Abstract:
A method of filling containers, especially bags, with bulk material by a feeding funnel and a filler pipe. The filler pipe adjoins the lower end of the feeding funnel. An axially displaceable and rotatable conveying unit is arranged co-axially within the filler pipe. An axially displaceable and rotatable closing element is firmly connected to the lower end of the conveying unit. The bulk material, while being conveyed by the conveying unit in the filler pipe, is simultaneously mechanically agitated in the filling funnel, or simultaneously mechanically conveyed in the filling funnel towards the filler pipe.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a method of filling containers, especially bags, with bulk material by a feeding funnel and a filler pipe. The filler pipe adjoins the lower end of the feeding funnel. The filler pipe includes an axially displaceable and rotatable conveying unit arranged co-axially in the filler pipe. Also, an axially displaceable and rotatable closing element is positioned at the lower end of the filler pipe. The closing element is firmly connected to the lower end of the conveying unit. Furthermore, the invention relates to a device for filling containers, especially bags, with bulk material. The device includes a feeding funnel and a filler pipe. The filler pipe adjoins the lower end of the feeding funnel. The filler pipe includes an axially displaceable and rotatable conveying unit arranged co-axially in the filler pipe. Also, an axially displaceable and rotatable closing element is positioned at the lower end of the filler pipe. The closing element is firmly connected to the lower end of the conveying unit.  
         BACKGROUND OF THE INVENTION  
         [0002]    A method and device are known from DE 199 62 475 A1. Here a worm-or-spiral-shaped conveying unit, at its lower end, is firmly connected to a closing cone. Accordingly, a joint rotary drive and a joint lifting drive can be used for the conveying unit and the closing element. In a preferred embodiment, it is possible to continuously adjust the lifting height of the closing element and to rotatingly drive the closing element when the closing element is open. This achieves particularly advantageous dispensing results while avoiding the risk of the formation of bridges in the exit gap between the filler pipe and the closing element. If the bulk material is sticky it constitutes a problem. When conveying sticky material, it is possible, in spite of the forced conveyance taking place from the filler pipe to the exit gap, for the sticky material to continue to form bridges in, and adhere to the wall of the feeding funnel. The bridges and adhesion fundamentally and adversely affect the dispensing function of the device. In addition, even if the device still dispenses accurately, problems still exist. One such problem is bulk material adhering to the wall of the feeding funnel. It is possible, at a later stage, for the aged, sticking or baked bulk material to break loose from the feeding funnel. This breaking off is totally unacceptable in view of the required quality of the bulk material, or in the case of food, for hygienic reasons. The wedge shape of the feeding funnel favors the occurrence of such defects.  
           [0003]    DE 198 28 559 C1 illustrates a dispensing device of a similar type. Here the assembly includes a conical feeding tunnel and an adjoining filler pipe. A spiral-shaped, rotatingly drivable conveying unit is positioned in the filler pipe. An independently rotatingly drivable and axially displaceable closing element is arranged. The conveying unit extends upwardly into the feeding funnel. The conveying unit carries a bar-shaped stirring mechanism at its upper end in the feeding funnel. The closing element can be withdrawn into the filler pipe towards the conveying spiral ending at a higher level to open an annual exit gap. This can result in a compaction of the flow of filled-in bulk material and to dispensing interference.  
         SUMMARY OF THE INVENTION  
         [0004]    It is an object of the present invention to provide a method and device that dispenses problematic bulk material. Accordingly, sticky bulk material with a tendency to form bridges can be dispensed in constant quantities and in a constant material quality. A first solution provides a method where the bulk material, while being conveyed by the conveying unit in the filler pipe, is simultaneously mechanically agitated by an agitating means in the feeding funnel. This solution provides a device including a feeding funnel with a conical shape and agitating elements close to the wall of the feeding funnel. The agitating elements are rotatably drivable around the funnel axis. In a second solution, the bulk material, while being conveyed by the conveying unit in the filler pipe, is simultaneously mechanically conveyed by conveying means in the feeding funnel feeding bulk material towards the filler pipe. This solution provides a device including a conical shape feeding funnel. Conveying elements are rotatably drivable around the funnel axis in the feeding funnel.  
           [0005]    These two solutions can be used on their own or in combination with one another. According to the first solution, the bulk material is agitated in the feeding funnel. The agitating elements are close to the funnel wall preventing any bulk material from adhering to the wall. This ensures a constant flow of material to the filler pipe. The agitating elements are in the form of leaves extending parallel to the wall of the feeding funnel. The leaves are preferably arranged to extend axially non-displaceable relative to the funnel axis. The leaves are at a constant distance from the funnel wall. The constant distance of the leaves from the wall of the feeding funnel ensures that the agitating process is continuously effective. Agitation in the feeding funnel takes place at a lower rotation frequency than the driving of the conveying unit for the purpose of conveying the bulk material in the filler pipe. The agitating elements in the feeding funnel and the conveying unit in the filler pipe can be driven, via suitable transmission ratios, by a common drive unit. Also it is possible to provide separate drive units. Thus, continuous agitation in the feeding funnel is possible even in cases where the rotatingly drivable conveying unit is not driven and when the closing element is in the closed position.  
           [0006]    According to a second solution, inside the feeding funnel, especially in a central region, the bulk material is additionally conveyed towards the filler pipe. If there is only a risk of forming bridges of powdery materials and if the stickiness of the material is less of a concern, the second solution ensures a reliable flow of material from the feeding funnel into the filler pipe. Accordingly, the conveying means in the filling funnel is driven at the same rotation frequency as the conveying unit in the filler pipe conveying the bulk material. In this connection, the conveying elements in the feeding funnel are arranged at a constant axial distance from the conveying unit in the filler pipe. Thus the lifting and lowering of the conveying unit cannot result in internal compaction processes. It is particularly advantageous to use the same drive unit. The drive unit can also act on a single common drive shaft. The drive shaft is firmly connected to both the conveying unit in the filler pipe, with an attached closing element, and to the additional conveying elements in the feeding funnel. The shaft is axially adjustable together with the driving motor or relative to the driving motor.  
           [0007]    According to a second variant, the conveying elements in the feeding funnel are axially firmly positioned in the feeding funnel, especially in the upper funnel region. Thus, the distance from the axially displaceable conveying unit changes when opening and closing the closing element. This embodiment enables a common drive unit, but it has to drive two shafts which are arranged one inside the other. The shafts are axially displaceable relative to one another. The shafts are provided for the conveying elements in the feeding funnel and for the conveying unit in the filler pipe. The additional conveying elements may have the shape of a worm portion, of individual blades or of a spiral portion. The conveying elements comprise a gradient relative to the axis of the feeding funnel.  
           [0008]    On the upper face of the closing element, which is rotatingly drivable together with the conveying unit, it is possible to arrange blades with or without a gradient relative to the longitudinal axis. The blades improve the dispensing flow. The rotational and axial movement of the conveying unit and closing element can, as is already known, be controlled independently of one another or depend on one another in accordance with certain functions. The closing cone at the lower end of the conveying unit is preferably removably attached. However, in the fully assembled condition, the two parts form a structural unit. In this way, pockets of dirt and dead spaces in the material flow can already largely be avoided by design measures. The conveying unit is preferably an endless worm on a central shaft. In a preferred embodiment, the closing cone has the same cross-section as the shaft where it directly joins the shaft. In its lowest region with the greatest diameter, the closing cone includes a sealing portion. When the closing cone is in the lifted position, the sealing portion sealingly rests against the lower end of the filler pipe.  
           [0009]    Additional objects and advantages of the present invention will become apparent from the detailed description of the preferred embodiment, and the appended claims and accompanying drawings, or may be learned by practice of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is an axial section view of the complete device in an open position with the closing element wide open.  
         [0011]    [0011]FIG. 2 is an axial section view of the supporting and driving means of the conveying unit and the agitating device according to FIG. 1.  
         [0012]    [0012]FIG. 3 is a cross-section view of the supporting and driving means according to FIG. 2 positioned perpendicularly relative to FIG. 2.  
         [0013]    [0013]FIG. 4 is a horizontal section view of the supporting and driving means according to FIG. 3.  
         [0014]    [0014]FIG. 5 is an enlarged section view of the closing element through the filler pipe in an open position.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    [0015]FIG. 1 illustrates a device of the invention with a conical feeding funnel  11  with a filler sleeve  12  adjoining the top end of the feeding funnel  11 . The filler sleeve  12  is axially offset. A filler pipe  13  co-axially adjoins the lower end of the feeding funnel  11 . A conveying worm  14  is arranged in the filler pipe. The conveying worm  14  is carried by a worm shaft  15 . A closing cone  16  is arranged at the lower end of the worm shaft  15 . The closing cone  16  widens towards its lower end.  
         [0016]    The feeding funnel  11  is covered by a base plate  10  for the supporting and driving means. The supporting and driving means are carried by a frame  18 . The shaft is supported twice in a way described hereinafter. The shaft is driven by a cog belt  20  coupled to a driving motor  17  which is bolted to the frame  18 .  
         [0017]    A first belt pulley  21  is arranged on the shaft journal of the driving motor  17 . A second belt pulley  22  is arranged on a driving sleeve  19 . The worm shaft  15  is rotationally secured and axially displaceable on the sleeve  19 . The driving sleeve  19  can be a torque ball bush whose balls engage ball grooves. The upper end of the worm shaft  15  is suspended by an axial bearing  23  in a portal carrier  26 . In FIG. 1 the bearing  23  and carrier  26  are shown jointly in two different axial positions.  
         [0018]    A setting motor  28  adjusts the portal carrier  26 . The setting motor  28  is also bolted to the frame  18 . The setting motor  28  acts on a cog belt  29 . A first belt pulley  27  can be seen on the shaft journal of the setting motor  28 . The worm shaft  15  is supported underneath the driving sleeve  19  by an upper radial bearing  30  on the frame  18 . The worm shaft  15  is supported at the level of the funnel opening of the feeding funnel  11  by a lower bearing assembly  31 ,  32 .  
         [0019]    An agitating device  33  is positioned in the feeding funnel  11 . The agitating device  33  is suspended at a sleeve  34  which is rotatable independently of the worm shaft  15 . The sleeve  34  is supported directly in the frame  18 . The agitating device  33  has a radial arms  35  starting from the sleeve  34 . Leaf elements  36  are stiffened by bars  37 . A chain wheel  38  is at the upper end of the sleeve  34 . The chain wheel  38  enables the agitating device  33  to be independently rotationally driven.  
         [0020]    A conveying element is positioned in the lower central region of the feeding funnel. The conveying element is in the form of a worm turn  41  positioned on the worm shaft  15 . Underneath the worm turn  41 , a union nut  42  connects the two parts of the worm shaft  15 . Blades  43  are provided at the closing cone  16 . The entire assembly can be suspended above a net weighing device by frame  50 .  
         [0021]    [0021]FIGS. 2 and 3 will be described jointly below. Identical details have been given the same reference numbers as in FIG. 1. To that extent, reference is additionally made to the description of FIG. 1.  
         [0022]    [0022]FIG. 2 compared to FIG. 1, contains additional sectional views showing the upper axial bearing  23  supporting the upper shaft end in the portal carrier  26 ; the radial bearing  30  supporting the driving sleeve  19  on the frame  18 ; the lower bearing assembly with an outer radial bearing  31  supporting the sleeve  34  in the frame  18 ; and an inner radial bearing  32  supporting the worm shaft  15  in the sleeve  34 .  
         [0023]    A rotational and axial guiding sleeve  45  is slipped on to the worm shaft  15 . The sleeve  45  is a ball bush providing rotational and axial guidance by the balls running on the shaft shank. The shaft is sealed towards the outside by a protective tube  46  between the driving sleeve  19  and the rotational and axial guiding sleeve  45 . The rotational and axial guiding sleeve  45 , at its lower end, is followed by a sleeve  47 . The sleeve  47  carries a flexible sealing sleeve  48  sealingly resting against the worm shaft  15 .  
         [0024]    [0024]FIG. 3 shows a further driving motor  51  connected to an supporting iron angle  52 . The iron angle  52  is firmly connected to the base plate  10 . A chain wheel  53  is positioned on the shaft journal of the driving motor  51 . The chain wheel  53 , via a chain  54 , establishes a driving connection with the chain wheel  38  of the agitating device  33 . The portal  26  is a U-structure which opens downwardly. The axial bearing  23  is positioned in the upper transverse carrier. The two arm ends of the portal  26  are connected to spindle nuts  24 . The spindle nuts  24  run on spindles  25  which are doubly supported in the frame  18 . Upper bearings  55  and lower bearings  56  support the spindles  25 . Belt pulleys  57 , drivable via the cog belt  29  by the belt pulley  27  of the setting motor  28 , are arranged on the spindle journals projecting from the lower bearings. The spindles  25  are rotatingly driven by actuating the setting motor  28 . Thus, the spindle nuts  24  together with the portal  26  are lifted and lowered. The portal  26 , in turn, lifts and lowers the worm shaft  15 , via the axial bearing  23 . The spindles  25  are sealed by upper bellows  58  and lower bellows  59 . Air equalizing lines  60  are provided to equalize the pressure between the bellows  58 ,  59 .  
         [0025]    Conveying blades  39  are attached to the shaft sleeve  34 . The conveying blades  39  extend at a gradient relative to the axis. Angle plates  40  attach the conveying blades  39  to the agitating device  33 . Leaves  36  extend parallel to the wall of the feeding funnel  11 . The conveying blades  39  are not axially displaceable in the feeding funnel. Due to the conveying blades  39  small circumferential extension, low rotation frequency and long distance from the conveying worm  14  and shaft  15  in the filler pipe  13 , there is no risk of material compaction. The conveying blades may be replaceable or adjustable with respect of the gradient in order to adapt the conveying blades  39  to the product characteristics.  
         [0026]    In FIG. 4, any details identical to those shown in the previous Figures have been given the same reference numbers. To that extent, and in addition, reference is made to the description of the previous Figures. FIG. 4 shows the base plate  10  of the feeding funnel  11  and the filler sleeve  12 . The setting motor  28  attached to the frame  18  is secured to the base plate  10 . The belt pulley  27 , via cog belt  29  is coupled with the belt pulleys  57  of spindles  25 . The driving motor  51  via the supporting angle  52  is secured to the base plate  10 . The driving motor, via the chain wheel  53 , the chain  54  and the chain wheel  38  on sleeve  34 , drives the agitating device  33 .  
         [0027]    [0027]FIG. 5 shows the lower end of the filler pipe  13  with the worm shaft  15  and the conveying worm  14 . A valve seat  61  is attached to the end of the filler pipe  13 . The worm shaft  15  is followed by the closing cone  16 . The upper side of the closing cone  16  includes the above-mentioned blades  43 . The lower part of the cone  16  is formed by two plastic discs  62 ,  63  sandwiching an inserted seal  64 . These parts are connected to the cone  16  by holding means  65 , not described in greater detail.  
         [0028]    While the above detailed description describes the preferred embodiment of the present invention, the invention is susceptible to modification, variation and alteration without deviating from the scope and fair meaning of the subjoined claims.