Abstract:
Automated apparatus for filling of a bag with a loose commodity comprises a bag filling station for dispensing commodity into a bag; a wicket for feeding a stacked and interconnected array of empty bags; and a conveyor for removing filled bags from the filling station. Reciprocating clamps grip the open mouths of the filled bags, and transfer the filled bags away from the filling station, with a subsequent bag being drawn into appropriate position for filling by means of the connection formed between the contacting bags.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to packaging technology, and in particular to an apparatus and method for filing bags with a loose commodity such as seed or grain, by means of an automated apparatus, and carrying the filled bags to a bag sealing station or other processing means.  
         BACKGROUND OF THE INVENTION  
         [0002]    The bagging of bulk commodities such as seed or grain requires automated equipment for sequentially dispensing a measured quantity or weight of a commodity into an open-topped bag, and transferring the bag to a heat sealing station or other bag-sealing means. Typically in apparatus of this nature, the bulk commodity is dispensed from a hopper into an open-topped bag. After a measured amount is dispensed, the bag is removed from the hopper and discharged from the apparatus. Typically, individual bags are positioned beneath the hopper sequentially. Modem commodity-handling operations require bag filling machines that are-capable of operating rapidly and effectively, that is, with a minimum of skipped bags (wherein a bag is missing when the hopper discharges it s load), torn or damaged bags, or doubled-up bags.  
           [0003]    Typically, rapidity and precision are achieved by means of an automated device having moveable fingers or other gripping members for manipulation of individual bags before, during and after the filling operation. For example, published Canadian Application 2,091,471 (Huwelmann) discloses a bag-filling apparatus having opposed clamping mechanisms for gripping the open upper end of the bag, and holding the bag open for filling by a hopper or the like. Similarly, U.S. Pat. No. 4,172,349 (Lipes) discloses opening of a bag by means of a pair of opposed gripping members that grip opposing sides of the bag and hold it open at its mouth. A similar arrangement is disclosed in U.S. 4,651,506 (Lerner et al.).  
           [0004]    One requirement is that such apparatus accurately and rapidly transfer individual bags from a bag supply to a filling station and subsequently to a conveyor for transferring the bag to a heat-sealing mechanism or other bag-handling subsystem. This sequence may be efficiently carried out if the bags are transferred efficiently between the various stations.  
           [0005]    A further specific requirement that is not adequately addressed in the prior art is for a simple, effective and rapid means whereby empty bags are individually engaged and positioned in an open-topped position to receive a bulk commodity from a hopper or other filling means.  
           [0006]    In general terms, it is desirable to provide a mechanism whereby empty bags may be sequentially engaged and transferred in an open position to a bag-filling station, and subsequently transferred to a bag conveyor. Conveniently, the individual bags may be drawn closed as they are being fed to the downstream conveyor. Since typically the downstream conveyor feeds the bags into a heat-sealing station comprising a pair of heated rollers or belts, it is desirable that the mechanism draws the sides of the bags together to form a flattened upper region of the bag to receive a heat seal.  
         OBJECTS OF THE INVENTION  
         [0007]    In light of the foregoing, it is an object of the present invention to provide an improved bag filling apparatus and method, whereby individual bags are selectively engaged and positioned for individual filling and subsequently are withdrawn from the filling station in a generally lateral direction for transfer to a downstream conveyor. It is a further object to provide a means whereby the filled bags are generally substantially closed at their upper ends as the bags are transferred to the downstream conveyor, in such a manner as to permit the bags to be conveniently heat sealed at their upper ends.  
         SUMMARY OF THE INVENTION  
         [0008]    In accordance with the foregoing objects, the invention comprises in one aspect an apparatus for filling bags with a loose commodity and transferring filled bags to a processing means, comprising:  
           [0009]    a bag filling station for dispensing a measured quantity of the commodity into bags;  
           [0010]    a wicket for receiving empty bags in a stacked and interconnected array whereby the bags form a continuous web; and  
           [0011]    filled bag transfer means incorporating a releasable clamp for engaging an open mouth of a bag upon filling the bag with the commodity and withdrawing the filled bag away from the hopper.  
           [0012]    The interconnection of the bags may be achieved by a mechanical interconnection, for example interlocking edge regions of adjacent bags, or surface effects such as surface tension or electrical attraction between contacting bags.  
           [0013]    The releasable clamp draws the open mouth of the bag into a taut position upon engaging the bag. The direction of transfer of the filled bags permits removal of a filled bag from the filling station to draw a subsequent empty bag from said wicket to the filling station and detach the full bag from the subsequent bag. The transfer means then transfers the filled bags from the filling station to the processing means.  
           [0014]    Preferably, the transfer means sequentially transfers the bag in a first direction generally perpendicular to the elongate axis of the apparatus for detaching a filled bag from a subsequent bag, and subsequently in a second direction generally parallel to the elongate axis for delivering filled bags to the processing means.  
           [0015]    The clamp of the preferred version comprises a pair of laterally moveable fingers associated with drive means for moving the fingers between converged and diverged positions. The reciprocating fingers engage opposed corresponding fixed fingers, whereby opposed ends of the bag are clamped between respective pairs of moveable and fixed fingers when the moveable fingers are diverged, and the bag is released from the clamp member when the moveable fingers are converged. The position of the fixed fingers may be laterally adjusted to converge or diverge to accommodate a selected size of bag.  
           [0016]    The filling station preferable includes a hopper having a downwardly-depending nozzle for discharge of the loose commodity, and further comprising reciprocating drive means for elevating the hopper during the bag removal stage and lowering the hopper during the bag filling stage.  
           [0017]    An intermediary conveyor means may receive the filled bags from the transfer mean, to convey the bags by their upper rim to a heat sealing station or the like. The intermediary conveyor may comprise a pair of opposing elongated conveyor members, such as a pair of endless belts driven by pulleys, that diverge to receive a bag and converge to engage and transport the bag.  
           [0018]    In a further aspect, the invention comprises a method for filling a bag with a loose commodity and transferring the filled bags to a processing means, comprising the steps of:  
           [0019]    providing a bag-filling apparatus featuring a bag filling station, a wicket, and filled bag transfer means;  
           [0020]    loading a supply of empty bags on the wicket in a stacked and interconnected array to form a continuous web;  
           [0021]    opening the mouth of a first bag on the wicket;  
           [0022]    filling the first empty bag with loose commodity at the filling station;  
           [0023]    transferring the filled bag, away from the filling station towards the processing means thereby drawing a second connected bag into said filling station, opening the mouth of the empty bag and detaching said first bag from said second bag; and transferring the filled bag to the processing means.  
           [0024]    The step of transferring the filled bag away from the filling station may comprise transferring the filled bag in a first direction for detaching the filled bag from the subsequent bag, and subsequently in a second direction towards the processing means. Alternatively, transfers within the first and second directions may occur essentially simultaneously.  
           [0025]    The step of transferring the filled bag may include the step of drawing the open mouth of the bag to a substantially closed configuration, by drawing apart opposed ends of the upper region of the bag, thereby drawing together the opposed sides of the bag, and delivering the substantially closed bag to the processing means.  
           [0026]    Having thus described the invention in general terms, the invention will now be further characterized by reference to a description and illustrations of a preferred embodiment.  
           [0027]    The directional references employed throughout this specification are in relation to the longitudinal axis of the machine comprising the direction the general direction of movement of the bags subsequent to the filling stage, i.e., from the filling station to the heat sealing station or other downstream processing means. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]    [0028]FIG. 1 is a plan view, from above, showing-the apparatus according to the present invention;  
         [0029]    [0029]FIG. 2 is a perspective: view of the apparatus, illustrating the: conveyer within the closed position;  
         [0030]    [0030]FIG. 3 is a further perspective view, illustrating the conveyer within an open position;  
         [0031]    [0031]FIG. 4 is a further perspective view of the apparatus;  
         [0032]    [0032]FIG. 5 is a further perspective view of the apparatus;  
         [0033]    [0033]FIG. 6 is a side elevational view of a portion of the apparatus;  
         [0034]    [0034]FIGS. 7 a  through  i  comprise a series of perspective views, of a portion of the apparatus, illustrating operation of the apparatus;  
         [0035]    [0035]FIG. 8 is a perspective view of a portion of the device, illustrating a further embodiment of one aspect thereof;  
         [0036]    [0036]FIG. 9 is a further perspective view as in FIG. 8;  
         [0037]    [0037]FIG. 10 is a side elevational view of the portion shown in FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]    Referring to the figures, the apparatus globally denoted by reference  10  is supported on a frame  16 . The apparatus comprises a bag-filling station  20 , having associated therewith a bag wicket station  22  and a bag transfer station  26 . The bag-filling station comprises a vertically reciprocating hopper  28 , which is driven for a reciprocal vertical movement by a pneumatic drive cylinder  30 . A supply conduit  32  feeds grain or other loose, bulk commodity (not shown) into the hopper  28 . Release of commodity from the hopper  28  is controlled by means of an openable jaw structure  34  which defines the lower portion of the hopper and comprises a fixed jaw member  36 ′ and a moveable jaw member  38  which pivots about a horizontal axis. The moveable jaw member  38  is driven for a reciprocal movement diverging and convergin with the fixed jaw member  36  by a pneumatic cylinder  40  mounted to the hopper  28 . In the closed position, shown in FIG. 2, the respective jaw structure  34  closed and commodity cannot escape from the hopper  28 . Within the-open position, shown in FIG. 7( c ), the jaw structure  34  is opened for the discharge of a measured amount of commodity from the hopper  28 .  
         [0039]    The bag wicket station  22  comprises a generally box-like support structure  43  mounted to the frame  16 , and which slidably engages the hopper  28 . The pneumatic cylinder  30  driving the hopper is mounted to an upper portion of the support structure  43 . The wicket station  22  features a pair of wicket members  44 , from which may be hung a flattened stack of empty bags  46  for filling with the commodity. The wicket members are angled downwardly to urge the bags towards the filling station via gravity. A pair of holes  48  extend through the upper rim portion of the bags  46  adjacent opposed sides thereof, to engage the wicket members  44 . The bags  46  are interconnected to form an endless web or chain.  
         [0040]    In a further aspect, an alternative arrangement of the wicket station is shown in FIGS. 8 through 10. Within this version, a wicket station  200  comprises paired wicket arms  202 , which are angled downwardly towards the feeding station to feed the bags  46  via gravity towards the feeding station. The wicket arms  202  terminate at a plate like wicket knife assembly  206 , mounted to the wicket station  22 . A wicket knife  208  forms a gusset like web between the plate  206  and the wicket arms  202 . The wicket knife has a knife edge  210  for slicing the bags as the same are drawn forwardly for removal from the wicket. Use of the wicket knife assembly, and consequent cutting of the bag, permits easier removal of the bags from the wicket with less stretching than a simple tearing action against the rounded wicket arms. FIG. 9 illustrates with arrow  212  the direction of tearing of the bag as the same is pulled forwardly off the wicket, with the tear origin occurring at point  214  on the bag.  
         [0041]    Conveniently, the interconnection may result from surface tension, static or electrical forces between the bags or mechanical forces achieved by deformation of a portion of the bags surrounding the holes, which permits each bag to lightly grip its neighbours. The interconnection between the bags is sufficient to permit each bag to draw it&#39;s neighbour forwardly and open the mouth of the neighbouring bag, as each bag is removed from the wicket upon filling. The term “interconnection” encompasses a physical connection formed by eg. deformation of adjacent bags forming an interlocking structure, or surface effects such as surface tension forming a connection between adjacent bags.  
         [0042]    The bag transfer station  26  comprises in general terms a bag gripper assembly  50 ; a gripper carriage assembly  52 ; and a bag conveyer station  54 . The gripper assembly  50  is adapted to grip individual bags  46  and position each bag sequentially beneath the hopper  28  for filling with the commodity. Upon filling of the bag  46 , the gripper assembly  50  and its associated carriage assembly  52  carry the bag to the conveyer station  54  which in turn receives the filled bag for conveyance to a heat sealing station  56  or other downstream processing means.  
         [0043]    The gripper assembly  50  comprises a generally plate-like vertical base  60 . A pair of fixed arms  62 ( a ) and ( b ) extend laterally from either end of the base  60  towards the hopper  26 . Each of the outer arms  62  terminates in a downwardly-extending finger  64 . The fingers  64  are a dustable on the arms  62  to accommodate bags of differing sizes requiring a greater or lesser spread of the fingers  64  to hold the bags generally taut. Positioned between the fixed outer arms  62  and parallel thereto is a pair of moveable inner arms  66 ( a ) and ( b ), having a similar configuration and each terminating in a downwardly depending finger  67 . The inner arms  66  are each mounted to the base  60  for slideable movement relative to the base  60 . The inner arms  66  are each connected to a corresponding pneumatic cylinder  70  mounted to the base  60 , with the cylinders adapted to drive the inner arms  66  between reciprocating converging and diverging positions. The inner arms  66  are reciprocate between a converged first position, shown in FIG. 7( a ), wherein the fingers  67  of the inner arms  66  are spaced substantially apart from the fingers  64  of the fixed outer arms  62 , and a second diverged position; shown in FIG. 7( b ), wherein the respective fingers  64  and  67  of the inner and outer arms meet to clampingly engage a bag  46  therebetween.  
         [0044]    It will be understood that the linear reciprocating motion of the cylinders  70 , as well as all other like drive means, may be replaced by any suitable drive means including rotary drive means such as a revolving wheel, with the driven member being pivotally mounted at a position adjacent the wheel perimeter for reciprocating sinusoidal movement.  
         [0045]    The carriage assembly  52  is adapted to carry the gripper assembly  50  in three axis of movement, namely laterally, longitudinally and vertically. The carriage assembly  52  comprises a carriage frame  80 , mounted to the apparatus frame  16 . The carriage frame includes a pair of spaced apart parallel bars  82 ( a ) and ( b ) which are fixedly mounted to the frame  16  along a longitudinal axis. A carriage  84  engages the bars  82 , and includes a pair of sleeves  85  for slideable receiving the bars to permit the carriage  84  to slide longitudinally along the bars  82 . A reciprocating pneumatic cylinder  88  mounted at one end to the carriage  84  and at the opposing end to the apparatus frame  16  drives the carriage  84  within a longitudinal direction. Extending upwardly from the carriage  84  is a rectangular pillar  88 ′ A corresponding rectangular sleeve  90  is slideably received on the pillar and is driven vertically relative to the support by means of a reciprocating pneumatic cylinder  92  mounted to the respective members. Mounted to a side of the sleeve  90  is a second, horizontally-oriented rectangular sleeve  94 , the axis of which is in the lateral direction. The second sleeve  94  slidingly receives a beam  96 , one end of which in turn is mounted to the base of the gripper assembly  50 . Lateral reciprocating movement of the gripper assembly  50  relative to the carriage  52  is achieved by means of slidable movement of the beam  96  within the second sleeve  94 , which in turn is driven by a pneumatic cylinder  98  linking the respective members. Vertical movement of the gripper assembly  50  is achieved by operation of the pneumatic cylinder  92 .  
         [0046]    The conveyer station  54  is mounted to the carriage assembly  52  by means of a beam arrangement  100 . The conveyer station  54  comprises a pair of generally co-planer belt assemblies  102 ( a ) and ( b ). The belt assemblies  102  each comprise a housing  104 , having journalled therein a pair of rotatable pullies  106  at either end thereof, supporting the opposing ends of a rotatably driven belt  108 . A motor  110  drives both the first of the belts  108 ( a ) and  108 ( b ). The respective belts are geared together through meshing spur gears mounted on corresponding belt drive shafts. The first housing  104 ( a ), with the motor  110  mounted thereto, is fixed to the beam arrangement  100 . The second housing  104 ( b ) is pivotally mounted to the beam arrangement  100  for pivoting about a vertical axis. When the respective housings  104 ( a ) and ( b ) are swung together within the closed position, the respective belts  108 ( a ) and ( b ) are parallel to and in substantial contact with each other. Within the open position shown in FIG. 3, the belts  108  diverge. When in the diverged position, the belts are able to receive a filled bag, and subsequently swing together in to the closed position for conveyance of the bag away from the apparatus.  
         [0047]    Operation of the devise will now be described by reference to FIGS.  107 ( a )-( i ).  
         [0048]    Operation of the apparatus commences with an individual bag  110 , comprising the first bag in the interconnected array of bags  46 , being supported by the wicket members  44  and positioned directly below the hopper  28 . An air nozzle  112  mounted to the wicket support  43  directs a stream of air into the at least partly open mouth of the bag  110 , to open the bag sufficiently for filling and to hold the bag open as the jaws  36  and  38  of the hopper  28  descend into the bag  110 , as shown in FIG. 7( b ). The hopper  28  then discharges a measured amount of the commodity into the bag  110 . As the hopper is discharging the commodity, the bag gripper assembly  50  advances laterally towards the hopper  28 , as seen in FIG. 7( c )-( e ), and subsequently downwardly, as seen in FIG. 7( f ), such that the downwardly-depending fingers  67  of the inner arms  66  extend into the open mouth of the bag  110 . The jaws  36  and  38  of the hopper  28  then close and the hopper moves upwardly, as shown in FIG. 7( g ) and ( h ). Simultaneously, the inner arms  67  of the gripper diverge, thereby drawing taut the mouth of the bag  110  and gripping opposing corners of the bag between the respective inner and outer fingers  64  and  67 , as seen in FIG. 7( h ). The gripper assembly  50  then retracts laterally, as seen in FIG. 7( i ), and transfers the bag  110  longitudinally to the conveyer station  54 . Retraction of the first bag  110  away from the interconnected array of bags  46  draws the subsequent bag  111  in the array forwardly in position beneath the hopper  28 . The filled bag  110  is then conveyed longitudinally along the paired bars  82 , towards the conveyor station  54 . The paired belts  108  of the conveyer station  54  within the open position receive the bag  110 , and subsequently converge to grippingly engage the bag between the respective belts  108 , for conveyance towards a heat sealing station  120  or the like. Conventionally, the heat sealing station comprises a pair of heated belts  122  which may receive the bag directly from the conveyer to perform a heat sealing operation on the bag.  
         [0049]    Operation of the device, and in particular, operation of the various pneumatic cylinders, is controlled by a central control unit, which in includes sensors for detecting the positions of the various components referred to above, and ensuring the various pneumatic actuators operate in a coordinated fashion.  
         [0050]    It will be seen that although the present embodiment employs reciprocating pneumatic actuators for driving the various components of the apparatus, any known drive means may be substituted, including hydraulic rams, electric linear actuators or other like means.  
         [0051]    It will be further understood, that although the present invention has been described in detail by way of a preferred embodiment thereof, persons skilled in the art to which this invention pertains will be able to make numerous modifications and variations to the invention. These variations and modifications will still remain within the spirit and scope of the invention, which is described and characterized within the appended claims.