Abstract:
A method and system for packaging batches of elongate, non-symmetrical products that are soft and/or flexible in nature, such as fish, in which the products are arranged in mutually reversed orientations for maximized utilization of package space. The products are weighed for determining their individual weights and a computerized control is used to selectively accumulate the products on the basis of product weight and other predetermined criteria, to merge the products into groups, and to automatically deposit the products into boxes with a mutual reversed orientation.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the batching or grouping of products, such as whole fishes, which are elongate and asymmetrical about their middle, typically with reference to packings appearing as simple boxes, e.g., of expanded polystyrene, with a content of a higher or smaller number of fishes in two or more layers, or perhaps not strictly made up of neat layers. 
     2. Description of Related Art 
     Salmon is a typical example of fish handled in the initially mentioned manner, packed with or without their heads intact. Fish in such packings are usually accounted for in terms of weight, for delivery, e.g., to slicing enterprises or large kitchens. For the building up of reasonably compact packings, it is considered important to arrange the fishes in the boxes so that they are oriented in mutually opposite directions in at least approximately equal numbers, whether or not distributed strictly layer-wise in the box. Hereby, the top side of the packed goods will be substantially level, irrespective of the products being narrower at one end than at their opposite end, and thus, the boxes may be loaded in a compact manner. 
     Traditionally, the associated weighing, orienting and packaging operations have been carried out fully manually, with inherent possibilities of producing packings of approximately uniform weight and size as desirable from a customer&#39;s point of view, a.o., for facilitating the associated accounting. 
     However, it is already known that the weighing-out of the products, for a building up of desired total target weight portions in a plurality of receiver stations, can be based on a grader technique, according to which the products are serially supplied to a dynamic weighing station and, therefrom, conveyed further along a sorter line including a plurality of receiver stations and diverter means operable to divert products selectively into any of these receiver stations, controlled by a computer connected with the weighing station. Once informed of the desired target weight or even different weights, the computer will be suited to control the sorting out of the products in such a manner that each receiver station will automatically receive products building up to the relevant target weight or weight range. This is highly facilitating for the required manual work, and it is advantageous for the producer, not only because of the reduced need of manual activities, but also because the resulting packings are much more likely to really hold the target weight, without undue overweight or so-called “give-away”. 
     Thus, practically the only remaining manual activity will be to arrange the products in the individual portions or packings such that the products are oppositely oriented as mentioned above, just implying a turning of some of the products lengthwise. This does not require any particular skill, so generally the use of the said grader technique is highly advantageous. 
     In connection with the present invention, however, it has been realized that the said computer may in fact be utilized even for effecting a qualified turning of a relevant number of products in the individual portions, thus obviating even the said unskilled manual work. 
     SUMMARY OF THE INVENTION 
     At its outset, the invention is based on the idea that, once the computer has decided into which receiver station a given product should be delivered, it will be operable to also hold information as to the orientation of the products previously allocated to that particular receiver station. Thus, basically, it could convey a message to an operator, indicative of “please turn this fish”, but in practice, it is highly preferable, according to the invention, to arrange for mechanical turning means operable to effect the required turnings based on the knowledge of the computer with respect to the sequential delivery of products to the individual receiver stations. In this manner, it will be possible to effect a relevant turning, e.g., of every second allocated product or of any number of successively allocated products to any receiver station such that the result will be packings in which approximately one half of the products are turned in an opposite direction with respect to the other approximate half, whether or not being arranged in specific layers. 
     This principle is based on the computer instituting operations resulting in a turning of a partial number of products or rather a “relative turning” thereof, in order to achieve the desired result. For example, the computer could control some of the products to be turned 90° in one direction, while all other products are turned 90° in the opposite direction. Such turnings can be effected in a variety of different ways as discussed in more detail below. 
     According to another aspect of the invention, mechanical turning means can be entirely avoided, provided it is ensured beforehand that the products as delivered to the weighing station, e.g., on a conveyor belt, are already arranged systematically with alternating orientations, irrespective of how this has been arranged for. One possibility is the use of a feeder belt passing a loading station in which two operators place on the belt respective products with the same orientation, yet with mutually opposite orientations, in an alternating manner. The grader computer, now not being able to effect product turning, nevertheless will have at disposal for the batching calculations, a flow of products of which some are already turned, i.e., it can determine relevant allocations with an associated selection of correctly oriented products. “Correct orientation,” here, will be opposite orientation relative to the foregoing product allocated, respectively, to each of the individual receiver stations. For high efficiency, this kind of operation may require an increased number of receiver stations. 
     According to a further aspect of the invention, it is not strictly necessary to make use of the grader computer for other than its ordinary purpose, because a further possibility will be to arrange at each receiver station a “product arrival sensor” operatively connected with an associated local turning device in such a manner that every second product will be automatically turned before delivery to the final product batch. These devices may, as well as the computer, be programmable so as to effect turning of any preset number of consecutive products following any number of consecutive unturned products and prior to receiving further consecutive unturned products in the respective individual receiver stations. 
     It should be noted that the invention is not limited to the said “batching to predetermined weight”, as it will apply equally to mere sorting operations or to the weighing out of product portions according to other criteria, e.g., “batching to minimum weight,” which implies that batching goes on until a preset minimum weight has been reached, no matter the surplus or give-away weight involved for the attainment of the minimum weight. Such a batch, normally for delivery to a specific customer, may well comprise a number of different products according to specified orders, e.g. specified numbers of salmons from specified weight ranges with a top filling of smaller salmons up to a total minimum weight. 
     In the following invention is described in more detail with reference to the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of an embodiment of a system according to the invention, 
     FIGS. 2-7 are similar views of further embodiments, FIG. 8 is a perspective view of a particular turning arrangement, 
     FIGS. 9 and 10 are views corresponding to FIGS. 1-7 of modified systems according to the invention, 
     FIG. 11 is a perspective view of a relevant product receiving station, and 
     FIG. 12 is a side view of a relevant box filling station. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In FIG. 1 the basic principle of the invention is illustrated. The basic sorter/grader apparatus is shown, comprising an inlet feeder conveyor  2 , a dynamic weighing station  4  with an associated weighing computer  6 , and an after-coupled sorter conveyor  8  which passes along a row of receiver stations  10 , each associated with diverter means, such as an oppositely arranged wing member  12 , which can be swung inwardly over the belt  8  as shown at  12 ′ in order to effect diversion of a conveyed article  14  into any selected receiver station  10 . Such a selection is effected by the computer  6  which, via a control line  16 , serves to selectively actuate the diverter wings at appropriate moments of time for diverting specific articles  14  to specific receiver stations  10 . In this way, it is possible to build-up, in each receiver station, a batch of products  14  with a precisely determined accumulated weight, whether such weight being a predetermined target weight or just a registered weight of, e.g., a certain number of fish, or a weight fulfilling some minimum weight criterion. 
     Between the weighing station  4  and the sorter belt  8 , there is provided a belt section  20  which is mounted on a horizontally rotatable support structure  22 , to the effect that the individual fishes can pass to the conveyor  8  either straightly or turned 180°, governed by the computer  6 . On the feeder conveyor  2  the fish  14  are supplied with uniform orientation, preferably “head first,” and during the operation, it will thus be possible to rearrange some of the fish into a “tail first” position, as shown  14 ′. 
     As soon as a fish has left the weighing station  4 , the computer  6  will know to which receiver station  10  the fish is allocated. If this particular station is empty, whether by initial starting up or after emptying of the station upon the building up of a previous full batch, the first fish or few fish may pass to that station with unchanged orientation, but thereafter, when one or few further fish are allocated to the same station  10 , it will be actual to effect a turning of that or these fishes, and the computer  6  will serve to actuate the turner structure  22  correspondingly, turning the belt  20  and reversing its moving direction such that, after the turning, it will still deliver the fish further to the sorter belt  8 . 
     In normal operation, the fish will be delivered to the individual receiver stations rather irregularly, but despite this irregularity, the computer  6  will steadily keep track of the orientation of the fish lastly allocated to each particular receiver station. In this way, it is easily determined automatically whether an actually weighed-in fish should be turned or not in order to contribute to the desired shape of the batch, to which this particular fish is allocated. 
     While FIG. 1 will thus illustrate the principle of the invention, this system will not be particularly advantageous in practice, because turning of the structure  22  will take some time, whereby the flow of the fish cannot be particularly rapid. In practice, therefore, it is preferred that the relevant turning be effected upon the arrival of the fish to the individual receiver stations, as illustrated in FIG. 2, by the inclusion of a turning structure  24  in each single receiver station. On the conveyor  8 , the fish will then proceed with unchanged, uniform orientation, and the computer will operate the different turning structures  24  in a selective manner, in accordance with the sequential allocation of fishes to the individual stations  10 . 
     In FIG. 3, a similar result will be achieved, but in this case, the turning structures are not operated by the computer, but by means of local control units  26  in connection with respective sensors  28  detecting the arrival of a fish to the associated station  10 . The control may be very simple, as each of the turning structures  24  may be methodically turned 180° in connection with the passage of every second fish to the respective stations  10 . On the other hand, the control units  26  may be set so as to control the turnings for the building up of layers with any number of fish turned one way and the other, respectively. 
     FIG. 4 is a modified version of FIG. 1, illustrating that, while the fish are still fed to the weighing station with longitudinal orientation in the feeding direction, the turning structure  22 ′ may be controlled so as to effect turning of the fish through 90° only viz, turning the “turn selected” fish 90° in one direction and turning all other fish 90° in the opposite direction. Thereby, the fish will be transferred to the sorter belt  8 ′ with a crosswise orientation, but otherwise turned as required for correct delivery to their respective destinations. This will or may imply that even the receiver stations may be orientated generally crosswise of the conveying direction, whereby they can be arranged with reduced mutual spacing along the sorter conveyor. Of course, the turning structure  22 ′ should be made so as to enable the fish to be let out crosswise to the in-feeding direction, with the use of pusher means or otherwise. 
     In FIG. 5, a system is illustrated that will not require any movable turning means. Each effective receiver station A, C and D comprises two distinct receiver openings  30  and  32  arranged one after the other along the sorter belt  8 ′ and each connected to respective chutes  34  and  36  leading to a collector station  38 . In station A, chute  36  is arranged so as to guide a fish  14  from the opening  32  first forwardly, then outwardly and finally rearwardly for delivery of the fish, now turned 180°, to the collector station  38 , while the chute  34  delivers fish from the opening  30  directly to that station  38 . Thus, for each receiver station, the computer  6  will arrange for delivery of fish selectively to the two openings  30  and  32  in order to effect the relevant relative turnings. 
     FIG. 5 also shows, in station C, an alternative arrangement, with the openings  30  and  32  located at opposite sides of the belt  8  and with the chutes  34  and  36  extending so as to effect feeding to the collector station  38  from opposite ends thereof, that station  38  here being arranged underneath the belt  8 . The chute  34  will turn the fish through 180°, while in chute  36  they will be turned through 360°. In station D is shown a further alternative, by which the chutes  34  and  36  both turn all fish by 90°, yet again in respective opposite directions, whereby the fish are merged as required in the crosswise arranged collector station  38  underneath the belt  8 . 
     Finally, in station B, it is shown that it may be superfluous to make use of two inlet openings to each receiver station, as the fish may be guided through the respective chutes from a single opening  33 , with the use of a computer controlled switch plate  35 . 
     In the grader technique, it is already known that it is possible to place two receiver stations  10  right opposite to each other, at opposite sides of the sorter belt  8 , and still operate them in a selective manner. This, of course, will be another alternative to the systems shown in FIG. 5, instead of the receiver openings  30 ,  32  being staggered along the belt. On the other hand, with the use of chutes, it will, in principle, be a simple matter of choice which two receiver openings should belong to a given collector station  38 ; the openings need not even be neighbors. 
     In FIG. 6, it is suggested that the turning structure be constituted by a pair of plates or small belt conveyors  40  operable to receive a fish between them and then to be rotated through 180° about the transverse, horizontal middle axis a of this assembly, whereby the fish, in being turned upside down, will also be turned to an opposite orientation as required in a system according to FIG.  1 . The structure  40  could be replaced by a tubular member. 
     FIG. 7 shows a similar arrangement in connection with the conveying of the fishes with crosswise orientation. In this case the said middle axis should be the longitudinal axis. The resulting selective turnings will be relevant for the operation of a sorter conveyor  8 ′ as in FIG.  4 . 
     In order to increase the handling capacity of such a system, it is possible to make use of a number of transfer devices as shown schematically in FIG.  8 . Here, as an example, four rotary discs  44  are arranged on or in a common carrier plate  46  mounted in a vertical plane just outside the discharge end of the weighing station  4 , rotatably about a center bearing  48 . Each disc  44  has a rectangular through-hole lined with a short tubular frame structure  50  suited to receive a crosswise disposed fish from the station  4 , when assuming an uppermost, horizontal position. By rotating of the carrier plate  46 , the frame  50  can be swung down to a lower position just in front of the sorter conveyor  8 , and the fish housed in the frame structure, now with inverted orientation, can be pushed out onto the conveyor  8  by means of a suitable pushing element  52 . Actuator means (not shown) are provided for selectively rotating the discs  44  through 180° relative to the carrier plate  46  while they move from the upper to the lower position, as indicated by the frame designated  50 ′, this frame having been turned 90° since it left the said upper position. It will turn a further 90° until it reaches the lover position, and thus, the fish will, in this case, be brought to enter the conveyor  8  without having changed its orientation. Thus, the turning/non-turning operations can be effected dynamically during the conveying of the fish, such that the product flow can remain high. 
     FIG. 9 illustrates the above mentioned possibility of arranging the fish  14  on the feeding conveyor  2  with alternating orientations, which are maintained throughout the passage of the fishes through the weighing station  4  and along the sorter converter  8 . The computer  6 , in order to determine the allocation of a fish of a specific, suitable weight to any individual receiver station  10 , will enable such an allocation only if the new fish is oriented correctly for such an allocation, compared with the orientation of the fish delivered to such a selected receiver station. If the new fish is rejected for this reason, the computer will seek to allocate it to another receiver station, in which its orientation is acceptable, and of course, also its weight, even if its weight is not exactly the best choice for an ideal allocation. 
     As mentioned, the alternating orientation of the fish on the feeder conveyor  2  may be a result of a manually controlled loading of this conveyor, but another possibility is to feed the system with products of uniform orientation and then automatically effect an inversion of every second or some other number of consecutive products, e.g., according to published European Patent Application EP-A-0 359 824, before the products entering the weighing station  4 . The determination of which products should there after be inverted for the purpose of the invention, with its associated irregular input to the individual receiver stations, will then be the domain of the present invention, whatever principle it is based upon. 
     In FIG. 10, an alternative is shown, in which the products  14  are arranged with uniform orientations crosswise of the feeding conveyor  2 . After the weighing station  4 , the products are passed to a further, short and broad conveyor  5 , above which there is mounted a transversely reciprocal system comprising two opposed arms  7  which, in an alternating manner, can be brought to project slightly into the conveying path of the products whereby these, owing to their friction with the conveyor belt, will be turned as illustrated, through somewhat less than 90° With the alternating operation of the arms  7 , the products will thus be turned to assume almost opposite orientations, sufficiently for the purpose of the invention. 
     A preferred system according to the invention is the one illustrated in FIG.  2  and for that sake in FIG. 3, involving the use of individual turning means  24  associated with each of the receiver stations  10 . These turning means may be designed in a variety of different manners. In a basic embodiment, they will merely be means for supporting the final product boxes in a turnable manner, such that the products can be delivered to the boxes directly from the conveyor  8 . However, this is not too advantageous for the capacity of the system, because each receiver station will then be inoperative during the turning of the boxes and during periods in which a finished box is removed and replaced by a new box. It is preferred, therefore, to use an intermediate buffer container, and such a system, by way of example, is shown in FIG.  11 . 
     FIG. 11 shows the weighing station  4 , the sorter conveyor  8 , and a single receiver station  10 . This station comprises a collector bin  54  mounted on a fixed rail  56  at the side of the conveyor  8 , the bin having a sloping bottom leading to an openable end stop wall  58  that is hinged to the sides of the bin at  60 . Also mounted on the rail  56  is a pivot pin  62  for a diverter wing  64  operable to be swung between the active position shown and a position closing the entrance to the bin. 
     During normal operation, the stop wall  58  will be open, whereby allocated fish will pass to an underlying box member  66 , which is rigidly mounted on a rotatable disc  68  and provided with a bottom valve plate  70  which is retractable by means of a cylinder  72  in order to open the bottom entirely. The disc  68  is in driving engagement with a motor  74  operable to rotate the disc through 180°. The structure  68 , 74  is supported by a machine chassis (now shown). 
     A packing box  76  is placed underneath the plate  68 , and a similar box  76 ′ may be placed so as to be ready to be displaced into this position when the box  76  has been filled. 
     Based on the description of FIG. 2 it will be readily understood that once the box member  66  has received as many fishes as preset to be allocated with a first orientation, the bottom plate  70  can be opened for dropping these fish down into the box  76 . During this operation with associated reclosing of the bottom plate  70 , the stop wall  58  is held closed so that the receiver station is still capable of receiving further allocated fish to a certain extent. The stop wall  58  is reopened as soon as the bottom plate has been closed, and then, the next partial number of fish, adapted for delivery to the box  76  with inverted orientation, is collected in the box member  66 . Then, the stop wall  58  is closed, and the motor  74  is actuated for rotating the box  66  through 180°, whereafter the cylinder  72  is actuated to open the box bottom, and thus, drop the fish onto those dropped in the first place. Collection of the next following number of fish can start as soon as the bottom plate  70  has been re-closed; there is no need to first return the box member into its original position, as such a returning can wait until the next fish turning becomes due. 
     When the box  76  has been filled to the relevant degree, it is pushed out to the position  76 ′, e.g., for delivery to a conveyor  78 , and at the same time, the box  76 ′ will be displaced to the filling position. During these shifting operations, the box member  66  may well start receiving the first partial number of fish for the new box  76 . If the shifting has been completed before this new number has been fully counted, then the new operation can proceed as described above; otherwise, it may be required to effect closing of the stop wall  58  and initiate accumulation of the next following partial number in the bin  54 . Upon completion of the shift, the box bottom  70  should be opened and closed for dumping of the first partial number of fish in the new box, whereafter the stop wall  58  can be reopened. 
     If desired, one or more additional buffer boxes can be arranged. Also, this or these boxes may be large enough to hold as many fish as the boxes  76 , since it is then a possibility to arrange a complete box portion in the buffer box, turning the same as required without opening the bottom plate  70 . In this manner, e.g., in connection with a temporary operation stop at the exit end of the system, it is possible to continue the portioning-out at full capacity during some time, building up full portions in both the boxes  76  and the buffer boxes  66 , even followed by an initial collection in the bins  54 . Even in normal operation, it may be chosen to buildup the whole box contents in the turnable buffer boxes, and thus, to fill up the boxes  76  by one fast dumping operation. 
     Instead of the row of boxes  76  as shown in FIG. 11, it may be preferred to use a conveyor belt  80  as exemplified in FIG.  12 . This belt is provided with upstanding entrainment plates  82  capable of holding between them the full charge for a box  76  placed at the exit end of the conveyor  80 . Thus, the whole charge will be dumped into the box, obviously without any particular stratification with reference to the orientation of the fish. This, however, is of minor importance as long as the numbers of fish with respective opposite orientations are substantially equal. 
     It should be mentioned that the invention may be applied also to the weighing-out technique denoted “combinatory weighing”, where products are diverted at random to a row of weighing containers, whereafter a computer determines which of the products should be let out for being merged into a portion in which their weights will combine into a desired target weight. Also in this connection it will be possible to arrange for relevant turning of some of the products or, in accordance with the principle behind FIGS. 9 and 10, to provide for an increased number of weighing containers divided in two groups, one holding products with one orientation and the other holding products with the opposite orientation as arranged for beforehand. The computer, in determining relevant candidates of products to be merged, may then look for products having not only a relevant weight, but also a relevant orientation. 
     It should be mentioned that it will be possible to make use of sensor means such as a vision equipment to detect the orientation of the articles fed to (or leaving) the weighing station or even arriving at the individual receiver stations, whereby corresponding results may be obtained without special prescriptions as to the, orientations of the successively supplied fish.