Abstract:
A bucket elevator or conveyor comprises a plurality of removable buckets  10  each pivotally supported between two drive chains  11.  The buckets  10  are shaped such that their lips  26  overlap when they are traveling horizontally. In this manner, the buckets  10  can be filled without the risk of spillage.  
     The attitude of the buckets  10  are controlled by a guide rail  17  and this combined with shape of the leading and trailing walls  22,23  of the buckets  10  enables the buckets  10  to traverse bends in the vertical plane without interfering.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to apparatus for conveying a product in a manufacturing or production facility for example.  
           [0003]    2. Related Background Art  
           [0004]    In manufacturing or production facilities, the product (or a constituent of the product) being manufactured or produced is often conveyed between two points in a series of receptacles, which are fastened to driven chains or belts. The receptacles are filled with the product to be conveyed and the chain is driven, transporting the product to a discharge point. The receptacles are usually supported on pivots, which allow them to swing and to maintain their attitude regardless of the orientation of the chain: this allows the chain to traverse around sprockets provided at bends in the vertical plane without spilling the contents of the receptacles and also allows the contents to be emptied by tipping.  
           [0005]    Such conveyors are known as swinging bucket elevators and suffer from several problems.  
           [0006]    The receptacles are usually filled from a fixed point via a chute, whist the receptacles continuously pass underneath. A disadvantage of this is that the product can spill in the gap between adjacent receptacles. Spillage is undesirable, since it is wasteful, messy and can constitute a health hazard.  
           [0007]    The problem of spillage is further exacerbated as the chain stretches over time, which causes the space between the adjacent receptacles to increase.  
           [0008]    Many attempts have been made to solve the above-mentioned problem. However, such solutions have been complex and expensive. The problem is further complicated by the need for the chain, and hence the receptacles, to traverse around sprockets as the chain changes direction in the vertical plane, since the receptacles interfere with each other and jam if the spacing between adjacent receptacles is insufficient.  
           [0009]    Hitherto this problem has precluded the use of a common design of receptacle for conveyor configurations in which the chain either follows a Z-shaped or C-shaped path in the vertical plane. The problem prevents the receptacles from being physically attached to one another without very complex and expensive interlocking mechanisms which span the gap between adjacent receptacles.  
           [0010]    I have now devised a conveyor which alleviates the above-mentioned problems.  
         SUMMARY OF THE INVENTION  
         [0011]    In accordance with this invention as seen from a first aspect, there is provided a conveyor comprising a plurality of upwardly-facing receptacles mounted in series to means for conveying the receptacles along an elongate path, each receptacle being pivotally mounted to said conveyor means for rotation about an axis which extends perpendicular to the direction of conveyance along said path, the receptacles each comprising opposed first and second end walls extending perpendicular to the direction of conveyance, and a lip across the upper end of said first wall which extends away from said second wall and overhangs the second wall of an adjacent receptacle, the outer end of the lip depending towards the interior of said adjacent receptacle, means being provided at least one point along said path for rotating the successive passing receptacles about said axis in a direction which brings the lip of one receptacle into a position where the outer end thereof extends into the interior of its adjacent receptacle.  
           [0012]    In use, the material to be conveyed is loaded into the receptacles at the point where the receptacles are rotated. It will be appreciated that at this point, the lips bridge the gap between adjacent receptacles and thus spillage is avoided.  
           [0013]    The lips extend sufficiently far for the gaps to be bridged even when the chain or belt stretches.  
           [0014]    Under normal conditions, the lips of the receptacles only overhang their adjacent receptacle and thus the receptacles are free to move independently of each other without interfering and jamming.  
           [0015]    Preferably, each receptacle is rotated in a first direction at said point to bring its lip down onto the adjacent receptacle.  
           [0016]    Preferably the lip of each receptacle extends upwardly and outwardly from the upper end of its first wall and then outwardly and downwardly towards the interior of its adjacent receptacle.  
           [0017]    Preferably the first and second walls of each receptacle converge towards the base of the receptacle.  
           [0018]    Preferably the convergent walls curve inwardly towards each other, with the radius of curvature preferably substantially corresponding to the radius of curvature of bends in the path in the vertical plane: I have found that walls of this shape enable adjacent receptacles to be mounted very close together without the risk of them interfering and jamming as they change direction in the vertical plane.  
           [0019]    When conveyors are used in the food industry, hygiene is vitally important and the receptacles must be regularly cleaned. In order to overcome this problem it is known to provide cleaning systems. However, these are both complex and costly.  
           [0020]    It is known to operate conveyors under sub-zero temperatures conditions for conveying frozen and chilled foods. A disadvantage of this is that the conveyor has to be brought back to room temperature before it can be cleaned. This is both time consuming and costly.  
           [0021]    Thus, in accordance with this invention as seen from a second aspect, there is provided a conveyor comprising a plurality of upwardly-facing receptacles mounted in series to means for conveying the receptacles along an elongate path, the internal compartment of each receptacle being lined with a removable liner.  
           [0022]    The provision of the liner means that the receptacles do not have to be cleaned. Instead, the liners merely have to be removed and replaced with clean ones. The liners may be discarded or cleaned following use.  
           [0023]    Preferably the liners are a vacuum molding of thin plastics material.  
           [0024]    Preferably the liners are colored, so that different colored liners can be used for conveying different foodstuffs.  
           [0025]    Preferably each receptacle is pivotally mounted to said conveyor means for rotation about an axis which extends perpendicular to the direction of conveyance along said path, the receptacles each comprising opposed first and second end walls extending perpendicular to the direction of conveyance, and a lip across the upper end of said first wall which extends away from said second wall and overhangs the second wall of an adjacent receptacle, the outer end of the lip depending towards the interior of said adjacent receptacle, means being provided at least one point along said path for rotating the successive passing receptacles about said axis in a direction which brings the lip of one receptacle into a position where the outer end thereof extends into the interior of its adjacent receptacle, said liners extending over said lips.  
           [0026]    It is often desirable to be able to determine the quantity of the material in each receptacle.  
           [0027]    Accordingly, in accordance with this invention as seen from a third aspect, there is provided a conveyor comprising a plurality of upwardly-facing receptacles mounted in series to means for conveying the receptacles along an elongate path, each receptacle being suspended by said conveyor means, means being provided at least one point along said path for weighing the successive passing receptacles, said weighing means comprising a raised member arranged to abut and lift the receptacles and a sensor disposed between the member and a fixed surface and arranged to provide an output indicative of the downwards force acting on the raised member.  
           [0028]    In one embodiment, the receptacles are removably seated in mountings on the conveyor means, said raised member being arranged to lift the passing receptacles entirely out of their mountings. In this manner the downwards force acting on the member is equal to the entire weight of the receptacle. Thus, the weight of the contents of the receptacle can be determined by subtracting the tare weight of the receptacle away from the measured weight.  
           [0029]    In an alternative embodiment, the receptacles are pivotally mounted to the conveyor means, said raised member being arranged to rotatably lift the passing receptacles. Whilst the full weight of the receptacles is not applied to the member when they are pivoted, the actual weight of the receptacles can be determined using a predetermined algorithm.  
           [0030]    As hereinbefore mentioned, it is often necessary to clean the receptacles. Hitherto this has involved cleaning each receptacle whilst it is in-situ on the chain or belt. It will be appreciated that this is both difficult and time consuming.  
           [0031]    Thus, in accordance with this invention as seen from a fourth aspect, there is provided a conveyor comprising a plurality of upwardly-facing receptacles mounted in series to means for conveying the receptacles along an elongate path, each receptacle being detachably mounted to said conveyor means.  
           [0032]    Thus, in order to clean the conveyor, the receptacles can be removed, thereby simplifying the cleaning operation.  
           [0033]    Preferably, the receptacles are mounted to the conveyor for rotation about an axis which extends perpendicular to the direction of conveyance along said path.  
           [0034]    Preferably, the conveyor means comprises a pair of parallel belts or chains having a plurality of opposed pairs of supports for receiving the respective receptacles therebetween.  
           [0035]    Preferably, the receptacles are formed of molded plastics material, each side wall of the receptacles being molded with a formation which engages with a said support.  
           [0036]    The linear speed of known conveyors is restricted because as the receptacles traverse a bend in the vertical plane, they have a tendency to swing outwards with the momentum of their original movement. The severity of the swing is proportional to the linear speed of the receptacle, which leads to the receptacle spilling its contents at elevated speeds.  
           [0037]    Accordingly, in accordance with this invention as seen from a fifth aspect, there is provided a conveyor comprising a plurality of upwardly-facing receptacles mounted in series to means for conveying the receptacles along an elongate path, each receptacle being pivotally mounted to said conveyor means for rotation about an axis which extends perpendicular to the direction of conveyance along said path, and a guide coextending with the conveyance means around at least bends in the path in the vertical plane, means being provided on the receptacles for engaging the guide to control the pivotal movement thereof.  
           [0038]    The guides thus act to prevent the receptacles from pivoting unduly as they traverse bends in the path.  
           [0039]    Preferably the receptacles comprise a body portion defining a compartment for receiving the material to be conveyed and a support portion pivotally mounted to the conveyance means, said guide engaging means being provided on the support portion.  
           [0040]    In order to control the attitude of the buckets as they travel horizontally, said guide engaging means preferably engages the guide at points disposed forwardly and rearwardly of the pivotal axis of the receptacles.  
           [0041]    In order to control the attitude of the buckets as they travel vertically, said guide engaging means preferably engages the guide at points disposed above and below the pivotal axis of the receptacles.  
           [0042]    Preferably the guide is arranged to vary the attitude of the receptacle as it traverses a bend in the vertical plane, in order to further alleviate any risk of the receptacles interfering or jamming as they traverse the bend.  
           [0043]    Preferably the guide is arranged to at least partially invert the receptacles at an unloading point along the path.  
           [0044]    Preferably the receptacles each comprise opposed first and second end walls extending perpendicular to the direction of conveyance, and a lip across the upper end of said first wall which extends away from said second wall and overhangs the second wall of an adjacent receptacle, the outer end of the lip depending towards the interior of said adjacent receptacle, the guide being arranged at point on the conveyor to rotate the successive passing receptacles about said axis in a direction which brings the lip of one receptacle into a position where the outer end thereof extends into the interior of its adjacent receptacle.  
           [0045]    Preferably, each receptacle is rotated in a first direction at said point to bring its lip down onto the adjacent receptacle.  
           [0046]    In known conveyor systems, there is a problem that the receptacles will not always fill in a uniform manner from a chute. Some materials will heap in one part of the receptacle and will not flow and level. It is important that the receptacles fill in a uniform manner, so that the receptacles can be fully filled and the conveyor can operate at high efficiency with a wide range of materials.  
           [0047]    Accordingly, in accordance with this invention as seen from a sixth aspect, there is provided a conveyor comprising a plurality of upwardly-facing receptacles mounted in series to means for conveying the receptacles along an elongate path, each receptacle being suspended by said conveyor means, means being provided at at least one point along said path for settling the contents of successive passing receptacles, said settling means comprising a member arranged to abut the receptacles and means for vibrating the member.  
           [0048]    The vibration of the receptacle automatically levels and settles the contents of the passing receptacles, irrespective of the type or makeup of the material. To further increase the leveling efficiency, the frequency of the vibration can be adjusted to suit the particular material being carried, this can easily be achieved by those skilled in the art.  
           [0049]    Preferably, the settlement means is disposed at a point where the receptacles are filled.  
           [0050]    Preferably each receptacle is pivotally mounted to said conveyor means for rotation about an axis which extends perpendicular to the direction of conveyance along said path, a guide co-extending with the conveyance means along at least a portion of the path, means being provided on the receptacles for engaging the guide to control the pivotal movement thereof, said vibrating means being arranged to vibrate a portion of the guide.  
           [0051]    Preferably the member at least partially supports said passing receptacles. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0052]    An embodiment of this invention will now be described by way of an example only and with reference to the accompanying drawings, in which:  
         [0053]    [0053]FIG. 1 is a schematic side view of an embodiment of conveyor in accordance with this invention in a C-shaped configuration;  
         [0054]    [0054]FIG. 2 is a schematic side view of an embodiment of conveyor in accordance with this invention in a Z-shaped configuration;  
         [0055]    [0055]FIG. 3 is a perspective view of a receptacle of the conveyor of FIG. 1 or FIG. 2;  
         [0056]    [0056]FIG. 4 is a sectional view along the line IV-IV of FIG. 1 or FIG. 2; and  
         [0057]    [0057]FIG. 5 is a sectional view along the line V-V of FIG. 4;  
         [0058]    [0058]FIG. 6 is a side view illustrating how the attitude of the receptacles of the conveyor of FIG. 1 or FIG. 2 is maintained;  
         [0059]    [0059]FIG. 7 is a sectional view along the line VII-VII of FIG. 6;  
         [0060]    [0060]FIG. 8 is a side view illustrating how the attitude of the receptacles of the conveyor of FIG. 1 or FIG. 2 is varied; and  
         [0061]    [0061]FIG. 9 is a sectional view along the line IX-IX of FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0062]    Referring to FIGS. 1 and 2 of the drawings, there is shown a conveyor comprising a plurality of receptacles or so-called buckets  10  each mounted between a pair of spaced parallel endless drive chains  11 , which pass over sprockets  12  and  13  at opposite ends of the conveying line.  
         [0063]    The chain  11  passes around intermediate sprockets  14  as the chain changes direction in the vertical plane. In this manner a plurality of different configurations of the conveyor can be achieved, as shown in FIGS. 1 and 2.  
         [0064]    A motor (not shown) is drivably connected to the shaft of one the sprockets  12 , 13  in any suitable manner to cause predetermined uniform travel of the chains  11  in a direction A. On the bottom run of the conveyor, there is a loading station  15  where the product to be conveyed is loaded into the buckets  10  of the conveyor. Thereafter the buckets  10  travel along the conveyor to a discharge station  16  on its upper run.  
         [0065]    As will be described hereinafter, the buckets  10  are pivotally mounted between the drive chains  11  for pivotal movement about respective rotational axis which extend perpendicular to the direction of movement A.  
         [0066]    During the course of travel of the buckets  10  along the conveyor their attitude is controlled by a guide rail  17  which co-extends with one of the chains  11 , at a position which is slightly below the chains  11  when the chain is running longitudinally and which is slightly to one side of the chain  11  when the chain  11  is running vertically.  
         [0067]    The guide rail  17  is engaged by a cam  20  mounted to a support portion of the buckets  10 . At the loading station  15 , the cams  20  of the buckets  10  abut a separate member  18 , which co-extends with the guide  17  and which is connected to a motor  19  arranged to vibrate the member  18  whilst the buckets  10  are being filled.  
         [0068]    At a further point on the conveyor (not shown) the cams  20  on the body of the passing buckets  10  may abut another separate member which rotates the passing buckets  10  slightly. The downwards force applied by the buckets  10  to the member is transferred to a load cell which provides an indication of the force. From this, the actual mass of the material in the bucket  10  can be calculated using an algorithm which takes account of the fact that a portion of the mass of the bucket  10  is applied to the chain via the pivot supports of the bucket  10 . The algorithm also takes account of the tare weight of the bucket  10 .  
         [0069]    Referring to FIG. 3 of the drawings, the buckets  10  comprise a one-piece body portion  21  formed of molded plastics material and having front and rear walls  22 ,  23 , opposite side walls  24 , and a bottom wall  25 , defining an interior compartment having an open top.  
         [0070]    The opposite side walls  24  lie parallel to each other and are generally triangular in shape. The front and rear walls  22 ,  23  diverge away from the bottom wall  25  towards the open top. The side walls  22 ,  23  are in fact slightly concave in their vertical cross-section, with the radius of curvature being substantially equal to the radius of the sprockets  12 ,  13 ,  14 .  
         [0071]    A lip  26  extends across the upper edge of the rear wall  23 . The lip  26  extends upwardly and then turns outwards before turning vertically downwardly at its outer end.  
         [0072]    A pair of upwardly-extending lugs  27  project outwardly from the upper edge of opposite side walls  24  of the body  21 .  
         [0073]    The outer surface of each side wall  24  is also formed with a recess  28 , which extends from the lower end of the side wall to the upper end and increases gradually in depth.  
         [0074]    Referring to FIGS. 4 and 5 of the drawings, each bucket  10  further comprises a support assembly attached to the opposite side walls  24  of the body  21  of the bucket  10 . The support assembly comprises a pair of tubular bushes  29  which respectively receive opposed support pins  30  projecting inwardly from the respective chains  11  towards the center of the conveyor.  
         [0075]    The inner end of each bush  20  is connected to a flat plate  31  mounted normal to its longitudinal axis. The plates  31  are dimensioned to fit into respective recesses  28  formed on opposite side walls  24  of the body  21  of the buckets  10  by sliding the body  21  vertically downwards between the plates  31  until the upper edge of the plates  31  abut the upper end edges of their respective recess  28 .  
         [0076]    Each plate  31  carries a pair of upwardly-extending jaws  32 , which are pivotally mounted at their lower ends to the lower end of the plate  31  at  33  for rotation about an axis which extends perpendicular to the plane of the plate  31 . The jaws  32  are geared to each, so that they move apart when one jaw  32  is pivoted. The upper ends of the jaws  32  are spaced apart and extend beyond the upper edge of the plate  31 . The jaws  32  each have an upper end edge which is inclined inwardly and downwardly and is arranged to abut a respective side edge of the lug  27  on its respective side of the body  21  of the bucket  10 . A spring  34  extends between the jaws  32 .  
         [0077]    As the body  21  of the bucket  10  is mounted to the support, the upper ends of the jaws  32  are forced apart against the bias of the spring  33  as they abut the lugs  27 . Once fully mounted, a surface of the outer ends of the jaws  32  engage over the upper surface of the lugs  27 , thereby securely retaining the body  21  of the bucket  10 .  
         [0078]    As hereinbefore described, the support of the buckets  10  comprises a cam  22  which consists of two identical cam portions  35 ,  36  mounted back-to-back on the bush  29  on one side of the support assembly.  
         [0079]    Each cam portion  35 ,  36  comprises a flat trapezoidal or diamond-shaped plate which is mounted at its center on the bush  29 , in a plane which extends normal to the bush  29 . The cam portions  35 ,  36  are elongated in one axis only, such that they have a longitudinal axis which is greater than their transverse axis. The corners at opposite longitudinal ends of the cam portion are rounded.  
         [0080]    One of the cam portion  35  is mounted to the bush  29 ., such that its longitudinal axis lies at approximately 45° to the horizontal when the bucket  10  is in its normal upwardly-facing attitude on the conveyor. The other cam portion  36  is mounted at 90° to the first cam portion  35 .  
         [0081]    It will be appreciated that the cam portions  35 ,  36  thus provide the cam  22  with four lobes lying at 90° to each other around the bush  29 .  
         [0082]    When the buckets  10  are traveling horizontally along the upper or lower runs of the conveyor, the lowermost lobes of the cam portion  35 ,  36  abut the guide rail  17  and thereby prevent the buckets  10  from rotating in opposite senses respectively and keep the bucket  10  in a generally upright attitude as it travels horizontally.  
         [0083]    As a bucket  10  traverses a corner in the vertical plane, its leading lowermost lobe leaves the guide rail  17  and at the same time, one of its uppermost lobes abuts the guide rail  17 , thereby maintaining control over the attitude of the bucket  10 . As the bucket  10  moves further around the bend, its lagging lowermost lobe leaves the guide rail  17  and the lobe below the uppermost one already on the rail  17  abuts the rail  17 . The two vertically aligned lobes now in contact with the rail  17  prevent the buckets  10  from rotating in opposite senses respectively and keep the bucket  10  in a generally upright attitude as it travels vertically.  
         [0084]    Referring to FIGS.  6  to  9  of the drawings, it will appreciated that the cam portions  35 ,  36  lie in different planes which are slightly spaced apart. The attitude of the buckets  10  can thus be varied by arranging the guide rail  17 , so that the two lobes abut respective portions of the guide rail  17  which are set in different planes.  
         [0085]    Accordingly, at the filing station  15 , the lobes of the cam portions  35 ,  36  respectively abut surfaces of the member  18  which are in different planes to rotate the buckets  10  into a position where their lips  26  engage over the front wall  22  of their adjacent bucket  10 . Thus, the lips  26  sealingly span the gap between adjacent buckets  10  and prevent the material that is being loaded into the buckets  10  from being spilled. The buckets  10  then rotate back into the fully upright position, where they are free to move independently of each other.  
         [0086]    Similarly, the lobes of the cam portion  35 ,  36  can respectively abut surfaces of the guide rail  17  which are in different planes as the buckets  10  traverse corners in the vertical planes, so that the attitude of the buckets  10  are controlled in a manner which prevents them from interfering and jamming as the corners are traversed. The concave shape of the front and rear walls  22 ,  23  of the buckets  10  also help to avoid interference and jamming, thereby enabling the buckets  10  to be closely spaced on the conveyor.  
         [0087]    At the discharge station  16 , the cam portion  35 ,  36  again respectively abut surfaces of the guide rail  17  which are in a different plane, so that the buckets  10  are rotated into an empty position.  
         [0088]    Referring again to FIG. 5 of the drawings, a vacuum formed disposable plastics liner  40  may be provided for fitting inside the body  21  of each bucket  10 . The liner  40  has a corresponding shape to the body  21  and is provided with a lip  41  which extends over the lip  26  of the body  26 .  
         [0089]    The liners  40  thereby keep the body  21  of each bucket  10  clean and avoid the need to clean the bodies  21  as regularly. The liners  40  can easily be removed and discarded if necessary. The body  21  of each bucket  10  can be removed for cleaning by releasing the jaws  32 .  
         [0090]    A conveyor in accordance with this invention is relatively simple in construction, yet provides an efficient way of conveying material between two points which does not suffer from the disadvantages of known conveyors.  
         [0091]    While the preferred embodiment of the invention has been shown and described, it will be understood by those skilled in the art that changes of modifications may be made thereto without departing from the true spirit and scope of the invention.