Patent Publication Number: US-2004050448-A1

Title: Toner filling apparatus including an anti-dribbling nozzle having air discharge ports

Description:
RELATED APPLICATION  
     [0001] This application has the same inventor as, and is a Divisional of, U.S. application Ser. No. 10/198,398 filed on Jul. 17, 2002. 
    
    
     
       BACKGROUND OF THE INVENTION  
       [0002] This invention relates generally to apparatus for filling a container with dry particulate material, and more particularly concerns a filling apparatus including an anti-dribbling filling nozzle having slanted air discharge ports for achieving dribble-free, clean-cutoff filling of a container with particulate materials such as toner.  
       [0003] Currently when filling particulate materials, for example toners into toner containers, toner is transported from the toner supply hopper into the container by a rotating auger. The auger is a spiral shaped mechanical part which pushes particles of toner inside a fill tube by direct mechanical contact. The nature of this mechanical contact process creates substantial limitations on accuracy and productivity of the toner filling operation. The speed of the toner movement in the fill tube is proportional to the speed of rotation of the auger and is limited by heat release due to auger/toner/funnel friction.  
       [0004] Toner containers for small low cost printers and copiers typically have a small opening into which the toner is to be added. Furthermore, the toner containers often have irregular shapes to conform to the allotted space within the copying machine. Therefore it becomes difficult to fill the toner container because of the small tube or nozzle required to fit into the small toner container opening and secondly for all the toner within the container to completely and cleanly fill the remote portions of the container before the container overflows.  
       [0005] In addition, during the filling operation there is some ordinarily undesirable continued discharge of toner (dribbling) from a conventional nozzle at cutoff or at the end of the filling cycle. In one embodiment, the end of a filling cycle occurs when the auger stops rotating and positive pressure normal to the axis of the auger is kept on for a fraction of a second longer in order to give some time for the toner or powder remaining in the nozzle to drop into the container. After that, the positive pressure is cut off and negative pressure in the form of a vacuum is turned on to “freeze” against the nozzle wall, any toner particles still remaining in the nozzle.  
       [0006] The main problem with this process is that when the positive pressure in the nozzle is switched to vacuum, this vacuum usually can firmly hold only a 3-5 mm thick layer of toner particles against the inner nozzle wall. Therefore in cases where the amount of toner remaining inside the nozzle is sufficient to create a layer thicker than 5 mm, the force of vacuum will be marginal (weak) for holding those toner particles on the top of the 5 mm layer surface. Thus, very often this force is not enough to hold them for more than 0.5-1 sec. Therefore, undesirable post-cutoff continued toner fallout or dribbling occurs when the filling apparatus indexes from one container to the next, thus resulting in dirty tops and/or sides of containers.  
       [0007] Conventional filling apparatus include conventional clean filling systems for use with such apparatus. Such a clean filling system is secured to filling line as well as to the toner conduit, and may be used to support a slide. The slide is connected to a tray or toner drip plate which slidably is fitted between the nozzle and the opening. A tray or drip plate in this position acts to prevent the spilling of powder during the indexing of containers. A housing which surrounds part of the nozzle, provides a cavity or chamber which is sealed when the tray or drip plate is in its closed position.  
       SUMMARY OF THE INVENTION  
       [0008] In accordance with the present invention, there is provided a method and apparatus for directing toner from a hopper containing a supply of toner to fill as well as cleanly cutoff filling of a container without post-cutoff dribbling. The apparatus includes (a) a conduit member connected to the hopper and having a discharging end for permitting a toner to be moved therethrough; (b) a conveyor device located at least partially within the conduit member for moving the toner from the hopper in a toner moving direction towards the container; and (c) an anti-dribbling nozzle device for directing the toner from the conveyor to cleanly fill the container. The anti-dribbling nozzle device includes a source of pressurized air, a controller, and a nozzle member that has a first end connected to the discharge end of the conduit member, a second and opposite end for dispensing moving toner into the container, and a nozzle wall connecting the first end to the second thereof. The nozzle wall includes slanted air discharging ports for discharging directed pulses of positive pressure air to forcibly remove powder from the nozzle wall, thereby enabling clean cutoff of powder flowing into the container without post-cutoff dribbling. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] In the detailed description of the invention presented below, reference is made to the drawings in which:  
     [0010]FIG. 1 is an elevational view of a toner container filling apparatus partially in section utilizing an anti-dribbling nozzle device having the slanted air discharge ports in accordance with the present invention;  
     [0011]FIG. 2 is an elevational view of an enlarged portion of the filling apparatus of FIG. 1 showing the anti-dribbling nozzle device having the slanted air discharge ports in accordance with the present invention;  
     [0012]FIG. 3 is an elevational view of the anti-dribbling nozzle device of FIG. 2 during container filling;  
     [0013]FIG. 4 is an elevational view of the anti-dribbling nozzle device of FIG. 2 during cutoff of container filling; and  
     [0014]FIG. 5 is an elevational view of the anti-dribbling nozzle device of FIG. 2 post-cutoff showing a clean cutoff without dribbling in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0015] While the present invention will be described in connection with a preferred embodiment thereof, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.  
     [0016] According to the present invention and referring now to FIG. 1, powder filling apparatus  10  is shown. The powder filling apparatus  10  is used to convey powder  12  in the form of toner for use in a copier or printer from a hopper  14  to a container  16 . The powder filling apparatus  10  is mounted to filling line  20  to permit for the filling of large production quantities of containers  16 , the container  16  is mounted to a carrying device  22 . The device  22  is movable in the direction of either arrow  24  or  26 . The carrying device  22  serves to position container centerline  30  in alignment with apparatus centerline  32 .  
     [0017] The powder filling apparatus  10  includes an anti-dribbling nozzle  34  (in accordance with the present invention, and to be described in detail below) which is used to direct the powder  12  into the container  16 . The anti-dribbling nozzle  34  is connected to the hopper  14  by means of a conduit  36  in the form of a hollow tube or funnel. As shown in FIG. 1, the hopper  14  is positioned above the container  16  whereby gravity will assist in the flow of powder  12  toward the container  16 . To optimize the flow of powder  12  toward the container  16 , the powder filling apparatus  10  further includes a conveyor  40  positioned at least partially within the conduit  36  for assisting in the flow of the powder  12 . The conveyor  40  is in the form of a spiral conveyor or auger. For example, the auger  40  may be in the form of a spiral shaped auger, which may include various geometries, such as, a straight or tapered helical screw. The auger closely conforms to the conduit.  
     [0018] The anti-dribbling nozzle  34  is insertable into opening  42  of the container  16 . The insertion of the anti-dribbling nozzle  34  in the opening  42  may be accomplished in any suitable method. For example, the carrying device  22  and, consequently, the container  16  may be movable upward in the direction of arrow  44  for engagement with the anti-dribbling nozzle  34  and downward in the direction of arrow  46  for disengagement from the opening  42 . The upward and downward motion of the device  22  and the container  16  permits the container  16  to be indexed in the direction of arrows  24  and  26 .  
     [0019] To permit the filling of a number of containers  16 , the flow of powder  12  from the hopper  14  must be halted by cutting off filling or powder flow, during the indexing of a filled container  16  from the fill position and during the indexing of the unfilled container  16  toward the filling position. In accordance with the present invention, it is important that halting powder flow by cutting off filling or powder flow be achieved cleanly without significant or any post-cutoff continued flow or dribbling.  
     [0020] As shown in FIG. 1, the auger  40  may be rotated by any suitable method, i.e. by motor  50  connected to the auger  40  for rotating the auger  40  in a direction  53 . The motor  50  is connected to a controller  52  which sends a signal to the motor  50  to stop the rotation of the auger  40  during indexing of the carrying device  22 . The controller  52  is also connected by means  54  to the source  66  of pressurized air for varying the application of positive air pressure from a uniform pressure  68  to short bursts of higher pressure air  70 . Accordingly, the primary flow of powder  12  is halted by the stopping of auger  40  within the conduit  36  and by the use of a valve therein (not shown). A housing  56  which surrounds part of the anti-dribbling nozzle  34 , provides a cavity or chamber  62  which is sealed when the discharge opening  94  of the nozzle  34  is closed by suitable means (not shown). The chamber  62  can be pressurized or kept under vacuum via an air pressure applying device  64  that can apply uniform positive pressure  68  (FIGS. 2 and 3) as during a filling cycle, short bursts of higher positive pressure  70  for dribble-free cutoff in accordance with the present invention, or negative pressure  69  (FIGS. 4 and 5) post-cutoff. As shown in FIG. 1, the device  64  can also be a toner dust vacuum line  64  to an air pressure and vacuum source  66 .  
     [0021] Referring now to FIGS.  1 - 2 , the anti-dribbling nozzle  34  is shown in greater detail and includes a first end  90  adjacent to and mounted to the conduit  36 , as well as a second end  92  opposed to the first end  90 . The anti-dribbling nozzle  34  is comprised of a wall  96  and is secured to the conduit  36  in any suitable fashion. For example, as shown the first end  90  of the anti-dribbling nozzle  34  may be press fitted over the conduit  36  and is rigidly located within the housing  56 . Between the first end  90  and the second end  92  of the anti-dribbling nozzle  34  is a central portion  93  of the nozzle. The central portion  93  has a hollow substantially conofrustrical shape or funnel like shape. As shown, the second or discharge end  92  includes a discharge opening  94  defined by the wall  96 .  
     [0022] Thus to recap, in accordance with the present invention, there is disclosed an apparatus  10  for directing powder  12  from a hopper  14  containing a supply of powder to fill as well as cleanly cutoff filling of a container  16  without post-cutoff dribbling. The apparatus  10  includes (a) a conduit member  36  connected to the hopper and having a discharging end for permitting a quantity of powder to be moved therethrough; (b) a conveyor device  40  located at least partially within the conduit member for moving the quantity of powder from the hopper in a powder moving direction; and (c) an anti-dribbling nozzle assembly  100  for directing a quantity  114  of powder from the conveyor device to cleanly fill the container  16 .  
     [0023] The anti-dribbling nozzle assembly  100  includes a source  64  of pressurized air, a controller  52  and a nozzle member  34  having a first end  90  connected to the discharge end of the conduit member  36 , a second and opposite end  92  for dispensing moving powder into the container, and a nozzle wall  96  connecting the first end to the second end. The nozzle wall  96  includes slanted air discharge ports  110  for selectively discharging directed pulses  70  of positive pressure air to forcibly remove powder from the nozzle wall  96 , thereby enabling clean cutoff of powder flowing into the container without post-cutoff dribbling. In one embodiment as shown, the nozzle wall  96  is porous to air so that uniform relatively lower pressure air can penetrate from the cavity  62  outside the wall  96  through random pores within the wall  96 , and in a direction normal to the axis of the nozzle (FIG. 3) into the inside of the wall  96 , thereby reducing friction between flowing powder or toner and the inside of the wall.  
     [0024] As further shown, the slanted air discharge ports  110  are located uniformly around the nozzle wall  96  and between the first end  90  and the second  92  thereof. The slanted air discharge ports  110  are each slanted forwardly relative to a direction of powder flow into the container. The slanted air discharge ports each form an angle of less than 15 degrees with the wall. The integration of the slanted or angled air discharge ports  110  into the body or wall  96  of the nozzle member  34  effectively provides an additional and timely force at the end of the cutoff cycle for pushing out the powder or toner  118  from the nozzle into the container  16 .  
     [0025] Further, with the means  66 ,  64 , for applying positive  68 ,  70  and negative  69  air pressure to the wall  96  of the nozzle member  34 , the method of cleanly cutting off filling of the container without post-cutoff dribbling of powder in accordance with the present invention includes (a) stopping rotation of the auger  40  for moving powder material from the hopper, and stopping application of uniform continuous positive pressure  68  to the wall  96  of the nozzle member  34 ; (b) applying negative pressure  69  to the wall  96 ; (c) next applying increased short bursts  70  of positive air pressure through the slanted air discharge ports  110  in the wall for forcibly removing any powder from the nozzle wall; and (c) finally applying negative air pressure  69  again to the wall  96  following the step of applying increased short bursts  70  of positive air pressure. This thereby enables cleanly cutting off filling of the container  16  without post-cutoff dribbling of powder.  
     [0026] As can be seen, there has been provided a method and apparatus have been provided for directing toner from a hopper containing a supply of toner to fill as well as cleanly cutoff filling of a container without post-cutoff dribbling. The apparatus includes (a) a conduit member connected to the hopper and having a discharging end for permitting a toner to be moved therethrough; (b) a conveyor device located at least partially within the conduit member for moving the toner from the hopper in a toner moving direction towards the container; and (c) an anti-dribbling nozzle device for directing the toner from the conveyor to cleanly fill the container. The anti-dribbling nozzle device includes a source of pressurized air, a controller, and a nozzle member that has a first end connected to the discharge end of the conduit member, a second and opposite end for dispensing moving toner into the container, and a nozzle wall connecting the first end to the second thereof. The nozzle wall includes slanted air discharging ports for discharging directed pulses of positive pressure air to forcibly remove powder from the nozzle wall, thereby enabling clean cutoff of powder flowing into the container without post-cutoff dribbling.  
     [0027] While the embodiment disclosed herein is preferred, it will be appreciated from this teaching that various alternative, modifications, variations or improvements therein may be made by those skilled in the art, which are intended to be encompassed by the following claims: