[0001] The present invention is an improved fishbox.
 
            [0002] Fishboxes are the open-topped, generally rectangular containers in rich fresh fish
               are held during the time between their being caught and subsequently sold. Modern
               fishboxes are usually unitary structures moulded in a plastics material, especially
               HDPE, and are often designed so that several fishboxes may be nested in one relative
               orientation but may be stacked by turning alternate superimposed boxes through an
               angle of 180 degrees.
 
            [0003] The contents of fishboxes are inevitably wet. In addition, during some at least of
               the time in which the fish are contained in the box, it is common to preserve the
               fish in a cool condition by packing them in ice. For example, the fish may be stored
               in this way during their transit from the off-shore point at rich they are caught
               to the eventual on-shore point of sale. Since the ice melts to a greater or lesser
               extent during that time, the melt-water produced would remain in the fishboxes if
               provision were not made to drain the water from the boxes. However, if the method
               used to drain the water is simply to provide drain-holes in the base of each box,
               then water from the upper boxes in a stack of filled boxes drains through the lower
               boxes and becomes progressively more tainted as it drains.
 
            [0004] It has therefore been proposed to construct fishboxes in such a way that liquid in
               each box is directed towards the ends and/or comers of the box and is there either
               encouraged to overflow down the outer face of each box or caused to flow downwardly
               through vertically aligned drain-holes in the stacked fishboxes. While such fishbox
               constructions do indeed divert melt-water from the box below, they are not wholly
               free of disadvantages. First of all, some fish-boxes of this type do still allow some
               of the water from one box to enter the box below, at least in some conditions. Forthcoming
               regulations may require that fishboxes be so designed that this drainage from one
               box to another is not possible. Secondly, in fishboxes which have been designed to
               overcome these problems, the floor of the box has an upwardly-convex surface to drain
               the water to the ends and/or comers of the box; floors of this shape are liable to
               distort into a concave orientation under pressure of the contents of a full box, possibly
               reinforced by the weight of the fish in the box above. This distortion can occur even
               when the box floor is provided with a support rib on its underside. Modification of
               the floor cross-section to impart additional rigidity may require an irregular upper
               convex surface, which in turn can mark or damage the stored fish in contact with that
               surface.
 
            [0005] One prior fishbox which has been devised to assist drainage of the melt-water from
               the centre of the box is described in UK Patent Specification No. 2104047. The fishbox
               therein described has a raised middle portion to the floor of the box, that is, it
               is generally convex as discussed above.
 
            [0006] It is an object of the present invention to provide an improved fishbox wherein some
               at least of the disadvantages of prior fishboxes are reduced or eliminated.
 
            [0007] The fishbox according to the present invention has the conventional unitary structure
               of a generally rectanguar base and four walls upstanding from the base but it is characterised
               in that the base slopes downwardly from its ends towards its longitudinally central
               region and further slopes downwardly from that central region towards a zone in the
               middle of the length of one or both of the longer sides of the base. Thus, in longitudinal
               cross-section, the base of the fishbox slopes downwarly towards the centre of the
               box but, in transverse cross-section in the region of the box centre, the fishbox
               slopes downwardly towards one or both of the box sides. Preferably the transverse
               cross-section is generally symmetrical such that the base is higher in the middle
               and slopes downwardly towards both sides.
 
            [0008] It can be seen that the fishbox of the invention adopts the unexpected approach of
               draining its liquid contents firstly 
towards the the centre from the ends of the box (unlike prior fishboxes rich drain the liquid
               from the centre towards the ends) and only then from the central region towards one
               or both of the box sides. In a preferred form of the box, the liquid is drained as
               aforesaid to the two sides of the box and is then drained along those sides towards
               the box ends in open channels extending along the sides of the base.
 
            [0009] The fishbox according to the present invention has the very important merit that
               the base of the box is already generally concave from above and is therefore not subject
               to the possibility of distortion under the weight of the contents of the box, but
               still drains the liquid contents away from the centre of the box towards one or more
               positions at rich they can be drained out of the fishbox in any desired manner.
 
            [0010] The various slopes of the base and channels referred to above may be plane or curved
               slopes and the lines of intersection of the different slopes may be rounded or angular.
               It is envisaged that the slopes will in any case be relatively shallow, for example
               not exceeding five degrees relative to the horizontal, and the lines of intersection
               will therefore not be acute. In the preferred embodiment described below and illustrated
               in the accompagnying drawings, the inclination of the base towards the centre as seen
               in longitudinal cross-section is of the order of two degrees and the outward inclination
               in transverse section is only one degree. The inclination of the drainage channels
               along the sides of the base towards the ends is of the same general order of about
               one degree only.
 
            [0011] although the base is inherently not liable to the distortion to which upwardly-convex
               bases are liable, it may be given additional strength, if desired, by the provision
               of a transverse rib on the underside of the box in the region of the lateral drainage
               slope.
 
            [0012] The invention will now be further described with reference to the accompagnying drawings,
               which illustrate, by way of example only, one preferred embodiment of the improved
               fishbox according to the present invention and wherein:-
               
               
Fig. 1 is a plan view of the box;
               Fig. 2 is a longitudinal sectional view along the line II-II of Fig. 1;
               Fig. 3 is a transverse sectional view along the line III-III of Fig. 1; and
               Fig. 4 is an elevation from one side of the box.
 
            [0013] The illustrated fishbox is a one-piece product formed by injection moulding in plastics.
               It is in the form of a generally rectangular, open box having a base 10, end-walls
               11 and 12 and side-walls 13 and 14. While the central volume of the box, in which
               the fish are stored, is wholly symmetrical in longitudinal and transverse sectional
               view (Figs. 2 and 3 respectively), the external structure of the box differs between
               its two ends, as seen in Fig. 1. This difference, while permetting boxes to be nested
               when being transported empty, allows superimposed boxes to be stacked un-nested above
               each other when alternate boxes in a stack are turned through 180 degrees about a
               vertical axis.
 
            [0014] As shown in Figs. 2, the base 10 of the fishbox is inclined inwardly towards the
               centre of the length when viewed from the side. At that centre a shallow bracing rib
               15 imparts additional strength to the base. The inclination of the two halves of the
               box in this view is approximately two degrees to the horizontal. Thus water draining
               through the box contents down to the base drains towards the centre of the length
               of the base. As shown in the tranverse cross-sectional view of Fig. 3, at this central
               point the base tapers outwardly towards the sides of the box, at an inclination of
               the order of one degree to the horizontal. Thus water draining to the centre of the
               length of the box from its ends in turn drains outwardly towards the sides of the
               box.
 
            [0015] Shallow longitudinal channels 16 and 17 extend along the sides of the base at the
               foot of the side walls 13 and 14 respectively. These channels in turn slope from the
               centre of their lengths down towards the ends of the box, the inclination of the channel
               halves being of the order of one degree relative to the horizontal. At the ends of
               the channels 16, 17 are drain holes 18 and 19. In the side view of the fishbox illustrated
               in Fig. 4, the interior slope of the box base 10 towards the centre from its ends
               is hidden by the side wall 14, of which the external lower edge follows the slope
               of the channel 17 towards its ends.
 
            [0016] Thus all surplus liquid drainig to the base of the illustrated fishbox eventually
               flows out of the drain holes 18 and 19 in the base of the box. Below these drain holes
               the liquid is led by short inclined surfaces 20 and 21 respectively to overflow from
               the end walls away from the box, without draining or spilling on to lower boxes in
               a stack.
 
          
         
            
            1. A fishbox having a unitary structure comprising a generally rectangular base (10)
               and four walls (11, 12, 13, 14) upstanding from the base, characterised in that said
               base (10) slopes downwardly from its ends towards its longitudinally central region
               and further slopes downwardly from that central region towards a zone in the middle
               of the length of one or both of the longer sides of the base.
 
            2. A fishbox according to claim 1, characterised in that the base (10) is generally symmetrical
               in transverse section in said central region such that the base is higher in the middle
               and slopes downwardly towards both of said longer sides.
 
            3. A fishbox according to claim 2, characterised by open channels (16, 17) extending
               along said longer sides of the base.
 
            4. A fishbox as according to claim 3, characterised in that said open channels (16, 17)
               slope downwardly towards the ends of the base.
 
            5. A fishbox according to any of the preceding claims, characterised in that the angle
               of slope of each of the sloping surfaces is not greater than five degrees relative
               to the horizontal.
 
            6. A fishbox according to claim 5, characterised in that said angle of slope is not greater
               than two degrees relative to the horizontal.
 
            7. A fishbox according to any of the preceding claims, characterised by a transverse
               rib (15) on the underside of the base (10) in said central region of the base.