  118 B,  118 D by a rotatable divider  122 . The divider  122  includes a plurality of divider  124 A,  124 B,  124 C,  124 D extending radially from a central hub  126 . As toner is consumed, the divider  122  is selectively incrementally rotated to dispense the contents of the respective chambers into a holding chamber  128 .  
         [0029]    A metering mechanism  130  is provided between the holding chamber  128  and the distribution chamber  120 . The metering mechanism  130  takes the form of a paddle wheel  132  located in an opening  134  between the holding chamber  128  and the distribution chamber  120 . The paddle wheel  132  rotates to meter individual chargers or loads of toner into the distribution chamber  120 . The paddle wheel  132  can be stopped at “closed” increments to minimize leaking during removal, installation, and transport of the container  116 . It is also contemplated that an alternative incremental feed mechanism, such as an auger, could be located and operated in a similiar manner.  
         [0030]    The present invention isolates discrete quantities of flowable material for on-demand delivery to a distribution mechanism. Although the present invention has been described with reference to specific embodiments, those of skill in the art will recognize that changes may be made thereto without departing from the scope and spirit of the invention as defined by the appended claims.