Abstract:
Apparatus and methods for filling one or more containers with flowable material such as cereals, grain or rice. Flowable material is transferred via a material guide into filling stations. The material guide or the filling stations can be moved between a first position in which all the flowable material input is guided into the first container, and a second position in which all the flowable material input is guided into the second container. At intermediate positions between the first and second positions, the flowable material input is divided between the first and second containers. The proportion of flowable material entering each of the containers is varied to enable a nearly full container to be topped up to the desired level while maintaining control over the flow and at the same time rapidly filling another container. The filling stations, at which the containers are located, may be positioned in various configurations.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 09/673,062, filed Dec. 22, 2000, now abandoned which itself is a §371 application of International Application No. PCT/AU99/00266, filed on Apr. 9, 1999, which itself claimed the benefit of Australian Application No. PP2937, filed on Apr. 9, 1998. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a filling apparatus and more particularly to a filling apparatus capable of continuous, sequential filling of a plurality of containers. 
     BACKGROUND ART 
     An apparatus of this type is used for filling containers, such as bags, with a predetermined weight of flowable material such as, for example, cereals, grain or rice. 
     An example of the Applicant&#39;s prior apparatus of this type is shown in Australian Patent No. 551762. This apparatus includes a chute which toggles under the influence of counterweights between directing all the flowable material input stream to a first container or to a second container. 
     A disadvantage of this prior art apparatus is that the speed of the flowable material must be limited so that the weighing apparatus can terminate the flow of material entering a container upon reaching its predetermined weight, with reasonable accuracy, notwithstanding inflight material and flow rate variations. 
     It is an object of the present invention to substantially overcome or at least ameliorate the disadvantages of the prior art devices and more particularly to provide a faster and more efficient filling arrangement. 
     It is a further object of the present invention to provide a filling arrangement capable of continuous, sequential filling of a plurality of containers. 
     SUMMARY OF THE INVENTION 
     Accordingly, in a first aspect, the present invention provides an apparatus for filling a plurality of containers with flowable material, the apparatus including: 
     a plurality of container filling stations arranged in a sequence; and a fixed flow divider located between one filling station and the next filling station in the sequence; and 
     a material guide for flow of flowable material, 
     wherein the apparatus includes means to move the material guide relative to the filling stations or vice versa so that the apparatus is capable of adopting: 
     a first rest position in which all the flow of flowable material is guided to one of the container filling stations; 
     an intermediate rest position in which the flow of flowable material is divided between the one container filling station and the next container filling station in the sequence; and 
     a second rest position in which the flow of flowable material is guided to the next container filling station. 
     The flowable material is preferably grain, cereal or rice. 
     There may be two or more container filling stations. When there are more than two filling stations, preferably these are arranged in a loop, such as a circle, so that containers may be filled in a continuous manner, one after the other. In this embodiment, movement of the material guide relative to the filling stations, or vice versa, can be effected in one direction only, with an empty container being placed at an appropriate filling station ahead of flow from the material guide reaching that filling station, and with filled containers being removed sequentially after filling. In this embodiment, it is preferred that the material guide is stationary and the filling stations travel past the material guide, by means of a conveyer belt, for example. 
     Alternately, the sequence of container filling stations may have a start and a finish point, rather than forming a loop. This, of course, will be the case if there are only two filling stations. Even with three or more filling stations, it is within the scope of this invention that, once the containers at the filling stations have been filled, the apparatus is designed to move back to the start point and repeat the performance. In this embodiment, while either the material guide or the filling stations may move, it is preferred that the filling stations remain stationary and the material guide moves. 
     Desirably, at the intermediate rest position 10% of the flow of flowable material is directed substantially to the one container filling station and 90% of the flow of flowable material is directed substantially to the next container filling station. 
     In one preferred embodiment, the material guide is a chute adapted to pivot about a substantially vertical axis between the first and second positions. The chute preferably includes an inclined base and two substantially vertical side walls. The base is preferably upwardly convex and includes corrugations for spreading the material flow across the width of the base. 
     In other embodiments, the material guide is a vibrating tray, or an auger fed nozzle which pivots in a substantially horizontal plane, or a gravity fed nozzle mounted beneath a flexible tube for pivoting in a substantially vertical plane. 
     The material guide may be, in fact, more than one guide, which can be useful when the flowable material has a tendency to stick together or to stick to the guide. If there is more than one material guide they may be controlled (see below) independently. For example, where there are two material guides, the first may direct a larger proportion of the flowable material while the second directs the remainder. 
     It is to be understood that the means moving the material guide relative to the filling stations, or moving the filling stations relative to the material guide, may be any suitable means, one of which is described in connection with an embodiment in the drawings, below. 
     The apparatus preferably includes weighing devices to weigh the amount of material in each of the containers. When it is the material guide which moves, the apparatus preferably also includes a control system adapted to cause moving of the material guide between the first, intermediate and second rest positions. In a sophisticated version of the invention, the control system causes such movement in response to the weight of material in each of the containers. 
     The control system (which may also be used when the filing stations move) may be pneumatically driven. It also preferably includes fine adjustment means capable of adjusting the portion of flow of flowable material into the first or next container to a fine degree. For example, in one embodiment, the fine adjustment may cause the input to be divided so that 99% flows into one container while 1% flows into the other. The fine adjustment means preferably takes the form of a wheel adapted to cause the chute to move in small increments towards the first or second container. 
     In a second aspect, the present invention provides a method for filling a plurality of containers using the apparatus of the invention, said method including the steps of: 
     (1) directing all of the flow of flowable material into a first container until it is filled to a first predetermined weight; 
     (2) directing a portion of the flow of flowable material into each of the first container and a second container adjacent the first container until the first container is substantially full; 
     (3) directing all of the flow of flowable material into the second container until it is filled to a second predetermined weight; 
     (4) directing a portion of the flow of flowable material into each of the second container and a third container adjacent the second container; and 
     (5) directing a portion of the flow of flowable material into each of the third and second containers until the second container is substantially full. 
     Preferably, steps (1) to (5) are repeated to continuously fill the plurality of containers until a predetermined number of containers is filled or the flow of flowable material is exhausted. The first and second predetermined weights are preferably substantially equal. Desirably, the flow at step (2) is directed 10% to the first container and 90% to the second container. At step (5) the flow is desirably directed 90%, 10% to the third and second containers respectively. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
     FIG. 1 is a side view of a filling apparatus according to a first embodiment of the invention with a movable material guide in the first position; 
     FIG. 2 is a front view of the apparatus shown in FIG. 1; 
     FIG. 3 is a side view of the apparatus shown in FIG. 1 with the material guide at an intermediate position between the first and second positions; 
     FIG. 4 is a front view of the apparatus shown in FIG. 3; 
     FIG. 5 is a side view of the apparatus shown in FIG. 1 with the material guide in the second position; 
     FIG. 6 is a front view of the apparatus shown in FIG. 5; 
     FIG. 7 is a perspective view of a material guide chute; 
     FIG. 8 is a partial end view of the chute of FIG. 7 along line  8 — 8 ; 
     FIG. 9 is a schematic view of a pneumatic circuit used to control the position of the chute shown in FIGS. 1 to  7 ; 
     FIG. 10 is a perspective view of the load cell arrangement of the apparatus shown in FIG. 1; 
     FIG. 11 is a perspective view of a filling apparatus according to a second embodiment of the invention; 
     FIGS. 12 a  to  12   f  are plan views of the apparatus of FIG. 11 with the material guide in various filling positions; 
     FIG. 13 is a perspective view of a filling apparatus according to a third embodiment of the invention; 
     FIG. 14 is a perspective view of a filling apparatus according to a fourth embodiment of the invention; 
     FIG. 15 is a cross-sectional side view of the auger of the embodiment of FIG. 14; 
     FIG. 16 is a front view of a fifth embodiment of the invention with a fixed material guide in the intermediate position, the filling stations being in a straight line; 
     FIG. 17 is a schematic front view of the apparatus of FIG. 16 with the material guide in the first position; 
     FIG. 18 is a schematic front view of the apparatus of FIG. 16 with the material guide in the intermediate position; 
     FIG. 19 is a front view of the apparatus of FIG. 16 with the material guide in the second position; and 
     FIG. 20 is a perspective view of a sixth embodiment of the invention, the material guide being fixed and the filling stations being in a loop. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 to  6 , there is shown a first embodiment of an apparatus  10  for filling a first container  12  and a second container  14  (each located at a filling station) with flowable material leaving the outlet  15  of, for example, an overhead hopper gravity feeding through a pneumatic gate valve, an auger driven by a variable speed electric motor or a vibratory feeder. 
     The apparatus  10  includes a movable material guide in the form of chute  16  which has a generally U-shaped cross section. The chute is best seen in FIGS. 7 and 8 and includes an inclined upwardly convex corrugated base  18  between two side wails  20 . The corrugations and convexity of the base  18  facilitate spreading of the flowable material evenly across the walls of the base  18 . The chute  16  is mounted at the top of a shaft  22  which is rotatable about a vertical axis  24 . 
     Each of the containers  12  and  14  is releasably mounted to respective weighing and bagging devices  26  and  28  respectively. Above each of the weighing and bagging devices  26  and  28  there is a pair of respective fixed material guides  30  and  32 . The guides  30  and  32  are attached to each other along a vertical edge  34  which is at the apex of two inner inclined side walls  36  and  38  respectively. 
     The chute  16  and the guides  30  and  32  are desirably manufactured from stainless steel for ease of cleaning and corrosion resistance. The chute  16  is adapted to be movable between a first position in which it directs all of the material input from the hopper through the first fixed guide  30  and into the first container  12 , as shown in FIG. 2, and a second position in which it directs all of the material through the second fixed guide  32  into the second container  14 , as shown in FIG.  6 . At intermediate positions between the two positions, the flowable material input is incident on the edge  34  and is partially directed through both the fixed guides  30  and  32  and thus divided between the first and second containers  12  and  14  respectively, as shown in FIG.  4 . 
     As FIG. 4 approximately indicates, the closer the chute  16  is to a first or second position, the greater proportion of the total available material flow is directed to the adjacent container  12  or  14 . This allows a very slow flow rate of material to be directed into a container which is nearly full for accurate final filling and weighing off whilst the larger remaining flow of material can be simultaneously filling another container, thereby increasing accuracy and reducing overall filling times. 
     As an example, the apparatus  10  can be configured such that the chute  16  will initially direct all of the material flow to the first container  12  until the weighing and bagging device  26  indicates that the container  12  is approximately 85% full. At this point, the chute  16  pivoted towards the second position to an intermediate position above the edge  34  where 10% of the overall material flow continues to fill the first container  12  and the remaining 90% of the flow commences to fill the second container  14 . When the first container  12  is 100% full, the chute  16  is moved to the second position and directs all of the material flow to the second container  14 . As the second container reaches 85% full, the chute  16  is pivoted to another intermediate position directing 10% of the flow to the second container  14  and the remaining 90% to a new and empty first container  12 . The chute  16  is continuously moved between first-intermediate-second positions until a predetermined number of containers has been filled or the material flow is exhausted. 
     Another example will now be described with reference to pneumatic circuit  48  shown in FIG.  9  and the weighing and bagging devices  26 ,  28  shown in FIG.  10 . FIG. 9 shows a pivotable link  40  which is attached to the shaft  22  such that movement of end  42  of link  40  causes the link  40  to pivot about axis  24  and thereby pivot the chute  16  between the first-intermediate-second positions. The weighing and bagging devices  26  and  28  each includes an air switch (not shown) to sense whether or not a container  12 ,  14  has been mounted in respect thereto. The circuit  48  also includes flow control valves  44  and  46 , air cylinders  50 ,  52 ,  54  and  56  and control valves  58 ,  60 ,  62 ,  64 ,  66  and  68  which are all controlled by a Programmable Logic Controller (PLC) (not shown). 
     While air cylinders  50 ,  52 ,  54  and  56  will cause link  40  to pivot about axis  24  in order to pivot chute  16  to a first or second position or an intermediate position, adjustment mechanisms  108  and  110  (refer also FIG. 11) can provide fine adjustment of the flow from chute  16  into container  12  or  14 . For example, rotation of wheel  112  or  114  will enable arm  116  or  118  respectively to make small adjustments in movement of end  42  of link  40 , thus making fine adjustments in the position of chute  16 . In this way, in some embodiments of the invention, it is possible to direct a very small proportion, say 10 grams, of the flow from chute  16  into container  12  and the rest of the flow into container  14 . 
     FIG. 10 shows one of the weighing and bagging devices  26 ,  28 , each of which includes a filling head  41  to which one of the container  12 ,  14  respectively, such as a bag, may be clamped. A flexible shroud  43  ensures material leaving the fixed guides  30 ,  32  does not spill whilst entering the filling head  41 . Each of the filling heads  41  extends horizontally at right angles from a beam  45  which is mounted to the chassis of the apparatus  10  by two load cells  47 A,  47 B. The signals generated by each pair of the load cells  47 A,  47 B are calibrated to indicate the weight in each of the container  12 ,  14  in one of the respective pair of displays  49 . 
     The circuit  48  receives control signals from the PLC in response to signals issued by the displays  49  through lines  51  indicating their respective container are, for example, 70%, 85%, or 100% of the total predetermined desired “full” container weight (known as set points one, two and three respectively). The displays  49  can be manually reset to provide other weight set-points. 
     As seen in FIGS. 10 and 11, when the apparatus  10  is activated, power is supplied to the weighing units  26  and  28  and the cylinders,  50  end  52  are retracted. The PLC then checks the state of the associated air valve to sense if a container  12  is clamped to the weighing device  26 . If the container  12  is sensed to be present, the PLC energises the mechanism supplying the outlet  15  with flowable material, for example, an auger driven by a variable speed electric motor, and drives the motor at a speed inducing material flow at its highest possible rate. The chute  16  is in the first end position of FIG.  2  and directs all of the material flow into the first container  12 . If the container  12  is not sensed to be present, the motor is not energised. 
     At set point one, the PLC checks to see if the other air valve is indicating whether the second container  14  is present at the second weighing and bagging device  28 . If the container  14  is not present, the material flow is stopped. If the container  14  is sensed to be attached to the second weighing and bagging device  28 , then the first set point is ignored, and flow continues into the first container  12 . 
     At set point two, the PLC slows the motor to a speed inducing medium material flow and the cylinder  52  is extended to pivot the chute  16  to an intermediate position above the edge  34  so as to direct 10% of the material flow into the first container  12  and the remaining 90% of the material flow into the second container  14 . At set point three, cylinders  54  and  56  are retracted so that the chute  16  is pivoted to the second end position directing all of the material flow into the second container  14 . After a predetermined elapsed time to allow for the fall of inflight material, the PLC releases the container  12  from the (left hand side) filling head  41  so another empty container  12  can be attached for filling. The above process is then repeated in relation to the second container  14  and so on. 
     The flow control valves  44  and  46  connected to the cylinders  52  and  54  respectively ensure the chute  16  pivots relatively smoothly and slowly from an end to an intermediate position. The cylinders  50  and  56  do not use such a valve so they pivot the chute from an intermediate position to an end position as quickly as possible. 
     As an example in relation to filling a 20 kilogram bag, the first set point may be set at approximately 16 kilograms, the second set point approximately 19 kilograms and the third set point 19.95 kilograms (to allow for 0.05 kg of inflight material). 
     The apparatus  100  in FIG. 11 includes a vibrating tray  102  gravity fed directly from a hopper  104  to supply flowable material to the first and second fixed guides  30  and  32 . The position of the outlet edge  106  of the tray  102  over the edge  34  of the guides determines the division of the material flow. Adjustment mechanisms  108  and  110  allows the tray position in each of the two intermediate positions to be varied to a fine degree, as discussed above. 
     In the example described above, there were three set points. As an example of a further variation, the first set point may be eliminated. As a safety precaution, at the set point indicating that a container is 85% full, the PLC can be programmed to check whether the other container is in place before pivoting chute  16  to an intermediate position as described above. 
     FIG. 12 a  shows the tray  102  in the first position directing all the material flow to the first container. FIG. 12 b  shows the tray  102  in the first intermediate position directing the majority of the flow to the second container. FIG. 12 c  shows the tray  102  pivoting to the second position. FIG. 12 d  shows the tray  102  directing all the flow to the second container. FIG. 12 e  shows the tray  102  in the second intermediate position directing the majority of the flow to the first container. FIG. 12 f  shows the tray  102  back in the first position. 
     FIG. 13 shows a further embodiment of a filling apparatus  120  having a substantially vertical nozzle  122  connected to a hopper  124  by a flexible tube  126 . A gate valve  128  controls flow from the hopper  124  to the tube  126 . The cylinders  50 ,  52 ,  54  and  56  are connected to the nozzle  122  by yoke  130  and pivot the nozzle  122  in a substantially vertical plane to adjust its position relative to the edge  34  between the first and second guides  30  and  32  respectively. 
     FIGS. 14 and 15 show yet a further embodiment of a filling apparatus  150  having a substantially horizontal nozzle  152  fed by an auger  154 . The auger  154  is pivoted in a substantially horizontal plane to vary its position relative to the edge  34  of the guides  30  and  32 . 
     Referring to FIGS. 16 to  19 , there is shown an embodiment of an apparatus  101  for filling a plurality of containers including a first container  102 , a second container  103 , a third container at  104  and a fourth container at  105 , with flowable material. The containers are positioned at filling stations  120 , which are in a line. The flowable material  106  leaves the material feed  107  from, for example, an overhead hopper (not shown). The containers, once filled, may be replaced with empty containers for filling. 
     Each of the containers  102  and  103  is releasably mounted to respective weighing and bagging devices  108 . Above each of the weighing and bagging devices  108  there is a material guide  109  having inclined walls  110  and  111 . An edge  112  forms the apex of two inner inclined walls  110  and  111 . The material feed  107  and the material guide  109  are desirably manufactured from stainless steel for ease of cleaning and corrosion resistance. 
     The material guide  109  is adapted to move along the line of filling stations, from container  102  to container  105 , so that each container is filled sequentially. First, all of the material input from the hopper is directed into the first container  102 , as shown in FIG.  17 . At the intermediate positions, the flowable material  106  is incident on the edge  112  and thus divided between the first and second containers  102  and  103  respectively, as shown in FIGS. 16 and 18, with about 10% of the flow directed into container  102  and the balance directed into container  103 . Material feed  107  remains stationary and filling stations (with their associated containers) are conveyed to the left as shown in FIGS. 17 to  19 . 
     As edge  112  passes under material feed  107 , the greater proportion of the total available material flow is directed to one of the adjacent containers and a lesser proportion of the total available material flows to the other adjacent container. This allows a very slow flow rate of material to be directed into a container which is nearly full for accurate final filling and weighing off whilst the larger remaining flow of material can be simultaneously filling another container, thereby increasing accuracy and reducing overall filling times. 
     As an example, the apparatus  101  can be configured such that the material guide  109  will initially direct all of the material flow to the first container  102  until the weighing and bagging device  108  indicates that the container  102  is approximately 85% full. At this point, the material feed  107  is in a position above the edge  112  where 10% of the overall material flow  106  continues to fill the first container  102  and the remaining 90% of the flow commences to fill the second container  103 . When the first container  102  is 100% full, the filling stations have moved to the position where material feed  107  directs all of the material flow  106  to the second container  103 . As the second container  103  reaches 85% full, 10% of the flow is directed to the second container  103  and the remaining 90% to the empty third container  104 . This process is repeated until the third container  104  is 85% full. The remaining portion of the third container  104  is filled with 10% of the flow and filling of the fourth container  105  with 85% of the flow commences. The process is continued until a predetermined number of containers has been filled or the material flow is exhausted. Filled containers can be replaced with empty ones, and the direction of movement of the filling stations reversed. 
     FIG. 20 shows another preferred embodiment. The apparatus  201  is arranged in a generally wheel formation such that when flowable material  206  flows from material feed  207  (which is shown as a chute as an example only) the filling stations  220  rotate relative to the material feed  207  in a clockwise direction as shown by arrow  214 . As filling stations  220  move relative to material feed  207 , flowable material  206  flows over edge  212 . In doing so, flowable material  206  flows into a first container (not shown), and a second container (not shown). As the first container becomes completely filled, the second container and a third container (not shown) start to have material flow into them. The first container may be removed (the containers being removably attached to weighing and bagging device  208 ) and replaced with an empty container so that, when the wheel has rotated through 360 degrees the empty container will start to be filled. Empty containers  213  are shown as representative of the first, second and third containers concealed behind the wheel mechanism. 
     The direction of motion shown by arrow  214  may easily be reversed. The weighing and bagging devices  208  are attached to the wheel mechanism by a support strut  215 . In this way of replacing the containers as they become filled, a continuous process of container filling occurs until either the flow of material is exhausted or sufficient numbers of containers have been filled. 
     INDUSTRIAL APPLICABILITY 
     A significant advantage of the filling apparatus is that the material flow need not be stopped. Once a first container is filled to a set point, a second container can be begun to be filled while the final portion of material fills the first container. If the filling stations are arranged in a loop with removably attached weighing and bagging apparatus, the containers can be accurately filled until the flow of material is stopped or the flow of material is exhausted by replacing the containers as they become filled. 
     Another advantage is the effect on filling and weighing accuracy. Inaccuracies due to any change of flow rate, through surging or pulsing of the material flow, are greatly reduced because, during the final weighing off, only 10% of the actual maximum flow of the material need be involved. 
     A related advantage is that the overall filling rate is no longer limited to a rate giving acceptable weighing off accuracy. In the examples given, the filling flow rate for most of the container may be nine times the weighing off flow rate. Further, the reduced rate of feed from the chute or the like in the intermediate position can be easily adjusted to give a desired degree of accuracy in relation to the type of product being weighed and filled. 
     Also, the load cells of the weighing and bagging devices (if used) can be linked to visual displays so that the actual weight of the containers may be continually displayed to operators and through appropriate software can be linked to printers, data recorders or the like. 
     Another advantage, especially in relation to the food industry, is that the internal components of the apparatus are simple and easy to clean and maintain. 
     Although the invention has been described with reference to certain preferred embodiments, it will be appreciated by those skilled in the are that the invention is not limited thereto.